Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/17/14
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 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
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...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 COLUMBIA SC
745 PM EDT TUE SEP 16 2014
.SYNOPSIS...
A COLD FRONT IN THE MOUNTAINS THIS AFTERNOON WILL MOVE INTO THE
FORECAST AREA LATE TONIGHT. THE FRONT WILL BE IN THE COASTAL PLAIN
WEDNESDAY AND OFF THE COAST THURSDAY. HIGH PRESSURE WILL BRING
DRY WEATHER AND BELOW NORMAL TEMPERATURES FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE SURFACE COLD FRONT CONTINUES TO SLOWLY PUSH SOUTHWARD THROUGH
NORTHERN NORTH CAROLINA TO NEAR ASHEVILLE INTO NORTH CENTRAL
GEORGIA. AFTERNOON CONVECTION DEVELOPED ALONG THE COASTAL PLAIN
WHERE THE SEA BREEZE HELP TRIGGER CONVECTION WHERE DEEPER MOISTURE
RESIDED...WHILE ADDITIONAL STORMS FIRED IN THE VICINITY OF THE
FRONT AIDED BY UPPER SUPPORT FROM SHORTWAVE ENERGY MOVING ACROSS
EASTERN TENNESSEE THROUGH THE BASE OF THE BROAD UPPER TROUGH.
CURRENT RADAR IMAGERY SHOWS STORMS ALL AROUND THE FORECAST AREA
BUT ONLY SOME PERSISTANT SLOW MOVING SHOWERS IN FAR EASTERN
ORANGEBURG COUNTY. SEVERE STORMS MOVING SOUTHEASTWARD TOWARD
CHESTERFIELD AND NEWBERRY COUNTIES WILL NEED TO BE MONITORED INTO
THIS EVENING AS THEY HAVE NOT SHOWN MUCH WEAKENING OVER THE PAST
HOUR...LIKELY DUE TO UPPER SUPPORT RELATED TO THE UPPER TROUGH.
WILL HOLD ON TO SOME CHANCE POPS ACROSS THE NORTHERN AND WESTERN
MIDLANDS THROUGH 03Z AS HRRR INDICATES SOME CONTINUED CONVECTION
POSSIBLE THROUGH LATE EVENING IN THAT AREA. THE FRONT WILL PUSH
THROUGH THE AREA OVERNIGHT AND WILL KEEP SLIGHT CHANCE POPS UNTIL
THE FRONT PUSHES THROUGH. OVERNIGHT LOWS WILL LIKELY BE IMPACTED
BY ANY DEBRIS CLOUDS AND POSSIBLE STRATUS DEVELOPMENT BUT SHOULD
BE COOLER THAN TUESDAY MORNING...ESPECIALLY IN THE NORTHERN AND
WESTERN MIDLANDS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THE COLD FRONT IS FORECAST TO MOVE SOUTH OF THE CSRA BY SUNRISE
WEDNESDAY. AN UPPER LEVEL TROUGH OVER THE EASTERN THIRD OF THE
NATION WILL DEEPEN THROUGH THURSDAY AS A SERIES OF DISTURBANCES
CROSS THE AREA IN THE BASE OF THE TROUGH. MODERATE INSTABILITY
COUPLED WITH THE PASSAGE OF ONE SUCH DISTURBANCE WILL HOLD A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA WEDNESDAY INTO
WEDNESDAY NIGHT. DRIER AIR WILL BE WORKING ITS WAY ACROSS THE
FORECAST AREA FROM THE NORTHWEST...SO THE BEST CHANCE FOR SHOWERS
AND STORMS WILL BE ACROSS THE EASTERN MIDLANDS. AFTERNOON HIGHS WILL
BE IN THE UPPER 70S NORTH TO UPPER 80S SOUTH ON WEDNESDAY.
OVERNIGHT LOWS WILL BE IN THE LOWER TO MIDDLE 60S.
A LARGE AREA OF SURFACE HIGH PRESSURE CENTERED OVER THE GREAT
LAKES REGION WILL BUILD INTO THE CAROLINAS AND GEORGIA THURSDAY.
DRY WEATHER IS FORECAST GIVEN SHALLOW MOISTURE AND COLD ADVECTION.
KEPT AFTERNOON HIGHS IN THE UPPER 70S TO MIDDLE 80S WITH
OVERNIGHT LOWS MAINLY IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
DRY HIGH PRESSURE WILL REIGN OVER THE WEEKEND. A COOL NORTHEAST
FLOW WILL BRING BELOW NORMAL TEMPERATURES FRIDAY THROUGH SUNDAY.
HAVE FORECAST HIGHS IN THE MID 70S TO LOWER 80S WITH LOWS IN THE
MID 50S TO LOWER 60S.
THE NEXT COLD FRONT WILL AFFECT THE AREA IN THE MONDAY-TUESDAY
TIME-FRAME. KEPT LOW CHANCE POPS MONDAY AND TUESDAY. NEAR NORMAL
TEMPERATURES IN THE LOW TO MID 80S ARE EXPECTED MONDAY AHEAD OF THE
COLD FRONT. SHOULD SEE COOLER READINGS IN THE MID 70S TO LOWER 80S
TUESDAY AS THE FRONT PUSHES SOUTH OF THE AREA.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR CONDITIONS EARLY IN THE TAF PERIOD BUT CONVERGENCE
AHEAD OF AN APPROACHING COLD FRONT MAY SUPPORT THUNDERSTORMS MOVING
THROUGH THE AREA THIS EVENING. 88D REGIONAL RADAR SHOWS A COUPLE OF
STORMS...ONE ACROSS LAURENS COUNTY MOVING TOWARD THE MIDLANDS AND
ANOTHER ACROSS UNION COUNTY NC HEADING TOWARD THE NORTHERN
MIDLANDS/PEE DEE REGION. THE HIGH-RESOLUTION MODELS INDICATED THE
POTENTIAL FOR WIDELY SCATTERED COVERAGE THROUGH THE EVENING HOURS UP
UNTIL MIDNIGHT. THUNDERSTORMS ARE STILL NOT INCLUDED IN ANY OF THE
AREA TAFS...HOWEVER WILL NEED TO MONITOR THE STORM IN LAURENS COUNTY
FOR THE COLUMBIA METRO AREA. HIGH LOW-LEVEL MOISTURE ASSOCIATED WITH
WEAK CONVERGENCE NEAR THE FRONT PLUS DRY AIR ALOFT WITH LIGHT WIND
SHOULD SUPPORT AREAS OF FOG DURING THE EARLY MORNING HOURS
WEDNESDAY. MOST OF THE NAM AND GFS MOS SUPPORTED IFR CONDITIONS
DEVELOPING. HEATING AND MIXING SHOULD RESULT IN SOME IMPROVEMENT
LATER IN THE MORNING AS CONDITIONS RETURN TO VFR BY 15Z.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MAINLY DURING
THE LATE NIGHT AND EARLY MORNING IN STRATUS AND OR FOG.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
NEAR TERM...HC
AVIATION...LCV
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.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
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:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
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 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
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
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
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
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
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
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
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
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
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
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
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
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
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
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:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
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 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 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 GOODLAND KS
827 PM MDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 823 PM MDT TUE SEP 16 2014
BASED ON LATEST MODEL DATA AND SINCE THERE HAS NOT BEEN ANY FOG
DEVELOPMENT OVER THE LAST 3 MORNINGS WHEN MODELS WERE FORECASTING
FOG...HAVE CUT BACK ON THE AREA/COVERAGE OF FOG FOR THE
OVERNIGHT/MORNING HOURS. DID KEEP A MENTION OF FOG IN THE FORECAST
WHERE THE SREF HAS ATLEAST 50 PERCENT CONFIDENCE OF LESS THAN
A MILE VISIBILITY. AM NOT TOO CONCERNED AT THIS TIME ABOUT
REDUCED VISIBILITIES IF FOG DOES DEVELOP...BUT WILL SEE HOW THE
NIGHT GOES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 147 PM MDT TUE SEP 16 2014
AS OF 2 PM CDT...1 PM MDT...SKIES ACROSS THE TRI-STATE AREA WITH THE
REMAINING EXCEPTION OF ERODING STRATUS EAST OF A MCCOOK NEBRASKA TO
GOVE KANSAS LINE. TEMPERATURES WERE IN THE MID 70S TO MID 80S WHERE
SKIES HAVE CLEARED AND IN THE UPPER 60S TO LOW 70S WHERE STRATUS
REMAINS. WINDS WERE FROM THE SOUTH TO SOUTHWEST AT 10 TO 15 MPH...
GUSTING AS HIGH AS 25 MPH. A LEE TROUGH WAS LOCATED OVER NORTHEAST
COLORADO...SLOWLY PROGRESSING EAST INTO SOUTHWEST NEBRASKA. NO
SIGNIFICANT WEATHER DISTURBANCES WERE NOTED MOVING TOWARDS THE TRI-
STATE AREA.
FOR TONIGHT INTO TOMORROW...MAIN FORECAST CONCERN IS THE CHANCE FOR
FOG LATE TONIGHT/EARLY WEDNESDAY MORNING. BASED ON THE ANTICIPATED
LOCATION OF THE LEE TROUGH...POOLING MOISTURE EAST OF THE TROUGH AND
LIGHT/CALM WINDS...LIMITED THE POTENTIAL FOG TO PORTIONS OF
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. THE BEST CHANCES FOR FOG
SHOULD RESIDE NORTH AND EAST OF A LINE FROM STRATTON NEBRASKA TO
HOXIE TO HILL CITY KANSAS. IT IS INTERESTING TO NOTE THAT THE
NAM...WRF NMM...AND THE RUC13 INDICATE A POTENTIAL FOR DENSE FOG.
FUTURE SHIFTS WILL NEED TO MONITOR THIS THREAT BUT FOR NOW...DID NOT
PLACE DENSE WORDING INTO THE GRIDS.
FOR TOMORROW...WARMER WEATHER IS ANTICIPATED REGION-WIDE AS MOST OF
THE AREA SHOULD REMAIN FREE OF CLOUD COVER AND LOCATIONS THAT
EXPERIENCE FOG SHOULD SEE FOG LIFT AND DISSIPATE MUCH QUICKER THAN
STRATUS TODAY. ONE ITEM TO NOTE IS THE ECMWF...NAM12 AND WRF-NMM
DEVELOP A COUPLE SHOWERS/THUNDERSTORMS OVER EAST CENTRAL COLORADO
AND WEST CENTRAL KANSAS. INSTABILITY IS AROUND 1000-1500 J/KG OF
CAPE. HOWEVER...WITH A STRONG CAPE IN PLACE...WEAK SURFACE
CONVERGENCE AND LITTLE INDICATION OF A STRONG ENOUGH SHORTWAVE TO
OVERCOME THE CAP...DID NOT FEEL CONFIDENT ENOUGH TO MENTION A CHANCE
OF THUNDERSTORMS TOMORROW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM MDT TUE SEP 16 2014
WEDNESDAY NIGHT-THURSDAY NIGHT...UPPER RIDGE AXIS SHIFTS EAST OVER
THE AREA THURSDAY THEN SLOWLY EAST THURSDAY NIGHT. NAM MODEL HAS
BACKED OFF ON WESTWARD PUSH OF FRONTAL BOUNDARY AND POST-FRONTAL
STRATUS WEDNESDAY NIGHT...NOW LIMITING IT TO AREAS ACROSS FAR
SOUTHWEST NEBRASKA TO NORTON AND HILL CITY AREAS...SIMILAR TO THE
06Z GFS. NAM VISIBILITY FORECASTS FOR FOG IN THE STRATUS HAVE BEEN
HORRIBLE THE PAST WEEK OR SO...OVERDOING IT SIGNIFICANTLY.
HOWEVER...WITH A LIGHT EAST WIND VS SOUTHERLY THE PAST FEW POTENTIAL
EVENTS CANT RULE OUT SOME FOG SO HAVE KEPT IT GOING BUT BACKED OFF
COVERAGE JUST A BIT.
SOME ELEVATED THUNDERSTORMS POSSIBLE THROUGH MIDNIGHT WEDNESDAY
NIGHT FROM MCCOOK TO HILL CITY AND POINTS EAST WITH DECREASING
CHANCES SHORTLY AFTER AS INSTABILITY AXIS SLOWLY SHIFTS EAST.
SUNNY/MOSTLY SUNNY AND DRY THURSDAY WITH MOSTLY CLEAR CONDITIONS
THURSDAY NIGHT. A FEW CLOUDS MAY CREEP INTO THE FAR SOUTH AND
SOUTHWEST PARTS OF THE AREA HEAD OF (AS OF THIS WRITING) TROPICAL
STORM ODILE.
LOWS WEDNESDAY NIGHT IN THE MID 50S TO LOW 60S...WARMING A FEW
DEGREES FOR THURSDAY NIGHT. HIGHS THURSDAY MID 80S TO AROUND 90/LOW
90S.
FRIDAY-FRIDAY NIGHT...MOISTURE ASSOCIATED WITH (AS OF THIS WRITING)
TROPICAL STORM ODILE FORECAST TO REACH AREAS GENERALLY ALONG AND
SOUTH OF THE INTERSTATE BY 00Z SATURDAY WITH THE NAM/ECMWF FURTHEST
NORTH AND GFS QUITE A BIT TO THE SOUTH...NOT EVEN REACHING KANSAS.
FOR THIS FORECAST CYCLE HAVE TRIMMED BACK ON NORTHWARD EXTENT OF
PRECIPITATION CHANCES BY 18Z TO AREAS SOUTH OF A TRIBUNE AND LOETI
LINE. FOR FRIDAY NIGHT GENERAL IDEA IS FOR ODILES MOISTURE TO
CONTINUE TOWARD NORTON AND HILL CITY BY 06Z BEFORE EXITING TO THE
EAST AS AN UPPER TROUGH APPROACHES FROM THE NORTHWEST.
HIGHS IN THE 80S. LOWS IN THE MID 50S TO LOW 60S...COOLEST IN FAR
EASTERN COLORADO.
SATURDAY...MID AND HIGH CLOUDS INCREASE FROM THE NORTHWEST
ASSOCIATED UPPER TROUGH PASSAGE. PLENTY OF LOW CLOUDS REMAIN ACROSS
THE SOUTHEAST HALF OF THE AREA DURING THE MORNING BEFORE DECREASING
FROM NORTHWEST TO SOUTHEAST WITH THE TROUGH. ENOUGH INSTABILITY
PRESENT TO WARRANT A SLIGHT CHANCE OF THUNDERSTORMS. DRY WEATHER
EXPECTED SATURDAY NIGHT. HIGHS IN THE MID 70S TO LOW 80S. LOWS IN
THE LOW TO MID 50S.
SUNDAY...DRY WEATHER EXPECTED. HIGHS IN THE MID TO UPPER 70S
WITH LOWS IN THE LOW TO MID 50S.
MONDAY-TUESDAY...WILL BE WATCHING MOISTURE/CLOUDINESS WORKS ITS WAY
TOWARD THE WESTERN 1/2 OF THE AREA AHEAD OF AN UPPER LOW PRESSURE
SYSTEM MAKING ITS WAY INTO THE GREAT BASIN AREA FROM THE SOUTHWEST.
MAY SEE A FEW SHOWERS/THUNDERSTORMS GENERALLY ALONG/WEST OF THE
CO/KS BORDER TUESDAY.
HIGHS BOTH DAYS IN THE 70S WITH LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 525 PM MDT TUE SEP 16 2014
VFR TO MVFR CONDITIONS FORECAST FOR THE 0Z TAFS. BIGGEST CHALLENGE
WILL BE HOW LOW TO GO WITH THE CEILINGS/VIS TOWARD SUNRISE FOR
KMCK. WAS TOLD THAT DESPITE THE NAM MODEL FORECASTING DENSE FOG
THE LAST SEVERAL DAYS IN A ROW NO FOG HAS DEVELOPED. AM NOT SURE
WHAT THE OTHER NEAR TERM MODELS WERE SHOWING...BUT SINCE THERE
WILL NOT BEEN MUCH OF A CHANGE IN AIRMASS COMPARED TO THIS MORNING
WHEN ONLY MVFR CEILINGS DEVELOP. THEREFORE WILL SIMPLY GO WITH
PERSISTENCE AT THIS TIME AND SEE WHAT THE LATEST DATA SAYS FOR
THE NEXT SET OF TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...RRH
LONG TERM...99
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
534 PM MDT TUE SEP 16 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 147 PM MDT TUE SEP 16 2014
AS OF 2 PM CDT...1 PM MDT...SKIES ACROSS THE TRI-STATE AREA WITH THE
REMAINING EXCEPTION OF ERODING STRATUS EAST OF A MCCOOK NEBRASKA TO
GOVE KANSAS LINE. TEMPERATURES WERE IN THE MID 70S TO MID 80S WHERE
SKIES HAVE CLEARED AND IN THE UPPER 60S TO LOW 70S WHERE STRATUS
REMAINS. WINDS WERE FROM THE SOUTH TO SOUTHWEST AT 10 TO 15 MPH...
GUSTING AS HIGH AS 25 MPH. A LEE TROUGH WAS LOCATED OVER NORTHEAST
COLORADO...SLOWLY PROGRESSING EAST INTO SOUTHWEST NEBRASKA. NO
SIGNIFICANT WEATHER DISTURBANCES WERE NOTED MOVING TOWARDS THE TRI-
STATE AREA.
FOR TONIGHT INTO TOMORROW...MAIN FORECAST CONCERN IS THE CHANCE FOR
FOG LATE TONIGHT/EARLY WEDNESDAY MORNING. BASED ON THE ANTICIPATED
LOCATION OF THE LEE TROUGH...POOLING MOISTURE EAST OF THE TROUGH AND
LIGHT/CALM WINDS...LIMITED THE POTENTIAL FOG TO PORTIONS OF
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. THE BEST CHANCES FOR FOG
SHOULD RESIDE NORTH AND EAST OF A LINE FROM STRATTON NEBRASKA TO
HOXIE TO HILL CITY KANSAS. IT IS INTERESTING TO NOTE THAT THE
NAM...WRF NMM...AND THE RUC13 INDICATE A POTENTIAL FOR DENSE FOG.
FUTURE SHIFTS WILL NEED TO MONITOR THIS THREAT BUT FOR NOW...DID NOT
PLACE DENSE WORDING INTO THE GRIDS.
FOR TOMORROW...WARMER WEATHER IS ANTICIPATED REGION-WIDE AS MOST OF
THE AREA SHOULD REMAIN FREE OF CLOUD COVER AND LOCATIONS THAT
EXPERIENCE FOG SHOULD SEE FOG LIFT AND DISSIPATE MUCH QUICKER THAN
STRATUS TODAY. ONE ITEM TO NOTE IS THE ECMWF...NAM12 AND WRF-NMM
DEVELOP A COUPLE SHOWERS/THUNDERSTORMS OVER EAST CENTRAL COLORADO
AND WEST CENTRAL KANSAS. INSTABILITY IS AROUND 1000-1500 J/KG OF
CAPE. HOWEVER...WITH A STRONG CAPE IN PLACE...WEAK SURFACE
CONVERGENCE AND LITTLE INDICATION OF A STRONG ENOUGH SHORTWAVE TO
OVERCOME THE CAP...DID NOT FEEL CONFIDENT ENOUGH TO MENTION A CHANCE
OF THUNDERSTORMS TOMORROW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM MDT TUE SEP 16 2014
WEDNESDAY NIGHT-THURSDAY NIGHT...UPPER RIDGE AXIS SHIFTS EAST OVER
THE AREA THURSDAY THEN SLOWLY EAST THURSDAY NIGHT. NAM MODEL HAS
BACKED OFF ON WESTWARD PUSH OF FRONTAL BOUNDARY AND POST-FRONTAL
STRATUS WEDNESDAY NIGHT...NOW LIMITING IT TO AREAS ACROSS FAR
SOUTHWEST NEBRASKA TO NORTON AND HILL CITY AREAS...SIMILAR TO THE
06Z GFS. NAM VISIBILITY FORECASTS FOR FOG IN THE STRATUS HAVE BEEN
HORRIBLE THE PAST WEEK OR SO...OVERDOING IT SIGNIFICANTLY.
HOWEVER...WITH A LIGHT EAST WIND VS SOUTHERLY THE PAST FEW POTENTIAL
EVENTS CANT RULE OUT SOME FOG SO HAVE KEPT IT GOING BUT BACKED OFF
COVERAGE JUST A BIT.
SOME ELEVATED THUNDERSTORMS POSSIBLE THROUGH MIDNIGHT WEDNESDAY
NIGHT FROM MCCOOK TO HILL CITY AND POINTS EAST WITH DECREASING
CHANCES SHORTLY AFTER AS INSTABILITY AXIS SLOWLY SHIFTS EAST.
SUNNY/MOSTLY SUNNY AND DRY THURSDAY WITH MOSTLY CLEAR CONDITIONS
THURSDAY NIGHT. A FEW CLOUDS MAY CREEP INTO THE FAR SOUTH AND
SOUTHWEST PARTS OF THE AREA HEAD OF (AS OF THIS WRITING) TROPICAL
STORM ODILE.
LOWS WEDNESDAY NIGHT IN THE MID 50S TO LOW 60S...WARMING A FEW
DEGREES FOR THURSDAY NIGHT. HIGHS THURSDAY MID 80S TO AROUND 90/LOW
90S.
FRIDAY-FRIDAY NIGHT...MOISTURE ASSOCIATED WITH (AS OF THIS WRITING)
TROPICAL STORM ODILE FORECAST TO REACH AREAS GENERALLY ALONG AND
SOUTH OF THE INTERSTATE BY 00Z SATURDAY WITH THE NAM/ECMWF FURTHEST
NORTH AND GFS QUITE A BIT TO THE SOUTH...NOT EVEN REACHING KANSAS.
FOR THIS FORECAST CYCLE HAVE TRIMMED BACK ON NORTHWARD EXTENT OF
PRECIPITATION CHANCES BY 18Z TO AREAS SOUTH OF A TRIBUNE AND LOETI
LINE. FOR FRIDAY NIGHT GENERAL IDEA IS FOR ODILES MOISTURE TO
CONTINUE TOWARD NORTON AND HILL CITY BY 06Z BEFORE EXITING TO THE
EAST AS AN UPPER TROUGH APPROACHES FROM THE NORTHWEST.
HIGHS IN THE 80S. LOWS IN THE MID 50S TO LOW 60S...COOLEST IN FAR
EASTERN COLORADO.
SATURDAY...MID AND HIGH CLOUDS INCREASE FROM THE NORTHWEST
ASSOCIATED UPPER TROUGH PASSAGE. PLENTY OF LOW CLOUDS REMAIN ACROSS
THE SOUTHEAST HALF OF THE AREA DURING THE MORNING BEFORE DECREASING
FROM NORTHWEST TO SOUTHEAST WITH THE TROUGH. ENOUGH INSTABILITY
PRESENT TO WARRANT A SLIGHT CHANCE OF THUNDERSTORMS. DRY WEATHER
EXPECTED SATURDAY NIGHT. HIGHS IN THE MID 70S TO LOW 80S. LOWS IN
THE LOW TO MID 50S.
SUNDAY...DRY WEATHER EXPECTED. HIGHS IN THE MID TO UPPER 70S
WITH LOWS IN THE LOW TO MID 50S.
MONDAY-TUESDAY...WILL BE WATCHING MOISTURE/CLOUDINESS WORKS ITS WAY
TOWARD THE WESTERN 1/2 OF THE AREA AHEAD OF AN UPPER LOW PRESSURE
SYSTEM MAKING ITS WAY INTO THE GREAT BASIN AREA FROM THE SOUTHWEST.
MAY SEE A FEW SHOWERS/THUNDERSTORMS GENERALLY ALONG/WEST OF THE
CO/KS BORDER TUESDAY.
HIGHS BOTH DAYS IN THE 70S WITH LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 525 PM MDT TUE SEP 16 2014
VFR TO MVFR CONDITIONS FORECAST FOR THE 0Z TAFS. BIGGEST CHALLENGE
WILL BE HOW LOW TO GO WITH THE CEILINGS/VIS TOWARD SUNRISE FOR
KMCK. WAS TOLD THAT DESPITE THE NAM MODEL FORECASTING DENSE FOG
THE LAST SEVERAL DAYS IN A ROW NO FOG HAS DEVELOPED. AM NOT SURE
WHAT THE OTHER NEAR TERM MODELS WERE SHOWING...BUT SINCE THERE
WILL NOT BEEN MUCH OF A CHANGE IN AIRMASS COMPARED TO THIS MORNING
WHEN ONLY MVFR CEILINGS DEVELOP. THEREFORE WILL SIMPLY GO WITH
PERSISTENCE AT THIS TIME AND SEE WHAT THE LATEST DATA SAYS FOR
THE NEXT SET OF TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...99
AVIATION...JTL
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 JACKSON KY
1135 PM EDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 1135 PM EDT TUE SEP 16 2014
ADJUSTED OVERNIGHT LOWS BASED ON CURRENT TRENDS...GENERALLY A LITTLE
COOLER IN THE NORTH. AFTERNOON POST FRONTAL CLOUDS CONTINUE TO ERODE
AS SUBSIDENCE ALOFT DRIES OUT THE ATMOSPHERE JUST ABOVE THE BOUNDARY
LAYER. CONSEQUENTLY AS SKIES CLEAR...LOWER STRATUS AND FOG HAVE BEEN
REDEVELOPING DUE TO NEAR IDEAL RADIATIVE CONDITIONS ALOFT AT THE TOP
OF THE RESIDUAL MOIST BOUNDARY/SURFACE LAYER OVER OUR FORECAST AREA.
BEEFED UP FOG IN THE GRIDS AND ZONES. ATTM NOT EXACTLY SURE HOW
WIDESPREAD FOG FORMATION WILL BE OVERNIGHT DUE TO EVENTUAL STRENGTH
OF SFC WINDS AND MIXING. AFTER DISCUSSIONS WITH NEIGHBORS...DECIDED
TO ISSUE A SPECIAL WEATHER STATEMENT TO HIGHLIGHT FOG POTENTIAL.
UPDATE ISSUED AT 858 PM EDT TUE SEP 16 2014
QUICK UPDATE TO THE ZONES TO REMOVE SPRINKLES. BROUGHT GRIDS IN LINE
WITH HOURLY OBS...TEMPS DROPPING A BIT FASTER THAN ANTICIPATED WITH
PARTIAL CLEARING. HOWEVER OVERNIGHT MINS STILL LOOK ON TRACK FOR NOW.
UPDATE ISSUED AT 713 PM EDT TUE SEP 16 2014
FORECAST IS IN GOOD SHAPE. TWEAKED GRIDS TO HOURLY OBSERVATIONS.
STILL SEEING SOME VERY LIGHT ECHOS ACROSS THE SOUTHEAST. THEREFORE
WILL HOLD OFF ON ANY UPDATE TO THE ZFP FOR A BIT LONGER BEFORE
REMOVING LIGHT SPRINKLE ACTIVITY. REGIONAL SATELLITE IS SHOWING DECENT
AMOUNT OF CLOUD EROSION AS DRY AIR FROM DEVELOPING SUBSIDENCE
INVERSION ALOFT MIXES INTO THE TOP OF THE BOUNDARY LAYER. RELATIVELY
HIGH SFC DEW POINTS REMAIN HOWEVER. CONCERN IS THAT WITH STRONG
SUBSIDENCE AND THEREFORE DRYING TAKING PLACE JUST ABOVE THE BOUNDARY
LAYER...RADIATIVE COOLING WILL BE THE CATALYST FOR LOW STRATUS AND
FOG TO REDEVELOP OVERNIGHT. WILL KEEP A CLOSE EYE ON OBSERVATIONS
THROUGH THE EVENING IN CASE A HEADLINE IS NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 350 PM EDT TUE SEP 16 2014
19Z SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXITING FAR SOUTHEAST
KENTUCKY AS A COOL AND DRY AREA OF HIGH PRESSURE PUSHES DEEPER INTO
THE OHIO VALLEY. BEHIND THIS BOUNDARY...A FEW LIGHT SHOWERS AND
PLENTY OF SPRINKLES/DRIZZLE REMAIN OVER A GOOD PORTION OF THE CWA.
ON SATELLITE...THE LOW CLOUDS ARE BREAKING UP OVER THE SOUTHERN
PORTION OF EAST KENTUCKY WHILE THEY ARE HOLDING TIGHT OVER JKL AND
POINTS NORTH. THE EXTENSIVE CLOUD COVER AND POCKETS OF LIGHT PCPN
KEPT TEMPERATURES WELL BELOW NORMAL FOR THE DAY WITH READINGS
CURRENTLY RANGING FROM A CHILLY 60 DEGREES ALONG AND NORTH OF
INTERSTATE 64 WHILE SOME 70 DEGREE READINGS HAVE SHOWN UP TO THE
SOUTH THANKS TO PARTIAL SUNSHINE. DEW POINTS VARY FROM THE MID 50S
NORTH TO THE LOWER AND MIDDLE 60S SOUTH. LIGHT NORTH WINDS ARE ADDING
TO THE CHILL THROUGH MOST OF THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH EAST KENTUCKY STILL IN
THE GRIP OF A BROAD AND UNSEASONABLY DEEP TROUGH THROUGH THE EASTERN
HALF OF THE NATION. FAIRLY FAST NORTHWEST FLOW AT THE BASE OF THIS
TROUGH WILL KEEP A SERIES OF WEAK DISTURBANCES MOVING THROUGH EAST
KENTUCKY DURING THE SHORT TERM PORTION OF THE FORECAST. THE
HEALTHIEST OF THESE ACTUALLY PASSES THROUGH DURING THE DAY WEDNESDAY
WITH A KINK IN THE FLOW LINES. GIVEN THE MODEL SIMILARITIES ALOFT
HAVE GONE WITH A GENERAL BLEND WHILE FAVORING THE HRRR AND NAM12
THROUGH THE FIRST 18 TO 24 HOURS.
SENSIBLE WEATHER WILL FEATURE THE LINGERING SHOWERS AND POCKETS OF
SPRINKLES/DRIZZLE DRYING UP BY EARLY EVENING WITH SOME CLEARING
EXPECTED FOR A TIME. HOWEVER...THIS CLEARING...WITH LITTLE IN THE
WAY OF SFC WINDS...WILL LIKELY ALLOW AREAS OF DENSE FOG AND LOW
STRATUS TO DEVELOP...RESTRICTING VISIBILITY IN MOST PLACES ACROSS
EAST KENTUCKY BY DAWN. HAVE HIT THIS HARD IN THE GRIDS AND ALSO THE
HWO. WILL LEAVE IT TO LATER SHIFTS TO MONITOR THE CLEARING...
ADVECTION...AND PRELIMINARY FOG PRODUCTION FOR A POTENTIAL ADVISORY
OR SPS. ONCE THE FOG BURNS OFF ON WEDNESDAY MORNING SOME SUNSHINE CAN
BE EXPECTED... BUT THE UPPER LEVEL ENERGY WILL LIKELY BRING IN MORE
LOW AND MID LEVEL CLOUDS. IN FACT...CANNOT COMPLETELY RULE OUT SOME
MORE SPRINKLES OR A LIGHT SHOWER AS THIS WAVE MOVES BY ALOFT
WEDNESDAY AFTERNOON. FOR NOW...THOUGH...HAVE KEPT THE POPS JUST BELOW
MENTIONING. THE WAKE OF THIS WILL SET UP ANOTHER NIGHT OF AT LEAST
PARTIAL CLEARING ALONG WITH AREAS OF FOG...LOCALLY DENSE FORMING LATE
AT NIGHT. THIS SHOULD BE THE COLDER OF THE NIGHTS WITH SOME UPPER 40S
POSSIBLE IN THE VALLEYS THROUGH THE NORTHERN HALF OF THE AREA...AND
ELSEWHERE IF THE CLEARING AND FOG ALLOW IT.
AGAIN 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 NUDGE THE LOWS TONIGHT AND ESPECIALLY WEDNESDAY NIGHT FOR RIDGE
AND VALLEY DIFFERENCES. AS FOR POPS...ENDED UP HIGHER THAN MOS IN THE
NEAR TERM AND ALSO FOR LATER WEDNESDAY...OTHERWISE KEPT THE POPS LOW
SIMILAR TO THE GUIDANCE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 PM EDT TUE SEP 16 2014
THURSDAY MORNING STARTS THE EXTENDED PERIOD WITH AN AMPLIFIED UPPER
LEVEL PATTERN. STRONG TROUGHING WILL EXIST ACROSS MUCH OF THE
EASTERN THIRD OF THE CONUS...WHILE HIGH PRESSURE RIDGING REMAINS
PARKED ACROSS THE SOUTHWESTERN STATES. THIS PATTERN WILL REMAIN IN
PLACE THROUGH FRIDAY...BEFORE IT STARTS TO BREAK DOWN AND HEIGHTS
BEGIN TO BUILD ACROSS EASTERN KY INTO THE DAY SATURDAY. N/NW WINDS
WILL USHER IN COLD WINDS DURING THE DAY THURSDAY...WITH HIGHS ONLY
REACHING THE LOW TO MID 70S. THIS WILL NOT
CONTINUE...HOWEVER...AS A SHORTWAVE MOVES TOWARDS THE REGION DURING
THE DAY FRIDAY. AT THE SURFACE...A POTENT COLD FRONT WILL BE MAKING
ITS WAY FROM THE NORTHERN PLAINS TOWARDS KY...WITH SRLY WINDS
PULLING UP WARM AIR OUT AHEAD OF THE FRONT. THIS WILL RESULT IN
INCREASING TEMPERATURES FRIDAY...REACHING MORE SEASONABLE UPPER 70S
AND LOW 80S FOR BOTH FRIDAY AND SATURDAY.
THE FRONT WILL LOSE STRENGTH AS IT MOVES TOWARDS THE EASTERN KY
REGION AS UPPER LEVEL HEIGHTS CONTINUE TO BUILD INTO THE WEEKEND. BY
THE TIME THE SYSTEM REACHES EASTERN KY...THERE WILL BE VERY LITTLE
INSTABILITY LEFT...AS WELL AS VERY LITTLE CONCERN FOR PWAT VALUES.
MODELS ARE STILL SLIGHTLY DIFFERENT ON THE EXACT TIMING AND EXTENT
OF THE PRECIPITATION...SO WILL CONTINUE TO STICK CLOSE TO A MODEL
BLEND. AS SUCH...EXPECT THE PRECIP TO MOVE AHEAD OF THE FRONT AND
INTO EASTERN KY BETWEEN 12 AND 18Z SUNDAY...AND CONTINUE INTO EARLY
AFTERNOON MONDAY. DESPITE LACK OF INSTABILITY...NEIGHBORING OFFICES
CONTINUE TO FAVOR THE FACT THAT THE FRONTAL BOUNDARY LIFT ALONE MAY
BE ENOUGH TO INITIATE SOME THUNDER. AS SUCH...KEPT IN ONLY SLIGHT
MENTION OF THUNDER AS THE LINE MAKES IT THROUGH KY SUNDAY INTO
MONDAY...WITH THE EXCEPTION OF SUNDAY AFTERNOON...WHERE IT SEEMS THE
INCOMING FRONT WILL BRING A BRIEF PERIOD OF HEIGHTENED INSTABILITY
WITH AFTERNOON HEATING...AND THEREFORE CHANCES WERE INCLUDED.
TEMPS WILL COOL SUBSTANTIALLY BEHIND THE FRONTAL PASSAGE BY DURING
THE DAY MONDAY. UPPER LEVEL RIDGING WILL SLOWLY MOVE IN OVERHEAD
INTO THE DAY TUESDAY...WHILE AT THE SURFACE BROAD HIGH PRESSURE
TAKES CONTROL. SURFACE WINDS WILL BECOME MORE NORTHERLY...AS STRONG
W/NW WINDS ALOFT. THIS WILL RESULT IN THE RETURN OF ANOTHER
UNSEASONABLY COOL AIR MASS AND HIGH TEMPERATURES ONLY TOPPING OUT IN
THE LOW TO MID 70S. TEMPS WILL CONTINUE TO DETERIORATE BY THE DAY
TUESDAY...WITH HIGHS IN THE UPPER 60S TO AROUND 70S EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 757 PM EDT TUE SEP 16 2014
SOME IMPROVEMENT TO FLIGHT CONDITIONS THROUGH THE LATE AFTERNOON
HOURS...BUT EXPECT A RETURN TO LIFR CONDITIONS THROUGH THE OVERNIGHT
AS LOW STRATUS AND FOG REDEVELOPS ACROSS THE AREA. STAYED CLOSE TO
MODEL GUIDANCE...BRINGING ALL TAF SITES DOWN INTO MVFR TERRITORY
LATE THIS EVENING AND THEN TO LIFR LEVELS AFTER MIDNIGHT. WE SHOULD
SEE A GRADUAL IMPROVEMENT INTO THE DAY WEDNESDAY. WINDS THROUGH THE
PERIOD WILL BE GENERALLY LIGHT BUT PICK UP SOME...AROUND 5 KTS FROM
THE NORTH....NORTHWEST WEDNESDAY AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
858 PM EDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 858 PM EDT TUE SEP 16 2014
QUICK UPDATE TO THE ZONES TO REMOVE SPRINKLES. BROUGHT GRIDS IN LINE
WITH HOURLY OBS...TEMPS DROPPING A BIT FASTER THAN ANTICIPATED WITH
PARTIAL CLEARING. HOWEVER OVERNIGHT MINS STILL LOOK ON TRACK FOR NOW.
UPDATE ISSUED AT 713 PM EDT TUE SEP 16 2014
FORECAST IS IN GOOD SHAPE. TWEAKED GRIDS TO HOURLY OBSERVATIONS.
STILL SEEING SOME VERY LIGHT ECHOS ACROSS THE SOUTHEAST. THEREFORE
WILL HOLD OFF ON ANY UPDATE TO THE ZFP FOR A BIT LONGER BEFORE
REMOVING LIGHT SPRINKLE ACTIVITY. REGIONAL SATELLITE IS SHOWING DECENT
AMOUNT OF CLOUD EROSION AS DRY AIR FROM DEVELOPING SUBSIDENCE
INVERSION ALOFT MIXES INTO THE TOP OF THE BOUNDARY LAYER. RELATIVELY
HIGH SFC DEW POINTS REMAIN HOWEVER. CONCERN IS THAT WITH STRONG
SUBSIDENCE AND THEREFORE DRYING TAKING PLACE JUST ABOVE THE BOUNDARY
LAYER...RADIATIVE COOLING WILL BE THE CATALYST FOR LOW STRATUS AND
FOG TO REDEVELOP OVERNIGHT. WILL KEEP A CLOSE EYE ON OBSERVATIONS
THROUGH THE EVENING IN CASE A HEADLINE IS NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 350 PM EDT TUE SEP 16 2014
19Z SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXITING FAR SOUTHEAST
KENTUCKY AS A COOL AND DRY AREA OF HIGH PRESSURE PUSHES DEEPER INTO
THE OHIO VALLEY. BEHIND THIS BOUNDARY...A FEW LIGHT SHOWERS AND
PLENTY OF SPRINKLES/DRIZZLE REMAIN OVER A GOOD PORTION OF THE CWA.
ON SATELLITE...THE LOW CLOUDS ARE BREAKING UP OVER THE SOUTHERN
PORTION OF EAST KENTUCKY WHILE THEY ARE HOLDING TIGHT OVER JKL AND
POINTS NORTH. THE EXTENSIVE CLOUD COVER AND POCKETS OF LIGHT PCPN
KEPT TEMPERATURES WELL BELOW NORMAL FOR THE DAY WITH READINGS
CURRENTLY RANGING FROM A CHILLY 60 DEGREES ALONG AND NORTH OF
INTERSTATE 64 WHILE SOME 70 DEGREE READINGS HAVE SHOWN UP TO THE
SOUTH THANKS TO PARTIAL SUNSHINE. DEW POINTS VARY FROM THE MID 50S
NORTH TO THE LOWER AND MIDDLE 60S SOUTH. LIGHT NORTH WINDS ARE ADDING
TO THE CHILL THROUGH MOST OF THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH EAST KENTUCKY STILL IN
THE GRIP OF A BROAD AND UNSEASONABLY DEEP TROUGH THROUGH THE EASTERN
HALF OF THE NATION. FAIRLY FAST NORTHWEST FLOW AT THE BASE OF THIS
TROUGH WILL KEEP A SERIES OF WEAK DISTURBANCES MOVING THROUGH EAST
KENTUCKY DURING THE SHORT TERM PORTION OF THE FORECAST. THE
HEALTHIEST OF THESE ACTUALLY PASSES THROUGH DURING THE DAY WEDNESDAY
WITH A KINK IN THE FLOW LINES. GIVEN THE MODEL SIMILARITIES ALOFT
HAVE GONE WITH A GENERAL BLEND WHILE FAVORING THE HRRR AND NAM12
THROUGH THE FIRST 18 TO 24 HOURS.
SENSIBLE WEATHER WILL FEATURE THE LINGERING SHOWERS AND POCKETS OF
SPRINKLES/DRIZZLE DRYING UP BY EARLY EVENING WITH SOME CLEARING
EXPECTED FOR A TIME. HOWEVER...THIS CLEARING...WITH LITTLE IN THE
WAY OF SFC WINDS...WILL LIKELY ALLOW AREAS OF DENSE FOG AND LOW
STRATUS TO DEVELOP...RESTRICTING VISIBILITY IN MOST PLACES ACROSS
EAST KENTUCKY BY DAWN. HAVE HIT THIS HARD IN THE GRIDS AND ALSO THE
HWO. WILL LEAVE IT TO LATER SHIFTS TO MONITOR THE CLEARING...
ADVECTION...AND PRELIMINARY FOG PRODUCTION FOR A POTENTIAL ADVISORY
OR SPS. ONCE THE FOG BURNS OFF ON WEDNESDAY MORNING SOME SUNSHINE CAN
BE EXPECTED... BUT THE UPPER LEVEL ENERGY WILL LIKELY BRING IN MORE
LOW AND MID LEVEL CLOUDS. IN FACT...CANNOT COMPLETELY RULE OUT SOME
MORE SPRINKLES OR A LIGHT SHOWER AS THIS WAVE MOVES BY ALOFT
WEDNESDAY AFTERNOON. FOR NOW...THOUGH...HAVE KEPT THE POPS JUST BELOW
MENTIONING. THE WAKE OF THIS WILL SET UP ANOTHER NIGHT OF AT LEAST
PARTIAL CLEARING ALONG WITH AREAS OF FOG...LOCALLY DENSE FORMING LATE
AT NIGHT. THIS SHOULD BE THE COLDER OF THE NIGHTS WITH SOME UPPER 40S
POSSIBLE IN THE VALLEYS THROUGH THE NORTHERN HALF OF THE AREA...AND
ELSEWHERE IF THE CLEARING AND FOG ALLOW IT.
AGAIN 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 NUDGE THE LOWS TONIGHT AND ESPECIALLY WEDNESDAY NIGHT FOR RIDGE
AND VALLEY DIFFERENCES. AS FOR POPS...ENDED UP HIGHER THAN MOS IN THE
NEAR TERM AND ALSO FOR LATER WEDNESDAY...OTHERWISE KEPT THE POPS LOW
SIMILAR TO THE GUIDANCE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 PM EDT TUE SEP 16 2014
THURSDAY MORNING STARTS THE EXTENDED PERIOD WITH AN AMPLIFIED UPPER
LEVEL PATTERN. STRONG TROUGHING WILL EXIST ACROSS MUCH OF THE
EASTERN THIRD OF THE CONUS...WHILE HIGH PRESSURE RIDGING REMAINS
PARKED ACROSS THE SOUTHWESTERN STATES. THIS PATTERN WILL REMAIN IN
PLACE THROUGH FRIDAY...BEFORE IT STARTS TO BREAK DOWN AND HEIGHTS
BEGIN TO BUILD ACROSS EASTERN KY INTO THE DAY SATURDAY. N/NW WINDS
WILL USHER IN COLD WINDS DURING THE DAY THURSDAY...WITH HIGHS ONLY
REACHING THE LOW TO MID 70S. THIS WILL NOT
CONTINUE...HOWEVER...AS A SHORTWAVE MOVES TOWARDS THE REGION DURING
THE DAY FRIDAY. AT THE SURFACE...A POTENT COLD FRONT WILL BE MAKING
ITS WAY FROM THE NORTHERN PLAINS TOWARDS KY...WITH SRLY WINDS
PULLING UP WARM AIR OUT AHEAD OF THE FRONT. THIS WILL RESULT IN
INCREASING TEMPERATURES FRIDAY...REACHING MORE SEASONABLE UPPER 70S
AND LOW 80S FOR BOTH FRIDAY AND SATURDAY.
THE FRONT WILL LOSE STRENGTH AS IT MOVES TOWARDS THE EASTERN KY
REGION AS UPPER LEVEL HEIGHTS CONTINUE TO BUILD INTO THE WEEKEND. BY
THE TIME THE SYSTEM REACHES EASTERN KY...THERE WILL BE VERY LITTLE
INSTABILITY LEFT...AS WELL AS VERY LITTLE CONCERN FOR PWAT VALUES.
MODELS ARE STILL SLIGHTLY DIFFERENT ON THE EXACT TIMING AND EXTENT
OF THE PRECIPITATION...SO WILL CONTINUE TO STICK CLOSE TO A MODEL
BLEND. AS SUCH...EXPECT THE PRECIP TO MOVE AHEAD OF THE FRONT AND
INTO EASTERN KY BETWEEN 12 AND 18Z SUNDAY...AND CONTINUE INTO EARLY
AFTERNOON MONDAY. DESPITE LACK OF INSTABILITY...NEIGHBORING OFFICES
CONTINUE TO FAVOR THE FACT THAT THE FRONTAL BOUNDARY LIFT ALONE MAY
BE ENOUGH TO INITIATE SOME THUNDER. AS SUCH...KEPT IN ONLY SLIGHT
MENTION OF THUNDER AS THE LINE MAKES IT THROUGH KY SUNDAY INTO
MONDAY...WITH THE EXCEPTION OF SUNDAY AFTERNOON...WHERE IT SEEMS THE
INCOMING FRONT WILL BRING A BRIEF PERIOD OF HEIGHTENED INSTABILITY
WITH AFTERNOON HEATING...AND THEREFORE CHANCES WERE INCLUDED.
TEMPS WILL COOL SUBSTANTIALLY BEHIND THE FRONTAL PASSAGE BY DURING
THE DAY MONDAY. UPPER LEVEL RIDGING WILL SLOWLY MOVE IN OVERHEAD
INTO THE DAY TUESDAY...WHILE AT THE SURFACE BROAD HIGH PRESSURE
TAKES CONTROL. SURFACE WINDS WILL BECOME MORE NORTHERLY...AS STRONG
W/NW WINDS ALOFT. THIS WILL RESULT IN THE RETURN OF ANOTHER
UNSEASONABLY COOL AIR MASS AND HIGH TEMPERATURES ONLY TOPPING OUT IN
THE LOW TO MID 70S. TEMPS WILL CONTINUE TO DETERIORATE BY THE DAY
TUESDAY...WITH HIGHS IN THE UPPER 60S TO AROUND 70S EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 757 PM EDT TUE SEP 16 2014
SOME IMPROVEMENT TO FLIGHT CONDITIONS THROUGH THE LATE AFTERNOON
HOURS...BUT EXPECT A RETURN TO LIFR CONDITIONS THROUGH THE OVERNIGHT
AS LOW STRATUS AND FOG REDEVELOPS ACROSS THE AREA. STAYED CLOSE TO
MODEL GUIDANCE...BRINGING ALL TAF SITES DOWN INTO MVFR TERRITORY
LATE THIS EVENING AND THEN TO LIFR LEVELS AFTER MIDNIGHT. WE SHOULD
SEE A GRADUAL IMPROVEMENT INTO THE DAY WEDNESDAY. WINDS THROUGH THE
PERIOD WILL BE GENERALLY LIGHT BUT PICK UP SOME...AROUND 5 KTS FROM
THE NORTH....NORTHWEST WEDNESDAY AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
757 PM EDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 713 PM EDT TUE SEP 16 2014
FORECAST IS IN GOOD SHAPE. TWEAKED GRIDS TO HOURLY OBSERVATIONS.
STILL SEEING SOME VERY LIGHT ECHOS ACROSS THE SOUTHEAST. THEREFORE
WILL HOLD OFF ON ANY UPDATE TO THE ZFP FOR A BIT LONGER BEFORE
REMOVING LIGHT SPRINKLE ACTIVITY. REGIONAL SATELLITE IS SHOWING DECENT
AMOUNT OF CLOUD EROSION AS DRY AIR FROM DEVELOPING SUBSIDENCE
INVERSION ALOFT MIXES INTO THE TOP OF THE BOUNDARY LAYER. RELATIVELY
HIGH SFC DEW POINTS REMAIN HOWEVER. CONCERN IS THAT WITH STRONG
SUBSIDENCE AND THEREFORE DRYING TAKING PLACE JUST ABOVE THE BOUNDARY
LAYER...RADIATIVE COOLING WILL BE THE CATALYST FOR LOW STRATUS AND
FOG TO REDEVELOP OVERNIGHT. WILL KEEP A CLOSE EYE ON OBSERVATIONS
THROUGH THE EVENING IN CASE A HEADLINE IS NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 350 PM EDT TUE SEP 16 2014
19Z SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXITING FAR SOUTHEAST
KENTUCKY AS A COOL AND DRY AREA OF HIGH PRESSURE PUSHES DEEPER INTO
THE OHIO VALLEY. BEHIND THIS BOUNDARY...A FEW LIGHT SHOWERS AND
PLENTY OF SPRINKLES/DRIZZLE REMAIN OVER A GOOD PORTION OF THE CWA.
ON SATELLITE...THE LOW CLOUDS ARE BREAKING UP OVER THE SOUTHERN
PORTION OF EAST KENTUCKY WHILE THEY ARE HOLDING TIGHT OVER JKL AND
POINTS NORTH. THE EXTENSIVE CLOUD COVER AND POCKETS OF LIGHT PCPN
KEPT TEMPERATURES WELL BELOW NORMAL FOR THE DAY WITH READINGS
CURRENTLY RANGING FROM A CHILLY 60 DEGREES ALONG AND NORTH OF
INTERSTATE 64 WHILE SOME 70 DEGREE READINGS HAVE SHOWN UP TO THE
SOUTH THANKS TO PARTIAL SUNSHINE. DEW POINTS VARY FROM THE MID 50S
NORTH TO THE LOWER AND MIDDLE 60S SOUTH. LIGHT NORTH WINDS ARE ADDING
TO THE CHILL THROUGH MOST OF THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH EAST KENTUCKY STILL IN
THE GRIP OF A BROAD AND UNSEASONABLY DEEP TROUGH THROUGH THE EASTERN
HALF OF THE NATION. FAIRLY FAST NORTHWEST FLOW AT THE BASE OF THIS
TROUGH WILL KEEP A SERIES OF WEAK DISTURBANCES MOVING THROUGH EAST
KENTUCKY DURING THE SHORT TERM PORTION OF THE FORECAST. THE
HEALTHIEST OF THESE ACTUALLY PASSES THROUGH DURING THE DAY WEDNESDAY
WITH A KINK IN THE FLOW LINES. GIVEN THE MODEL SIMILARITIES ALOFT
HAVE GONE WITH A GENERAL BLEND WHILE FAVORING THE HRRR AND NAM12
THROUGH THE FIRST 18 TO 24 HOURS.
SENSIBLE WEATHER WILL FEATURE THE LINGERING SHOWERS AND POCKETS OF
SPRINKLES/DRIZZLE DRYING UP BY EARLY EVENING WITH SOME CLEARING
EXPECTED FOR A TIME. HOWEVER...THIS CLEARING...WITH LITTLE IN THE
WAY OF SFC WINDS...WILL LIKELY ALLOW AREAS OF DENSE FOG AND LOW
STRATUS TO DEVELOP...RESTRICTING VISIBILITY IN MOST PLACES ACROSS
EAST KENTUCKY BY DAWN. HAVE HIT THIS HARD IN THE GRIDS AND ALSO THE
HWO. WILL LEAVE IT TO LATER SHIFTS TO MONITOR THE CLEARING...
ADVECTION...AND PRELIMINARY FOG PRODUCTION FOR A POTENTIAL ADVISORY
OR SPS. ONCE THE FOG BURNS OFF ON WEDNESDAY MORNING SOME SUNSHINE CAN
BE EXPECTED... BUT THE UPPER LEVEL ENERGY WILL LIKELY BRING IN MORE
LOW AND MID LEVEL CLOUDS. IN FACT...CANNOT COMPLETELY RULE OUT SOME
MORE SPRINKLES OR A LIGHT SHOWER AS THIS WAVE MOVES BY ALOFT
WEDNESDAY AFTERNOON. FOR NOW...THOUGH...HAVE KEPT THE POPS JUST BELOW
MENTIONING. THE WAKE OF THIS WILL SET UP ANOTHER NIGHT OF AT LEAST
PARTIAL CLEARING ALONG WITH AREAS OF FOG...LOCALLY DENSE FORMING LATE
AT NIGHT. THIS SHOULD BE THE COLDER OF THE NIGHTS WITH SOME UPPER 40S
POSSIBLE IN THE VALLEYS THROUGH THE NORTHERN HALF OF THE AREA...AND
ELSEWHERE IF THE CLEARING AND FOG ALLOW IT.
AGAIN 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 NUDGE THE LOWS TONIGHT AND ESPECIALLY WEDNESDAY NIGHT FOR RIDGE
AND VALLEY DIFFERENCES. AS FOR POPS...ENDED UP HIGHER THAN MOS IN THE
NEAR TERM AND ALSO FOR LATER WEDNESDAY...OTHERWISE KEPT THE POPS LOW
SIMILAR TO THE GUIDANCE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 PM EDT TUE SEP 16 2014
THURSDAY MORNING STARTS THE EXTENDED PERIOD WITH AN AMPLIFIED UPPER
LEVEL PATTERN. STRONG TROUGHING WILL EXIST ACROSS MUCH OF THE
EASTERN THIRD OF THE CONUS...WHILE HIGH PRESSURE RIDGING REMAINS
PARKED ACROSS THE SOUTHWESTERN STATES. THIS PATTERN WILL REMAIN IN
PLACE THROUGH FRIDAY...BEFORE IT STARTS TO BREAK DOWN AND HEIGHTS
BEGIN TO BUILD ACROSS EASTERN KY INTO THE DAY SATURDAY. N/NW WINDS
WILL USHER IN COLD WINDS DURING THE DAY THURSDAY...WITH HIGHS ONLY
REACHING THE LOW TO MID 70S. THIS WILL NOT
CONTINUE...HOWEVER...AS A SHORTWAVE MOVES TOWARDS THE REGION DURING
THE DAY FRIDAY. AT THE SURFACE...A POTENT COLD FRONT WILL BE MAKING
ITS WAY FROM THE NORTHERN PLAINS TOWARDS KY...WITH SRLY WINDS
PULLING UP WARM AIR OUT AHEAD OF THE FRONT. THIS WILL RESULT IN
INCREASING TEMPERATURES FRIDAY...REACHING MORE SEASONABLE UPPER 70S
AND LOW 80S FOR BOTH FRIDAY AND SATURDAY.
THE FRONT WILL LOSE STRENGTH AS IT MOVES TOWARDS THE EASTERN KY
REGION AS UPPER LEVEL HEIGHTS CONTINUE TO BUILD INTO THE WEEKEND. BY
THE TIME THE SYSTEM REACHES EASTERN KY...THERE WILL BE VERY LITTLE
INSTABILITY LEFT...AS WELL AS VERY LITTLE CONCERN FOR PWAT VALUES.
MODELS ARE STILL SLIGHTLY DIFFERENT ON THE EXACT TIMING AND EXTENT
OF THE PRECIPITATION...SO WILL CONTINUE TO STICK CLOSE TO A MODEL
BLEND. AS SUCH...EXPECT THE PRECIP TO MOVE AHEAD OF THE FRONT AND
INTO EASTERN KY BETWEEN 12 AND 18Z SUNDAY...AND CONTINUE INTO EARLY
AFTERNOON MONDAY. DESPITE LACK OF INSTABILITY...NEIGHBORING OFFICES
CONTINUE TO FAVOR THE FACT THAT THE FRONTAL BOUNDARY LIFT ALONE MAY
BE ENOUGH TO INITIATE SOME THUNDER. AS SUCH...KEPT IN ONLY SLIGHT
MENTION OF THUNDER AS THE LINE MAKES IT THROUGH KY SUNDAY INTO
MONDAY...WITH THE EXCEPTION OF SUNDAY AFTERNOON...WHERE IT SEEMS THE
INCOMING FRONT WILL BRING A BRIEF PERIOD OF HEIGHTENED INSTABILITY
WITH AFTERNOON HEATING...AND THEREFORE CHANCES WERE INCLUDED.
TEMPS WILL COOL SUBSTANTIALLY BEHIND THE FRONTAL PASSAGE BY DURING
THE DAY MONDAY. UPPER LEVEL RIDGING WILL SLOWLY MOVE IN OVERHEAD
INTO THE DAY TUESDAY...WHILE AT THE SURFACE BROAD HIGH PRESSURE
TAKES CONTROL. SURFACE WINDS WILL BECOME MORE NORTHERLY...AS STRONG
W/NW WINDS ALOFT. THIS WILL RESULT IN THE RETURN OF ANOTHER
UNSEASONABLY COOL AIR MASS AND HIGH TEMPERATURES ONLY TOPPING OUT IN
THE LOW TO MID 70S. TEMPS WILL CONTINUE TO DETERIORATE BY THE DAY
TUESDAY...WITH HIGHS IN THE UPPER 60S TO AROUND 70S EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 757 PM EDT TUE SEP 16 2014
SOME IMPROVEMENT TO FLIGHT CONDITIONS THROUGH THE LATE AFTERNOON
HOURS...BUT EXPECT A RETURN TO LIFR CONDITIONS THROUGH THE OVERNIGHT
AS LOW STRATUS AND FOG REDEVELOPS ACROSS THE AREA. STAYED CLOSE TO
MODEL GUIDANCE...BRINGING ALL TAF SITES DOWN INTO MVFR TERRITORY
LATE THIS EVENING AND THEN TO LIFR LEVELS AFTER MIDNIGHT. WE SHOULD
SEE A GRADUAL IMPROVEMENT INTO THE DAY WEDNESDAY. WINDS THROUGH THE
PERIOD WILL BE GENERALLY LIGHT BUT PICK UP SOME...AROUND 5 KTS FROM
THE NORTH....NORTHWEST WEDNESDAY AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
713 PM EDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 713 PM EDT TUE SEP 16 2014
FORECAST IS IN GOOD SHAPE. TWEAKED GRIDS TO HOURLY OBSERVATIONS.
STILL SEEING SOME VERY LIGHT ECHOS ACROSS THE SOUTHEAST. THEREFORE
WILL HOLD OFF ON ANY UPDATE TO THE ZFP FOR A BIT LONGER BEFORE
REMOVING LIGHT SPRINKLE ACTIVITY. REGIONAL SATELLITE IS SHOWING DECENT
AMOUNT OF CLOUD EROSION AS DRY AIR FROM DEVELOPING SUBSIDENCE
INVERSION ALOFT MIXES INTO THE TOP OF THE BOUNDARY LAYER. RELATIVELY
HIGH SFC DEW POINTS REMAIN HOWEVER. CONCERN IS THAT WITH STRONG
SUBSIDENCE AND THEREFORE DRYING TAKING PLACE JUST ABOVE THE BOUNDARY
LAYER...RADIATIVE COOLING WILL BE THE CATALYST FOR LOW STRATUS AND
FOG TO REDEVELOP OVERNIGHT. WILL KEEP A CLOSE EYE ON OBSERVATIONS
THROUGH THE EVENING IN CASE A HEADLINE IS NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 350 PM EDT TUE SEP 16 2014
19Z SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXITING FAR SOUTHEAST
KENTUCKY AS A COOL AND DRY AREA OF HIGH PRESSURE PUSHES DEEPER INTO
THE OHIO VALLEY. BEHIND THIS BOUNDARY...A FEW LIGHT SHOWERS AND
PLENTY OF SPRINKLES/DRIZZLE REMAIN OVER A GOOD PORTION OF THE CWA.
ON SATELLITE...THE LOW CLOUDS ARE BREAKING UP OVER THE SOUTHERN
PORTION OF EAST KENTUCKY WHILE THEY ARE HOLDING TIGHT OVER JKL AND
POINTS NORTH. THE EXTENSIVE CLOUD COVER AND POCKETS OF LIGHT PCPN
KEPT TEMPERATURES WELL BELOW NORMAL FOR THE DAY WITH READINGS
CURRENTLY RANGING FROM A CHILLY 60 DEGREES ALONG AND NORTH OF
INTERSTATE 64 WHILE SOME 70 DEGREE READINGS HAVE SHOWN UP TO THE
SOUTH THANKS TO PARTIAL SUNSHINE. DEWPOINTS VARY FROM THE MID 50S
NORTH TO THE LOWER AND MIDDLE 60S SOUTH. LIGHT NORTH WINDS ARE ADDING
TO THE CHILL THROUGH MOST OF THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH EAST KENTUCKY STILL IN
THE GRIP OF A BROAD AND UNSEASONABLY DEEP TROUGH THROUGH THE EASTERN
HALF OF THE NATION. FAIRLY FAST NORTHWEST FLOW AT THE BASE OF THIS
TROUGH WILL KEEP A SERIES OF WEAK DISTURBANCES MOVING THROUGH EAST
KENTUCKY DURING THE SHORT TERM PORTION OF THE FORECAST. THE
HEALTHIEST OF THESE ACTUALLY PASSES THROUGH DURING THE DAY WEDNESDAY
WITH A KINK IN THE FLOW LINES. GIVEN THE MODEL SIMILARITIES ALOFT
HAVE GONE WITH A GENERAL BLEND WHILE FAVORING THE HRRR AND NAM12
THROUGH THE FIRST 18 TO 24 HOURS.
SENSIBLE WEATHER WILL FEATURE THE LINGERING SHOWERS AND POCKETS OF
SPRINKLES/DRIZZLE DRYING UP BY EARLY EVENING WITH SOME CLEARING
EXPECTED FOR A TIME. HOWEVER...THIS CLEARING...WITH LITTLE IN THE
WAY OF SFC WINDS...WILL LIKELY ALLOW AREAS OF DENSE FOG AND LOW
STRATUS TO DEVELOP...RESTRICTING VISIBILITY IN MOST PLACES ACROSS
EAST KENTUCKY BY DAWN. HAVE HIT THIS HARD IN THE GRIDS AND ALSO THE
HWO. WILL LEAVE IT TO LATER SHIFTS TO MONITOR THE CLEARING...
ADVECTION...AND PRELIMINARY FOG PRODUCTION FOR A POTENTIAL ADVISORY
OR SPS. ONCE THE FOG BURNS OFF ON WEDNESDAY MORNING SOME SUNSHINE CAN
BE EXPECTED... BUT THE UPPER LEVEL ENERGY WILL LIKELY BRING IN MORE
LOW AND MID LEVEL CLOUDS. IN FACT...CANNOT COMPLETELY RULE OUT SOME
MORE SPRINKLES OR A LIGHT SHOWER AS THIS WAVE MOVES BY ALOFT
WEDNESDAY AFTERNOON. FOR NOW...THOUGH...HAVE KEPT THE POPS JUST BELOW
MENTIONING. THE WAKE OF THIS WILL SET UP ANOTHER NIGHT OF AT LEAST
PARTIAL CLEARING ALONG WITH AREAS OF FOG...LOCALLY DENSE FORMING LATE
AT NIGHT. THIS SHOULD BE THE COLDER OF THE NIGHTS WITH SOME UPPER 40S
POSSIBLE IN THE VALLEYS THROUGH THE NORTHERN HALF OF THE AREA...AND
ELSEWHERE IF THE CLEARING AND FOG ALLOW IT.
AGAIN 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 NUDGE THE LOWS TONIGHT AND ESPECIALLY WEDNESDAY NIGHT FOR RIDGE
AND VALLEY DIFFERENCES. AS FOR POPS...ENDED UP HIGHER THAN MOS IN THE
NEAR TERM AND ALSO FOR LATER WEDNESDAY...OTHERWISE KEPT THE POPS LOW
SIMILAR TO THE GUIDANCE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 PM EDT TUE SEP 16 2014
THURSDAY MORNING STARTS THE EXTENDED PERIOD WITH AN AMPLIFIED UPPER
LEVEL PATTERN. STRONG TROUGHING WILL EXIST ACROSS MUCH OF THE
EASTERN THIRD OF THE CONUS...WHILE HIGH PRESSURE RIDGING REMAINS
PARKED ACROSS THE SOUTHWESTERN STATES. THIS PATTERN WILL REMAIN IN
PLACE THROUGH FRIDAY...BEFORE IT STARTS TO BREAK DOWN AND HEIGHTS
BEGIN TO BUILD ACROSS EASTERN KY INTO THE DAY SATURDAY. N/NW WINDS
WILL USHER IN COLD WINDS DURING THE DAY THURSDAY...WITH HIGHS ONLY
REACHING THE LOW TO MID 70S. THIS WILL NOT
CONTINUE...HOWEVER...AS A SHORTWAVE MOVES TOWARDS THE REGION DURING
THE DAY FRIDAY. AT THE SURFACE...A POTENT COLD FRONT WILL BE MAKING
ITS WAY FROM THE NORTHERN PLAINS TOWARDS KY...WITH SRLY WINDS
PULLING UP WARM AIR OUT AHEAD OF THE FRONT. THIS WILL RESULT IN
INCREASING TEMPERATURES FRIDAY...REACHING MORE SEASONABLE UPPER 70S
AND LOW 80S FOR BOTH FRIDAY AND SATURDAY.
THE FRONT WILL LOSE STRENGTH AS IT MOVES TOWARDS THE EASTERN KY
REGION AS UPPER LEVEL HEIGHTS CONTINUE TO BUILD INTO THE WEEKEND. BY
THE TIME THE SYSTEM REACHES EASTERN KY...THERE WILL BE VERY LITTLE
INSTABILITY LEFT...AS WELL AS VERY LITTLE CONCERN FOR PWAT VALUES.
MODELS ARE STILL SLIGHTLY DIFFERENT ON THE EXACT TIMING AND EXTENT
OF THE PRECIPITATION...SO WILL CONTINUE TO STICK CLOSE TO A MODEL
BLEND. AS SUCH...EXPECT THE PRECIP TO MOVE AHEAD OF THE FRONT AND
INTO EASTERN KY BETWEEN 12 AND 18Z SUNDAY...AND CONTINUE INTO EARLY
AFTERNOON MONDAY. DESPITE LACK OF INSTABILITY...NEIGHBORING OFFICES
CONTINUE TO FAVOR THE FACT THAT THE FRONTAL BOUNDARY LIFT ALONE MAY
BE ENOUGH TO INITIATE SOME THUNDER. AS SUCH...KEPT IN ONLY SLIGHT
MENTION OF THUNDER AS THE LINE MAKES IT THROUGH KY SUNDAY INTO
MONDAY...WITH THE EXCEPTION OF SUNDAY AFTERNOON...WHERE IT SEEMS THE
INCOMING FRONT WILL BRING A BRIEF PERIOD OF HEIGHTENED INSTABILITY
WITH AFTERNOON HEATING...AND THEREFORE CHANCES WERE INCLUDED.
TEMPS WILL COOL SUBSTANTIALLY BEHIND THE FRONTAL PASSAGE BY DURING
THE DAY MONDAY. UPPER LEVEL RIDGING WILL SLOWLY MOVE IN OVERHEAD
INTO THE DAY TUESDAY...WHILE AT THE SURFACE BROAD HIGH PRESSURE
TAKES CONTROL. SURFACE WINDS WILL BECOME MORE NORTHERLY...AS STRONG
W/NW WINDS ALOFT. THIS WILL RESULT IN THE RETURN OF ANOTHER
UNSEASONABLY COOL AIRMASS AND HIGH TEMPERATURES ONLY TOPPING OUT IN
THE LOW TO MID 70S. TEMPS WILL CONTINUE TO DETERIORATE BY THE DAY
TUESDAY...WITH HIGHS IN THE UPPER 60S TO AROUND 70S EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 235 PM EDT TUE SEP 16 2014
LIFR AND IFR CONDITIONS CONTINUE TO PLAGUE MANY OF THE TAF SITES EVEN
THIS LATE INTO THE DAY DUE TO LOW CLOUDS...PATCHY FOG...AND
SCATTERED LIGHT SHOWERS. ANY CLEARING LATER THIS AFTERNOON AND
EVENING WILL LIKELY BE FLEETING AS RADIATIONAL COOLING BRING
STRATUS AND DENSE FOG TO MUCH OF EAST KENTUCKY. HAVE BROUGHT ALL THE
SITES DOWN FOR THIS AFTER MIDNIGHT WITH A GRADUAL IMPROVEMENT INTO
THE DAY WEDNESDAY. WINDS THROUGH THE PERIOD WILL BE LIGHT AND
VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
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
721 PM EDT TUE SEP 16 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 409 PM EDT TUE SEP 16 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A RIDGE OVER WRN NAMERICA
AND A TROF OVER ERN NAMERICA. IN THE TROF...ONE SHORTWAVE IS MOVING
E OF JAMES BAY WITH SECOND JUST UPSTREAM IN FAR NRN ONTARIO. NW FLOW
ACROSS CNTRL CANADA IS SENDING THE NEXT SHORTWAVE SE INTO NRN
SASKATCHEWAN/NRN MANITOBA. AT THE SFC...COLD FRONT ASSOCIATED WITH
THE FIRST SHORTWAVE EXTENDS FROM SRN JAMES BAY TO JUST N OF LAKE
SUPERIOR TO FAR SRN MANITOBA. REGIONAL RADAR DISPLAY HAS SHOWN -SHRA
IN THE VCNTY OF THE COLD FRONT WITH PCPN AS FAR S AS NRN LAKE
SUPERIOR. PCPN HAS BEEN WEAKENING/DISSIPATING OVER THE LAST FEW HRS.
OVER UPPER MI...MOSTLY SUNNY SKIES HAVE ALLOWED TEMPS TO RISE TO 60
TO 70 THIS AFTN.
WHILE COLD FRONT TO THE N WILL CONTINUE TO DRIFT S AND THEN STALL
TONIGHT...IT WILL BE THE THIRD IN THE AFORMENTIONED TRIO OF
SHORTWAVES THAT WILL HELP PROPEL IT S THRU THE AREA ON WED. IN
RESPONSE TO THAT THIRD SHORTWAVE AND UNDER THE RIGHT ENTRANCE OF
UPPER JET OVER NRN ONTARIO/QUEBEC...A SUBTLE SFC WAVE IS ALSO
EXPECTED TO DEVELOP ALONG THE COLD FRONT AND TRACK ACROSS SOUTHERN
LAKE SUPERIOR OR UPPER MI VERY LATE TONIGHT THRU WED MORNING. A NICE
CORRESPONDING RIBBON OF LOW-LEVEL FRONTOGENESIS ALSO DEVELOPS.
SO...MODELS LOOK ON TRACK IN GENERATING A BAND OF -SHRA N OF COLD
FRONT AND PATH OF WEAK SFC WAVE TONIGHT/WED. UTILIZED A CONSENSUS OF
MODEL GUIDANCE IN PARTICULAR HIGHER RES MODELS TO CONSTRUCT PCPN
FCST FOR TONIGHT/WED IN ORDER TO MINIMIZE SLIGHT DIFFERENCES NOTED
IN COLD FRONT WHICH AFFECTS PCPN PLACEMENT. BASED ON LOCATION OF THE
STREAK OF FRONTOGENESIS...EXPECT MOST OF THE -SHRA TO PASS JUST N
AND E OF UPPER MI VERY LATE TONIGHT AND WED MORNING. SO...CHC POPS
WERE PAINTED ACROSS THE KEWEENAW AND ERN FCST AREA. OTHERWISE...
NOTHING MORE THAN SCHC POPS WERE USED.
TEMPS WED ARE TRICKY AS THERE WILL BE AN OPPORTUNITY FOR SOME
WARMING BEFORE FROPA. ACROSS THE N...FRONT SHOULD PASS EARLY ENOUGH
TO LIMIT MUCH WARMING. HIGHS OVER THE N SHOULD RANGE FROM THE UPPER
40S ACROSS THE TIP OF THE KEWEENAW TO MID 50S ELSEWHERE. AFTER
FROPA...TEMPS ACROSS THE N WILL LIKELY FALL INTO THE 40S IN THE
AFTN UNDER A BRISK NRLY WIND AND STRATUS DECK FOLLOWING FROPA.
ACROSS THE S...NUDGED HIGH TEMPS UP...TO AS HIGH AS THE UPPER 60S
FAR SCNTRL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM EDT TUE SEP 16 2014
HIGH PRESSURE CURRENTLY OVER THE NORTHWEST TERRITORIES WILL DROP
SOUTHEAST AND OVER EASTERN LAKE SUPERIOR WEDNESDAY NIGHT BEHIND A
COLD FRONT THAT SLIDES ACROSS THE AREA WEDNESDAY. DRY AIR SURGING
IN BEHIND THIS FRONT SHOULD LEAD TO SKIES CLEARING ACROSS THE AREA
AROUND SUNSET AND SET THE U.P. UP FOR ANOTHER COLD NIGHT WITH
INLAND FROST. AS THE PREVIOUS SHIFT MENTIONED...THE FRONT SAGS A
LITTLE FARTHER SOUTH THAN SHOWN 24HRS AGO...WHICH WILL ALLOW MUCH OF
THE INTERIOR U.P. TO EXPERIENCE CLEAR SKIES. WITH PRECIPITABLE WATER
VALUES AROUND 30 PERCENT OF NORMAL AND GENERALLY LIGHT EASTERLY
FLOW...WILL CONTINUE TO HIGHLIGHT LOWS AROUND FREEZING OVER THE
INTERIOR (COLDEST EAST CLOSER TO THE HIGH CENTER). WITH THOSE LOW
TEMP VALUES...WILL CONTINUE TO SHOW AREAS OF FROST OVER MUCH OF THE
ARE AND MAY NEED FREEZE WARNINGS FOR SOME OF THE EASTERN AREAS.
DRY AIR WILL REMAIN IN PLACE FOR THURSDAY AS THE HIGH SHIFTS TO THE
EAST TOWARDS THE NEW ENGLAND STATES. EXPECT A MOSTLY SUNNY SKY OVER
THE AREA...ALTHOUGH SOME CLOUDS COULD IMPINGE ON THE SOUTHWEST CWA
WITH THE INCREASING SOUTH-SOUTHWESTERLY FLOW IN THE AFTERNOON.
HIGHS WILL REMAIN BELOW NORMAL AND IN THE 50S.
BEST CHANCES FOR PRECIPITATION DURING THE LONG TERM PERIOD WILL
COME FRIDAY THROUGH SATURDAY AS A SERIES OF SHORTWAVES DIVE ACROSS
THE AREA AND PUSH AN ASSOCIATED SURFACE TROUGH FROM THE CANADIAN
PRAIRIES AND CENTRAL U.S. EAST THROUGH THE GREAT LAKES REGION ON
SATURDAY. MODELS STILL DIFFERING ON SOME DETAILS (TO BE EXPECTED
WITH THE PHASING OF THREE WAVES JUST BEFORE REACHING THE
AREA)...BUT THE GENERAL IDEA OF BROAD WARM AIR ADVECTION
PRECIPITATION PUSHING EAST ACROSS THE AREA ON FRIDAY (ALONG WITH
BREEZY SOUTHERLY WINDS) AHEAD OF THE SURFACE TROUGH THAT WILL STALL
OVER THE AREA FRIDAY NIGHT AND SATURDAY MORNING BEFORE A MUCH
STRONGER SHORTWAVE DEVELOPS A SURFACE LOW IN THE DAKOTAS AND PUSHES
IT EAST ACROSS THE UPPER GREAT LAKES SATURDAY NIGHT INTO SUNDAY.
ALTHOUGH THE 12Z GEM DOESN/T AGREE WITH THIS IDEA...FEEL THAT IT IS
THE WAY TO TREND THE FORECAST SINCE THE 12Z GFS TRENDED TOWARDS THE
00Z ECMWF AND THE CONSISTENT IDEA IN THE ECMWF ENSEMBLE MEMBERS.
LATE ARRIVING 12Z ECMWF HAS SPED UP THE SYSTEM...WHICH LARGELY
AFFECTS THE SECOND HALF OF THE WEEKEND. WILL CONTINUE TO SHOW HIGH
END CHANCE AND LOW END LIKELY POPS (SHOWERS/THUNDERSTORMS) FOR THIS
PERIOD...ALTHOUGH THERE WILL LIKELY BE A BRIEF REPRIEVE LATE
SATURDAY NIGHT INTO SUNDAY MORNING BEHIND THE COLD FRONT THAT MOVES
THROUGH. THEN...AS COLDER AIR WRAPS SOUTH BEHIND THE LOW SUNDAY INTO
SUNDAY NIGHT...EXPECT ANOTHER PERIOD OF RAIN SHOWERS AND PROBABLY
SOME BREEZY WEST-NORTHWEST WINDS. DETERMINISTIC MODELS AND THEIR
ENSEMBLE MEMBERS CONTINUE TO TREND COOLER WITH 850MB TEMPS ON SUNDAY
INTO SUDNAY NIGHT (ANYWHERE FROM -1C TO 4C)...BUT WITH THE
WESTERN/CENTRAL LAKE SUPERIOR BUOYS ONLY SHOWING WATER TEMPS IN THE
MID 40S (AROUND 7-8C)...NOT SURE THE DELTA-T VALUE WILL BE COLD
ENOUGH FOR ENHANCEMENT. HIGH PRESSURE WILL BUILD IN BEHIND THE LOW
FOR MONDAY AND TUESDAY...LEADING TO MOSTLY CLEAR SKIES AND A TREND
BACK TOWARDS MORE NORMAL TEMPERATURES FOR LATE SEPTEMBER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 721 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW TONIGHT AS LOW LEVELS
REMAIN DRY. COLD FRONT CURRENTLY OVER ONTARIO WILL DROP S INTO
PORTIONS OF NRN UPPER MI TONIGHT BEFORE STALLING AS SUBTLE SFC LOW
PRES DEVELOPS AND TRACKS ESE ALONG FRONT TOWARD THE UPPER GREAT
LAKES. IT IS EXPECTED THAT LOW CLOUDS AND BAND OF RAIN THAT WILL
DEVELOP N OF FRONT WILL PASS JUST N OF KCMX LATE TONIGHT. AS THE
VERY WEAK SFC LOW PASSES WED MORNING...COLD FRONT WILL PUSH
S...BRINGING LOW MVFR CIGS TO ALL TERMINALS. IFR NOT OUT OF THE
QUESTION AT KCMX AND ESPECIALLY KSAW WHICH WILL SEE A MORE DIRECT
UPSLOPE WIND AFTER FROPA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT TUE SEP 16 2014
AHEAD OF AN APPROACHING COLD FRONT FROM THE N...SW WINDS AS HIGH AS
15-25KT THIS EVENING WILL FALL BACK TO GENERALLY 10-20KT TONIGHT AS
THE FRONT STALLS OVER THE AREA. FRONT WILL GET A PUSH S ON WED...AND
NE WINDS BEHIND THE FRONT WILL INCREASE TO 15-25KT FOR AT LEAST A
TIME. OVER FAR WRN LAKE SUPERIOR...COASTAL CONVERGENCE/FUNNELING
WILL PROBABLY RESULT IN WINDS AS HIGH AS 30KT LOCALLY. WINDS WILL
THEN DIMINISH TO UNDER 20KT WED NIGHT/THU AS HIGH PRES SETTLES OVER
NRN ONTARIO IN THE VCNTY OF LAKE SUPERIOR. AS THE HIGH THEN SHIFTS
TOWARD NEW ENGLAND AND A LOW PRES TROF APPROACHES FROM THE W...S
WINDS WILL INCREASE THU NIGHT/FRI. WITH S WINDS A MORE FAVORABLE
DIRECTION FOR STRONGER WINDS OVER ERN LAKE SUPERIOR THAN OVER THE
W...WINDS SHOULD REACH 20-30KT OVER THE ERN LAKE ON FRI. ALTHOUGH
WINDS WILL DIMINISH ON SAT AS THE TROF ARRIVES OVER THE UPPER
LAKES...W TO NW WINDS WILL AGAIN INCREASE TO AS HIGH AS 20-30KT
BEHIND THE TROF SAT NIGHT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS 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 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 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...UPDATED
NWS ST LOUIS MO
856 PM CDT Tue Sep 16 2014
.UPDATE:
Issued at 845 PM CDT Tue Sep 16 2014
Going forecast looks on track this evening. Sky is clear/mostly
clear across the area with just a bit of cloud cover hanging in
across our SE MO counties. Short range guidance continues to show
an increasing amount of low level moisture convergence over
eastern Kansas/western Missouri this evening with convection
breaking out between 06Z-08Z. Models are pretty consistent in
keeping all but perhaps a few showers out of our area through 12Z
with the lion`s share of the precip back over southwest Missouri.
Should see scattered showers and thunderstorms spread into parts
of central and eastern Missouri later Wednesday morning. RAP and
HRRR seem to want to bring some showers into northeast Missouri by
15Z as well...and I may tweak the PoPs up before sending out the
midnight update if the new 00Z NAM and GFS agree.
Carney
&&
.SHORT TERM: (Through Tonight)
Issued at 230 PM CDT Tue Sep 16 2014
A weak s/w will approach the CWA late tonight bringing a chance
for storms to wrn and srn portions of the CWA late tonight.
Otherwise, expect clouds to continue to break up during the
afternoon and into the evening. Clouds are expected to build into
the region from the W tonight ahead of the s/w. Have trended twd
a compromise of guidance for wrn portions of the CWA and twd the
cooler guidance for ern portions. Latest guidance suggests FG will
develop late tonight impacting srn and ern portions of the CWA
where radiational cooling will be greatest.
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 309 PM CDT Tue Sep 16 2014
(Wednesday through Friday)
Main concern continues to be rain chances tomorrow into tomorrow
night over mainly central and southeast Missouri. GFS/NAM/ECMWF are
still in relatively good agreement in dropping a weak shortwave
trough across Missouri during the day tomorrow. Each of these
models shows some weak low level moisture lingering across central
and southeast Missouri into Wednesday night, so will continue a
chance of showers and thunderstorms in this area. This scenario is
depicted pretty well at least through 00Z by the reflectivity on the
NSSL WRF. Thereafter will maintain a dry forecast Thursday and
Friday as a surface ridge moves across the area at the same time a
upper ridge builds in from the west.
Went on the cooler side of guidance for highs the next couple of
days given the easterly surface flow and it matches up better with
mixing down the 900mb temperatures. Likewise followed the cooler
NAM MOS for lows.
(Saturday through next Tuesday)
While there is still some disagreement between the GFS/ECMWF
regarding the speed and depth of a trough that will pass through the
area this weekend, it still appears that the attendant cold front
will move through on Saturday night and early Sunday. Will keep
chances of showers and thunderstorms going Saturday into Sunday.
Will keep Monday and Tuesday dry at this point as we will be on the
back side of the the upper trough, though the latest runs of the GFS
is showing a secondary through dropping down in the northwesterly
flow on Tuesday. This is a new trend that the ECMWF is not
showing. Still expect at or just above normal temperatures ahead of
the front on Saturday before they drop back below normal for early
next week given expected 850mb temperatures in the 6-9C
range.
Britt
&&
.AVIATION: (For the 00z TAFs through 00z Wednesday Evening)
Issued at 541 PM CDT Tue Sep 16 2014
Northwest flow aloft continues through the period with a
reinforcing short wave coming through tonight. High pressure at
the surface shifts east allowing for a weak southerly flow to
develop. Low level jet, about 5000 ft, kicks in pointing at KS/MO
border,thus most models want to develop precipitation overnight in
this area. Looks like rain will stay west of terminals with COU
having the best chance, but chances still low enough to leave out
of the forecast. VCSH may be needed for the next forecast. Models
also want to bring in some MVFR ceilings. Given the pattern is
more mid-Fall like rather than late summer, and with 60 dew points
not that far away, will go with this at COU and STL. Have a few
doubts about this at STL, so will not hit it extremely hard.
Specifics for KSTL: Looks like any rain that develops will stay to
the soutwest of the terminal. Big question is if MVFR ceilings
will arrive. Given the cool pattern, feel it is possible but have
doubts about how extensive the MVFR shield will be. Surface wind
will be weak, so it is up to the low level jet to bring in the
MVFR clouds. Will bring in MVFR ceilings for a while in the
morning, starting around 12z, then raise them about 4 hours
later. Rest of the period should be VFR
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
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 WILMINGTON NC
1056 PM EDT TUE SEP 16 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE LATE TONIGHT. HIGH PRESSURE WILL
EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...QUITE A LINE OF CONVECTION HAS DEVELOPED
OVER THE PAST FEW HOURS EXTENDING FROM THE SOUTH SIDE OF CHARLOTTE
EASTWARD ACROSS ROCKINGHAM...FAYETTEVILLE...AND APPROACHING CLINTON.
SPC MESOANALYSIS INDICATES SURFACE-BASED PARCELS ARE CAPPED...WHICH
MAKES SENSE GIVEN SURFACE TEMPERATURES IN THE LOWER 70S. ELEVATED
CAPE OF 750-1000 J/KG WITH MINIMAL CAPPING IS AVAILABLE WHEN PARCELS
AROUND 950-925 MB ARE CONSIDERED. MID-LEVEL LAPSE RATES ARE RATHER
STEEP AT 6 DEG C/KM. ALTHOUGH CONVECTION HAS MERGED INTO A LINE
EARLIER THERE WERE HINTS OF SUPERCELLULAR CHARACTERISTICS AS A BELT
OF STRONGER MID-LEVEL FLOW ACROSS NORTH-CENTRAL NORTH CAROLINA IS
PRODUCING 0-6 KM BULK SHEAR VALUES NEAR 30 KNOTS.
THE SURFACE COLD FRONT IS LOCATED 50-100 MILES BEHIND THE
CONVECTION...CURRENTLY EXTENDING ACROSS THE NORTHERNMOST ROW OF
COUNTIES IN NORTH CAROLINA. ALTHOUGH PRESSURES ARE CURRENTLY STEADY
ACROSS THE AREA WE ANTICIPATE FALLING PRESSURES TO DEVELOP ALONG THE
COAST AND OFFSHORE SHORTLY AS LOW PRESSURE DEVELOPS. THIS LOW WILL
PULL THE FRONT DOWN LATE TONIGHT AND OFFSHORE BY DAYBREAK.
SINCE THE CONVECTION IS ELEVATED AND BASED WITHIN A UNIFORM 950-900
MB LAYER IT SHOULD RESPOND MORE TO OVERALL SYNOPTIC FORCING THAN TO
ANYTHING GOING ON HERE AT THE SURFACE. THE UPPER DISTURBANCE IS
LOCATED NEAR I-77 NORTH OF CHARLOTTE AND SHOULD MOVE
EAST-NORTHEASTWARD THROUGH THE NIGHT. AS THE STORMS DRIFT SOUTH THEY
WILL MOVE OUT OF THE INFLUENCE OF THE UPPER TROUGH AND SHOULD
WEAKEN. THIS IS SHOWN BY THE 23Z RUN OF THE HRRR...WHICH ALSO
INDICATES THE CONVECTION MAY JUMP WILMINGTON AND
SOUTHPORT...REDEVELOPING OFFSHORE AFTER 2-3 A.M. WITHIN A REGION OF
SURFACE-BASED INSTABILITY OVER THE WARM OCEAN WATER.
NO CHANGES HAVE BEEN MADE TO FORECAST LOWS...STILL ANTICIPATED TO
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEAK LOW PRESSURE ALONG LINGERING FRONT
WILL GET PUSHED FARTHER OFF SHORE AS HIGH PRESSURE BUILDS DOWN
FROM THE NORTHWEST THROUGH MID WEEK. THE EASTERLY FLOW AROUND THE
TOP OF THE LOW WILL COME UP AGAINST W-NW FLOW AS HIGH PRESSURE
BUILDS IN. THIS WILL PRODUCE SOME LOW LEVEL CONVERGENCE THROUGH WED
AND THE LAST BIT OF ENERGY IN THE MID LEVELS WILL ROUND THE BASE
OF THE TROUGH BEFORE IT LIFTS OFF TO THE NORTHEAST. THEREFORE WILL
KEEP SOME CLOUDS AND POPS IN FORECAST ON WED. THE MID TO UPPER
TROUGH RUNNING DOWN THE EAST COAST WILL SHIFT SLOWLY EAST AND WILL
LIFT FARTHER OFF TO THE NORTHEAST WED INTO THURS. AS TROUGH AXIS
CROSSES THE COAST EARLY THURS...A DEEPER N-NW FLOW WILL ESTABLISH
ITSELF OVER THE CAROLINAS WITH CONSIDERABLE DRYING AND SUBSIDENCE
THROUGH THE MID LEVELS. HIGH PRESSURE WILL BUILD IN WITH LIGHT
NORTHERLY WINDS VEERING AROUND TO THE NE THROUGH LATE THURS. PCP
WATER VALUES DROP FROM AROUND 1.5 INCHES WED AFTN DOWN CLOSER TO
AN INCH BY THURS EVE. DEWPOINT TEMPS IN THE MID TO UPPER 60S WED
AFTN WILL DROP INTO THE LOWER 60S THROUGH THURS. OVERALL EXPECT
CONDITIONS TO IMPROVE WITH INCREASING SUNSHINE AND MORE FALL LIKE
WEATHER.
AS AIR MASS TRANSITIONS TO A DRIER MORE SEASONABLE AIR MASS...SO
WILL THE TEMPS. TEMPS OVERNIGHT WED WILL BE WARMER THAN THURS
NIGHT BY A COUPLE OF DEGREES...MID 60S BOTH NIGHTS. TEMPS WILL
REACH INTO THE 80S ON WED BUT ON THURS TEMPS WILL RUN A FEW
DEGREES COOLER EVEN WITH A GREATER AMOUNT OF SUNSHINE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...ON FRIDAY A LARGE AREA OF COOL HIGH PRESSURE
WILL BE SLIDING EAST ACROSS NEW ENGLAND. THIS ANTICYCLONE WILL HAVE
A RIDGE AXIS EXTENDING ALL THE WAY DOWN INTO THE CAROLINAS. FLOW
ALOFT WILL BE VERY WEAK BUT STILL HAVE SOME SENSE OF TROUGHINESS.
MODELS HAVING A HARD TIME TELLING HOW MUCH THIS TROUGHINESS ERODES
THE EASTERN PERIPHERY OF THE SURFACE RIDGE. THE MORE AGGRESSIVE GFS
MANAGES TO FLING MOISTURE ASHORE AND HAS THE SUPPORT OF THE CMC. THE
(00Z) ECMWF DOES THE SAME BUT WITH A MUCH SLOWER SENSE OF TIMING
KEEPING MOST PLACES DRY TIL SUNDAY. WILL SHOW JUST SLIGHT CHANCE
POPS ALONG THE COAST THROUGH THESE DAYS. THE WEDGE APPEARS TO WASH
OUT BY MONDAY AT WHICH TIME RAIN CHANCES SHIFT TO BEING TIED TO A
DEVELOPING PIEDMONT TROUGH AND TEMPS REBOUND TO NORMAL OR HIGHER. A
COLD FRONT APPEARS SLATED FOR A MONDAY NIGHT ARRIVAL.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...RADAR IMAGERY THIS EVENING SHOWS SOME PRE-FRONTAL
CONVECTION APPROACHING FROM THE NORTHWEST. HI-RES GUIDANCE INCLUDING
THE HRRR HOLDS THIS ACTIVITY TOGETHER THROUGH THE EVENING HOURS...SO
WILL INCLUDED VCSH/VCTS FOR KFLO/KLBT EARLY TONIGHT. TEMPO MVFR/IFR
CONDITIONS COULD ACCOMPANY ONE OF THESE STORMS IF IT MOVES DIRECTLY
OVER A TAF SITE...BUT COVERAGE IS LIMITED SO WILL NOT INCLUDE ANY
RESTRICTIONS ATTM.
A PERIOD OF CALM WINDS IS EXPECTED TONIGHT AHEAD OF THE COLD
FRONT...WHICH COULD ALLOW VSBYS TO DROP TO MVFR/TEMPO IFR LEVELS IN
BR. THE GFS/NAM DIFFER IN REGARDS TO THE TIMING OF THE FRONT AND ITS
ASSOCIATED NORTHEASTERLY SURGE. BUT THE MORE REALISTIC GFS SOLUTION
SHOWS NORTHEAST WINDS AROUND 5 KT DEVELOPING BY 09Z WED...WHICH
WOULD HELP MIX THE SFC LAYER AND IMPROVE VSBYS BEFORE DAYBREAK.
THUS...THE FOG POTENTIAL MAY ACTUALLY BE HIGHER EARLIER TONIGHT AS
OPPOSED TO THE NORMALLY FAVORED PRE-DAWN HOURS. THIS LOWERS MY
CONFIDENCE IN DENSE FOG DEVELOPING OVERNIGHT...AND THUS HAVE REMOVED
MENTION OF IFR VSBYS. MVFR CONDITIONS MAY PERSIST THROUGH 12Z WED
BEFORE CIGS GRADUALLY IMPROVE TO VFR BY MIDDAY. NORTHEAST WINDS LESS
THAN 10 KT WILL PREVAIL DURING THE DAY WED.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...WINDS ACROSS THE NC WATERS ARE GENERALLY
FROM THE SOUTH OR SOUTHEAST WITH A MORE VARIABLE PATTERN NOTED
ACROSS THE SOUTH CAROLINA WATERS. PRESSURES SHOULD BEGIN TO FALL
SHORTLY ALONG THE COAST AS LOW PRESSURE DEVELOPS OFFSHORE. THIS LOW
WILL PULL THE COLD FRONT...CURRENTLY ACROSS NORTHERN NORTH
CAROLINA...SOUTHWARD AND OFF THE COAST BY DAYBREAK WITH NORTHERLY
WINDS EXPECTED TO DEVELOP. A LINE OF THUNDERSTORMS ACROSS THE
INTERIOR COASTAL PLAIN WILL PROBABLY WEAKEN BEFORE MAKING IT TO THE
BEACHES...HOWEVER CONDITIONS FAVOR THE DEVELOPMENT OF SCATTERED
THUNDERSTORMS OUT AHEAD OF THIS LINE AFTER MIDNIGHT...MOST LIKELY IN
THE 2-4 AM TIME FRAME. SEAS CURRENTLY 1-2 FT MAY BEGIN TO BUILD
TOWARD 3 FEET ACROSS THE OUTERMOST PORTION OF THE COASTAL WATERS
LATE TONIGHT AS SWELL FROM DISTANT HURRICANE EDOUARD FINALLY MAKES
IT TO THE COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WILL MAINTAIN E-NE WINDS THROUGH MID WEEK
AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH. INITIALLY WINDS WILL
BE LIGHTER AND MORE EASTERLY. THE ON SHORE FLOW UP TO 10 KTS ON
WED WILL COMBINE WITH THE SEA BREEZE AND A LONG PERIOD UP TO 16
SEC EASTERLY SWELL TO PUSH SEAS UP TO 2 TO 4 FT WITH SOME 5 FTERS
IN OUTER WATERS WED AFTN. THE LONGER PERIOD EASTERLY SWELLS FROM
EDOUARD WELL OUT IN THE ATLANTIC WATERS WILL PEAK AROUND 16
SECONDS VERY EARLY WED AND WILL DIMINISH SLOWLY THROUGH THURS.
SEAS WILL ACTUALLY DROP SLIGHTLY THROUGH EARLY THURS BUT A SLIGHT
INCREASE IN NE WINDS UP TO 10-15 KNOTS THROUGH THUR NIGHT SHOULD
PRODUCE ANOTHER SPIKE IN SEAS BY FRI MORNING.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A WEDGE OF HIGH PRESSURE MORE REMINISCENT OF
THE COOL SEASON WILL DEVELOP ON FRIDAY. THE PINCHED NORTHEASTERLY
GRADIENT COULD YIELD A FEW ADVISORY-WORTHY 6 FT SEAS INTO NRN
ZONES...BUT WNA GUIDANCE HAS COME DOWN FROM PREVIOUS RUNS AND IT
MAY BE QUITE MARGINAL. CURRENT FCST STILL SHOWING A RAMP UP TO 4
TO 6 THOUGH. WAVE SHADOWING WILL PRECLUDE ADVISORY OVER SOUTHERN
WATERS. A MODERATE NORTHEASTERLY FLOW WILL REMAIN IN PLACE FOR THE
REST OF THE PERIOD WITH A GRADUAL DECREASE IN STRENGTH. BORDERLINE
SCEC/ADVISORY MAY CONTINUE OVER NRN ZONES INTO SATURDAY. FURTHER
WEAKENING OF THE HIGH PRESSURE WILL BRING QUIETER CONDITIONS COME
SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
734 PM EDT TUE SEP 16 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE LATE TONIGHT. HIGH PRESSURE WILL
EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM TUESDAY...IN THE BATTLE OF MODELS...THE 18Z GFS AND 20Z
HRRR APPEAR TO BE THE BEST SOLUTIONS OVERNIGHT. THE 18Z NAM IN
PARTICULAR HAS PROBLEMS WITH ITS DEEPENING OF THE SURFACE LOW ACROSS
THE SC COASTAL PLAIN RATHER THAN OFFSHORE AS THE BULK OF THE LATEST
MODELS SHOW. THIS FEEDS BACK INTO PROBLEMS WITH THE NAM`S WIND
FORECAST AND ITS CONSIDERABLE COVERAGE OF PRECIPITATION VERY LATE
TONIGHT INLAND. GOING WITH THE GFS/HRRR SOLUTION MEANS THE CURRENT
CONVECTIVE ACTIVITY IN THE NC FOOTHILLS/WESTERN PIEDMONT SHOULD
SLIDE DOWN INTO THE BENNETTSVILLE/LUMBERTON AREA IN THE 9-11 PM
TIMEFRAME. POPS HAVE BEEN INCREASED TO NEAR 50 PERCENT HERE. THE
COLD FRONT CURRENTLY ACROSS THE NC MOUNTAINS AND NEAR THE NC/VA
BORDER WILL BE DRAWN SOUTHWARD OVERNIGHT...PULLED INTO THE ZONE OF
LOWERING PRESSURES ACROSS THE SC OFFSHORE WATERS.
CONVECTIVE ACTIVITY ACROSS FROM MIDNIGHT ONWARD IS LESS
CERTAIN...BUT A WIDESPREAD ZONE OF 20-30 POPS REMAINS IN THE
FORECAST AS RATHER STEEP LAPSE RATES ALOFT DEVELOP WITH THE
APPROACHING UPPER TROUGH AND CONSIDERABLE LOW LEVEL MOISTURE POOLS
NEAR THE FRONT. A 300 MB JET STREAK MAY ALSO BECOME FAVORABLY
ALIGNED AFTER MIDNIGHT...ALTHOUGH IT APPEARS THIS WILL MAINLY BE A
FACTOR FOR OFFSHORE CONVECTION RATHER THAN ACTIVITY ON LAND.
NO CHANGES HAVE BEEN MADE TO TEMPERATURE FORECASTS WITH LOWS FALLING
IN THE UPPER 60S INLAND TO LOWER 70S ON THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEAK LOW PRESSURE ALONG LINGERING FRONT
WILL GET PUSHED FARTHER OFF SHORE AS HIGH PRESSURE BUILDS DOWN
FROM THE NORTHWEST THROUGH MID WEEK. THE EASTERLY FLOW AROUND THE
TOP OF THE LOW WILL COME UP AGAINST W-NW FLOW AS HIGH PRESSURE
BUILDS IN. THIS WILL PRODUCE SOME LOW LEVEL CONVERGENCE THROUGH WED
AND THE LAST BIT OF ENERGY IN THE MID LEVELS WILL ROUND THE BASE
OF THE TROUGH BEFORE IT LIFTS OFF TO THE NORTHEAST. THEREFORE WILL
KEEP SOME CLOUDS AND POPS IN FORECAST ON WED. THE MID TO UPPER
TROUGH RUNNING DOWN THE EAST COAST WILL SHIFT SLOWLY EAST AND WILL
LIFT FARTHER OFF TO THE NORTHEAST WED INTO THURS. AS TROUGH AXIS
CROSSES THE COAST EARLY THURS...A DEEPER N-NW FLOW WILL ESTABLISH
ITSELF OVER THE CAROLINAS WITH CONSIDERABLE DRYING AND SUBSIDENCE
THROUGH THE MID LEVELS. HIGH PRESSURE WILL BUILD IN WITH LIGHT
NORTHERLY WINDS VEERING AROUND TO THE NE THROUGH LATE THURS. PCP
WATER VALUES DROP FROM AROUND 1.5 INCHES WED AFTN DOWN CLOSER TO
AN INCH BY THURS EVE. DEWPOINT TEMPS IN THE MID TO UPPER 60S WED
AFTN WILL DROP INTO THE LOWER 60S THROUGH THURS. OVERALL EXPECT
CONDITIONS TO IMPROVE WITH INCREASING SUNSHINE AND MORE FALL LIKE
WEATHER.
AS AIR MASS TRANSITIONS TO A DRIER MORE SEASONABLE AIR MASS...SO
WILL THE TEMPS. TEMPS OVERNIGHT WED WILL BE WARMER THAN THURS
NIGHT BY A COUPLE OF DEGREES...MID 60S BOTH NIGHTS. TEMPS WILL
REACH INTO THE 80S ON WED BUT ON THURS TEMPS WILL RUN A FEW
DEGREES COOLER EVEN WITH A GREATER AMOUNT OF SUNSHINE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...ON FRIDAY A LARGE AREA OF COOL HIGH PRESSURE
WILL BE SLIDING EAST ACROSS NEW ENGLAND. THIS ANTICYCLONE WILL HAVE
A RIDGE AXIS EXTENDING ALL THE WAY DOWN INTO THE CAROLINAS. FLOW
ALOFT WILL BE VERY WEAK BUT STILL HAVE SOME SENSE OF TROUGHINESS.
MODELS HAVING A HARD TIME TELLING HOW MUCH THIS TROUGHINESS ERODES
THE EASTERN PERIPHERY OF THE SURFACE RIDGE. THE MORE AGGRESSIVE GFS
MANAGES TO FLING MOISTURE ASHORE AND HAS THE SUPPORT OF THE CMC. THE
(00Z) ECMWF DOES THE SAME BUT WITH A MUCH SLOWER SENSE OF TIMING
KEEPING MOST PLACES DRY TIL SUNDAY. WILL SHOW JUST SLIGHT CHANCE
POPS ALONG THE COAST THROUGH THESE DAYS. THE WEDGE APPEARS TO WASH
OUT BY MONDAY AT WHICH TIME RAIN CHANCES SHIFT TO BEING TIED TO A
DEVELOPING PIEDMONT TROUGH AND TEMPS REBOUND TO NORMAL OR HIGHER. A
COLD FRONT APPEARS SLATED FOR A MONDAY NIGHT ARRIVAL.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...RADAR IMAGERY THIS EVENING SHOWS SOME PRE-FRONTAL
CONVECTION APPROACHING FROM THE NORTHWEST. HI-RES GUIDANCE INCLUDING
THE HRRR HOLDS THIS ACTIVITY TOGETHER THROUGH THE EVENING HOURS...SO
WILL INCLUDED VCSH/VCTS FOR KFLO/KLBT EARLY TONIGHT. TEMPO MVFR/IFR
CONDITIONS COULD ACCOMPANY ONE OF THESE STORMS IF IT MOVES DIRECTLY
OVER A TAF SITE...BUT COVERAGE IS LIMITED SO WILL NOT INCLUDE ANY
RESTRICTIONS ATTM.
A PERIOD OF CALM WINDS IS EXPECTED TONIGHT AHEAD OF THE COLD
FRONT...WHICH COULD ALLOW VSBYS TO DROP TO MVFR/TEMPO IFR LEVELS IN
BR. THE GFS/NAM DIFFER IN REGARDS TO THE TIMING OF THE FRONT AND ITS
ASSOCIATED NORTHEASTERLY SURGE. BUT THE MORE REALISTIC GFS SOLUTION
SHOWS NORTHEAST WINDS AROUND 5 KT DEVELOPING BY 09Z WED...WHICH
WOULD HELP MIX THE SFC LAYER AND IMPROVE VSBYS BEFORE DAYBREAK.
THUS...THE FOG POTENTIAL MAY ACTUALLY BE HIGHER EARLIER TONIGHT AS
OPPOSED TO THE NORMALLY FAVORED PRE-DAWN HOURS. THIS LOWERS MY
CONFIDENCE IN DENSE FOG DEVELOPING OVERNIGHT...AND THUS HAVE REMOVED
MENTION OF IFR VSBYS. MVFR CONDITIONS MAY PERSIST THROUGH 12Z WED
BEFORE CIGS GRADUALLY IMPROVE TO VFR BY MIDDAY. NORTHEAST WINDS LESS
THAN 10 KT WILL PREVAIL DURING THE DAY WED.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM TUESDAY...LIGHT GENERALLY ONSHORE WINDS WILL BACK
AROUND TO THE NORTHEAST OVERNIGHT AS PRESSURES FALL OFF THE SOUTH
CAROLINA COAST IN ASSOCIATION WITH LOW PRESSURE DEVELOPING OFFSHORE.
A COLD FRONT CURRENTLY ACROSS THE NC MOUNTAINS AND ALONG THE NC/VA
BORDER WILL ALSO BE PULLED THROUGH THE AREA LATE...WITH THE
STRONGEST WINDS (10-15 KNOTS) DEVELOPING AROUND DAYBREAK. SHOWER
ACTIVITY NEAR GEORGETOWN/WINYAH BAY SHOULD DIMINISH OVER THE NEXT
COUPLE HOURS BUT ADDITIONAL SCATTERED SHOWERS AND T-STORMS MAY POP UP
AHEAD OF AND NEAR THE FRONT OVERNIGHT.
BASED ON CURRENT BUOY OBSERVATIONS SEAS HAVE BEEN ADJUSTED DOWNWARD
TO 1-2 FEET CURRENTLY. THE LOCAL SWAN WAVE MODEL IS OFTEN TOO
AGGRESSIVE BUILDING SEAS WITH LONG PERIOD SWELLS...AND SEA HEIGHT
FORECASTS HAVE BEEN ADJUSTED DOWNWARD TO NEAR THE NOAA WAVEWATCH
GUIDANCE OVERNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WILL MAINTAIN E-NE WINDS THROUGH MID WEEK
AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH. INITIALLY WINDS WILL
BE LIGHTER AND MORE EASTERLY. THE ON SHORE FLOW UP TO 10 KTS ON
WED WILL COMBINE WITH THE SEA BREEZE AND A LONG PERIOD UP TO 16
SEC EASTERLY SWELL TO PUSH SEAS UP TO 2 TO 4 FT WITH SOME 5 FTERS
IN OUTER WATERS WED AFTN. THE LONGER PERIOD EASTERLY SWELLS FROM
EDOUARD WELL OUT IN THE ATLANTIC WATERS WILL PEAK AROUND 16
SECONDS VERY EARLY WED AND WILL DIMINISH SLOWLY THROUGH THURS.
SEAS WILL ACTUALLY DROP SLIGHTLY THROUGH EARLY THURS BUT A SLIGHT
INCREASE IN NE WINDS UP TO 10-15 KNOTS THROUGH THUR NIGHT SHOULD
PRODUCE ANOTHER SPIKE IN SEAS BY FRI MORNING.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A WEDGE OF HIGH PRESSURE MORE REMINISCENT OF
THE COOL SEASON WILL DEVELOP ON FRIDAY. THE PINCHED NORTHEASTERLY
GRADIENT COULD YIELD A FEW ADVISORY-WORTHY 6 FT SEAS INTO NRN
ZONES...BUT WNA GUIDANCE HAS COME DOWN FROM PREVIOUS RUNS AND IT
MAY BE QUITE MARGINAL. CURRENT FCST STILL SHOWING A RAMP UP TO 4
TO 6 THOUGH. WAVE SHADOWING WILL PRECLUDE ADVISORY OVER SOUTHERN
WATERS. A MODERATE NORTHEASTERLY FLOW WILL REMAIN IN PLACE FOR THE
REST OF THE PERIOD WITH A GRADUAL DECREASE IN STRENGTH. BORDERLINE
SCEC/ADVISORY MAY CONTINUE OVER NRN ZONES INTO SATURDAY. FURTHER
WEAKENING OF THE HIGH PRESSURE WILL BRING QUIETER CONDITIONS COME
SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...MBB
AVIATION...BJR
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 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 SAN ANGELO TX
1103 PM CDT TUE SEP 16 2014
.AVIATION...
/06Z TAFS/
A few showers continue across parts of the area this evening, but
coverage should remain limited enough to not mention in the current
TAFs. Uncertainty remains in just how much stratus development we
will see during the early morning hours. Mid and upper level cloud
cover may serve to hinder the extent of the stratus. For now, the
current TAF forecast indicates MVFR ceilings at KSOA, KBBD, and KJCT
between 09z and 11z, with VFR ceilings returning by mid morning
Wednesday. Confidence in timing of any showers and thunderstorms
that develop across the area Wednesday afternoon remains low, so any
mention of thunder was left out of the current TAF package. Winds
will remain light through the next 24 hours.
&&
.PREV DISCUSSION... /ISSUED 913 PM CDT TUE SEP 16 2014/
UPDATE...
Scattered showers, and a few thunderstorms, will continue this
evening. Most of this activity will be focused on the I-10
corridor, but has shown some northward propagation over the past
hour or so. Farther north, convection continue to weaken as it
moves into the Big Country, but light rainfall amounts are
anticipated during the overnight period. Chance PoPs were retained
tonight, raised to 40% across the southern counties where
convection is more widespread. RAP Mesoanalysis MUCAPE values
remain around 1000 J/kg across the south, so thunder was retained
south of a San Angelo to San Saba line. Only minor adjustments
were made to the wind/temp/dewpoint grids.
Johnson
PREV DISCUSSION... /ISSUED 614 PM CDT TUE SEP 16 2014/
AVIATION...
/00Z TAFS/
Scattered showers this evening, will gradually decrease in
coverage shortly after 00z. Isolated showers will be possible
overnight, but coverage should remain limited enough to preclude a
mention in the current TAF package. Stratus development is
forecast between 11z and 12z at KSOA, KBBD, and KJCT, resulting in
MVFR ceilings. VFR conditions will return to all sites by about
15z. Scattered showers and thunderstorms will once again be
possible Wednesday afternoon, but confidence is not high enough to
include a mention in the TAF package. Winds will remain light
through the next 24 hours.
PREV DISCUSSION... /ISSUED 345 PM CDT Tue SEP 16 2014/
SHORT TERM...
(Tonight and Wednesday)
As of 3 PM...isolated to scattered showers have developed across
the area in an uncapped and weakly unstable airmass. Most of
this activity will diminish with the loss of heating after sunset
this evening. Tropical moisture will remain in place across West
Texas tonight through Wednesday as the remnants of Odile continue
to spread east across the area. Much like the past couple of
nights, a few showers will be possible during the overnight period
and will keep the inherited slight POPs intact.
Scattered showers and thunderstorms are expected again on
Wednesday as embedded disturbances from the remnants of Odile
move across the area. Precipitable water values will remain high
(around 2 inches) and steering flow rather weak, so locally heavy
rainfall will be a concern with the strongest convection. Low
temperatures tonight will be around 70 degrees, with highs on
Wednesday in the mid and upper 80s
LONG TERM...
(Wednesday night into Tuesday)
Remnants of Odile are expected to move northeast into the Texas
Panhandle Friday and Oklahoma Friday night/Saturday. Both the
GFS and EC develop several bands of showers eastward into West
Central Texas during this period. With a tropical atmosphere in
place and precipitable water amounts approaching 2 inches,
potential exists for locally heavy rainfall in bands that develop,
particularly during afternoon hours. Low level focus for
convection will be lacking, but a few areas could pick up 1 to 3
inches in slow moving storms.
A cold front moves through Sunday. Again, locally heavy
rainfall/localized flooding will be possible in tropical like
atmosphere. Computers solutions have slowed down front as it moves
into West Central Texas, with both the GFS and EC models
indicating rainfall continuing into Monday and Tuesday next week.
Will not put in rain chances in for Monday and Tuesday, but later
shifts will need to reevaluate.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 70 86 69 83 69 / 30 40 50 50 40
San Angelo 70 86 71 86 71 / 30 40 50 50 30
Junction 72 85 72 86 72 / 40 40 50 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Daniels
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
913 PM CDT TUE SEP 16 2014
.UPDATE...
Scattered showers, and a few thunderstorms, will continue this
evening. Most of this activity will be focused on the I-10
corridor, but has shown some northward propagation over the past
hour or so. Farther north, convection continue to weaken as it
moves into the Big Country, but light rainfall amounts are
anticipated during the overnight period. Chance PoPs were retained
tonight, raised to 40% across the southern counties where
convection is more widespread. RAP Mesoanalysis MUCAPE values
remain around 1000 J/kg across the south, so thunder was retained
south of a San Angelo to San Saba line. Only minor adjustments
were made to the wind/temp/dewpoint grids.
Johnson
&&
.PREV DISCUSSION... /ISSUED 614 PM CDT TUE SEP 16 2014/
AVIATION...
/00Z TAFS/
Scattered showers this evening, will gradually decrease in
coverage shortly after 00z. Isolated showers will be possible
overnight, but coverage should remain limited enough to preclude a
mention in the current TAF package. Stratus development is
forecast between 11z and 12z at KSOA, KBBD, and KJCT, resulting in
MVFR ceilings. VFR conditions will return to all sites by about
15z. Scattered showers and thunderstorms will once again be
possible Wednesday afternoon, but confidence is not high enough to
include a mention in the TAF package. Winds will remain light
through the next 24 hours.
PREV DISCUSSION... /ISSUED 345 PM CDT Tue SEP 16 2014/
SHORT TERM...
(Tonight and Wednesday)
As of 3 PM...isolated to scattered showers have developed across
the area in an uncapped and weakly unstable airmass. Most of
this activity will diminish with the loss of heating after sunset
this evening. Tropical moisture will remain in place across West
Texas tonight through Wednesday as the remnants of Odile continue
to spread east across the area. Much like the past couple of
nights, a few showers will be possible during the overnight period
and will keep the inherited slight POPs intact.
Scattered showers and thunderstorms are expected again on
Wednesday as embedded disturbances from the remnants of Odile
move across the area. Precipitable water values will remain high
(around 2 inches) and steering flow rather weak, so locally heavy
rainfall will be a concern with the strongest convection. Low
temperatures tonight will be around 70 degrees, with highs on
Wednesday in the mid and upper 80s
LONG TERM...
(Wednesday night into Tuesday)
Remnants of Odile are expected to move northeast into the Texas
Panhandle Friday and Oklahoma Friday night/Saturday. Both the
GFS and EC develop several bands of showers eastward into West
Central Texas during this period. With a tropical atmosphere in
place and precipitable water amounts approaching 2 inches,
potential exists for locally heavy rainfall in bands that develop,
particularly during afternoon hours. Low level focus for
convection will be lacking, but a few areas could pick up 1 to 3
inches in slow moving storms.
A cold front moves through Sunday. Again, locally heavy
rainfall/localized flooding will be possible in tropical like
atmosphere. Computers solutions have slowed down front as it moves
into West Central Texas, with both the GFS and EC models
indicating rainfall continuing into Monday and Tuesday next week.
Will not put in rain chances in for Monday and Tuesday, but later
shifts will need to reevaluate.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 70 86 69 83 69 / 30 40 50 50 40
San Angelo 70 86 71 86 71 / 30 40 50 50 30
Junction 72 85 72 86 72 / 40 40 50 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS PORTLAND OR
832 PM PDT TUE SEP 16 2014
.SYNOPSIS...A LOW PRESSURE SYSTEM CURRENTLY WELL OFF THE OREGON COAST
WILL MOVE TOWARDS SOUTHERN OREGON AND BRING A CHANCE OF SHOWERS LATE
WEDNESDAY INTO THURSDAY ACROSS NORTHWEST OREGON AND SOUTHWEST
WASHINGTON. ONSHORE FLOW WILL KEEP MOST OF THE SMOKE FROM THE 36
PIT AND DECEPTION COMPLEX FIRES OVER THE CASCADES AND POINTS EAST.
HOWEVER...HIGH PRESSURE AND OFFSHORE FLOW LOOKS INCREASINGLY LIKELY
TO BUILD OVER THE REGION TOWARDS THE WEEKEND SO EXPECT SMOKEY
CONDITIONS AND TEMPERATURES POSSIBLY APPROACHING 90F AGAIN ACROSS THE
WILLAMETTE VALLEY.
&&
.SHORT TERM...UPPER LEVEL MOISTURE ASSOCIATED WITH A LARGE SHORTWAVE
TROUGH WILL CONTINUE TO LIFT NORTH TONIGHT...ALREADY SEEING SOME
ECHOES ON RADAR IMAGERY THIS EVENING BUT ITS STILL MOST LIKELY VIRGA.
MODELS CONTINUE TO SHOW THE BEST THREAT FOR ANY MEASURABLE
PRECIPITATION HITTING THE SW WASHINGTON AND NW OREGON COAST...BUT IT
LOOKS LIKE IT MAY REACH THE COAST EARLY WEDNESDAY MORNING. WILL ALSO
SEE PATCHY LOW STRATUS ALONG THE COAST OVERNIGHT...PARTICULARLY ALONG
THE CENTRAL COAST NEAR NEWPORT. OTHERWISE JUST EXPECT INCREASING MID
LEVEL CLOUDS INTO EARLY WEDNESDAY MORNING AS THE SURFACE LOW SPREADS
MOISTURE NORTHWARD. /27
THE 36 PIT AND DECEPTION COMPLEX FIRES CONTINUE TO PRODUCE PLENTY OF
SMOKE. CONTINUE TO CHECK WITH YOUR STATE AIR QUALITY AGENCY FOR THE
LATEST AIR QUALITY OBSERVATIONS. EXPECT VALLEY LOCATIONS IMMEDIATELY
DOWN RIVER OF THESE FIRES LIKE ESTACADA AND OAKRIDGE TO EXPERIENCE
PROBLEMS WITH SMOKE EACH NIGHT AND EARLY MORNING THIS WEEK.
FORTUNATELY...WEST WINDS EACH AFTERNOON AND EVENING SHOULD DISPERSE
SMOKE...ESPECIALLY WHEN THE FIRES ARE GENERALLY MOST ACTIVE....TO THE
EAST.
FOR WEDNESDAY...MODELS AGREE THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE CURRENTLY WELL OFF THE CALIFORNIA COAST WILL SHIFT
NORTHEASTWARD TOWARDS THE CALIFORNIA/OREGON STATE LINE THROUGH
WEDNESDAY EVENING...BEFORE SPLITTING AND NOSE DIVING INTO SOUTHERN
CALIFORNIA LATE THURSDAY. THIS RATHER MESSY PATTERN WILL RESULT IN
WAVES OF MAINLY MID TO UPPER LEVEL CLOUDS SPREADING ACROSS THE AREA
THROUGH WEDNESDAY EVENING. ASIDE FROM A FEW SPRINKLES FROM TIME TO
TIME...SUSPECT MOST LOCATIONS WILL REMAIN DRY BASED ON MODEL
SOUNDINGS. KEPT A SLIGHT CHANCE MENTION OF THUNDER ACROSS OUR
SOUTHEASTERN ZONES WEDNESDAY AFTERNOON AND EVENING WHERE PERHAPS
ENOUGH MID LEVEL INSTABILITY COULD GENERATE A LIGHTNING STRIKE OR
TWO...BUT CONFIDENCE IN THIS SCENARIO PANNING OUT IS VERY LOW.
FOR THURSDAY...THE NAM AND GFS SUGGEST A LOW LEVEL SURGE OF
ISENTROPIC LIFT AHEAD OF THE TROUGH AXIS LATE WEDNESDAY NIGHT INTO
THURSDAY MORNING MAY SATURATE THE ATMOSPHERIC COLUMN AND RESULT IN
LIGHT PRECIPITATION ACROSS MUCH OF THE AREA THURSDAY MORNING. LOW
LEVEL WESTERLY FLOW SHOULD ALSO AID IN WRINGING OUT LIGHT RAIN
ACROSS THE OROGRAPHICALLY FAVORABLE COAST RANGE AND CASCADES. AS A
RESULT...POPS WERE NUDGED UPWARDS DURING THIS PERIOD INTO THE LOW
END LIKELY CATEGORY ALONG THE COAST AND ACROSS THE TOPOGRAPHY...AND
HIGH END CHANCE CATEGORY FOR VALLEY LOCATIONS. MODELS SUGGEST CLOUD
COVER WILL BE AMPLE ON THURSDAY...BUT IF WE DO GET ANY BREAKS IN THE
CLOUDS...IT WILL NOT TAKE MUCH HEATING TO PRODUCE THUNDERSTORMS. AT
THIS POINT...CLOUD COVER LOOKS PRETTY SOLID THURSDAY SO LEFT THE
MENTION OF THUNDER OUT OF THE FORECAST...BUT THIS WILL BE WORTH
MONITORING OVER THE NEXT 48 HOURS.
OVERALL...CONTINUE TO REMAIN NERVOUS THAT MODELS ARE TOO AGGRESSIVE
WITH THE MOISTURE AND PRECIPITATION CHANCES LATE WEDNESDAY INTO
THURSDAY GIVEN THE SPLITTING NATURE OF THE UPPER LEVEL TROUGH. IN
ADDITION...THIS WILL BE THE FIRST FALL LIKE STORM SYSTEM TO TRY AND
BREAK DOWN THE LONGWAVE RIDGE...WHICH ALSO DOES NOT BODE WELL.
FOR FRIDAY...SHORTWAVE RIDGING MOVING INTO THE AREA LATE THURSDAY
INTO FRIDAY SHOULD ALLOW THE AREA TO DRY OUT CONSIDERABLY.
STRENGTHENING THERMAL LOW PRESSURE OVER CALIFORNIA ON FRIDAY WILL
TURN WINDS MORE NORTHERLY...AND THE AREA WILL BEGIN ANOTHER WARMING
TREND. /NEUMAN
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY
THROUGH TUESDAY...GFS...DGEX...AND ECMWF ALL SHOW A RETURN TO
EASTERLY FLOW ON SATURDAY WHICH WILL WARM TEMPERATURES ACROSS THE
AREA. THIS WARM UP WILL ONLY LAST THROUGH SUNDAY...AS WINDS SHIFT
BACK TO THE WEST FROM AN UPPER-LEVEL TROUGH AND ASSOCIATED CYCLONE
DEEPENING OVER THE GULF OF ALASKA. THIS WILL COOL TEMPERATURES AND
BRING THE MARINE LAYER BACK IN AT NIGHT MONDAY AND TUESDAY. -MCCOY
&&
.AVIATION...RATHER TRANQUIL WITH LIGHT WINDS AND VARIABLE MID AND
HIGH CLOUDS. ONSHORE GRADIENT IS QUITE LIGHT...SO NOT EXPECTING
ANY FOG OR LOW CLOUDS...THOUGH CAN NOT COMPLETELY ELIMINATE A FEW
PATCHES OF FOG IN BAYS AND COAST RANGE VALLEYS TONIGHT. WILL SEE
INCREASING MID LEVEL CLOUDS ON WED...ALONG WITH A SHOWER OR TWO.
SMOKE FROM THE 36-PIT FIRE CONTINUES TO DRIFT TO THE E AND NE.
WILL SEE SMOKE CONTINUE IN FAR EAST COLUMBIA GORGE...UPPER HOOD
RIVER VALLEY AND AROUND MT HOOD...WITH SOME SMOKE TRAPPED SETTLING
IN VALLEYS TO E AND N OF THE FIRE. WITH S WINDS ALOFT OVER NEXT
FEW DAYS...SMOKE FROM FIRES OVER SW OREGON AND NW CALIF WILL DRIFT
N TO NE...AFFECTING SLANTWISE VISIBILITY FROM CASCADES EASTWARD.
KPDX AND APPROACHES...VFR WITH VARIABLE HIGH CLOUDS TONIGHT...AND
INCREASING MID LEVEL CLOUDS ON WED. ROCKEY.
&&
.MARINE...FAIRLY BENIGN CONDITIONS PERSIST OVER THE WATERS FOR
THE NEXT FEW DAYS AS WEAK LOW PRES WILL MAINTAIN S TO SE WIND
LESS THAN 15 KT. THERE WILL BE A MIX OF WAVE TRAINS WITH VARYING
PERIODS...PREDOMINATELY FROM THE W AT AROUND 15 SEC. OVERALL SEAS
RUNNING 5 TO 7 FT...WITH HIGHEST FURTHER OFFSHORE.
HIGH PRES WILL REBUILD OVER THE WATERS FRI AND SAT...WITH THERMAL
LOW PRES OVER THE COAST AND COASTAL WATERS. THIS WILL BRING
ANOTHER ROUND OF E TO NE WINDS TO THE WATERS THIS WEEKEND WITH
WINDS POSSIBLY GUSTING TO 25 KT ON SAT AND SAT NIGHT. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA AS THE FORECAST AREA.
[top]
Area Forecast Discussion
National Weather Service Spokane WA
831 PM PDT TUE SEP 16 2014
.SYNOPSIS...
The region will remain in a mild southwest flow through Wednesday,
with slight shower chances coming toward the Cascades and northern
mountains. Cooler, more seasonal temperatures follow the passage
of a weak cold front Thursday. Thursday will also be locally
breezy with a chance for light rain showers. More sunshine and
lighter winds return on Friday, with warmer temperatures this
weekend.
&&
.DISCUSSION...
Evening update: watching some of the energy coming up through
Oregon and along the Pacific Northwest coast. Thicker clouds and
some radar returns showing up southwest of Portland and off the
Washington coast. Newest model runs, including the HRRR and the
Hi-res NAM, show some of this moisture sliding up north toward
the Cascades overnight into Wednesday morning. As such I added a
slight chance of showers toward the Cascades for after midnight,
mainly south of Lake Chelan, with the chances expanding northward
toward Canadian border by morning. Some sprinkles are possible
toward the lower elevations including the Wenatchee area,
Waterville Plateau and Okanogan Valley toward the Okanogan
Highlands as well. Otherwise I increased sky cover slightly.
Overnight lows and tomorrow afternoon`s highs generally look on
track. /J. Cote`
&&
.AVIATION...
00Z TAFS: High pressure shifts east and the southwest flow brings
moisture and energy up from the south. Look for some middle and
high clouds, thickening especially Wednesday. A slight chance of
showers comes toward the Cascades...mainly after 12-18Z. Some
smoke from nearby wildfires may also lower VIS toward MVFR
conditions, mainly around PUW and LWS Wednesday morning. Otherwise
look for VFR, dry conditions. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 57 84 58 79 56 75 / 0 10 10 20 10 10
Coeur d`Alene 53 84 54 79 55 74 / 10 10 10 30 30 10
Pullman 54 86 54 80 54 75 / 10 10 10 20 10 10
Lewiston 60 90 62 84 59 80 / 10 10 0 20 20 10
Colville 51 85 53 81 51 78 / 0 10 20 30 20 10
Sandpoint 47 79 49 75 52 71 / 10 10 10 30 30 20
Kellogg 55 82 54 75 52 69 / 10 10 10 30 30 20
Moses Lake 56 87 59 83 56 82 / 0 10 10 10 10 10
Wenatchee 60 86 63 81 61 81 / 10 10 20 20 10 0
Omak 54 88 59 81 55 80 / 0 10 20 30 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
636 PM CDT TUE SEP 16 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 228 PM CDT TUE SEP 16 2014
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING AGAIN OVER WESTERN NORTH AMERICA WHILE TROUGHING
DOMINATES EASTERN CANADA INTO THE GREAT LAKES AND OHIO VALLEY. THIS
PLACES THE FORECAST AREA IN A SUBSIDENT NORTHWEST FLOW REGIME...
FAVORING DRY CONDITIONS AND HIGH PRESSURE AT THE SURFACE. LATEST
SURFACE ANALYSIS SHOWED THE HIGH CENTERED OVER ILLINOIS WITH A RIDGE
AXIS EXTENDING INTO WESTERN WI. AIRMASS OVER THE AREA HAS WARMED
SLIGHTLY FROM YESTERDAY WITH 925MB TEMPS UP TO 10C. HOWEVER...MORE
SUNSHINE AND A DRIER AIRMASS REFLECTED BY PRECIPITABLE WATER VALUES
OF 0.3-0.5 INCHES PER PRECIPITABLE WATER IMAGERY HAS ALLOWED
TEMPERATURES TO CLIMB INTO THE 60S.
THE SHORT TERM PERIOD AGAIN LOOKS QUIET...RESULTING FROM PLENTIFUL
DRY AIR IN PLACE OVER THE NEXT 24 HOURS TO PREVENT PRECIPITATION.
HOWEVER...THERE ARE A FEW ISSUES TO CONTEND WITH...
1. POTENTIAL FOR VALLEY FOG TONIGHT. THE RIDGE AXIS EXTENDING FROM
THE SURFACE HIGH IN ILLINOIS INTO WESTERN WI IS PROGGED TO STAY IN
PLACE THROUGH WEDNESDAY MORNING. WITH DRY AIR IN PLACE...LIGHT WINDS
AND CURRENTLY CLEAR SKIES...TEMPERATURES SHOULD DROP QUICKLY.
HOWEVER...THERE ARE 3 PROBLEMS FOR VALLEY FOG. THE FIRST IS THAT THE
AIR IS MUCH DRIER TODAY COMPARED TO YESTERDAY AT THIS TIME...AND ALL
RAIN FROM YESTERDAY HAS BEEN ABSORBED. SECOND...THE GFS...NAM AND
RAP HAVE ALL TRENDED STRONGER WITH THE WIND FIELD AFTER MIDNIGHT...
WITH POTENTIAL OF UP TO 20 KT SUGGESTED RIGHT ABOVE THE SURFACE.
THESE WINDS COULD REALLY HAMPER FOG AND EVEN STRATUS TRYING TO STICK
AROUND IN THE MISSISSIPPI VALLEY. THIRD...A NEW DISCOVERY TODAY IS
THAT BOTH THE GFS AND NAM SHOW A BAND OF MID CLOUDS MOVING INTO THE
WESTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. THESE CLOUDS MATCH
UP VERY WELL WITH ISENTROPIC LIFT SEEN ON THE 300K SURFACE...WHICH
COULD ALSO HAMPER FOG AND STRATUS FROM STICKING AROUND...EVEN IN THE
TRIBS. THUS...HAVE BACKED DOWN THE COVERAGE OF VALLEY FOG AND
STRATUS OVERNIGHT INTO WEDNESDAY MORNING.
2. TEMPS AND FROST POTENTIAL TONIGHT. RELATED TO THE VALLEY FOG
DISCUSSION ABOVE... READINGS IN CENTRAL WISCONSIN LOOK TO PLUMMET
AGAIN. FOLLOWED PREVIOUS FORECAST IN DROPPING TEMPERATURES TOWARDS
THE MID 30S. THEY SHOULD STAY HIGH ENOUGH TO PRECLUDE FROST
FORMATION...THOUGH. ALONG/WEST OF THE RIVER...INCREASING WIND AND
INCOMING CLOUDS RESULT IN WARMER READINGS.
3. BACKDOOR COLD FRONT WEDNESDAY AFTERNOON. THIS FRONT HAS BEEN
SHOWN FOR MANY DAYS TO COME INTO THE REGION FROM THE NORTH. DRY AIR
WILL PREVENT PRECIPITATION...HOWEVER...THE FRONT SHOULD PULL SOME
WARMER AIR IN AHEAD OF IT TO ALLOW FOR HIGHS TO BE ABOUT 5 DEGREES
WARM THAN TODAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 228 PM CDT TUE SEP 16 2014
QUIET WEATHER CONTINUES FOR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
AS A CANADIAN HIGH DROPS DOWN INTO THE GREAT LAKES REGION BEHIND THE
BACKDOOR COLD FRONT. MAY HAVE TO CONTEND WITH SOME STRATUS IN THE
WAKE OF THE FRONT...AS WELL AS AN INCREASING EAST-SOUTHEAST
WIND...BOTH OF WHICH COULD IMPACT VALLEY FOG FORMATION/PERSISTENCE.
MUCH OF THE COOLING BEHIND THE FRONT STILL APPEARS TO GET DEFLECTED
TO THE EAST...THUS HIGHS ON THURSDAY ARE ONLY ANTICIPATED TO BE
SLIGHTLY COOLER THAN WEDNESDAY.
MUCH OF THE LONG TERM FOCUS IS AFTER MIDNIGHT THURSDAY NIGHT THROUGH
SATURDAY. MODELS REMAIN IN GOOD AGREEMENT ON BUILDING UPPER RIDGING
INTO THE REGION ON FRIDAY...AHEAD OF A SHORTWAVE TROUGH CROSSING THE
NORTHERN ROCKIES. THIS SETS UP A FAIRLY SIGNIFICANT WARM ADVECTION
REGIME OVER THE FORECAST AREA...WITH 850MB TEMPS CLIMBING 8-10C
BETWEEN 00Z FRI AND 00Z SAT. THIS REGIME ALSO COMES WITH MORE
MOISTURE...AS PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.7 INCHES
AT 00Z FRI TO AROUND 1.5 INCHES BY 18Z FRI. THESE TWO PARAMETERS
INCREASING SIGNIFICANTLY BRINGS UP A CONCERN FOR ELEVATED
CONVECTION. 850MB MOISTURE TRANSPORT PROGS FROM THE 16.12Z
NAM/GFS/ECMWF WOULD SUGGEST POSSIBLE CONVECTION FIRING WEST OF I-35
IN MN AND IA BETWEEN 06-12Z FRI...THEN LIFTING NORTHEAST INTO
NORTHERN WI BY 00Z SAT AS CAPPING BUILDS IN. THUS...SOME SHOWER AND
THUNDERSTORM CHANCES PERSIST FOR FRI...ESPECIALLY NORTH OF I-90.
CAPE AND SHEAR PROFILES WOULD SUGGEST NO SEVERE WEATHER WITH THIS
ACTIVITY. GREATER CHANCES FOR WIDESPREAD RAIN LOOK TO COME AFTER
MIDNIGHT FRIDAY NIGHT INTO SATURDAY. THIS IS WHEN THE TROUGH MAKES
ITS WAY EAST AND THROUGH THE REGION...FOLLOWED WITH AN ASSOCIATED
SURFACE COLD FRONT FOR CONVERGENCE. PLENTIFUL MOISTURE CHARACTERIZED
BY THE AFOREMENTIONED 1.5 INCH PRECIPITABLE WATER WILL ALSO HELP.
HARD TO SAY AT THIS TIME IF THE MID LEVEL CIRCULATION OF TROPICAL
STORM ODILE OVER BAJA CALIFORNIA WILL GET PULLED UP INTO THE REGION
OR NOT. IF IT DOES...THE CHANCES FOR PRECIPITATION...AND HEAVY
PRECIPITATION AT THAT WOULD INCREASE. TIMING OF THE FRONT WILL BE
CRITICAL TO WHEN AND WHERE POTENTIAL EXISTS FOR SEVERE WEATHER.
16.12Z ECMWF POINTS TO FRIDAY EVENING ACROSS THE NORTHWEST HALF OF
THE FORECAST AREA...WHILE THE 16.12Z GFS WOULD BE SATURDAY AFTERNOON
OVER THE SOUTHEAST HALF.
SOMETHING ALSO TO KEEP A CLOSE EYE ON IS WINDS ON FRIDAY ACROSS
SOUTHEAST MN. WITH 40 TO PERHAPS AS HIGH AS 60KT SOUTHWEST
WINDS...STRONGEST IF YOU BELIEVE THE NAM...PROGGED BETWEEN 3000-5000
FT ABOVE THE GROUND...MIXING SHOULD EASILY CREATE GUSTS NEAR 30 KT.
THESE IN LATER FORECASTS COULD GET CLOSE TO WIND ADVISORY CRITERIA
IF MORE SUN OCCURS.
FOR SUNDAY INTO TUESDAY...MODELS REAMPLIFY TROUGHING OVER EASTERN
CANADA INTO THE GREAT LAKES REGION...SIMILAR TO WHAT IS GOING ON
TODAY. THERE REMAINS UNCERTAINTY IF A MORE POTENT SHORTWAVE WILL
DIVE THROUGH THE TROUGH AND THROUGH THE FORECAST AREA...BUT TRENDS
SEEM TO SUGGEST THAT THE TRACK OF SUCH WAVE WILL END UP NORTHEAST OF
THE AREA. THEREFORE...THE FORECAST STAYS DRY WITH THE COOLER AIR
STAYING TO THE NORTH AND EAST. STILL...WE SHOULD SEE TEMPERATURES
FALL BACK TO JUST BELOW NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 636 PM CDT TUE SEP 16 2014
SCATTERED TO BROKEN MID LEVEL DECK /5 TO 6KFT/ WILL SKIRT THE TAF
SITES LATER THIS EVENING THROUGH THE OVERNIGHT HOURS AS HIGH
PRESSURE SLIPS OFF TO THE SOUTHEAST. DESPITE T/TD SPREAD OF 3
DEGREES OVERNIGHT AT KLSE...FOG POTENTIAL NEGATED BY INCREASING
SOUTHERLY FLOW JUST OFF THE SURFACE /10 TO 20KTS/ AS WELL AS
PLENTY OF DRYING TODAY. NOT EXPECTING A LONG LIVED OR WIDESPREAD
FOG EVENT. PLAN TO CONTINUE BCFG MENTION AND WATCH TRENDS THIS
EVENING. FOR WEDNESDAY...WINDS WILL SHIFT TO THE NORTHWEST WITH
AFTERNOON CU DEVELOPING BETWEEN 4 AND 6KFT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...ZT
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
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...UPDATED AVIATION
NWS MELBOURNE FL
500 AM EDT WED SEP 17 2014
.DISCUSSION...
CURRENT...
NEARLY SATURATED AIRMASS OVER CENTRAL FL WITH EVENING RAOBS
MEASURING PWAT VALUES BTWN 2.0"-2.2". LATEST RUC ANALYSIS SHOWS A
WELL DEFINED H100-H70 TROF EXTENDING FROM THE NC OUTER BANKS TO THE
NE GOMEX...ASSOCD WITH A STALLED FRONTAL BNDRY OVER THE DEEP SOUTH.
ALOFT...A FEW POCKETS OF NOTEWORTHY MID LVL VORTICITY OVER THE
GOMEX/N FL...UPR LVL DIVERGENCE IS WEAK AS THE CLOSEST H30-H20 JET
STREAK IS LAGGING BACK OVER THE LWR MS VALLEY. MID LVL TEMPS ARE
RUNNING BTWN 7-8C AT H70...AND ARND -7C AT H50...RESULTING IN
UNIMPRESSIVE LAPSE RATES ARND 5.5C/KM.
TODAY-TONIGHT...
A BROAD SFC LOW OVER GA/SC WILL SLOWLY CRANK THE STATIONARY FRONT
INTO CENTRAL FL. PROGRESS WILL BE SLOW...HOWEVER...AS THE JET STREAK
HAS A STRONG ZONAL ORIENTATION THAT PROVIDE LITTLE SWD PUSH. ATLC
RIDGE OVER S FL STRAITS WILL SLOW IT FURTHER...BUT IS QUITE WEAK AND
WILL NOT BE ABLE STOP THE FRONT AS THE LOW LIFTS UP THE ERN SEABOARD.
DEEP MOISTURE COUPLED WITH A THE MID LVL VORTICITY SHOULD ALLOW NMRS
SHRAS AND SCT TSRAS TO DVLP...BUT IT WILL TAKE A WHILE FOR THE LOW
LVL AIRMASS TO DESTABILIZE ENOUGH TO OVERCOME THE WEAK MID LVL LAPSE
RATES. FURTHERMORE...DEEP MOISTURE ALOFT SHOULD PRODUCE MID/UPR LVL
CLOUD DECKS THAT WILL HINDER SFC HEATING. EVEN SO...CANNOT OVERLOOK
SHRA/TSRA ACTIVITY OVER THE ATLC/GOMEX THAT HAS BEEN ONGOING THRU
THE EVENING...ONCE SFC TEMPS REACH THEIR CONVECTIVE TRIGGERS...
PRECIP WILL LIKELY AREAWIDE. OVERALL INSTABILITY LOOKS MODEST AT
BEST...STRONG/SVR TSTM THREAT WILL BE QUITE LOW. SCT SHRAS/TSRAS AFT
SUNSET MAY LINGER INTO EARLY MORNING BUT WILL END AS WINDS VEER TO
THE NW AND PUSH DRIER AND MORE STABLE AIR INTO CENTRAL FL.
CLOUD COVER AND RAIN COOLED AIR WILL KEEP MAX TEMPS NEAR AVG...
GENERALLY IN THE M/U80S. NO MEANINGFUL COLD AIR ADVECTION WILL OCCUR
BEHIND THE FRONT...MIN TEMPS IN THE L/M70S WILL BE SLIGHTLY ABV AVG
DUE TO LINGERING CLOUD COVER.
THU-SAT...
SHORT WAVE ENERGY WILL DIG INTO THE BROAD TROUGH COVERING THE ERN
CONUS AND WRN ATLC...RESULTING IN THE FORMATION OF A CUTOFF LOW
(ALBEIT ELONGATED WITH A POS TILTED AXIS) ACROSS NORTH/CENTRAL FL
AND EXTENDING INTO THE ADJCT ATLC. DEW PT FRONT INITIALLY OVER THE
NORTHERN PENINSULA WILL DRIFT SWD OVER THE REGION AND THEN STALL NEAR
LAKE OKEE AS WEAK LOW PRES WAVE DEVELOPS OFFSHORE THE SERN SEABOARD.
AFTER AN INITIALLY DRIER DAY ON THU...MEAN MOISTURE WILL SHOW SOME
SLIGHT NWD CREEP INTO THE WEEKEND WITH POPS COMING BACK UP TO NEAR
THE CLIMO NORMS (40-50). DEEPEST MOISTURE AND HIGHEST RAIN CHCS WILL
GENERALLY REMAIN CLOSER THE LAKE THROUGH THE PERIOD. TEMPS WILL
TREND SLIGHTLY LOWER ON FRI-SAT COMPARED TO THU OWING TO INCREASING
CLOUD COVER.
SUN-TUE...
THE GFS/ECM MODELS DIFFER SLIGHTLY WITH RESPECT TO THE SPEED IN
WHICH THE (BRIEFLY) CUTOFF LOW OVHD OPENS UP INTO A TROUGH AND
EJECTS NEWD. THE GFS IS FASTER...AND A BIT STRONGER WITH THE
ATTENDANT SFC LOW/WAVE...WHICH DRIES THINGS OUT TO A LITTLE MORE
EXTENT THAN THE ECM SUN. BOTH MODELS SHOW ANOTHER EARLY FALL SEASON
FRONTAL BOUNDARY ENCROACHING UPON THE NORTHERN PENINSULA BY TUE...
POSSIBLY SAGGING SWD INTO THE REGION BY THE MIDDLE OF NEXT WEEK...
BUT TOO EARLY TO SPECULATE AT LENGTH ABOUT ANY SWD PUSH JUST YET.
OVERALL POP TREND WILL BE SLOWLY UPWARD FOR EARLY NEXT WEEK. TEMPS
NOT TOO FAR FROM CLIMO.
&&
.AVIATION...
THRU 17/14Z...PREVAILING VFR ALL SITES WITH W/SW SFC WNDS ARND
5KTS...CIGS AOA FL120...SLGT CHC MVFR SHRAS. BTWN 17/14Z-17/17Z...
SFC WNDS BCMG W BTWN 5-10KTS...PREVAILING CIGS DCRSG TO FL060-080
WITH CHC OF MVFR SHRAS ALL SITES. BTWN 17/17Z-17/24...OCNL WRLY SFC
WND G18KTS...NMRS MVFR SHRAS/SCT IFR TSRAS. BTWN 18/00Z-18/03Z...
SFC WINDS BCMG W/NW AOB 5KTS...SCT MVFR SHRAS/ISOLD IFR TSRAS
ENDING...CIGS AOA FL120.
&&
.MARINE...
TODAY-TONIGHT...
LOW LVL TROF AXIS EXTENDING FROM THE NC OUTER BANKS TO THE NE GOMEX
HAS SUPPRESSED THE ATLC RIDGE AXIS INTO S FL AND THE FL STRAITS.
INTERACTION BTWN THESE TWO WX FEATURES WILL GENERATE A GENTLE TO
MODERATE WRLY BREEZE ACRS THE LCL ATLC THRU THE DAY...BCMG W/NW
OVERNIGHT AS THE TROF AXIS DRIFTS INTO S FL. LATEST OBS FROM BUOY010
SHOW THE MUCH ANTICIPATED SWELL FROM HURRICANE EDOUARD STARTING TO
WORK ITS WAY INTO THE LCL ATLC...THOUGH A BIT SLOWER THAN INDICATED
BY THE WAVE MODELS. SEAS WILL BUILD THRU THE DAY... REACHING 3-4FT
NEARSHORE AND 5-6FT OFFSHORE WITH DOMINANT PDS AOA 13SEC. THIS MAY
CAUSE VERY ROUGH CONDITIONS NEAR THE MOUTHS OF INLETS DURING THE
OUTGOING MORNING TIDE.
RIP CURRENTS: LONG PERIOD SWELLS WILL START TO AFFECT THE COAST WED
MORNING...RESULTING IN DANGEROUS SURF CONDITIONS AND A HIGH RISK OF
DANGEROUS RIP CURRENTS.
THU-SUN...
ANY RESIDUAL SWELL FROM EDOUARD WILL BE WANING THU...WITH MINIMAL
WIND CHOP INDICATED INTO THIS WEEKEND. WINDS GENERALLY BELOW 15KT
WITH SEAS MOSTLY IN THE 2-3FT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 87 73 89 73 / 60 30 20 10
MCO 90 73 92 72 / 60 30 20 10
MLB 89 73 87 75 / 60 40 20 10
VRB 89 72 89 73 / 60 40 20 10
LEE 89 73 93 74 / 60 30 20 10
SFB 90 73 92 75 / 60 30 20 10
ORL 90 73 91 75 / 60 30 20 10
FPR 88 72 89 72 / 60 40 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....CRISTALDI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 AM EDT WED SEP 17 2014
.DISCUSSION...
CURRENT...
NEARLY SATURATED AIRMASS OVER CENTRAL FL WITH EVENING RAOBS
MEASURING PWAT VALUES BTWN 2.0"-2.2". LATEST RUC ANALYSIS SHOWS A
WELL DEFINED H100-H70 TROF EXTENDING FROM THE NC OUTER BANKS TO THE
NE GOMEX...ASSOCD WITH A STALLED FRONTAL BNDRY OVER THE DEEP SOUTH.
ALOFT...A FEW POCKETS OF NOTEWORTHY MID LVL VORTICITY OVER THE
GOMEX/N FL...UPR LVL DIVERGENCE IS WEAK AS THE CLOSEST H30-H20 JET
STREAK IS LAGGING BACK OVER THE LWR MS VALLEY. MID LVL TEMPS ARE
RUNNING BTWN 7-8C AT H70...AND ARND -7C AT H50...RESULTING IN
UNIMPRESSIVE LAPSE RATES ARND 5.5C/KM.
TODAY-TONIGHT...
A BROAD SFC LOW OVER GA/SC WILL SLOWLY CRANK THE STATIONARY FRONT
INTO CENTRAL FL. PROGRESS WILL BE SLOW...HOWEVER...AS THE JET STREAK
HAS A STRONG ZONAL ORIENTATION THAT PROVIDE LITTLE SWD PUSH. ATLC
RIDGE OVER S FL STRAITS WILL SLOW IT FURTHER...BUT IS QUITE WEAK AND
WILL NOT BE ABLE STOP THE FRONT AS THE LOW LIFTS UP THE ERN SEABOARD.
DEEP MOISTURE COUPLED WITH A THE MID LVL VORTICITY SHOULD ALLOW NMRS
SHRAS AND SCT TSRAS TO DVLP...BUT IT WILL TAKE A WHILE FOR THE LOW
LVL AIRMASS TO DESTABILIZE ENOUGH TO OVERCOME THE WEAK MID LVL LAPSE
RATES. FURTHERMORE...DEEP MOISTURE ALOFT SHOULD PRODUCE MID/UPR LVL
CLOUD DECKS THAT WILL HINDER SFC HEATING. EVEN SO...CANNOT OVERLOOK
SHRA/TSRA ACTIVITY OVER THE ATLC/GOMEX THAT HAS BEEN ONGOING THRU
THE EVENING...ONCE SFC TEMPS REACH THEIR CONVECTIVE TRIGGERS...
PRECIP WILL LIKELY AREAWIDE. OVERALL INSTABILITY LOOKS MODEST AT
BEST...STRONG/SVR TSTM THREAT WILL BE QUITE LOW. SCT SHRAS/TSRAS AFT
SUNSET MAY LINGER INTO EARLY MORNING BUT WILL END AS WINDS VEER TO
THE NW AND PUSH DRIER AND MORE STABLE AIR INTO CENTRAL FL.
CLOUD COVER AND RAIN COOLED AIR WILL KEEP MAX TEMPS NEAR AVG...
GENERALLY IN THE M/U80S. NO MEANINGFUL COLD AIR ADVECTION WILL OCCUR
BEHIND THE FRONT...MIN TEMPS IN THE L/M70S WILL BE SLIGHTLY ABV AVG
DUE TO LINGERING CLOUD COVER.
THU-SAT...
SHORT WAVE ENERGY WILL DIG INTO THE BROAD TROUGH COVERING THE ERN
CONUS AND WRN ATLC...RESULTING IN THE FORMATION OF A CUTOFF LOW
(ALBEIT ELONGATED WITH A POS TILTED AXIS) ACROSS NORTH/CENTRAL FL
AND EXTENDING INTO THE ADJCT ATLC. DEW PT FRONT INITIALLY OVER THE
NORTHERN PENINSULA WILL DRIFT SWD OVER THE REGION AND THEN STALL NEAR
LAKE OKEE AS WEAK LOW PRES WAVE DEVELOPS OFFSHORE THE SERN SEABOARD.
AFTER AN INITIALLY DRIER DAY ON THU...MEAN MOISTURE WILL SHOW SOME
SLIGHT NWD CREEP INTO THE WEEKEND WITH POPS COMING BACK UP TO NEAR
THE CLIMO NORMS (40-50). DEEPEST MOISTURE AND HIGHEST RAIN CHCS WILL
GENERALLY REMAIN CLOSER THE LAKE THROUGH THE PERIOD. TEMPS WILL
TREND SLIGHTLY LOWER ON FRI-SAT COMPARED TO THU OWING TO INCREASING
CLOUD COVER.
SUN-TUE...
THE GFS/ECM MODELS DIFFER SLIGHTLY WITH RESPECT TO THE SPEED IN
WHICH THE (BRIEFLY) CUTOFF LOW OVHD OPENS UP INTO A TROUGH AND
EJECTS NEWD. THE GFS IS FASTER...AND A BIT STRONGER WITH THE
ATTENDANT SFC LOW/WAVE...WHICH DRIES THINGS OUT TO A LITTLE MORE
EXTENT THAN THE ECM SUN. BOTH MODELS SHOW ANOTHER EARLY FALL SEASON
FRONTAL BOUNDARY ENCROACHING UPON THE NORTHERN PENINSULA BY TUE...
POSSIBLY SAGGING SWD INTO THE REGION BY THE MIDDLE OF NEXT WEEK...
BUT TOO EARLY TO SPECULATE AT LENGTH ABOUT ANY SWD PUSH JUST YET.
OVERALL POP TREND WILL BE SLOWLY UPWARD FOR EARLY NEXT WEEK. TEMPS
NOT TOO FAR FROM CLIMO.
&&
.AVIATION...
THRU 17/14Z...VFR ALL SITES WITH W/SW SFC WNDS ARND 5KTS...CIGS AOA
FL120...SLGT CHC MVFR SHRAS W OF KLEE-KOBE. BTWN 17/14Z-17/17Z...SFC
WNDS BCMG W BTWN 5-10KTS...PREVAILING CIGS DCRSG TO FL060-080 WITH
CHC OF MVFR SHRAS ALL SITES. BTWN 17/17Z-17/24...OCNL WRLY SFC WND
G18KTS...NMRS MVFR SHRAS/SCT IFR TSRAS. AFT 18/00Z...
&&
.MARINE...
TODAY-TONIGHT...
LOW LVL TROF AXIS EXTENDING FROM THE NC OUTER BANKS TO THE NE GOMEX
HAS SUPPRESSED THE ATLC RIDGE AXIS INTO S FL AND THE FL STRAITS.
INTERACTION BTWN THESE TWO WX FEATURES WILL GENERATE A GENTLE TO
MODERATE WRLY BREEZE ACRS THE LCL ATLC THRU THE DAY...BCMG W/NW
OVERNIGHT AS THE TROF AXIS DRIFTS INTO S FL. LATEST OBS FROM BUOY010
SHOW THE MUCH ANTICIPATED SWELL FROM HURRICANE EDOUARD STARTING TO
WORK ITS WAY INTO THE LCL ATLC...THOUGH A BIT SLOWER THAN INDICATED
BY THE WAVE MODELS. SEAS WILL BUILD THRU THE DAY... REACHING 3-4FT
NEARSHORE AND 5-6FT OFFSHORE WITH DOMINANT PDS AOA 13SEC. THIS MAY
CAUSE VERY ROUGH CONDITIONS NEAR THE MOUTHS OF INLETS DURING THE
OUTGOING MORNING TIDE.
RIP CURRENTS: LONG PERIOD SWELLS WILL START TO AFFECT THE COAST WED
MORNING...RESULTING IN DANGEROUS SURF CONDITIONS AND A HIGH RISK OF
DANGEROUS RIP CURRENTS.
THU-SUN...
ANY RESIDUAL SWELL FROM EDOUARD WILL BE WANING THU...WITH MINIMAL
WIND CHOP INDICATED INTO THIS WEEKEND. WINDS GENERALLY BELOW 15KT
WITH SEAS MOSTLY IN THE 2-3FT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 87 73 89 73 / 60 30 20 10
MCO 90 73 92 72 / 60 30 20 10
MLB 89 73 87 75 / 60 40 20 10
VRB 89 72 89 73 / 60 40 20 10
LEE 89 73 93 74 / 60 30 20 10
SFB 90 73 92 75 / 60 30 20 10
ORL 90 73 91 75 / 60 30 20 10
FPR 88 72 89 72 / 60 40 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....CRISTALDI
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1158 PM MDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 823 PM MDT TUE SEP 16 2014
BASED ON LATEST MODEL DATA AND SINCE THERE HAS NOT BEEN ANY FOG
DEVELOPMENT OVER THE LAST 3 MORNINGS WHEN MODELS WERE FORECASTING
FOG...HAVE CUT BACK ON THE AREA/COVERAGE OF FOG FOR THE
OVERNIGHT/MORNING HOURS. DID KEEP A MENTION OF FOG IN THE FORECAST
WHERE THE SREF HAS ATLEAST 50 PERCENT CONFIDENCE OF LESS THAN
A MILE VISIBILITY. AM NOT TOO CONCERNED AT THIS TIME ABOUT
REDUCED VISIBILITIES IF FOG DOES DEVELOP...BUT WILL SEE HOW THE
NIGHT GOES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 147 PM MDT TUE SEP 16 2014
AS OF 2 PM CDT...1 PM MDT...SKIES ACROSS THE TRI-STATE AREA WITH THE
REMAINING EXCEPTION OF ERODING STRATUS EAST OF A MCCOOK NEBRASKA TO
GOVE KANSAS LINE. TEMPERATURES WERE IN THE MID 70S TO MID 80S WHERE
SKIES HAVE CLEARED AND IN THE UPPER 60S TO LOW 70S WHERE STRATUS
REMAINS. WINDS WERE FROM THE SOUTH TO SOUTHWEST AT 10 TO 15 MPH...
GUSTING AS HIGH AS 25 MPH. A LEE TROUGH WAS LOCATED OVER NORTHEAST
COLORADO...SLOWLY PROGRESSING EAST INTO SOUTHWEST NEBRASKA. NO
SIGNIFICANT WEATHER DISTURBANCES WERE NOTED MOVING TOWARDS THE TRI-
STATE AREA.
FOR TONIGHT INTO TOMORROW...MAIN FORECAST CONCERN IS THE CHANCE FOR
FOG LATE TONIGHT/EARLY WEDNESDAY MORNING. BASED ON THE ANTICIPATED
LOCATION OF THE LEE TROUGH...POOLING MOISTURE EAST OF THE TROUGH AND
LIGHT/CALM WINDS...LIMITED THE POTENTIAL FOG TO PORTIONS OF
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. THE BEST CHANCES FOR FOG
SHOULD RESIDE NORTH AND EAST OF A LINE FROM STRATTON NEBRASKA TO
HOXIE TO HILL CITY KANSAS. IT IS INTERESTING TO NOTE THAT THE
NAM...WRF NMM...AND THE RUC13 INDICATE A POTENTIAL FOR DENSE FOG.
FUTURE SHIFTS WILL NEED TO MONITOR THIS THREAT BUT FOR NOW...DID NOT
PLACE DENSE WORDING INTO THE GRIDS.
FOR TOMORROW...WARMER WEATHER IS ANTICIPATED REGION-WIDE AS MOST OF
THE AREA SHOULD REMAIN FREE OF CLOUD COVER AND LOCATIONS THAT
EXPERIENCE FOG SHOULD SEE FOG LIFT AND DISSIPATE MUCH QUICKER THAN
STRATUS TODAY. ONE ITEM TO NOTE IS THE ECMWF...NAM12 AND WRF-NMM
DEVELOP A COUPLE SHOWERS/THUNDERSTORMS OVER EAST CENTRAL COLORADO
AND WEST CENTRAL KANSAS. INSTABILITY IS AROUND 1000-1500 J/KG OF
CAPE. HOWEVER...WITH A STRONG CAPE IN PLACE...WEAK SURFACE
CONVERGENCE AND LITTLE INDICATION OF A STRONG ENOUGH SHORTWAVE TO
OVERCOME THE CAP...DID NOT FEEL CONFIDENT ENOUGH TO MENTION A CHANCE
OF THUNDERSTORMS TOMORROW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM MDT TUE SEP 16 2014
WEDNESDAY NIGHT-THURSDAY NIGHT...UPPER RIDGE AXIS SHIFTS EAST OVER
THE AREA THURSDAY THEN SLOWLY EAST THURSDAY NIGHT. NAM MODEL HAS
BACKED OFF ON WESTWARD PUSH OF FRONTAL BOUNDARY AND POST-FRONTAL
STRATUS WEDNESDAY NIGHT...NOW LIMITING IT TO AREAS ACROSS FAR
SOUTHWEST NEBRASKA TO NORTON AND HILL CITY AREAS...SIMILAR TO THE
06Z GFS. NAM VISIBILITY FORECASTS FOR FOG IN THE STRATUS HAVE BEEN
HORRIBLE THE PAST WEEK OR SO...OVERDOING IT SIGNIFICANTLY.
HOWEVER...WITH A LIGHT EAST WIND VS SOUTHERLY THE PAST FEW POTENTIAL
EVENTS CANT RULE OUT SOME FOG SO HAVE KEPT IT GOING BUT BACKED OFF
COVERAGE JUST A BIT.
SOME ELEVATED THUNDERSTORMS POSSIBLE THROUGH MIDNIGHT WEDNESDAY
NIGHT FROM MCCOOK TO HILL CITY AND POINTS EAST WITH DECREASING
CHANCES SHORTLY AFTER AS INSTABILITY AXIS SLOWLY SHIFTS EAST.
SUNNY/MOSTLY SUNNY AND DRY THURSDAY WITH MOSTLY CLEAR CONDITIONS
THURSDAY NIGHT. A FEW CLOUDS MAY CREEP INTO THE FAR SOUTH AND
SOUTHWEST PARTS OF THE AREA HEAD OF (AS OF THIS WRITING) TROPICAL
STORM ODILE.
LOWS WEDNESDAY NIGHT IN THE MID 50S TO LOW 60S...WARMING A FEW
DEGREES FOR THURSDAY NIGHT. HIGHS THURSDAY MID 80S TO AROUND 90/LOW
90S.
FRIDAY-FRIDAY NIGHT...MOISTURE ASSOCIATED WITH (AS OF THIS WRITING)
TROPICAL STORM ODILE FORECAST TO REACH AREAS GENERALLY ALONG AND
SOUTH OF THE INTERSTATE BY 00Z SATURDAY WITH THE NAM/ECMWF FURTHEST
NORTH AND GFS QUITE A BIT TO THE SOUTH...NOT EVEN REACHING KANSAS.
FOR THIS FORECAST CYCLE HAVE TRIMMED BACK ON NORTHWARD EXTENT OF
PRECIPITATION CHANCES BY 18Z TO AREAS SOUTH OF A TRIBUNE AND LEOTI LINE.
FOR FRIDAY NIGHT GENERAL IDEA IS FOR ODILES MOISTURE TO CONTINUE
TOWARD NORTON AND HILL CITY BY 06Z BEFORE EXITING TO THE EAST AS
AN UPPER TROUGH APPROACHES FROM THE NORTHWEST.
HIGHS IN THE 80S. LOWS IN THE MID 50S TO LOW 60S...COOLEST IN FAR
EASTERN COLORADO.
SATURDAY...MID AND HIGH CLOUDS INCREASE FROM THE NORTHWEST
ASSOCIATED UPPER TROUGH PASSAGE. PLENTY OF LOW CLOUDS REMAIN ACROSS
THE SOUTHEAST HALF OF THE AREA DURING THE MORNING BEFORE DECREASING
FROM NORTHWEST TO SOUTHEAST WITH THE TROUGH. ENOUGH INSTABILITY
PRESENT TO WARRANT A SLIGHT CHANCE OF THUNDERSTORMS. DRY WEATHER
EXPECTED SATURDAY NIGHT. HIGHS IN THE MID 70S TO LOW 80S. LOWS IN
THE LOW TO MID 50S.
SUNDAY...DRY WEATHER EXPECTED. HIGHS IN THE MID TO UPPER 70S
WITH LOWS IN THE LOW TO MID 50S.
MONDAY-TUESDAY...WILL BE WATCHING MOISTURE/CLOUDINESS WORKS ITS WAY
TOWARD THE WESTERN 1/2 OF THE AREA AHEAD OF AN UPPER LOW PRESSURE
SYSTEM MAKING ITS WAY INTO THE GREAT BASIN AREA FROM THE SOUTHWEST.
MAY SEE A FEW SHOWERS/THUNDERSTORMS GENERALLY ALONG/WEST OF THE
CO/KS BORDER TUESDAY.
HIGHS BOTH DAYS IN THE 70S WITH LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1153 PM MDT TUE SEP 16 2014
VFR TO MVFR CONDITIONS FORECAST FOR THE 6Z TAFS. LATEST MODEL DATA
CONTINUING TO SUGGEST LOW VIS/CEILINGS FOR THE MORNING AT KMCK.
AM STILL HESITANT TO GO MUCH BELOW MVFR DUE TO PERSISTENT FROM
PREVIOUS DAYS...SO WILL GO TOWARD THE LOWER END OF MVFR.
CLIMATOLOGY SUGGESTS MVFR CEILINGS ARE SLIGHTLY MORE PROBABLE THAN
IFR WHICH ADDS A BIT MORE CONFIDENCE TO THE FORECAST...ALTHOUGHIFR
SLIGHTLY MORE LIKELY THAN MVFR FOR THE VIS. IN THE CLIMATOLOGY.
OTHERWISE LIGHT WINDS WILL PREVAIL THROUGH THE TAF WINDOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...RRH
LONG TERM...99
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS JACKSON KY
149 AM EDT WED SEP 17 2014
.UPDATE...
ISSUED AT 149 AM EDT WED SEP 17 2014
UPDATED TO RAMP UP THE SKY COVER HAS STRATUS IS CONTINUING TO EXPAND
THIS MORNING. ALSO...TWEAKED TEMPERATURES UP A TAD AS THE CLOUDS ARE
NOT ALLOWING TEMPERATURES TO COOL BY QUITE AS MUCH AS EARLIER
ANTICIPATED. OTHERWISE...NO OTHER CHANGES.
UPDATE ISSUED AT 1135 PM EDT TUE SEP 16 2014
ADJUSTED OVERNIGHT LOWS BASED ON CURRENT TRENDS...GENERALLY A LITTLE
COOLER IN THE NORTH. AFTERNOON POST FRONTAL CLOUDS CONTINUE TO ERODE
AS SUBSIDENCE ALOFT DRIES OUT THE ATMOSPHERE JUST ABOVE THE BOUNDARY
LAYER. CONSEQUENTLY AS SKIES CLEAR...LOWER STRATUS AND FOG HAVE BEEN
REDEVELOPING DUE TO NEAR IDEAL RADIATIVE CONDITIONS ALOFT AT THE TOP
OF THE RESIDUAL MOIST BOUNDARY/SURFACE LAYER OVER OUR FORECAST AREA.
BEEFED UP FOG IN THE GRIDS AND ZONES. ATTM NOT EXACTLY SURE HOW
WIDESPREAD FOG FORMATION WILL BE OVERNIGHT DUE TO EVENTUAL STRENGTH
OF SFC WINDS AND MIXING. AFTER DISCUSSIONS WITH NEIGHBORS...DECIDED
TO ISSUE A SPECIAL WEATHER STATEMENT TO HIGHLIGHT FOG POTENTIAL.
UPDATE ISSUED AT 858 PM EDT TUE SEP 16 2014
QUICK UPDATE TO THE ZONES TO REMOVE SPRINKLES. BROUGHT GRIDS IN LINE
WITH HOURLY OBS...TEMPS DROPPING A BIT FASTER THAN ANTICIPATED WITH
PARTIAL CLEARING. HOWEVER OVERNIGHT MINS STILL LOOK ON TRACK FOR NOW.
UPDATE ISSUED AT 713 PM EDT TUE SEP 16 2014
FORECAST IS IN GOOD SHAPE. TWEAKED GRIDS TO HOURLY OBSERVATIONS.
STILL SEEING SOME VERY LIGHT ECHOS ACROSS THE SOUTHEAST. THEREFORE
WILL HOLD OFF ON ANY UPDATE TO THE ZFP FOR A BIT LONGER BEFORE
REMOVING LIGHT SPRINKLE ACTIVITY. REGIONAL SATELLITE IS SHOWING DECENT
AMOUNT OF CLOUD EROSION AS DRY AIR FROM DEVELOPING SUBSIDENCE
INVERSION ALOFT MIXES INTO THE TOP OF THE BOUNDARY LAYER. RELATIVELY
HIGH SFC DEW POINTS REMAIN HOWEVER. CONCERN IS THAT WITH STRONG
SUBSIDENCE AND THEREFORE DRYING TAKING PLACE JUST ABOVE THE BOUNDARY
LAYER...RADIATIVE COOLING WILL BE THE CATALYST FOR LOW STRATUS AND
FOG TO REDEVELOP OVERNIGHT. WILL KEEP A CLOSE EYE ON OBSERVATIONS
THROUGH THE EVENING IN CASE A HEADLINE IS NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 350 PM EDT TUE SEP 16 2014
19Z SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXITING FAR SOUTHEAST
KENTUCKY AS A COOL AND DRY AREA OF HIGH PRESSURE PUSHES DEEPER INTO
THE OHIO VALLEY. BEHIND THIS BOUNDARY...A FEW LIGHT SHOWERS AND
PLENTY OF SPRINKLES/DRIZZLE REMAIN OVER A GOOD PORTION OF THE CWA.
ON SATELLITE...THE LOW CLOUDS ARE BREAKING UP OVER THE SOUTHERN
PORTION OF EAST KENTUCKY WHILE THEY ARE HOLDING TIGHT OVER JKL AND
POINTS NORTH. THE EXTENSIVE CLOUD COVER AND POCKETS OF LIGHT PCPN
KEPT TEMPERATURES WELL BELOW NORMAL FOR THE DAY WITH READINGS
CURRENTLY RANGING FROM A CHILLY 60 DEGREES ALONG AND NORTH OF
INTERSTATE 64 WHILE SOME 70 DEGREE READINGS HAVE SHOWN UP TO THE
SOUTH THANKS TO PARTIAL SUNSHINE. DEW POINTS VARY FROM THE MID 50S
NORTH TO THE LOWER AND MIDDLE 60S SOUTH. LIGHT NORTH WINDS ARE ADDING
TO THE CHILL THROUGH MOST OF THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH EAST KENTUCKY STILL IN
THE GRIP OF A BROAD AND UNSEASONABLY DEEP TROUGH THROUGH THE EASTERN
HALF OF THE NATION. FAIRLY FAST NORTHWEST FLOW AT THE BASE OF THIS
TROUGH WILL KEEP A SERIES OF WEAK DISTURBANCES MOVING THROUGH EAST
KENTUCKY DURING THE SHORT TERM PORTION OF THE FORECAST. THE
HEALTHIEST OF THESE ACTUALLY PASSES THROUGH DURING THE DAY WEDNESDAY
WITH A KINK IN THE FLOW LINES. GIVEN THE MODEL SIMILARITIES ALOFT
HAVE GONE WITH A GENERAL BLEND WHILE FAVORING THE HRRR AND NAM12
THROUGH THE FIRST 18 TO 24 HOURS.
SENSIBLE WEATHER WILL FEATURE THE LINGERING SHOWERS AND POCKETS OF
SPRINKLES/DRIZZLE DRYING UP BY EARLY EVENING WITH SOME CLEARING
EXPECTED FOR A TIME. HOWEVER...THIS CLEARING...WITH LITTLE IN THE
WAY OF SFC WINDS...WILL LIKELY ALLOW AREAS OF DENSE FOG AND LOW
STRATUS TO DEVELOP...RESTRICTING VISIBILITY IN MOST PLACES ACROSS
EAST KENTUCKY BY DAWN. HAVE HIT THIS HARD IN THE GRIDS AND ALSO THE
HWO. WILL LEAVE IT TO LATER SHIFTS TO MONITOR THE CLEARING...
ADVECTION...AND PRELIMINARY FOG PRODUCTION FOR A POTENTIAL ADVISORY
OR SPS. ONCE THE FOG BURNS OFF ON WEDNESDAY MORNING SOME SUNSHINE CAN
BE EXPECTED... BUT THE UPPER LEVEL ENERGY WILL LIKELY BRING IN MORE
LOW AND MID LEVEL CLOUDS. IN FACT...CANNOT COMPLETELY RULE OUT SOME
MORE SPRINKLES OR A LIGHT SHOWER AS THIS WAVE MOVES BY ALOFT
WEDNESDAY AFTERNOON. FOR NOW...THOUGH...HAVE KEPT THE POPS JUST BELOW
MENTIONING. THE WAKE OF THIS WILL SET UP ANOTHER NIGHT OF AT LEAST
PARTIAL CLEARING ALONG WITH AREAS OF FOG...LOCALLY DENSE FORMING LATE
AT NIGHT. THIS SHOULD BE THE COLDER OF THE NIGHTS WITH SOME UPPER 40S
POSSIBLE IN THE VALLEYS THROUGH THE NORTHERN HALF OF THE AREA...AND
ELSEWHERE IF THE CLEARING AND FOG ALLOW IT.
AGAIN 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 NUDGE THE LOWS TONIGHT AND ESPECIALLY WEDNESDAY NIGHT FOR RIDGE
AND VALLEY DIFFERENCES. AS FOR POPS...ENDED UP HIGHER THAN MOS IN THE
NEAR TERM AND ALSO FOR LATER WEDNESDAY...OTHERWISE KEPT THE POPS LOW
SIMILAR TO THE GUIDANCE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 PM EDT TUE SEP 16 2014
THURSDAY MORNING STARTS THE EXTENDED PERIOD WITH AN AMPLIFIED UPPER
LEVEL PATTERN. STRONG TROUGHING WILL EXIST ACROSS MUCH OF THE
EASTERN THIRD OF THE CONUS...WHILE HIGH PRESSURE RIDGING REMAINS
PARKED ACROSS THE SOUTHWESTERN STATES. THIS PATTERN WILL REMAIN IN
PLACE THROUGH FRIDAY...BEFORE IT STARTS TO BREAK DOWN AND HEIGHTS
BEGIN TO BUILD ACROSS EASTERN KY INTO THE DAY SATURDAY. N/NW WINDS
WILL USHER IN COLD WINDS DURING THE DAY THURSDAY...WITH HIGHS ONLY
REACHING THE LOW TO MID 70S. THIS WILL NOT
CONTINUE...HOWEVER...AS A SHORTWAVE MOVES TOWARDS THE REGION DURING
THE DAY FRIDAY. AT THE SURFACE...A POTENT COLD FRONT WILL BE MAKING
ITS WAY FROM THE NORTHERN PLAINS TOWARDS KY...WITH SRLY WINDS
PULLING UP WARM AIR OUT AHEAD OF THE FRONT. THIS WILL RESULT IN
INCREASING TEMPERATURES FRIDAY...REACHING MORE SEASONABLE UPPER 70S
AND LOW 80S FOR BOTH FRIDAY AND SATURDAY.
THE FRONT WILL LOSE STRENGTH AS IT MOVES TOWARDS THE EASTERN KY
REGION AS UPPER LEVEL HEIGHTS CONTINUE TO BUILD INTO THE WEEKEND. BY
THE TIME THE SYSTEM REACHES EASTERN KY...THERE WILL BE VERY LITTLE
INSTABILITY LEFT...AS WELL AS VERY LITTLE CONCERN FOR PWAT VALUES.
MODELS ARE STILL SLIGHTLY DIFFERENT ON THE EXACT TIMING AND EXTENT
OF THE PRECIPITATION...SO WILL CONTINUE TO STICK CLOSE TO A MODEL
BLEND. AS SUCH...EXPECT THE PRECIP TO MOVE AHEAD OF THE FRONT AND
INTO EASTERN KY BETWEEN 12 AND 18Z SUNDAY...AND CONTINUE INTO EARLY
AFTERNOON MONDAY. DESPITE LACK OF INSTABILITY...NEIGHBORING OFFICES
CONTINUE TO FAVOR THE FACT THAT THE FRONTAL BOUNDARY LIFT ALONE MAY
BE ENOUGH TO INITIATE SOME THUNDER. AS SUCH...KEPT IN ONLY SLIGHT
MENTION OF THUNDER AS THE LINE MAKES IT THROUGH KY SUNDAY INTO
MONDAY...WITH THE EXCEPTION OF SUNDAY AFTERNOON...WHERE IT SEEMS THE
INCOMING FRONT WILL BRING A BRIEF PERIOD OF HEIGHTENED INSTABILITY
WITH AFTERNOON HEATING...AND THEREFORE CHANCES WERE INCLUDED.
TEMPS WILL COOL SUBSTANTIALLY BEHIND THE FRONTAL PASSAGE BY DURING
THE DAY MONDAY. UPPER LEVEL RIDGING WILL SLOWLY MOVE IN OVERHEAD
INTO THE DAY TUESDAY...WHILE AT THE SURFACE BROAD HIGH PRESSURE
TAKES CONTROL. SURFACE WINDS WILL BECOME MORE NORTHERLY...AS STRONG
W/NW WINDS ALOFT. THIS WILL RESULT IN THE RETURN OF ANOTHER
UNSEASONABLY COOL AIR MASS AND HIGH TEMPERATURES ONLY TOPPING OUT IN
THE LOW TO MID 70S. TEMPS WILL CONTINUE TO DETERIORATE BY THE DAY
TUESDAY...WITH HIGHS IN THE UPPER 60S TO AROUND 70S EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 149 AM EDT WED SEP 17 2014
STRATUS CONTINUES TO DEVELOP AND SLOWLY BUILD DOWN. THIS WILL
CONTINUE THROUGH DAYBREAK...WITH THE RIDGE TOPS REALLY GETTING SOCKED
IN OVER THE NEXT FEW HOURS. FOG MAY BE MORE SPORADIC IN THE VALLEYS
AND NOT QUITE AS DENSE. HOWEVER...GIVEN MANY OF THE RIDGETOP
AIRPORTS...THIS WILL BRING MANY SPOTS BELOW AIRPORT MINIMUMS LATE
TONIGHT. FOG/STRATUS WILL BEGIN TO LIFT/BURN OFF AFTER SUNRISE...BUT
MAY TAKE A GOOD 2 TO 3 HOURS BEFORE THIS PROCESS IS COMPLETE. WE
SHOULD SEE A RETURN TO VFR CONDITIONS FOR ALL AREAS BY LATE MORNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT WED SEP 17 2014
LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A SHORTWAVE MOVING
INTO WRN ONTARIO WITH ITS ASSOC UPPER JET MAX PASSING ACROSS THE TIP
OF JAMES BAY. 850 MB FGEN ALONG THE SYSTEMS COLD FRONT IS SUPPORTING
BAND OF SHRA FROM JUST NORTH OF MN BDR EXTENDING ACROSS NCNTRL AND
ERN LAKE SUPERIOR AS NOTED ON CANADIAN RADAR MOSIAC. SOME OF THESE
SHRA HAVE BRUSHED THE KEWEENAW PENINSULA EARLY THIS MORNING AND LOW
CLOUDS HAVE REACHED INTO KCMX AS WELL. OTHERWISE THE REST OF THE CWA
HAS STAYED DRY THUS FAR.
TODAY...AS THE ONTARIO SHORTWAVE DIVES ACROSS THE NRN TIP OF LAKE
SUPERIOR LATER THIS MORNING IT WILL HELP DRIVE THE COLD FRONT ACROSS
UPPER MI LATE THIS MORNING INTO THE AFTERNOON HRS. MODELS SHOW
SUPPORTING 850 MB FGEN FORCING FOR SHRA ACTIVITY GENERALLY WEAKENING
AND MOVING EAST BY LATE MORNING WITH DEPARTING SHORTWAVE AND ASSOC
UPPER JET MAX AS COLD FRONT SLOWLY BEGINS TO SHIFT SOUTH ACROSS THE
AREA. SINCE THE MODELS INDICATE THE BEST FGEN FORCING GENERALLY
STAYING OUT OVER LAKE SUPERIOR OR NORTH OF THE LAKE THROUGH LATE
MORNING HAVE KEPT HIGHER CHC/LIKELY POPS WELL NORTH OVER LAKE
SUPERIOR THIS MORNING WITH ONLY SLIGHT CHC TO LOW CHC POPS BRUSHING
THE KEWEENAW PENINSULA AND THE FAR NE CWA. THE REST OF THE CWA SHOULD
STAY GENERALLY DRY TODAY AS FGEN WILL BE WEAKENING QUICKLY ALONG THE
FRONT AS IT BEGINS TO MOVE SOUTH ACROSS UPPER MI THIS AFTERNOON.
SINCE COLD FRONTAL PASSAGE WILL BE LATER IN THE DAY FOR ALL BUT THE
NW QUARTER OF THE CWA...EXPECT TEMPS TO WARM UP INTO THE 60S OVER
SCNTRL AND ERN PORTIONS OF THE CWA WITH THE COOLEST TEMPS (AROUND
50F) ACROSS THE KEWEENAW PENINSULA. TEMPS ACROSS THE N WILL LIKELY
FALL INTO THE 40S IN THE AFTN UNDER A BRISK DEVELOPING NRLY WIND AND
STRATUS DECK FOLLOWING FROPA.
TONIGHT...CANADIAN HIGH PRESSURE BUILDING ACROSS THE AREA AND
BECOMING CENTERED NE OF LAKE SUPERIOR WILL BRING CLEARING SKIES AND
LIGHT EASTERLY WINDS. PWATS LESS THAN 30 PCT OF NORMAL OR LESS THAN
.25 INCH WILL ALLOW FOR IDEAL RADIATIONAL COOLING CONDITIONS. EXPECT
FREEZING TO BLO FREEZING TEMPS ACROSS MUCH OF THE INTERIOR OF THE
UPPER MI. HAVE POSTED FREEZE WARNINGS FOR THE INTERIOR WRN COUNTIES
AND HAVE FROST ADVISORIES OUT FOR THE REST OF THE CWA WITH THE
EXCEPTION OF KEWEENAW COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM EDT WED SEP 17 2014
NOT MUCH CHANGE IN THINKING FROM PREVIOUS SHIFT. THU WILL START WITH
LINGERING COLD AND FROST FROM WED NIGHT AS A 1025MB SFC HIGH WILL BE
CENTERED JUST NE OF THE CWA AT 12Z THU. THE HIGH WILL MOVE TO NEW
ENGLAND...WHILE STRENGTHENING TO 1030MB...BY 12Z FRI WHILE A SFC
TROUGH MOVES TO THE DAKOTAS. RETURN FLOW/WAA WILL JUST BE STARTING
LATE THU...SO DRY AIR LINGERING OVER THE REGION WILL MAKE FOR MOSTLY
SUNNY SKIES ON THU. TEMPS ON THU WILL TOP OUT IN THE MID TO UPPER
50S.
MOISTURE BEGINS TO INCREASE THU NIGHT AS THE RETURN FLOW
INCREASES...BUT MOST PRECIP LOOKS TO HOLD OFF UNTIL FRI WHEN AMPLE
MOISTURE WILL BE ESTABLISHED...A SERIES OF SHORTWAVE TROUGHS BEGINS
A TREK ACROSS THE AREA...AND THE PRESSURE GRADIENT/RETURN FLOW
INCREASES. MODELS ARE IN GOOD AGREEMENT ON THE START TIME OF PRECIP
FRI IN THE WAA REGIME...BUT HOW THINGS SHAPE UP ON FRIDAY AND
ESPECIALLY THE END TIME OF PRECIP ON SAT NIGHT OR SUN IS MORE
UNCERTAIN. EVEN THOUGH MODELS AGREE THAT THE STRONGEST SHORTWAVE
WILL ENTER THE REGION LATE SAT INTO SAT NIGHT...MODELS DISAGREE WITH
EACH OTHER AND FROM RUN TO RUN DUE TO THE COMPLEX NATURE OF PHASING
THE THREE WAVES OVER THE AREA. WILL LIKELY NOT HAVE GREATER
CERTAINTY ON END TIME OF PRECIP UNTIL CLOSER TO THE WEEKEND. HAVE
THE GREATEST POPS FROM LATE FRI THROUGH SAT. CONTINUED TO HAVE
CHANCES FOR THUNDERSTORMS LATE FRI INTO SAT NIGHT WHEN SOME ELEVATED
INSTABILITY IS EXPECTED...NO SEVERE WEATHER IS EXPECTED THOUGH.
850MB TEMPS WILL TOP OUT AROUND 15C FRI NIGHT INTO SAT...RESULTING
IN HIGH TEMPS IN THE MID 60S TO LOW 70S /WHICH IS AROUND AVERAGE/.
THE AIRMASS WILL BE COLDER SUN THROUGH TUE UNDER STRONGER NW FLOW
ALONG AND INCOMING SFC HIGH PRESSURE...RESULTING IN COOLER AND DRIER
CONDITIONS MON AND TUE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 721 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW TONIGHT AS LOW LEVELS
REMAIN DRY. COLD FRONT CURRENTLY OVER ONTARIO WILL DROP S INTO
PORTIONS OF NRN UPPER MI TONIGHT BEFORE STALLING AS SUBTLE SFC LOW
PRES DEVELOPS AND TRACKS ESE ALONG FRONT TOWARD THE UPPER GREAT
LAKES. IT IS EXPECTED THAT LOW CLOUDS AND BAND OF RAIN THAT WILL
DEVELOP N OF FRONT WILL PASS JUST N OF KCMX LATE TONIGHT. AS THE
VERY WEAK SFC LOW PASSES WED MORNING...COLD FRONT WILL PUSH
S...BRINGING LOW MVFR CIGS TO ALL TERMINALS. IFR NOT OUT OF THE
QUESTION AT KCMX AND ESPECIALLY KSAW WHICH WILL SEE A MORE DIRECT
UPSLOPE WIND AFTER FROPA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT WED SEP 17 2014
EXPECT WINDS GENERALLY 10-20KT AS THE FRONT STALLS OVER THE LAKE
EARLY THIS MORNING. FRONT WILL GET A PUSH S LATE THIS MORNING INTO
THE AFTERNOON WITH NE WINDS BEHIND THE FRONT INCREASING TO 15-25KT FOR
AT LEAST A TIME. OVER FAR WRN LAKE SUPERIOR...COASTAL
CONVERGENCE/FUNNELING MAY RESULT IN WINDS BRIEFLY AS HIGH AS 30KT.
WINDS WILL THEN DIMINISH TO UNDER 20KT TONIGHT/THU AS HIGH PRES
SETTLES OVER NRN ONTARIO IN THE VCNTY OF LAKE SUPERIOR. AS THE HIGH
THEN SHIFTS TOWARD NEW ENGLAND AND A LOW PRES TROF APPROACHES FROM
THE W...S WINDS WILL INCREASE THU NIGHT/FRI. WITH S WINDS A MORE
FAVORABLE DIRECTION FOR STRONGER WINDS OVER ERN LAKE SUPERIOR THAN
OVER THE W...WINDS SHOULD REACH 20-30KT OVER THE ERN LAKE ON FRI.
ALTHOUGH WINDS WILL DIMINISH ON SAT AS THE TROF ARRIVES OVER THE
UPPER LAKES...W TO NW WINDS WILL AGAIN INCREASE TO AS HIGH AS
20-30KT BEHIND THE TROF SAT NIGHT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ003-005>007-012>014-085.
FREEZE WARNING FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 10 AM
EDT /9 AM CDT/ THURSDAY 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
304 AM EDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 409 PM EDT TUE SEP 16 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A RIDGE OVER WRN NAMERICA
AND A TROF OVER ERN NAMERICA. IN THE TROF...ONE SHORTWAVE IS MOVING
E OF JAMES BAY WITH SECOND JUST UPSTREAM IN FAR NRN ONTARIO. NW FLOW
ACROSS CNTRL CANADA IS SENDING THE NEXT SHORTWAVE SE INTO NRN
SASKATCHEWAN/NRN MANITOBA. AT THE SFC...COLD FRONT ASSOCIATED WITH
THE FIRST SHORTWAVE EXTENDS FROM SRN JAMES BAY TO JUST N OF LAKE
SUPERIOR TO FAR SRN MANITOBA. REGIONAL RADAR DISPLAY HAS SHOWN -SHRA
IN THE VCNTY OF THE COLD FRONT WITH PCPN AS FAR S AS NRN LAKE
SUPERIOR. PCPN HAS BEEN WEAKENING/DISSIPATING OVER THE LAST FEW HRS.
OVER UPPER MI...MOSTLY SUNNY SKIES HAVE ALLOWED TEMPS TO RISE TO 60
TO 70 THIS AFTN.
WHILE COLD FRONT TO THE N WILL CONTINUE TO DRIFT S AND THEN STALL
TONIGHT...IT WILL BE THE THIRD IN THE AFORMENTIONED TRIO OF
SHORTWAVES THAT WILL HELP PROPEL IT S THRU THE AREA ON WED. IN
RESPONSE TO THAT THIRD SHORTWAVE AND UNDER THE RIGHT ENTRANCE OF
UPPER JET OVER NRN ONTARIO/QUEBEC...A SUBTLE SFC WAVE IS ALSO
EXPECTED TO DEVELOP ALONG THE COLD FRONT AND TRACK ACROSS SOUTHERN
LAKE SUPERIOR OR UPPER MI VERY LATE TONIGHT THRU WED MORNING. A NICE
CORRESPONDING RIBBON OF LOW-LEVEL FRONTOGENESIS ALSO DEVELOPS.
SO...MODELS LOOK ON TRACK IN GENERATING A BAND OF -SHRA N OF COLD
FRONT AND PATH OF WEAK SFC WAVE TONIGHT/WED. UTILIZED A CONSENSUS OF
MODEL GUIDANCE IN PARTICULAR HIGHER RES MODELS TO CONSTRUCT PCPN
FCST FOR TONIGHT/WED IN ORDER TO MINIMIZE SLIGHT DIFFERENCES NOTED
IN COLD FRONT WHICH AFFECTS PCPN PLACEMENT. BASED ON LOCATION OF THE
STREAK OF FRONTOGENESIS...EXPECT MOST OF THE -SHRA TO PASS JUST N
AND E OF UPPER MI VERY LATE TONIGHT AND WED MORNING. SO...CHC POPS
WERE PAINTED ACROSS THE KEWEENAW AND ERN FCST AREA. OTHERWISE...
NOTHING MORE THAN SCHC POPS WERE USED.
TEMPS WED ARE TRICKY AS THERE WILL BE AN OPPORTUNITY FOR SOME
WARMING BEFORE FROPA. ACROSS THE N...FRONT SHOULD PASS EARLY ENOUGH
TO LIMIT MUCH WARMING. HIGHS OVER THE N SHOULD RANGE FROM THE UPPER
40S ACROSS THE TIP OF THE KEWEENAW TO MID 50S ELSEWHERE. AFTER
FROPA...TEMPS ACROSS THE N WILL LIKELY FALL INTO THE 40S IN THE
AFTN UNDER A BRISK NRLY WIND AND STRATUS DECK FOLLOWING FROPA.
ACROSS THE S...NUDGED HIGH TEMPS UP...TO AS HIGH AS THE UPPER 60S
FAR SCNTRL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM EDT WED SEP 17 2014
NOT MUCH CHANGE IN THINKING FROM PREVIOUS SHIFT. THU WILL START WITH
LINGERING COLD AND FROST FROM WED NIGHT AS A 1025MB SFC HIGH WILL BE
CENTERED JUST NE OF THE CWA AT 12Z THU. THE HIGH WILL MOVE TO NEW
ENGLAND...WHILE STRENGTHENING TO 1030MB...BY 12Z FRI WHILE A SFC
TROUGH MOVES TO THE DAKOTAS. RETURN FLOW/WAA WILL JUST BE STARTING
LATE THU...SO DRY AIR LINGERING OVER THE REGION WILL MAKE FOR MOSTLY
SUNNY SKIES ON THU. TEMPS ON THU WILL TOP OUT IN THE MID TO UPPER
50S.
MOISTURE BEGINS TO INCREASE THU NIGHT AS THE RETURN FLOW
INCREASES...BUT MOST PRECIP LOOKS TO HOLD OFF UNTIL FRI WHEN AMPLE
MOISTURE WILL BE ESTABLISHED...A SERIES OF SHORTWAVE TROUGHS BEGINS
A TREK ACROSS THE AREA...AND THE PRESSURE GRADIENT/RETURN FLOW
INCREASES. MODELS ARE IN GOOD AGREEMENT ON THE START TIME OF PRECIP
FRI IN THE WAA REGIME...BUT HOW THINGS SHAPE UP ON FRIDAY AND
ESPECIALLY THE END TIME OF PRECIP ON SAT NIGHT OR SUN IS MORE
UNCERTAIN. EVEN THOUGH MODELS AGREE THAT THE STRONGEST SHORTWAVE
WILL ENTER THE REGION LATE SAT INTO SAT NIGHT...MODELS DISAGREE WITH
EACH OTHER AND FROM RUN TO RUN DUE TO THE COMPLEX NATURE OF PHASING
THE THREE WAVES OVER THE AREA. WILL LIKELY NOT HAVE GREATER
CERTAINTY ON END TIME OF PRECIP UNTIL CLOSER TO THE WEEKEND. HAVE
THE GREATEST POPS FROM LATE FRI THROUGH SAT. CONTINUED TO HAVE
CHANCES FOR THUNDERSTORMS LATE FRI INTO SAT NIGHT WHEN SOME ELEVATED
INSTABILITY IS EXPECTED...NO SEVERE WEATHER IS EXPECTED THOUGH.
850MB TEMPS WILL TOP OUT AROUND 15C FRI NIGHT INTO SAT...RESULTING
IN HIGH TEMPS IN THE MID 60S TO LOW 70S /WHICH IS AROUND AVERAGE/.
THE AIRMASS WILL BE COLDER SUN THROUGH TUE UNDER STRONGER NW FLOW
ALONG AND INCOMING SFC HIGH PRESSURE...RESULTING IN COOLER AND DRIER
CONDITIONS MON AND TUE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 721 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW TONIGHT AS LOW LEVELS
REMAIN DRY. COLD FRONT CURRENTLY OVER ONTARIO WILL DROP S INTO
PORTIONS OF NRN UPPER MI TONIGHT BEFORE STALLING AS SUBTLE SFC LOW
PRES DEVELOPS AND TRACKS ESE ALONG FRONT TOWARD THE UPPER GREAT
LAKES. IT IS EXPECTED THAT LOW CLOUDS AND BAND OF RAIN THAT WILL
DEVELOP N OF FRONT WILL PASS JUST N OF KCMX LATE TONIGHT. AS THE
VERY WEAK SFC LOW PASSES WED MORNING...COLD FRONT WILL PUSH
S...BRINGING LOW MVFR CIGS TO ALL TERMINALS. IFR NOT OUT OF THE
QUESTION AT KCMX AND ESPECIALLY KSAW WHICH WILL SEE A MORE DIRECT
UPSLOPE WIND AFTER FROPA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT TUE SEP 16 2014
AHEAD OF AN APPROACHING COLD FRONT FROM THE N...SW WINDS AS HIGH AS
15-25KT THIS EVENING WILL FALL BACK TO GENERALLY 10-20KT TONIGHT AS
THE FRONT STALLS OVER THE AREA. FRONT WILL GET A PUSH S ON WED...AND
NE WINDS BEHIND THE FRONT WILL INCREASE TO 15-25KT FOR AT LEAST A
TIME. OVER FAR WRN LAKE SUPERIOR...COASTAL CONVERGENCE/FUNNELING
WILL PROBABLY RESULT IN WINDS AS HIGH AS 30KT LOCALLY. WINDS WILL
THEN DIMINISH TO UNDER 20KT WED NIGHT/THU AS HIGH PRES SETTLES OVER
NRN ONTARIO IN THE VCNTY OF LAKE SUPERIOR. AS THE HIGH THEN SHIFTS
TOWARD NEW ENGLAND AND A LOW PRES TROF APPROACHES FROM THE W...S
WINDS WILL INCREASE THU NIGHT/FRI. WITH S WINDS A MORE FAVORABLE
DIRECTION FOR STRONGER WINDS OVER ERN LAKE SUPERIOR THAN OVER THE
W...WINDS SHOULD REACH 20-30KT OVER THE ERN LAKE ON FRI. ALTHOUGH
WINDS WILL DIMINISH ON SAT AS THE TROF ARRIVES OVER THE UPPER
LAKES...W TO NW WINDS WILL AGAIN INCREASE TO AS HIGH AS 20-30KT
BEHIND THE TROF SAT NIGHT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ003-005>007-012>014-085.
FREEZE WARNING FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
135 AM CDT Wed Sep 17 2014
.UPDATE:
Issued at 129 AM CDT Wed Sep 17 2014
Based on latest vsby trends of surface obs as well as HRRR and
lamp guidance will be going out with a dense fog advisory for our
eastern counties shortly...until 10am. It`s possible we may need
to expand a bit west and north in a few hours, and will at least
mention patchy fog as far west as eastern MO. However, upstream
clouds heading our direction should limit threat of widespread
dense fog, especially west of the Mississippi River.
Truett
&&
.SHORT TERM: (Through Tonight)
Issued at 230 PM CDT Tue Sep 16 2014
A weak s/w will approach the CWA late tonight bringing a chance
for storms to wrn and srn portions of the CWA late tonight.
Otherwise, expect clouds to continue to break up during the
afternoon and into the evening. Clouds are expected to build into
the region from the W tonight ahead of the s/w. Have trended twd
a compromise of guidance for wrn portions of the CWA and twd the
cooler guidance for ern portions. Latest guidance suggests FG will
develop late tonight impacting srn and ern portions of the CWA
where radiational cooling will be greatest.
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 309 PM CDT Tue Sep 16 2014
(Wednesday through Friday)
Main concern continues to be rain chances tomorrow into tomorrow
night over mainly central and southeast Missouri. GFS/NAM/ECMWF are
still in relatively good agreement in dropping a weak shortwave
trough across Missouri during the day tomorrow. Each of these
models shows some weak low level moisture lingering across central
and southeast Missouri into Wednesday night, so will continue a
chance of showers and thunderstorms in this area. This scenario is
depicted pretty well at least through 00Z by the reflectivity on the
NSSL WRF. Thereafter will maintain a dry forecast Thursday and
Friday as a surface ridge moves across the area at the same time a
upper ridge builds in from the west.
Went on the cooler side of guidance for highs the next couple of
days given the easterly surface flow and it matches up better with
mixing down the 900mb temperatures. Likewise followed the cooler
NAM MOS for lows.
(Saturday through next Tuesday)
While there is still some disagreement between the GFS/ECMWF
regarding the speed and depth of a trough that will pass through the
area this weekend, it still appears that the attendant cold front
will move through on Saturday night and early Sunday. Will keep
chances of showers and thunderstorms going Saturday into Sunday.
Will keep Monday and Tuesday dry at this point as we will be on the
back side of the the upper trough, though the latest runs of the GFS
is showing a secondary through dropping down in the northwesterly
flow on Tuesday. This is a new trend that the ECMWF is not
showing. Still expect at or just above normal temperatures ahead of
the front on Saturday before they drop back below normal for early
next week given expected 850mb temperatures in the 6-9C
range.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1104 PM CDT Tue Sep 16 2014
Northwest flow aloft will keep the mid Fall like conditions in
place. Upper air wave will move through overnight to reinforce the
northwest flow. Models trying to generate precitation at the nose
of a low level (5000 ft) jet of 30 knots over the MO/KS border. So
far no sign of anything develping. COU looks to be the only
location with a shot at rain, but will keep them dry for now. Band
of 4k to 5k clouds rapidly advancing SE. That may put a stop to
any MVFR ceilings. Lower clouds over southern MO are slowly
expanding a bit to the north. Some fog at SUS and CPS will will
bring temporary MVFR conditions until the clouds arrive. Wednesday
looks to be VFR.
Specifics for KSTL: 4k to 5k deck should arrive from 08 to 09z.
Will go with that and hold off on any MVFR ceilings. Lower clouds
over south central MO may work their way north and the MAV
guiidance brings them in for a short time. Not that confident they
will arrive, so will leave out for now.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...DENSE FOG ADVISORY until 10 AM CDT this morning FOR Bond IL-
Clinton IL-Fayette IL-Marion IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1116 PM CDT Tue Sep 16 2014
.UPDATE:
Issued at 845 PM CDT Tue Sep 16 2014
Going forecast looks on track this evening. Sky is clear/mostly
clear across the area with just a bit of cloud cover hanging in
across our SE MO counties. Short range guidance continues to show
an increasing amount of low level moisture convergence over
eastern Kansas/western Missouri this evening with convection
breaking out between 06Z-08Z. Models are pretty consistent in
keeping all but perhaps a few showers out of our area through 12Z
with the lion`s share of the precip back over southwest Missouri.
Should see scattered showers and thunderstorms spread into parts
of central and eastern Missouri later Wednesday morning. RAP and
HRRR seem to want to bring some showers into northeast Missouri by
15Z as well...and I may tweak the PoPs up before sending out the
midnight update if the new 00Z NAM and GFS agree.
Carney
&&
.SHORT TERM: (Through Tonight)
Issued at 230 PM CDT Tue Sep 16 2014
A weak s/w will approach the CWA late tonight bringing a chance
for storms to wrn and srn portions of the CWA late tonight.
Otherwise, expect clouds to continue to break up during the
afternoon and into the evening. Clouds are expected to build into
the region from the W tonight ahead of the s/w. Have trended twd
a compromise of guidance for wrn portions of the CWA and twd the
cooler guidance for ern portions. Latest guidance suggests FG will
develop late tonight impacting srn and ern portions of the CWA
where radiational cooling will be greatest.
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 309 PM CDT Tue Sep 16 2014
(Wednesday through Friday)
Main concern continues to be rain chances tomorrow into tomorrow
night over mainly central and southeast Missouri. GFS/NAM/ECMWF are
still in relatively good agreement in dropping a weak shortwave
trough across Missouri during the day tomorrow. Each of these
models shows some weak low level moisture lingering across central
and southeast Missouri into Wednesday night, so will continue a
chance of showers and thunderstorms in this area. This scenario is
depicted pretty well at least through 00Z by the reflectivity on the
NSSL WRF. Thereafter will maintain a dry forecast Thursday and
Friday as a surface ridge moves across the area at the same time a
upper ridge builds in from the west.
Went on the cooler side of guidance for highs the next couple of
days given the easterly surface flow and it matches up better with
mixing down the 900mb temperatures. Likewise followed the cooler
NAM MOS for lows.
(Saturday through next Tuesday)
While there is still some disagreement between the GFS/ECMWF
regarding the speed and depth of a trough that will pass through the
area this weekend, it still appears that the attendant cold front
will move through on Saturday night and early Sunday. Will keep
chances of showers and thunderstorms going Saturday into Sunday.
Will keep Monday and Tuesday dry at this point as we will be on the
back side of the the upper trough, though the latest runs of the GFS
is showing a secondary through dropping down in the northwesterly
flow on Tuesday. This is a new trend that the ECMWF is not
showing. Still expect at or just above normal temperatures ahead of
the front on Saturday before they drop back below normal for early
next week given expected 850mb temperatures in the 6-9C
range.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1104 PM CDT Tue Sep 16 2014
Northwest flow aloft will keep the mid Fall like conditions in
place. Upper air wave will move through overnight to reinforce the
northwest flow. Models trying to generate precitation at the nose
of a low level (5000 ft) jet of 30 knots over the MO/KS border. So
far no sign of anything develping. COU looks to be the only
location with a shot at rain, but will keep them dry for now. Band
of 4k to 5k clouds rapidly advancing SE. That may put a stop to
any MVFR ceilings. Lower clouds over southern MO are slowly
expanding a bit to the north. Some fog at SUS and CPS will will
bring temporary MVFR conditions until the clouds arrive. Wednesday
looks to be VFR.
Specifics for KSTL: 4k to 5k deck should arrive from 08 to 09z.
Will go with that and hold off on any MVFR ceilings. Lower clouds
over south central MO may work their way north and the MAV
guiidance brings them in for a short time. Not that confident they
will arrive, so will leave out for now.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
446 AM CDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM CDT WED SEP 17 2014
THE MAIN FORECAST ISSUES DURING THESE NEXT 24 HOURS CONSIST
OF...FIRSTLY: WHETHER OR NOT POTENTIALLY IMPACTFUL FOG WILL YET
DEVELOP THIS MORNING AND IF SO...WILL IT REMAIN MOSTLY HIT-AND-
MISS OR BECOME MORE WIDESPREAD IN SOME AREAS. SECONDLY: WILL AT
LEAST ISOLATED THUNDERSTORMS FLARE UP THIS EVENING AND ESPECIALLY
LATE TONIGHT...AND IF SO COULD A FEW EVEN BECOME STRONG TO
MARGINALLY SEVERE. THIRDLY: ALTHOUGH STEADIER SURFACE BREEZES
SHOULD ACT AGAINST FOG FORMATION A BIT MORE SO ON WEDNESDAY NIGHT
VERSUS THIS MORNING...AT LEAST PATCHY DEVELOPMENT AGAIN APPEARS
POSSIBLE AS LOW LEVEL MOISTURE AGAIN KICKS UP ANOTHER NOTCH.
TEMP-WISE...ASSUMING NO UNEXPECTED ENHANCED CLOUD ISSUES...BY FAR
THE BIG STORY IS THAT HIGHS TODAY ARE FORECAST TO BREACH THE 80+
MARK NEARLY CWA-WIDE...IN MANY PLACES FOR THE FIRST TIME IN 9
DAYS SINCE SEP. 8TH...A PRETTY NOTABLE STRETCH CONSIDERING MOST OF
IT OCCURRED DURING THE FIRST HALF OF SEPTEMBER.
STARTING WITH THE HERE AND NOW AS OF 0830Z/330 AM...OVERALL
ANOTHER VERY QUIET NIGHT ACROSS THE CWA...AS ANY WINDOW OF
OPPORTUNITY FOR ELEVATED CONVECTION IN SOUTHEAST ZONES HAS ALL
BUT PASSED BY...AS SEVERAL MODELS CORRECTLY SUGGESTED THAT THIS
ACTIVITY WOULD INITIATE AND FOCUS AT LEAST A FEW COUNTIES OUTSIDE
THE AREA OVER EASTERN KS/WESTERN MO AND THIS IN FACT HAS BEEN THE
CASE. MEANWHILE...11-3.9 MICRON SATELLITE IMAGERY REVEALS NEARLY
CLOUD-FREE SKIES OVER THE CWA...ALTHOUGH A RECENTLY FORMED RIBBON
OF LOW STRATUS RACING NORTH OUT OF CENTRAL KS TOWARD SOUTHEAST NEB
APPEARS POISED TO POSSIBLY BARELY BRUSH OUR EXTREME SOUTHEAST
ZONES AS IT TRACKS NORTH-NORTHEAST. AT THE SURFACE...A RATHER
DISORGANIZED VERY LIGHT/VARIABLE WIND REGIME IS IN PLACE OVER THE
CWA...AS THE LOCAL AREA LIES WELL TO THE WEST OF THE PRIMARY RIDGE
AXIS OVER THE IL/IN AREA...AND JUST TO THE NORTH OF A VERY WEAK
LOW AND TROUGH AXIS OVER SOUTHWEST KS. AS SUSPECTED 24 HOURS
AGO...THE COMBO OF MAINLY CLEAR SKIES/LIGHT BREEZES HAS FOSTERED
AT LEAST SOME LIMITED FOG DEVELOPMENT...BUT BASED ON AUTOMATED
AIRPORT OBS AT LEAST SO FAR ANY FOG HAS BEEN PRETTY HIT AND MISS
IN NATURE AND LIKELY FAVORING TYPICAL LOW LYING AREAS VERSUS MORE
WIDESPREAD. THAT BEING SAID...A FEW AUTOMATED WITHIN OR VERY NEAR
THE CWA HAVE AT LEAST BRIEFLY REPORTED VISIBILITY UNDER 1
MILE...INCLUDING A LOCALIZED QUARTER MILE AT ORD. AS FOR LOW TEMPS
THIS MORNING...PARTS OF ESPECIALLY THE NORTHWEST HALF OF THE CWA
ARE HEADING TOWARD LOWS A FEW DEGREES COOLER THAN EXPECTED AS A
FEW SPOTS HAVE EVEN DIPPED INTO THE UPPER 40S...WHILE MUCH OF THE
SOUTHEAST HALF OF THE CWA SHOULD BOTTOM OUT LOW-MID 50S AND EVEN
CLOSER TO 60 FAR SOUTH. IN THE MID-UPPER LEVEL PICTURE...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM FAIRLY STEADY-
STATE NORTHWESTERLY FLOW OVER THE CENTRAL PLAINS...DIRECTED
BETWEEN A LARGE SCALE WESTERN CONUS RIDGE AND EASTERN CANADA
TROUGH. WELL TO THE SOUTHWEST...WEAKENING TROPICAL STORM ODILE IS
IN THE PROCESS OF SHIFTING OUT OF THE BAJA AREA TOWARD SOUTHERN
AZ. CLOSER TO HOME...A LOW AMPLITUDE DISTURBANCE ZIPPING SOUTHEAST
OVER THE NEB/IA/SD BORDER AREA TOWARD NORTHERN MO HAS HELPED
STRENGTHEN A WEST-SOUTHWESTERLY LOW LEVEL JET MAINLY OVER
KS...AND ITS NO COINCIDENCE THAT ITS EXIT REGION INTO THE KS/MO
BORDER REGION IS WHERE THE INCREASINGLY ACTIVE BAND OF MORNING
ELEVATED CONVECTION HAS FIRED UP.
LOOKING AHEAD AND NOW AND STARTING WITH THESE NEXT FEW HOURS
THROUGH AROUND SUNRISE...OBVIOUSLY FOG TRENDS ARE THE MAIN
CONCERN. ALTHOUGH FOG IS OFTEN A VERY FICKLE ENTITY...VERY SHORT
TERM VISIBILITY PROGS FROM THE RAP13 AND HRRR SUGGEST THAT THINGS
COULD CERTAINLY WORSEN/BECOME MORE WIDESPREAD YET THIS MORNING
PRIMARILY IN WESTERN AND SOUTHERN PORTIONS OF THE CWA...BUT MAYBE
ON A LOCALIZED BASIS ALMOST ANYWHERE. THINGS WOULD HAVE TO GET
CONSIDERABLE WORSE/WIDESPREAD TO EVEN BEGIN TO CONSIDER ANY KIND
OF FORMAL ADVISORY...BUT IT WILL LIKELY BE AT LEAST 14-15Z/9-10AM
BEFORE WE ARE COMPLETELY OUT OF THE WOODS ON SOME AREAS SEEING
VISIBILITIES NEAR/BELOW 1 MILE AND LOCALLY DENSE. THE BOTTOM LINE:
A MIX OF PATCHY FOG AND AREAS-OF FOG WORDING REMAINS IN THE
FORECAST FOR A FEW HOURS PAST SUNRISE...AND THESE TRENDS WILL BE
CLOSELY MONITORED.
GETTING BEYOND ANY MORNING FOG CONCERNS TO THE HEART OF THE
DAYTIME PERIOD...THE MAIN THEME HERE IS DRY CONDITIONS PERSISTING
IN THE PRESENCE OF NOTABLY WARMER CONDITIONS THAN OBSERVED LATELY.
IN THE MID-UPPER LEVELS...FAIRLY CONSISTENT AND LARGELY UNEVENTFUL
NORTHWESTERLY FLOW WILL CONTINUE OVER THE CENTRAL PLAINS AS THE
AFOREMENTIONED SUBTLE DISTURBANCE CURRENTLY JUST NORTHEAST OF THE
CWA DEPARTS WELL SOUTHEAST INTO THE OH VALLEY AREA BY DAYS END.
GIVEN THE LACK OF PERCEPTIBLE FORCING...CONFIDENCE IS RATHER HIGH
IN A DRY-DAY CWA-WIDE AS NEARLY ALL MODEL QPF AND REFLECTIVITY
FIELDS SUGGEST...AS ANY APPRECIABLE CONVECTIVE INSTABILITY THAT
MIGHT MANAGE TO BUILD SHOULD REMAIN CAPPED PER NAM FORECAST
SOUNDINGS. AT THE SURFACE...THE VERY LIGHT/VARIABLE BREEZES OF
THIS MORNING SHOULD GRADUALLY GIVE WAY TO PREVAILING EAST-
SOUTHEAST WINDS ONLY AROUND 10 MPH IN RESPONSE TO WEAK HIGH PLAINS
PRESSURE FALLS TO THE WEST. ONCE ANY MORNING LOWER STRATUS/FOG
THAT DEVELOPS BURNS OFF...SKIES SHOULD AVERAGE NO WORSE THAN
PARTLY CLOUDY DESPITE A FEW PASSING BATCHES OF MID-HIGH
CLOUDS...IN OTHER WORDS NO PESKY LOWER DAYTIME STRATUS DECK
ENVELOPING MUCH OF THE CWA DURING PEAK HEATING AS DID IN FACT
OCCUR YESTERDAY. THE OBVIOUS RESULT SHOULD BE A NOTICEABLE RISE
IN TEMPS VERSUS LATELY. THAT BEING SAID...DID NUDGE HIGHS DOWN
1-2 DEGREES FROM PREVIOUS FCST MAINLY ACROSS THE SOUTHERN CWA
WHILE LEAVING MUCH OF THE NORTH UNCHANGED. THE NET RESULT IS LOW
80S ACROSS MOST CENTRAL/NORTHEAST ZONES AND MAINLY MID 80S
SOUTHWEST WITH UPPER 80S MOST FAVORED IN FAR SOUTHWEST COUNTIES
SUCH AS ROOKS. THE AIRMASS WILL ALSO GET ANOTHER BOOST IN THE
HUMIDITY DEPARTMENT AS DEWPOINTS RISE INTO AT LEAST THE LOW 60S
MOST AREAS FOR THIS AFTERNOON.
TURNING TO THIS EVENING TONIGHT...THE BEST WAY TO DESCRIBE THINGS
IS THAT IT COULD BE A FAIRLY ACTIVE NIGHT IN PARTS OF THE CWA WITH
AT LEAST LIMITED STRONG THUNDERSTORM DEVELOPMENT AND AT LEAST
LIMITED FOG DEVELOPMENT...OR IT COULD ALMOST JUST AS EASILY BE
ANOTHER FAIRLY UNEVENTFUL NIGHT. SUCH IS THE FICKLE NATURE OF
NORTHWESTERLY-FLOW-ALOFT SITUATIONS WHEN LARGE-SCALE FORCING
REMAINS WEAK. SPEAKING OF THE MID-UPPER LEVELS...THE NORTHWESTERLY
FLOW PERSISTS BUT ACTUALLY MIGHT WEAKEN VERY SLIGHTLY AS THE MAIN
RIDGE AXIS ALIGNED OVER THE ROCKIES EDGES EVER SO SLIGHTLY FARTHER
EAST. THERE WILL UNDOUBTEDLY BE AT LEAST 1 OR 2 VERY LOW AMPLITUDE
DISTURBANCES WORKING SOUTHEASTWARD OVER/NEAR THE CWA TONIGHT...AND
COMPARED TO THIS MORNING THIS TIME AROUND IT APPEARS THERE WILL BE
MORE PRONOUNCED LOW-MID LEVEL CONVERGENCE OVER ESPECIALLY THE
SOUTHWESTERN 1/2 OF THE CWA TONIGHT AS NOTED IN 315K ISENTROPIC
SURFACE FORECASTS AND ALSO NOTED IN THE MORE WESTERLY FLOW AND
RESULTANT ELEVATED THETA-E ADVECTION BASED MAINLY IN THE 800-700MB
LAYER. PER VARIOUS DETERMINISTIC AND HIGHER-RES REFLECTIVITY MODEL
SOLUTIONS...AT LEAST A FEW THUNDERSTORMS ARE EXPECTED TO FLARE UP
ALONG THIS ELEVATED CONVERGENCE ZONE...WITH THE GREATEST
LIKELIHOOD WITHIN THE SOUTHWESTERN 1/2 OF THE CWA AFTER MIDNIGHT.
THAT BEING SAID...STORMS CANNOT BE COMPLETELY BE RULED OUT BEFORE
MIDNIGHT EITHER AND HAVE MAINTAINED SOME 20 POPS IN SOUTHWESTERN
AREAS DURING THE EVENING WHILE EXPANDING AT LEAST 20 POPS TO ALL
AREAS AFTER MIDNIGHT BUT FOCUSING HIGHEST 30S IN SOUTHERN ZONES.
SHOULD CONVECTION MATERIALIZE...CERTAINLY A FEW STRONG STORMS
CAPABLE OF PRODUCING HAIL TO AT LEAST NICKEL SIZE OR SLIGHTLY
LARGER CANNOT BE RULED OUT GIVEN ELEVATED CAPE OF 1000-1500 J/KG
IN THE PRESENCE OF AROUND 40KT OF DEEP LAYER SHEAR. MEANWHILE AT
THE SURFACE...FAIRLY LIGHT BUT STEADY EASTERLY BREEZES GENERALLY
5-10 MPH SHOULD PERSIST OVERNIGHT...WHICH SHOULD HELP WORK AGAINST
ANY WIDESPREAD/IMPACTFUL FOG FORMATION...ALONG WITH OF COURSE ANY
LOCALIZED MIXING FROM CONVECTIVE ACTIVITY. THAT BEING SAID...AT
LEAST PATCHY LIGHT FOG CERTAINLY CANNOT BE RULED OUT IN THE MOIST
EASTERLY FLOW...SO HAVE INTRODUCED PATCHY FOG TO THE LATE NIGHT
FORECAST. THE EARLIER 00Z NAM SUGGESTED THAT POTENTIALLY
WIDESPREAD LOW STRATUS AND POSSIBLE LIGHT DRIZZLE COULD
MATERIALIZE AS WELL...BUT THE LATEST 06Z NAM SUGGESTS THAT LOW
LEVEL MOISTURE DEPTH WILL LIKELY REMAIN INSUFFICIENT FOR DRIZZLE
PRODUCTION. MADE VERY LITTLE ALTERATION TO LOW TEMPERATURES...AS
ANOTHER UPWARD CLIMB FROM ONE NIGHT TO THE NEXT CONTINUES...WITH
LOWS AIMED FROM THE UPPER 50S NORTH...LOW 60S CENTRAL AND MID 60S
SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED SEP 17 2014
SUMMARY...FRIDAY...WITH HIGHS IN THE MID 80S...STILL APPEARS TO THE
BE THE WARMEST DAY OF THE NEXT 7 DAYS FOR MOST AREAS...ALTHOUGH IT
WILL NOT BE ALL THAT MUCH WARMER THAN TODAY. RAIN CHANCES IN THE
EXTENDED PERIOD ARE NOT THAT GOOD AND CHANCES HAVE EVEN FALLEN OFF A
LITTLE BIT DURING THE PERIODS WHERE 24HRS EARLIER THEY LOOKING THE
BEST...FRIDAY NIGHT INTO SATURDAY. OVERALL IT WILL BE A FAIRLY
TYPICAL MID SEPTEMBER PERIOD WITH HIGHS ON MOST DAYS AVERAGING OUT
IN THE 70S TO AROUND 80.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES SHOULD DECREASE. THERE IS
WEAK ISENTROPIC LIFT IN THE LOWEST LAYER FROM AROUND AND BELOW 850
MB AND FORECAST MODELS INDICATE THAT A LOW STRATUS DECK COULD
PERSIST THROUGH MUCH OF THE DAY. INITIALLY THIS STRATUS DECK MAY BE
LOW ENOUGH TO BE FOG RIGHT AFTER SUNRISE. SOME FORECAST MODELS ARE
TRYING TO GENERATE A HUNDREDTH OR TWO OF SPLOTCHY QPF. TYPICALLY
THIS COULD BE SPRINKLES...DRIZZLE...OR EVEN ISOLATED THUNDERSTORMS.
IN THIS CASE THE FORECAST SOUNDINGS INDICATE THAT THE SATURATED
STRATUS DECK WILL BE BELOW 850 MB AND NOT THICK ENOUGH TO PRODUCE
DRIZZLE. THERE COULD BE SOME CLOUD SEEDING FROM PASSING MID CLOUDS
GENERATING A FEW SPRINKLES...BUT MOST AREAS WILL BE DRY. THERE IS
SOME WEAK INSTABILITY SO WE CAN NOT RULE OUT THUNDERSTORMS...BUT
ODDS OF THUNDER ARE LOW ENOUGH TO CONTINUE TO KEEP IT OUT OF THE
FORECAST FOR NOW. THE STRATUS DECK WILL KEEP TEMPERATURES DOWN
ESPECIALLY ACROSS NEBRASKA ZONES WHERE STRATUS WILL LIKELY LINGER
LONGER. HIGHS WILL RANGE FROM THE MID 70S IN THE TRI CITIES TO THE
MID 80S ACROSS OUR SOUTHWEST KANSAS COUNTIES.
THURSDAY NIGHT INTO FRIDAY AFTERNOON...THERE IS GOOD AGREEMENT IN
NUMEROUS FORECAST MODELS AND MODEL BLENDS THAT THIS WILL BE A DRY
PERIOD ACROSS OUR FORECAST AREA. THE REMNANTS OF HURRICANE ODILE WILL
BE HEADING NORTHEAST INTO THE TEXAS PANHANDLE AND POSSIBLY INTO FAR
SOUTHWEST KANSAS BY FRIDAY AFTERNOON...BUT STILL OUTSIDE OF OUR
FORECAST AREA. AN UPPER TROUGH COMING OUT OF THE NORTHERN STREAM
WILL BE BREAKING OFF A VORT MAX OVER CALIFORNIA RESULTING IN A LESS
VIGOROUS WAVE FOR OUR FORECAST AREA THAN WAS INDICATED IN MODEL RUNS
24HRS AGO.
FRIDAY NIGHT INTO SATURDAY...THE UPPER TROUGH SWINGING THROUGH THE
PLAINS IS LOOKING LESS IMPRESSIVE WITH RECENT FORECAST RUNS AS SOME
OF THE ENERGY IS BEING LEFT BEHIND OVER CALIFORNIA WHERE IT LEAVES
BEHIND A CUT OFF LOW. MODEL BLENDS HAVE REDUCED POPS SOME IN THIS
PERIOD...AND IT SEEMS JUSTIFIED GIVEN THE SYNOPTIC SITUATION. WILL
HAVE TO REALLY KEEP AN EYE ON THE REMNANTS OF ODILE DURING THIS
PERIOD AS THE REMAINING VORT MAX AND MOISTURE WILL BE COMING UP
THROUGH KANSAS AND MIGHT BE FAR ENOUGH NORTH TO IMPACT OUR CWA.
HOWEVER...THE BETTER BET AT THIS TIME FOR ODILE RELATED
MOISTURE/RAINFALL WILL BE JUST TO THE SOUTH OF OUR FORECAST AREA.
SUNDAY THROUGH TUESDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH GENERALLY DRY WEATHER LIKELY FOR OUR FORECAST
AREA. CAN NOT COMPLETELY RULE OUT A SHORT WAVE SLIDING DOWN INTO OUR
FORECAST AREA ON THE EAST SIDE OF THE RIDGE BY TUESDAY...BUT MOST
AREAS APPEAR DRY AT THIS TIME. HIGH TEMPERATURES WILL BE NEAR NORMAL
AVERAGING OUT IN THE 70S.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY)
ISSUED AT 100 AM CDT WED SEP 17 2014
CONFIDENCE IS FAIRLY HIGH IN PREVALENT VFR CEILING/VISIBILITY
THROUGH THE MAJORITY OF THE PERIOD...WITH THE MAIN ISSUE BEING THE
POSSIBILITY OF REDUCED VISIBILITY IN FOG DEVELOPMENT THIS MORNING
MAINLY WITHIN A FEW HOURS EITHER SIDE OF SUNRISE. OPTED TO REMAIN
QUITE CONSISTENT WITH PREVIOUS FORECAST IN DEPICTING A PERIOD OF
PREVAILING MVFR VISIBILITY AT BOTH SITES 10Z-14Z...BUT OF COURSE
THIS IS JUST A BEST STAB AT VISIBILITY...AS CONSIDERABLE
FLUCTUATION ON EITHER SIDE OF THIS RANGE (FROM VFR TO IFR OR
WORSE) CANNOT BE COMPLETELY RULED OUT. AT ANY RATE...ONCE ANY
POSSIBLE MORNING FOG VACATES EXPECT FAIRLY TRANQUIL AVIATION
CONDITIONS THROUGH THE REMAINDER OF THE PERIOD. ANOTHER ROUND OF
AT LEAST LIGHT FOG AND MAYBE SOME STRATUS WITH A HEIGHTENED RISK
FOR A LOW CEILING COULD MATERIALIZE SHORTLY BEYOND THE CURRENT
VALID PERIOD LATE WEDNESDAY NIGHT. AS FOR SHOWER/THUNDERSTORM
POTENTIAL...IT IS ESSENTIALLY NIL THROUGH THE FIRST 18 HOURS OR
SO...BUT THERE IS MAYBE A SMALL CHANCE AT PLAY DURING THE EVENING
HOURS. HOWEVER...THIS CHANCE APPEARS TOO SMALL TO JUSTIFY EVEN A
VICINITY (VCTS) MENTION AT THIS JUNCTURE. SURFACE BREEZES SHOULD
NOT BE MUCH OF AN ISSUE THROUGH THE PERIOD...WITH SUSTAINED SPEEDS
AVERAGING UNDER 10KT AND FROM AN EAST-SOUTHEAST DIRECTION AT MOST
TIMES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
334 AM CDT WED SEP 17 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM CDT WED SEP 17 2014
NORTHWESTERLY FLOW ALOFT CONTINUES OVER THE REGION THIS MORNING AS
AN UPPER LEVEL RIDGE AXIS EXTENDS ACROSS THE ROCKIES. TROPICAL STORM
ODILE CONTINUES TO MOVE ACROSS THE NORTHERN GULF OF CALIFORNIA AND
TOWARD THE SOUTHWESTERN UNITED STATES. AT THE SURFACE...HIGH
PRESSURE HAS MOVED INTO THE EASTERN CONUS WHILE A WARM FRONT
EXTENDS EAST ACROSS KANSAS FROM LOW PRESSURE CENTERED OVER
SOUTHEAST COLORADO/SOUTHWEST KANSAS. LOW LEVEL WARM AIR/THETA-E
ADVECTION TO OUR SOUTH HAS GENERATED ISOLATED SHOWERS AND
THUNDERSTORMS OVER NORTHEAST KANSAS SO WILL KEEP THE SMALL CHANCE
OVER OUR EXTREME SOUTHERN COUNTIES THROUGH THE EARLY MORNING
HOURS. AN AREA OF LOW CLOUDS THAT DEVELOPED LAST EVENING SHOULD
MIX OUT LATER THIS MORNING...ALLOWING SFC TEMPERATURES TO RISE
INTO THE UPPER 70S TO LOW 80S TODAY.
WE HAVE REMOVED THE SMALL POPS THAT HAD BEEN IN OUR SOUTHERN
COUNTIES FOR THIS EVENING DUE TO LACK OF ANY STRONG FORCING
MECHANISM. A MAJORITY OF MODEL SOLUTIONS MAINTAIN A DRY PERIOD
THIS AFTERNOON AND EVENING AS WELL. LOW LEVEL MOIST ADVECTION WILL
CONTINUE THROUGH THE OVERNIGHT HOWEVER. A FEW THUNDERSTORMS COULD
DEVELOP ACROSS NORTHEAST KANSAS NEAR 850MB FRONT AND SPREAD INTO
FAR SOUTHEAST NEBRASKA. WILL CARRY A SMALL POP IN OUR FAR
SOUTHWESTERN CWA AFTER 06Z. FORECAST SOUNDINGS DO INDICATE
POTENTIAL FOR DRIZZLE/FOG OVERNIGHT SO HAVE INCLUDED A MENTION AS
LOW LEVEL MOISTURE STREAMS NORTH.
CLOUDS LOOK SLOW TO MOVE OUT ON THURSDAY WHICH WOULD KEEP HIGHS
ABOUT 5 DEGREES COOLER THAN WEDNESDAY. STRONG LOW LEVEL WARM AIR
ADVECTION WILL CONTINUE INTO FRIDAY WHICH SHOULD BE OUR WARMEST DAY
OF THE FORECAST WITH HIGHS IN THE MID TO UPPER 80S. MOISTURE WILL
REMAIN IN PLACE AS WELL WITH SFC DEWPOINTS FORECAST AROUND 70.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 AM CDT WED SEP 17 2014
UPPER RIDGE WILL FLATTEN AND MOVE OVERHEAD WHILE A SHORTWAVE
TROUGH OVER THE NORTHERN PLAINS WILL ALLOW A WEAK COLD FRONT TO
DROP SOUTH INTO THE NORTHERN CWA AROUND 06Z/SAT. EARLIER THIS WEEK
WE WERE A BIT CONCERNED WITH THE AMOUNT OF MOISTURE TS ODILE WAS
GOING TO BRING TO THE FORECAST AREA BUT LATEST MODEL RUNS
CONTINUE TO SHOW THIS WILL MOVE JUST TO OUR SOUTH ACROSS KANSAS.
THE 00Z ECMWF WASHES THE COLD FRONT OUT OVER THE AREA WITH A LACK
OF UPPER LEVEL SUPPORT. THE 00Z GFS HOLDS ON TO A MORE DEFINED
COLD FRONT AND DROPS IT THROUGH THE CWA BY SATURDAY EVENING. IN
ANY CASE...THE FRONTAL BOUNDARY SEEMS TO BE SLOWED DOWN SOMEWHAT
FROM PREVIOUS RUNS SO THERE IS A BIT OF CONCERN FOR LINGERING
PCPN IN OUR SOUTHERN CWA SATURDAY EVENING.
THE REMAINDER OF THE FORECAST LOOKS DRY WITH SLIGHTLY BELOW NORMAL
TEMPERATURES INTO EARLY NEXT WEEK AS A DEEPENING TROUGH TO OUR
NORTHEAST DRAGS COOLER TEMPS INTO THE AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1134 PM CDT TUE SEP 16 2014
BKN-OVC CLOUD LAYER AROUND FL045 CONTINUES TO SLOWLY WORK
SOUTHEAST ACROSS EASTERN NEBRASKA AT THE START OF THE PERIOD.
BIG QUESTION IS WHETHER SKIES CLEAR OR SOME CLOUDS LINGER THROUGH
THE MORNING. RAP MAINTAINS 850MB RH OVER FAR EASTERN NEBRASKA
THROUGH SUNRISE SO IF THIS IS THE CASE FOG WILL BE LESS LIKELY.
OTHERWISE VFR CONDITIONS EXPECTED AFTER 15Z AT ALL SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1142 PM CDT TUE SEP 16 2014
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 300 PM CDT TUE SEP 16 2014
ALTHOUGH FORECAST CONCERNS ARE RELATIVELY MINOR IN THE SHORT
TERM...THERE ARE SEVERAL MOVING PARTS THAT COULD CREATE A
CHANGEABLE FORECAST.
FORECAST AREA WILL REMAIN IN NWRLY UPPER FLOW THROUGH LATE
THURSDAY BEFORE SHORTWAVE ENERGY FLATTENS UPPER RIDGE EWD ACROSS
THE FA. ANY UPPER WAVES IMPACTING THE AREA ARE WEAK AND ILL-
DEFINED...WITH LOW LEVEL THETA E ADVECTION PROBABLY PROVIDING MUCH
OF ANY LIFT ACROSS THE AREA. SOME OF THIS WARM ADVECTION ARRIVES
ACROSS MOSTLY SERN ZONES LATE TONIGHT AND THUS A SMALL TSTM
CHANCE WAS MAINTAINED GENERALLY S THRU SE OF LINCOLN. ALSO AN AREA
OF LOW CLOUDS...ROUGHLY MARKING THE EDGE OF THE H85 MOISTURE
RETURN...WILL BE SPREADING ACROSS THE FA EARLY AND MAY LIMIT FOG
REDEVELOPMENT. HOWEVER...WILL MENTION PATCHY FOG MAINLY SRN AREAS
OUTSIDE OF WHERE THUNDERSTORM CHANCES WILL BE CARRIED AS LOW/MID
50 DEWPTS SPREAD NE. CLOUDS SHOULD BRING MILDER LOWS TO THE FA
WITH LITTLE CHANGES. THE LOWER CLOUDS APPEAR TO MIX OUT ON
WEDNESDAY AND 12Z GFS/NAM/ECMWF POINT TO MAX TEMPS PERHAPS A
CATEGORY WARMER THAN EARLIER FORECAST AND THESE WERE RAISED TO
NEAR MET GUIDANCE. HEATING AND INCREASED MOISTURE/INSTABILITY
COULD ALLOW FOR LATE AFTN CONVECTION TO DEVELOP SWRN ZONES...WITH
SREF INCREASING RISK LAST FEW RUNS...AND A SMALL CHANCE WAS
INSERTED LATE WITH POPS CARRIED INTO WED NIGHT FAR S. WITH NW FLOW
ALOFT...A SMALL CONDITIONAL SEVERE THREAT DOES EXIST AS SHEAR IS A
LITTLE SUPPORTIVE.
AS H85/SFC DWPTS CONTINUING RISING INTO WED NIGHT LOW CLOUDS
AGAIN LOOK LIKELY BY THURSDAY MORNING. ALTHOUGH FOG AND DRIZZLE
ALSO POSSIBLE...WILL WAIT FOR ANOTHER MODEL RUN OR TWO TO ASSESS
DEPTH AND OTHER FACTORS. WITH INCREASING SERLY WINDS THU AFTN SOME
BREAKS EXPECTED...BUT POSSIBLY NOT QUICKLY ENOUGH TO ALLOW MAX
TEMPS TO GET AS WARM AS THOSE FORECAST FOR WED.
AS UPPER FLOW FLATTENS OVER THE FA TOWARD FRIDAY...LEFT IN SMALL
POPS NERN ZONES THU NGT AS LOW LEVEL JET STRENGTHENS AHEAD OF THIS
ALLOWING MORE UNSTABLE AIR TO SPREAD NE AS WELL. FRIDAY LOOKS LIKE
THE WARMEST DAY OF AT LEAST THE NEXT 7...WITH GOOD MIXING ON
MODERATELY STRONG SW WINDS. BOOSTED BOTH WINDS AND TEMPS A BIT.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE SEP 16 2014
LOOKS LIKE 12Z ECMWF TAKES REMNANTS OF TS ODILE THRU KS...
FOLLOWING LEAD OF FARTHER S GFS WHICH CONTINUED TO DO SO WITH 12Z
RUN. HOWEVER...SOME SUBTROPICAL MOISTURE ON ITS NORTH END COULD
STILL BE OVER THE FA AND WITH NRN STREAM WAVE DRIVING A COLD
FRONT ACROSS...HIGH CHANCE/LIKELY POPS WERE MAINTAINED SERN ZONES
ON SATURDAY. LINGERED SMALL POPS FAR SE SAT NIGHT...BUT COULD
VERY WELL SEE THE ACTIVITY SE OF THE FA BY THEN. REST OF THE
FORECAST WAS DRY.
WITH BULK OF MOISTURE FM ODILE POSSIBLY REMAINING TO OUR
SOUTH...AMOUNT OF PREFRONTAL CONVECTION AND/OR CLOUDS MAY BE
LACKING ENOUGH TO ALLOW MAX TEMPS ON SATURDAY TO APPROACH THOSE
OF FRIDAY...SPECLY CNTRL/SRN ZONES. BUT FOR NOW LEFT MODEL BLEND
ALONE WITH MOSTLY 70S FOR HIGHS. PLEASANT TEMPERATURES LOOK TO
PREVAIL SUNDAY-TUESDAY WITH GFS/ECMWF BLEND SUGGESTING LOWER-MID
70S FOR MAX TEMPS. ALTHOUGH COULD SEE THE NEED TO LOWER MAX/MINS
SOME IF TROUGH DEEPENING TO OUR EAST DOES SO A BIT FARTHER SW.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1134 PM CDT TUE SEP 16 2014
BKN-OVC CLOUD LAYER AROUND FL045 CONTINUES TO SLOWLY WORK
SOUTHEAST ACROSS EASTERN NEBRASKA AT THE START OF THE PERIOD.
BIG QUESTION IS WHETHER SKIES CLEAR OR SOME CLOUDS LINGER THROUGH
THE MORNING. RAP MAINTAINS 850MB RH OVER FAR EASTERN NEBRASKA
THROUGH SUNRISE SO IF THIS IS THE CASE FOG WILL BE LESS LIKELY.
OTHERWISE VFR CONDITIONS EXPECTED AFTER 15Z AT ALL SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
320 AM EDT WED SEP 17 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE EARLY THIS MORNING. HIGH PRESSURE
WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...PRECIPITATION ASSOCIATED WITH A COLD FRONT
DROPPING SOUTH ACROSS THE FORECAST AREA IS MOVING EAST AND
TRANSITIONING TO A MORE STRATIFORM EVENT AS THE ATMOSPHERE
CONTINUES TO STABILIZE. HOWEVER..THERE IS STILL SOME
SHOWER/THUNDERSTORM ACTIVITY AS AN UPPER DISTURBANCE IMPINGES UPON
THE AREA. THIS DISTURBANCE IS INDUCING CYCLOGENESIS ALONG THE
FRONT...LIKELY OVER OUR FAR WESTERN COUNTIES...WHERE THE STRONGEST
CONVECTION IS OCCURRING.
A CONSENSUS OF GUIDANCE JUMPS FRONT OFFSHORE AND SOUTH OF THE
EASTERN CAROLINAS BY DAYBREAK AS CYCLOGENESIS STRENGTHENS OFF THE
COAST. FOR THE REMAINDER OF THE DAY AND OVERNIGHT...THE COMBINATION
OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND LOW PRESSURE
OFFSHORE WILL BRING A SEASONALLY COOL EAST TO NORTHEASTERLY FLOW TO
THE AREA. HIGHS WILL RANGE FROM THE LOWER 80S UP NORTH TO THE MID
80S FURTHER SOUTH. WILL RETAIN THE LOW CHANCE OF CONVECTION TODAY
AND THIS EVENING AS MODEL SOUNDINGS INDICATE A MARGINALLY TO
MODERATELY UNSTABLE AIRMASS IN CONJUNCTION WITH A SERIES OF WEAK
UPPER IMPULSES DROPPING INTO THE BASE OF THE H/5 LONGWAVE TROUGH
LINGERING OVER EASTERN CONUS. A ADDITIONAL FACTOR FAVORING
PRECIPITATION TODAY WILL BE THE LOW LEVEL CONVERGENCE RESULTING FROM
WESTERLY WINDS ALOFT RIDING OVER EASTERLY WINDS BELOW.
OVERNIGHT LOWS WILL CONTINUE IN THE SEASONAL VEIN...WITH LOW RANGING
FROM THE LOWER 60S INLAND TO THE MID 60S CLOSER TO THE COAST AND
UPPER 60S AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SURFACE HIGH OVER THE GREAT LAKES THU WILL
SHIFT EAST TO NEW ENGLAND FRI...SETTING UP A CLASSIC WEDGE. LIGHT
NORTHEAST FLOW THU AND LIMITED LOW LEVEL MOISTURE MAY ALLOW FOR SOME
SUNSHINE BUT INCREASED NORTHEAST FLOW AND LOW LEVEL MOISTURE FRI
WILL LIKELY LEAD TO AN INCREASE IN CLOUD COVER. PRECIP CHANCES ARE
RATHER LIMITED EACH DAY WITH WEAK SUBSIDENCE ALOFT KEEPING THE MID
LEVELS DRY. THE ONLY REAL THREAT APPEARS TO BE ALONG THE IMMEDIATE
COAST WHERE LOW LEVEL MOISTURE IS HIGHEST...ESPECIALLY FRI...AND
SOME LIGHT RAIN COULD DEVELOP. MEASURABLE RAINFALL WILL BE DIFFICULT
TO COME BY EVEN IF LIGHT RAIN DEVELOPS SO PLAN TO CONTINUE CARRYING
SLIGHT CHC/LOW CHC ALONG THE COAST WITH POP AROUND 10 INLAND.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN AND A LITTLE LESS MARINE
INFLUENCE. LOW TEMPERATURES WILL END UP A LITTLE ABOVE CLIMO DUE TO
CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...HIGH PRESSURE WEDGE IN PLACE AT THE START OF
THE PERIOD WILL HOLD ON INTO AT LEAST THE SECOND HALF OF THE
WEEKEND...KEEPING TEMPERATURES IN MOST AREAS A LITTLE BELOW CLIMO.
GUIDANCE IS SHOWING HINTS THE WEDGE COULD HOLD ON INTO MON GIVEN THE
LACK OF SURFACE AND MID LEVEL FEATURES. THIS WOULD MAINTAIN LOW
CLOUDS AND LIGHT PRECIP...MAINLY ALONG THE COAST...INTO NEXT WEEK.
FARTHER INLAND THERE IS LIKELY TO BE A NARROW GRADIENT BETWEEN
MOSTLY CLOUDY AND MOSTLY SUNNY. THIS IS COMPLICATED SOMEWHAT BY
POTENTIAL WEAK LOW PRESSURE DEVELOPING ALONG THE FRONT STALLED
OFFSHORE. THIS FEATURE COULD ENHANCE THE WEDGE AS IT MOVES UP THE
COAST BEFORE HELPING TO BREAK THE WEDGE AS IT EXITS NORTHEAST.
HOWEVER ITS INFLUENCE ON THE AREA REMAINS IN QUESTION WITH MANY OF
THE MEDIUM RANGE SOLUTIONS KEEPING THIS FEATURE ON THE WEAK SIDE AND
FARTHER OFF THE COAST.
COLD FRONT APPROACHES FROM THE NORTHWEST MON...DRIVEN SOUTH BY
STRONG MID LEVEL TROUGH DIVING SOUTH ACROSS THE GREAT LAKES AND
CANADIAN HIGH PRESSURE. FROPA DURING THE DAY MON WILL HAVE SOME
DIURNAL INSTABILITY TO WORK WITH...BUT HOW MUCH REMAINS A QUESTION.
EXPECT CONVECTION AHEAD OF THE FRONT BUT STRENGTH AND COVERAGE WILL
PARTLY DEPEND ON TIMING. FRONT STALLS OFFSHORE MON NIGHT INTO
TUE...SIMILAR TO THIS WEEKS COLD FRONT AS SURFACE HIGH BUILDS IN
FROM THE GREAT LAKES.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE HRRR SUGGESTS SLOW-MOVING SHOWER/TSTM ACTIVITY
ALONG THE COLD FRONT MAY STILL PLAGUE OUR INLAND TAF SITES AT THE
START OF THE PERIOD. THEREFORE WILL INCLUDE VCSH FOR KFLO/KLBT
FROM 06-08Z. INCREASING DEBRIS CLOUDS FROM FRONTAL CONVECTION WILL
LIKELY LIMIT FOG POTENTIAL OVERNIGHT. HAVE JUST INCLUDED TEMPO
MVFR VSBYS... MAINLY EARLY IN THE PERIOD AS THE NORTHEASTERLY
SURGE AFTER 09Z OR SO SHOULD MIX OUT ANY LINGERING BR. COULD ALSO
SEE SOME MVFR CIGS DEVELOP BEHIND THE FRONT THIS MORNING...BUT IFR
POTENTIAL APPEARS LOW EVEN FOR THE INLAND TERMS. MVFR CIGS COULD
LINGER THROUGH THE LATE MORNING HOURS BEFORE IMPROVING TO VFR BY
MIDDAY. EXPECT NE WINDS AOB 10 KT BEHIND THE FRONT TO PERSIST
THROUGH THE PERIOD.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...A LIGHT EAST TO NORTHEASTERLY FLOW OF
AROUND 10 KTS WILL DEVELOP OVER THE WATERS TODAY AND TONIGHT AS A
COLD FRONT DROPS SOUTH OF THE AREA. WIND WAVES WILL BE IN THE
MODEST 1 TO 2 FT RANGE...BUT WILL BE SUPPLEMENTED BY SWELL FROM
DISTANT HURRICANE EDOUARD...BRINGING A COMBINED SEA HEIGHT RANGING
FROM 2 TO 4 FT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY....LIGHT NORTHEAST FLOW ON THU WILL INCREASE
SIGNIFICANTLY FRI AS HIGH PRESSURE BUILDS DOWN THE COAST AND
GRADIENT BECOMES PINCHED. THU NORTHEAST FLOW WILL BE IN THE REALM OF
10 KT BUT BY MIDDAY FRI SOLID 20 KT WITH HIGHER GUSTS IS EXPECTED.
SEAS 2 TO 4 FT THU FLIRTS WITH HEADLINE CRITERIA FRI...ESPECIALLY
NORTH OF CAPE FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT
ACROSS PARTS OF NC WATERS.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY....ELEVATED NORTHEAST FLOW CONTINUES SAT AS
HIGH PRESSURE RIDGES DOWN THE COAST. GRADIENT WILL MAINTAIN 15 TO 20
KT WINDS SAT BUT WEAKENING GRADIENT SUN WILL ALLOW FOR A REDUCTION
IN SPEEDS. WEAK LOW PRESSURE PASSES EAST OF THE WATERS SUN. IN THE
WAKE OF THIS LOW SUN NIGHT LIGHT SOUTHWEST FLOW WILL DEVELOP. SEAS 3
TO 5 FT WITH OCCASIONAL 6 FT POSSIBLE SAT DECREASE TO 2 TO 4 FT SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
119 AM EDT WED SEP 17 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE LATE TONIGHT. HIGH PRESSURE WILL
EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:30 AM WEDNESDAY...LINE OF CONVECTION DROPPING FROM THE
NORTH BREAKING UP TO SOME EXTENT AND IS NOT AS STRONG/SOLID AS
BEFORE. THIS TREND WILL CONTINUE UNTIL ACTIVITY MOVES OFFSHORE IN
THE EARLY MORNING HOURS. PREVIOUS DISCUSSION FOLLOWS:
QUITE A LINE OF CONVECTION HAS DEVELOPED OVER THE PAST FEW HOURS
EXTENDING FROM THE SOUTH SIDE OF CHARLOTTE EASTWARD ACROSS
ROCKINGHAM...FAYETTEVILLE...AND APPROACHING CLINTON. SPC
MESOANALYSIS INDICATES SURFACE-BASED PARCELS ARE CAPPED...WHICH
MAKES SENSE GIVEN SURFACE TEMPERATURES IN THE LOWER 70S. ELEVATED
CAPE OF 750-1000 J/KG WITH MINIMAL CAPPING IS AVAILABLE WHEN
PARCELS AROUND 950-925 MB ARE CONSIDERED. MID-LEVEL LAPSE RATES
ARE RATHER STEEP AT 6 DEG C/KM. ALTHOUGH CONVECTION HAS MERGED
INTO A LINE EARLIER THERE WERE HINTS OF SUPER CELLULAR
CHARACTERISTICS AS A BELT OF STRONGER MID-LEVEL FLOW ACROSS NORTH-
CENTRAL NORTH CAROLINA IS PRODUCING 0-6 KM BULK SHEAR VALUES NEAR
30 KNOTS.
THE SURFACE COLD FRONT IS LOCATED 50-100 MILES BEHIND THE
CONVECTION...CURRENTLY EXTENDING ACROSS THE NORTHERNMOST ROW OF
COUNTIES IN NORTH CAROLINA. ALTHOUGH PRESSURES ARE CURRENTLY STEADY
ACROSS THE AREA WE ANTICIPATE FALLING PRESSURES TO DEVELOP ALONG THE
COAST AND OFFSHORE SHORTLY AS LOW PRESSURE DEVELOPS. THIS LOW WILL
PULL THE FRONT DOWN LATE TONIGHT AND OFFSHORE BY DAYBREAK.
SINCE THE CONVECTION IS ELEVATED AND BASED WITHIN A UNIFORM 950-900
MB LAYER IT SHOULD RESPOND MORE TO OVERALL SYNOPTIC FORCING THAN TO
ANYTHING GOING ON HERE AT THE SURFACE. THE UPPER DISTURBANCE IS
LOCATED NEAR I-77 NORTH OF CHARLOTTE AND SHOULD MOVE
EAST-NORTHEASTWARD THROUGH THE NIGHT. AS THE STORMS DRIFT SOUTH THEY
WILL MOVE OUT OF THE INFLUENCE OF THE UPPER TROUGH AND SHOULD
WEAKEN. THIS IS SHOWN BY THE 23Z RUN OF THE HRRR...WHICH ALSO
INDICATES THE CONVECTION MAY JUMP WILMINGTON AND
SOUTHPORT...REDEVELOPING OFFSHORE AFTER 2-3 A.M. WITHIN A REGION OF
SURFACE-BASED INSTABILITY OVER THE WARM OCEAN WATER.
NO CHANGES HAVE BEEN MADE TO FORECAST LOWS...STILL ANTICIPATED TO
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEAK LOW PRESSURE ALONG LINGERING FRONT
WILL GET PUSHED FARTHER OFF SHORE AS HIGH PRESSURE BUILDS DOWN
FROM THE NORTHWEST THROUGH MID WEEK. THE EASTERLY FLOW AROUND THE
TOP OF THE LOW WILL COME UP AGAINST W-NW FLOW AS HIGH PRESSURE
BUILDS IN. THIS WILL PRODUCE SOME LOW LEVEL CONVERGENCE THROUGH WED
AND THE LAST BIT OF ENERGY IN THE MID LEVELS WILL ROUND THE BASE
OF THE TROUGH BEFORE IT LIFTS OFF TO THE NORTHEAST. THEREFORE WILL
KEEP SOME CLOUDS AND POPS IN FORECAST ON WED. THE MID TO UPPER
TROUGH RUNNING DOWN THE EAST COAST WILL SHIFT SLOWLY EAST AND WILL
LIFT FARTHER OFF TO THE NORTHEAST WED INTO THURS. AS TROUGH AXIS
CROSSES THE COAST EARLY THURS...A DEEPER N-NW FLOW WILL ESTABLISH
ITSELF OVER THE CAROLINAS WITH CONSIDERABLE DRYING AND SUBSIDENCE
THROUGH THE MID LEVELS. HIGH PRESSURE WILL BUILD IN WITH LIGHT
NORTHERLY WINDS VEERING AROUND TO THE NE THROUGH LATE THURS. PCP
WATER VALUES DROP FROM AROUND 1.5 INCHES WED AFTN DOWN CLOSER TO
AN INCH BY THURS EVE. DEWPOINT TEMPS IN THE MID TO UPPER 60S WED
AFTN WILL DROP INTO THE LOWER 60S THROUGH THURS. OVERALL EXPECT
CONDITIONS TO IMPROVE WITH INCREASING SUNSHINE AND MORE FALL LIKE
WEATHER.
AS AIR MASS TRANSITIONS TO A DRIER MORE SEASONABLE AIR MASS...SO
WILL THE TEMPS. TEMPS OVERNIGHT WED WILL BE WARMER THAN THURS
NIGHT BY A COUPLE OF DEGREES...MID 60S BOTH NIGHTS. TEMPS WILL
REACH INTO THE 80S ON WED BUT ON THURS TEMPS WILL RUN A FEW
DEGREES COOLER EVEN WITH A GREATER AMOUNT OF SUNSHINE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...ON FRIDAY A LARGE AREA OF COOL HIGH PRESSURE
WILL BE SLIDING EAST ACROSS NEW ENGLAND. THIS ANTICYCLONE WILL HAVE
A RIDGE AXIS EXTENDING ALL THE WAY DOWN INTO THE CAROLINAS. FLOW
ALOFT WILL BE VERY WEAK BUT STILL HAVE SOME SENSE OF TROUGHINESS.
MODELS HAVING A HARD TIME TELLING HOW MUCH THIS TROUGHINESS ERODES
THE EASTERN PERIPHERY OF THE SURFACE RIDGE. THE MORE AGGRESSIVE GFS
MANAGES TO FLING MOISTURE ASHORE AND HAS THE SUPPORT OF THE CMC. THE
(00Z) ECMWF DOES THE SAME BUT WITH A MUCH SLOWER SENSE OF TIMING
KEEPING MOST PLACES DRY TIL SUNDAY. WILL SHOW JUST SLIGHT CHANCE
POPS ALONG THE COAST THROUGH THESE DAYS. THE WEDGE APPEARS TO WASH
OUT BY MONDAY AT WHICH TIME RAIN CHANCES SHIFT TO BEING TIED TO A
DEVELOPING PIEDMONT TROUGH AND TEMPS REBOUND TO NORMAL OR HIGHER. A
COLD FRONT APPEARS SLATED FOR A MONDAY NIGHT ARRIVAL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE HRRR SUGGESTS SLOW-MOVING SHOWER/TSTM ACTIVITY
ALONG THE COLD FRONT MAY STILL PLAGUE OUR INLAND TAF SITES AT THE
START OF THE PERIOD. THEREFORE WILL INCLUDE VCSH FOR KFLO/KLBT
FROM 06-08Z. INCREASING DEBRIS CLOUDS FROM FRONTAL CONVECTION WILL
LIKELY LIMIT FOG POTENTIAL OVERNIGHT. HAVE JUST INCLUDED TEMPO
MVFR VSBYS... MAINLY EARLY IN THE PERIOD AS THE NORTHEASTERLY
SURGE AFTER 09Z OR SO SHOULD MIX OUT ANY LINGERING BR. COULD ALSO
SEE SOME MVFR CIGS DEVELOP BEHIND THE FRONT THIS MORNING...BUT IFR
POTENTIAL APPEARS LOW EVEN FOR THE INLAND TERMS. MVFR CIGS COULD
LINGER THROUGH THE LATE MORNING HOURS BEFORE IMPROVING TO VFR BY
MIDDAY. EXPECT NE WINDS AOB 10 KT BEHIND THE FRONT TO PERSIST
THROUGH THE PERIOD.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
WINDS ACROSS THE NC WATERS ARE GENERALLY FROM THE SOUTH OR
SOUTHEAST WITH A MORE VARIABLE PATTERN NOTED ACROSS THE SOUTH
CAROLINA WATERS. PRESSURES SHOULD BEGIN TO FALL SHORTLY ALONG THE
COAST AS LOW PRESSURE DEVELOPS OFFSHORE. THIS LOW WILL PULL THE
COLD FRONT...CURRENTLY ACROSS NORTHERN NORTH CAROLINA...SOUTHWARD
AND OFF THE COAST BY DAYBREAK WITH NORTHERLY WINDS EXPECTED TO
DEVELOP. A LINE OF THUNDERSTORMS ACROSS THE INTERIOR COASTAL PLAIN
WILL PROBABLY WEAKEN BEFORE MAKING IT TO THE BEACHES...HOWEVER
CONDITIONS FAVOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS OUT
AHEAD OF THIS LINE AFTER MIDNIGHT...MOST LIKELY IN THE 2-4 AM TIME
FRAME. SEAS CURRENTLY 1-2 FT MAY BEGIN TO BUILD TOWARD 3 FEET
ACROSS THE OUTERMOST PORTION OF THE COASTAL WATERS LATE TONIGHT AS
SWELL FROM DISTANT HURRICANE EDOUARD FINALLY MAKES IT TO THE
COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WILL MAINTAIN E-NE WINDS THROUGH MID WEEK
AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH. INITIALLY WINDS WILL
BE LIGHTER AND MORE EASTERLY. THE ON SHORE FLOW UP TO 10 KTS ON
WED WILL COMBINE WITH THE SEA BREEZE AND A LONG PERIOD UP TO 16
SEC EASTERLY SWELL TO PUSH SEAS UP TO 2 TO 4 FT WITH SOME 5 FTERS
IN OUTER WATERS WED AFTN. THE LONGER PERIOD EASTERLY SWELLS FROM
EDOUARD WELL OUT IN THE ATLANTIC WATERS WILL PEAK AROUND 16
SECONDS VERY EARLY WED AND WILL DIMINISH SLOWLY THROUGH THURS.
SEAS WILL ACTUALLY DROP SLIGHTLY THROUGH EARLY THURS BUT A SLIGHT
INCREASE IN NE WINDS UP TO 10-15 KNOTS THROUGH THUR NIGHT SHOULD
PRODUCE ANOTHER SPIKE IN SEAS BY FRI MORNING.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A WEDGE OF HIGH PRESSURE MORE REMINISCENT OF
THE COOL SEASON WILL DEVELOP ON FRIDAY. THE PINCHED NORTHEASTERLY
GRADIENT COULD YIELD A FEW ADVISORY-WORTHY 6 FT SEAS INTO NRN
ZONES...BUT WNA GUIDANCE HAS COME DOWN FROM PREVIOUS RUNS AND IT
MAY BE QUITE MARGINAL. CURRENT FCST STILL SHOWING A RAMP UP TO 4
TO 6 THOUGH. WAVE SHADOWING WILL PRECLUDE ADVISORY OVER SOUTHERN
WATERS. A MODERATE NORTHEASTERLY FLOW WILL REMAIN IN PLACE FOR THE
REST OF THE PERIOD WITH A GRADUAL DECREASE IN STRENGTH. BORDERLINE
SCEC/ADVISORY MAY CONTINUE OVER NRN ZONES INTO SATURDAY. FURTHER
WEAKENING OF THE HIGH PRESSURE WILL BRING QUIETER CONDITIONS COME
SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...REK/RJD/TRA
SHORT TERM...RGZ
LONG TERM...MBB
AVIATION...BJR
MARINE...REK/RJD/TRA/MBB/RGZ
AREA FORECAST DISCUSSION
NWS TULSA OK
333 AM CDT WED SEP 17 2014
.DISCUSSION...
THUNDERSTORMS HAVE BLOSSOMED OVER EASTERN KANSAS WITHIN THE PAST
HOUR OR TWO IN RESPONSE TO A DISTURBANCE IN THE CENTRAL PLAINS AND
THE APPROACH OF A STRONG UPPER JET. MOVEMENT OF THE CURRENT
ACTIVITY CONFIRMS THE LOCAL WRF AND HRRR SOLUTIONS THAT KEEP THE
BULK OF THIS NORTH OF THE OKLAHOMA AND ARKANSAS BORDERS UNTIL THIS
AFTERNOON. WILL CONTINUE WITH SMALL POPS IN FAR NORTHEAST OKLAHOMA
AND FAR NORTHWEST ARKANSAS THROUGH THE MORNING HOURS...WITH HIGHER
CHANCES THIS AFTERNOON AND INTO TONIGHT. ONGOING PATCHY BUT
OCCASIONALLY DENSE FOG IN NORTHWEST ARKANSAS SHOULD BE GONE
SHORTLY AFTER SUNRISE. PER SURFACE OBS...VISIBILITIES HAVE VARIED
WILDLY THIS MORNING AT ANY ONE LOCATION WHICH COULD MAKE FOR A
DIFFICULT COMMUTE ESPECIALLY IN THE BENTON AND WASHINGTON
COUNTIES. AFTERNOON TEMPERATURES TODAY LOOK TO BE ABOVE NORMAL IN
MOST AREAS...WITH SOME SPOTS ALONG AND WEST OF HIGHWAY 75 LIKELY
TO TOUCH 90 DEGREES.
ANOTHER ROUND OF THUNDERSTORMS SHOULD DEVELOP AND AFFECT A BIGGER
SECTION OF EASTERN OKLAHOMA AND WESTERN ARKANSAS LATE TONIGHT AND
PERHAPS INTO TOMORROW AS ANOTHER SEGMENT OF THE UPPER JET
STRENGTHENS TO OUR EAST AND A DISTURBANCE MOVES THROUGH MISSOURI
AND ARKANSAS. A BRIEF DRYING TREND STILL APPEARS TO BE IN THE
OFFING FOR FRIDAY AND INTO FRIDAY NIGHT...AS UPPER RIDGING QUICKLY
BUILDS INTO THE PLAINS.
THE PATTERN WILL REMAIN FAIRLY PROGRESSIVE...HOWEVER...AS A STRONG
COLD FRONT IS STILL ON TRACK FOR THE WEEKEND. WITH THE REMNANTS OF
ODILE MOVING INTO THE REGION...A HEAVY RAIN EVENT CONTINUES TO
LOOK LIKELY SOMEWHERE IN THE SOUTHERN OR CENTRAL PLAINS. WITH THE
EXCEPTION OF YESTERDAYS 12Z RUN OF THE ECMWF...MOST MEDIUM RANGE
MODEL SOLUTIONS STILL PLACE THE HEAVY RAIN AXIS TO OUR
NORTH...WHILE STILL ALLOWING FOR SOME BENEFICIAL RAIN AMOUNTS
ACROSS PARTS OF NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS.
TIMING OF THE HEAVIEST RAIN CURRENTLY LOOKS TO BE BETWEEN 18Z
SATURDAY AND 06Z SUNDAY. THE RAIN SHOULD CLEAR QUICKLY ENOUGH TO
ALLOW FOR A DRY BUT COOL BEGINNING TO NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 89 69 88 69 / 10 30 30 10
FSM 86 68 85 67 / 20 40 40 10
MLC 88 71 87 68 / 10 20 30 10
BVO 90 67 87 67 / 10 40 30 10
FYV 83 65 83 64 / 30 60 40 10
BYV 82 64 80 64 / 50 60 40 10
MKO 87 68 86 67 / 10 20 40 10
MIO 85 67 84 66 / 50 60 40 10
F10 87 69 87 68 / 10 20 30 10
HHW 88 70 88 68 / 10 20 40 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...05
LONG TERM....22
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 AM CDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT WED SEP 17 2014
LATEST INFARED SATELLITE IMAGERY INDICATE STRATOCUMULUS DECK ACROSS
SOUTHERN MINNESOTA INTO IOWA. THIS IS IN ASSOCIATION WITH A WEAK
IMPULSE OVER SOUTHWEST MINNESOTA AND NORTHWEST IOWA EVIDENT ON
LATEST WATER VAPOR SATELLITE IMAGERY. LATEST 07Z SURFACE ANALYSIS
SHOWS RIDGE OF HIGH PRESSURE EXTENDING FROM NORTHERN ILLINOIS
INTO NORTHERN WISCONSIN. WITH CLEAR SKIES AND LIGHT WINDS EAST OF
THE MISSISSIPPI RIVER...TEMPERATURES HAVE FALLEN INTO THE MIDDLE
TO UPPER 30S ACROSS CENTRAL WISCONSIN PER LATEST 07Z METARS.
MAIN FORECAST CONCERN TONIGHT IS FOG POTENTIAL IN RIVER VALLEYS
AND CLOUD FORMATION OVER NORTHERN WISCONSIN.
THE LATEST 17.00Z GFS/NAM PUSH WEAK IMPULSE SOUTH OF THE FORECAST
AREA THIS MORNING AND THIS WILL CONTINUE TO ADVECT THE STRATOCUMULUS
DECK OVER THE FORECAST AREA THROUGH 18Z. ANY RESIDUAL MOISTURE
LEFT WITH DEPARTING IMPULSE WILL EVAPORATE DUE DAYTIME HEATING AND
ALLOW SKIES TO BECOME MOSTLY SUNNY AFTER 18Z.
FOCUS TURNS TO FOG POTENTIAL TONIGHT. THE LATEST 17.00Z
GFS/NAM/ECMWF CONTINUE TO PUSH WEAK SURFACE FRONT NORTH TO SOUTH
ACROSS THE FORECAST AREA THIS EVENING. ALL MODELS INDICATE 850MB
MOISTURE ALONG WEAK SURFACE FRONT AND PRODUCE CLOUDS EAST OF THE
MISSISSIPPI RIVER...MAINLY OVER CENTRAL WISCONSIN. THE QUESTION WILL
BE HOW FAR SOUTH AND WEST THE DECK OF CLOUDS WILL BE TO INHIBIT ANY
RIVER VALLEY FOG FORMATION AFTER 06Z THURSDAY. THE 17.00Z GFS/NAM
BUFKIT SOUNDINGS SHOW WINDS LIGHT ENOUGH UNDER INVERSION AFTER 06Z
THURSDAY AND NEAR SURFACE BOUNDARY LAYER MOISTENING. THIS WOULD
SUGGEST FOG IS POSSIBLE IN RIVER VALLEYS AND WILL DEPEND ON IF ANY
CLOUDS MOVE OVER SOUTHWEST AND WESTERN WISCONSIN TO INHIBIT
FORMATION OF FOG. FOR NOW...HAVE LEFT MENTION OF FOG IN RIVER
VALLEYS IN FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 318 AM CDT WED SEP 17 2014
THE 17.00Z GFS/NAM/ECMWF LINGER THE 900-850MB MOISTURE OVER
CENTRAL WISCONSIN INTO THURSDAY PER BUFKIT SOUNDINGS. IF CLOUDS
FORM AND LINGER OVER THIS AREA. TEMPERATURES MAY NOT REACH THE
CURRENT FORECAST HIGHS OVER CENTRAL WISCONSIN.
MAIN FORECAST CONCERNS THURSDAY NIGHT THROUGH SATURDAY ARE
PRECIPITATION CHANCES. THE 17.00Z GFS/NAM/ECMWF/GEM CONTINUE TO
INDICATE TIMING DIFFERENCES WITH SHORTWAVE TROUGH AND ASSOCIATED
SURFACE FRONT MOVING INTO THE GREAT LAKES REGION. THE 17.00Z ECMWF
IS TRENDING TOWARDS A BROADER AND MORE PROGRESSIVE SOLUTION THAN THE
GFS/GEM. THE 17.00Z GFS/GEM/ECMWF/NAM FOCUS LIFT/MOISTURE
TRANSPORT AND CONVERGENCE OVER THE NORTHERN SECTIONS OF THE
FORECAST AREA MAINLY AFTER 18Z FRIDAY IN ASSOCIATION WITH THE FIRST
IMPULSE. HENCE...HIGHER PRECIPITATION CHANCES OVER THIS AREA.
SHORTWAVE RIDGE REMAINS ENTRENCHED OVER THE SOUTHERN FORECAST AREA
AND ALLOW FOR LESSER TO NO PRECIPITATION CHANCES OVER THE SOUTHERN
FORECAST AREA FRIDAY.
MAIN SHORTWAVE TROUGH DIGS INTO THE GREAT LAKES REGION AND SURFACE
FRONT MOVES ACROSS THE FORECAST AREA FRIDAY NIGHT INTO SATURDAY
MORNING. WITH THE TIMING DIFFERENCES BETWEEN THE 17.00Z
GFS/NAM/ECMWF/GEM...CONFIDENCE IN EXACT TIMING OF THUNDERSTORMS
CONTINUES TO BE LOW. THE 17.00Z GFS/GEM/ECMWF/NAM INDICATE DECENT QG
FORCING/LIFT/MOISTURE TRANSPORT AND CONVERGENCE ASSOCIATED WITH
TROUGH/SURFACE FRONT FRIDAY NIGHT INTO SATURDAY MORNING. MUCH OF
THE AREA SHOULD SEE SHOWERS AND THUNDERSTORMS. MODELS CONTINUE TO
PROG HIGH PRECIPITABLE WATER VALUES...INSTABILITY AND SHEAR WITH
THE SURFACE FRONT/SHORTWAVE TROUGH. A FEW OF THE THUNDERSTORMS
COULD POTENTIALLY BECOME SEVERE.
SURFACE RIDGE BUILDS INTO THE GREAT LAKES REGION SUNDAY NIGHT INTO
TUESDAY AND PROVIDE DRIER WEATHER CONDITIONS ACROSS THE FORECAST
AREA. COOLER AIR WILL FILTER IN BEHIND THE SURFACE FRONT/SHORTWAVE
TROUGH AND TEMPERATURES SHOULD BE NEAR NORMAL EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CDT TUE SEP 16 2014
STILL SOME UNCERTAINTIES AS TO WHETHER FOG WILL FORM IN THE
MISSISSIPPI RIVER VALLEY TONIGHT. THE 17.02Z RAP AND 17.00Z NAM
BOTH CONTINUE TO SHOW THE WINDS JUST ABOVE THE SURFACE INCREASING
OVERNIGHT AS THE SURFACE HIGH OVER ILLINOIS MOVES OFF INTO THE
OHIO RIVER VALLEY. HAVE NOTICED THROUGH THE EVENING THAT THE FLAG
HERE AT THE OFFICE HAS BEEN MOVING AROUND AT TIMES AND THE VWP
WINDS FOR THE KARX RADAR HAVE BEEN SHOWING 10 KNOTS AT 1000 FEET
ALL EVENING WITH INCREASING WINDS ABOVE THAT. BOTH MODELS ALSO
CONTINUE TO SHOW SATURATION OCCURRING RIGHT AT THE SURFACE AND
WITH A 4 DEGREE TEMP/DEW POINT SPREAD AT 17.04Z THIS COULD ALLOW
SOME FOG TO FORM NEAR THE AIRPORT AND WILL CONTINUE WITH BCFG BUT
NOT SHOW ANYTHING MORE THAN THAT GIVEN THE WINDS ALOFT.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS A WEAK
COLD FRONT SLIDES THROUGH WEDNESDAY AFTERNOON FOLLOWED BY ANOTHER
AREA OF HIGH PRESSURE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1144 PM CDT TUE SEP 16 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 228 PM CDT TUE SEP 16 2014
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING AGAIN OVER WESTERN NORTH AMERICA WHILE TROUGHING
DOMINATES EASTERN CANADA INTO THE GREAT LAKES AND OHIO VALLEY. THIS
PLACES THE FORECAST AREA IN A SUBSIDENT NORTHWEST FLOW REGIME...
FAVORING DRY CONDITIONS AND HIGH PRESSURE AT THE SURFACE. LATEST
SURFACE ANALYSIS SHOWED THE HIGH CENTERED OVER ILLINOIS WITH A RIDGE
AXIS EXTENDING INTO WESTERN WI. AIRMASS OVER THE AREA HAS WARMED
SLIGHTLY FROM YESTERDAY WITH 925MB TEMPS UP TO 10C. HOWEVER...MORE
SUNSHINE AND A DRIER AIRMASS REFLECTED BY PRECIPITABLE WATER VALUES
OF 0.3-0.5 INCHES PER PRECIPITABLE WATER IMAGERY HAS ALLOWED
TEMPERATURES TO CLIMB INTO THE 60S.
THE SHORT TERM PERIOD AGAIN LOOKS QUIET...RESULTING FROM PLENTIFUL
DRY AIR IN PLACE OVER THE NEXT 24 HOURS TO PREVENT PRECIPITATION.
HOWEVER...THERE ARE A FEW ISSUES TO CONTEND WITH...
1. POTENTIAL FOR VALLEY FOG TONIGHT. THE RIDGE AXIS EXTENDING FROM
THE SURFACE HIGH IN ILLINOIS INTO WESTERN WI IS PROGGED TO STAY IN
PLACE THROUGH WEDNESDAY MORNING. WITH DRY AIR IN PLACE...LIGHT WINDS
AND CURRENTLY CLEAR SKIES...TEMPERATURES SHOULD DROP QUICKLY.
HOWEVER...THERE ARE 3 PROBLEMS FOR VALLEY FOG. THE FIRST IS THAT THE
AIR IS MUCH DRIER TODAY COMPARED TO YESTERDAY AT THIS TIME...AND ALL
RAIN FROM YESTERDAY HAS BEEN ABSORBED. SECOND...THE GFS...NAM AND
RAP HAVE ALL TRENDED STRONGER WITH THE WIND FIELD AFTER MIDNIGHT...
WITH POTENTIAL OF UP TO 20 KT SUGGESTED RIGHT ABOVE THE SURFACE.
THESE WINDS COULD REALLY HAMPER FOG AND EVEN STRATUS TRYING TO STICK
AROUND IN THE MISSISSIPPI VALLEY. THIRD...A NEW DISCOVERY TODAY IS
THAT BOTH THE GFS AND NAM SHOW A BAND OF MID CLOUDS MOVING INTO THE
WESTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. THESE CLOUDS MATCH
UP VERY WELL WITH ISENTROPIC LIFT SEEN ON THE 300K SURFACE...WHICH
COULD ALSO HAMPER FOG AND STRATUS FROM STICKING AROUND...EVEN IN THE
TRIBS. THUS...HAVE BACKED DOWN THE COVERAGE OF VALLEY FOG AND
STRATUS OVERNIGHT INTO WEDNESDAY MORNING.
2. TEMPS AND FROST POTENTIAL TONIGHT. RELATED TO THE VALLEY FOG
DISCUSSION ABOVE... READINGS IN CENTRAL WISCONSIN LOOK TO PLUMMET
AGAIN. FOLLOWED PREVIOUS FORECAST IN DROPPING TEMPERATURES TOWARDS
THE MID 30S. THEY SHOULD STAY HIGH ENOUGH TO PRECLUDE FROST
FORMATION...THOUGH. ALONG/WEST OF THE RIVER...INCREASING WIND AND
INCOMING CLOUDS RESULT IN WARMER READINGS.
3. BACKDOOR COLD FRONT WEDNESDAY AFTERNOON. THIS FRONT HAS BEEN
SHOWN FOR MANY DAYS TO COME INTO THE REGION FROM THE NORTH. DRY AIR
WILL PREVENT PRECIPITATION...HOWEVER...THE FRONT SHOULD PULL SOME
WARMER AIR IN AHEAD OF IT TO ALLOW FOR HIGHS TO BE ABOUT 5 DEGREES
WARM THAN TODAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 228 PM CDT TUE SEP 16 2014
QUIET WEATHER CONTINUES FOR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
AS A CANADIAN HIGH DROPS DOWN INTO THE GREAT LAKES REGION BEHIND THE
BACKDOOR COLD FRONT. MAY HAVE TO CONTEND WITH SOME STRATUS IN THE
WAKE OF THE FRONT...AS WELL AS AN INCREASING EAST-SOUTHEAST
WIND...BOTH OF WHICH COULD IMPACT VALLEY FOG FORMATION/PERSISTENCE.
MUCH OF THE COOLING BEHIND THE FRONT STILL APPEARS TO GET DEFLECTED
TO THE EAST...THUS HIGHS ON THURSDAY ARE ONLY ANTICIPATED TO BE
SLIGHTLY COOLER THAN WEDNESDAY.
MUCH OF THE LONG TERM FOCUS IS AFTER MIDNIGHT THURSDAY NIGHT THROUGH
SATURDAY. MODELS REMAIN IN GOOD AGREEMENT ON BUILDING UPPER RIDGING
INTO THE REGION ON FRIDAY...AHEAD OF A SHORTWAVE TROUGH CROSSING THE
NORTHERN ROCKIES. THIS SETS UP A FAIRLY SIGNIFICANT WARM ADVECTION
REGIME OVER THE FORECAST AREA...WITH 850MB TEMPS CLIMBING 8-10C
BETWEEN 00Z FRI AND 00Z SAT. THIS REGIME ALSO COMES WITH MORE
MOISTURE...AS PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.7 INCHES
AT 00Z FRI TO AROUND 1.5 INCHES BY 18Z FRI. THESE TWO PARAMETERS
INCREASING SIGNIFICANTLY BRINGS UP A CONCERN FOR ELEVATED
CONVECTION. 850MB MOISTURE TRANSPORT PROGS FROM THE 16.12Z
NAM/GFS/ECMWF WOULD SUGGEST POSSIBLE CONVECTION FIRING WEST OF I-35
IN MN AND IA BETWEEN 06-12Z FRI...THEN LIFTING NORTHEAST INTO
NORTHERN WI BY 00Z SAT AS CAPPING BUILDS IN. THUS...SOME SHOWER AND
THUNDERSTORM CHANCES PERSIST FOR FRI...ESPECIALLY NORTH OF I-90.
CAPE AND SHEAR PROFILES WOULD SUGGEST NO SEVERE WEATHER WITH THIS
ACTIVITY. GREATER CHANCES FOR WIDESPREAD RAIN LOOK TO COME AFTER
MIDNIGHT FRIDAY NIGHT INTO SATURDAY. THIS IS WHEN THE TROUGH MAKES
ITS WAY EAST AND THROUGH THE REGION...FOLLOWED WITH AN ASSOCIATED
SURFACE COLD FRONT FOR CONVERGENCE. PLENTIFUL MOISTURE CHARACTERIZED
BY THE AFOREMENTIONED 1.5 INCH PRECIPITABLE WATER WILL ALSO HELP.
HARD TO SAY AT THIS TIME IF THE MID LEVEL CIRCULATION OF TROPICAL
STORM ODILE OVER BAJA CALIFORNIA WILL GET PULLED UP INTO THE REGION
OR NOT. IF IT DOES...THE CHANCES FOR PRECIPITATION...AND HEAVY
PRECIPITATION AT THAT WOULD INCREASE. TIMING OF THE FRONT WILL BE
CRITICAL TO WHEN AND WHERE POTENTIAL EXISTS FOR SEVERE WEATHER.
16.12Z ECMWF POINTS TO FRIDAY EVENING ACROSS THE NORTHWEST HALF OF
THE FORECAST AREA...WHILE THE 16.12Z GFS WOULD BE SATURDAY AFTERNOON
OVER THE SOUTHEAST HALF.
SOMETHING ALSO TO KEEP A CLOSE EYE ON IS WINDS ON FRIDAY ACROSS
SOUTHEAST MN. WITH 40 TO PERHAPS AS HIGH AS 60KT SOUTHWEST
WINDS...STRONGEST IF YOU BELIEVE THE NAM...PROGGED BETWEEN 3000-5000
FT ABOVE THE GROUND...MIXING SHOULD EASILY CREATE GUSTS NEAR 30 KT.
THESE IN LATER FORECASTS COULD GET CLOSE TO WIND ADVISORY CRITERIA
IF MORE SUN OCCURS.
FOR SUNDAY INTO TUESDAY...MODELS REAMPLIFY TROUGHING OVER EASTERN
CANADA INTO THE GREAT LAKES REGION...SIMILAR TO WHAT IS GOING ON
TODAY. THERE REMAINS UNCERTAINTY IF A MORE POTENT SHORTWAVE WILL
DIVE THROUGH THE TROUGH AND THROUGH THE FORECAST AREA...BUT TRENDS
SEEM TO SUGGEST THAT THE TRACK OF SUCH WAVE WILL END UP NORTHEAST OF
THE AREA. THEREFORE...THE FORECAST STAYS DRY WITH THE COOLER AIR
STAYING TO THE NORTH AND EAST. STILL...WE SHOULD SEE TEMPERATURES
FALL BACK TO JUST BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CDT TUE SEP 16 2014
STILL SOME UNCERTAINTIES AS TO WHETHER FOG WILL FORM IN THE
MISSISSIPPI RIVER VALLEY TONIGHT. THE 17.02Z RAP AND 17.00Z NAM
BOTH CONTINUE TO SHOW THE WINDS JUST ABOVE THE SURFACE INCREASING
OVERNIGHT AS THE SURFACE HIGH OVER ILLINOIS MOVES OFF INTO THE
OHIO RIVER VALLEY. HAVE NOTICED THROUGH THE EVENING THAT THE FLAG
HERE AT THE OFFICE HAS BEEN MOVING AROUND AT TIMES AND THE VWP
WINDS FOR THE KARX RADAR HAVE BEEN SHOWING 10 KNOTS AT 1000 FEET
ALL EVENING WITH INCREASING WINDS ABOVE THAT. BOTH MODELS ALSO
CONTINUE TO SHOW SATURATION OCCURRING RIGHT AT THE SURFACE AND
WITH A 4 DEGREE TEMP/DEW POINT SPREAD AT 17.04Z THIS COULD ALLOW
SOME FOG TO FORM NEAR THE AIRPORT AND WILL CONTINUE WITH BCFG BUT
NOT SHOW ANYTHING MORE THAN THAT GIVEN THE WINDS ALOFT.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS A WEAK
COLD FRONT SLIDES THROUGH WEDNESDAY AFTERNOON FOLLOWED BY ANOTHER
AREA OF HIGH PRESSURE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS HASTINGS NE
705 AM CDT WED SEP 17 2014
.UPDATE...
ISSUED AT 705 AM CDT WED SEP 17 2014
SURE ENOUGH...LOCALLY DENSE FOG HAS GRADUALLY SHOWN ITS HAND
ACROSS MAINLY OUR NORTH CENTRAL KS ZONES...ALONG WITH PRIMARILY
OUR WESTERN-MOST COLUMN OF SOUTH CENTRAL NEBRASKA COUNTIES.
ALTHOUGH GROUND-TRUTH IS LIMITED...IT SEEMS THAT COUNTIES WITHIN
OUR CWA ARE MAINLY ON THE FRINGES OF MORE WIDESPREAD DENSE FOG
ISSUES MAINLY AFFECTING WESTERN NEB AND NORTHWEST KS. AS A
RESULT...HAVE OPTED AGAINST A FORMAL DENSE FOG ADVISORY AT THIS
TIME...BUT DID RECENTLY ISSUE A SPECIAL WEATHER STATEMENT TO
HEIGHTEN AWARENESS. IF CONDITIONS CONTINUE TO DETERIORATE THE
ONCOMING DAY SHIFT MAY HAVE TO CONSIDER A SHORT-FUSE ADVISORY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM CDT WED SEP 17 2014
THE MAIN FORECAST ISSUES DURING THESE NEXT 24 HOURS CONSIST
OF...FIRSTLY: WHETHER OR NOT POTENTIALLY IMPACTFUL FOG WILL YET
DEVELOP THIS MORNING AND IF SO...WILL IT REMAIN MOSTLY HIT-AND-
MISS OR BECOME MORE WIDESPREAD IN SOME AREAS. SECONDLY: WILL AT
LEAST ISOLATED THUNDERSTORMS FLARE UP THIS EVENING AND ESPECIALLY
LATE TONIGHT...AND IF SO COULD A FEW EVEN BECOME STRONG TO
MARGINALLY SEVERE. THIRDLY: ALTHOUGH STEADIER SURFACE BREEZES
SHOULD ACT AGAINST FOG FORMATION A BIT MORE SO ON WEDNESDAY NIGHT
VERSUS THIS MORNING...AT LEAST PATCHY DEVELOPMENT AGAIN APPEARS
POSSIBLE AS LOW LEVEL MOISTURE AGAIN KICKS UP ANOTHER NOTCH.
TEMP-WISE...ASSUMING NO UNEXPECTED ENHANCED CLOUD ISSUES...BY FAR
THE BIG STORY IS THAT HIGHS TODAY ARE FORECAST TO BREACH THE 80+
MARK NEARLY CWA-WIDE...IN MANY PLACES FOR THE FIRST TIME IN 9
DAYS SINCE SEP. 8TH...A PRETTY NOTABLE STRETCH CONSIDERING MOST OF
IT OCCURRED DURING THE FIRST HALF OF SEPTEMBER.
STARTING WITH THE HERE AND NOW AS OF 0830Z/330 AM...OVERALL
ANOTHER VERY QUIET NIGHT ACROSS THE CWA...AS ANY WINDOW OF
OPPORTUNITY FOR ELEVATED CONVECTION IN SOUTHEAST ZONES HAS ALL
BUT PASSED BY...AS SEVERAL MODELS CORRECTLY SUGGESTED THAT THIS
ACTIVITY WOULD INITIATE AND FOCUS AT LEAST A FEW COUNTIES OUTSIDE
THE AREA OVER EASTERN KS/WESTERN MO AND THIS IN FACT HAS BEEN THE
CASE. MEANWHILE...11-3.9 MICRON SATELLITE IMAGERY REVEALS NEARLY
CLOUD-FREE SKIES OVER THE CWA...ALTHOUGH A RECENTLY FORMED RIBBON
OF LOW STRATUS RACING NORTH OUT OF CENTRAL KS TOWARD SOUTHEAST NEB
APPEARS POISED TO POSSIBLY BARELY BRUSH OUR EXTREME SOUTHEAST
ZONES AS IT TRACKS NORTH-NORTHEAST. AT THE SURFACE...A RATHER
DISORGANIZED VERY LIGHT/VARIABLE WIND REGIME IS IN PLACE OVER THE
CWA...AS THE LOCAL AREA LIES WELL TO THE WEST OF THE PRIMARY RIDGE
AXIS OVER THE IL/IN AREA...AND JUST TO THE NORTH OF A VERY WEAK
LOW AND TROUGH AXIS OVER SOUTHWEST KS. AS SUSPECTED 24 HOURS
AGO...THE COMBO OF MAINLY CLEAR SKIES/LIGHT BREEZES HAS FOSTERED
AT LEAST SOME LIMITED FOG DEVELOPMENT...BUT BASED ON AUTOMATED
AIRPORT OBS AT LEAST SO FAR ANY FOG HAS BEEN PRETTY HIT AND MISS
IN NATURE AND LIKELY FAVORING TYPICAL LOW LYING AREAS VERSUS MORE
WIDESPREAD. THAT BEING SAID...A FEW AUTOMATED WITHIN OR VERY NEAR
THE CWA HAVE AT LEAST BRIEFLY REPORTED VISIBILITY UNDER 1
MILE...INCLUDING A LOCALIZED QUARTER MILE AT ORD. AS FOR LOW TEMPS
THIS MORNING...PARTS OF ESPECIALLY THE NORTHWEST HALF OF THE CWA
ARE HEADING TOWARD LOWS A FEW DEGREES COOLER THAN EXPECTED AS A
FEW SPOTS HAVE EVEN DIPPED INTO THE UPPER 40S...WHILE MUCH OF THE
SOUTHEAST HALF OF THE CWA SHOULD BOTTOM OUT LOW-MID 50S AND EVEN
CLOSER TO 60 FAR SOUTH. IN THE MID-UPPER LEVEL PICTURE...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM FAIRLY STEADY-
STATE NORTHWESTERLY FLOW OVER THE CENTRAL PLAINS...DIRECTED
BETWEEN A LARGE SCALE WESTERN CONUS RIDGE AND EASTERN CANADA
TROUGH. WELL TO THE SOUTHWEST...WEAKENING TROPICAL STORM ODILE IS
IN THE PROCESS OF SHIFTING OUT OF THE BAJA AREA TOWARD SOUTHERN
AZ. CLOSER TO HOME...A LOW AMPLITUDE DISTURBANCE ZIPPING SOUTHEAST
OVER THE NEB/IA/SD BORDER AREA TOWARD NORTHERN MO HAS HELPED
STRENGTHEN A WEST-SOUTHWESTERLY LOW LEVEL JET MAINLY OVER
KS...AND ITS NO COINCIDENCE THAT ITS EXIT REGION INTO THE KS/MO
BORDER REGION IS WHERE THE INCREASINGLY ACTIVE BAND OF MORNING
ELEVATED CONVECTION HAS FIRED UP.
LOOKING AHEAD AND NOW AND STARTING WITH THESE NEXT FEW HOURS
THROUGH AROUND SUNRISE...OBVIOUSLY FOG TRENDS ARE THE MAIN
CONCERN. ALTHOUGH FOG IS OFTEN A VERY FICKLE ENTITY...VERY SHORT
TERM VISIBILITY PROGS FROM THE RAP13 AND HRRR SUGGEST THAT THINGS
COULD CERTAINLY WORSEN/BECOME MORE WIDESPREAD YET THIS MORNING
PRIMARILY IN WESTERN AND SOUTHERN PORTIONS OF THE CWA...BUT MAYBE
ON A LOCALIZED BASIS ALMOST ANYWHERE. THINGS WOULD HAVE TO GET
CONSIDERABLE WORSE/WIDESPREAD TO EVEN BEGIN TO CONSIDER ANY KIND
OF FORMAL ADVISORY...BUT IT WILL LIKELY BE AT LEAST 14-15Z/9-10AM
BEFORE WE ARE COMPLETELY OUT OF THE WOODS ON SOME AREAS SEEING
VISIBILITIES NEAR/BELOW 1 MILE AND LOCALLY DENSE. THE BOTTOM LINE:
A MIX OF PATCHY FOG AND AREAS-OF FOG WORDING REMAINS IN THE
FORECAST FOR A FEW HOURS PAST SUNRISE...AND THESE TRENDS WILL BE
CLOSELY MONITORED.
GETTING BEYOND ANY MORNING FOG CONCERNS TO THE HEART OF THE
DAYTIME PERIOD...THE MAIN THEME HERE IS DRY CONDITIONS PERSISTING
IN THE PRESENCE OF NOTABLY WARMER CONDITIONS THAN OBSERVED LATELY.
IN THE MID-UPPER LEVELS...FAIRLY CONSISTENT AND LARGELY UNEVENTFUL
NORTHWESTERLY FLOW WILL CONTINUE OVER THE CENTRAL PLAINS AS THE
AFOREMENTIONED SUBTLE DISTURBANCE CURRENTLY JUST NORTHEAST OF THE
CWA DEPARTS WELL SOUTHEAST INTO THE OH VALLEY AREA BY DAYS END.
GIVEN THE LACK OF PERCEPTIBLE FORCING...CONFIDENCE IS RATHER HIGH
IN A DRY-DAY CWA-WIDE AS NEARLY ALL MODEL QPF AND REFLECTIVITY
FIELDS SUGGEST...AS ANY APPRECIABLE CONVECTIVE INSTABILITY THAT
MIGHT MANAGE TO BUILD SHOULD REMAIN CAPPED PER NAM FORECAST
SOUNDINGS. AT THE SURFACE...THE VERY LIGHT/VARIABLE BREEZES OF
THIS MORNING SHOULD GRADUALLY GIVE WAY TO PREVAILING EAST-
SOUTHEAST WINDS ONLY AROUND 10 MPH IN RESPONSE TO WEAK HIGH PLAINS
PRESSURE FALLS TO THE WEST. ONCE ANY MORNING LOWER STRATUS/FOG
THAT DEVELOPS BURNS OFF...SKIES SHOULD AVERAGE NO WORSE THAN
PARTLY CLOUDY DESPITE A FEW PASSING BATCHES OF MID-HIGH
CLOUDS...IN OTHER WORDS NO PESKY LOWER DAYTIME STRATUS DECK
ENVELOPING MUCH OF THE CWA DURING PEAK HEATING AS DID IN FACT
OCCUR YESTERDAY. THE OBVIOUS RESULT SHOULD BE A NOTICEABLE RISE
IN TEMPS VERSUS LATELY. THAT BEING SAID...DID NUDGE HIGHS DOWN
1-2 DEGREES FROM PREVIOUS FCST MAINLY ACROSS THE SOUTHERN CWA
WHILE LEAVING MUCH OF THE NORTH UNCHANGED. THE NET RESULT IS LOW
80S ACROSS MOST CENTRAL/NORTHEAST ZONES AND MAINLY MID 80S
SOUTHWEST WITH UPPER 80S MOST FAVORED IN FAR SOUTHWEST COUNTIES
SUCH AS ROOKS. THE AIRMASS WILL ALSO GET ANOTHER BOOST IN THE
HUMIDITY DEPARTMENT AS DEWPOINTS RISE INTO AT LEAST THE LOW 60S
MOST AREAS FOR THIS AFTERNOON.
TURNING TO THIS EVENING TONIGHT...THE BEST WAY TO DESCRIBE THINGS
IS THAT IT COULD BE A FAIRLY ACTIVE NIGHT IN PARTS OF THE CWA WITH
AT LEAST LIMITED STRONG THUNDERSTORM DEVELOPMENT AND AT LEAST
LIMITED FOG DEVELOPMENT...OR IT COULD ALMOST JUST AS EASILY BE
ANOTHER FAIRLY UNEVENTFUL NIGHT. SUCH IS THE FICKLE NATURE OF
NORTHWESTERLY-FLOW-ALOFT SITUATIONS WHEN LARGE-SCALE FORCING
REMAINS WEAK. SPEAKING OF THE MID-UPPER LEVELS...THE NORTHWESTERLY
FLOW PERSISTS BUT ACTUALLY MIGHT WEAKEN VERY SLIGHTLY AS THE MAIN
RIDGE AXIS ALIGNED OVER THE ROCKIES EDGES EVER SO SLIGHTLY FARTHER
EAST. THERE WILL UNDOUBTEDLY BE AT LEAST 1 OR 2 VERY LOW AMPLITUDE
DISTURBANCES WORKING SOUTHEASTWARD OVER/NEAR THE CWA TONIGHT...AND
COMPARED TO THIS MORNING THIS TIME AROUND IT APPEARS THERE WILL BE
MORE PRONOUNCED LOW-MID LEVEL CONVERGENCE OVER ESPECIALLY THE
SOUTHWESTERN 1/2 OF THE CWA TONIGHT AS NOTED IN 315K ISENTROPIC
SURFACE FORECASTS AND ALSO NOTED IN THE MORE WESTERLY FLOW AND
RESULTANT ELEVATED THETA-E ADVECTION BASED MAINLY IN THE 800-700MB
LAYER. PER VARIOUS DETERMINISTIC AND HIGHER-RES REFLECTIVITY MODEL
SOLUTIONS...AT LEAST A FEW THUNDERSTORMS ARE EXPECTED TO FLARE UP
ALONG THIS ELEVATED CONVERGENCE ZONE...WITH THE GREATEST
LIKELIHOOD WITHIN THE SOUTHWESTERN 1/2 OF THE CWA AFTER MIDNIGHT.
THAT BEING SAID...STORMS CANNOT BE COMPLETELY BE RULED OUT BEFORE
MIDNIGHT EITHER AND HAVE MAINTAINED SOME 20 POPS IN SOUTHWESTERN
AREAS DURING THE EVENING WHILE EXPANDING AT LEAST 20 POPS TO ALL
AREAS AFTER MIDNIGHT BUT FOCUSING HIGHEST 30S IN SOUTHERN ZONES.
SHOULD CONVECTION MATERIALIZE...CERTAINLY A FEW STRONG STORMS
CAPABLE OF PRODUCING HAIL TO AT LEAST NICKEL SIZE OR SLIGHTLY
LARGER CANNOT BE RULED OUT GIVEN ELEVATED CAPE OF 1000-1500 J/KG
IN THE PRESENCE OF AROUND 40KT OF DEEP LAYER SHEAR. MEANWHILE AT
THE SURFACE...FAIRLY LIGHT BUT STEADY EASTERLY BREEZES GENERALLY
5-10 MPH SHOULD PERSIST OVERNIGHT...WHICH SHOULD HELP WORK AGAINST
ANY WIDESPREAD/IMPACTFUL FOG FORMATION...ALONG WITH OF COURSE ANY
LOCALIZED MIXING FROM CONVECTIVE ACTIVITY. THAT BEING SAID...AT
LEAST PATCHY LIGHT FOG CERTAINLY CANNOT BE RULED OUT IN THE MOIST
EASTERLY FLOW...SO HAVE INTRODUCED PATCHY FOG TO THE LATE NIGHT
FORECAST. THE EARLIER 00Z NAM SUGGESTED THAT POTENTIALLY
WIDESPREAD LOW STRATUS AND POSSIBLE LIGHT DRIZZLE COULD
MATERIALIZE AS WELL...BUT THE LATEST 06Z NAM SUGGESTS THAT LOW
LEVEL MOISTURE DEPTH WILL LIKELY REMAIN INSUFFICIENT FOR DRIZZLE
PRODUCTION. MADE VERY LITTLE ALTERATION TO LOW TEMPERATURES...AS
ANOTHER UPWARD CLIMB FROM ONE NIGHT TO THE NEXT CONTINUES...WITH
LOWS AIMED FROM THE UPPER 50S NORTH...LOW 60S CENTRAL AND MID 60S
SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED SEP 17 2014
SUMMARY...FRIDAY...WITH HIGHS IN THE MID 80S...STILL APPEARS TO THE
BE THE WARMEST DAY OF THE NEXT 7 DAYS FOR MOST AREAS...ALTHOUGH IT
WILL NOT BE ALL THAT MUCH WARMER THAN TODAY. RAIN CHANCES IN THE
EXTENDED PERIOD ARE NOT THAT GOOD AND CHANCES HAVE EVEN FALLEN OFF A
LITTLE BIT DURING THE PERIODS WHERE 24HRS EARLIER THEY LOOKING THE
BEST...FRIDAY NIGHT INTO SATURDAY. OVERALL IT WILL BE A FAIRLY
TYPICAL MID SEPTEMBER PERIOD WITH HIGHS ON MOST DAYS AVERAGING OUT
IN THE 70S TO AROUND 80.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES SHOULD DECREASE. THERE IS
WEAK ISENTROPIC LIFT IN THE LOWEST LAYER FROM AROUND AND BELOW 850
MB AND FORECAST MODELS INDICATE THAT A LOW STRATUS DECK COULD
PERSIST THROUGH MUCH OF THE DAY. INITIALLY THIS STRATUS DECK MAY BE
LOW ENOUGH TO BE FOG RIGHT AFTER SUNRISE. SOME FORECAST MODELS ARE
TRYING TO GENERATE A HUNDREDTH OR TWO OF SPLOTCHY QPF. TYPICALLY
THIS COULD BE SPRINKLES...DRIZZLE...OR EVEN ISOLATED THUNDERSTORMS.
IN THIS CASE THE FORECAST SOUNDINGS INDICATE THAT THE SATURATED
STRATUS DECK WILL BE BELOW 850 MB AND NOT THICK ENOUGH TO PRODUCE
DRIZZLE. THERE COULD BE SOME CLOUD SEEDING FROM PASSING MID CLOUDS
GENERATING A FEW SPRINKLES...BUT MOST AREAS WILL BE DRY. THERE IS
SOME WEAK INSTABILITY SO WE CAN NOT RULE OUT THUNDERSTORMS...BUT
ODDS OF THUNDER ARE LOW ENOUGH TO CONTINUE TO KEEP IT OUT OF THE
FORECAST FOR NOW. THE STRATUS DECK WILL KEEP TEMPERATURES DOWN
ESPECIALLY ACROSS NEBRASKA ZONES WHERE STRATUS WILL LIKELY LINGER
LONGER. HIGHS WILL RANGE FROM THE MID 70S IN THE TRI CITIES TO THE
MID 80S ACROSS OUR SOUTHWEST KANSAS COUNTIES.
THURSDAY NIGHT INTO FRIDAY AFTERNOON...THERE IS GOOD AGREEMENT IN
NUMEROUS FORECAST MODELS AND MODEL BLENDS THAT THIS WILL BE A DRY
PERIOD ACROSS OUR FORECAST AREA. THE REMNANTS OF HURRICANE ODILE WILL
BE HEADING NORTHEAST INTO THE TEXAS PANHANDLE AND POSSIBLY INTO FAR
SOUTHWEST KANSAS BY FRIDAY AFTERNOON...BUT STILL OUTSIDE OF OUR
FORECAST AREA. AN UPPER TROUGH COMING OUT OF THE NORTHERN STREAM
WILL BE BREAKING OFF A VORT MAX OVER CALIFORNIA RESULTING IN A LESS
VIGOROUS WAVE FOR OUR FORECAST AREA THAN WAS INDICATED IN MODEL RUNS
24HRS AGO.
FRIDAY NIGHT INTO SATURDAY...THE UPPER TROUGH SWINGING THROUGH THE
PLAINS IS LOOKING LESS IMPRESSIVE WITH RECENT FORECAST RUNS AS SOME
OF THE ENERGY IS BEING LEFT BEHIND OVER CALIFORNIA WHERE IT LEAVES
BEHIND A CUT OFF LOW. MODEL BLENDS HAVE REDUCED POPS SOME IN THIS
PERIOD...AND IT SEEMS JUSTIFIED GIVEN THE SYNOPTIC SITUATION. WILL
HAVE TO REALLY KEEP AN EYE ON THE REMNANTS OF ODILE DURING THIS
PERIOD AS THE REMAINING VORT MAX AND MOISTURE WILL BE COMING UP
THROUGH KANSAS AND MIGHT BE FAR ENOUGH NORTH TO IMPACT OUR CWA.
HOWEVER...THE BETTER BET AT THIS TIME FOR ODILE RELATED
MOISTURE/RAINFALL WILL BE JUST TO THE SOUTH OF OUR FORECAST AREA.
SUNDAY THROUGH TUESDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH GENERALLY DRY WEATHER LIKELY FOR OUR FORECAST
AREA. CAN NOT COMPLETELY RULE OUT A SHORT WAVE SLIDING DOWN INTO OUR
FORECAST AREA ON THE EAST SIDE OF THE RIDGE BY TUESDAY...BUT MOST
AREAS APPEAR DRY AT THIS TIME. HIGH TEMPERATURES WILL BE NEAR NORMAL
AVERAGING OUT IN THE 70S.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH THURSDAY MORNING)
ISSUED AT 700 AM CDT WED SEP 17 2014
ALTHOUGH CONFIDENCE IS FAIRLY HIGH IN VFR CEILING/VISIBILITY
THROUGH THE MIDDLE 12-18 HOURS OF THE VALID PERIOD...THERE IS
QUITE A BIT UNCERTAINTY REGARDING BOTH THE INITIAL FEW HOURS RIGHT
AWAY THIS MORNING...AND THEN AGAIN LATE TONIGHT. IN
ADDITION...THERE IS AT LEAST A LOW RISK FOR SHOWERS/THUNDERSTORMS
AT ONE OR BOTH TERMINALS ESPECIALLY DURING THE OVERNIGHT
HOURS...BUT CONFIDENCE IN OCCURRENCE IS STILL TOO LOW AT THIS TIME
RANGE TO EVEN JUSTIFY A VICINITY THUNDERSTORM (VCTS). STARTING
WITH THE FIRST FEW HOURS THIS MORNING...THERE IS STILL A CHANCE
THAT AT LEAST LIGHT FOG AND OR BRIEF LOW STRATUS COULD MOVE INTO
THE AREA...BUT IT HAS REMAINED AT LEAST SLIGHTLY WEST AND/OR SOUTH
OF THE AREA THUS FAR. GIVEN CONSIDERABLE UNCERTAINTY...WILL RUN A
TEMPO GROUP FOR MVFR VISIBILITY WITH AMENDMENTS VERY POSSIBLE.
ONCE ANY MORNING FOG/STRATUS BURNS...SEVERAL HOURS OF
HIGH-CONFIDENCE VFR COMMENCES. THEN LATE TONIGHT...MOIST EASTERLY
FLOW COULD SPARK ANOTHER ROUND OF STRATUS AND FOG...AND HAVE
INTRODUCED MVFR CATEGORIES IN EACH STARTING AT 08Z. SURFACE
BREEZES SHOULD NOT BE MUCH OF AN ISSUE THROUGH THE PERIOD...WITH
SUSTAINED SPEEDS AVERAGING UNDER 10KT AND FROM AN EAST-SOUTHEAST
DIRECTION THROUGH MOST OF THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
610 AM MDT WED SEP 17 2014
.AVIATION...
12Z TAF CYCLE
AN ORGANIZED BAND OF PCPN SHOULD CONTINUE TO SHIFT SLOWLY N AND NEWD
FROM THE LOWER RIO GRANDE VALLEY ACROSS CENTRAL AND E PARTS OF THE
FORECAST AREA THOUGH MID DAY AND INTO THE EARLY AFTN. THIS WILL
BRING LIGHT TO MDT RAIN WITH RISK OF MVFR CEILINGS TO AIRPORTS
LIKE KABQ...KSAF...KLVS...KSRR...AND POSSIBLY KTCC. THE HIGH
RESOLUTION RAPID REFRESH MODEL SEEMS TO HAVE PICKED UP ON THIS
BAND...AND SUGGESTS SCT TO ISOLD THUNDERSTORMS MAY DEVELOP IN ITS
WAKE MAINLY EAST OF THE CENTRAL MT CHAIN. KROW LOOKS TO BE A BIT
TOO SE OF THIS BAND FOR MUCH PRECIP...BUT RUNS THE RISK OF IFR AND
LIFR CONDITIONS UNTIL LATE MORNING. THUNDERSTORMS COULD REACH KROW
TOO IN THE AFTN. OTHERWISE...WDSPR MT OBSCURATIONS ARE EXPECTED
TODAY. MODELS SUGGEST ANOTHER ORGANIZED BAND OF PRECIPITATION WITH
MVFR AND POSSIBLY IFR CONDITIONS WILL IMPACT AREAS S OF I-40
TONIGHT.
44
&&
.PREV DISCUSSION...406 AM MDT WED SEP 17 2014...
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ODILE WILL CONTINUE TO IMPACT THE
AREA THE REMAINDER OF THE WORK WEEK. RAIN AND EMBEDDED THUNDERSTORMS
WILL BE MOST WIDESPREAD ACROSS CENTRAL AND SOUTHERN AREAS THROUGH
TONIGHT...EXPANDING NORTHEASTWARD AND INTENSIFYING THURSDAY INTO
THURSDAY NIGHT AS THE CORE OF THE REMNANT LOW PASSES OVER THE
HEART OF THE STATE. THE THREAT OF AREAL FLOODING AND POTENTIALLY
LIFE-THREATENING FLASH FLOODING WILL BE GREATEST IN THE SOUTHWESTERN
AND SOUTH CENTRAL MOUNTAINS AND ADJACENT HIGHLANDS BUT LOCALIZED
FLASH FLOODING WILL BE A THREAT AREAWIDE. A SLOW AND GRADUAL
DRYING AND CLEARING TREND IS EXPECTED IN WESTERN NEW MEXICO ON
FRIDAY...BUT EASTERN SECTIONS OF THE STATE COULD CONTINUE TO SEE
SHOWERS AND THUNDERSTORMS WITH A LOCALLY HEAVY RAINFALL THREAT.
FOLLOWING A BRIEF BREAK IN THE SHOWER PATTERN SATURDAY...AN ACTIVE
PATTERN RETURNS EARLY NEXT WEEK.
&&
.DISCUSSION...
ONLY CHANGES TO PREVIOUS FLASH FLOOD WATCH WAS TO EXTEND IT THROUGH
THURSDAY...AND TO ADD THE REMAINDER OF CHAVES COUNTY. FURTHER TIME
AND AREAL EXTENSIONS CAN BE EXPECTED BY LATER SHIFTS TO COVER THURSDAY
NIGHT INTO FRIDAY AS THE EVENT CONTINUES TO UNFOLD.
PER NHC 3AM MDT UPDATE...THE CENTER OF ODILE WAS ABOUT 85 MILES
SOUTH OF PUERTO PENASCO MX AND SLOWLY MOVING NNE AT 6 MPH. A TURN
TOWARD THE NE IS EXPECTED TODAY AS THE TROPICAL CYCLONE RAPIDLY
WEAKENS OVER LAND. THAT PROCESS MAY BE UNDER WAY ALREADY THIS
MORNING WITH EVIDENCE IN WATER VAPOR/INFRARED SATELLITE IMAGERY
THAT THE MID/UPPER CIRCULATION IS BEGINNING TO GET INCREASINGLY SHEARED
NEWD.
THE OFFICIAL TRACK BRINGS THE REMNANT CIRCULATION CLOSE TO TUCSON
LATE THIS EVENING AND THEN INTO OUR SW ZONES SOMETIME THURSDAY
MORNING. THE GFS AND ECMWF ARE PRETTY CLOSE SHOWING THE REMNANT
CIRCULATION OVER CATRON COUNTY NEAR THE NM/AZ LINE BY MIDDAY
THURSDAY. THEREAFTER...SIGNIFICANT TRENDING DIFFERENCES CONTINUE WITH
THE ECMWF KEEPING A BROAD BUT WELL- DEFINED LOW CENTER BETWEEN
FARMINGTON AND ALBUQUERQUE WHILE THE GFS...WHICH APPEARS TO
SUFFER FROM CONVECTIVE FEEDBACK ISSUES IN LATER PERIODS...GENERALLY
DRIVES THE REMNANT CIRCULATION MORE EASTERLY THAN NELY. TRACKING
THE CORE OF THIS REMNANT CIRCULATION WILL BE CRITICAL AS IT WILL
GENERATE TREMENDOUS RAINFALL RATES AS IT CONTRACTS AND INTERACTS
WITH THE COMPLEX TERRAIN OF WC/SW NEW MEXICO. POTENTIAL FOR LIFE-
THREATENING FLOODING/FLASH FLOODING WILL BE GREATEST FOR THE GILA AS WELL
AS BURN SCARS ACROSS LINCOLN COUNTY...BUT THE POTENTIAL FOR
SERIOUS FLASH FLOODING WILL EXIST THROUGH OUT THE CURRENT WATCH
AREA PARTICULARLY LOWLAND AREAS OF SOCORRO/CATRON COUNTIES THAT
HAVE ALREADY RECEIVED SIGNIFICANT RAINFALL.
MEANWHILE...POP PLACEMENT FOR WEST-CENTRAL...MIDDLE RIO GRANDE VALLEY AND
NEIGHBORING CENTRAL HIGHLAND ZONES CONTINUES TO BE CHALLENGING AS
PRECIP BANDS MIGRATING NORTHWARD SEEM TO BE STRUGGLING BENEATH A
BROADLY CONFLUENT FLOW ALOFT. THE LATEST HRRR IS QUITE BULLISH ON
PROSPECT FOR THE ABOVE MENTIONED AREAS AND ESPECIALLY TOWARD
GRANTS/GALLUP AND TRENDED POP UPWARD CLOSER TO MAV GUIDANCE.
OTHERWISE...NOT CONVINCED WE WILL SEE WIDESPREAD/NUMEROUS
THUNDERSTORM ACTIVITY OVER SC/SW ZONES TODAY GIVEN THE LACK OF
STRONG SURFACE HEATING/INSTABILITY BUT THE WRF/HRRR DO SUGGEST A
SIGNIFICANT INCREASE IN CONVECTIVE PRECIP FOR THE SE PLAINS LATER
TODAY/EVENING.
LINGERING TROPICAL MOISTURE AND MORE SUNSHINE MAY SPELL A MORE
ACTIVE DAY ON FRIDAY ACROSS THE CENTRAL/WEST THAN CURRENTLY
ADVERTISED BUT TRENDING LESS ACTIVE BY SATURDAY BEFORE NEXT UPTICK
IN SHOWER/STORM COVERAGE SUNDAY/MONDAY. SEE BELOW FOR A MORE DETAILED
EXTENDED ANALYSIS. KJ
&&
.FIRE WEATHER...
MODELS CONTINUE TO HAVE GOOD AGREEMENT ON THE REMNANTS OF NOW
TROPICAL STORM ODILE TRACKING NORTHEASTWARD FROM THE UPPER GULF OF
CALIFORNIA ACROSS THE FIRE WEATHER FORECAST AREA TODAY THROUGH
FRIDAY. ONCE THE SYSTEM BECOMES EXTRATROPICAL...THE CENTER OF UPPER
LEVEL LOW PRESSURE IS PROGGED TO TRACK NORTHEASTWARD OVER TUCSON
TONIGHT...GALLUP THURSDAY...THEN CHAMA/TAOS ON FRIDAY. THIS WILL
PLACE SOUTHWEST/WEST CENTRAL...CENTRAL...THEN NORTHEAST PARTS OF THE
FORECAST AREA UNDER ROBUST DYNAMICS FOR LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE FOREBODING PRECIPITATION FORECAST FROM THE
WEATHER PREDICTION CENTER CALLS FOR AN ADDITIONAL 2 TO 6 INCHES OF
RAIN FROM THE GALLINAS MOUNTAINS WESTWARD ACROSS SOCORRO COUNTY AND
THE WEST CENTRAL HIGHLANDS. AMOUNTS TREND GRADUALLY DOWNWARD NORTH
AND NORTHEASTWARD WITH 1 INCH ACCUMULATIONS POSSIBLE AS FAR NORTH AS THE
SOUTHERN CHUSKAS...THE BRAZOS AND CLAYTON. EXCEPT FOR THE FOUR
CORNERS REGION...THE WHOLE FORECAST AREA HAS A GOOD SHOT OF WETTING
PRECIPITATION THIS WEEK. IT MAY TAKE TIL THURSDAY NIGHT AND FRIDAY
FOR SIGNIFICANT PRECIP TO REACH THE NORTHERN BORDER.
IN THE WAKE OF ODILES REMNANTS MODELS AGREE BETTER ON AN UPPER LEVEL
LOW PRESSURE SYSTEM STALLING OFF THE CA COAST FRIDAY NIGHT AND
SATURDAY. THEY THEN DIVERGE IN TRACK AND TIMING WITH THE STORM EJECTING
NORTHEASTWARD EITHER ACROSS THE CENTRAL OR NORTHERN ROCKIES LATE IN
THE WEEKEND AND EARLY IN THE COMING WEEK. HOWEVER...MODELS DO
GENERALLY AGREE ON THE SYSTEM DRAWING A BACK DOOR COLD FRONT INTO
THE FORECAST AREA FROM THE NE FRIDAY NIGHT AND INTO AZ SATURDAY
NIGHT. THIS MAY RESULT IN A FAIRLY STRONG EAST CANYON WIND IN THE
RIO GRANDE VALLEY SATURDAY NIGHT. HUMIDITIES SHOULD TREND DOWNWARD
BY 10 TO 20 PERCENT ON SATURDAY...ONLY TO REBOUND A FEW TO 16
PERCENT ON SUNDAY BEHIND THE COLD FRONT. WITH THE DECREASE IN
MOISTURE THERE WILL BE A SIGNIFICANT DOWNTICK IN THUNDERSTORM
COVERAGE ON SATURDAY. THEN...THE CHANCE FOR THUNDERSTORMS WILL TREND
UPWARD AGAIN SUNDAY INTO THE COMING WORK WEEK AS THE UPPER LOW
PASSING NORTH OF NM DRAWS A ROBUST MONSOON MOISTURE PLUME NORTHWARD
OVER THE STATE. AT THIS TIME...CENTRAL AND WESTERN AREAS LOOK
FAVORED FOR WETTING THUNDERSTORM CHANCES SUNDAY AND MONDAY. THE
MOISTURE PLUME MAY THEN FAVOR CENTRAL AND EASTERN AREAS FOR WETTING
PRECIPITATION TUESDAY...DEPENDING ON THE TRACK OF THE UPPER LOW AND
HOW QUICKLY IT EXITS THE ROCKIES ONTO THE PLAINS.
WITH BANDS OF PRECIPITATION LIKELY TO TRACK NORTHWARD INTO THE
FORECAST AREA TODAY AND THURSDAY...HIGH TEMPERATURES SHOULD VARY A
FEW TO 11 DEGREES BELOW NORMAL. NEAR TO ABOVE NORMAL READINGS ARE
EXPECTED ALONG THE NORTHERN BORDER. LOW TEMPERATURES DURING THIS
PERIOD SHOULD REMAIN ABOVE NORMAL DUE TO GENERALLY SOUTHERLY FLOW
AND OVERNIGHT CLOUD COVER. TEMPERATURES SHOULD BEGIN TO REBOUND
TOWARD NORMAL ON FRIDAY...EXCEPT PERHAPS ACROSS THE EAST WHERE SOME
OF THE BETTER SUBTROPICAL MOISTURE MAY LINGER. HIGH TEMPS SHOULD
THEN REACH NEAR AND ABOVE NORMAL AREAWIDE ON SATURDAY...ONLY TO DROP
AGAIN ON SUNDAY IN THE WAKE OF THE COLD FRONT.
IN ADDITION...POCKETS OF POOR VENTILATION ARE FORECAST
TODAY...FRIDAY...MONDAY AND TUESDAY...WITH SOME IMPROVEMENT
THURSDAY...SATURDAY AND SUNDAY. MEAGER HAINES VALUES ARE ALSO
EXPECTED OVER THE NEXT 7 DAYS. 44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ508-509-520-524>526-539-540.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ538.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
406 AM MDT WED SEP 17 2014
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ODILE WILL CONTINUE TO IMPACT THE
AREA THE REMAINDER OF THE WORK WEEK. RAIN AND EMBEDDED THUNDERSTORMS
WILL BE MOST WIDESPREAD ACROSS CENTRAL AND SOUTHERN AREAS THROUGH
TONIGHT...EXPANDING NORTHEASTWARD AND INTENSIFYING THURSDAY INTO
THURSDAY NIGHT AS THE CORE OF THE REMNANT LOW PASSES OVER THE
HEART OF THE STATE. THE THREAT OF AREAL FLOODING AND POTENTIALLY
LIFE-THREATENING FLASH FLOODING WILL BE GREATEST IN THE SOUTHWESTERN
AND SOUTH CENTRAL MOUNTAINS AND ADJACENT HIGHLANDS BUT LOCALIZED
FLASH FLOODING WILL BE A THREAT AREAWIDE. A SLOW AND GRADUAL
DRYING AND CLEARING TREND IS EXPECTED IN WESTERN NEW MEXICO ON
FRIDAY...BUT EASTERN SECTIONS OF THE STATE COULD CONTINUE TO SEE
SHOWERS AND THUNDERSTORMS WITH A LOCALLY HEAVY RAINFALL THREAT.
FOLLOWING A BRIEF BREAK IN THE SHOWER PATTERN SATURDAY...AN ACTIVE
PATTERN RETURNS EARLY NEXT WEEK.
&&
.DISCUSSION...
ONLY CHANGES TO PREVIOUS FLASH FLOOD WATCH WAS TO EXTEND IT THROUGH
THURSDAY...AND TO ADD THE REMAINDER OF CHAVES COUNTY. FURTHER TIME
AND AREAL EXTENSIONS CAN BE EXPECTED BY LATER SHIFTS TO COVER THURSDAY
NIGHT INTO FRIDAY AS THE EVENT CONTINUES TO UNFOLD.
PER NHC 3AM MDT UPDATE...THE CENTER OF ODILE WAS ABOUT 85 MILES
SOUTH OF PUERTO PENASCO MX AND SLOWLY MOVING NNE AT 6 MPH. A TURN
TOWARD THE NE IS EXPECTED TODAY AS THE TROPICAL CYCLONE RAPIDLY
WEAKENS OVER LAND. THAT PROCESS MAY BE UNDER WAY ALREADY THIS
MORNING WITH EVIDENCE IN WATER VAPOR/INFRARED SATELLITE IMAGERY
THAT THE MID/UPPER CIRCULATION IS BEGINNING TO GET INCREASINGLY SHEARED
NEWD.
THE OFFICIAL TRACK BRINGS THE REMNANT CIRCULATION CLOSE TO TUCSON
LATE THIS EVENING AND THEN INTO OUR SW ZONES SOMETIME THURSDAY
MORNING. THE GFS AND ECMWF ARE PRETTY CLOSE SHOWING THE REMNANT
CIRCULATION OVER CATRON COUNTY NEAR THE NM/AZ LINE BY MIDDAY
THURSDAY. THEREAFTER...SIGNIFICANT TRENDING DIFFERENCES CONTINUE WITH
THE ECMWF KEEPING A BROAD BUT WELL- DEFINED LOW CENTER BETWEEN
FARMINGTON AND ALBUQUERQUE WHILE THE GFS...WHICH APPEARS TO
SUFFER FROM CONVECTIVE FEEDBACK ISSUES IN LATER PERIODS...GENERALLY
DRIVES THE REMNANT CIRCULATION MORE EASTERLY THAN NELY. TRACKING
THE CORE OF THIS REMNANT CIRCULATION WILL BE CRITICAL AS IT WILL
GENERATE TREMENDOUS RAINFALL RATES AS IT CONTRACTS AND INTERACTS
WITH THE COMPLEX TERRAIN OF WC/SW NEW MEXICO. POTENTIAL FOR LIFE-
THREATENING FLOODING/FLASH FLOODING WILL BE GREATEST FOR THE GILA AS WELL
AS BURN SCARS ACROSS LINCOLN COUNTY...BUT THE POTENTIAL FOR
SERIOUS FLASH FLOODING WILL EXIST THROUGH OUT THE CURRENT WATCH
AREA PARTICULARLY LOWLAND AREAS OF SOCORRO/CATRON COUNTIES THAT
HAVE ALREADY RECEIVED SIGNIFICANT RAINFALL.
MEANWHILE...POP PLACEMENT FOR WEST-CENTRAL...MIDDLE RIO GRANDE VALLEY AND
NEIGHBORING CENTRAL HIGHLAND ZONES CONTINUES TO BE CHALLENGING AS
PRECIP BANDS MIGRATING NORTHWARD SEEM TO BE STRUGGLING BENEATH A
BROADLY CONFLUENT FLOW ALOFT. THE LATEST HRRR IS QUITE BULLISH ON
PROSPECT FOR THE ABOVE MENTIONED AREAS AND ESPECIALLY TOWARD
GRANTS/GALLUP AND TRENDED POP UPWARD CLOSER TO MAV GUIDANCE.
OTHERWISE...NOT CONVINCED WE WILL SEE WIDESPREAD/NUMEROUS
THUNDERSTORM ACTIVITY OVER SC/SW ZONES TODAY GIVEN THE LACK OF
STRONG SURFACE HEATING/INSTABILITY BUT THE WRF/HRRR DO SUGGEST A
SIGNIFICANT INCREASE IN CONVECTIVE PRECIP FOR THE SE PLAINS LATER
TODAY/EVENING.
LINGERING TROPICAL MOISTURE AND MORE SUNSHINE MAY SPELL A MORE
ACTIVE DAY ON FRIDAY ACROSS THE CENTRAL/WEST THAN CURRENTLY
ADVERTISED BUT TRENDING LESS ACTIVE BY SATURDAY BEFORE NEXT UPTICK
IN SHOWER/STORM COVERAGE SUNDAY/MONDAY. SEE BELOW FOR A MORE DETAILED
EXTENDED ANALYSIS. KJ
&&
.FIRE WEATHER...
MODELS CONTINUE TO HAVE GOOD AGREEMENT ON THE REMNANTS OF NOW
TROPICAL STORM ODILE TRACKING NORTHEASTWARD FROM THE UPPER GULF OF
CALIFORNIA ACROSS THE FIRE WEATHER FORECAST AREA TODAY THROUGH
FRIDAY. ONCE THE SYSTEM BECOMES EXTRATROPICAL...THE CENTER OF UPPER
LEVEL LOW PRESSURE IS PROGGED TO TRACK NORTHEASTWARD OVER TUCSON
TONIGHT...GALLUP THURSDAY...THEN CHAMA/TAOS ON FRIDAY. THIS WILL
PLACE SOUTHWEST/WEST CENTRAL...CENTRAL...THEN NORTHEAST PARTS OF THE
FORECAST AREA UNDER ROBUST DYNAMICS FOR LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE FOREBODING PRECIPITATION FORECAST FROM THE
WEATHER PREDICTION CENTER CALLS FOR AN ADDITIONAL 2 TO 6 INCHES OF
RAIN FROM THE GALLINAS MOUNTAINS WESTWARD ACROSS SOCORRO COUNTY AND
THE WEST CENTRAL HIGHLANDS. AMOUNTS TREND GRADUALLY DOWNWARD NORTH
AND NORTHEASTWARD WITH 1 INCH ACCUMULATIONS POSSIBLE AS FAR NORTH AS THE
SOUTHERN CHUSKAS...THE BRAZOS AND CLAYTON. EXCEPT FOR THE FOUR
CORNERS REGION...THE WHOLE FORECAST AREA HAS A GOOD SHOT OF WETTING
PRECIPITATION THIS WEEK. IT MAY TAKE TIL THURSDAY NIGHT AND FRIDAY
FOR SIGNIFICANT PRECIP TO REACH THE NORTHERN BORDER.
IN THE WAKE OF ODILES REMNANTS MODELS AGREE BETTER ON AN UPPER LEVEL
LOW PRESSURE SYSTEM STALLING OFF THE CA COAST FRIDAY NIGHT AND
SATURDAY. THEY THEN DIVERGE IN TRACK AND TIMING WITH THE STORM EJECTING
NORTHEASTWARD EITHER ACROSS THE CENTRAL OR NORTHERN ROCKIES LATE IN
THE WEEKEND AND EARLY IN THE COMING WEEK. HOWEVER...MODELS DO
GENERALLY AGREE ON THE SYSTEM DRAWING A BACK DOOR COLD FRONT INTO
THE FORECAST AREA FROM THE NE FRIDAY NIGHT AND INTO AZ SATURDAY
NIGHT. THIS MAY RESULT IN A FAIRLY STRONG EAST CANYON WIND IN THE
RIO GRANDE VALLEY SATURDAY NIGHT. HUMIDITIES SHOULD TREND DOWNWARD
BY 10 TO 20 PERCENT ON SATURDAY...ONLY TO REBOUND A FEW TO 16
PERCENT ON SUNDAY BEHIND THE COLD FRONT. WITH THE DECREASE IN
MOISTURE THERE WILL BE A SIGNIFICANT DOWNTICK IN THUNDERSTORM
COVERAGE ON SATURDAY. THEN...THE CHANCE FOR THUNDERSTORMS WILL TREND
UPWARD AGAIN SUNDAY INTO THE COMING WORK WEEK AS THE UPPER LOW
PASSING NORTH OF NM DRAWS A ROBUST MONSOON MOISTURE PLUME NORTHWARD
OVER THE STATE. AT THIS TIME...CENTRAL AND WESTERN AREAS LOOK
FAVORED FOR WETTING THUNDERSTORM CHANCES SUNDAY AND MONDAY. THE
MOISTURE PLUME MAY THEN FAVOR CENTRAL AND EASTERN AREAS FOR WETTING
PRECIPITATION TUESDAY...DEPENDING ON THE TRACK OF THE UPPER LOW AND
HOW QUICKLY IT EXITS THE ROCKIES ONTO THE PLAINS.
WITH BANDS OF PRECIPITATION LIKELY TO TRACK NORTHWARD INTO THE
FORECAST AREA TODAY AND THURSDAY...HIGH TEMPERATURES SHOULD VARY A
FEW TO 11 DEGREES BELOW NORMAL. NEAR TO ABOVE NORMAL READINGS ARE
EXPECTED ALONG THE NORTHERN BORDER. LOW TEMPERATURES DURING THIS
PERIOD SHOULD REMAIN ABOVE NORMAL DUE TO GENERALLY SOUTHERLY FLOW
AND OVERNIGHT CLOUD COVER. TEMPERATURES SHOULD BEGIN TO REBOUND
TOWARD NORMAL ON FRIDAY...EXCEPT PERHAPS ACROSS THE EAST WHERE SOME
OF THE BETTER SUBTROPICAL MOISTURE MAY LINGER. HIGH TEMPS SHOULD
THEN REACH NEAR AND ABOVE NORMAL AREAWIDE ON SATURDAY...ONLY TO DROP
AGAIN ON SUNDAY IN THE WAKE OF THE COLD FRONT.
IN ADDITION...POCKETS OF POOR VENTILATION ARE FORECAST
TODAY...FRIDAY...MONDAY AND TUESDAY...WITH SOME IMPROVEMENT
THURSDAY...SATURDAY AND SUNDAY. MEAGER HAINES VALUES ARE ALSO
EXPECTED OVER THE NEXT 7 DAYS. 44
&&
.AVIATION...
06Z TAF CYCLE
TROPICAL STORM ODILE REMNANTS OVER THE NORTHERN GULF OF CALIFORNIA
WILL DRIFT INTO SOUTHEAST ARIZONA OVER THE NEXT 24 HOURS KEEPING
MOUNTAINS OBSCURED AND WIDESPREAD CLOUD COVER IN PLAY. HEAVIEST
RAINFALL WILL SET UP OVER SOUTHERN HALF OF NEW MEXICO...WITH ONLY
SPOTTY SHOWER COVERAGE TO THE NORTH. HAVE VCSH CARRIED IN TAFS TO
COVER EXPECTED PERIOD OF SHOWER COVERAGE...WITH SCT LAYERS
PLACE HOLDING FOR POSSIBLE EXCURSIONS INTO IFR/MVFR CIGS IN HEAVIER
SHOWERS. ROW CURRENTLY IN FOG WILL BATTLE LOW VIZ OVERNIGHT...WITH
VIZ IMPROVING FROM 17Z ONWARD WED MORNING.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 82 56 80 60 / 20 20 10 20
DULCE........................... 81 46 78 51 / 40 30 20 40
CUBA............................ 74 50 75 53 / 60 20 40 50
GALLUP.......................... 74 52 72 55 / 60 50 60 40
EL MORRO........................ 67 49 66 52 / 60 70 80 60
GRANTS.......................... 71 53 69 54 / 60 50 80 60
QUEMADO......................... 70 52 65 53 / 80 90 90 60
GLENWOOD........................ 72 57 68 58 / 80 100 100 60
CHAMA........................... 75 43 73 47 / 40 20 30 40
LOS ALAMOS...................... 75 52 72 54 / 40 20 40 60
PECOS........................... 73 52 68 54 / 40 30 50 60
CERRO/QUESTA.................... 76 45 73 49 / 30 20 20 30
RED RIVER....................... 67 43 65 45 / 30 10 20 40
ANGEL FIRE...................... 73 41 69 47 / 30 20 30 50
TAOS............................ 77 47 73 51 / 30 20 10 30
MORA............................ 73 49 69 52 / 30 20 40 60
ESPANOLA........................ 80 54 77 57 / 30 20 20 40
SANTA FE........................ 74 53 71 55 / 40 30 40 60
SANTA FE AIRPORT................ 77 54 73 56 / 40 30 50 60
ALBUQUERQUE FOOTHILLS........... 72 57 72 59 / 60 30 70 70
ALBUQUERQUE HEIGHTS............. 74 60 72 61 / 60 40 70 70
ALBUQUERQUE VALLEY.............. 76 58 74 60 / 60 40 70 70
ALBUQUERQUE WEST MESA........... 76 59 75 60 / 60 30 70 60
LOS LUNAS....................... 76 59 73 61 / 60 50 70 70
RIO RANCHO...................... 75 60 76 60 / 50 30 60 60
SOCORRO......................... 71 60 73 61 / 80 80 80 70
SANDIA PARK/CEDAR CREST......... 75 53 72 56 / 50 30 70 80
TIJERAS......................... 75 54 72 57 / 60 40 70 70
MORIARTY/ESTANCIA............... 74 52 69 55 / 60 40 70 70
CLINES CORNERS.................. 71 54 66 55 / 50 30 70 80
GRAN QUIVIRA.................... 69 55 66 57 / 80 60 90 70
CARRIZOZO....................... 69 59 69 59 / 80 70 80 70
RUIDOSO......................... 64 53 64 55 / 80 80 100 80
CAPULIN......................... 82 49 77 53 / 5 10 10 30
RATON........................... 83 49 79 54 / 5 10 10 30
SPRINGER........................ 84 50 78 55 / 10 10 20 40
LAS VEGAS....................... 75 50 70 54 / 30 20 40 60
CLAYTON......................... 86 58 82 59 / 5 5 10 20
ROY............................. 81 54 75 57 / 20 10 30 40
CONCHAS......................... 84 61 77 62 / 20 20 40 50
SANTA ROSA...................... 80 59 72 60 / 30 20 50 60
TUCUMCARI....................... 84 60 78 63 / 20 20 30 40
CLOVIS.......................... 78 61 73 62 / 40 30 50 50
PORTALES........................ 78 61 72 63 / 50 40 50 50
FORT SUMNER..................... 78 61 71 62 / 40 30 60 50
ROSWELL......................... 75 64 72 65 / 60 60 70 70
PICACHO......................... 70 60 68 60 / 70 60 80 80
ELK............................. 64 57 64 58 / 80 80 100 80
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ508-509-520-524>526-538>540.
&&
$$
41
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
611 AM EDT WED SEP 17 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE EARLY THIS MORNING. HIGH PRESSURE
WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM WEDNESDAY...PRECIPITATION ASSOCIATED WITH A COLD
FRONT DROPPING SOUTH ACROSS THE FORECAST AREA HS MOSTLY PETERED
OUT THIS MORNING AS THE ATMOSPHERE HAS STABILIZED OUT. HAVE
LOWERED POPS TO SLIGHT CHANCE FOR THIS MORNING...REST OF FORECAST
REMAINS INTACT. PREVIOUS DISCUSSION FOLLOWS:
PRECIPITATION ASSOCIATED WITH A COLD FRONT DROPPING SOUTH ACROSS
THE FORECAST AREA IS MOVING EAST AND TRANSITIONING TO A MORE
STRATIFORM EVENT AS THE ATMOSPHERE CONTINUES TO STABILIZE.
HOWEVER..THERE IS STILL SOME SHOWER/THUNDERSTORM ACTIVITY AS AN
UPPER DISTURBANCE IMPINGES UPON THE AREA. THIS DISTURBANCE IS
INDUCING CYCLOGENESIS ALONG THE FRONT...LIKELY OVER OUR FAR
WESTERN COUNTIES...WHERE THE STRONGEST CONVECTION IS OCCURRING.
A CONSENSUS OF GUIDANCE JUMPS FRONT OFFSHORE AND SOUTH OF THE
EASTERN CAROLINAS BY DAYBREAK AS CYCLOGENESIS STRENGTHENS OFF THE
COAST. FOR THE REMAINDER OF THE DAY AND OVERNIGHT...THE COMBINATION
OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND LOW PRESSURE
OFFSHORE WILL BRING A SEASONALLY COOL EAST TO NORTHEASTERLY FLOW TO
THE AREA. HIGHS WILL RANGE FROM THE LOWER 80S UP NORTH TO THE MID
80S FURTHER SOUTH. WILL RETAIN THE LOW CHANCE OF CONVECTION TODAY
AND THIS EVENING AS MODEL SOUNDINGS INDICATE A MARGINALLY TO
MODERATELY UNSTABLE AIRMASS IN CONJUNCTION WITH A SERIES OF WEAK
UPPER IMPULSES DROPPING INTO THE BASE OF THE H/5 LONGWAVE TROUGH
LINGERING OVER EASTERN CONUS. A ADDITIONAL FACTOR FAVORING
PRECIPITATION TODAY WILL BE THE LOW LEVEL CONVERGENCE RESULTING FROM
WESTERLY WINDS ALOFT RIDING OVER EASTERLY WINDS BELOW.
OVERNIGHT LOWS WILL CONTINUE IN THE SEASONAL VEIN...WITH LOW RANGING
FROM THE LOWER 60S INLAND TO THE MID 60S CLOSER TO THE COAST AND
UPPER 60S AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SURFACE HIGH OVER THE GREAT LAKES THU WILL
SHIFT EAST TO NEW ENGLAND FRI...SETTING UP A CLASSIC WEDGE. LIGHT
NORTHEAST FLOW THU AND LIMITED LOW LEVEL MOISTURE MAY ALLOW FOR SOME
SUNSHINE BUT INCREASED NORTHEAST FLOW AND LOW LEVEL MOISTURE FRI
WILL LIKELY LEAD TO AN INCREASE IN CLOUD COVER. PRECIP CHANCES ARE
RATHER LIMITED EACH DAY WITH WEAK SUBSIDENCE ALOFT KEEPING THE MID
LEVELS DRY. THE ONLY REAL THREAT APPEARS TO BE ALONG THE IMMEDIATE
COAST WHERE LOW LEVEL MOISTURE IS HIGHEST...ESPECIALLY FRI...AND
SOME LIGHT RAIN COULD DEVELOP. MEASURABLE RAINFALL WILL BE DIFFICULT
TO COME BY EVEN IF LIGHT RAIN DEVELOPS SO PLAN TO CONTINUE CARRYING
SLIGHT CHC/LOW CHC ALONG THE COAST WITH POP AROUND 10 INLAND.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN AND A LITTLE LESS MARINE
INFLUENCE. LOW TEMPERATURES WILL END UP A LITTLE ABOVE CLIMO DUE TO
CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...HIGH PRESSURE WEDGE IN PLACE AT THE START OF
THE PERIOD WILL HOLD ON INTO AT LEAST THE SECOND HALF OF THE
WEEKEND...KEEPING TEMPERATURES IN MOST AREAS A LITTLE BELOW CLIMO.
GUIDANCE IS SHOWING HINTS THE WEDGE COULD HOLD ON INTO MON GIVEN THE
LACK OF SURFACE AND MID LEVEL FEATURES. THIS WOULD MAINTAIN LOW
CLOUDS AND LIGHT PRECIP...MAINLY ALONG THE COAST...INTO NEXT WEEK.
FARTHER INLAND THERE IS LIKELY TO BE A NARROW GRADIENT BETWEEN
MOSTLY CLOUDY AND MOSTLY SUNNY. THIS IS COMPLICATED SOMEWHAT BY
POTENTIAL WEAK LOW PRESSURE DEVELOPING ALONG THE FRONT STALLED
OFFSHORE. THIS FEATURE COULD ENHANCE THE WEDGE AS IT MOVES UP THE
COAST BEFORE HELPING TO BREAK THE WEDGE AS IT EXITS NORTHEAST.
HOWEVER ITS INFLUENCE ON THE AREA REMAINS IN QUESTION WITH MANY OF
THE MEDIUM RANGE SOLUTIONS KEEPING THIS FEATURE ON THE WEAK SIDE AND
FARTHER OFF THE COAST.
COLD FRONT APPROACHES FROM THE NORTHWEST MON...DRIVEN SOUTH BY
STRONG MID LEVEL TROUGH DIVING SOUTH ACROSS THE GREAT LAKES AND
CANADIAN HIGH PRESSURE. FROPA DURING THE DAY MON WILL HAVE SOME
DIURNAL INSTABILITY TO WORK WITH...BUT HOW MUCH REMAINS A QUESTION.
EXPECT CONVECTION AHEAD OF THE FRONT BUT STRENGTH AND COVERAGE WILL
PARTLY DEPEND ON TIMING. FRONT STALLS OFFSHORE MON NIGHT INTO
TUE...SIMILAR TO THIS WEEKS COLD FRONT AS SURFACE HIGH BUILDS IN
FROM THE GREAT LAKES.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE HRRR SUGGESTS SLOW-MOVING SHOWER/TSTM ACTIVITY
ALONG THE COLD FRONT MAY STILL PLAGUE OUR INLAND TAF SITES AT THE
START OF THE PERIOD. THEREFORE WILL INCLUDE VCSH FOR KFLO/KLBT
FROM 06-08Z. INCREASING DEBRIS CLOUDS FROM FRONTAL CONVECTION WILL
LIKELY LIMIT FOG POTENTIAL OVERNIGHT. HAVE JUST INCLUDED TEMPO
MVFR VSBYS... MAINLY EARLY IN THE PERIOD AS THE NORTHEASTERLY
SURGE AFTER 09Z OR SO SHOULD MIX OUT ANY LINGERING BR. COULD ALSO
SEE SOME MVFR CIGS DEVELOP BEHIND THE FRONT THIS MORNING...BUT IFR
POTENTIAL APPEARS LOW EVEN FOR THE INLAND TERMS. MVFR CIGS COULD
LINGER THROUGH THE LATE MORNING HOURS BEFORE IMPROVING TO VFR BY
MIDDAY. EXPECT NE WINDS AOB 10 KT BEHIND THE FRONT TO PERSIST
THROUGH THE PERIOD.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
A LIGHT EAST TO NORTHEASTERLY FLOW OF AROUND 10 KTS WILL DEVELOP
OVER THE WATERS TODAY AND TONIGHT AS A COLD FRONT DROPS SOUTH OF
THE AREA. WIND WAVES WILL BE IN THE MODEST 1 TO 2 FT RANGE...BUT
WILL BE SUPPLEMENTED BY SWELL FROM DISTANT HURRICANE
EDOUARD...BRINGING A COMBINED SEA HEIGHT RANGING FROM 2 TO 4 FT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...LIGHT NORTHEAST FLOW ON THU WILL INCREASE
SIGNIFICANTLY FRI AS HIGH PRESSURE BUILDS DOWN THE COAST AND
GRADIENT BECOMES PINCHED. THU NORTHEAST FLOW WILL BE IN THE REALM OF
10 KT BUT BY MIDDAY FRI SOLID 20 KT WITH HIGHER GUSTS IS EXPECTED.
SEAS 2 TO 4 FT THU FLIRTS WITH HEADLINE CRITERIA FRI...ESPECIALLY
NORTH OF CAPE FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT
ACROSS PARTS OF NC WATERS.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...ELEVATED NORTHEAST FLOW CONTINUES SAT AS
HIGH PRESSURE RIDGES DOWN THE COAST. GRADIENT WILL MAINTAIN 15 TO 20
KT WINDS SAT BUT WEAKENING GRADIENT SUN WILL ALLOW FOR A REDUCTION
IN SPEEDS. WEAK LOW PRESSURE PASSES EAST OF THE WATERS SUN. IN THE
WAKE OF THIS LOW SUN NIGHT LIGHT SOUTHWEST FLOW WILL DEVELOP. SEAS 3
TO 5 FT WITH OCCASIONAL 6 FT POSSIBLE SAT DECREASE TO 2 TO 4 FT SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...BJR
MARINE...REK/III
AREA FORECAST DISCUSSION
NWS TULSA OK
640 AM CDT WED SEP 17 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FLIGHT CONDITIONS WILL BE HIGHLY VARIABLE THE FIRST COUPLE HOURS
OF THE FORECAST PERIOD DUE TO AREAS OF LOW CLOUDS AND FOG.
CONDITIONS SHOULD IMPROVE TO VFR BY MIDDAY AT ALL SITES. SCATTERED
SHOWERS AND THUNDERSTORMS WILL AFFECT MAINLY THE NORTHWEST
ARKANSAS SITES LATE THIS AFTERNOON AND TONIGHT. AREAS OF LOW
CLOUDS AND LIGHT FOG MAY DEVELOP AGAIN LATE TONIGHT RESULTING IN
MVFR CONDITIONS AT TIMES.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT WED SEP 17 2014/
DISCUSSION...
THUNDERSTORMS HAVE BLOSSOMED OVER EASTERN KANSAS WITHIN THE PAST
HOUR OR TWO IN RESPONSE TO A DISTURBANCE IN THE CENTRAL PLAINS AND
THE APPROACH OF A STRONG UPPER JET. MOVEMENT OF THE CURRENT
ACTIVITY CONFIRMS THE LOCAL WRF AND HRRR SOLUTIONS THAT KEEP THE
BULK OF THIS NORTH OF THE OKLAHOMA AND ARKANSAS BORDERS UNTIL THIS
AFTERNOON. WILL CONTINUE WITH SMALL POPS IN FAR NORTHEAST OKLAHOMA
AND FAR NORTHWEST ARKANSAS THROUGH THE MORNING HOURS...WITH HIGHER
CHANCES THIS AFTERNOON AND INTO TONIGHT. ONGOING PATCHY BUT
OCCASIONALLY DENSE FOG IN NORTHWEST ARKANSAS SHOULD BE GONE
SHORTLY AFTER SUNRISE. PER SURFACE OBS...VISIBILITIES HAVE VARIED
WILDLY THIS MORNING AT ANY ONE LOCATION WHICH COULD MAKE FOR A
DIFFICULT COMMUTE ESPECIALLY IN THE BENTON AND WASHINGTON
COUNTIES. AFTERNOON TEMPERATURES TODAY LOOK TO BE ABOVE NORMAL IN
MOST AREAS...WITH SOME SPOTS ALONG AND WEST OF HIGHWAY 75 LIKELY
TO TOUCH 90 DEGREES.
ANOTHER ROUND OF THUNDERSTORMS SHOULD DEVELOP AND AFFECT A BIGGER
SECTION OF EASTERN OKLAHOMA AND WESTERN ARKANSAS LATE TONIGHT AND
PERHAPS INTO TOMORROW AS ANOTHER SEGMENT OF THE UPPER JET
STRENGTHENS TO OUR EAST AND A DISTURBANCE MOVES THROUGH MISSOURI
AND ARKANSAS. A BRIEF DRYING TREND STILL APPEARS TO BE IN THE
OFFING FOR FRIDAY AND INTO FRIDAY NIGHT...AS UPPER RIDGING QUICKLY
BUILDS INTO THE PLAINS.
THE PATTERN WILL REMAIN FAIRLY PROGRESSIVE...HOWEVER...AS A STRONG
COLD FRONT IS STILL ON TRACK FOR THE WEEKEND. WITH THE REMNANTS OF
ODILE MOVING INTO THE REGION...A HEAVY RAIN EVENT CONTINUES TO
LOOK LIKELY SOMEWHERE IN THE SOUTHERN OR CENTRAL PLAINS. WITH THE
EXCEPTION OF YESTERDAYS 12Z RUN OF THE ECMWF...MOST MEDIUM RANGE
MODEL SOLUTIONS STILL PLACE THE HEAVY RAIN AXIS TO OUR
NORTH...WHILE STILL ALLOWING FOR SOME BENEFICIAL RAIN AMOUNTS
ACROSS PARTS OF NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS.
TIMING OF THE HEAVIEST RAIN CURRENTLY LOOKS TO BE BETWEEN 18Z
SATURDAY AND 06Z SUNDAY. THE RAIN SHOULD CLEAR QUICKLY ENOUGH TO
ALLOW FOR A DRY BUT COOL BEGINNING TO NEXT WEEK.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
149 PM CDT WED SEP 17 2014
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
AREA OF SHRA/TSRA ONGOING ACROSS SRN MO IS BEGINNING TO ACCELERATE
AS THE STRONGEST CELLS ALONG THE WRN HALF OF THIS COMPLEX DROPS SOUTH
INTO AR. SEVERAL OF THE RECENT RUNS OF THE HIGH-RES HRRR HAVE DONE A
REASONABLE JOB ON THESE FEATURES...AND SHOW THIS ACTIVITY DROPPING
GENERALLY SOUTH THROUGHOUT THE AFTERNOON HRS. EXPECTING THIS
ACTIVITY TO GENERALLY FOLLOW THE HIGHER INSTABILITY AXIS ACROSS
THE WRN HALF TO TWO-THIRDS OF THE STATE WHERE MOST UNSTABLE CAPE
VALUES ARE ON THE ORDER OF 1-3K J/KG AT THIS HR. AS A RESULT...DO
HAVE HIGHEST POPS THROUGH MID AFTERNOON OVER THE NRN AND NWRN
SECTIONS OF THE CWA...THEN DROPPING SOUTH TO SW OVER TIME LATER
THIS AFTERNOON. THE HRRR SOLUTIONS EVEN KEEP THIS ACTIVITY GOING
INTO THE SWRN SECTIONS OF THE AREA BY THIS EVENING...SO HAVE
GENERALLY FOLLOWED THIS TREND WITH POPS. HOWEVER...DO DROP POPS
OVER TIME AS UNCERTAINTY IN COVERAGE AN INTENSITY INCREASES BY
LATE THIS EVENING REGARDING THIS ONGOING CONVECTIVE ACTIVITY.
BEYOND THIS EVENING...THE TIMING AND PLACEMENT OF WHAT MAY BE THE
NEXT UPPER DISTURBANCE MOVING OVER THE STATE BECOMES A BIT
UNCERTAIN. EARLIER SHORT TERM MODEL SOLUTIONS HAVE THE NEXT WAVE
MOVING OVER LATE TONIGHT INTO THU MORNING...BUT THIS MAY NOT BE THE
CASE WITH THE ONGOING ACTIVITY AND ITS EXPECTED PATH. THE NEXT WAVE
MAY BE DELAYED A BIT LONGER...BUT MAY ALSO NOT BE AS INTENSE AS
EARLIER EXPECTED. WITH THAT SAID...CONTINUE WITH GENERALLY LOCATION
OF CHANCE POPS FOR MUCH OF THU...BUT HAVE DECREASED POPS SOME AS A
RESULT OF THE UNCERTAINTY OF WHEN/WHERE THE NEXT WAVE MAY MOVE.
BY FRI INTO EARLY SAT...AN UPPER RIDGE WILL MOVE OVER THE
REGION...DECREASING POPS AND INCREASING TEMPS ACROSS THE STATE. BY
LATE IN THE PERIOD THOUGH...HAVE INCREASING POPS WITH THE APPROACH
OF AN UPPER LOW OR THE REMNANTS OF ODILE AS THEY APPROACH FROM THE
WEST/NW.
&&
.LONG TERM...SUNDAY THROUGH WEDNESDAY
A COLD FRONT WILL BE MAKING ITS WAY THROUGH THE STATE AT THE START
OF THE LONG TERM...WITH SOME RAIN CHANCES MAKING THEIR WAY INTO THE
AREA THROUGH MONDAY AFTERNOON. THOUGH...LATEST MODEL SOLUTIONS SEEM
LESS AMBITIOUS ABOUT WIDESPREAD RAINFALL IN THE STATE.
AS RAIN CHANCES DISSIPATE BY MONDAY...COOLER AIR WILL FILTER INTO THE
STATE. BOTH HIGH AND LOW TEMPERATURES WILL BE FAIRLY NORMAL TO
SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF SEPTEMBER IN ARKANSAS.
WINDS WILL GENERALLY BE OUT OF THE NORTH THROUGH THE EXTENDED PERIOD
AND A COOL NORTHWEST FLOW ALOFT WILL BE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 64 80 62 83 / 30 30 10 10
CAMDEN AR 71 88 68 89 / 40 40 20 10
HARRISON AR 63 78 61 80 / 40 30 10 10
HOT SPRINGS AR 69 86 67 85 / 50 30 20 10
LITTLE ROCK AR 69 85 66 86 / 50 30 20 10
MONTICELLO AR 71 88 67 88 / 30 30 20 10
MOUNT IDA AR 67 85 65 84 / 40 30 20 10
MOUNTAIN HOME AR 63 78 60 81 / 30 30 10 10
NEWPORT AR 64 80 61 83 / 30 30 10 10
PINE BLUFF AR 70 87 66 87 / 40 30 20 10
RUSSELLVILLE AR 67 85 65 84 / 40 30 10 10
SEARCY AR 66 82 63 83 / 40 30 10 10
STUTTGART AR 68 84 65 85 / 40 30 20 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...62 / LONG TERM...226
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
221 PM MDT WED SEP 17 2014
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 220 PM MDT WED SEP 17 2014
CONVERGENCE BOUNDARY CONTINUES TO SPARK SCATTERED SHOWERS AND
THUNDERSTORMS OVER ELBERT AND LINCOLN COUNTIES THIS AFTERNOON.
ADDITIONAL OUTFLOW BOUNDARIES FROM THE SHOWERS WILL HELP TO AID
IN ADDITIONAL DEVELOPMENT FOR THE REST OF THE AFTERNOON AND EARLY
EVENING. THE OTHER AREA FOR POTENTIAL STORMS IS OVER THE
CYS RIDGE AND FAR NORTHEAST PLAINS. STRONGER STORMS IN WYOMING
EXPECTED TO MOVE INTO THE FAR NE PLAINS LATER THIS AFTERNOON AND
TAP INTO A BIT HIGHER LOW LEVEL MOISTURE. THIS MAY LEAD TO A
STRONGER/POTENTIAL ISOLATED SEVERE STORM WITH SURFACE BASED CAPES
OF 800-1500J/KG. LATEST HRRR STILL SUGGESTS ISOLATED THUNDERSTORMS
OVER THE NE PLAINS AND WILL EXPAND COVERAGE A BIT FOR EVENING
FORECAST BASED ON LATEST TRENDS.
A RIDGE OF HIGH PRESSURE WILL CENTER ITSELF OVER CO ON THURSDAY.
INCREASING MID LEVEL SUBSIDENCE ASSOCIATED WITH THE RIDGE MAY NIX
AFTN TSTM COMPLETELY FM THE FORECAST. SOME LOW LOW MOISTURE IS
PROGGED TO ADVECT INTO THE NORTHEAST CORNER OF THE STATE LATE
TONIGHT AND EARLY THURSDAY MORNING SO WL KEEP THE MENTION OF
PATCHY FOG THERE AS WELL. HIGH TEMPERATURES SIMILAR TO
TODAY...MAYBE EVEN A DEGREE OR TWO WARMER WITH LESS SUBTROPICAL
MOISTURE AROUND.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1013 AM MDT WED SEP 17 2014
THE UPPER LEVEL RIDGE WILL BREAK DOWN AND MOVE EASTWARD THROUGH
FRIDAY. FLOW WILL BE FROM THE SSW WITH THE LOW OVER THE SW COMING
IN UNDER THE RIDGE. THIS SYSTEM WILL REMAIN TO THE SOUTH WITH MOST
OF THE MOISTURE COMING BEHIND THE SURFACE FRONT THAT WILL MOVE
THROUGH FRIDAY. THE FRONT WILL BRING IN STRONG SOUTHERLY FLOW TO
THE EASTERN PORTIONS OF THE REGION WITH INCREASED MOISTURE BEHIND
IT. THERE IS ALSO SOME WEAK QG LIFT BEHIND THE FRONT THAT WILL
ALLOW FOR SOME SHOWER/TS DEVELOPMENT OVER THE MOUNTAINS AND
FOOTHILLS FRIDAY AFTERNOON AND EVENING.
FOR SATURDAY SUBSIDENCE AND DOWNSLOPE WINDS BEHIND THE FRONT WITH
UPPER LEVEL RIDGING RETURNING WILL HELP TO DRY THINGS OUT AND KEEP
TEMPS AT OR JUST ABOVE SEASONAL NORMALS. ON SUNDAY FLOW AROUND THE
UPPER RIDGE WILL COMBINE WITH MOISTURE OUT AHEAD OF THE NEXT
SYSTEM MOVING INTO THE GREAT BASIN BY SUNDAY AFTERNOON TO KEEP THE
WEATHER UNSETTLED THROUGH THE PERIOD. FOR SUNDAY THERE IS A SLIGHT
CHANCE OF TS DURING THE AFTERNOON WITH TEMPS IN THE MID 70S
BECOMING COOLER ON MONDAY.
THE UPPER TROUGH/CLOSED LOW WILL TRACK IN BY MONDAY AFTERNOON
WITH PWS RANGING FROM 0.90-1.00 AND DEWPOINTS IN THE MID 50S BY
12Z MONDAY. THIS COMBINED WITH DECENT QG LIFT WILL BRING A GOOD CHANCE
OF WIDESPREAD SHOWERS/TS ON MONDAY THROUGH TUESDAY AS THE LOW
CONTINUES TO TRACK TOWARD THE NE. TEMPS WILL BE AT OR BELOW
SEASONAL NORMALS IN THE LOWER 70S AT THE START OF THE WEEK SLOWLY
INCREASING BY WEDNESDAY BACK TO THE UPPER 70S AND LOWER 80S.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1013 AM MDT WED SEP 17 2014
NO CIG/VSBY RESTRICTIONS OVER THE NEXT 24 HOURS. TYPICAL
DIURNAL WINDS EXPECTED AS WELL. ANY TSTM DEVELOPMENT THIS EVENING
WILL BE WELL TO THE EAST AND SOUTH OF DENVER.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN/COOPER
LONG TERM...BOWEN
AVIATION...COOPER
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
137 PM EDT WED SEP 17 2014
.UPDATE...
THE WINDS WILL REMAIN WESTERLY THIS AFTERNOON AT 5 TO 10 KNOTS
BEFORE DECREASING TO 5 KNOTS OR LESS TONIGHT AT ALL OF THE TAF
SITES. ISOLATED SHOWERS AND THUNDERSTORMS ARE DEVELOPING OVER THE
INTERIOR AREAS OF SOUTH FLORIDA EARLY THIS AFTERNOON. THIS
ACTIVITY WILL CONTINUE TO DEVELOP AND PUSH EAST INTO THE EAST
COAST METRO AREAS AFTER 19Z TODAY. SO WILL CONTINUE THE VCTS IN
THE EAST COAST TAF SITES WITH EVEN A TEMPO GROUP BETWEEN 19Z AND
21Z FOR REDUCE VIS AND CEILING...AS THE HRRR SHORT RANGE MODLES
ARE SHOWING SHOWERS AND THUNDERSTORMS AFFECTING THE EAST COAST TAF
SITES DURING THIS TIME FRAME.
THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD DISSIPATE AFTER 00Z
TONIGHT OVER THE EAST COAST TAF SITES. SO HAVE KEPT THE EAST COAST
TAF SITES DRY FOR TONIGHT.
KAPF TAF SITE SHOULD ALSO SEE SHOWER AND THUNDERSTORM ACTIVITY FOR
EARLY THIS AFTERNOON...AS A LINE OF SHOWERS AND THUNDERSTORMS ARE
MOVING SOUTHWEST TOWARD THIS TAF SITE. THEREFORE...A TEMPO GROUP
HAS ALSO BEEN ADDED FOR KAPF TAF SITE FROM 18Z UNTIL 20Z. THE
WEATHER AT KAPF TAF SITE SHOULD ALSO BECOME DRY TONIGHT AS THE
SHOWER AND THUNDERSTORM ACTIVITY DISSIPATES.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 951 AM EDT WED SEP 17 2014/
UPDATE...
MINOR CHANGES WERE MADE TO THE PREVIOUS FORECAST. THE LATEST
SHORT RANGE MODEL GUIDANCE LOOKS ON TRACK WITH SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE INTERIOR BY THE LATE MORNING AND
EARLY AFTERNOON HOURS AS A COLD FRONT CONTINUES TO MOVE THROUGH
NORTHERN AND CENTRAL FLORIDA. WITH THE SOUTHWESTERLY FLOW IN
PLACE, THESE SHOWERS AND THUNDERSTORMS WILL THEN MOVE OVER THE
EAST COAST METRO AREAS THROUGHOUT THE AFTERNOON AND THEN DISSIPATE
AS THEY MOVE OVER THE ATLANTIC COASTAL WATERS DURING THE EVENING.
THE STRONGEST STORMS COULD PRODUCE WIND GUSTS UP TO 40 MPH AS WELL
AS FREQUENT LIGHTNING. THEREFORE POPS HAVE BEEN RAISED A LITTLE
BIT OVER THE EAST COAST AND LOWERED A LITTLE BIT OVER THE WEST
COAST FOR TODAY.
&&
PREV DISCUSSION... /ISSUED 745 AM EDT WED SEP 17 2014/
UPDATE...
THE WIND FLOW TODAY WILL BE FROM THE WESTERLY DIRECTION AT ALL OF
THE TAF SITES WITH WIND SPEEDS OF 5 TO 10 KNOTS. SHOWERS AND
THUNDERSTORMS SHOULD START TO DEVELOP OVER THE WEST COAST LATE
THIS MORNING AND PUSH EAST ACROSS THE AREA THROUGH THE EARLY
AFTERNOON HOURS. THE SHOWERS AND THUNDERSTORMS SHOULD THEN BE
MOVING INTO THE EAST COAST TAF SITES BETWEEN 19Z AND 01Z TODAY.
SO VCSH WILL CONTINUE OVER THE EAST COAST TAF SITES FROM 15Z UNTIL
19Z BEFORE VCTS BETWEEN 19Z AND 01Z. FOR KAPF TAF SITE...VCTS FROM
16Z UNTIL 21Z THEN VCSH FOR REST OF THE EVENING HOURS.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS AT THIS TIME
FOR THE TAF SITES ACROSS SOUTH FLORIDA. HOWEVER...ANY SHOWERS AND
THUNDERSTORMS THAT DO MOVE THROUGH THE AREA COULD REDUCE THE
CEILING AND VIS DOWN TO MVFR CONDITIONS WHICH SHOULD ONLY LAST
ABOUT 30 MINUTES. IF IT LOOKS LIKE THE REDUCED VIS OR CEILING WILL
LAST LONGER WITH THE SHOWERS AND THUNDERSTORMS THEN A SHORT TEMPO
GROUP WILL BE NEEDED.
&&
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 411 AM EDT WED SEP 17 2014/
SHORT TERM...
HIGH PRESSURE OVER THE GULF IS WEAKENING AS A TROUGH OVER THE
EASTERN UNITED STATES DIGS SOUTH. THIS WILL KEEP MAINLY AFTERNOON
SHOWERS AND THUNDERSTORMS IN THE FORECAST TODAY. A BROAD LOW OVER
THE ATLANTIC, JUST OFF THE GEORGIA COAST, WILL SLOWLY DEEPEN AND
DRIFT EASTWARD THROUGH THE DAY TODAY. THE DEVELOPING LOW AND
UPPER LEVEL TROUGH HAVE CHANGED THE FLOW FROM NORTHERLY YESTERDAY
TO MORE WEST TO SOUTHWESTERLY TODAY. THIS WILL CAUSE MOST OF THE
CONVECTION TO BE IN THE INTERIOR AND EAST COAST, AS OPPOSED TO
THE GULF SIDE YESTERDAY. MODELS ARE SHOWING IT MAY BE A LITTLE
DRIER TODAY, WITH PWATS AROUND 1.8 INCHES, RATHER THAN JUST OVER 2
INCHES YESTERDAY. 500 MB TEMPS, ON THE NAM FORECAST SOUNDING,
LOOKS TO BE A LITTLE WARMER THAN YESTERDAY, WITH IT SITTING AROUND
-6.0C. NORMALIZED CAPE LOOKS TO BE AROUND .1, COMPARED TO THE .18
YESTERDAY. THAT WOULD INDICATE WEAK VERTICAL ACCELERATIONS. SO,
EXPECT SHOWERS TO DEVELOP THIS AFTERNOON. THUNDERSTORMS WILL ALSO
BE POSSIBLE, GIVEN THE UPPER LEVEL TROUGH IN THE AREA. MOST, IF
NOT ALL THE STORMS SHOULD BE GARDEN VARIETY THUNDERSTORMS TODAY.
BY TOMORROW, PWATS DO GO BACK TO JUST OVER 2 INCHES AND THERE IS
AN INVERTED TROUGH OVER SOUTH FLORIDA, ACCORDING TO THE GFS. THE
ECMWF DOESNT SHOW THE INVERTED TROUGH, BUT IT DOES HAVE WEAK LOW
PRESSURE OVER THE AREA. WINDS TOMORROW WILL BEGIN SOUTHWESTERLY,
BUT SHOULD TURN MORE SOUTHERLY IN THE LATE AFTERNOON. THIS WOULD
MAKE THE EASTERN LAKE REGION THE MOST LIKELY TO SEE ACTIVE
WEATHER TOMORROW. MODELS ALSO SHOW A WEAK COLD FRONT TRYING TO
PUSH SOUTH INTO THE AREA. HOWEVER, IT IS STILL PRETTY EARLY IN
THE SEASON FOR A FRONT AND WOULD NOT BE SURPRISED TO SEE IT STALL
OVER CENTRAL FLORIDA INSTEAD. BUT THIS WILL BRING SOME ADDITIONAL
INSTABILITY TO THE AREA, ESPECIALLY IN THE LAKE REGION.
AS WE MOVE FORWARD TO FRIDAY, MODELS ARE STILL INDICATING THE COLD
FRONT WILL PUSH SOUTH OF THE LAKE IN THE EARLY FRIDAY MORNING
HOURS. BUT AGAIN, IT MAY NOT MAKE IT THIS FAR SOUTH. BUT, AHEAD
OF IT THERE SHOULD BE GENERAL INSTABILITY AND WEAK SURFACE FLOW.
THIS SHOULD ALLOW FOR THE SEA BREEZE AND LAKE BREEZE TO DEVELOP.
THIS WILL CAUSE SOME AREAS OF CONVERGENCE FRIDAY, THAT WILL
TRIGGER CONVECTION BY THE AFTERNOON HOURS. PWATS REMAIN AROUND 2
INCHES AND THE UPPER LEVEL TROUGH DOES LOOK TO DIG FURTHER SOUTH.
SO, HAVE SOMEWHAT HIGHER POPS IN THE FORECAST FOR FRIDAY.WITH
LIGHT FLOW, AND PLENTY OF MOISTURE, THE SHOWERS AND STORMS COULD
BRING HEAVY RAIN AND POSSIBLY SOME MINOR URBAN FLOODING FRIDAY
AFTERNOON TO THE SOUTH FLORIDA ATLANTIC COAST METRO AREAS.
LONG TERM...
FOR SATURDAY THROUGH TUESDAY NIGHT...
THE MODELS BRING A STRONGER UPPER LEVEL LOW TO THE AREA BY
SATURDAY MORNING. THIS MAY BRING INCREASING CHANCES FOR SHOWERS
AND STORMS. HOWEVER, BOTH THE GFS AND THE ECMWF ARE INDICATING
BETTER CHANCES JUST TO THE NORTH IN CENTRAL FLORIDA. GIVEN THIS,
HAVE KEPT POPS AT 50 PERCENT FOR NOW. BY SUNDAY MORNING, THE LOW
WEAKEN CONSIDERABLE AND AN UPPER LEVEL FRONT IS PROGGED TO MOVE
ACROSS SOUTH FLORIDA. THE MODELS ARE IN SOME DISAGREEMENT HOW FAST
IT WILL MOVE THROUGH , WITH THE GFS BEING MORE AGGRESSIVE. THE
ECMWF ACTUALLY LOOKS TO STALL IT OVER THE SOUTHERN PORTION OF THE
CWA ON SUNDAY. EITHER WAY, IT WILL SERVE TO BRING A SOMEWHAT
BETTER CHANCE FOR PRECIP ON SUNDAY. SO HAVE KEPT LIKELY POPS IN
THE FORECAST THAT DAY.
BY THE BEGINNING OF THE WEEK, THE BOUNDARY WILL EITHER BE OUT OF
THE AREA, OR WASHING OUT. HOWEVER, THERE WILL STILL BE A TROUGH
OVER THE EASTERN US, WITH THE BASE IN THE AREA. THIS WILL KEEP
CHANCES OF SHOWERS AND STORMS ELEVATED INTO NEXT WEEK, WITH LIKELY
POPS EACH AFTERNOON THROUGH TUESDAY. THE TROUGH WILL BEGIN TO WEAK
LATE TUESDAY, ALLOWING POPS TO DROP OFF THROUGH THE NIGHT AND INTO
WEDNESDAY MORNING.
AVIATION...
WEAK HIGH PRESSURE ACROSS THE SOUTHEASTERN GULF OF MEXICO WILL
TURN FLOW MORE SOUTHWESTERLY ACROSS SOUTH FLORIDA THROUGH THE DAY.
THIS SHOULD KEEP THE MAJORITY OF THE AFTERNOON CONVECTION ACROSS
THE INTERIOR AND EAST COASTAL AREAS. KEPT SOUTHWEST TO SOUTH-
SOUTHWEST FLOW ACROSS ALL EAST COAST SITES THROUGH THE
AFTERNOON. HOWEVER...ANY EAST COAST SEA BREEZE THAT DEVELOPS
SHOULD NOT PUSH TOO FAR INLAND BUT COULD BRIEFLY AFFECT ANY OF THE
EAST COAST SITES.
MARINE...
HIGH PRESSURE OVER THE GULF IS WEAKENING TODAY AS A WEAK COLD
FRONT SLOWLY PROGRESSES TOWARDS THE REGION. THIS WILL ALLOW FOR
CONTINUED CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH AT LEAST
THE WEEKEND, AS THE FRONT SHOULD STALL BETWEEN CENTRAL FLORIDA AND
LAKE OKEECHOBEE. ALSO, A LONG PERIOD SWELL WILL CONTINUE IN THE
ATLANTIC WATERS FOR AT LEAST THE NEXT COUPLE OF DAYS. THE HIGHEST
SWELL, OF AROUND 3 FEET, WILL BE OFF THE PALM BEACH COUNTY COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 87 74 85 / 50 60 30 60
FORT LAUDERDALE 76 88 77 86 / 50 60 40 70
MIAMI 76 88 76 86 / 50 60 30 60
NAPLES 76 87 75 86 / 40 50 30 70
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH LATE TONIGHT FOR FLZ168.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....55/CWC
AREA FORECAST DISCUSSION
NWS TOPEKA KS
346 PM CDT Wed Sep 17 2014
.SHORT TERM...(This Evening through Thursday)
Issued at 346 PM CDT WED SEP 17 2014
20 water vapor imagery shows mid level ridging over the Rockies with
the remnants of Odile moving across northern Mexico underneath the
ridge. Northwest flow persists across the central plains and a
shortwave was noted over the MT/ND boarder with another disturbance
coming across southeast WY. At the surface, a frontal boundary
remains just to the south and west of the forecast area with
easterly low level flow helping low clouds to hold strong. Where the
clouds have persisted, temps remain in the mid 70s.
For tonight model progs show some fairly dry air in the 900MB to
700MB layer over eastern KS through the night and that the better
isentropic assent combined with saturation is likely to be across
central KS where the surface boundary is located. However the
persistence of the stratus brings into question whether the models
are handling the low level moisture profile very well. Additionally
the models want to shear out the vort max that is currently
producing some lightning strikes in southeastern WY. The forecast
anticipates the better chances for elevated precip to be mainly
along the southwestern boarder where stronger low level
baroclinicity exists and where some mid level saturation is
indicated on the isentropic surfaces. However there is some doubt
especially if the disturbance coming from WY remains better defined
overnight. Mid level lapse rates are forecast to be steep enough
that some of the storms may produce some small hail over night if
they area able to develop.
Late tonight the models want to develop some dense fog overnight
with temp dewpoint spreads approaching zero. It does not look like a
classic radiational fog set up with an easterly wind persisting
through the night. In fact models show 925MB winds of 15KT or better
through the night helping to keep some mixing of the boundary layer.
If in fact there is dry air just above the surface, it is hard to
imagine a lot of fog forming. Add on the chance for some mid level
clouds and I don`t have the confidence to go with anything but
patchy fog across the northern counties where is has clear out
already. Lows tonight should fall into the lower and middle 60s for
most locations.
Thinking that fog and stratus will not be a major issue overnight,
have a forecast for Thursday with decreasing POPs and skies becoming
partly cloudy. Of course if widespread fog develops, the temp
forecast and decreasing clouds may be a little optimistic. For now
with some insolation anticipated and mixing to around 900MB, highs
are expected to be in the mid 70s to lower 80s. This is slightly
cooler from todays original forecast as models show some weak cold
air advection and cooler temps at 925MB for Thursday.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 346 PM CDT WED SEP 17 2014
First few periods of this portion of the forecast still looking dry
for the most part. Still have minor potential for more elevated
convection Thursday night, mainly in northeastern locations, as
isentropic lift picks up on increasing low level jet. Moisture
availability looks meager by this point so have kept a mention out,
but could see an isolated storm or two in the late evening and early
morning hours. Deeper mixing and good insolation expected for the
bulk of Friday for highs approaching 90.
Cold front continues on its slightly slower track with its upper
trough even weaker keeping forcing with the front meager.
Operational models and most GFS ensemble members keep the remnants
of Odile in southern Kansas with again some concern for weaker
forcing/subsidence just to its north. Given these concerns have
lowered PoPs and raised highs a bit area-wide. With upper flow
weakening could see lingering precip in southern areas into Sunday
as well. Models in fairly good agreement in cut-off upper trough
over the southwest states making east to northeast progress into the
Plains toward the mid-week. Have much uncertainty in timing and lift
potential with this and have kept chances small. As Canadian high
pressure builds southeast into the Mississippi Valley, temps are
expected to be somewhat below normal for Monday into Wednesday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1226 PM CDT WED SEP 17 2014
The terminals are expected to remain within a northeast to
easterly low level flow through the period with little or no dry
air advection at the surface. Confidence in when the stratus will
burn off is marginal, but there are signs from satellite and
recent obs that it is starting to erode. Initially based the timing
of improvements to CIGS on the RAP forecast soundings but adjusted
them to hold onto the CIGS slightly longer since there seems to be
a expansive deck of clouds still to the east and northeast.
Models have backed off on elevated precip overnight. Think this
may be due to some dry air in the 900MB to 700MB layer seen in the
isentropic surfaces. With models shearing out the upstream
vorticity or keeping the vort max to the northeast of the
terminals, think it is more likely to remain dry overnight at the
terminals and will not insert a mention of precip at this time.
MOS guidance also wants to redevelop fog (possibly dense) for
Thursday morning. However forecast soundings from the RAP and NAM
suggest any moisture will be very shallow and that 925MB winds of
15 to 20KT should keep some dry air mixing into the boundary layer
through the night. Additionally models show some possible mid
level clouds moving overhead limiting the radiational effects for
ground fog. Because of this, I`m not ready to put IFR VSBY in the
forecast.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
200 PM MDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 143 PM MDT WED SEP 17 2014
WEAK CONVECTION CURRENTLY DEVELOPING IN EASTERN COLORADO ALONG
PALMER DIVIDE AND WEAK WIND CONVERGENT ZONE WILL MOVE INTO
WESTERN KANSAS THIS AFTERNOON. INITIALLY HIGHER BASED CONVECTION
IN KIT CARSON COUNTY WHERE DEWPOINTS ARE IN THE UPPER 30S SHOULD
EVENTUALLY REACH BETTER MOISTURE AS IT WORKS EAST WHERE DEWPOINTS
ARE IN THE LOW-MID 50S. HRRR RUNS ALL MORNING HAVE CONTINUED TO
INDICATE THE POTENTIAL FOR SCATTERED SHRA/TSRA MAINLY SOUTH OF
I-70 IN KANSAS UNTIL EARLY EVENING. NAM HINTS AT THIS AS WELL.
BOTTOM LINE...HAVE INCLUDED LOW POPS TO ACCOUNT FOR THIS BUT FORCING
APPEARS WEAK AND SOME CINH REMAINS TO BE OVERCOME. OVERALL NOT
EXPECTING A BIG CONVECTIVE EVENT HERE.
WIDESPREAD STRATUS AND LOCALLY DENSE FOG IS LIKELY TO DEVELOP OVER
THE EASTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. SURFACE
DEWPOINTS WILL HOLD IN THE UPPER 50S AND LOWER 60S WITH CONTINUED
LIGHT SOUTHEAST BOUNDARY LAYER FLOW.
POTENTIAL EXISTS FOR OVERNIGHT CONVECTION...MAINLY AFTER MIDNIGHT...
EAST OF A TRENTON NEBRASKA TO HOXIE KANSAS LINE. GFS/NAM GUIDANCE
BOTH GIVE SUPPORT TO A SSE-NNW ORIENTED BAND OF SHOWERS AND
THUNDERSTORMS...ALTHOUGH TIMING AND PLACEMENT DIFFERS SOMEWHAT
BETWEEN MODELS. 500-1000 J/KG OF ELEVATED CAPE IS PRESENT TO
SUPPORT CONVECTION IF INHIBITION IS OVERCOME.
TEMPERATURES SHOULD CHANGE LITTLE NEXT COUPLE DAYS AS UPPER RIDGE
OVER THE ROCKIES SHIFTS EAST TO THE CENTRAL HIGH PLAINS. HIGHS
THURSDAY WILL AGAIN BE ABOVE NORMAL AROUND 90F GIVEN FORECAST 850
MB TEMPS 26-30C.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED SEP 17 2014
THURSDAY NIGHT-SATURDAY...FOCUS FOR THIS PORTION OF THE FORECAST IS
THE TRACK OF WHATS NOW WEAKENING TROPICAL STORM ODILE.
DEEP MOISTURE (WITH PRECIPTABLE WATER VALUES AROUND 1.5 INCHES)
ASSOCIATED WITH THE REMNANTS OF THIS SYSTEM ARE FORECAST TO REACH
AREAS SOUTH OF INTERSTATE 70 LATE FRIDAY AFTERNOON...SLIDING SLOWLY
EAST FRIDAY NIGHT AND OUT OF THE AREA EARLY SATURDAY MORNING. THE
GFS IS SLIGHTLY FURTHER SOUTH WITH THE PLUME OF MOISTURE COMPARED TO
THE 12Z NAM/00Z ECMWF...SO NO SLAM DUNK ON PRECIPITATION AMOUNTS
WITH THIS SYSTEM NOR HOW HIGH TO GO WITH POPS. IT APPEARS THAT
EITHER WAY...AS MENTIONED ABOVE...HIGHEST POPS WILL BE ALONG OR
SOUTH OF THE INTERSTATE. SOME LOCALLY HEAVY RAINFALL IS POSSIBLE IF
THE FURTHER NORTH NAM/ECMWF VERIFY.
SOUTH TO SOUTHWEST WINDS FRIDAY MID MORNING THROUGH AFTERNOON
GUSTING IN THE 25-35 MPH RANGE.
FOR SATURDAY AFTERNOON SOME MOISTURE MOVES IN FROM THE NORTHWEST
ASSOCIATED WITH AN UPPER TROUGH PASSAGE. CANT RULE OUT A FEW SHOWERS
AND MAYBE A THUNDERSTORM WITH IT WITH SLIGHT CHANCE POPS AT BEST.
SATURDAY NIGHT...DRY WITH MAYBE SOME HIGH CLOUDS MOVING IN FROM THE
WEST/SOUTHWEST.
LOWS THURSDAY NIGHT MID 50S TO MID 60S WITH SIMILAR...MAYBE A TAD
COOLER READINGS FRIDAY NIGHT.
HIGHS FRIDAY IN THE 80S WITH UPPER 70S TO LOW 80S SATURDAY.
SUNDAY-SUNDAY NIGHT...DRY WEATHER EXPECTED. MID AND HIGH CLOUDS
INCREASE FROM THE SOUTHWEST...ESPECIALLY LATE IN THE AFTERNOON
THROUGH THE NIGHT...AHEAD OF AN UPPER LEVEL LOW PRESSURE AREA MOVING
NORTHEAST TOWARD THE SLC AREA. HIGHS IN THE MID TO UPPER 70S WITH
LOWS IN THE LOW TO MID 50S. WILL BE INTRODUCING SOME SLIGHT CHANCE
TO LOW CHANCE POPS FOR SHOWERS/ISOLATED THUNDERSTORMS FOR THE
WESTERN 1/2 OF THE AREA. HIGH TEMPERATURES MID 70S TO AROUND 80 WITH
LOWS IN THE LOW TO MID 50S.
MONDAY-MONDAY NIGHT...SCATTERED TO BROKEN CLOUDINESS CONTINUES AS
THE UPPER LOW AND ASSOCIATED TROUGH LIFTS NORTHEAST TOWARD EASTERN
WYOMING. WILL NEED TO MAINTAIN SOME LOW CHANCES FOR
SHOWERS/THUNDERSTORMS. HIGHS IN THE LOW TO MID 70S WITH LOWS IN THE
LOW TO MID 50S.
TUESDAY-WEDNESDAY...UPPER LOW AND ASSOCIATED TROUGH FORECAST TO MOVE
EAST/SOUTHEAST TOWARD NORTHEAST NEBRASKA BY THE END OF THE PERIOD.
CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY SLOWLY DECREASING IN
COVERAGE FROM WEST TO EAST WEDNESDAY AS MOISTURE DECREASES FROM WEST
TO EAST WITH PASSAGE OF UPPER TROUGH. HIGHS TUESDAY IN THE LOW 70S
WITH LOW TO MID 70S WEDNESDAY. LOWS TUESDAY NIGHT IN THE LOW TO MID
50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1220 PM MDT WED SEP 17 2014
VFR THROUGH THE TAF PERIOD AT KGLD. SCATTERED CONVECTION IS
EXPECTED TO DEVELOP OVER EASTERN COLORADO EARLY THIS AFTERNOON AND
MOVE INTO WESTERN KANSAS. AT THIS TIME...THE PRECIP IS NOT
EXPECTED TO HAVE AN IMPACT ON THE TERMINAL AREA DUE TO LIMITED
COVERAGE.
MOIST LOW LEVEL FLOW WITH DEWPOINTS IN THE LOWER 60S CONTINUES
ACROSS THE KMCK AREA. IFR/LIFR CONDITIONS IN STRATUS AND DENSE FOG
EXPECTED TO DEVELOP AT KMCK AFTER AROUND 08Z AND CONTINUE THROUGH
MID-MORNING THURSDAY. SCATTERED TO BROKEN CONVECTION IS ALSO
POSSIBLE OVERNIGHT ACROSS PARTS OF NC KANSAS INTO SW NEBRASKA. SOME
UNCERTAINTY STILL EXISTS AS TO LOCATION AND IMPACT ON KMCK
TERMINAL WITH BETTER COVERAGE SEEN FURTHER EAST. CONVECTION WOULD
MOST LIKELY OCCUR IN THE 06-12Z TIME FRAME IF IT DOES DEVELOP NEAR
THE TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...99
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
143 PM MDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 143 PM MDT WED SEP 17 2014
WEAK CONVECTION CURRENTLY DEVELOPING IN EASTERN COLORADO ALONG
PALMER DIVIDE AND WEAK WIND CONVERGENT ZONE WILL MOVE INTO
WESTERN KANSAS THIS AFTERNOON. INITIALLY HIGHER BASED CONVECTION
IN KIT CARSON COUNTY WHERE DEWPOINTS ARE IN THE UPPER 30S SHOULD
EVENTUALLY REACH BETTER MOISTURE AS IT WORKS EAST WHERE DEWPOINTS
ARE IN THE LOW-MID 50S. HRRR RUNS ALL MORNING HAVE CONTINUED TO
INDICATE THE POTENTIAL FOR SCATTERED SHRA/TSRA MAINLY SOUTH OF
I-70 IN KANSAS UNTIL EARLY EVENING. NAM HINTS AT THIS AS WELL.
BOTTOM LINE...HAVE INCLUDED LOW POPS TO ACCOUNT FOR THIS BUT FORCING
APPEARS WEAK AND SOME CINH REMAINS TO BE OVERCOME. OVERALL NOT
EXPECTING A BIG CONVECTIVE EVENT HERE.
WIDESPREAD STRATUS AND LOCALLY DENSE FOG IS LIKELY TO DEVELOP OVER
THE EASTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. SURFACE
DEWPOINTS WILL HOLD IN THE UPPER 50S AND LOWER 60S WITH CONTINUED
LIGHT SOUTHEAST BOUNDARY LAYER FLOW.
POTENTIAL EXISTS FOR OVERNIGHT CONVECTION...MAINLY AFTER MIDNIGHT...
EAST OF A TRENTON NEBRASKA TO HOXIE KANSAS LINE. GFS/NAM GUIDANCE
BOTH GIVE SUPPORT TO A SSE-NNW ORIENTED BAND OF SHOWERS AND
THUNDERSTORMS...ALTHOUGH TIMING AND PLACEMENT DIFFERS SOMEWHAT
BETWEEN MODELS. 500-1000 J/KG OF ELEVATED CAPE IS PRESENT TO
SUPPORT CONVECTION IF INHIBITION IS OVERCOME.
TEMPERATURES SHOULD CHANGE LITTLE NEXT COUPLE DAYS AS UPPER RIDGE
OVER THE ROCKIES SHIFTS EAST TO THE CENTRAL HIGH PLAINS. HIGHS
THURSDAY WILL AGAIN BE ABOVE NORMAL AROUND 90F GIVEN FORECAST 850
MB TEMPS 26-30C.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 250 AM MDT WED SEP 17 2014
GOING INTO THURSDAY MORNING THERE WILL BE SOME REMNANTS SHOWERS
AND FOG ASSOCIATED WITH TROUGH PUSHING EAST OUT OF THE REGION.
UPPER RIDGE THEN SETTLES OVER THE CENTRAL PORTIONS OF THE COUNTRY
CONTINUING THE WARM TREND WITH ABOVE NORMAL TEMPS RIGHT INTO
FRIDAY NIGHT. THE REST OF THURSDAY AFTER PRECIP/CLDS CLR REGION
WILL BE DECENT SUMMER-LIKE DAY...AND TRANSLATE INTO A WARM
OVERNIGHT PERIOD AS SFC RIDGE REMAINS MAIN WX FEATURE. FOR FRIDAY
AND FRIDAY NIGHT...MODELS DO SHOW THE REMNANTS OF ODILE PASSING
JUST TO OUR SOUTH AND AN UPPER LEVEL TROUGH TO OUR NORTH. THE
COMBINATION OF THESE TWO SYSTEMS WILL BRING A CHANCE FOR RW/TRW TO
THE AREA. BEST CHANCES FOR PRECIP WILL BE IN EASTERN/SOUTHERN
ZONES CLOSEST TO ODILE REMNANTS...DUE TO ABUNDANT TROPICAL
MOISTURE IN PLACE. OVERNIGHT LOWS WILL RANGE FROM THE MID 50S INTO
THE MID 60S...WARMEST EAST.
ON SATURDAY...THE UPPER TROUGH WILL MOVE EAST TOWARD THE GREAT LAKES
WITH RISING HEIGHTS OVER THE CENTRAL HIGH PLAINS. SHORTWAVE RIDGING
BETWEEN THE AFOREMENTIONED TROUGH AND A CLOSED UPPER LOW IN THE WEST
WILL RESULT IN DRY WEATHER LATE SATURDAY THROUGH MONDAY. UNCERTAINTY
IS RATHER HIGH TOWARD THE END OF THE EXTENDED GIVEN DISCREPANCIES
WITHIN MEDIUM RANGE GUIDANCE. GFS TRANSITIONS TO AN OPEN WAVE AND
MOVES THE SYSTEM ALONG FASTER THAN THE ECMWF...ALTHOUGH THE LATEST
RUN OF THE ECMWF HAS TRENDED TOWARD THE MORE PROGRESSIVE GFS. HAVE
MAINTAINED LOW POPS ON TUESDAY BUT THE TYPICAL LOW PREDICTABILITY
WITH THESE TYPE SYSTEMS THIS FAR OUT MEANS THAT ADJUSTMENTS WILL MAY
BE NEEDED. ANOTHER DIFFERENCE IS THAT ECMWF IS MORE AGGRESSIVE WITH
A COLD FRONT/SURGE ASSOCIATED WITH ANOTHER UPPER TROUGH MOVING
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY.
HAVE TRENDED TEMPERATURES FOR BOTH MONDAY AND TUESDAY DOWN CLOSER TO
THE CONSENSUS OF THE LATEST RUNS TO ACCOUNT FOR THIS. LOW LEVEL
MOISTURE/WARMTH LOOKS TO BE INSUFFICIENT FOR MEANINGFUL INSTABILITY
TOWARD TUESDAY SO KEPT THUNDER OUT OF THE GRIDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1220 PM MDT WED SEP 17 2014
VFR THROUGH THE TAF PERIOD AT KGLD. SCATTERED CONVECTION IS
EXPECTED TO DEVELOP OVER EASTERN COLORADO EARLY THIS AFTERNOON AND
MOVE INTO WESTERN KANSAS. AT THIS TIME...THE PRECIP IS NOT
EXPECTED TO HAVE AN IMPACT ON THE TERMINAL AREA DUE TO LIMITED
COVERAGE.
MOIST LOW LEVEL FLOW WITH DEWPOINTS IN THE LOWER 60S CONTINUES
ACROSS THE KMCK AREA. IFR/LIFR CONDITIONS IN STRATUS AND DENSE FOG
EXPECTED TO DEVELOP AT KMCK AFTER AROUND 08Z AND CONTINUE THROUGH
MID-MORNING THURSDAY. SCATTERED TO BROKEN CONVECTION IS ALSO
POSSIBLE OVERNIGHT ACROSS PARTS OF NC KANSAS INTO SW NEBRASKA. SOME
UNCERTAINTY STILL EXISTS AS TO LOCATION AND IMPACT ON KMCK
TERMINAL WITH BETTER COVERAGE SEEN FURTHER EAST. CONVECTION WOULD
MOST LIKELY OCCUR IN THE 06-12Z TIME FRAME IF IT DOES DEVELOP NEAR
THE TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...JN/BRB
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1226 PM CDT Wed Sep 17 2014
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 323 AM CDT WED SEP 17 2014
The low level jet has becomes focused directly over the forecast
area and showers/storms are now developing in response to the
isentropic lift. The instability above this lift is around 1000 j/kg
with effective bulk shear near 40 kt. Given the environment can not
rule out a storm capable of producing hail likely under quarter
sized. Expect this activity to increase in coverage as it moves
eastward the next few hours. The low level jet will continue to veer
as it noses more into western MO and isentropic lift becomes better
focused there. A majority of this morning activity should stay
mainly south of interstate 70, and clear out of the area around
sunrise or shortly after. Short term models are suggesting a
potential for fog centered around sunrise especially in north
central KS. Soundings show that any fog and low level stratus will
begin to lift and scatter out from west to east. There are some
indications that the stratus could hold on longer in spots across
east central KS into the afternoon hours. By the afternoon a warm
front should be located from near Salina to Emporia or just south of
there. This is where the cap is weak and surface convergence is
present. The only limiting factor will be no mid/upper level support
to enhance the lift. With steep mid level lapse rates in place the
surface based cape will approach 3500 j/kg. Hodographs will also be
impressive with decent turning with height within the northwest flow
aloft and southerly surface flow. Deep layer shear of 35 to 40 kt
means any storm that is able to develop near the front could quickly
become strong to severe around the 21-01Z time frame. Have kept
slight chances along the southern border of the forecast area
through the evening hours. Further north of the front stratus tries
to linger as a fairly strong cap remains in place so do not expect
any development in those areas. Later in the evening the front
retreats south of the area and southerly flow increases over the
stable air mass. Elevated convection will again be possible, which
should hold off until around 03-06Z. This mornings temperatures will
remain steady with the expansive cloud cover. Highs today should
reach the mid to upper 80s in central KS, and low 80s in northeast
KS if the clouds lift as forecasted.
.LONG TERM...(Thursday through Tuesday)
Issued at 323 AM CDT WED SEP 17 2014
Thursday, scattered to isolated elevated thunderstorms will be
ongoing into the morning hours across the eastern and southern
counties of the the CWA. An upper level ridge across the high plains
will amplify through day. A stronger EML will overspread the area by
Thursday afternoon and the elevated thunderstorms across the
southeast counties should dissipate. Skies will begin to clear from
west to east across the CWA during the afternoon hours. Highs will
vary dependent on afternoon insolation. The southwest counties will
warm into the mid 80s while the eastern counties may keep cloud
cover longer through the afternoon hours and only see highs in the
upper 70s.
Thursday night through Friday night, The upper level ridge axis will
shift east across the central and southern plains into to the the
mid and lower MS river valley by Friday night. The remnants of Odile
will lift northeast around the upper ridge axis across NM into
western KS Friday night. Rain and thunderstorms will slowly spread
northeast across western KS through the night but remain west of the
CWA. Friday highs will be warm with the upper level ridge across the
southern and central plains. Highs Friday afternoon will reach the
mid to upper 80s and it will feel more humid with deeper gulf
moisture in place.
Saturday into Saturday Night, The remnants of Odile will begin to
phase with an upper level trough digging southeast across the
northern plains and upper Midwest. Rain and thunderstorm chances
will increase from west to east across the CWA during the day on
Saturday. The 6Z run of the ECMWF is slower and would bring the
heaviest rain across the CWA Saturday night. The GFS and GEM models
are more progressive in the speed of the upper trough digging
southeast across the northern plains into the upper Midwest. Both
models show the remnants of Odile remaining south of the CWA across
OK and southern KS. ATTM, I`m leaning more towards the ECMWF which
will phase the remnants of Odile with the the northern plains H5
trough during the late afternoon hours across central KS then move
both systems east-southeast across eastern KS during the evening
hours. The ECMWF forecast QPF of 1 to 3 inches rainfall Saturday
into Sunday along and south of I-70, with only a quarter inch of
QPF along the NE border. The other operational models keep the
heavier rainfall south of the CWA with half inch of QPF south of
I-70 and only about a tenth of an inch of rainfall across the
northern counties of the CWA.
Sunday Afternoon through Tuesday, If the 6Z ECMWF solution verifies
the rain and thunderstorms may continue through the morning hours
of Sunday but should end by Sunday afternoon. It looks dry into
early next week, as the H5 trough across the upper Midwest digs
southeast into the Great Lakes and amplifies. The coldest airmass
will remain east of the CWA. Highs will generally be in the mid to
upper 70s with overnight lows in the 50s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1226 PM CDT WED SEP 17 2014
The terminals are expected to remain within a northeast to
easterly low level flow through the period with little or no dry
air advection at the surface. Confidence in when the stratus will
burn off is marginal, but there are signs from satellite and
recent obs that it is starting to erode. Initally based the timing
of improvements to CIGS on the RAP forecast soundings but adjusted
them to hold onto the CIGS slightly longer since there seems to be
a expansive deck of clouds still to the east and northeast.
Models have backed off on elevated precip overnight. Think this
may be due to some dry air in the 900MB to 700MB layer seen in the
isentropic surfaces. With models shearing out the upstream
vorticity or keeping the vort max to the northeast of the
terminals, think it is more likely to remain dry overnight at the
terminals and will not insert a mention of precip at this time.
MOS guidance also wants to redevelop fog (possibly dense) for
Thursday morning. However forecast soundings from the RAP and NAM
suggest any moisture will be very shallow and that 925MB winds of
15 to 20KT should keep some dry air mixing into the boundary layer
through the night. Additionally models show some possible mid
level clouds moving overhead limiting the radiational effects for
ground fog. Because of this, I`m not ready to put IFR VSBY in the
forecast.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Gargan
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
229 PM EDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT WED SEP 17 2014
LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A SHORTWAVE MOVING
INTO WRN ONTARIO WITH ITS ASSOC UPPER JET MAX PASSING ACROSS THE TIP
OF JAMES BAY. 850 MB FGEN ALONG THE SYSTEMS COLD FRONT IS SUPPORTING
BAND OF SHRA FROM JUST NORTH OF MN BDR EXTENDING ACROSS NCNTRL AND
ERN LAKE SUPERIOR AS NOTED ON CANADIAN RADAR MOSIAC. SOME OF THESE
SHRA HAVE BRUSHED THE KEWEENAW PENINSULA EARLY THIS MORNING AND LOW
CLOUDS HAVE REACHED INTO KCMX AS WELL. OTHERWISE THE REST OF THE CWA
HAS STAYED DRY THUS FAR.
TODAY...AS THE ONTARIO SHORTWAVE DIVES ACROSS THE NRN TIP OF LAKE
SUPERIOR LATER THIS MORNING IT WILL HELP DRIVE THE COLD FRONT ACROSS
UPPER MI LATE THIS MORNING INTO THE AFTERNOON HRS. MODELS SHOW
SUPPORTING 850 MB FGEN FORCING FOR SHRA ACTIVITY GENERALLY WEAKENING
AND MOVING EAST BY LATE MORNING WITH DEPARTING SHORTWAVE AND ASSOC
UPPER JET MAX AS COLD FRONT SLOWLY BEGINS TO SHIFT SOUTH ACROSS THE
AREA. SINCE THE MODELS INDICATE THE BEST FGEN FORCING GENERALLY
STAYING OUT OVER LAKE SUPERIOR OR NORTH OF THE LAKE THROUGH LATE
MORNING HAVE KEPT HIGHER CHC/LIKELY POPS WELL NORTH OVER LAKE
SUPERIOR THIS MORNING WITH ONLY SLIGHT CHC TO LOW CHC POPS BRUSHING
THE KEWEENAW PENINSULA AND THE FAR NE CWA. THE REST OF THE CWA SHOULD
STAY GENERALLY DRY TODAY AS FGEN WILL BE WEAKENING QUICKLY ALONG THE
FRONT AS IT BEGINS TO MOVE SOUTH ACROSS UPPER MI THIS AFTERNOON.
SINCE COLD FRONTAL PASSAGE WILL BE LATER IN THE DAY FOR ALL BUT THE
NW QUARTER OF THE CWA...EXPECT TEMPS TO WARM UP INTO THE 60S OVER
SCNTRL AND ERN PORTIONS OF THE CWA WITH THE COOLEST TEMPS (AROUND
50F) ACROSS THE KEWEENAW PENINSULA. TEMPS ACROSS THE N WILL LIKELY
FALL INTO THE 40S IN THE AFTN UNDER A BRISK DEVELOPING NRLY WIND AND
STRATUS DECK FOLLOWING FROPA.
TONIGHT...CANADIAN HIGH PRESSURE BUILDING ACROSS THE AREA AND
BECOMING CENTERED NE OF LAKE SUPERIOR WILL BRING CLEARING SKIES AND
LIGHT EASTERLY WINDS. PWATS LESS THAN 30 PCT OF NORMAL OR LESS THAN
.25 INCH WILL ALLOW FOR IDEAL RADIATIONAL COOLING CONDITIONS. EXPECT
FREEZING TO BLO FREEZING TEMPS ACROSS MUCH OF THE INTERIOR OF THE
UPPER MI. HAVE POSTED FREEZE WARNINGS FOR THE INTERIOR WRN COUNTIES
AND HAVE FROST ADVISORIES OUT FOR THE REST OF THE CWA WITH THE
EXCEPTION OF KEWEENAW COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM EDT WED SEP 17 2014
NOT MUCH CHANGE IN THINKING FROM PREVIOUS SHIFT. THU WILL START WITH
LINGERING COLD AND FROST FROM WED NIGHT AS A 1025MB SFC HIGH WILL BE
CENTERED JUST NE OF THE CWA AT 12Z THU. THE HIGH WILL MOVE TO NEW
ENGLAND...WHILE STRENGTHENING TO 1030MB...BY 12Z FRI WHILE A SFC
TROUGH MOVES TO THE DAKOTAS. RETURN FLOW/WAA WILL JUST BE STARTING
LATE THU...SO DRY AIR LINGERING OVER THE REGION WILL MAKE FOR MOSTLY
SUNNY SKIES ON THU. TEMPS ON THU WILL TOP OUT IN THE MID TO UPPER
50S.
MOISTURE BEGINS TO INCREASE THU NIGHT AS THE RETURN FLOW
INCREASES...BUT MOST PRECIP LOOKS TO HOLD OFF UNTIL FRI WHEN AMPLE
MOISTURE WILL BE ESTABLISHED...A SERIES OF SHORTWAVE TROUGHS BEGINS
A TREK ACROSS THE AREA...AND THE PRESSURE GRADIENT/RETURN FLOW
INCREASES. MODELS ARE IN GOOD AGREEMENT ON THE START TIME OF PRECIP
FRI IN THE WAA REGIME...BUT HOW THINGS SHAPE UP ON FRIDAY AND
ESPECIALLY THE END TIME OF PRECIP ON SAT NIGHT OR SUN IS MORE
UNCERTAIN. EVEN THOUGH MODELS AGREE THAT THE STRONGEST SHORTWAVE
WILL ENTER THE REGION LATE SAT INTO SAT NIGHT...MODELS DISAGREE WITH
EACH OTHER AND FROM RUN TO RUN DUE TO THE COMPLEX NATURE OF PHASING
THE THREE WAVES OVER THE AREA. WILL LIKELY NOT HAVE GREATER
CERTAINTY ON END TIME OF PRECIP UNTIL CLOSER TO THE WEEKEND. HAVE
THE GREATEST POPS FROM LATE FRI THROUGH SAT. CONTINUED TO HAVE
CHANCES FOR THUNDERSTORMS LATE FRI INTO SAT NIGHT WHEN SOME ELEVATED
INSTABILITY IS EXPECTED...NO SEVERE WEATHER IS EXPECTED THOUGH.
850MB TEMPS WILL TOP OUT AROUND 15C FRI NIGHT INTO SAT...RESULTING
IN HIGH TEMPS IN THE MID 60S TO LOW 70S /WHICH IS AROUND AVERAGE/.
THE AIRMASS WILL BE COLDER SUN THROUGH TUE UNDER STRONGER NW FLOW
ALONG AND INCOMING SFC HIGH PRESSURE...RESULTING IN COOLER AND DRIER
CONDITIONS MON AND TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 227 PM EDT WED SEP 17 2014
LIGHT SHOWERS ASSOCIATED WITH THE EXITING FRONTAL BOUNDARY SINKING
ACROSS CENTRAL UPPER MI WILL CONTINUE ACROSS THE AREA WILL CONTINUE
ACROSS WI AND N LOWER MI THIS AFTERNOON. THE INCREASE IN MOISTURE
AND FAVORABLE UPSLOPE CONDITIONS HAS RESULTED IN BR OVER THE HIGHER
TERRAIN OF CENTRAL UPPER MI...AND LIFR CEILINGS AT IWD AND SAW.
CURRENT LIFR CEILINGS AT CMX AND SAW WILL SLOWLY IMPROVE THROUGH THE
LATE AFTERNOON HOURS. CURRENT TRACKING OF THE BACK SIDE OF THE
CLOUDS ACROSS CENTRAL LAKE SUPERIOR BRINGS VFR CEILINGS BACK BY
AROUND 21Z AT CMX...AND BY 23Z AT SAW AND IWD. WINDS WILL SLOWLY
TURN MORE NE TO E OVERNIGHT...AS DRIER AIR FILTER IN. EXPECT WINDS
TO REMAIN BELOW 10KTS WITH VFR CEILINGS TONIGHT THROUGH
THURSDAY...UNDER VFR CEILINGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT WED SEP 17 2014
EXPECT WINDS GENERALLY 10-20KT AS THE FRONT STALLS OVER THE LAKE
EARLY THIS MORNING. FRONT WILL GET A PUSH S LATE THIS MORNING INTO
THE AFTERNOON WITH NE WINDS BEHIND THE FRONT INCREASING TO 15-25KT FOR
AT LEAST A TIME. OVER FAR WRN LAKE SUPERIOR...COASTAL
CONVERGENCE/FUNNELING MAY RESULT IN WINDS BRIEFLY AS HIGH AS 30KT.
WINDS WILL THEN DIMINISH TO UNDER 20KT TONIGHT/THU AS HIGH PRES
SETTLES OVER NRN ONTARIO IN THE VCNTY OF LAKE SUPERIOR. AS THE HIGH
THEN SHIFTS TOWARD NEW ENGLAND AND A LOW PRES TROF APPROACHES FROM
THE W...S WINDS WILL INCREASE THU NIGHT/FRI. WITH S WINDS A MORE
FAVORABLE DIRECTION FOR STRONGER WINDS OVER ERN LAKE SUPERIOR THAN
OVER THE W...WINDS SHOULD REACH 20-30KT OVER THE ERN LAKE ON FRI.
ALTHOUGH WINDS WILL DIMINISH ON SAT AS THE TROF ARRIVES OVER THE
UPPER LAKES...W TO NW WINDS WILL AGAIN INCREASE TO AS HIGH AS
20-30KT BEHIND THE TROF SAT NIGHT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ003-005>007-012>014-085.
FREEZE WARNING FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...KF
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1250 PM CDT WED SEP 17 2014
.UPDATE...
ISSUED AT 705 AM CDT WED SEP 17 2014
SURE ENOUGH...LOCALLY DENSE FOG HAS GRADUALLY SHOWN ITS HAND
ACROSS MAINLY OUR NORTH CENTRAL KS ZONES...ALONG WITH PRIMARILY
OUR WESTERN-MOST COLUMN OF SOUTH CENTRAL NEBRASKA COUNTIES.
ALTHOUGH GROUND-TRUTH IS LIMITED...IT SEEMS THAT COUNTIES WITHIN
OUR CWA ARE MAINLY ON THE FRINGES OF MORE WIDESPREAD DENSE FOG
ISSUES MAINLY AFFECTING WESTERN NEB AND NORTHWEST KS. AS A
RESULT...HAVE OPTED AGAINST A FORMAL DENSE FOG ADVISORY AT THIS
TIME...BUT DID RECENTLY ISSUE A SPECIAL WEATHER STATEMENT TO
HEIGHTEN AWARENESS. IF CONDITIONS CONTINUE TO DETERIORATE THE
ONCOMING DAY SHIFT MAY HAVE TO CONSIDER A SHORT-FUSE ADVISORY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM CDT WED SEP 17 2014
THE MAIN FORECAST ISSUES DURING THESE NEXT 24 HOURS CONSIST
OF...FIRSTLY: WHETHER OR NOT POTENTIALLY IMPACTFUL FOG WILL YET
DEVELOP THIS MORNING AND IF SO...WILL IT REMAIN MOSTLY HIT-AND-
MISS OR BECOME MORE WIDESPREAD IN SOME AREAS. SECONDLY: WILL AT
LEAST ISOLATED THUNDERSTORMS FLARE UP THIS EVENING AND ESPECIALLY
LATE TONIGHT...AND IF SO COULD A FEW EVEN BECOME STRONG TO
MARGINALLY SEVERE. THIRDLY: ALTHOUGH STEADIER SURFACE BREEZES
SHOULD ACT AGAINST FOG FORMATION A BIT MORE SO ON WEDNESDAY NIGHT
VERSUS THIS MORNING...AT LEAST PATCHY DEVELOPMENT AGAIN APPEARS
POSSIBLE AS LOW LEVEL MOISTURE AGAIN KICKS UP ANOTHER NOTCH.
TEMP-WISE...ASSUMING NO UNEXPECTED ENHANCED CLOUD ISSUES...BY FAR
THE BIG STORY IS THAT HIGHS TODAY ARE FORECAST TO BREACH THE 80+
MARK NEARLY CWA-WIDE...IN MANY PLACES FOR THE FIRST TIME IN 9
DAYS SINCE SEP. 8TH...A PRETTY NOTABLE STRETCH CONSIDERING MOST OF
IT OCCURRED DURING THE FIRST HALF OF SEPTEMBER.
STARTING WITH THE HERE AND NOW AS OF 0830Z/330 AM...OVERALL
ANOTHER VERY QUIET NIGHT ACROSS THE CWA...AS ANY WINDOW OF
OPPORTUNITY FOR ELEVATED CONVECTION IN SOUTHEAST ZONES HAS ALL
BUT PASSED BY...AS SEVERAL MODELS CORRECTLY SUGGESTED THAT THIS
ACTIVITY WOULD INITIATE AND FOCUS AT LEAST A FEW COUNTIES OUTSIDE
THE AREA OVER EASTERN KS/WESTERN MO AND THIS IN FACT HAS BEEN THE
CASE. MEANWHILE...11-3.9 MICRON SATELLITE IMAGERY REVEALS NEARLY
CLOUD-FREE SKIES OVER THE CWA...ALTHOUGH A RECENTLY FORMED RIBBON
OF LOW STRATUS RACING NORTH OUT OF CENTRAL KS TOWARD SOUTHEAST NEB
APPEARS POISED TO POSSIBLY BARELY BRUSH OUR EXTREME SOUTHEAST
ZONES AS IT TRACKS NORTH-NORTHEAST. AT THE SURFACE...A RATHER
DISORGANIZED VERY LIGHT/VARIABLE WIND REGIME IS IN PLACE OVER THE
CWA...AS THE LOCAL AREA LIES WELL TO THE WEST OF THE PRIMARY RIDGE
AXIS OVER THE IL/IN AREA...AND JUST TO THE NORTH OF A VERY WEAK
LOW AND TROUGH AXIS OVER SOUTHWEST KS. AS SUSPECTED 24 HOURS
AGO...THE COMBO OF MAINLY CLEAR SKIES/LIGHT BREEZES HAS FOSTERED
AT LEAST SOME LIMITED FOG DEVELOPMENT...BUT BASED ON AUTOMATED
AIRPORT OBS AT LEAST SO FAR ANY FOG HAS BEEN PRETTY HIT AND MISS
IN NATURE AND LIKELY FAVORING TYPICAL LOW LYING AREAS VERSUS MORE
WIDESPREAD. THAT BEING SAID...A FEW AUTOMATED WITHIN OR VERY NEAR
THE CWA HAVE AT LEAST BRIEFLY REPORTED VISIBILITY UNDER 1
MILE...INCLUDING A LOCALIZED QUARTER MILE AT ORD. AS FOR LOW TEMPS
THIS MORNING...PARTS OF ESPECIALLY THE NORTHWEST HALF OF THE CWA
ARE HEADING TOWARD LOWS A FEW DEGREES COOLER THAN EXPECTED AS A
FEW SPOTS HAVE EVEN DIPPED INTO THE UPPER 40S...WHILE MUCH OF THE
SOUTHEAST HALF OF THE CWA SHOULD BOTTOM OUT LOW-MID 50S AND EVEN
CLOSER TO 60 FAR SOUTH. IN THE MID-UPPER LEVEL PICTURE...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM FAIRLY STEADY-
STATE NORTHWESTERLY FLOW OVER THE CENTRAL PLAINS...DIRECTED
BETWEEN A LARGE SCALE WESTERN CONUS RIDGE AND EASTERN CANADA
TROUGH. WELL TO THE SOUTHWEST...WEAKENING TROPICAL STORM ODILE IS
IN THE PROCESS OF SHIFTING OUT OF THE BAJA AREA TOWARD SOUTHERN
AZ. CLOSER TO HOME...A LOW AMPLITUDE DISTURBANCE ZIPPING SOUTHEAST
OVER THE NEB/IA/SD BORDER AREA TOWARD NORTHERN MO HAS HELPED
STRENGTHEN A WEST-SOUTHWESTERLY LOW LEVEL JET MAINLY OVER
KS...AND ITS NO COINCIDENCE THAT ITS EXIT REGION INTO THE KS/MO
BORDER REGION IS WHERE THE INCREASINGLY ACTIVE BAND OF MORNING
ELEVATED CONVECTION HAS FIRED UP.
LOOKING AHEAD AND NOW AND STARTING WITH THESE NEXT FEW HOURS
THROUGH AROUND SUNRISE...OBVIOUSLY FOG TRENDS ARE THE MAIN
CONCERN. ALTHOUGH FOG IS OFTEN A VERY FICKLE ENTITY...VERY SHORT
TERM VISIBILITY PROGS FROM THE RAP13 AND HRRR SUGGEST THAT THINGS
COULD CERTAINLY WORSEN/BECOME MORE WIDESPREAD YET THIS MORNING
PRIMARILY IN WESTERN AND SOUTHERN PORTIONS OF THE CWA...BUT MAYBE
ON A LOCALIZED BASIS ALMOST ANYWHERE. THINGS WOULD HAVE TO GET
CONSIDERABLE WORSE/WIDESPREAD TO EVEN BEGIN TO CONSIDER ANY KIND
OF FORMAL ADVISORY...BUT IT WILL LIKELY BE AT LEAST 14-15Z/9-10AM
BEFORE WE ARE COMPLETELY OUT OF THE WOODS ON SOME AREAS SEEING
VISIBILITIES NEAR/BELOW 1 MILE AND LOCALLY DENSE. THE BOTTOM LINE:
A MIX OF PATCHY FOG AND AREAS-OF FOG WORDING REMAINS IN THE
FORECAST FOR A FEW HOURS PAST SUNRISE...AND THESE TRENDS WILL BE
CLOSELY MONITORED.
GETTING BEYOND ANY MORNING FOG CONCERNS TO THE HEART OF THE
DAYTIME PERIOD...THE MAIN THEME HERE IS DRY CONDITIONS PERSISTING
IN THE PRESENCE OF NOTABLY WARMER CONDITIONS THAN OBSERVED LATELY.
IN THE MID-UPPER LEVELS...FAIRLY CONSISTENT AND LARGELY UNEVENTFUL
NORTHWESTERLY FLOW WILL CONTINUE OVER THE CENTRAL PLAINS AS THE
AFOREMENTIONED SUBTLE DISTURBANCE CURRENTLY JUST NORTHEAST OF THE
CWA DEPARTS WELL SOUTHEAST INTO THE OH VALLEY AREA BY DAYS END.
GIVEN THE LACK OF PERCEPTIBLE FORCING...CONFIDENCE IS RATHER HIGH
IN A DRY-DAY CWA-WIDE AS NEARLY ALL MODEL QPF AND REFLECTIVITY
FIELDS SUGGEST...AS ANY APPRECIABLE CONVECTIVE INSTABILITY THAT
MIGHT MANAGE TO BUILD SHOULD REMAIN CAPPED PER NAM FORECAST
SOUNDINGS. AT THE SURFACE...THE VERY LIGHT/VARIABLE BREEZES OF
THIS MORNING SHOULD GRADUALLY GIVE WAY TO PREVAILING EAST-
SOUTHEAST WINDS ONLY AROUND 10 MPH IN RESPONSE TO WEAK HIGH PLAINS
PRESSURE FALLS TO THE WEST. ONCE ANY MORNING LOWER STRATUS/FOG
THAT DEVELOPS BURNS OFF...SKIES SHOULD AVERAGE NO WORSE THAN
PARTLY CLOUDY DESPITE A FEW PASSING BATCHES OF MID-HIGH
CLOUDS...IN OTHER WORDS NO PESKY LOWER DAYTIME STRATUS DECK
ENVELOPING MUCH OF THE CWA DURING PEAK HEATING AS DID IN FACT
OCCUR YESTERDAY. THE OBVIOUS RESULT SHOULD BE A NOTICEABLE RISE
IN TEMPS VERSUS LATELY. THAT BEING SAID...DID NUDGE HIGHS DOWN
1-2 DEGREES FROM PREVIOUS FCST MAINLY ACROSS THE SOUTHERN CWA
WHILE LEAVING MUCH OF THE NORTH UNCHANGED. THE NET RESULT IS LOW
80S ACROSS MOST CENTRAL/NORTHEAST ZONES AND MAINLY MID 80S
SOUTHWEST WITH UPPER 80S MOST FAVORED IN FAR SOUTHWEST COUNTIES
SUCH AS ROOKS. THE AIRMASS WILL ALSO GET ANOTHER BOOST IN THE
HUMIDITY DEPARTMENT AS DEWPOINTS RISE INTO AT LEAST THE LOW 60S
MOST AREAS FOR THIS AFTERNOON.
TURNING TO THIS EVENING TONIGHT...THE BEST WAY TO DESCRIBE THINGS
IS THAT IT COULD BE A FAIRLY ACTIVE NIGHT IN PARTS OF THE CWA WITH
AT LEAST LIMITED STRONG THUNDERSTORM DEVELOPMENT AND AT LEAST
LIMITED FOG DEVELOPMENT...OR IT COULD ALMOST JUST AS EASILY BE
ANOTHER FAIRLY UNEVENTFUL NIGHT. SUCH IS THE FICKLE NATURE OF
NORTHWESTERLY-FLOW-ALOFT SITUATIONS WHEN LARGE-SCALE FORCING
REMAINS WEAK. SPEAKING OF THE MID-UPPER LEVELS...THE NORTHWESTERLY
FLOW PERSISTS BUT ACTUALLY MIGHT WEAKEN VERY SLIGHTLY AS THE MAIN
RIDGE AXIS ALIGNED OVER THE ROCKIES EDGES EVER SO SLIGHTLY FARTHER
EAST. THERE WILL UNDOUBTEDLY BE AT LEAST 1 OR 2 VERY LOW AMPLITUDE
DISTURBANCES WORKING SOUTHEASTWARD OVER/NEAR THE CWA TONIGHT...AND
COMPARED TO THIS MORNING THIS TIME AROUND IT APPEARS THERE WILL BE
MORE PRONOUNCED LOW-MID LEVEL CONVERGENCE OVER ESPECIALLY THE
SOUTHWESTERN 1/2 OF THE CWA TONIGHT AS NOTED IN 315K ISENTROPIC
SURFACE FORECASTS AND ALSO NOTED IN THE MORE WESTERLY FLOW AND
RESULTANT ELEVATED THETA-E ADVECTION BASED MAINLY IN THE 800-700MB
LAYER. PER VARIOUS DETERMINISTIC AND HIGHER-RES REFLECTIVITY MODEL
SOLUTIONS...AT LEAST A FEW THUNDERSTORMS ARE EXPECTED TO FLARE UP
ALONG THIS ELEVATED CONVERGENCE ZONE...WITH THE GREATEST
LIKELIHOOD WITHIN THE SOUTHWESTERN 1/2 OF THE CWA AFTER MIDNIGHT.
THAT BEING SAID...STORMS CANNOT BE COMPLETELY BE RULED OUT BEFORE
MIDNIGHT EITHER AND HAVE MAINTAINED SOME 20 POPS IN SOUTHWESTERN
AREAS DURING THE EVENING WHILE EXPANDING AT LEAST 20 POPS TO ALL
AREAS AFTER MIDNIGHT BUT FOCUSING HIGHEST 30S IN SOUTHERN ZONES.
SHOULD CONVECTION MATERIALIZE...CERTAINLY A FEW STRONG STORMS
CAPABLE OF PRODUCING HAIL TO AT LEAST NICKEL SIZE OR SLIGHTLY
LARGER CANNOT BE RULED OUT GIVEN ELEVATED CAPE OF 1000-1500 J/KG
IN THE PRESENCE OF AROUND 40KT OF DEEP LAYER SHEAR. MEANWHILE AT
THE SURFACE...FAIRLY LIGHT BUT STEADY EASTERLY BREEZES GENERALLY
5-10 MPH SHOULD PERSIST OVERNIGHT...WHICH SHOULD HELP WORK AGAINST
ANY WIDESPREAD/IMPACTFUL FOG FORMATION...ALONG WITH OF COURSE ANY
LOCALIZED MIXING FROM CONVECTIVE ACTIVITY. THAT BEING SAID...AT
LEAST PATCHY LIGHT FOG CERTAINLY CANNOT BE RULED OUT IN THE MOIST
EASTERLY FLOW...SO HAVE INTRODUCED PATCHY FOG TO THE LATE NIGHT
FORECAST. THE EARLIER 00Z NAM SUGGESTED THAT POTENTIALLY
WIDESPREAD LOW STRATUS AND POSSIBLE LIGHT DRIZZLE COULD
MATERIALIZE AS WELL...BUT THE LATEST 06Z NAM SUGGESTS THAT LOW
LEVEL MOISTURE DEPTH WILL LIKELY REMAIN INSUFFICIENT FOR DRIZZLE
PRODUCTION. MADE VERY LITTLE ALTERATION TO LOW TEMPERATURES...AS
ANOTHER UPWARD CLIMB FROM ONE NIGHT TO THE NEXT CONTINUES...WITH
LOWS AIMED FROM THE UPPER 50S NORTH...LOW 60S CENTRAL AND MID 60S
SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED SEP 17 2014
SUMMARY...FRIDAY...WITH HIGHS IN THE MID 80S...STILL APPEARS TO THE
BE THE WARMEST DAY OF THE NEXT 7 DAYS FOR MOST AREAS...ALTHOUGH IT
WILL NOT BE ALL THAT MUCH WARMER THAN TODAY. RAIN CHANCES IN THE
EXTENDED PERIOD ARE NOT THAT GOOD AND CHANCES HAVE EVEN FALLEN OFF A
LITTLE BIT DURING THE PERIODS WHERE 24HRS EARLIER THEY LOOKING THE
BEST...FRIDAY NIGHT INTO SATURDAY. OVERALL IT WILL BE A FAIRLY
TYPICAL MID SEPTEMBER PERIOD WITH HIGHS ON MOST DAYS AVERAGING OUT
IN THE 70S TO AROUND 80.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES SHOULD DECREASE. THERE IS
WEAK ISENTROPIC LIFT IN THE LOWEST LAYER FROM AROUND AND BELOW 850
MB AND FORECAST MODELS INDICATE THAT A LOW STRATUS DECK COULD
PERSIST THROUGH MUCH OF THE DAY. INITIALLY THIS STRATUS DECK MAY BE
LOW ENOUGH TO BE FOG RIGHT AFTER SUNRISE. SOME FORECAST MODELS ARE
TRYING TO GENERATE A HUNDREDTH OR TWO OF SPLOTCHY QPF. TYPICALLY
THIS COULD BE SPRINKLES...DRIZZLE...OR EVEN ISOLATED THUNDERSTORMS.
IN THIS CASE THE FORECAST SOUNDINGS INDICATE THAT THE SATURATED
STRATUS DECK WILL BE BELOW 850 MB AND NOT THICK ENOUGH TO PRODUCE
DRIZZLE. THERE COULD BE SOME CLOUD SEEDING FROM PASSING MID CLOUDS
GENERATING A FEW SPRINKLES...BUT MOST AREAS WILL BE DRY. THERE IS
SOME WEAK INSTABILITY SO WE CAN NOT RULE OUT THUNDERSTORMS...BUT
ODDS OF THUNDER ARE LOW ENOUGH TO CONTINUE TO KEEP IT OUT OF THE
FORECAST FOR NOW. THE STRATUS DECK WILL KEEP TEMPERATURES DOWN
ESPECIALLY ACROSS NEBRASKA ZONES WHERE STRATUS WILL LIKELY LINGER
LONGER. HIGHS WILL RANGE FROM THE MID 70S IN THE TRI CITIES TO THE
MID 80S ACROSS OUR SOUTHWEST KANSAS COUNTIES.
THURSDAY NIGHT INTO FRIDAY AFTERNOON...THERE IS GOOD AGREEMENT IN
NUMEROUS FORECAST MODELS AND MODEL BLENDS THAT THIS WILL BE A DRY
PERIOD ACROSS OUR FORECAST AREA. THE REMNANTS OF HURRICANE ODILE WILL
BE HEADING NORTHEAST INTO THE TEXAS PANHANDLE AND POSSIBLY INTO FAR
SOUTHWEST KANSAS BY FRIDAY AFTERNOON...BUT STILL OUTSIDE OF OUR
FORECAST AREA. AN UPPER TROUGH COMING OUT OF THE NORTHERN STREAM
WILL BE BREAKING OFF A VORT MAX OVER CALIFORNIA RESULTING IN A LESS
VIGOROUS WAVE FOR OUR FORECAST AREA THAN WAS INDICATED IN MODEL RUNS
24HRS AGO.
FRIDAY NIGHT INTO SATURDAY...THE UPPER TROUGH SWINGING THROUGH THE
PLAINS IS LOOKING LESS IMPRESSIVE WITH RECENT FORECAST RUNS AS SOME
OF THE ENERGY IS BEING LEFT BEHIND OVER CALIFORNIA WHERE IT LEAVES
BEHIND A CUT OFF LOW. MODEL BLENDS HAVE REDUCED POPS SOME IN THIS
PERIOD...AND IT SEEMS JUSTIFIED GIVEN THE SYNOPTIC SITUATION. WILL
HAVE TO REALLY KEEP AN EYE ON THE REMNANTS OF ODILE DURING THIS
PERIOD AS THE REMAINING VORT MAX AND MOISTURE WILL BE COMING UP
THROUGH KANSAS AND MIGHT BE FAR ENOUGH NORTH TO IMPACT OUR CWA.
HOWEVER...THE BETTER BET AT THIS TIME FOR ODILE RELATED
MOISTURE/RAINFALL WILL BE JUST TO THE SOUTH OF OUR FORECAST AREA.
SUNDAY THROUGH TUESDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH GENERALLY DRY WEATHER LIKELY FOR OUR FORECAST
AREA. CAN NOT COMPLETELY RULE OUT A SHORT WAVE SLIDING DOWN INTO OUR
FORECAST AREA ON THE EAST SIDE OF THE RIDGE BY TUESDAY...BUT MOST
AREAS APPEAR DRY AT THIS TIME. HIGH TEMPERATURES WILL BE NEAR NORMAL
AVERAGING OUT IN THE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM CDT WED SEP 17 2014
SKIES WILL BE MAINLY CLEAR TO START THE TAF PERIOD HOWEVER
OVERNIGHT...WITH AN INCREASE IN LLVL MOISTURE LOW CLOUDS WILL
INCREASE/THICKEN WITH LIFR CONDITIONS POSSIBLE. THE POTENTIAL ALSO
EXISTS FOR RESTRICTED VSBYS IN BR/FOG LATE TONIGHT WHICH WILL
LINGER INTO THURSDAY MORNING. VSBYS ARE EXPECTED TO IMPROVE MID
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1145 AM MDT WED SEP 17 2014
.AVIATION...
18Z TAF CYCLE
DEEP ATMOSPHERIC MOISTURE TO REMAIN OVER NORTHERN AND CENTRAL NEW
MEXICO FOR THE NEXT 24 HOURS AS ODILE/S REMAINS TRACK INTO THE REGION.
BANDS OF -RA TO CONTINUE TO MOVE OVER THE REGION WITH ISOLD TO SCT
TSTMS DEVELOPING WHERE CLOUDS TEMPORARILY BREAK. MTS WILL BE
FREQUENTLY OBSCURED IN MVFR TO IFR CIGS/VSBYS ESPECIALLY ALONG
AND SOUTH OF INTERSTATE 40 THROUGH 18/12Z.
&&
.PREV DISCUSSION...406 AM MDT WED SEP 17 2014...
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ODILE WILL CONTINUE TO IMPACT THE
AREA THE REMAINDER OF THE WORK WEEK. RAIN AND EMBEDDED THUNDERSTORMS
WILL BE MOST WIDESPREAD ACROSS CENTRAL AND SOUTHERN AREAS THROUGH
TONIGHT...EXPANDING NORTHEASTWARD AND INTENSIFYING THURSDAY INTO
THURSDAY NIGHT AS THE CORE OF THE REMNANT LOW PASSES OVER THE
HEART OF THE STATE. THE THREAT OF AREAL FLOODING AND POTENTIALLY
LIFE-THREATENING FLASH FLOODING WILL BE GREATEST IN THE SOUTHWESTERN
AND SOUTH CENTRAL MOUNTAINS AND ADJACENT HIGHLANDS BUT LOCALIZED
FLASH FLOODING WILL BE A THREAT AREAWIDE. A SLOW AND GRADUAL
DRYING AND CLEARING TREND IS EXPECTED IN WESTERN NEW MEXICO ON
FRIDAY...BUT EASTERN SECTIONS OF THE STATE COULD CONTINUE TO SEE
SHOWERS AND THUNDERSTORMS WITH A LOCALLY HEAVY RAINFALL THREAT.
FOLLOWING A BRIEF BREAK IN THE SHOWER PATTERN SATURDAY...AN ACTIVE
PATTERN RETURNS EARLY NEXT WEEK.
&&
.DISCUSSION...
ONLY CHANGES TO PREVIOUS FLASH FLOOD WATCH WAS TO EXTEND IT THROUGH
THURSDAY...AND TO ADD THE REMAINDER OF CHAVES COUNTY. FURTHER TIME
AND AREAL EXTENSIONS CAN BE EXPECTED BY LATER SHIFTS TO COVER THURSDAY
NIGHT INTO FRIDAY AS THE EVENT CONTINUES TO UNFOLD.
PER NHC 3AM MDT UPDATE...THE CENTER OF ODILE WAS ABOUT 85 MILES
SOUTH OF PUERTO PENASCO MX AND SLOWLY MOVING NNE AT 6 MPH. A TURN
TOWARD THE NE IS EXPECTED TODAY AS THE TROPICAL CYCLONE RAPIDLY
WEAKENS OVER LAND. THAT PROCESS MAY BE UNDER WAY ALREADY THIS
MORNING WITH EVIDENCE IN WATER VAPOR/INFRARED SATELLITE IMAGERY
THAT THE MID/UPPER CIRCULATION IS BEGINNING TO GET INCREASINGLY SHEARED
NEWD.
THE OFFICIAL TRACK BRINGS THE REMNANT CIRCULATION CLOSE TO TUCSON
LATE THIS EVENING AND THEN INTO OUR SW ZONES SOMETIME THURSDAY
MORNING. THE GFS AND ECMWF ARE PRETTY CLOSE SHOWING THE REMNANT
CIRCULATION OVER CATRON COUNTY NEAR THE NM/AZ LINE BY MIDDAY
THURSDAY. THEREAFTER...SIGNIFICANT TRENDING DIFFERENCES CONTINUE WITH
THE ECMWF KEEPING A BROAD BUT WELL- DEFINED LOW CENTER BETWEEN
FARMINGTON AND ALBUQUERQUE WHILE THE GFS...WHICH APPEARS TO
SUFFER FROM CONVECTIVE FEEDBACK ISSUES IN LATER PERIODS...GENERALLY
DRIVES THE REMNANT CIRCULATION MORE EASTERLY THAN NELY. TRACKING
THE CORE OF THIS REMNANT CIRCULATION WILL BE CRITICAL AS IT WILL
GENERATE TREMENDOUS RAINFALL RATES AS IT CONTRACTS AND INTERACTS
WITH THE COMPLEX TERRAIN OF WC/SW NEW MEXICO. POTENTIAL FOR LIFE-
THREATENING FLOODING/FLASH FLOODING WILL BE GREATEST FOR THE GILA AS WELL
AS BURN SCARS ACROSS LINCOLN COUNTY...BUT THE POTENTIAL FOR
SERIOUS FLASH FLOODING WILL EXIST THROUGH OUT THE CURRENT WATCH
AREA PARTICULARLY LOWLAND AREAS OF SOCORRO/CATRON COUNTIES THAT
HAVE ALREADY RECEIVED SIGNIFICANT RAINFALL.
MEANWHILE...POP PLACEMENT FOR WEST-CENTRAL...MIDDLE RIO GRANDE VALLEY AND
NEIGHBORING CENTRAL HIGHLAND ZONES CONTINUES TO BE CHALLENGING AS
PRECIP BANDS MIGRATING NORTHWARD SEEM TO BE STRUGGLING BENEATH A
BROADLY CONFLUENT FLOW ALOFT. THE LATEST HRRR IS QUITE BULLISH ON
PROSPECT FOR THE ABOVE MENTIONED AREAS AND ESPECIALLY TOWARD
GRANTS/GALLUP AND TRENDED POP UPWARD CLOSER TO MAV GUIDANCE.
OTHERWISE...NOT CONVINCED WE WILL SEE WIDESPREAD/NUMEROUS
THUNDERSTORM ACTIVITY OVER SC/SW ZONES TODAY GIVEN THE LACK OF
STRONG SURFACE HEATING/INSTABILITY BUT THE WRF/HRRR DO SUGGEST A
SIGNIFICANT INCREASE IN CONVECTIVE PRECIP FOR THE SE PLAINS LATER
TODAY/EVENING.
LINGERING TROPICAL MOISTURE AND MORE SUNSHINE MAY SPELL A MORE
ACTIVE DAY ON FRIDAY ACROSS THE CENTRAL/WEST THAN CURRENTLY
ADVERTISED BUT TRENDING LESS ACTIVE BY SATURDAY BEFORE NEXT UPTICK
IN SHOWER/STORM COVERAGE SUNDAY/MONDAY. SEE BELOW FOR A MORE DETAILED
EXTENDED ANALYSIS. KJ
&&
.FIRE WEATHER...
MODELS CONTINUE TO HAVE GOOD AGREEMENT ON THE REMNANTS OF NOW
TROPICAL STORM ODILE TRACKING NORTHEASTWARD FROM THE UPPER GULF OF
CALIFORNIA ACROSS THE FIRE WEATHER FORECAST AREA TODAY THROUGH
FRIDAY. ONCE THE SYSTEM BECOMES EXTRATROPICAL...THE CENTER OF UPPER
LEVEL LOW PRESSURE IS PROGGED TO TRACK NORTHEASTWARD OVER TUCSON
TONIGHT...GALLUP THURSDAY...THEN CHAMA/TAOS ON FRIDAY. THIS WILL
PLACE SOUTHWEST/WEST CENTRAL...CENTRAL...THEN NORTHEAST PARTS OF THE
FORECAST AREA UNDER ROBUST DYNAMICS FOR LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE FOREBODING PRECIPITATION FORECAST FROM THE
WEATHER PREDICTION CENTER CALLS FOR AN ADDITIONAL 2 TO 6 INCHES OF
RAIN FROM THE GALLINAS MOUNTAINS WESTWARD ACROSS SOCORRO COUNTY AND
THE WEST CENTRAL HIGHLANDS. AMOUNTS TREND GRADUALLY DOWNWARD NORTH
AND NORTHEASTWARD WITH 1 INCH ACCUMULATIONS POSSIBLE AS FAR NORTH AS THE
SOUTHERN CHUSKAS...THE BRAZOS AND CLAYTON. EXCEPT FOR THE FOUR
CORNERS REGION...THE WHOLE FORECAST AREA HAS A GOOD SHOT OF WETTING
PRECIPITATION THIS WEEK. IT MAY TAKE TIL THURSDAY NIGHT AND FRIDAY
FOR SIGNIFICANT PRECIP TO REACH THE NORTHERN BORDER.
IN THE WAKE OF ODILES REMNANTS MODELS AGREE BETTER ON AN UPPER LEVEL
LOW PRESSURE SYSTEM STALLING OFF THE CA COAST FRIDAY NIGHT AND
SATURDAY. THEY THEN DIVERGE IN TRACK AND TIMING WITH THE STORM EJECTING
NORTHEASTWARD EITHER ACROSS THE CENTRAL OR NORTHERN ROCKIES LATE IN
THE WEEKEND AND EARLY IN THE COMING WEEK. HOWEVER...MODELS DO
GENERALLY AGREE ON THE SYSTEM DRAWING A BACK DOOR COLD FRONT INTO
THE FORECAST AREA FROM THE NE FRIDAY NIGHT AND INTO AZ SATURDAY
NIGHT. THIS MAY RESULT IN A FAIRLY STRONG EAST CANYON WIND IN THE
RIO GRANDE VALLEY SATURDAY NIGHT. HUMIDITIES SHOULD TREND DOWNWARD
BY 10 TO 20 PERCENT ON SATURDAY...ONLY TO REBOUND A FEW TO 16
PERCENT ON SUNDAY BEHIND THE COLD FRONT. WITH THE DECREASE IN
MOISTURE THERE WILL BE A SIGNIFICANT DOWNTICK IN THUNDERSTORM
COVERAGE ON SATURDAY. THEN...THE CHANCE FOR THUNDERSTORMS WILL TREND
UPWARD AGAIN SUNDAY INTO THE COMING WORK WEEK AS THE UPPER LOW
PASSING NORTH OF NM DRAWS A ROBUST MONSOON MOISTURE PLUME NORTHWARD
OVER THE STATE. AT THIS TIME...CENTRAL AND WESTERN AREAS LOOK
FAVORED FOR WETTING THUNDERSTORM CHANCES SUNDAY AND MONDAY. THE
MOISTURE PLUME MAY THEN FAVOR CENTRAL AND EASTERN AREAS FOR WETTING
PRECIPITATION TUESDAY...DEPENDING ON THE TRACK OF THE UPPER LOW AND
HOW QUICKLY IT EXITS THE ROCKIES ONTO THE PLAINS.
WITH BANDS OF PRECIPITATION LIKELY TO TRACK NORTHWARD INTO THE
FORECAST AREA TODAY AND THURSDAY...HIGH TEMPERATURES SHOULD VARY A
FEW TO 11 DEGREES BELOW NORMAL. NEAR TO ABOVE NORMAL READINGS ARE
EXPECTED ALONG THE NORTHERN BORDER. LOW TEMPERATURES DURING THIS
PERIOD SHOULD REMAIN ABOVE NORMAL DUE TO GENERALLY SOUTHERLY FLOW
AND OVERNIGHT CLOUD COVER. TEMPERATURES SHOULD BEGIN TO REBOUND
TOWARD NORMAL ON FRIDAY...EXCEPT PERHAPS ACROSS THE EAST WHERE SOME
OF THE BETTER SUBTROPICAL MOISTURE MAY LINGER. HIGH TEMPS SHOULD
THEN REACH NEAR AND ABOVE NORMAL AREAWIDE ON SATURDAY...ONLY TO DROP
AGAIN ON SUNDAY IN THE WAKE OF THE COLD FRONT.
IN ADDITION...POCKETS OF POOR VENTILATION ARE FORECAST
TODAY...FRIDAY...MONDAY AND TUESDAY...WITH SOME IMPROVEMENT
THURSDAY...SATURDAY AND SUNDAY. MEAGER HAINES VALUES ARE ALSO
EXPECTED OVER THE NEXT 7 DAYS. 44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ508-509-520-524>526-538>540.
&&
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
401 PM CDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
PICTURE PERFECT WEATHER CONDITIONS ACROSS THE REGION THIS AFTERNOON
AS TEMPERATURES HAVE RISEN INTO THE 70S AND WINDS REMAIN LIGHT.
ONLY MINOR FORECAST CONCERNS THROUGH THE DAYBREAK HOURS. MINOR
SHORTWAVE OVER EASTERN MONTANA WILL DROP SOUTHEAST LATER THIS
EVENING. LATEST HRRR AND HOPWRF RUNS INDICATING THIS WAVE SHOULD
BEGIN PRODUCING WIDELY SCATTERED SHOWERS AS IT MOVES INTO THE AREA.
GENERALLY THESE WILL BE HIGH-BASED SHOWERS...AND GIVEN A RATHER
SUBSTANTIAL DRY SUB-CLOUD LAYER...ANTICIPATE A CONSIDERABLE
AMOUNT OF VIRGA OR A FEW SPRINKLES MAINLY WEST OF I-29 THROUGH
MIDNIGHT.
THE PASSAGE OF THIS UPPER WAVE WILL ALLOW A WEAK SURFACE BOUNDARY TO
DRIFT NORTHWARD EARLY TOMORROW MORNING..WITH LOW-LEVEL MOISTURE
STEADILY ADVECTING NORTHWARD. SHOULD SEE STRATUS DEVELOPMENT TOWARDS
DAYBREAK...AND CANNOT RULE OUT PATCHY FOG ESPECIALLY ALONG EDGE OF
ADVANCING STRATUS. LOW LEVEL ISENTROPIC PLOTS SHOW VERY WEAK LIFT
WITHIN THE CLOUD LAYER...BUT FEEL LIFT TOO WEAK TO SUPPORT DRIZZLE.
CLOUDS ARE EXPECTED TO HANG AROUND FOR MUCH OF THURSDAY...GRADUALLY
LIFTING AND SCATTERING IN THE AFTERNOON. TEMPERATURES WILL REMAIN
IN THE 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
LITTLE DOUBT THAT EXTENSIVE STRATUS WILL EXPAND/DEVELOP THURSDAY
NIGHT INTO EARLY FRIDAY WITH ENHANCED LOW LEVEL JET AND STRENGTHENING
INVERSION. FOG A BIT MORE PROBLEMATIC...LIKELY FAVORING WESTERN
EDGE OF THE CLOUD AREA...AND NEAR SURFACE SOUTHEAST TO SOUTH FLOW
PROVIDING INCREASING MOISTURE. SREF PROBABILITIES OF LOW CLOUDS
ARE EXTREMELY HIGH...BUT MODEST IN THE REALM OF LOWEST
VISIBILITIES...GENERALLY SUPPORTING THIS EXPECTATION. NOT TOO
ENTHUSIASTIC ABOUT PRECIPITATION CHANCES...ESPECIALLY IN THE
EVENING. A LITTLE ENHANCEMENT OF LIFT ON LEADING EDGE OF THE
WARMING TEMPS ALOFT OCCURS ACROSS NORTHEAST NEBRASKA BY AROUND
06Z...AND COULD BE JUST ENOUGH ELEVATED FORCING AND WEAK
INSTABILITY TO SHAKE OUT AN ISOLATED THUNDERSTORM HEADING THROUGH
SOUTHWEST MINNESOTA AND NORTHWEST IOWA ALONG ELEVATED THETA E
ADVECTION ZONE.
IF NOT FOR A MINIMAL CHANCE OF A SHOWER OR THUNDERSTORM LINGERING
EARLY FRIDAY IN THE FAR EAST/NORTHEAST...FRIDAY WILL BE A CAPPED
DAY AS TEMPS 800-750 HPA TEMPS WARM TO +15 TO +22C...WITH THE
MAIN BATTLE OF THE DAY OVER MAX TEMPERATURES SET BETWEEN THE
STRATUS AND THE SOUTHWESTERLY FLOW ALOFT. TREND HAS BEEN TO SLOW
DOWN THE EASTWARD PROGRESSION...WITH EARLY DAY CLOUDS AT LEAST
BACK TO WEST OF THE JAMES RIVER...AND PERHAPS HOLDING TOUGH INTO
VERY EARLY AFTERNOON TOWARD I 29. SHOULD EVENTUALLY CLEAR WITH
GOOD PUSH FROM WESTERLY COMPONENT AHEAD OF ADVANCING FRONTAL ZONE
REACHING THE FAR WESTERN CWA BY LATE DAY. ENOUGH INTERFERENCE
EARLY IN THE DAY EAST TO HOLD READINGS CLOSER TO 80 DEGREES...BUT
SOME AREAS TO THE WEST TOWARD LOWER JAMES AND LOWER BRULE WILL
GIVE A GOOD RUN AT UPPER 80S TO NEAR 90.
PRECIPITATION SHOULD BE EXCLUSIVELY POST FRONTAL ON FRIDAY
NIGHT...SOMEWHAT SCARCE EARLY ON...BUT GRADUALLY TAKING HOLD WITH
DEEPER POST FRONTAL QG LIFT...AND PERHAPS A LITTLE MID LEVEL
WEAK CONTRIBUTION TO MOISTURE BY THE TIME DEFORMATION REACHES THE
SOUTHEASTERN HALF OF THE CWA LATER AT NIGHT. NOT LOOKING FOR ANY
SEVERE STORMS WITH INSTABILITY LIMITED...AND EFFECTIVE SHEAR
REDUCED BY NOCTURNAL DECOUPLING AND THE DEGREE OF WESTERLY
PREFRONTAL COMPONENT.
BEHIND ANY LINGERING SHOWERS/THUNDER SATURDAY MORNING...LOOKS TO
BE A WELL-MIXED DAY...AND WITH MAIN COOLING HOLDING OFF UNTIL
SECONDARY WAVE PASSAGE TO THE EAST ON SATURDAY EVENING... WILL
LIKELY BE A FAIRLY WARM DAY...AND LAST ABOVE NORMAL FOR A FEW
DAYS. MIXING WOULD FAVOR MAINLY UPPER 70S TO LOWER 80S...ALONG
WITH BRISK MIDDAY AND AFTERNOON WINDS OF 15 TO 25 MPH.
FOR SUNDAY THROUGH WEDNESDAY...LOOKS LIKE A FAIRLY QUIET TIME
AS FLOW AMPLIFIES A BIT INTO EARLY WEEK WITH WESTERN RIDGE AND
EASTERN TROUGH...THEN WEAKENS AND TRANSLATES EASTWARD AS SEVERAL
SOLUTIONS INDICATE A WESTERN TROUGH PROGRESSING INTO THE AREA BY
LATER TUESDAY OR EARLY WEDNESDAY. WOULD NOT BE SURPRISED TO NEED
TO ADD IN A THREAT FOR SHOWER/THUNDER FOR TUESDAY NIGHT INTO
WEDNESDAY...BUT TIMING AND LOCATION OF UPPER TROUGH IN FLUX AT
THIS POINT AND NOT WORTH CLUTTERING UP THE FORECAST...ESPECIALLY
CONSIDERING THE RUN TO RUN SIGNIFICANT CHANGES IN MODELS OVER LAST
24 HOURS. STRETCHED OUT DIURNAL RANGE JUST A TOUCH ON MONDAY AND
TUESDAY WITH DRY SURFACE RIDGE SLIPPING THROUGH THE AREA...AND
MAINTAINING A TRAJECTORY INTO THE EAST ON TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1159 AM CDT WED SEP 17 2014
EASTERLY WINDS WILL PREVAIL INTO THE EVENING HOURS...BEFORE
TURNING MORE SOUTHERLY AFTER MIDNIGHT. SCATTERED CU FIELD LIKELY
THIS AFTERNOON...WITH MODELS SUGGESTING A SCATTERED 10K FT AGL
DECK MOVING IN THIS EVENING AS WEAK SHORTWAVE PASSES THROUGH.
MODELS STILL SUGGEST LOW LEVEL MVFR/IFR STRATUS DEVELOPING TOWARD
DAYBREAK WITH LOCALIZED MVFR VISIBILITY RESTRICTIONS...WHICH WILL
GRADUALLY LIFT THROUGH THE MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...DUX
LONG TERM...CHAPMAN
AVIATION...DUX
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1239 PM CDT WED SEP 17 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...A LITTLE STRONGER SOUTHERLY FLOW IS PRODUCING AN
EXTENSIVE CUMULUS FIELD ALONG AND EAST HIGHWAY 77. FLIGHT
CATEGORIES ARE DOMINATE VFR WITHIN THIS CLOUD FIELD BUT COULD
BRIEFLY TOUCH MVFR AROUND 2500-3000 FEET. ISOLATED CONVECTION IS
POSSIBLE BUT CHANCES HAVE BEEN REDUCED THIS AFTERNOON BUT REMAIN
HIGHEST ALONG AND EAST OF THE COASTLINE. WESTERN AREAS WILL
EXPERIENCE GOOD FLYING CONDITIONS WITH FEW-SCT CLOUDS. WEAK
SURFACE INVERSION DEVELOPS OVERNIGHT WITH STRATUS DEVELOPING LATE
OR A FEW HOURS EITHER SIDE OF SUNRISE. BEST PROBABILITIES FOR MVFR
CIGS WILL BE WEST OF HIGHWAY 77 WITH BRIEF IMPACTS AT KMFE AND
POSSIBLY AT KHRL THURSDAY MORNING. MODERATE SOUTH TO SOUTHEAST
WINDS THIS AFTERNOON AND INTO THE EVENING WITH SOME GUSTS
APPROACHING 20 KNOTS MAYBE A LITTLE STRONGER THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1133 AM CDT WED SEP 17 2014/
DISCUSSION...REDUCED POPS FOR THIS AFTERNOON WITH HIGH PRESSURE
BUILDING ACROSS NORTHEAST MEXICO AND SOUTHWEST PORTIONS OF DEEP
SOUTH TEXAS. FORECAST SOUNDINGS INDICATE SOME WARMING TAKING PLACE
BETWEEN 850-700MB THIS AFTERNOON AND SOUTHERLY WINDS NOT
CONDUCIVE FOR THE SEA BREEZE TO MAKE HEADWAY TOO FAR WEST. RAP AND
SREF AS WELL AS A CONSALL MODEL BLEND KEEP THE BEST CHANCES ALONG
THE COASTAL COUNTIES WITH KENEDY COUNTY HAVE THE HIGHEST CHANCES.
ADJUSTED CLOUD COVER AS WELL TO ACCOMMODATE WHERE POPS ARE MORE
LIKELY TO DEVELOP. TEMPERATURES LOOK WITHIN THE BALL PARK WITH NO
CHANGES AT THIS TIME. NEW TEMP/POP TABLE BELOW.
PREV DISCUSSION... /ISSUED 606 AM CDT WED SEP 17 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR TAFS NEXT 24 HOURS. RADAR IS QUIETER THIS MORNING
WITH ONLY A FEW MARINE SHOWERS DEPICTED. LOOKING AT JUST A FEW
MID VALLEY LOW CLOUDS FROM OBSERVATIONS AND JUST A FEW HIGH
CLOUDS ON SATELLITE ORIGINATING FROM TROPICAL STORM ODILE IN THE
NORTHERN GULF OF CALIFORNIA. PATCHY LIGHT FOG IN A FEW SPOTS IS
NOT SIGNIFICANT. OTHERWISE...LIGHT SOUTH SOUTHEAST WINDS EXPECTED
TODAY...WITH SCT TO BKN LOW CLOUDS MOSTLY ABOVE 3 KFT BY LATE
MORNING DUE TO AMPLE RESIDUAL LOW LEVEL MOISTURE. MID LEVEL
RIDGING OVERHEAD WILL HELP STABILIZE THE ATMOSPHERE...BUT ISOLD
SHOWERS MAY STILL DEVELOP TODAY...INCLUDING ALONG THE SEA BREEZE.
PREV DISCUSSION... /ISSUED 334 AM CDT WED SEP 17 2014/
SHORT TERM /TODAY THROUGH THURSDAY/...COLUMN MOISTURE WILL REMAIN
ELEVATED ACROSS DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY THROUGH
THE SHORT TERM...WITH PWAT HOVERING AROUND TWO INCHES. MID LEVEL
RIDGING OVERHEAD...SUPPORTING HIGH PRESSURE OVER THE NORTHWEST
GULF...WILL TEND TO STABILIZE WEATHER CONDITIONS HOWEVER...WITH A
SITUATION MORE LIKELY TO SUPPORT A SEA BREEZE RATHER THAN WIDESPREAD
PRECIP. NONETHELESS...A FEW HEAVIER SHOWERS COULD DEVELOP...WHICH
COULD BE OF CONCERN TO AREAS WHICH RECENTLY RECEIVED A LOT OF RAIN.
MID LEVEL RIDGING WILL SLOWLY SUCCEED IN DEVELOPING SOME SUBSIDENCE
AND INHIBITION IN THE SOUNDING...AND FEEL THAT TODAY MIGHT BE BETTER
FOR WESTWARD MVG SEA BREEZE CONVECTION THAN TOMORROW...BUT ANOTHER
SEA BREEZE ROUND WILL STILL BE POSSIBLE ON THURSDAY. SHOULD SEE A
MIX OF CLOUDS AND SUN TODAY WITH NEAR NORMAL TEMPS AND LIGHT TO
MODERATE SOUTH SOUTHEAST WINDS. A FEW HIGH CLOUDS ORIGINATING WITH
ODILE WILL STILL BE IN THE MIX. MID 70S WILL BE ON TAP TONIGHT WITH
A FEW MORE LOW CLDS DUE TO WINDS BACKING A BIT TO A MORE SOUTHEAST
ONSHORE FLOW. LOOK FOR INCREASED LOW CLOUDS THURSDAY DUE TO A WEAK
CAP BUT STILL PARTLY CLOUDY WITH MODERATE SOUTHEAST WINDS. TEMPS
WILL AGAIN BE NEAR NORMAL. MAINTAINED MUCH OF THE INHERITED FORECAST
PACKAGE...BUT TRENDED POPS DOWN JUST A WEE BIT...10 PERCENT HERE AND
THERE...BASED ON MORE STABILITY AND A LESSER SOURCE OF MOISTURE FROM
THE SOUTH. USED A BLEND FOR TEMPS BUT BUMPED UP HIGH TEMPS A DEGREE
FROM THE BLEND BASED ON TUESDAY`S PERFORMANCE AND CHANCE OF SEEING
SOME SUN AGAIN TODAY.
LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THURSDAY NIGHT INTO FRIDAY WE WILL RETAIN RICH COLUMN MOISTURE WITH
850-700MB RH VALUES OVER 70 PERCENT. NORTHWESTERLY 300-500MB FLOW
WILL DEVELOP AS RIDGING DEVELOPS IN THAT LAYER OVER WEST/CENTRAL
TEXAS AND NORTHERN MEXICO. EMBEDDED IN THIS FLOW IS WEAK
PERTURBATIONS AND RESIDUAL MOISTURE FROM THE REMNANTS OF ODILE. LOW
LEVEL FLOW WILL BE MODERATE OUT OF THE SOUTHEAST. KEPT 20 TO 30 PCT
POPS IN THE FORECAST IN THE MORNING HOURS INCREASING TO 40 PCT VALLEY
WIDE IN THE AFTERNOON WITH 50 PCT OVER THE RANCHLANDS WHERE SLIGHTLY
BETTER MID LEVEL ASCENT IS FORECAST TO BE IN PLACE ENHANCING
SEABREEZE CONVERGENCE. PRECIPITABLE WATER VALUES AROUND 2.0 TO 2.2
INCHES WILL POSITION ANY CELL THAT GETS GOING TO BE A VERY HEAVY
RAINFALL PRODUCER...ALTHOUGH STORM MOTION AND COVERAGE SHOULD
PREVENT A WIDESPREAD FLOODING RISK...ASSUMING LIMITED CONVECTIVE
COVERAGE IN THE DAYS LEADING UP TO FRIDAY.
SATURDAY THE GFS DISRUPTS THE EAST TO SOUTHEAST 850 TO 700MB
MOISTURE TAP FROM THE GULF OF MEXICO WHILE THE ECMWF KEEPS ABOUT 10
TO 15 KNOT FLOW GOING. BOTH SEEM TO BE KEYING IN ON WEAK WAVES
DEVELOPED BY CONVECTION OVER BELIZE AND THE YUCATAN. THE ECMWF
APPEARS TO HAVE A BETTER HANDLE BASED ON HOW THESE SYSTEMS HAVE
BEHAVED THIS SEASON AND LEANED THE FORECAST IN THE DIRECTION OF THE
ECMWF...WHICH MATCHES WITH THE EXISTING FORECAST WELL. THIS CALLS
FOR LOW POPS IN THE MORNING PEAKING IN THE AFTERNOON AT 20 TO 30 PCT.
SUNDAY AND MONDAY THE SYNOPTIC PATTERN REMAINS LITTLE CHANGED. MID
LEVEL RIDGING PERSISTS OVER NORTHERN MEXICO AND CENTRAL TEXAS. WE
REMAIN IN MOIST 850-700MB SOUTHEASTERLY TO EASTERLY FLOW WITH NO
REAL DISCERNIBLE WAVES TO ENHANCE SHOWERS/STORMS. WENT WITH POP
PATTERN FAVORING OVERNIGHT SHOWERS ON THE GULF OF MEXICO WORKING
INTO SEABREEZE INITIATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON
WITH 30 PCT POPS IN THE FAVORED ZONES...BASICALLY VALLEY WIDE SUNDAY
AND IN A RAYMONDVILLE/HEBBRONVILLE/FALFURRIAS TRIANGLE ON MONDAY
SURROUNDED BY 20 PCT POPS. THIS IS BELOW GUIDANCE CONSENSUS BUT
PERSISTENT 500MB SUBSIDENCE IN THE VICINITY WILL LIKELY LIMIT MID
LEVEL LAPSE RATES AND INSTABILITY AND ULTIMATELY CONVECTIVE COVERAGE
BY MAKING NEW UPDRAFTS FIGHT A MORE HOSTILE AIRMASS.
TUESDAY THE ECMWF PUSHES A FRONT INTO THE AREA FROM THE NORTHWEST
WHILE THE GFS HOLDS OFF. THE ECMWF IS SLOWER AND MORE AMPLIFIED WITH
RIDGING OVER THE DAKOTAS WHICH ULTIMATELY HELPS PUSH THE FRONT
THROUGH THE AREA. THE GFS BRINGS A JET MAX INTO THE PACIFIC
NORTHWEST FROM NEARLY DUE WEST WHILE THE ECMWF IS MORE AMPLIFIED
WHICH BETTER AGREES WITH THE ONGOING PATTERN OVER THE CENTRAL AND
NORTHWEST CONUS. GFS ENSEMBLE MEMBERS ALSO LEAN IN A SLIGHT MAJORITY
TOWARDS THE MORE NORTHWESTWARD ORIENTED SPEED MAX WHICH LENDS
CREDIBILITY TO THE ECMWF SOLUTION WHICH IS LESS PROGRESSIVE AND
STRONGER WITH RIDGING THAT RESULTS IN THE FRONT PUSHING THROUGH.
INTRODUCED 20/SLIGHT CHANCE POPS ON TUESDAY GIVEN THE PRESENCE OF
THE FRONT. THIS IS BELOW GUIDANCE CONSENSUS BUT RUN TO RUN
CONTINUITY HAS BEEN POOR OVER THE LAST FEW RUNS.
WEDNESDAY THE GFS SENDS A FAIRLY ROBUST COLD FRONT THROUGH THE AREA
WHILE THE ECMWF HOLDS OFF. THE ECMWF IS SLOWER AND LESS AMPLIFIED
WITH A 300MB WEST TEXAS TROUGH WHILE THE GFS SHOWS AN
ANOMALOUSLY STRONG TROUGH WHICH GENERATES A WEST TEXAS SFC CYCLONE
THAT RIDES OVER A STALLED FRONT IN THE AREA PRODUCING WIDESPREAD
RAINFALL. THE ECMWF HOLDS UP BETTER RUN TO RUN AND GIVEN THE ANOMALOUS
STRENGTH OF THE 00Z GFS TROUGH WENT WITH THAT FOR THE FORECAST JUST
HOLDING A SLIGHT CHANCE OF SHOWERS IN THE FORECAST. A SHIFT THOUGH
TOWARDS A FINAL GFS SOLUTION WILL RESULT IN SIGNIFICANT INCREASES IN
RAIN CHANCES BY THE MIDDLE OF NEXT WEEK. /68-JGG/
MARINE...
TODAY THROUGH THURSDAY...BROAD HIGH PRESSURE OVER THE NORTH WEST
GULF WILL SUPPORT LIGHT TO MODERATE SOUTH SOUTHEAST WINDS THROUGH
THE SHORT TERM PERIOD. TWO TO FOUR FEET SEAS WILL PERSIST ON THE
GULF...WITH A LGT TO MODERATE CHOP ON THE BAY. AN ISOLATED MARINE
SHOWER MAY DEVELOP FROM TIME TO TIME.
THURSDAY NIGHT THROUGH MONDAY...
MODERATE EAST TO SOUTHEAST FLOW AND LOW TO MODERATE SEAS ARE
FORECAST THURSDAY NIGHT THROUGH MONDAY ALONG THE LOWER TEXAS COAST.
MORNING SHOWER AND THUNDERSTORM CHANCES WILL PERSIST THROUGH THE DAY
BUT WIDESPREAD SHOWERS AND THUNDERSTORMS ARE NOT CURRENTLY FORECAST.
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW EXERCISE CAUTION LEVELS
FOR THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 90 80 90 79 / 20 20 40 20
BROWNSVILLE 91 78 91 78 / 20 20 40 20
HARLINGEN 92 78 93 77 / 20 20 40 20
MCALLEN 94 78 94 78 / 10 10 30 20
RIO GRANDE CITY 94 77 95 78 / 10 10 20 20
SOUTH PADRE ISLAND 87 81 87 80 / 30 20 30 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
59/58
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1133 AM CDT WED SEP 17 2014
.DISCUSSION...REDUCED POPS FOR THIS AFTERNOON WITH HIGH PRESSURE
BUILDING ACROSS NORTHEAST MEXICO AND SOUTHWEST PORTIONS OF DEEP
SOUTH TEXAS. FORECAST SOUNDINGS INDICATE SOME WARMING TAKING PLACE
BETWEEN 850-700MB THIS AFTERNOON AND SOUTHERLY WINDS NOT
CONDUCIVE FOR THE SEA BREEZE TO MAKE HEADWAY TOO FAR WEST. RAP AND
SREF AS WELL AS A CONSALL MODEL BLEND KEEP THE BEST CHANCES ALONG
THE COASTAL COUNTIES WITH KENEDY COUNTY HAVE THE HIGHEST CHANCES.
ADJUSTED CLOUD COVER AS WELL TO ACCOMMODATE WHERE POPS ARE MORE
LIKELY TO DEVELOP. TEMPERATURES LOOK WITHIN THE BALL PARK WITH NO
CHANGES AT THIS TIME. NEW TEMP/POP TABLE BELOW.
&&
.PREV DISCUSSION... /ISSUED 606 AM CDT WED SEP 17 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR TAFS NEXT 24 HOURS. RADAR IS QUIETER THIS MORNING
WITH ONLY A FEW MARINE SHOWERS DEPICTED. LOOKING AT JUST A FEW
MID VALLEY LOW CLOUDS FROM OBSERVATIONS AND JUST A FEW HIGH
CLOUDS ON SATELLITE ORIGINATING FROM TROPICAL STORM ODILE IN THE
NORTHERN GULF OF CALIFORNIA. PATCHY LIGHT FOG IN A FEW SPOTS IS
NOT SIGNIFICANT. OTHERWISE...LIGHT SOUTH SOUTHEAST WINDS EXPECTED
TODAY...WITH SCT TO BKN LOW CLOUDS MOSTLY ABOVE 3 KFT BY LATE
MORNING DUE TO AMPLE RESIDUAL LOW LEVEL MOISTURE. MID LEVEL
RIDGING OVERHEAD WILL HELP STABILIZE THE ATMOSPHERE...BUT ISOLD
SHOWERS MAY STILL DEVELOP TODAY...INCLUDING ALONG THE SEA BREEZE.
PREV DISCUSSION... /ISSUED 334 AM CDT WED SEP 17 2014/
SHORT TERM /TODAY THROUGH THURSDAY/...COLUMN MOISTURE WILL REMAIN
ELEVATED ACROSS DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY THROUGH
THE SHORT TERM...WITH PWAT HOVERING AROUND TWO INCHES. MID LEVEL
RIDGING OVERHEAD...SUPPORTING HIGH PRESSURE OVER THE NORTHWEST
GULF...WILL TEND TO STABILIZE WEATHER CONDITIONS HOWEVER...WITH A
SITUATION MORE LIKELY TO SUPPORT A SEA BREEZE RATHER THAN WIDESPREAD
PRECIP. NONETHELESS...A FEW HEAVIER SHOWERS COULD DEVELOP...WHICH
COULD BE OF CONCERN TO AREAS WHICH RECENTLY RECEIVED A LOT OF RAIN.
MID LEVEL RIDGING WILL SLOWLY SUCCEED IN DEVELOPING SOME SUBSIDENCE
AND INHIBITION IN THE SOUNDING...AND FEEL THAT TODAY MIGHT BE BETTER
FOR WESTWARD MVG SEA BREEZE CONVECTION THAN TOMORROW...BUT ANOTHER
SEA BREEZE ROUND WILL STILL BE POSSIBLE ON THURSDAY. SHOULD SEE A
MIX OF CLOUDS AND SUN TODAY WITH NEAR NORMAL TEMPS AND LIGHT TO
MODERATE SOUTH SOUTHEAST WINDS. A FEW HIGH CLOUDS ORIGINATING WITH
ODILE WILL STILL BE IN THE MIX. MID 70S WILL BE ON TAP TONIGHT WITH
A FEW MORE LOW CLDS DUE TO WINDS BACKING A BIT TO A MORE SOUTHEAST
ONSHORE FLOW. LOOK FOR INCREASED LOW CLOUDS THURSDAY DUE TO A WEAK
CAP BUT STILL PARTLY CLOUDY WITH MODERATE SOUTHEAST WINDS. TEMPS
WILL AGAIN BE NEAR NORMAL. MAINTAINED MUCH OF THE INHERITED FORECAST
PACKAGE...BUT TRENDED POPS DOWN JUST A WEE BIT...10 PERCENT HERE AND
THERE...BASED ON MORE STABILITY AND A LESSER SOURCE OF MOISTURE FROM
THE SOUTH. USED A BLEND FOR TEMPS BUT BUMPED UP HIGH TEMPS A DEGREE
FROM THE BLEND BASED ON TUESDAY`S PERFORMANCE AND CHANCE OF SEEING
SOME SUN AGAIN TODAY.
LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THURSDAY NIGHT INTO FRIDAY WE WILL RETAIN RICH COLUMN MOISTURE WITH
850-700MB RH VALUES OVER 70 PERCENT. NORTHWESTERLY 300-500MB FLOW
WILL DEVELOP AS RIDGING DEVELOPS IN THAT LAYER OVER WEST/CENTRAL
TEXAS AND NORTHERN MEXICO. EMBEDDED IN THIS FLOW IS WEAK
PERTURBATIONS AND RESIDUAL MOISTURE FROM THE REMNANTS OF ODILE. LOW
LEVEL FLOW WILL BE MODERATE OUT OF THE SOUTHEAST. KEPT 20 TO 30 PCT
POPS IN THE FORECAST IN THE MORNING HOURS INCREASING TO 40 PCT VALLEY
WIDE IN THE AFTERNOON WITH 50 PCT OVER THE RANCHLANDS WHERE SLIGHTLY
BETTER MID LEVEL ASCENT IS FORECAST TO BE IN PLACE ENHANCING
SEABREEZE CONVERGENCE. PRECIPITABLE WATER VALUES AROUND 2.0 TO 2.2
INCHES WILL POSITION ANY CELL THAT GETS GOING TO BE A VERY HEAVY
RAINFALL PRODUCER...ALTHOUGH STORM MOTION AND COVERAGE SHOULD
PREVENT A WIDESPREAD FLOODING RISK...ASSUMING LIMITED CONVECTIVE
COVERAGE IN THE DAYS LEADING UP TO FRIDAY.
SATURDAY THE GFS DISRUPTS THE EAST TO SOUTHEAST 850 TO 700MB
MOISTURE TAP FROM THE GULF OF MEXICO WHILE THE ECMWF KEEPS ABOUT 10
TO 15 KNOT FLOW GOING. BOTH SEEM TO BE KEYING IN ON WEAK WAVES
DEVELOPED BY CONVECTION OVER BELIZE AND THE YUCATAN. THE ECMWF
APPEARS TO HAVE A BETTER HANDLE BASED ON HOW THESE SYSTEMS HAVE
BEHAVED THIS SEASON AND LEANED THE FORECAST IN THE DIRECTION OF THE
ECMWF...WHICH MATCHES WITH THE EXISTING FORECAST WELL. THIS CALLS
FOR LOW POPS IN THE MORNING PEAKING IN THE AFTERNOON AT 20 TO 30 PCT.
SUNDAY AND MONDAY THE SYNOPTIC PATTERN REMAINS LITTLE CHANGED. MID
LEVEL RIDGING PERSISTS OVER NORTHERN MEXICO AND CENTRAL TEXAS. WE
REMAIN IN MOIST 850-700MB SOUTHEASTERLY TO EASTERLY FLOW WITH NO
REAL DISCERNIBLE WAVES TO ENHANCE SHOWERS/STORMS. WENT WITH POP
PATTERN FAVORING OVERNIGHT SHOWERS ON THE GULF OF MEXICO WORKING
INTO SEABREEZE INITIATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON
WITH 30 PCT POPS IN THE FAVORED ZONES...BASICALLY VALLEY WIDE SUNDAY
AND IN A RAYMONDVILLE/HEBBRONVILLE/FALFURRIAS TRIANGLE ON MONDAY
SURROUNDED BY 20 PCT POPS. THIS IS BELOW GUIDANCE CONSENSUS BUT
PERSISTENT 500MB SUBSIDENCE IN THE VICINITY WILL LIKELY LIMIT MID
LEVEL LAPSE RATES AND INSTABILITY AND ULTIMATELY CONVECTIVE COVERAGE
BY MAKING NEW UPDRAFTS FIGHT A MORE HOSTILE AIRMASS.
TUESDAY THE ECMWF PUSHES A FRONT INTO THE AREA FROM THE NORTHWEST
WHILE THE GFS HOLDS OFF. THE ECMWF IS SLOWER AND MORE AMPLIFIED WITH
RIDGING OVER THE DAKOTAS WHICH ULTIMATELY HELPS PUSH THE FRONT
THROUGH THE AREA. THE GFS BRINGS A JET MAX INTO THE PACIFIC
NORTHWEST FROM NEARLY DUE WEST WHILE THE ECMWF IS MORE AMPLIFIED
WHICH BETTER AGREES WITH THE ONGOING PATTERN OVER THE CENTRAL AND
NORTHWEST CONUS. GFS ENSEMBLE MEMBERS ALSO LEAN IN A SLIGHT MAJORITY
TOWARDS THE MORE NORTHWESTWARD ORIENTED SPEED MAX WHICH LENDS
CREDIBILITY TO THE ECMWF SOLUTION WHICH IS LESS PROGRESSIVE AND
STRONGER WITH RIDGING THAT RESULTS IN THE FRONT PUSHING THROUGH.
INTRODUCED 20/SLIGHT CHANCE POPS ON TUESDAY GIVEN THE PRESENCE OF
THE FRONT. THIS IS BELOW GUIDANCE CONSENSUS BUT RUN TO RUN
CONTINUITY HAS BEEN POOR OVER THE LAST FEW RUNS.
WEDNESDAY THE GFS SENDS A FAIRLY ROBUST COLD FRONT THROUGH THE AREA
WHILE THE ECMWF HOLDS OFF. THE ECMWF IS SLOWER AND LESS AMPLIFIED
WITH A 300MB WEST TEXAS TROUGH WHILE THE GFS SHOWS AN
ANOMALOUSLY STRONG TROUGH WHICH GENERATES A WEST TEXAS SFC CYCLONE
THAT RIDES OVER A STALLED FRONT IN THE AREA PRODUCING WIDESPREAD
RAINFALL. THE ECMWF HOLDS UP BETTER RUN TO RUN AND GIVEN THE ANOMALOUS
STRENGTH OF THE 00Z GFS TROUGH WENT WITH THAT FOR THE FORECAST JUST
HOLDING A SLIGHT CHANCE OF SHOWERS IN THE FORECAST. A SHIFT THOUGH
TOWARDS A FINAL GFS SOLUTION WILL RESULT IN SIGNIFICANT INCREASES IN
RAIN CHANCES BY THE MIDDLE OF NEXT WEEK. /68-JGG/
MARINE...
TODAY THROUGH THURSDAY...BROAD HIGH PRESSURE OVER THE NORTH WEST
GULF WILL SUPPORT LIGHT TO MODERATE SOUTH SOUTHEAST WINDS THROUGH
THE SHORT TERM PERIOD. TWO TO FOUR FEET SEAS WILL PERSIST ON THE
GULF...WITH A LGT TO MODERATE CHOP ON THE BAY. AN ISOLATED MARINE
SHOWER MAY DEVELOP FROM TIME TO TIME.
THURSDAY NIGHT THROUGH MONDAY...
MODERATE EAST TO SOUTHEAST FLOW AND LOW TO MODERATE SEAS ARE
FORECAST THURSDAY NIGHT THROUGH MONDAY ALONG THE LOWER TEXAS COAST.
MORNING SHOWER AND THUNDERSTORM CHANCES WILL PERSIST THROUGH THE DAY
BUT WIDESPREAD SHOWERS AND THUNDERSTORMS ARE NOT CURRENTLY FORECAST.
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW EXERCISE CAUTION LEVELS
FOR THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 90 80 90 79 / 20 20 40 20
BROWNSVILLE 91 78 91 78 / 20 20 40 20
HARLINGEN 92 78 93 77 / 20 20 40 20
MCALLEN 94 78 94 78 / 10 10 30 20
RIO GRANDE CITY 94 77 95 78 / 10 10 20 20
SOUTH PADRE ISLAND 87 81 87 80 / 30 20 30 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
59...SHORT TERM
58...LONG TERM
CAMPBELL...GRAPHICS
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE
TROUGH MOVING SOUTHEAST OVER THE UPPER PENINSULA AND A STRONG COLD
FRONT DROPPING SOUTH OVER THE UPPER PENINSULA OF MICHIGAN.
SCATTERED SHOWERS OVER LAKE SUPERIOR ARE EXITING THE REGION AHEAD OF
THE SHORTWAVE. BUT THERE IS A FAIRLY WIDESPREAD AREA OF LOW STRATUS
BEHIND THE FRONT...THOUGH STARTING TO SEE SOME BREAKS IN THE
OVERCAST OCCUR OVER NORTHERN MINNESOTA AND LAKE SUPERIOR. NORTHEAST
WINDS ARE ALSO QUITE GUSTY RIGHT BEHIND THE FRONT COINCIDENT WITH
MODEST PRESSURE RISES...AND SOME GUSTS ARE REACHING 30 KTS OVER
SOUTHERN LAKE SUPERIOR. A CANADIAN SURFACE HIGH IS BUILDING
SOUTHEAST BEHIND THE FRONT AND USHERING IN ANOTHER COLD POLAR
AIRMASS WITH SOME SNOW BEING REPORTED JUST NORTH OF LAKE SUPERIOR.
AS THE FRONT DROPS SOUTH...SMALL PRECIP CHANCES...FROST/FREEZE
HEADLINES...AND WIND GUSTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE BACKDOOR COLD FRONT WILL CONTINUE TO SLIDE SOUTH
ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING
HOURS...BEFORE SETTLING OVER SOUTHERN WISCONSIN OVERNIGHT.
MID-LEVEL MOISTURE WILL BE EXITING WITH THE SHORTWAVE THIS
AFTERNOON...SO NOT ANTICIPATING ANY SHOWERS WITH THE FRONT. BUT DO
EXPECT A BAND OF LOW CLOUDS TO ACCOMPANY THE FRONT...ALONG WITH A
WIND SHIFT TO THE NORTHEAST. WITH THE WIND SHIFT...WINDS COULD
BECOME QUITE GUSTY OVER NORTHEAST WISCONSIN...AS TRAJECTORIES WILL
BE FAVORABLE FOR FUNNELING DOWN THE BAY OF GREEN BAY. SOME GUSTS TO
30 MPH ARE POSSIBLE. SOME LOW STRATUS WILL LIKELY LINGER OVER
CENTRAL AND EAST-CENTRAL WISCONSIN THROUGH THE NIGHT...BUT
SUBSIDENCE WILL LIKELY LEAD TO CLEARING OVER N-C WISCONSIN
OVERNIGHT. AS WINDS DIMINISH...THE LEADING GUIDANCE SHOWS LOW TEMPS
FALLING INTO THE UPPER 20S TO MID 30S OVER N-C WISCONSIN. WILL
HOIST A FROST ADVISORY FOR THAT REGION. GREATER CLOUD COVER AND
WIND SPEEDS SHOULD KEEP AREAS SAFE FROM THE FROST FURTHER SOUTH AND
EAST.
THURSDAY...PLENTY OF LOW LEVEL MOISTURE WILL LINGER BEHIND THE FRONT
OVER CENTRAL AND EAST-CENTRAL WISCONSIN IN THE MORNING...WHICH WILL
GRADUALLY RETURN NORTHWARD DURING THE AFTERNOON.
THEREFORE...ANTICIPATE SCT TO BKN CLOUDS TO EXPAND WITH HEATING OF
THE DAY. WITH THE CLOUD COVER AND SHALLOW COLD AIRMASS...HIGHS WILL
RANGE FROM THE MIDDLE 50S TO LOWER 60S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
ZONAL FLOW OVER THE NORTHERN CONUS LATE THIS WEEK WILL QUICKLY
TRANSITION TO MORE HIGHLY AMPLIFIED PATTERN...CHARACTERIZED BY DEEP
TROUGH OVER THE GREAT LAKES AND RIDGE OVER WESTERN CANADA...BY EARLY
NEXT WEEK. FORECAST CHALLENGE EARLY IN THE EXTENDED WILL BE CENTERED
AROUND TIMING AND INTENSITY OF INITIAL SHORTWAVE IMPULSES EMBEDDED
WITHIN ZONAL FLOW FRIDAY INTO SATURDAY. THEREAFTER GREAT LAKES
WILL BE DOMINATED NORTHWESTERLY UPPER-LEVEL FLOW AND BROAD HIGH
PRESSURE DURING THE FIRST HALF OF NEXT WEEK. BEST OPPORTUNITY FOR
SUBSTANTIAL RAINFALL WILL BE EARLY IN THE PERIOD FOLLOWED BY
MAINLY DRY CONDITIONS AT LEAST THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL START OUT ABOVE NORMAL FRIDAY AND SATURDAY...THEN
FALL BACK TO WELL BELOW NORMAL TOWARD THE MIDDLE PART OF NEXT
WEEK...WITH CHILLY NIGHTS AND POTENTIAL FOR AREAS OF FROST ACROSS
PARTS OF CENTRAL AND NORTHERN WISCONSIN.
INITIAL FORECAST CHALLENGE WILL BE TIMING OF SHOWER AND SCATTERED
THUNDERSTORMS ACTIVITY FRIDAY AFTERNOON AND EVENING WITH
APPROACHING SHORTWAVE IMPULSE...IN CONCERT WITH INCREASING LOW-
LEVEL WAA IN WAKE OF DEPARTING HIGH PRESSURE. WARM ADVECTION
BECOMES QUITE ROBUST BY 00Z SATURDAY AS 850 MB SOUTHWESTERLY WINDS
APPROACH 40 KTS. APPEARS MAJORITY OF LATEST MODEL GUIDANCE ARE A
BIT SLOWER ON INITIAL SHORTWAVE IMPULSE THUS HAVE TRIMMED BACK POPS
ACROSS THE EASTERN HALF OF THE FORECAST AREA IN THE 12Z TO 18Z
TIME FRAME FOR FRIDAY. APPEARS BEST FORCING WILL BE OVER NORTHERN
PORTION OF THE FORECAST AREA LATE FRIDAY AFTERNOON INTO FRIDAY
AND HAVE ADJUSTED POPS ACCORDINGLY. ON FRIDAY NIGHT...THE FORECAST
AREA SHOULD BE BECOME INCREASINGLY UNDER THE INFLUENCE OF THE RRQ
OF AN UPPER LEVEL JET THUS EXPECT GENERAL INCREASE IN ORGANIZED SCALE
SYNOPTIC SCALE LIFT AND DESTABILIZATION AHEAD OF SURFACE COLD
FRONT MOVING INTO CENTRAL MINNESOTA BY 06Z. ALTHOUGH STILL MODEL
DIFFERENCES IN LOCATION OF HEAVIEST QPF OVERNIGHT...ALL GUIDANCE
SUGGEST AN OVERALL INCREASE IN COVERAGE OF SHOWER AND THUNDERSTORM
ACTIVITY.
SATURDAY A BIT MORE UNCERTAIN AS STILL A FAIR AMOUNT OF MODEL
SPREAD ON TIMING OF COLD FRONT ACROSS THE FORECAST AREA. ECMWF
FASTER THAN MOST OF THE OTHER GUIDANCE. OPTED TO LEAN MORE TOWARD
A BLEND OF THE SREF MEAN AND ECMWF WHICH SUGGEST A SOMEWHAT FASTER
PROGRESSION. ADJUSTED POPS ACCORDINGLY WITH LIKELY POPS IN THE
MORNING AND TAPERED TOWARD CHANCE DURING THE AFTERNOON. GIVEN
THIS SCENARIO APPEARS ANY DEEP CONVECTION THAT CAN DEVELOP ALONG
THE COLD FRONT DURING THE AFTERNOON WILL MOST LIKELY OCCUR OVER
THE SOUTHEAST HALF OF THE STATE. IF ECMWF IS CORRECT...SATURDAY
AFTERNOON COULD BE MAINLY DRY. IF ENOUGH CLEARING CAN OCCUR
DAYTIME TEMPS SHOULD BE ABLE TO RESPOND AND RISE WELL INTO THE 70S
AS 850 TEMPS REALLY DO NOT FALL MUCH BEHIND THE COLD FRONT
INITIALLY.
ON SATURDAY NIGHT PRONOUNCED LFQ OF UPPER JET THEN PUSHES INTO
THE AREA WITH PRIMARY SHORTWAVE TROUGH CONTINUING TO DEEPEN OVER
THE AREA. WOULD EXPECT TO SEE SHOWER ACTIVITY INCREASE OVERNIGHT
SATURDAY ESPECIALLY ACROSS THE NORTH. UPPER TROUGH AXIS WILL
PERSIST OVER THE AREA ON SUNDAY WITH CAA CONTINUING. SCENARIO
FAVORABLE FOR AFTERNOON DIURNAL SHOWER ACTIVITY TO DEVELOP OVER
THE NORTHERN PORTION OF THE FORECAST AREA. LEFT SMALL POPS IN FOR
SUNDAY TO ACCOUNT FOR THIS.
HIGH PRESSURE FINALLY BUILDS IN SUNDAY NIGHT AND MONDAY BRINGING A
STRETCH OF DRIER WEATHER INTO AT LEAST MIDWEEK. EXPECT TEMPS TO BE
BELOW NORMAL THROUGH THE FIRST HALF OF THE WEEK WITH POTENTIAL FOR
SOME EARLY MORNING FROST OR FREEZE ESPECIALLY ON TUESDAY MORNING.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1133 AM CDT WED SEP 17 2014
A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE REGION
LATE THIS AFTERNOON AND EVENING. MOISTURE IS LACKING SO EXPECT ONLY
CLOUDS AS THE FRONT GOES BY. PLENTY OF MVFR CIGS BEHIND THE
FRONT...AND THINK THESE CIGS WILL MAKE IT INTO THE NORTH-CENTRAL AND
CENTRAL WISCONSIN TAF SITES. SOME CLEARING IS LIKELY ACROSS
NORTH-CENTRAL WISCONSIN LATE...WHICH WILL RESULT IN A FROST OR
FREEZE. SKIES WILL BECOME MOSTLY CLOUDY ONCE AGAIN THURSDAY
MORNING OVER N-C WISCONSIN WITH MVFR CIGS...BUT PARTLY SUNNY
FARTHER EAST.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 8 AM CDT THURSDAY FOR WIZ010>013-018-
019.
FREEZE WARNING FROM 1 AM TO 8 AM CDT THURSDAY FOR WIZ005.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......MPC