Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/16/14
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
920 PM MDT MON SEP 15 2014
.UPDATE...
ISSUED AT 920 PM MDT MON SEP 15 2014
IN THE SHORT TERM...MODELS HINT THAT MOISTURE FROM NEW MEXICO
RETURNS TO SOUTHWEST COLORADO LATE THIS EVENING. THIS IS NOT A
PRONOUNCED MOISTURE SURGE...BUT APPEARS THAT OUTFLOWS FROM SPOTTY
STORMS OVER NW NEW MEXICO (SSE GUSTY WIND AT FARMINGTON) GETS
INTO LA PLATA AND ARCHULETA COUNTIES. THE HRRR DEPICTS SPOTTY
LIGHT PCPN OVERNIGHT...SO ELECTED TO GO THE "ISOLATED" ROUTE
INSTEAD OF "SCATTERED". FOR THE REMAINDER OF THE FORECAST AREA...
LIMITED CONVECTIVE DEBRIS IS DISSIPATING FOR MOSTLY CLEAR
CONDITIONS.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 257 PM MDT MON SEP 15 2014
H5 HAND ANALYSIS AT 12Z HAD THE RIDGE AXIS ALONG THE GREAT BASIN TO
THE FAR WESTERN CANADIAN PROVINCES. THIS RIDGE IS SQUEEZED BETWEEN
AN EXPANSIVE EASTERN TROUGH EXTENDING FROM THE ARCTIC TO THE GREAT
LAKES...AND TROUGH OFF THE WEST COAST OF NOAM. LOWER DOWN A SURFACE
COLD FRONT WAS MAKING IT/S WAY DOWN THE SOUTHERN HIGH PLAINS...BUT
STALLING NEAR THE TX/OX/NM BORDERS LATE THIS AFTERNOON. UPPER JET
MAX HAS SHIFTING EAST AND WITH MINIMAL LARGE SCALE ASCENT OVER
OUR CWA...THE CONVECTION HAS FOCUSED OVER THE HIGHER TERRAIN WITH
PARTICULAR EMPHASIS ALONG THE TAVAPUTS/ROAN PLATEAU AND FLAT TOPS.
NEAR TERM MODELS SUGGEST THIS CONVECTION WILL REMAIN ISOLATED
THROUGH THE EVENING BEFORE DISSIPATING AFTER SUNSET. STRONG EML
SUGGEST WINDS THE BIGGEST THREAT. BOUNDARIES FROM STORMS MAY FORCE
A SHOWER INTO A VALLEY BUT CONFIDENCE FAIRLY LOW. BEST CHANCE FOR
THIS TO OCCUR WITH CURRENT 88D TRENDS IS THE SOUTHERN SAN JUAN
FOOTHILLS AND HAVE PUSHED POPS TO ISOLATED THERE AS WELL.
THE OVERALL PATTERN WILL BE SHIFTING SLIGHTLY OVER THE NEXT 36 TO 48
HOURS AS THE EASTERN TROUGH AXIS LIFTS NORTHEAST AND LOW PRESSURE
DEEPENS OFF THE WEST COAST. THIS WILL PUSH THE RIDGE AXIS ALONG THE
SPINE OF THE ROCKIES. THE RESULT WILL TEMPERATURES WARMING A FEW
DEGREES TOMORROW AND LIMITED CONVECTION AGAIN AS THE SUBSIDENCE
INVERSION SHOULD STRENGTHEN. ONE CHALLENGE WILL BE EARLY MORNING
CONVECTION OR A POSSIBLE PUSH OF LOW CLOUDS TOWARD THE SOUTHERN
VALLEYS. HIGH PRESSURE BUILDING DOWN THE LEE OF THE ROCKIES LOOKS TO
BULGE OVER THE LOWER DIVIDE IN NEW MEXICO WITH THE SOUTHERLY RETURN
FLOW POINTED TOWARD THE 4 CORNERS. AS A RESULT...DEW POINTS
SHOULD BE INCREASING THROUGH THE EARLY MORNING HOURS OVER
CEZ/DRO/PSO. ATTM MODELS SOUNDINGS AND RH FIELDS DO NOT SHOW
STRATUS BUILDING IN...BUT THIS MOISTURE MAY SERVE TO FUEL A BIT
MORE CONVECTION IN THE SOUTHERN SAN JUANS AS MOUNTAIN
CIRCULATIONS LIFT THE MOISTURE UP THE SLOPES TOMORROW AFTERNOON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 257 PM MDT MON SEP 15 2014
THE RIDGE AXIS IS STILL PROJECTED TO BE DIRECTLY OVER THE
FORECAST AREA AROUND NOON ON WEDNESDAY...CREATING A VERY WARM AND
PLEASANT DAY ACROSS THE REGION. A TRANSITION IN THE PATTERN WILL
BEGIN TO OCCUR THURSDAY ACROSS EASTERN UTAH AND THE FOUR CORNERS
REGION AS THE RIDGE SLIDES EAST AND GENERAL SOUTHWEST FLOW
DEVELOPS. PRECIPITABLE WATER VALUES CLIMB TO BETWEEN 0.75 INCHES
AND 1.0 INCHES THURSDAY NIGHT INTO FRIDAY ACROSS THE REGION. THE
REMNANTS OF HURRICANE ODILE ARE PROJECTED TO REACH THE NM/CO
BORDER LATE THURSDAY NIGHT BUT OTHERWISE STAY TO THE SOUTH AND
EAST OF THE FORECAST AREA.
THE DETAILS ON ACTUAL DYNAMIC FORCING MECHANISMS NEAR THE END OF
THE WEEK ARE STILL VERY FUZZY WITH FORECAST MODELS SWITCHING
SOLUTIONS ALMOST EVERY CONSECUTIVE RUN. EXPECT AN UPTICK IN
ACTIVITY AT THE END OF THE WEEK AND INTO THE WEEKEND...BUT VERY
LOW CONFIDENCE ON TIMING AND EXACT THREAT AT THIS TIME. THE LATEST
MODELS SUGGEST A BREAK IN ACTIVITY ON SATURDAY...BUT WITH
MOISTURE STILL IN PLACE THINKING THAT THIS COULD REALLY FUEL
DIURNAL ACTIVITY ON SATURDAY WITH THE ADDED BENEFIT OF BREAKS IN
THE CLOUDS. AT THIS TIME...SUNDAY AND MONDAY LOOK TO BE RELATIVELY
ACTIVE WITH DIURNAL ACTIVITY AS A TROUGH PASSES THROUGH THE GREAT
BASIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 626 PM MDT MON SEP 15 2014
LATEST TRENDS PER SATELLITE AND RADAR IMAGES INDICATE ANY
THUNDERSTORM POTENTIAL IS ENDING OVER WRN COLORADO. ELSEWHERE...
NO OTHER WEATHER IS EXPECTED THROUGH 18Z TUESDAY AFTERNOON.
AFTER 18Z...ISOLATED -TSRA/-SHRA IS EXPECTED OVER THE SRN
MOUNTAINS AND COULD BE IN THE VICINITY OF KTEX AND KDRO.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...15
LONG TERM...JAM
AVIATION...PF
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
849 PM MDT MON SEP 15 2014
.UPDATE...
ISSUED AT 837 PM MDT MON SEP 15 2014
THE ISOLATED SHOWERS/STORMS HAVE DISSIPATED FOR THE NIGHT AND HAVE
REMOVED FROM EVENING FORECAST. ONLY MINOR ADJUSTMENTS TO SKY
COVER/FOG OVERNIGHT OVER THE PLAINS. STATUS ALREADY COVERS MUCH OF
SOUTHEAST COLORADO AND JUST INCHING INTO LINCOLN COUNTY EARLY THIS
EVENING. SHORT RANGE MODELS HINT AT A BIT OF THE STRATUS FOG
WRAPPING UP FURTHER NORTH AND WEST OVER WELD AND MORGAN COUNTIES
SO THERE MAY ALSO BE SOME PATCHY FOG OVER THE SOUTH PLATTE RIVER
VALLEY TOWARDS DAYBREAK.
UPDATE ISSUED AT 610 PM MDT MON SEP 15 2014
UPDATED FORECAST FOR PATCHY FOG AFTER MIDNIGHT MAINLY OVER
LINCOLN COUNTY. STRATUS ALREADY IN FORECAST...CURRENT AREA OF
STRATUS OVER SOUTHEAST COLORADO IS EXPECTED TO BE PUSHED BACK IN
WITH SOUTHEASTERLY WINDS. HRRR AND RAP SHORT TERM MODELS BOTH
HINTING OF FOG DEVELOPING AROUND OR AFTER MIDNIGHT. SOUTHEASTERLY
WINDS OF 10 TO 15 MPH WITH GUSTS TO 25 MPH MAY LIMIT THE AMOUNT OF
FOG TO DEVELOP...BUT STILL HAVE HIGH HUMIDITY EXPECTED...SO KEPT
THE COVERAGE TO PATCHY INSTEAD OF AREAS OF OR WIDESPREAD FOG.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 205 PM MDT MON SEP 15 2014
PRESSURE FALLS ACROSS EASTERN WYOMING WILL SPREAD INTO EASTERN
COLORADO MONDAY AFTERNOON AND SURFACE WINDS BY EVENING WILL
BECOME MORE SOUTH-SOUTHEASTERLY OVER THE PLAINS IN RESPONSE. WILL
PROBABLY SEE A DENVER CYCLONE SET UP BY LATE AFTERNOON. CONVECTION
IS FORMING IN THE MOUNTAINS BUT ATMOSPHERE ON THE PLAINS IS MORE
STABLE AND MOISTURE IS LIMITED. THEREFORE EXPECT THUNDERSTORMS TO
REMAIN IN AND NEAR THE MOUNTAINS. STORMS WILL HAVE LIMITED
COVERAGE OF RAINFALL BUT MAY PRODUCE BRIEF GUSTY WINDS.
CHANCE FOR AFTERNOON CONVECTION IS EVEN LESS ON TUESDAY AS LARGE
RIDGE BUILDS OVER THE REGION. PW VALUES AND SFC DEWPOINTS WILL
LIKELY BE A LITTLE LOWER TUESDAY THAN TODAY. AFTERNOON CU NEAR
THE MOUNTAINS AND THE POSSIBILITY OF A FEW CIRRUS MAY DECREASE
SOLAR INPUT A LITTLE BUT EXPECT ABOVE AVERAGE TEMPS REACHING THE
MID 80S IN MANY LOWER ELEVATION AREAS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 205 PM MDT MON SEP 15 2014
AN UPPER LEVEL RIDGE OVER THE SW PORTIONS OF THE US WILL BE OVER
CO ON WED AND REMAIN IN PLACE THROUGH THURSDAY MORNING BEFORE IT
MOVES EAST. THERE IS ADEQUATE MID LEVEL MOISTURE TUESDAY EVENING
INTO WEDNESDAY MORNING FOR A POSSIBLE WAVE CLOUD SET-UP OVER THE
FRONT RANGE THAT WILL ADVECT EAST THROUGH THE AFTERNOON AND
DISSIPATE. SOME LIGHT MOISTURE WILL HANG IN THE MOUNTAINS SO WILL
KEEP A SLIGHT CHANCE OF THUNDERSTORMS OVER THE HIGHER MOUNTAINS
FOR WEDNESDAY AFTERNOON. CONDITIONS WILL BE STABLE OVER THE
FOOTHILLS AND URBAN CORRIDOR..WHICH WILL HINDER ANY THUNDERSTORM
DEVELOPMENT. MODELS ARE SHOWING A WEAK SFC LOW DIPPING INTO THE
FAR NE PORTIONS OF THE STATE BRINGING IN SOME LL MOISTURE BUT
SOUNDINGS ARE CAPPED SO LITTLE DEVELOPMENT WILL TAKE PLACE. TEMPERATURES
WILL CONTINUE TO INCREASE WED AND THU OVER NE COLORADO AS RIDGING
COMBINED WITH DOWNSLOPE FLOW WILL AID IN STABILIZING AND HEATING.
LOOK FOR TEMPERATURES TO BE IN THE MID 80S WITH LOWER 80S OUT ON
THE PLAINS.
BY THU AFTERNOON THE UPPER LEVEL RIDGE WILL HAVE STARTED TO MOVE
EAST WITH FLOW TURNING MORE SOUTHERLY AS THE REMNANTS OF
HURRICANE ODILE MOVES IN FROM THE SW. CONDITIONS WILL REMAIN DRY
THURSDAY AS THE TROPICAL MOISTURE IS STILL EMBEDDED IN THE FLOW TO
THE SOUTH. WILL KEEP A SLIGHT CHANCE IN THE MOUNTAINS WITH TEMPS
INCREASING INTO THE LOWER 90S FOR THE PLAINS. THE MODELS HAVE
DIVERGED A BIT WITH THE MOISTURE ADVECTION AND FRONT PROGGED TO
MOVE IN FRIDAY. BOTH THE GFS AND THE EC MOVE THE TROPICAL
MOISTURE FROM ODILE NNE INTO THE SOUTHERN PORTIONS OF THE STATE BY
12Z FRIDAY. THE GFS HOWEVER HAS INCREASED AND DEEPENED THE
MOISTURE FROM THIS SYSTEM UNLIKE THE EC WHICH KEEPS IT MORE IN THE
UPPER LEVELS WITH DRIER CONDITIONS NEAR THE SURFACE OVER THE
PLAINS. AT THIS TIME IT STILL LOOKS LIKE THE BEST CHANCE FOR
PRECIP WILL BE IN THE MOUNTAINS WITH A SLIGHT CHANCE OVER THE
PLAINS. TEMPERATURES WILL BE IN THE MID 80S BUT TIMING WILL
DEPEND ON WHEN THE FRONT MOVES THROUGH.
FLOW WILL TURN NORTHWEST ON SATURDAY AS SURFACE HIGH PRESSURE
BUILDS BACK IN TO THE REGION. THERE WILL BE LINGERING MOISTURE
OVER THE MOUNTAINS SO WILL PUT IN A SLIGHT CHANCE OF STORMS FOR
SATURDAY AFTERNOON WITH THE PLAINS REMAINING DRY. HIGHS WILL DROP
BACK INTO THE LOWER TO MID 70S SAT. ON SUNDAY MOISTURE FROM A
SYSTEM MOVING OVER SOUTHERN CA WILL ADVECT INTO THE SW PORTIONS OF
THE STATE SO WILL KEEP A SLIGHT CHANCE OF TS OVER THE MOUNTAINS
FOR SUNDAY AS WELL WITH TEMPERATURES CONTINUING TO REBOUND BACK
INTO THE MID 70S TO LOWER 80S.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 837 PM MDT MON SEP 15 2014
SURFACE CYCLONE IN THE VCNTY OF KDEN WITH SOUTHERLY WINDS EAST AND
SOUTH OF DENVER AND MORE NORTHWEST WEST OF DIA AND TOWARDS BJC.
SURFACE TROF SHIFTS EAST OVERNIGHT WITH MORE WIDESPREAD SOUTHWEST
WINDS OVER TERMINALS. THE HRR HINTS AT POSSIBLE FOG AT DEN LATER
TNT BUT WILL KEEP OUT OF FORECAST FOR NOW. OTHERWISE MOSTLY CLEAR
SKIES TNT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ENTREKIN
SHORT TERM...GIMMESTAD/KELSCH
LONG TERM...RPK
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
615 PM MDT MON SEP 15 2014
.UPDATE...
ISSUED AT 610 PM MDT MON SEP 15 2014
UPDATED FORECAST FOR PATCHY FOG AFTER MIDNIGHT MAINLY OVER
LINCOLN COUNTY. STRATUS ALREADY IN FORECAST...CURRENT AREA OF
STRATUS OVER SOUTHEAST COLORADO IS EXPECTED TO BE PUSHED BACK IN
WITH SOUTHEASTERLY WINDS. HRRR AND RAP SHORT TERM MODELS BOTH
HINTING OF FOG DEVELOPING AROUND OR AFTER MIDNIGHT. SOUTHEASTERLY
WINDS OF 10 TO 15 MPH WITH GUSTS TO 25 MPH MAY LIMIT THE AMOUNT OF
FOG TO DEVELOP...BUT STILL HAVE HIGH HUMIDITY EXPECTED...SO KEPT
THE COVERAGE TO PATCHY INSTEAD OF AREAS OF OR WIDESPREAD FOG.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 205 PM MDT MON SEP 15 2014
PRESSURE FALLS ACROSS EASTERN WYOMING WILL SPREAD INTO EASTERN
COLORADO MONDAY AFTERNOON AND SURFACE WINDS BY EVENING WILL
BECOME MORE SOUTH-SOUTHEASTERLY OVER THE PLAINS IN RESPONSE. WILL
PROBABLY SEE A DENVER CYCLONE SET UP BY LATE AFTERNOON. CONVECTION
IS FORMING IN THE MOUNTAINS BUT ATMOSPHERE ON THE PLAINS IS MORE
STABLE AND MOISTURE IS LIMITED. THEREFORE EXPECT THUNDERSTORMS TO
REMAIN IN AND NEAR THE MOUNTAINS. STORMS WILL HAVE LIMITED
COVERAGE OF RAINFALL BUT MAY PRODUCE BRIEF GUSTY WINDS.
CHANCE FOR AFTERNOON CONVECTION IS EVEN LESS ON TUESDAY AS LARGE
RIDGE BUILDS OVER THE REGION. PW VALUES AND SFC DEWPOINTS WILL
LIKELY BE A LITTLE LOWER TUESDAY THAN TODAY. AFTERNOON CU NEAR
THE MOUNTAINS AND THE POSSIBILITY OF A FEW CIRRUS MAY DECREASE
SOLAR INPUT A LITTLE BUT EXPECT ABOVE AVERAGE TEMPS REACHING THE
MID 80S IN MANY LOWER ELEVATION AREAS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 205 PM MDT MON SEP 15 2014
AN UPPER LEVEL RIDGE OVER THE SW PORTIONS OF THE US WILL BE OVER
CO ON WED AND REMAIN IN PLACE THROUGH THURSDAY MORNING BEFORE IT
MOVES EAST. THERE IS ADEQUATE MID LEVEL MOISTURE TUESDAY EVENING
INTO WEDNESDAY MORNING FOR A POSSIBLE WAVE CLOUD SET-UP OVER THE
FRONT RANGE THAT WILL ADVECT EAST THROUGH THE AFTERNOON AND
DISSIPATE. SOME LIGHT MOISTURE WILL HANG IN THE MOUNTAINS SO WILL
KEEP A SLIGHT CHANCE OF THUNDERSTORMS OVER THE HIGHER MOUNTAINS
FOR WEDNESDAY AFTERNOON. CONDITIONS WILL BE STABLE OVER THE
FOOTHILLS AND URBAN CORRIDOR..WHICH WILL HINDER ANY THUNDERSTORM
DEVELOPMENT. MODELS ARE SHOWING A WEAK SFC LOW DIPPING INTO THE
FAR NE PORTIONS OF THE STATE BRINGING IN SOME LL MOISTURE BUT
SOUNDINGS ARE CAPPED SO LITTLE DEVELOPMENT WILL TAKE PLACE. TEMPERATURES
WILL CONTINUE TO INCREASE WED AND THU OVER NE COLORADO AS RIDGING
COMBINED WITH DOWNSLOPE FLOW WILL AID IN STABILIZING AND HEATING.
LOOK FOR TEMPERATURES TO BE IN THE MID 80S WITH LOWER 80S OUT ON
THE PLAINS.
BY THU AFTERNOON THE UPPER LEVEL RIDGE WILL HAVE STARTED TO MOVE
EAST WITH FLOW TURNING MORE SOUTHERLY AS THE REMNANTS OF
HURRICANE ODILE MOVES IN FROM THE SW. CONDITIONS WILL REMAIN DRY
THURSDAY AS THE TROPICAL MOISTURE IS STILL EMBEDDED IN THE FLOW TO
THE SOUTH. WILL KEEP A SLIGHT CHANCE IN THE MOUNTAINS WITH TEMPS
INCREASING INTO THE LOWER 90S FOR THE PLAINS. THE MODELS HAVE
DIVERGED A BIT WITH THE MOISTURE ADVECTION AND FRONT PROGGED TO
MOVE IN FRIDAY. BOTH THE GFS AND THE EC MOVE THE TROPICAL
MOISTURE FROM ODILE NNE INTO THE SOUTHERN PORTIONS OF THE STATE BY
12Z FRIDAY. THE GFS HOWEVER HAS INCREASED AND DEEPENED THE
MOISTURE FROM THIS SYSTEM UNLIKE THE EC WHICH KEEPS IT MORE IN THE
UPPER LEVELS WITH DRIER CONDITIONS NEAR THE SURFACE OVER THE
PLAINS. AT THIS TIME IT STILL LOOKS LIKE THE BEST CHANCE FOR
PRECIP WILL BE IN THE MOUNTAINS WITH A SLIGHT CHANCE OVER THE
PLAINS. TEMPERATURES WILL BE IN THE MID 80S BUT TIMING WILL
DEPEND ON WHEN THE FRONT MOVES THROUGH.
FLOW WILL TURN NORTHWEST ON SATURDAY AS SURFACE HIGH PRESSURE
BUILDS BACK IN TO THE REGION. THERE WILL BE LINGERING MOISTURE
OVER THE MOUNTAINS SO WILL PUT IN A SLIGHT CHANCE OF STORMS FOR
SATURDAY AFTERNOON WITH THE PLAINS REMAINING DRY. HIGHS WILL DROP
BACK INTO THE LOWER TO MID 70S SAT. ON SUNDAY MOISTURE FROM A
SYSTEM MOVING OVER SOUTHERN CA WILL ADVECT INTO THE SW PORTIONS OF
THE STATE SO WILL KEEP A SLIGHT CHANCE OF TS OVER THE MOUNTAINS
FOR SUNDAY AS WELL WITH TEMPERATURES CONTINUING TO REBOUND BACK
INTO THE MID 70S TO LOWER 80S.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z TUESDAY LATE AFTERNOON)
ISSUED AT 205 PM MDT MON SEP 15 2014
THUNDERSTORM ACTIVITY ON MONDAY EVENING WILL LIKELY STAY IN AND
NEAR THE MOUNTAINS, AND LITTLE OR NO THUNDERSTORM ACTIVITY IS
EXPECTED TUESDAY. STRATUS AND FOG DEVELOPMENT IN THE PREDAWN HOURS
ON TUESDAY SHOULD BE LESS EXTENSIVE THAN THE CLOUDS ON MONDAY
MORNING AND THE DENVER AREA AIRPORTS ARE NOT EXPECTED TO SEE LOW
CLOUDS. A WINDSHIFT TO THE NORTH IS EXPECTED BY LATE TUESDAY
MORNING AND THEN THE WINDS ON TUESDAY AFTERNOON ARE EXPECTED TO
BECOME LIGHT AND FOLLOW THE DIURNAL PATTERN OF SWITCHING AROUND
TO THE EAST AND THEN SOUTHEAST.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KRIEDERMAN
SHORT TERM...GIMMESTAD/KELSCH
LONG TERM...RPK
AVIATION...GIMMESTAD/KELSCH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
958 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/...
10 PM UPDATE...
NO MAJOR ADJUSTMENTS WITH THIS UPDATE EITHER. PRIMARY CHANGES
WERE TO INCREASE CLOUD COVER ACROSS THE AREA AS HIGH CLOUDS ARE
ALREADY SPILLING INTO THE REGION FROM THE W. WITH THIS IN MIND
ALSO...HAVE INCREASED BOTH HOURLY AND MIN TEMPS AS WELL AS DWPTS
A BIT WITH THIS UPDATE. THE INCREASED CLOUD COVER AND SLIGHT UP-
TICK IN DWPTS IS LIKELY TO MITIGATE COOLING TONIGHT IN COMPARISON TO
PREVIOUS COOLER NIGHTS. OTHERWISE...FORECAST ON TRACK...INCLUDING
POPS TOWARD DAYBREAK.
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 /02Z TUESDAY 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.
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.
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...DOODY/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...RLG
AVIATION...RLG/SIPPRELL
MARINE...RLG/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
709 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/...
715 PM UPDATE...MADE A FEW MINOR EDITS TO THE FORECAST BASED ON
LATEST TRENDS. OTHERWISE THE FORECAST IS ON TRACK. A FEW MID LEVEL
CLOUDS ARE HANGING AROUND SOUTHEASTERN MASS OTHERWISE...MOSTLY
CLEAR SKIES FOR THE TIME BEING.
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 /23Z 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.
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.
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...RLG/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...RLG
AVIATION...RLG/SIPPRELL
MARINE...RLG/SIPPRELL
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
1135 AM EDT SUN SEP 14 2014
.UPDATE...
A SLIVER OF DRIER AIR HAS MOVED THROUGH THE AREA THIS MORNING ON
THE EDGE OF AN UPPER LEVEL JET SETTLING SOUTH ACROSS THE
PENINSULA. THE JET SHOULD SLIP SOUTH ACROSS A FORT MYERS TO FORT
PIERCE LINE...PUSHING THE DRIER AIR SOUTH INTO THE FLORIDA
STRAITS. THIS SHOULD ALLOW MOISTURE TO RETURN OVER WEST CENTRAL
AND SOUTHWEST FLORIDA LATER TODAY WHICH WILL COMBINE WITH A GULF
COAST SEA BREEZE AND DIURNAL HEATING TO PRODUCE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING.
AN OUTFLOW FROM EARLIER CONVECTION NEAR THE KEYS HAS MADE ITS WAY
INTO THE WATERS OFF SOUTHWEST FLORIDA AND WILL SOON COME ASHORE.
HAVE ADJUSTED POPS OFF THE OBSERVED TRENDS ALONG WITH NEW HRRR AND
LOCAL CAM GUIDANCE RUNS. UPDATED ZONES HAVE ALREADY BEEN
SENT...EXPECT A LATE START TO DIURNAL CONVECTION AGAIN TODAY WITH
ACTIVITY FORMING INLAND AND ALONG THE SEA BREEZE AS IT PUSHES IN
ALONG THE INTERSTATE 75 CORRIDOR. THE SOUTHEASTERLY FLOW WILL THEN
PUSH THE CONVECTION TO THE NORTHWEST. THE FLOW SHOULD PROMOTE
QUICK STORM MOVEMENT...THOUGH SOME AREAS COULD SEE NUISANCE
FLOODING FROM SEVERAL STORMS AND TRAINING OF STORMS OVER THE SAME
AREA. GUSTY WINDS AND LIGHTNING ARE THE PRIMARY CONCERNS WITH
CONVECTION TODAY. AFTER SUNSET...THE REMAINING ACTIVITY SHOULD
PUSH OFFSHORE AND DIMINISH OVER LAND.
&&
.AVIATION...
VFR EXPECTED THROUGH THE PERIOD...THOUGH BRIEF MVFR/IFR POSSIBLE
WITH STORMS TODAY. SOUTHEAST FLOW AROUND 10 KNOTS TODAY...WITH
GUSTY VARIABILITY AROUND CONVECTION. TIMING OF CONVECTION START THIS
AFTERNOON FROM AROUND 17Z-18Z IN SW FLORIDA TO 20-21Z AROUND THE
TAMPA BAY AREA TERMINALS. CONVECTION SHOULD DIMINISH FROM SOUTH TO
NORTH SIMILARLY...BETWEEN 00Z TO 04Z.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE NORTH OF THE WATERS TODAY WILL BEGIN TO
WEAKEN AND SLIP SOUTH INTO THE COASTAL WATERS MONDAY AND TUESDAY. A
WEAK COLD FRONT WILL APPROACH THE NORTHEAST GULF TUESDAY NIGHT THEN
MOVE VERY SLOWLY SOUTHWARD THROUGH THE WATERS WEDNESDAY AND
THURSDAY. SEAS MAY BE AS HIGH AS 3 FEET WELL OFFSHORE EARLY
TODAY...BUT THE OVERALL TREND WILL BE FOR DECREASING WINDS AND SEAS
OVER THE NEXT COUPLE OF DAYS AS THE RIDGE SETTLES IN OVER FLORIDA.
AFTER THAT...SOME WESTERLY FLOW WILL DEVELOP AHEAD OF THE WEAK
FRONTAL BOUNDARY TOWARD THE MIDDLE OF THE WEEK...BUT AT THIS TIME WE
DO NOT EXPECT WINDS AND SEAS TO INCREASE SIGNIFICANTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 91 76 91 77 / 60 40 40 30
FMY 91 73 92 75 / 70 30 60 30
GIF 92 74 92 74 / 50 40 50 30
SRQ 91 74 91 76 / 60 40 40 30
BKV 92 71 92 71 / 50 40 50 40
SPG 90 78 90 79 / 60 40 40 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...02/GARCIA
MARINE...63/JILLSON
DECISION SUPPORT...57/MCMICHAEL
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 AM EDT SUN SEP 14 2014
.DISCUSSION...
.UPDATE...10Z CAPE SOUNDING INDICATED PRECIPITABLE WATER VALUES NEAR
1.8 INCHES WITH LOW LVL S/SE FLOW BACKING TO THE E/ENE ABOVE 700 MBS
WITH 40-45 KNOTS OF NE UPPER LEVEL WINDS ABOVE 300 MBS. GPS PRECIP
WATER VALUES HAVE BEEN TRENDING DOWN THIS MORNING WITH READING OF
1.67 AT THE CAPE AT 1145Z...1.65 AT OKEECHOBEE...1.45 AT BARTOW AND
1.48 INCHES IN GAINESVILLE. MODELS INDICATE ADDITIONAL DRYING IN THE
H7-H5 LAYER AND ALSO ALOFT FROM THE E AND NE WHICH SHOULD ACT TO
LIMIT COVERAGE OF SHOWER AND THUNDERSTORMS. 10 AM SFC DWPTS RANGED
FROM 68 DEGS AT KFPR AND KSUA TO THE LOWER 70S ACROSS NRN AREAS.
WATER VAPOR IMAGERY SHOWS SOME VERY DRY AIR ALOFT ACROSS MARTIN
COUNTY AND THE LAKE OKEECHOBEE REGION WITH SOME LARGE SCALE
SUBSIDENCE LIKELY ALONG THE NOSE OF AN 250 MB JET STREAK. THE SHORT
RANGE MESOSCALE RUNS FROM THE HRRR ARE ALSO NOT THAT ROBUST WITH
CONVECTION SHOWING MAINLY SHOWERS DEVELOPING OVER THE INTERIOR THIS
AFTERNOON AND MOVING WESTWARD INTO THE LATE AFTERNOON AND EARLY
EVENING. WILL BE ABLE TO LOWER POPS ALONG THE COAST IN THIS REGIME
TO AROUND 20 PCT AND WILL PROBABLY CONTINUE WITH 30-40 PCT RAIN
CHANCES FOR INTERIOR AREAS. HIGHS EXPECTED IN THE UPPER 80S COAST TO
AROUND 90 TO THE LOWER 90S ACROSS THE INTERIOR.
&&
.AVIATION...SHOULD SEE ISOLD-SCT SHRA/TSRA DVLP ACROSS INTERIOR
AREAS THIS AFTERNOON AND MOVE WESTWARD. CHCS DO NOT LOOK HIGH ENOUGH
TO HAVE MORE THAN VC IN TERMINALS AT THIS TIME.
&&
.MARINE...
SE WINDS 5 TO 10 KNOTS WITH SEAS AROUND 2 FT ACROSS THE WATERS WITH
ONLY ISOLATED SHOWERS/THUNDERSTORMS AT BEST. FORECAST ON TRACK.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
VOLKMER/SEDLOCK
AREA FORECAST DISCUSSION
NWS MIAMI FL
756 AM EDT SUN SEP 14 2014
.AVIATION...
EASTERLY FLOW CONTINUES TODAY, HOWEVER RELATIVELY MID LEVEL DRIER
AIR ARRIVING THIS AFTERNOON, AS SEEN ON CURRENT WATER VAPOR IMAGES
SHOULD KEEP PRECIP CHANCES LOW AND THUNDERSTORMS WIDELY SCATTERED
KTMB/KOPF/KMIA. AGAIN, EXPECTING BEST COVERAGE OF SHOWERS AND
STORMS TO BE ACROSS INLAND SECTIONS AND WEST COAST. GUIDANCE HAS
BACKED OFF A BIT WITH REGARDS TO A GULF BREEZE DEVELOPING AT KAPF
THIS PM, BUT STORMS PROGRESSING ACROSS THE PENINSULA SHOULD
EVENTUALLY AFFECT THAT TERMINAL. SOME MVFR/IFR CONDS POSSIBLE
WITH TEMPO GROUPS NECESSARY THIS PM AT KAPF. ELSEWHERE, CAN`T
RULE OUT SOME SHOWERS MAINLY THIS MORNING DEVELOPING ALONG THE
IMMEDIATE EAST COAST, OR ARRIVING FROM OFFSHORE BUT WILL NOT BE
INCLUDING ANY VCTS AT THIS TIME FOR AFTERNOON STORMS, AS MOST EAST
COAST TERMINALS SHOULD BE BEHIND THE SEA BREEZE BOUNDARY. ENOUGH
MID LEVEL DRIER AIR MAY REMAIN TONIGHT TO BREAK THE STRING OF WET
AND STORMY OVERNIGHTS.
&&
.PREV DISCUSSION... /ISSUED 402 AM EDT SUN SEP 14 2014/
SHORT TERM...(TODAY-TUESDAY)
THE EARLY MORNING SURFACE ANALYSIS SHOWED SOUTHEAST FLOW ACROSS THE
LOCAL AREA WITH A WEAK FRONTAL BOUNDARY EXTENDING SW ACROSS THE
REGION TO THE NORTH AND A WEAK TROUGH OF LOW PRESSURE CENTERED OVER
THE CENTRAL GULF OF MEXICO. THE LATEST WATER VAPOR LOOP SHOWED A
COMPLEX MID/UPPER LEVEL PATTERN ACROSS THE REGION CHARACTERIZED WITH
A RIDGE AXIS ORIENTED FROM EAST TO WEST OVER THE NORTHERN GULF COAST
STATES AND TWO UPPER LOWS EAST AND WEST OF THE FLORIDA PENINSULA.
PLENTY OF MID-UPPER MOISTURE CONTINUES TO LIFT NORTH OVER THE AREA
EAST OF THE UPPER LOW OVER THE GULF OF MEXICO...WHICH SUPPORTS THE
WIDESPREAD SHOWER ACTIVITY OVER THE ATLANTIC AND EAST COAST
LOCATIONS THIS MORNING. THE LATEST HRRR MODEL RUN HAS INITIALIZED
WELL WITH THIS ACTIVITY AND GENERALLY INDICATES A LARGE SHIELD OF
MAINLY LIGHT TO MODERATE RAIN REMAINING POSSIBLE THROUGH THE MID-
MORNING HOURS BEFORE DIMINISHING. LATER THIS AFTERNOON THE LATEST
MODEL SOUNDINGS INDICATE SOME DRIER AIR FILLING IN FROM THE
SOUTHEAST WITH PWATS DROPPING TOWARD 1.6" OVER THE SE FLORIDA
COAST AND INCREASING TO OVER THE 2" MARK BETWEEN NAPLES AND THE
LAKE LATER TODAY. THIS GRADIENT WILL BE REFLECTED IN THE LATEST
FORECAST PACKAGE SHOWING THE GREATEST RAINFALL CHANCES ALONG THE
SOUTHEAST FLORIDA COAST THROUGH THE MORNING HOURS AND ACROSS THE
INTERIOR AND LAKE REGION LATER THIS AFTERNOON THROUGH THIS
EVENING. MONDAY THROUGH TUESDAY...CONDITIONS ARE EXPECTED TO TREND
BACK TOWARD NORMAL AS SOME ADDITIONAL MID-LEVEL DRY AIR MOVES INTO
THE AREA. EASTERLY LOW-LEVEL FLOW UP TO 700 MB WILL PERSIST
THROUGH THIS TIME...WHICH WILL KEEP THE DIURNALLY DRIVEN
CONVECTIVE ACTIVITY FOCUSED INLAND AND TOWARD THE GULF COAST EACH
AFTERNOON/EVENING.
/85
LONG TERM (WEDNESDAY-FRIDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT AND
GENERALLY INDICATES FALLING UPPER HEIGHTS IN RESPONSE TO A DEEPENING
UPPER TROUGH ACROSS THE REGION. A FRONTAL BOUNDARY IS PROJECTED TO
SHIFT SOUTHWARD TOWARD AND POSSIBLY INTO THE LOCAL AREA BEFORE
STALLING. THE GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT IN THIS
00Z CYCLE REGARDING THE SOUTHWARD PROGRESSION OF THIS BOUNDARY
MOVING INTO THE AREA BY THURSDAY DUE TO A SHORTWAVE WRAPPING AROUND
THE BASE OF THE UPPER TROUGH NORTH OF THE AREA AND SFC WAVE
DEVELOPING ALONG THE BOUNDARY OFF OF THE GA/SC COAST BY THURSDAY.
THIS SHOULD TRANSLATE TO A WET PATTERN FOR SOUTH FLORIDA WITH SW LOW-
LEVEL FLOW AHEAD OF THE BOUNDARY AND PLENTY OF DEEP LAYER MOISTURE.
THE HIGHEST RAINFALL PROBABILITIES ARE PROJECTED TO SET UP AND
FOCUSING ALONG THE EAST COAST AREAS EACH AFTERNOON GOING INTO THE
WEEKEND EACH DAY.
/85
AVIATION...
SHOWERS AND STORMS WERE ONGOING ACROSS THE ATLANTIC WATERS...AND
ISOLATED SHOWERS WERE MOVING BACK INTO THE EAST COAST NEAR KFLL.
SHOWERS MAY MOVE BACK INTO THE EAST COAST OVERNIGHT AND THEN TAPER
OFF IN THE MORNING. BRIEF MVFR/IFR CONDITIONS ARE POSSIBLE. GUIDANCE
IS INDICATING DRIER AIR MAY BEGIN MOVING INTO THE EASTERN PORTIONS
OF THE REGION IN THE AFTERNOON. SO REMOVED VCTS FOR THE EAST COAST
METRO AREAS FOR THE AFTERNOON HOURS. LIGHT WINDS EARLY THIS MORNING
WILL BECOME SOUTHEAST AROUND 10 KNOTS IN THE AFTERNOON...AND THEN
DIMINISH AGAIN IN THE EVENING. FOR KAPF...A WEAK GULF COAST SEA
BREEZE MAY DEVELOP IN THE AFTERNOON. THE BEST CHANCE OF STORMS NEAR
KAPF IS ALSO FORECAST TO BE IN THE AFTERNOON.
/84
MARINE...
AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE
MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO
MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY
HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL
BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING
WEEK WITH SOUTHEAST WINDS CONTINUING. A COLD FRONT WILL APPROACH
FROM THE NORTH AND MAY LEAD TO SOUTH AND SOUTHWEST WINDS BY THE END
OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 77 87 77 / 40 20 40 20
FORT LAUDERDALE 87 79 88 79 / 30 20 30 20
MIAMI 87 78 88 78 / 20 20 30 20
NAPLES 88 75 90 76 / 70 20 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...85/AG
LONG TERM....85/AG
AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
402 AM EDT SUN SEP 14 2014
.SHORT TERM...(TODAY-TUESDAY)
THE EARLY MORNING SURFACE ANALYSIS SHOWED SOUTHEAST FLOW ACROSS THE
LOCAL AREA WITH A WEAK FRONTAL BOUNDARY EXTENDING SW ACROSS THE
REGION TO THE NORTH AND A WEAK TROUGH OF LOW PRESSURE CENTERED OVER
THE CENTRAL GULF OF MEXICO. THE LATEST WATER VAPOR LOOP SHOWED A
COMPLEX MID/UPPER LEVEL PATTERN ACROSS THE REGION CHARACTERIZED WITH
A RIDGE AXIS ORIENTED FROM EAST TO WEST OVER THE NORTHERN GULF COAST
STATES AND TWO UPPER LOWS EAST AND WEST OF THE FLORIDA PENINSULA.
PLENTY OF MID-UPPER MOISTURE CONTINUES TO LIFT NORTH OVER THE AREA
EAST OF THE UPPER LOW OVER THE GULF OF MEXICO...WHICH SUPPORTS THE
WIDESPREAD SHOWER ACTIVITY OVER THE ATLANTIC AND EAST COAST
LOCATIONS THIS MORNING. THE LATEST HRRR MODEL RUN HAS INITIALIZED
WELL WITH THIS ACTIVITY AND GENERALLY INDICATES A LARGE SHIELD OF
MAINLY LIGHT TO MODERATE RAIN REMAINING POSSIBLE THROUGH THE MID-
MORNING HOURS BEFORE DIMINISHING. LATER THIS AFTERNOON THE LATEST
MODEL SOUNDINGS INDICATE SOME DRIER FILLING IN FROM THE SOUTHEAST
WITH PWS DROPPING TOWARD 1.6" OVER THE SE FLORIDA COAST AND
INCREASING TO OVER THE 2" MARK BETWEEN NAPLES AND THE LAKE LATER
TODAY. THIS GRADIENT WILL BE REFLECTED IN THE LATEST FORECAST
PACKAGE SHOWING THE GREATEST RAINFALL CHANCES ALONG THE SOUTHEAST
FLORIDA COAST THROUGH THE MORNING HOURS AND ACROSS THE INTERIOR AND
LAKE REGION LATER THIS AFTERNOON THROUGH THIS EVENING. MONDAY
THROUGH TUESDAY...CONDITIONS ARE EXPECTED TO TREND BACK TOWARD
NORMAL AS SOME ADDITIONAL MID-LEVEL DRY AIR MOVES INTO THE AREA.
EASTERLY LOW-LEVEL FLOW UP TO 700 MB WILL PERSIST THROUGH THIS
TIME...WHICH WILL KEEP THE DIURNALLY DRIVEN CONVECTIVE ACTIVITY
FOCUSED INLAND AND TOWARD THE GULF COAST EACH AFTERNOON/EVENING.
/85
.LONG TERM (WEDNESDAY-FRIDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT AND
GENERALLY INDICATES FALLING UPPER HEIGHTS IN RESPONSE TO A DEEPENING
UPPER TROUGH ACROSS THE REGION. A FRONTAL BOUNDARY IS PROJECTED TO
SHIFT SOUTHWARD TOWARD AND POSSIBLY INTO THE LOCAL AREA BEFORE
STALLING. THE GFS AND ECMWF HAVE COME INTO BETTER AGREEMENT IN THIS
00Z CYCLE REGARDING THE SOUTHWARD PROGRESSION OF THIS BOUNDARY
MOVING INTO THE AREA BY THURSDAY DUE TO A SHORTWAVE WRAPPING AROUND
THE BASE OF THE UPPER TROUGH NORTH OF THE AREA AND SFC WAVE
DEVELOPING ALONG THE BOUNDARY OFF OF THE GA/SC COAST BY THURSDAY.
THIS SHOULD TRANSLATE TO A WET PATTERN FOR SOUTH FLORIDA WITH SW LOW-
LEVEL FLOW AHEAD OF THE BOUNDARY AND PLENTY OF DEEP LAYER MOISTURE.
THE HIGHEST RAINFALL PROBABILITIES ARE PROJECTED TO SET UP AND
FOCUSING ALONG THE EAST COAST AREAS EACH AFTERNOON GOING INTO THE
WEEKEND EACH DAY.
/85
&&
.AVIATION...
SHOWERS AND STORMS WERE ONGOING ACROSS THE ATLANTIC WATERS...AND
ISOLATED SHOWERS WERE MOVING BACK INTO THE EAST COAST NEAR KFLL.
SHOWERS MAY MOVE BACK INTO THE EAST COAST OVERNIGHT AND THEN TAPER
OFF IN THE MORNING. BRIEF MVFR/IFR CONDITIONS ARE POSSIBLE. GUIDANCE
IS INDICATING DRIER AIR MAY BEGIN MOVING INTO THE EASTERN PORTIONS
OF THE REGION IN THE AFTERNOON. SO REMOVED VCTS FOR THE EAST COAST
METRO AREAS FOR THE AFTERNOON HOURS. LIGHT WINDS EARLY THIS MORNING
WILL BECOME SOUTHEAST AROUND 10 KNOTS IN THE AFTERNOON...AND THEN
DIMINISH AGAIN IN THE EVENING. FOR KAPF...A WEAK GULF COAST SEA
BREEZE MAY DEVELOP IN THE AFTERNOON. THE BEST CHANCE OF STORMS NEAR
KAPF IS ALSO FORECAST TO BE IN THE AFTERNOON.
/84
&&
.MARINE...
AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE
MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO
MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY
HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL
BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING
WEEK WITH SOUTHEAST WINDS CONTINUING. A COLD FRONT WILL APPROACH
FROM THE NORTH AND MAY LEAD TO SOUTH AND SOUTHWEST WINDS BY THE END
OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 76 87 76 / 60 20 50 20
FORT LAUDERDALE 88 79 88 79 / 50 20 50 10
MIAMI 87 78 88 78 / 50 20 50 10
NAPLES 87 76 89 76 / 60 20 40 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION...85/AG
AVIATION....84/AK
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
349 AM EDT Sun Sep 14 2014
.Near Term [Through Today]...
The 11 pm EDT regional surface analysis showed a quasi-stationary
front from the southeast LA coast, through Columbus, GA, to the east
coast of NC. Outflow from the numerous storms Saturday evening had
flipped the winds across much of our forecast area to the north, but
that was not the cold front, and we expect these winds to return to
light E-SE flow later this morning. Vapor imagery and upper air data
showed a narrow ridge along the Gulf Coast, so we don`t expect any
further progress of the aforementioned front, and very little (if
any) Q-G forcing. However, deep layer moisture remains plentiful,
and mesoscale forcing and/or weak convergence near the nearby front
will help generate scattered deep moist convection this afternoon.
Our PoP is in the 30-50% range, with the highest PoP north of Dothan
and Albany (nearest the frontal system), and around the Panama City
area (where the CAMs show more favorable sea breeze forcing). Highs
will be in the lower to mid 90s. The synoptic environment doesn`t
appears favorable for widespread flooding and/or severe storms,
though we can`t completely rule out an isolated, marginal incident
of either.
.Short Term [Tonight Through Tuesday]...
Rain chances will be gradually increasing through the short term
period as the "dirty" upper level ridge (with plenty of deep layer
moisture still underneath it) continues to weaken over the next
couple of days, before being replaced by a slowly steepening trof
over the SE U.S. by Tuesday and Wednesday. Lingering PoPs this
evening will range from 30% over much of the interior, with a small
area of 40%s across N portions of our AL and GA zones. On Monday, as
the southerly flow increases over the region, PoPs will rise from
40% south and 30% north in the morning, to 50% south and 60% north
by the afternoon, and once again linger well into the evening hours.
On Tuesday, as the upper level trof begins to become better
established, widespread 60% PoPs (with even a few areas of 70%) are
expected across the CWA. This pattern change could result in the
potential for more widespread heavy rainfall over the region through
mid week, before a significant punch of drier air works into the
area from the northwest by the end of the week as mentioned in the
long term discussion below. Initially, temps should still average a
few degrees above climo, but high temps on Tuesday may need a slight
downward adjustment based on the final cloud cover and rainfall
chances.
.Long Term [Tuesday Night Through Saturday]...
Deep moisture will continue to be present across the area with a
stalled frontal boundary also in the vicinity. These ingredients
point to an unsettled period coming up with an above average chance
of rain on Tuesday and Wednesday. Some locally heavy rain is
possible given the weak boundary and deep tropical moisture
expected to be in place. A drying trend is possible for most of
the area with the exception of the southeast big bend near the end
of the week as the deepest moisture may get pushed to the south.
Daytime highs are expected to be near to slightly below normal
through most of the week.
&&
.Aviation...
[through 06z Monday] There were some mixed signals among the latest
NWP guidance for the overnight and early morning period. Based on
recent rain and satellite imagery (which showed a gradual clearing
trend across much of our forecast area), we think there is a good
chance for periods of low-end MVFR cigs and vis at KDHN, KECP, and
KABY between 10z and 14z. (The 02z HRRR forecast LIFR conditions,
while most of the MOS forecast high-end MVFR conditions). Generally
VFR conditions are expected by late morning through afternoon and
evening, except in isolated to scattered TSRA. The highest PoP is at
KECP. Elsewhere the PoP is currently too low to mention TSRA in the
TAFs.
&&
.Marine...
Winds and seas will remain a bit elevated across the offshore legs
today and Monday, as a trough of low pressure (the remnants of a
weak tropical disturbance) passes well to the south of the marine
area. Thereafter, light winds and low seas are expected over the
coastal waters as a weak surface pressure returns to the marine
area.
&&
.Fire Weather...
Red Flag conditions are not expected through at least mid week.
&&
.Hydrology...
Although areas of locally heavy rainfall will be possible through
mid-week, at this time it does not appear as though there will be
enough time or organization to this precipitation to cause a
widespread impact on our area rivers and streams. However, the
situation does still bear monitoring, and if the steepening of the
upper level trof and subsequent cold frontal passage are slightly
slower than expected, the hydrological outlook may need to be
re-visited.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 93 72 93 72 91 / 30 30 50 30 60
Panama City 90 77 89 76 88 / 50 30 50 30 60
Dothan 91 71 92 71 91 / 30 30 60 40 60
Albany 91 71 92 72 92 / 40 40 60 40 60
Valdosta 92 71 93 71 92 / 30 30 60 30 60
Cross City 92 71 91 71 91 / 30 30 50 30 60
Apalachicola 89 77 88 77 87 / 30 30 50 30 60
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...FOURNIER
SHORT TERM...GOULD
LONG TERM...DVD
AVIATION...FOURNIER
MARINE...GOULD
FIRE WEATHER...FOURNIER
HYDROLOGY...GOULD
AREA FORECAST DISCUSSION
NWS MIAMI FL
146 AM EDT SUN SEP 14 2014
.AVIATION...
SHOWERS AND STORMS WERE ONGOING ACROSS THE ATLANTIC WATERS...AND
ISOLATED SHOWERS WERE MOVING BACK INTO THE EAST COAST NEAR KFLL.
SHOWERS MAY MOVE BACK INTO THE EAST COAST OVERNIGHT AND THEN TAPER
OFF IN THE MORNING. BRIEF MVFR/IFR CONDITIONS ARE POSSIBLE. GUIDANCE
IS INDICATING DRIER AIR MAY BEGIN MOVING INTO THE EASTERN PORTIONS
OF THE REGION IN THE AFTERNOON. SO REMOVED VCTS FOR THE EAST COAST
METRO AREAS FOR THE AFTERNOON HOURS. LIGHT WINDS EARLY THIS
MORNING WILL BECOME SOUTHEAST AROUND 10 KNOTS IN THE
AFTERNOON...AND THEN DIMINISH AGAIN IN THE EVENING. FOR KAPF...A
WEAK GULF COAST SEA BREEZE MAY DEVELOP IN THE AFTERNOON. THE BEST
CHANCE OF STORMS NEAR KAPF IS ALSO FORECAST TO BE IN THE
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 927 PM EDT SAT SEP 13 2014/
UPDATE...
DEEP TROPICAL FLOW REMAINS IN PLACE ACROSS SOUTH FLORIDA AS
EVIDENCED ON THE 00Z MFL SOUNDING THIS EVENING. THE PWAT IS JUST
OVER TWO INCHES WHICH IS SLIGHTLY ABOVE THE AVERAGE FOR MID
SEPTEMBER. SATELLITE AND RADAR SIGNATURES ALSO REFLECT THIS WITH
AMPLE SHOWER ACTIVITY WITH SOME EMBEDDED TSRA. SO NO CHANGES ARE
PLANNED AT THIS TIME AND WILL KEEP HIGH END CHANCES FOR RAIN
THROUGH THE NIGHT.
KOB
PREV DISCUSSION... /ISSUED 812 PM EDT SAT SEP 13 2014/
AVIATION...
EXTENSIVE CLUSTER OF SHOWERS AND THUNDERSTORMS THAT EXITED CUBA
THIS AFTERNOON IS PROGRESSING INTO MIAMI-DADE COUNTY AT TAF
ISSUANCE TIME. TEMPO TSRA GROUPS FOR ALL MIAMI-DADE TERMINALS
THROUGH 2Z...WITH VCTS AREAWIDE UNTIL 6Z. LOCALLY GUSTY WINDS...35
KNOTS CANT BE RULED OUT...AND SIGNIFICANT RESTRICTIONS POSSIBLE
WITH THIS ACTIVITY. BY MIDNIGHT...UNCERTAIN ON SHWR/TSTM COVERAGE
AS GUIDANCES SUGGESTS CLIMATOLOGICALLY UNUSUAL OCCURRENCE OF
SHOWERS/TSTMS INTO SUNDAY MORNING. FOR NOW WILL HANDLE WITH
VCSH...ALTHOUGH PERIODS OF THUNDER QUITE POSSIBLE...ESPECIALLY
CONSIDERING LAST NIGHT HAD SIMILAR ACTIVITY. THUNDERSTORMS SHOULD
REINVIGORATE BY LATE MORNING. AWAY FROM CONVECTION...ESE WINDS 5
KTS OVERNIGHT...10-15 KTS SUNDAY.
PREV DISCUSSION... /ISSUED 348 PM EDT SAT SEP 13 2014/
DISCUSSION...
THE LATEST CONSENSUS OF THE MODEL GUIDANCE...BOTH THE GLOBAL
MODELS AND THE LATEST HRRR RUN...INDICATE THE POTENTIAL FOR
SHOWERS AND THUNDERSTORMS TO FORM ACROSS THE FLORIDA STRAITS THIS
EVENING AND AFFECT THE SOUTHERN PORTIONS OF SOUTH FLORIDA AND
ADJACENT WATERS LATER THIS EVENING AND POSSIBLY CONTINUING INTO
THE EARLY MORNING HOURS ON SUNDAY. RECENT SATELLITE IMAGERY AND
RADAR RETURNS INDICATE THIS PROCESS IS ALREADY UNDERWAY WITH BANDS
OF SHOWERS AND THUNDERSTORMS OBSERVED ACROSS THE FLORIDA STRAITS.
OVER NIGHT AND INTO SUNDAY...A BROAD AREA OF SURFACE LOW PRESSURE
ACROSS THE EASTERN GULF WILL CONTINUE TO TRACK WESTWARD INTO THE
CENTRAL GULF. THE MORE RECENT GUIDANCE HAS CONSISTENTLY BEEN
INDICATING THAT DEEP TROPICAL MOISTURE WILL CONTINUE TO LINGER
ACROSS SOUTH FLORIDA AND ADJACENT WATERS WITH LOW LEVEL MASS AND
MOISTURE CONVERGENCE CONTINUING ACROSS THE REGION INTO SUNDAY
MORNING. IN ADDITION THE UPPER LEVEL WINDS COULD BE FAVORABLE FOR
SPEED DIVERGENCE DURING THE AFTERNOON HOURS. DAY TIME HEATING AND
WITH THE LINGERING DEEP MOISTURE WILL ALLOW FOR AFTERNOON
CONVECTION ON SUNDAY WITH THE GREATEST COVERAGE OF SHOWERS AND
THUNDERSTORMS EXPECTED INLAND AND WEST.
FOR MONDAY AND TUESDAY...SOME RELATIVELY DRIER AIR IS FORECAST TO
ENTER THE REGION ALTHOUGH THE GUIDANCE CONSENSUS INDICATES THAT
LINGERING MOISTURE COULD BE SUFFICIENT FOR AFTERNOON SHOWERS AND
THUNDERSTORMS...MAINLY OVER THE THE PENINSULA. THE EXTENDED
GUIDANCE CONTINUES TO SUGGEST THAT LATE NEXT WEEK DEEP MOISTURE
COULD EXTEND FROM THE YUCATAN PENINSULA NORTHEASTWARD ACROSS SOUTH
FLORIDA AND INTO THE WESTERN ATLANTIC WITH A LARGE AMPLITUDE UPPER
LEVEL TROUGH DEEPENING INTO THE CENTRAL GULF. THIS PATTERN IS
FORECAST TO LINGER INTO NEXT WEEKEND WITH THE POTENTIAL FOR
WIDESPREAD LOCAL CONVECTION.
MARINE...
MAINLY EASTERLY WINDS ARE FORECAST TO BE IN THE 10 TO 15 KNOT
RANGE ACROSS THE REGIONAL WATERS TONIGHT THROUGH SUNDAY THEN
SLOWLY DECREASING INTO EARLY NEXT WEEK WHILE REMAINING EASTERLY.
REGIONAL SEAS ARE FORECAST TO BE MAINLY AROUND 2 FEET OR LESS THE
REMAINDER OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 76 87 76 / 60 20 50 20
FORT LAUDERDALE 88 79 88 79 / 50 20 50 10
MIAMI 87 78 88 78 / 50 20 50 10
NAPLES 87 76 89 76 / 60 20 40 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...85/AG
LONG TERM....85/AG
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1004 PM CDT MON SEP 15 2014
.DISCUSSION...
221 PM CDT
TONIGHT...
FRONTAL BOUNDARY THIS AFTERNOON CONTINUES TO SLIDE SOUTHEAST ACROSS
THE FORECAST AREA. VISIBLE IMAGERY ALONG AND JUST AHEAD OF THE
BOUNDARY INDICATED SOME VERTICAL GROWTH TO THE CLOUDS...SUGGESTIVE
OF SOME INSTABILITY. THERE HAS BEEN SOME SPOTTY CONVECTION ACROSS
NORTHEAST MO STRETCHING EAST THROUGH IL/CENTRAL IN BUT SOUTH OF THE
CWFA. DESPITE CONSIDERABLE SOLAR SHIELDING HAS BEEN ABLE TO KEEP
TEMPS IN THE 50S...WITH A FEW LOCATIONS BEING ABLE TO NUDGE TO ARND
60. WINDS WILL SHIFT NORTHWEST/NORTH BEHIND THE BOUNDARY WITH MUCH
DRIER/COOLER AIR STEADILY FILTERING INTO THE REGION OVERNIGHT.
PRECIP WILL COME TO AN END LATER THIS AFTN/EARLY EVE...WITH JUST A
FEW LINGERING SHOWERS ALONG AND EAST OF GIBSON CITY TO FOWLER. TEMPS
OVERNIGHT WILL COOL INTO THE LOW/MID 40S...WITH A FEW OF THE
TRADITIONALLY COOL SPOTS POSSIBLY DIPPING INTO THE UPR 30S BEFORE
DAYBREAK TUE. MEANWHILE CLOSER TO DOWNTOWN CHICAGO...THE URBAN HEAT
ISLAND SHUD AID IN KEEPING TEMPS IN THE UPR 40S TO ARND 50. THE ONLY
WILDCARD FOR OVERNIGHT LOWS WILL BE SKY COVER/WINDS...WHICH WITH
HIGH PRESSURE BUILDING IN SHUD ERODE/DIMINISH.
THERE IS ALSO SOME CONCERN THAT WITH THE LACK MIXING THIS AFTN AND
EXPECTED TEMPS BEING COOLER THAN AFTN DEW PTS...COUPLED WITH LIGHT
WINDS...COULD POINT TOWARDS PATCHY FOG DEVELOPING AWAY FROM THE
METRO AREA.
TUESDAY THROUGH THURSDAY...
RATHER BENIGN PATTERN FOR A GOOD PORTION OF THE WEEK. BROAD
ANTI-CYCLONIC FLOW WILL BUILD INTO THE REGION TUESDAY...WITH THE
MID-LVL TROUGH PIVOTING EAST. THE LONGWAVE PATTERN WILL LIKELY KEEP
THE REGION IN A CONTINUED NORTHWEST FLOW AS MID-LVL RIDGING RETURNS
TO THE WESTERN CONUS. GUIDANCE SUGGESTS THE SFC RIDGE THAT ARRIVES
TUE WILL SHIFT EAST...HOWEVER ANOTHER DOME OF HIGH PRESSURE FROM
CANADA IS THEN POISED TO SLIDE SOUTH AND CONTINUE THE DRY/COOL
WEATHER WED/THUR. TEMPS WILL GENERALLY REMAIN IN THE MID/UPR
60S...BUT POSSIBLY REACH 70 DEG IN SEVERAL AREAS FOR THUR. ABUNDANT
SUNSHINE IS EXPECTED EACH OF THE NEXT SEVERAL DAYS AS WELL.
OVERNIGHT LOWS WILL ALSO DIP INTO THE 40S TUE NGT/WED NGT...THEN
WITH THE SFC RIDGE BEGINNING TO PUSH EAST THUR NGT TEMPS COULD HOLD
ARND 50.
CONFIDENCE...HIGH.
FRIDAY THROUGH SUNDAY...
WITH THE SFC RIDGE POISED TO PUSH EAST OF THE REGION FRI...FLOW WILL
BE TURNING SOUTHERLY AND THE MID-LVL WAVE STARTING TO FLATTEN.
ENSEMBLES CONTINUE TO SHOW CONSIDERABLE SPREAD ON TIMING OF
PRECIP/MOISTURE RETURNING...WITH MOST MEMBERS POINTING TOWARDS FRI
NGT. THE ATMOSPHERE WILL MODERATE BY FRI/SAT WITH TEMPS IN THE
MID/UPR 70S...OR MORE SEASONAL. SAT APPEARS TO BE THE MOST FAVORABLE
PERIOD TO SEE SPOTTY SHOWERS/THUNDERSTORMS AS A MID-LVL TROUGH
DEVELOPS OVER THE CENTRAL PLAINS AND NEARS THE REGION SAT AFTN/EVE.
THEN FOR THE SECOND HALF OF THE WEEKEND SFC RIDGING IS PROGGED TO
RETURN TO THE REGION.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LIGHT WEST TO NORTHWEST WINDS TUESDAY. LAKE BREEZE EXPECTED TO
STAY TO THE EAST.
MDB
//DISCUSSION...UPDATED 03Z...
CLOUDS CONTINUE TO EXIT TO THE SOUTH WITH SKIES AT GYY BEING THE
MAIN CHALLENGE OVERNIGHT. SATELLITE DOES SHOW A NARROW BAND OF
LAKE STRATUS OFF THE SE WI AND NE IL SHORE LINE. WILL CONTINUE
WITH MVFR CIGS AT GYY INTO THE OVERNIGHT WITH THE IDEA THAT THE
CLOUD BAND WOULD SHIFT JUST TO THE EAST OVERNIGHT. CLOUD BASE
HEIGHT MAY NEED ADJUSTMENT AS WELL BUT TEMP-DEWPOINT SPREADS OVER
THE LAKE AND FORECAST SOUNDINGS SUGGEST 1500-2000 FT. NOT OVERLY
CONFIDENT IN THE DURATION OF CIGS THOUGH. THE OTHER CHALLENGE WILL
BE PATCHY FOG POTENTIAL OVERNIGHT...ESPECIALLY AT RFD/DPA. WILL
CONTINUE WITH BCFG AND TEMPO MVFR VSBY FOR NOW.
FROM 00Z...
FRONTAL BOUNDARY IS NOW APPROACHING MDW AND WILL PASS GYY EARLY
THIS EVENING TURNING WINDS NORTHERLY WITH AN INITIAL INCREASE IN
SPEED TO 10-15 KT. SPEEDS WILL SETTLE UNDER 10 KT THROUGH EARLY
EVENING BEHIND THE FRONT THOUGH GYY MAY KEEP SPEEDS ABOVE 10 KT
INTO MID EVENING. SATELLITE SHOWS THE BACK EDGE OF THE MAIN CLOUD
SHIELD MOVING QUICKLY SOUTHEAST WITH THE DIURNAL STRATO CU TO THE
NORTHWEST QUICKLY DISSIPATING. EXPECT SKIES TO CLEAR BY MID
EVENING ACROSS THE IL TERMINALS WITH LAKE EFFECT PROCESSES
POTENTIALLY KEEPING MVFR CLOUDS AT GYY INTO THE OVERNIGHT. SOME
RESIDUAL LOW LEVEL MOISTURE MAY ALLOW FOR SOME PATCHY OR SHALLOW
FOG OVERNIGHT AT RFD/DPA AS WINDS DIMINISH. NORTHWEST WINDS WILL
BECOME WESTERLY UNDER 10 KT AT THE IL TERMINALS TUESDAY. A LAKE
BREEZE WILL LIKELY DEVELOP BY MIDDAY BRINGING NE WINDS TO GYY BUT
THE INLAND PUSH LOOKS TO BE SLOW GIVEN THE MINIMAL LAKE-LAND TEMP
DIFFERENCE SO WILL KEEP IT EAST OF ORD/MDW FOR NOW. SOME SCATTERED
STRATO CU IS EXPECTED TO DEVELOP LATE MORNING THEN LIFT/DISSIPATE
THROUGH THE AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN WEST TO NORTHWEST WINDS TUESDAY. MEDIUM-HIGH
CONFIDENCE ANY LAKE BREEZE WILL REMAIN EAST.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. LIGHT WEST WINDS. LAKE BREEZE POSSIBLE.
THURSDAY...VFR. EAST WINDS.
FRIDAY...VFR. BREEZY SOUTH WINDS.
SATURDAY...CHANCE TSRA. MVFR POSSIBLE. BREEZY SOUTHWEST WINDS.
SUNDAY...SLIGHT CHANCE TSRA. VFR. WEST WINDS.
MDB
&&
.MARINE...
246 PM CDT
WEAK LOW PRESSURE WILL PUSH EAST THROUGH THE OHIO VALLEY AND
DISSIPATE THIS EVENING AS HIGH PRESSURE MOVES INTO THE MID
MISSOURI VALLEY TONIGHT. AHEAD OF THE HIGH A WEAK COLD FRONT WILL
SPREAD DOWN THE REMAINDER OF THE LAKE THIS EVENING AND BRIEFLY
INCREASE NORTH WINDS TO NEAR 20 KT THE HIGH WILL WEAKEN AND MOVE
OVER LAKE MICHIGAN ON TUESDAY. LOW PRESSURE OVER HUDSON BAY WILL
SPREAD INTO QUEBEC ON WEDNESDAY AS HIGH PRESSURE PUSHES SOUTH OUT
OF NORTHERN MANITOBA. AHEAD OF THE HIGH THE SOUTHWEST GRADIENT
INCREASES WITH WINDS 15 TO 25 KT FOR THE NORTH HALF OF THE LAKE. THE
HIGH REACHES LAKE SUPERIOR THURSDAY EVENING AND WILL PUSH A COLD
FRONT DOWN THE LAKE THURSDAY NIGHT. THIS HIGH WILL THEN MOVE TO
THE EASTERN LAKES BY LATE THURSDAY INTO FRIDAY AS SEVERAL LOWS
ORGANIZE IN THE CENTRAL PLAINS AND CANADIAN PRAIRIES.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion...Corrected format
NATIONAL WEATHER SERVICE LINCOLN IL
907 PM CDT Mon Sep 15 2014
.UPDATE...
ISSUED AT 900 PM CDT MON SEP 15 2014
Showers and drizzle are departing quickly to the southeast, with
the back edge of the clouds approaching faster than previously
expected as well. The latest HRRR is indicating a band of low
clouds are expected to redevelop behind the clearing, moving into
our counties from the northeast toward Lake Michigan. Low level
wind patterns and obs from that area show some support for that
solution. Have updated the sky grids to acknowledge both the
initial clearing and subsequent clouds from the NE for a few hours
after. Any areas that clear out will have a good chance of seeing
fog develop. The light winds later tonight could set the stage for
locally dense fog, especially NW of I-55 where clearing will
develop sooner. Dewpoints will remain relatively high for enough
hours after clearing that lows will drop very close to the
dewpoint in those areas. Added fog to the weather grids
accordingly. Updated info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 321 PM CDT MON SEP 15 2014
Storm system still impacting Central Illinois ahead of an
approaching boundary. Some low clouds and developing fog in the
wake of the showers hint to the main issues going into the overnight
hours tonight. Showers and thunderstorms should begin to wrap up
this evening but wet, misty, and low clouds should continue for a
little while at least. Satellite imagery showing the low clouds
hanging around a bit after the wind shift/boundary moves through
with the NW/N winds. Cooler tonight...but coolest in the NW where
most likely to see some clearing. Temps may bottom out locally if
the cigs clear in the overnight. Either way, enhanced llvl moisture
will bring with it the chance for fog development. For now,
question is between dense fog and very low stratus. Stratus already
developing and see no reason to break that trend, so only putting in
patchy fog mention in the overnight hours.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 321 PM CDT MON SEP 15 2014
The medium and long range models are in generally good agreement
that a progressive upper level flow pattern will dominate through
the next seven days.
Surface high pressure from the northern Plains will work its way
toward the Midwest Tuesday, resulting in a clearing sky and a
continuation of cooler than normal temperatures. A weak shortwave
trough in the upper level northwest flow will approach the
mid-Mississippi River valley Wednesday. However, an abundance of dry
air in the lower levels should keep central and eastern IL
rain-free. Would not be surprised to see a sprinkle or two in areas
southwest of a Rushville-Springfield line. Will hold off on the
mention of that for now as the favorable moisture and lift appears
to stay along and west of the MS River.
Anticyclonic low level flow will continue to dominate through
Thursday and Friday keeping rain out of the forecast. A return,
southerly flow Friday will finally allow temperatures to climb
toward seasonal levels in the 75-80 range across most of central and
southeast IL.
Will keep the potential for showers and thunderstorms in the
forecast west of I-57 Saturday, and across all of central and
eastern IL Saturday night. The European and GFS models are actually
in quite good agreement that an upper level trough will advance from
the Rockies Friday to the Midwest later Saturday. The southerly low
level flow will advect plenty of moisture ahead of the surface cold
front, resulting in showers and thunderstorms. However, there is the
potential for heavy rain from this system, particularly according to
the GFS solution. The GFS depicts the remnants of Hurricane Odile,
currently in the southern California Baja region, ejecting toward
the central U.S. with deep tropical moisture. This would easily
result in 1-3" of rain across much of the forecast area Saturday
into early Sunday. However, the European and Canadian models are not
buying into this solution at the moment. As a result, will watch
this potential for the next several forecast runs before introducing
a mention of heavy rain.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 700 PM CDT MON SEP 15 2014
Showers and/or drizzle will linger for another hour or two at the
terminal sites except PIA, which is seeing ceiling heights rise to
VFR periodically due to dry air mixing down already. Satellite and
observations are indicating MVFR will return to PIA for several
more hours before some clearing arrives. CMI is the only LIFR
site, with IFR at SPI/BMI/DEC due to low cigs and vis. Forecast
soundings and HRRR output still show progressively improving
conditions by late evening, with high pressure building behind the
departing cold front. Therefore, have kept the clearing trends in
the cloud cover, with fog formation likely in any areas that clear
out. Went LIFR or VLIFR fog FROM 11Z-13Z for the northern
terminals of PIA/BMI/CMI, and IFR at SPI/DEC. The timing may need
to be adjusted, but feeling more confident that low level moisture
will become low stratus and fog across the board.
VFR conditions should develop quickly Tuesday morning with mixing
of very dry air just above the moisture layer.
Any residual WNW winds will become N by late evening behind the
front. A few gusts to 18kt will be possible for an hour or two
past FROPA, then light winds should develop the rest of the night
and into Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...HJS
LONG TERM...MILLER
AVIATION...SHIMON
AREA FORECAST DISCUSSION...CORRECTED
NWS LINCOLN IL
715 PM CDT MON SEP 15 2014
.SHORT TERM...(TONIGHT)
ISSUED AT 321 PM CDT MON SEP 15 2014
STORM SYSTEM STILL IMPACTING CENTRAL ILLINOIS AHEAD OF AN
APPROACHING BOUNDARY. SOME LOW CLOUDS AND DEVELOPING FOG IN THE
WAKE OF THE SHOWERS HINT TO THE MAIN ISSUES GOING INTO THE OVERNIGHT
HOURS TONIGHT. SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO WRAP UP
THIS EVENING BUT WET, MISTY, AND LOW CLOUDS SHOULD CONTINUE FOR A
LITTLE WHILE AT LEAST. SATELLITE IMAGERY SHOWING THE LOW CLOUDS
HANGING AROUND A BIT AFTER THE WIND SHIFT/BOUNDARY MOVES THROUGH
WITH THE NW/N WINDS. COOLER TONIGHT...BUT COOLEST IN THE NW WHERE
MOST LIKELY TO SEE SOME CLEARING. TEMPS MAY BOTTOM OUT LOCALLY IF
THE CIGS CLEAR IN THE OVERNIGHT. EITHER WAY, ENHANCED LLVL MOISTURE
WILL BRING WITH IT THE CHANCE FOR FOG DEVELOPMENT. FOR NOW,
QUESTION IS BETWEEN DENSE FOG AND VERY LOW STRATUS. STRATUS ALREADY
DEVELOPING AND SEE NO REASON TO BREAK THAT TREND, SO ONLY PUTTING IN
PATCHY FOG MENTION IN THE OVERNIGHT HOURS.
&&
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 321 PM CDT MON SEP 15 2014
THE MEDIUM AND LONG RANGE MODELS ARE IN GENERALLY GOOD AGREEMENT
THAT A PROGRESSIVE UPPER LEVEL FLOW PATTERN WILL DOMINATE THROUGH
THE NEXT SEVEN DAYS.
SURFACE HIGH PRESSURE FROM THE NORTHERN PLAINS WILL WORK ITS WAY
TOWARD THE MIDWEST TUESDAY, RESULTING IN A CLEARING SKY AND A
CONTINUATION OF COOLER THAN NORMAL TEMPERATURES. A WEAK SHORTWAVE
TROUGH IN THE UPPER LEVEL NORTHWEST FLOW WILL APPROACH THE
MID-MISSISSIPPI RIVER VALLEY WEDNESDAY. HOWEVER, AN ABUNDANCE OF DRY
AIR IN THE LOWER LEVELS SHOULD KEEP CENTRAL AND EASTERN IL
RAIN-FREE. WOULD NOT BE SURPRISED TO SEE A SPRINKLE OR TWO IN AREAS
SOUTHWEST OF A RUSHVILLE-SPRINGFIELD LINE. WILL HOLD OFF ON THE
MENTION OF THAT FOR NOW AS THE FAVORABLE MOISTURE AND LIFT APPEARS
TO STAY ALONG AND WEST OF THE MS RIVER.
ANTICYCLONIC LOW LEVEL FLOW WILL CONTINUE TO DOMINATE THROUGH
THURSDAY AND FRIDAY KEEPING RAIN OUT OF THE FORECAST. A RETURN,
SOUTHERLY FLOW FRIDAY WILL FINALLY ALLOW TEMPERATURES TO CLIMB
TOWARD SEASONAL LEVELS IN THE 75-80 RANGE ACROSS MOST OF CENTRAL AND
SOUTHEAST IL.
WILL KEEP THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS IN THE
FORECAST WEST OF I-57 SATURDAY, AND ACROSS ALL OF CENTRAL AND
EASTERN IL SATURDAY NIGHT. THE EUROPEAN AND GFS MODELS ARE ACTUALLY
IN QUITE GOOD AGREEMENT THAT AN UPPER LEVEL TROUGH WILL ADVANCE FROM
THE ROCKIES FRIDAY TO THE MIDWEST LATER SATURDAY. THE SOUTHERLY LOW
LEVEL FLOW WILL ADVECT PLENTY OF MOISTURE AHEAD OF THE SURFACE COLD
FRONT, RESULTING IN SHOWERS AND THUNDERSTORMS. HOWEVER, THERE IS THE
POTENTIAL FOR HEAVY RAIN FROM THIS SYSTEM, PARTICULARLY ACCORDING TO
THE GFS SOLUTION. THE GFS DEPICTS THE REMNANTS OF HURRICANE ODILE,
CURRENTLY IN THE SOUTHERN CALIFORNIA BAJA REGION, EJECTING TOWARD
THE CENTRAL U.S. WITH DEEP TROPICAL MOISTURE. THIS WOULD EASILY
RESULT IN 1-3" OF RAIN ACROSS MUCH OF THE FORECAST AREA SATURDAY
INTO EARLY SUNDAY. HOWEVER, THE EUROPEAN AND CANADIAN MODELS ARE NOT
BUYING INTO THIS SOLUTION AT THE MOMENT. AS A RESULT, WILL WATCH
THIS POTENTIAL FOR THE NEXT SEVERAL FORECAST RUNS BEFORE INTRODUCING
A MENTION OF HEAVY RAIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 700 PM CDT MON SEP 15 2014
SHOWERS AND/OR DRIZZLE WILL LINGER FOR ANOTHER HOUR OR TWO AT THE
TERMINAL SITES EXCEPT PIA, WHICH IS SEEING CEILING HEIGHTS RISE TO
VFR PERIODICALLY DUE TO DRY AIR MIXING DOWN ALREADY. SATELLITE AND
OBSERVATIONS ARE INDICATING MVFR WILL RETURN TO PIA FOR SEVERAL
MORE HOURS BEFORE SOME CLEARING ARRIVES. CMI IS THE ONLY LIFR
SITE, WITH IFR AT SPI/BMI/DEC DUE TO LOW CIGS AND VIS. FORECAST
SOUNDINGS AND HRRR OUTPUT STILL SHOW PROGRESSIVELY IMPROVING
CONDITIONS BY LATE EVENING, WITH HIGH PRESSURE BUILDING BEHIND THE
DEPARTING COLD FRONT. THEREFORE, HAVE KEPT THE CLEARING TRENDS IN
THE CLOUD COVER, WITH FOG FORMATION LIKELY IN ANY AREAS THAT CLEAR
OUT. WENT LIFR OR VLIFR FOG FROM 11Z-13Z FOR THE NORTHERN
TERMINALS OF PIA/BMI/CMI, AND IFR AT SPI/DEC. THE TIMING MAY NEED
TO BE ADJUSTED, BUT FEELING MORE CONFIDENT THAT LOW LEVEL MOISTURE
WILL BECOME LOW STRATUS AND FOG ACROSS THE BOARD.
VFR CONDITIONS SHOULD DEVELOP QUICKLY TUESDAY MORNING WITH MIXING
OF VERY DRY AIR JUST ABOVE THE MOISTURE LAYER.
ANY RESIDUAL WNW WINDS WILL BECOME N BY LATE EVENING BEHIND THE
FRONT. A FEW GUSTS TO 18KT WILL BE POSSIBLE FOR AN HOUR OR TWO
PAST FROPA, THEN LIGHT WINDS SHOULD DEVELOP THE REST OF THE NIGHT
AND INTO TUESDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HJS
LONG TERM...MILLER
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
806 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 LOWER 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 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON SEP 15 2014
HARSH CHANGES IN STORE FOR 00 UTC TAFS ACROSS NORTHERN INDIANA.
PREFERENCE LIES TOWARD MORE OMINOUS LAV/RUC GUIDANCE ESPECIALLY
IN LIGHT OF WIDESPREAD NATURE OF RAIN SHOWERS THIS EVENING...AS
WELL AS SUBSTANTIVE MOISTURE ADDITION INTO BOUNDARY LAYER FROM
PRIOR RAFL THIS AM. SLIGHTLY ELEVATED MIXED/MOIST LAYER TO LIKELY
FOSTER STRATUS DEVELOPMENT/FILL IN THROUGH THIS EVENING. NOTABLE
FLOW WITHIN 1-2KFT ON ORDER OF 15-20 KNOTS LENDS SUPPORT FOR
STRATUS VERSUS DENSE FOG AS BEING THE PRIMARY/POSSIBLE SOLE
RESTRICTIVE MET COND OVERNIGHT. HIGHER MOISTURE CONTENT INVOF
KFWA/NERN INDIANA COULD EVEN ALLOW FOR LIFR CIGS EARLY TUE AM.
COOL NEAR SURFACE LAYER AMID LARGE LAKE/8H THERMAL DIFFERENTIAL
COULD DELAY IMPROVEMENT INTO VFR THROUGH LATE MORNING AT KSBN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...AGD
LONG TERM...STEINWEDEL
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1151 PM CDT SAT SEP 13 2014
.UPDATE...
ISSUED AT 1149 PM CDT SAT SEP 13 2014
A ROUGHLY 75 MILE WIDE AREA OF LOW CLOUDS...EVIDENT ON IR IMAGERY EXTENDING
NORTHEAST FROM NE KS...THROUGH NW IA INTO NW WI APPEARED TO BE
ASSOCIATED WITH AN AXIS OF MOISTURE CONVERGENCE AND WARM ADVECTION
AROUND THE 800 MB LEVEL AS SEEN ON THE 00Z KOMA SOUNDING. THIS
WILL CONTINUE TO PROGRESS EASTWARD OVERNIGHT FOLLOWING AN ELEVATED
WARM FRONT LINKED TO AN UPPER LEVEL TROUGH MOVING THROUGH
MANITOBA. WHILE THE LATEST RAP RUNS HAVE MOISTURE DEPICTED AT
THIS LEVEL MIGRATING EASTWARD INTO THE FORECAST AREA BY MORNING...THE
ASSOCIATED ISENTROPIC LIFT AND CONDENSATION PRESSURE DEFICITS
OVERALL DEPICT A WEAKENING TREND...SUGGESTING THIS DECK WILL BREAK
UP AND BECOME LESS ORGANIZED.
HAVE UPDATED THE FORECAST TO BRING IN THESE SCATTERED TO BROKEN
CLOUDS INTO MUCH OF EASTERN IA BY SUNRISE. EVEN SCATTERED CLOUDS
SHOULD LOWER THE POTENTIAL FOR FOG AND FROST AND HAVE REMOVED
MENTION IN THE FAR WEST...BUT WILL LEAVE IN OVER THE REMAINDER OF
THE FORECAST AREA WHERE THE TIMING SUGGESTS SKIES WILL BE AT
LEAST MOSTLY CLEAR THROUGH SUNRISE. WITH TEMPERATURES AND
DEWPOINTS RUNNING SIMILAR TO LAST NIGHT AT THIS TIME...FORECAST
MINS FROM THE UPPER 30S TO AROUND 40...WITH A FEW MID 30S IN
CENTRAL AND NORTHEAST VALLEYS...LOOK ON TRACK.
&&
.SYNOPSIS...
ISSUED AT 250 PM CDT SAT SEP 13 2014
LARGE AND SEASONABLY QUITE COOL EARLY FALL HIGH PRESSURE KEEPING
TEMPERATURES IN THE MID TO UPPER 50S WITH LIGHT WINDS AND JUST
ISOLATED CUMULUS CLOUDS. UPPER AIR ANALYSIS SHOWS NEXT SHORT WAVE
TO IMPACT REGION IS STILL 48 HOURS AWAY AND JUST ENTERING NW CONUS
WITH LIMITED MOISTURE SUGGESTING LIGHT RAIN AMOUNTS...IF ANY. LOTS
OF SW MONSOON MOISTURE WITH NEXT TROPICAL SYSTEM OFF MEXICO MAY
MAKE ITS WAY TOWARD AREA AGAIN...SIMILAR TO LAST EVENT...IN A WEEK
OR SO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 250 PM CDT SAT SEP 13 2014
SHORT TERM FORECAST CONFIDENCE ASSESSMENT...ABOVE AVERAGE TO WELL
ABOVE AVERAGE OR GOOD TO EXCELLENT. LITTLE SENSIBLE WEATHER ISSUES
WITH CLEAR SKIES AND LIGHT WINDS. STRONG VERIFICATION OF PERSISTENCE
AND LOCAL TOOLS SUGGEST TEMPERATURES PROGGED PER LOCAL TOOLS SHOULD
BE WITHIN A DEGREE OR TWO FOR MOST AREAS NEXT 24 HOURS.
TONIGHT...FAIR SKIES AND LIGHT TO CALM WINDS TO ALLOW FOR BL DECOUPLING
WITH PATCHY FOG POSSIBLE TOWARD MORNING IN LOW LYING PLACES. MINS PER
LOCAL TOOLS HAVE LOWERED 1 TO 2 DEGREES WITH SOME PLACES POSSIBLY STILL
A DEGREE OR SO STILL TOO MILD. LOWS SHOULD BE CLOSE TO BREAKING OR
TYING LOW RECORDS AT BRL/MLI.
SUNDAY...ANOTHER FAIR AND SEASONABLY COOL DAY WITH SOME HIGH CLOUDS
AND FEW/SCT COVERAGE OF FAIR WEATHER CUMULUS CLOUDS MID DAY. HIGHS
WITH SOUTH WINDS OF 5 TO 10 MPH AND MODIFICATION SHOULD BE MOSTLY
IN THE MIDDLE 60S WITH SOME UPPER 60S SW SECTIONS. THESE TEMPERATURES
WILL STILL BE 10 DEGREES OR SO COOLER THAN NORMAL FOR MID SEPTEMBER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 250 PM CDT SAT SEP 13 2014
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY...
FORECAST FOCUS ON THE NEXT RAIN EVENT ON MONDAY FOLLOWED BY A MAINLY
DRY EXTENDED...WITH TEMPERATURES REMAINING BELOW NORMAL.
SUNDAY NIGHT THROUGH MONDAY NIGHT...SIGNIFICANT UPPER LEVEL TROUGH
WILL SWING ACROSS THE REGION IN THE NORTHWEST FLOW. MODERATE TO
STRONG VERTICAL MOTION IS FORECAST BY THE MODELS WHICH WILL SQUEEZE
OUT THE INCREASING PRECIPITABLE WATER. HAVE RAISED POPS INTO THE
LIKELY CATEGORY WITH ROOM TO RAISE THEM EVEN FURTHER. THE RAIN
SHOULD ARRIVE INTO EASTERN IA WELL AFTER MIDNIGHT SUNDAY NIGHT THEN
SPREAD OVER ALL THE CWA MONDAY MORNING. I WILL WALK OUT THE RAIN IN
OUR EASTERN CWA SOMETIME MONDAY EVENING. RAINFALL AMOUNTS SHOULD
RANGE FROM ABOUT 0.15 INCH IN THE NORTH...AROUND 2 TENTHS ALONG THE
I-80 CORRIDOR AND UP TO 1/2 INCH IN THE SOUTH.
TEMPERATURES ARE PROBLEMATIC ON MONDAY WITH AN ALL-DAY RAIN OVER
MOST OF THE CWA WITH 850 MB TEMPERATURES OF +6 TO 10C OVER THE CWA.
WHILE GUIDANCE INDICATES HIGHS IN THE LOWER TO MID 60S THIS SEEMS
TOO WARM BASED ON LOCAL TECHNIQUES...AND HAVE LOWERED READINGS TO
NEAR 60. THIS STILL MAY BE TOO WARM AND HIGHS IN THE 50S MAY BE MORE
REASONABLE WHERE THE RAIN PERSISTS ALL DAY.
TUESDAY THROUGH THURSDAY...HIGH PRESSURE WILL BE IN CONTROL WITH A
DRY NORTHWEST FLOW EXPECTED DURING THIS TIME FRAME. TEMPERATURES
SHOULD MODERATE DURING THE WEEK WITH HIGHS IN THE 60S TUESDAY
WARMING INTO THE LOWER TO MID 70S THURSDAY.
FRIDAY INTO NEXT WEEKEND...LOW CONFIDENCE AS ECMWF BRINGS A ZONAL
FLOW INTO THE MIDWEST WITH THE POTENTIAL FOR THUNDERSTORMS ON THE
EDGE OF A BUILDING HEAT DOME IN THE SOUTHERN PLAINS. THE GFS REMAINS
DRY WITH A SHARPENING TROUGH PUSHING INTO THE PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1149 PM CDT SAT SEP 13 2014
AN AXIS OF SCATTERED TO BROKEN CLOUDS AROUND 5000 T0 6000 FEET
MAY MOVE INTO ESPECIALLY THE CID...DBQ AND MLI BETWEEN 4 AND 9 AM.
OTHERWISE...DEPARTING HIGH PRESSURE OVER THE GREAT LAKES WILL
CONTINUE TO INFLUENCE THE AREA WITH LIGHT SE TO SOUTH WINDS
THROUGH SUNDAY. CONDITIONS WILL LIKELY REMAIN VFR WELL INTO SUNDAY
EVENING...WITH LOWERING CLOUDS AND THEN RAIN EXPECTED TO
OVERSPREAD THE AREA JUST BEYOND THE FORECAST PERIOD.
&&
.CLIMATE...
ISSUED AT 250 PM CDT SAT SEP 13 2014
RECORD LOWS FOR SEPTEMBER 14...
MOLINE.........39 IN 1974
CEDAR RAPIDS...36 IN 1929
DUBUQUE........34 IN 1974
BURLINGTON.....38 IN 1974
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...SHEETS
CLIMATE...NICHOLS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1028 PM EDT Mon Sep 15 2014
...Forecast Update...
Issued 1028 PM EDT Mon Sep 15 2014
The widespread rain from earlier has decreased to just spotty light
rain showers. This should continue to be the case for the remainder
of the night.
Issued at 737 PM EDT Mon Sep 15 2014
Showers continue to move southeastward out of Indiana, generally
north of a Paoli-Louisville-Richmond line. Will continue with
likely/categorical PoPs for this area through the evening hours.
Coverage should taper off as the night wears on, with just some
patchy light rain or sprinkles expected after midnight. Clouds will
gradually thicken and lower, especially after midnight as a weak
cold front crosses the region.
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 (00Z TAF Update)...
Issued at 714 PM EDT Mon Sep 15 2014
A weak cold front along a CLE-IND-SGF line this evening will push to
the southeast, crossing central Kentucky between midnight and dawn.
This system will usher is scattered showers, as well as lowering
ceilings. Cigs should go sub 2k` after 06Z and will likely remain
there into the early daylight hours before slowly lifting over the
course of the day Tuesday. Winds will remain below 10 knots through
the period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....KJD
Long Term......RJS
Aviation.......13
AREA FORECAST DISCUSSION
NWS JACKSON KY
939 PM EDT MON SEP 15 2014
.UPDATE...
ISSUED AT 939 PM EDT MON SEP 15 2014
FIRST BATCH OF SHOWERS REALLY DISSIPATED UPON ARRIVAL. HOWEVER...A
SECOND SURGE HAS PUSHED INTO NORTH CENTRAL KENTUCKY AND IS HOLDING
TOGETHER A BIT BETTER. THIS AREA OF SHOWERS WILL SWING SOUTH ACROSS
AREAS MAINLY NORTH OF THE HAL ROGERS PARKWAY. THIS WILL PROVIDE A
PERIOD OF CATEGORICAL POPS FOR THE AREA OVER THE NEXT 2 TO 4 HOURS.
IT LOOKS LIKE COVERAGE SHOULD BACK OFF AGAIN TOWARDS MIDNIGHT UNTIL
THE COLD FRONT STARTS TO PUSH SOUTH TOWARDS 4 AM. HOWEVER...AT THIS
TIME...ISOLATED COVERAGE AT BEST IS STILL ANTICIPATED WITH THE ACTUAL
FRONT. UPDATED FORECAST HAS BEEN SENT.
UPDATE ISSUED AT 813 PM EDT MON SEP 15 2014
SHOWERS ACROSS THE SOUTH HAVE ENDED...BUT STILL WATCHING A COMPLEX OF
SHOWERS MOVING ACROSS NORTH CENTRAL KENTUCKY AND WILL BE SPREADING
ACROSS AREAS NORTH OF THE MOUNTAIN PARKWAY OVER THE COMING 2 TO 4
HOURS. THIS ACTIVITY WILL MOVE ON THROUGH AND THEN WE WILL WAIT ON
THE COLD FRONT TO MOVE INTO THE AREA LATER TONIGHT...BRINGING THE
THREAT OF AN ISOLATED SHOWER BACK TO THE AREA BY DAWN. ADJUSTED
HOURLY POPS TO ACCOUNT FOR THESE TRENDS. OTHERWISE...NO OTHER CHANGES
WARRANTED AT THIS TIME.
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 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 813 PM EDT MON SEP 15 2014
A COLD FRONT WILL MARCH SOUTH ACROSS EASTERN KENTUCKY LATE TONIGHT
THROUGH TUESDAY. WHILE VFR CIGS WILL START OFF THE NIGHT AS THE FRONT
PUSHES THROUGH LATER ON...MVFR CIGS WILL DEVELOP AND LAST WELL INTO
THE DAY TOMORROW. IN FACT...NO ALL THAT CONFIDENT WE WILL LOSE THE
MVFR CIGS TOMORROW ESPECIALLY ACROSS THE SOUTH. FOR NOW WILL GO
PESSIMISTIC WITH THE SKY COVER. THIS TIME AROUND...IT LOOKS LIKE CIGS
SHOULD STAY MVFR AND FAIL TO GET NEAR AIRPORT MINIMUMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
813 PM EDT MON SEP 15 2014
.UPDATE...
ISSUED AT 813 PM EDT MON SEP 15 2014
SHOWERS ACROSS THE SOUTH HAVE ENDED...BUT STILL WATCHING A COMPLEX OF
SHOWERS MOVING ACROSS NORTH CENTRAL KENTUCKY AND WILL BE SPREADING
ACROSS AREAS NORTH OF THE MOUNTAIN PARKWAY OVER THE COMING 2 TO 4
HOURS. THIS ACTIVITY WILL MOVE ON THROUGH AND THEN WE WILL WAIT ON
THE COLD FRONT TO MOVE INTO THE AREA LATER TONIGHT...BRINGING THE
THREAT OF AN ISOLATED SHOWER BACK TO THE AREA BY DAWN. ADJUSTED
HOURLY POPS TO ACCOUNT FOR THESE TRENDS. OTHERWISE...NO OTHER CHANGES
WARRANTED AT THIS TIME.
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 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 813 PM EDT MON SEP 15 2014
A COLD FRONT WILL MARCH SOUTH ACROSS EASTERN KENTUCKY LATE TONIGHT
THROUGH TUESDAY. WHILE VFR CIGS WILL START OFF THE NIGHT AS THE FRONT
PUSHES THROUGH LATER ON...MVFR CIGS WILL DEVELOP AND LAST WELL INTO
THE DAY TOMORROW. IN FACT...NO ALL THAT CONFIDENT WE WILL LOSE THE
MVFR CIGS TOMORROW ESPECIALLY ACROSS THE SOUTH. FOR NOW WILL GO
PESSIMISTIC WITH THE SKY COVER. THIS TIME AROUND...IT LOOKS LIKE CIGS
SHOULD STAY MVFR AND FAIL TO GET NEAR AIRPORT MINIMUMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
651 PM CDT Mon Sep 15 2014
.UPDATE...
Issued at 651 PM CDT MON SEP 15 2014
Updated the grids, to reflect slight tsra chance all locations
through the evening. Greatest surface based instability is west of
I-55. However using Best LI computation off the RUC depicts
adequate elevated instability all locales. Doesn`t mean it will
amount to much. But will have it covered. Kept coverage wording
as isolated for now. Will have to tweak the winds a bit. Temps and
dew points in decent shape. Added mention of patchy light drizzle
post front aft 06z, as 1000-925mb rh really picks up. This lines
up with what our neighboring offices to our North and West have as
well in the grid depiction.
&&
.SHORT TERM...(Tonight through Wednesday night)
Issued at 116 PM CDT MON SEP 15 2014
Radar shows light shower activity to our north, associated with
the front, and to our south, associated with some warm air
advection that occurred ahead of the front. The front will move in
this evening, and thru the FA tonight. The HRR has been perhaps
the best model of the short term pcpn, particularly this morning,
but all more or less shrivel up the frontal precip as it moves
south and into our area. We`ll still maintain a 20 pop fa-wide,
and the northeast could see a few percentage points higher, but
we`ll monitor that in the near term and made adjustments
accordingly.
After fropa, drier air wedges in and down the column tmrw,
particularly late tmrw-tmrw night. This occurs as surface high
pressure works in and across the Ohio valley. By Wed., the high
has shifted east and some return flow warm air advection on its
backside introduces a small/slgt chance mention pops in the
Ozarks. This has been a fairly consistent signal and given the
extent of precip this morning from a similar signal, we`ll
continue to carry some low pops for Semo to cover it, Wed-Wed
night.
.LONG TERM...(Thursday through Monday)
Issued at 116 PM CDT MON SEP 15 2014
The first half of the long term portion of the forecast will see a
trof to the east and a ridge to the west, with our area becoming
more and more influenced by the ridge to the west. This will
result in rising heights and a subsequent warming of the profile.
Highs in the 70s earlier in the week will rebound to the 80s by
the weekend, and lows will do similarly, moving from the 50s to
the 60s in like manner and timing.
Dry weather is forecast into the first half of the weekend, but as
the surface high moves east, return flow kicks in ahead of a
developing frontal system. Jet energy spilling across the High
Plains will lower heights and help drive cylcogenesis and an
eventual front into and through our area, with fairly consistent
member signalling for pops coming in as early as Sat night, and
fropa Sunday. This should result in a return to 70s/50s by early
next week.
&&
.AVIATION...
Issued at 631 PM CDT MON SEP 15 2014
It will not be a very clean frontal passage with respect to
ceilings and visibilities for the 00z Tuesday TAF package. The
dynamics along the front will be more discrete this evening,
allowing for a sharp transition from VFR to IFR ceilings and MVFR
visibilities along the frontal zone.
The big question lies on whether the low level ridge will work
east or south toward 12z Tuesday. This would impact the degree and
speed of cold air advection and transition to higher ceilings/
cloud bases between 12z and 18z Tuesday.
For now, leaned closer to the GFS solution versus the NAM
solution, especially in the treament of precipitation chances and
ceilings around 12z Tuesday. Will need to monitor what develops
over southeast Kansas and southwest Missouri this evening and
adjust accordingly.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...CN
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
737 PM EDT Mon Sep 15 2014
...Forecast Update...
Issued at 737 PM EDT Mon Sep 15 2014
Showers continue to move southeastward out of Indiana, generally
north of a Paoli-Louisville-Richmond line. Will continue with
likely/categorical PoPs for this area through the evening hours.
Coverage should taper off as the night wears on, with just some
patchy light rain or sprinkles expected after midnight. Clouds will
gradually thicken and lower, especially after midnight as a weak
cold front crosses the region.
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 (00Z TAF Update)...
Issued at 714 PM EDT Mon Sep 15 2014
A weak cold front along a CLE-IND-SGF line this evening will push to
the southeast, crossing central Kentucky between midnight and dawn.
This system will usher is scattered showers, as well as lowering
ceilings. Cigs should go sub 2k` after 06Z and will likely remain
there into the early daylight hours before slowly lifting over the
course of the day Tuesday. Winds will remain below 10 knots through
the period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....KJD
Long Term......RJS
Aviation.......13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
714 PM EDT Mon Sep 15 2014
...Updated Aviation Discussion...
...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 (00Z TAF Update)...
Issued at 714 PM EDT Mon Sep 15 2014
A weak cold front along a CLE-IND-SGF line this evening will push to
the southeast, crossing central Kentucky between midnight and dawn.
This system will usher is scattered showers, as well as lowering
ceilings. Cigs should go sub 2k` after 06Z and will likely remain
there into the early daylight hours before slowly lifting over the
course of the day Tuesday. Winds will remain below 10 knots through
the period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....KJD
Long Term......RJS
Aviation.......13
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1121 PM EDT MON SEP 15 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 325 PM EDT MON SEP 15 2014
AFTER RAIN EXITS THE AREA THIS EVENING...HIGH TEMPERATURES IN THE
MID 60S TUESDAY WILL GRADUALLY WARM INTO THE MID 70S BY SATURDAY.
DRY AND COOL OVERNIGHT CONDITIONS MAY ALLOW PATCHY FROST TO DEVELOP
WEDNESDAY NIGHT OVER CENTRAL LOWER MICHIGAN. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE BEGINNING LATE FRIDAY.
&&
.UPDATE...
ISSUED AT 1121 PM EDT MON SEP 15 2014
SEEMS THE FOG IS BECOMING EVEN MORE EXTENSIVE THAN I THROUGH WITH
MY LAST UPDATE SO I ONCE AGAIN INCREASED THE FOG IN OUR GRIDS AND
EXTENDED THE FOG TILL 8-9 AM SINCE THE SUN COMES UP LATER NOW AND
THE WIND REMAINS LIGHT OVERNIGHT INTO TUESDAY MORNING. WE MAY NEED
A DENSE FOG ADVISORY BUT I AM NOT SURE ENOUGH TO ISSUE THAT JUST
YET. OTHERWISE OUR TEMPERATURE AND WIND FORECAST IS DOING FINE.
UPDATE ISSUED AT 757 PM EDT MON SEP 15 2014
I UPDATED OUR GRIDDED WEATHER FORECAST OVERNIGHT TO PUT PATCHY FOG
OVER MOST OF OUR CWA. THE LIGHT RAIN HAS IMPACTED MOST OF OUR CWA
LATE THIS AFTERNOON AND EVENING. THE RAIN IS NOW EXITING THE CWA
AND CLEARING WILL FOLLOW QUICKLY BEHIND THE ENDING OF THE RAIN.
WITH LIGHT SURFACE WINDS...I WOULD EXPECT AREA OF FOG TO DEVELOP
OVERNIGHT. THIS IS SHOWN WELL BY THE NAMDN5 SURFACE VISIBILITY
FORECAST AND CAN BE SEEN IN NAM MODEL SOUNDINGS TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EDT MON SEP 15 2014
MAIN CHALLENGE IN SHORT TERM IS TIMING THE EXIT OF RAIN...MOST OF
WHICH IS BEHIND THE SURFACE COLD FRONT CURRENTLY MOVING ACROSS THE
NORTHWEST FORECAST AREA. PRECIPITATION AMOUNTS UPSTREAM OVER
WISCONSIN HAVE NOT BEEN IMPRESSIVE - ONLY A FEW HUNDREDTHS IN SPOTS.
COVERAGE HOWEVER IS INCREASING AND EXPECT THIS TO CONTINUE IN THE
SHORT TERM. EXPECT A RAPID EXIT OF PRECIPITATION TO THE SOUTHEAST
THIS EVENING AND EARLY TONIGHT.
ADDED PATCHY FROST WEDNESDAY NIGHT FOR INTERIOR PORTIONS OF NORTH
CENTRAL MICHIGAN. SURFACE HIGH PRESSURE CENTERED OVER THE AREA WILL
BE FAVORABLE FOR RADIATION COOLING...BUT THIS COULD BE OFFSET BY
SOME LOW CLOUDINESS. THANKS APX FOR COORDINATION.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 325 PM EDT MON SEP 15 2014
THE PRIMARY FOCUS IS ON SHOWER AND TSTM POTENTIAL OVER THE WEEKEND
AND HOW WARM IT GETS.
STRONG WARM ADVECTION KICKS IN ON FRIDAY NIGHT IN RESPONSE TO THE
DIGGING H5 WAVE OVER THE NRN PLAINS. BEST FORCING IS CURRENTLY
PROGGED TO BE ACROSS UPR MI AND NRN LWR MI ON THE NOSE OF THE LOW
LEVEL JET... BUT CHANCE POPS ARE WARRANTED IN SW LWR MI AS THE WARM
FRONT LIFTS THROUGH.
WE SHOULD BE FIRMLY IN THE WARM SECTOR ON SATURDAY WITH MOST OF THE
CONVECTION TO OUR NORTH AND WEST. H8 TEMPS AROUND 15C AND DECENT
MIXING MAY ALLOW FOR HIGHS TOUCHING 80 DEGREES INLAND FROM LAKE
MICHIGAN. HOWEVER A FASTER COLD FRONT SOLUTION AND EARLIER ARRIVAL
OF CLOUDS/SHOWERS COULD MAKE IT DIFFICULT TO GET THAT WARM.
CURRENTLY THE SFC COLD FRONT/SHORTWAVE PASSAGE AND BEST CHANCE OF
RAIN IS PROGGED FOR SATURDAY NIGHT... FOLLOWED BY A COOL DOWN ON
SUNDAY AND MONDAY. THE NEW 12Z RUN OF THE ECMWF IS VERY AGGRESSIVE
WITH THE COLD ADVECTION NEXT MONDAY... SHOWING H8 TEMPS LESS THAN
ZERO INVADING THE STATE. THIS WOULD RESULT IN MORE IN THE WAY OF
CLOUDS AND A CHANCE OF LAKE EFFECT RAIN SHOWERS WHICH IS NOT
CURRENTLY IN THE FCST. IF THIS MODEL TREND CONTINUES THEN FUTURE
FORECASTS FOR A WEEK FROM NOW WILL NEED TO BE TRENDED MORE
PESSIMISTICALLY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 735 PM EDT MON SEP 15 2014
THE MAIN ISSUE TONIGHT IS WHAT HAPPENS WHEN THE RAIN ENDS? THE MID
CLOUDS SHOULD CLEAR FAIRLY QUICKLY AFTER THE RAIN ENDS BUT THE
SURFACE WINDS WILL BE LIGHT AND MOST AREA HAVE GOTTEN AT LEAST A
LITTLE RAIN THIS EVENING. SO THERE WOULD BE THE THREAT OF FOG
DEVELOPING OVERNIGHT. MODEL SOUNDING FROM THE RAP AND NAM SUGGEST
FOG IS POSSIBLE. THE NAMDNG5 SHOWS EXTENSIVE FOG OVER ALL OF THE
TAF SITES BY 12Z. THE ONLY PROBLEM IS WE HAVE AIR ADVECTION
TONIGHT AND THAT TYPICALLY MIXES THE DRY AIR DOWN TO THE BOTTOM OF
THE SOUNDING. SO I DID NOT PUT FOG IN THE TAFS... BUT IT MAY WELL
BE NEEDED TO BE ADDED.
OTHERWISE ONLY A FEW CUMULUS CLOUDS WITH BASES NEAR 4000 FT AGL
ARE EXPECTED TUESDAY.
&&
.MARINE...
ISSUED AT 325 PM EDT MON SEP 15 2014
NO HEADLINES ARE EXPECTED. THERE WILL BE A BRIEF UPTICK IN WAVES
OVERNIGHT WITH A SURGE OF WIND BEHIND THE COLD FRONT PASSING
THROUGH...BUT THEY SHOULD GENERALLY STAY WELL BELOW 4 FEET.
&&
.HYDROLOGY...
ISSUED AT 325 PM EDT MON SEP 15 2014
RIVERS CONTINUE RUNNING NEAR TO ABOVE NORMAL FOR MID SEPTEMBER.
SEVERAL DRY DAYS THIS WEEK WILL ENSURE THIS TREND CONTINUES. BY LATE
IN THE WEEK AND WEEKEND THERE WILL BE A THREAT FOR SHOWERS AND
THUNDERSTORMS AS A FRONT APPROACHES. IT IS TOO EARLY TO TELL HOW
MUCH RAINFALL IS POSSIBLE WITH THIS SYSTEM BUT SIGNIFICANT AMOUNTS
ARE NOT OUT OF THE QUESTION IF THE FRONT MOVES SLOWER AND ALSO
DEPENDING ON WHERE THE REMNANTS OF HURRICANE ODILE MOVE. A CLEARER
PICTURE WILL HOPEFULLY EVOLVE OVER THE NEXT COUPLE DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...MEADE
AVIATION...WDM
HYDROLOGY...HOVING
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
757 PM EDT MON SEP 15 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 325 PM EDT MON SEP 15 2014
AFTER RAIN EXITS THE AREA THIS EVENING...HIGH TEMPERATURES IN THE
MID 60S TUESDAY WILL GRADUALLY WARM INTO THE MID 70S BY SATURDAY.
DRY AND COOL OVERNIGHT CONDITIONS MAY ALLOW PATCHY FROST TO DEVELOP
WEDNESDAY NIGHT OVER CENTRAL LOWER MICHIGAN. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE BEGINNING LATE FRIDAY.
&&
.UPDATE...
ISSUED AT 757 PM EDT MON SEP 15 2014
I UPDATED OUR GRIDDED WEATHER FORECAST OVERNIGHT TO PUT PATCHY FOG
OVER MOST OF OUR CWA. THE LIGHT RAIN HAS IMPACTED MOST OF OUR CWA
LATE THIS AFTERNOON AND EVENING. THE RAIN IS NOW EXITING THE CWA
AND CLEARING WILL FOLLOW QUICKLY BEHIND THE ENDING OF THE RAIN.
WITH LIGHT SURFACE WINDS...I WOULD EXPECT AREA OF FOG TO DEVELOP
OVERNIGHT. THIS IS SHOWN WELL BY THE NAMDN5 SURFACE VISIBILITY
FORECAST AND CAN BE SEEN IN NAM MODEL SOUNDINGS TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EDT MON SEP 15 2014
MAIN CHALLENGE IN SHORT TERM IS TIMING THE EXIT OF RAIN...MOST OF
WHICH IS BEHIND THE SURFACE COLD FRONT CURRENTLY MOVING ACROSS THE
NORTHWEST FORECAST AREA. PRECIPITATION AMOUNTS UPSTREAM OVER
WISCONSIN HAVE NOT BEEN IMPRESSIVE - ONLY A FEW HUNDREDTHS IN SPOTS.
COVERAGE HOWEVER IS INCREASING AND EXPECT THIS TO CONTINUE IN THE
SHORT TERM. EXPECT A RAPID EXIT OF PRECIPITATION TO THE SOUTHEAST
THIS EVENING AND EARLY TONIGHT.
ADDED PATCHY FROST WEDNESDAY NIGHT FOR INTERIOR PORTIONS OF NORTH
CENTRAL MICHIGAN. SURFACE HIGH PRESSURE CENTERED OVER THE AREA WILL
BE FAVORABLE FOR RADIATION COOLING...BUT THIS COULD BE OFFSET BY
SOME LOW CLOUDINESS. THANKS APX FOR COORDINATION.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 325 PM EDT MON SEP 15 2014
THE PRIMARY FOCUS IS ON SHOWER AND TSTM POTENTIAL OVER THE WEEKEND
AND HOW WARM IT GETS.
STRONG WARM ADVECTION KICKS IN ON FRIDAY NIGHT IN RESPONSE TO THE
DIGGING H5 WAVE OVER THE NRN PLAINS. BEST FORCING IS CURRENTLY
PROGGED TO BE ACROSS UPR MI AND NRN LWR MI ON THE NOSE OF THE LOW
LEVEL JET... BUT CHANCE POPS ARE WARRANTED IN SW LWR MI AS THE WARM
FRONT LIFTS THROUGH.
WE SHOULD BE FIRMLY IN THE WARM SECTOR ON SATURDAY WITH MOST OF THE
CONVECTION TO OUR NORTH AND WEST. H8 TEMPS AROUND 15C AND DECENT
MIXING MAY ALLOW FOR HIGHS TOUCHING 80 DEGREES INLAND FROM LAKE
MICHIGAN. HOWEVER A FASTER COLD FRONT SOLUTION AND EARLIER ARRIVAL
OF CLOUDS/SHOWERS COULD MAKE IT DIFFICULT TO GET THAT WARM.
CURRENTLY THE SFC COLD FRONT/SHORTWAVE PASSAGE AND BEST CHANCE OF
RAIN IS PROGGED FOR SATURDAY NIGHT... FOLLOWED BY A COOL DOWN ON
SUNDAY AND MONDAY. THE NEW 12Z RUN OF THE ECMWF IS VERY AGGRESSIVE
WITH THE COLD ADVECTION NEXT MONDAY... SHOWING H8 TEMPS LESS THAN
ZERO INVADING THE STATE. THIS WOULD RESULT IN MORE IN THE WAY OF
CLOUDS AND A CHANCE OF LAKE EFFECT RAIN SHOWERS WHICH IS NOT
CURRENTLY IN THE FCST. IF THIS MODEL TREND CONTINUES THEN FUTURE
FORECASTS FOR A WEEK FROM NOW WILL NEED TO BE TRENDED MORE
PESSIMISTICALLY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 735 PM EDT MON SEP 15 2014
THE MAIN ISSUE TONIGHT IS WHAT HAPPENS WHEN THE RAIN ENDS? THE MID
CLOUDS SHOULD CLEAR FAIRLY QUICKLY AFTER THE RAIN ENDS BUT THE
SURFACE WINDS WILL BE LIGHT AND MOST AREA HAVE GOTTEN AT LEAST A
LITTLE RAIN THIS EVENING. SO THERE WOULD BE THE THREAT OF FOG
DEVELOPING OVERNIGHT. MODEL SOUNDING FROM THE RAP AND NAM SUGGEST
FOG IS POSSIBLE. THE NAMDNG5 SHOWS EXTENSIVE FOG OVER ALL OF THE
TAF SITES BY 12Z. THE ONLY PROBLEM IS WE HAVE AIR ADVECTION
TONIGHT AND THAT TYPICALLY MIXES THE DRY AIR DOWN TO THE BOTTOM OF
THE SOUNDING. SO I DID NOT PUT FOG IN THE TAFS... BUT IT MAY WELL
BE NEEDED TO BE ADDED.
OTHERWISE ONLY A FEW CUMULUS CLOUDS WITH BASES NEAR 4000 FT AGL
ARE EXPECTED TUESDAY.
&&
.MARINE...
ISSUED AT 325 PM EDT MON SEP 15 2014
NO HEADLINES ARE EXPECTED. THERE WILL BE A BRIEF UPTICK IN WAVES
OVERNIGHT WITH A SURGE OF WIND BEHIND THE COLD FRONT PASSING
THROUGH...BUT THEY SHOULD GENERALLY STAY WELL BELOW 4 FEET.
&&
.HYDROLOGY...
ISSUED AT 325 PM EDT MON SEP 15 2014
RIVERS CONTINUE RUNNING NEAR TO ABOVE NORMAL FOR MID SEPTEMBER.
SEVERAL DRY DAYS THIS WEEK WILL ENSURE THIS TREND CONTINUES. BY LATE
IN THE WEEK AND WEEKEND THERE WILL BE A THREAT FOR SHOWERS AND
THUNDERSTORMS AS A FRONT APPROACHES. IT IS TOO EARLY TO TELL HOW
MUCH RAINFALL IS POSSIBLE WITH THIS SYSTEM BUT SIGNIFICANT AMOUNTS
ARE NOT OUT OF THE QUESTION IF THE FRONT MOVES SLOWER AND ALSO
DEPENDING ON WHERE THE REMNANTS OF HURRICANE ODILE MOVE. A CLEARER
PICTURE WILL HOPEFULLY EVOLVE OVER THE NEXT COUPLE DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...MEADE
AVIATION...WDM
HYDROLOGY...HOVING
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
735 PM EDT MON SEP 15 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 325 PM EDT MON SEP 15 2014
AFTER RAIN EXITS THE AREA THIS EVENING...HIGH TEMPERATURES IN THE
MID 60S TUESDAY WILL GRADUALLY WARM INTO THE MID 70S BY SATURDAY.
DRY AND COOL OVERNIGHT CONDITIONS MAY ALLOW PATCHY FROST TO DEVELOP
WEDNESDAY NIGHT OVER CENTRAL LOWER MICHIGAN. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE BEGINNING LATE FRIDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EDT MON SEP 15 2014
MAIN CHALLENGE IN SHORT TERM IS TIMING THE EXIT OF RAIN...MOST OF
WHICH IS BEHIND THE SURFACE COLD FRONT CURRENTLY MOVING ACROSS THE
NORTHWEST FORECAST AREA. PRECIPITATION AMOUNTS UPSTREAM OVER
WISCONSIN HAVE NOT BEEN IMPRESSIVE - ONLY A FEW HUNDREDTHS IN SPOTS.
COVERAGE HOWEVER IS INCREASING AND EXPECT THIS TO CONTINUE IN THE
SHORT TERM. EXPECT A RAPID EXIT OF PRECIPITATION TO THE SOUTHEAST
THIS EVENING AND EARLY TONIGHT.
ADDED PATCHY FROST WEDNESDAY NIGHT FOR INTERIOR PORTIONS OF NORTH
CENTRAL MICHIGAN. SURFACE HIGH PRESSURE CENTERED OVER THE AREA WILL
BE FAVORABLE FOR RADIATION COOLING...BUT THIS COULD BE OFFSET BY
SOME LOW CLOUDINESS. THANKS APX FOR COORDINATION.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 325 PM EDT MON SEP 15 2014
THE PRIMARY FOCUS IS ON SHOWER AND TSTM POTENTIAL OVER THE WEEKEND
AND HOW WARM IT GETS.
STRONG WARM ADVECTION KICKS IN ON FRIDAY NIGHT IN RESPONSE TO THE
DIGGING H5 WAVE OVER THE NRN PLAINS. BEST FORCING IS CURRENTLY
PROGGED TO BE ACROSS UPR MI AND NRN LWR MI ON THE NOSE OF THE LOW
LEVEL JET... BUT CHANCE POPS ARE WARRANTED IN SW LWR MI AS THE WARM
FRONT LIFTS THROUGH.
WE SHOULD BE FIRMLY IN THE WARM SECTOR ON SATURDAY WITH MOST OF THE
CONVECTION TO OUR NORTH AND WEST. H8 TEMPS AROUND 15C AND DECENT
MIXING MAY ALLOW FOR HIGHS TOUCHING 80 DEGREES INLAND FROM LAKE
MICHIGAN. HOWEVER A FASTER COLD FRONT SOLUTION AND EARLIER ARRIVAL
OF CLOUDS/SHOWERS COULD MAKE IT DIFFICULT TO GET THAT WARM.
CURRENTLY THE SFC COLD FRONT/SHORTWAVE PASSAGE AND BEST CHANCE OF
RAIN IS PROGGED FOR SATURDAY NIGHT... FOLLOWED BY A COOL DOWN ON
SUNDAY AND MONDAY. THE NEW 12Z RUN OF THE ECMWF IS VERY AGGRESSIVE
WITH THE COLD ADVECTION NEXT MONDAY... SHOWING H8 TEMPS LESS THAN
ZERO INVADING THE STATE. THIS WOULD RESULT IN MORE IN THE WAY OF
CLOUDS AND A CHANCE OF LAKE EFFECT RAIN SHOWERS WHICH IS NOT
CURRENTLY IN THE FCST. IF THIS MODEL TREND CONTINUES THEN FUTURE
FORECASTS FOR A WEEK FROM NOW WILL NEED TO BE TRENDED MORE
PESSIMISTICALLY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 735 PM EDT MON SEP 15 2014
THE MAIN ISSUE TONIGHT IS WHAT HAPPENS WHEN THE RAIN ENDS? THE MID
CLOUDS SHOULD CLEAR FAIRLY QUICKLY AFTER THE RAIN ENDS BUT THE
SURFACE WINDS WILL BE LIGHT AND MOST AREA HAVE GOTTEN AT LEAST A
LITTLE RAIN THIS EVENING. SO THERE WOULD BE THE THREAT OF FOG
DEVELOPING OVERNIGHT. MODEL SOUNDING FROM THE RAP AND NAM SUGGEST
FOG IS POSSIBLE. THE NAMDNG5 SHOWS EXTENSIVE FOG OVER ALL OF THE
TAF SITES BY 12Z. THE ONLY PROBLEM IS WE HAVE AIR ADVECTION
TONIGHT AND THAT TYPICALLY MIXES THE DRY AIR DOWN TO THE BOTTOM OF
THE SOUNDING. SO I DID NOT PUT FOG IN THE TAFS... BUT IT MAY WELL
BE NEEDED TO BE ADDED.
OTHERWISE ONLY A FEW CUMULUS CLOUDS WITH BASES NEAR 4000 FT AGL
ARE EXPECTED TUESDAY.
&&
.MARINE...
ISSUED AT 325 PM EDT MON SEP 15 2014
NO HEADLINES ARE EXPECTED. THERE WILL BE A BRIEF UPTICK IN WAVES
OVERNIGHT WITH A SURGE OF WIND BEHIND THE COLD FRONT PASSING
THROUGH...BUT THEY SHOULD GENERALLY STAY WELL BELOW 4 FEET.
&&
.HYDROLOGY...
ISSUED AT 325 PM EDT MON SEP 15 2014
RIVERS CONTINUE RUNNING NEAR TO ABOVE NORMAL FOR MID SEPTEMBER.
SEVERAL DRY DAYS THIS WEEK WILL ENSURE THIS TREND CONTINUES. BY LATE
IN THE WEEK AND WEEKEND THERE WILL BE A THREAT FOR SHOWERS AND
THUNDERSTORMS AS A FRONT APPROACHES. IT IS TOO EARLY TO TELL HOW
MUCH RAINFALL IS POSSIBLE WITH THIS SYSTEM BUT SIGNIFICANT AMOUNTS
ARE NOT OUT OF THE QUESTION IF THE FRONT MOVES SLOWER AND ALSO
DEPENDING ON WHERE THE REMNANTS OF HURRICANE ODILE MOVE. A CLEARER
PICTURE WILL HOPEFULLY EVOLVE OVER THE NEXT COUPLE DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...MEADE
AVIATION...WDM
HYDROLOGY...HOVING
MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
653 PM EDT SUN SEP 14 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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 652 PM EDT SUN SEP 14 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
NWS MARQUETTE MI
402 PM EDT SUN SEP 14 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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 132 PM EDT SUN SEP 14 2014
EXCEPT FOR SOME MVFR CIGS AT CMX EARLY THIS AFTERNOON...UNDER
RELATIVELY DRY LOW LEVELS...MAINLY VFR CONDITIONS WILL PREVAIL AT
THE TAF SITES THROUGH THE FCST PERIOD. ROACHING COLD FRONT WILL
BRING SCT -SHRA OR SPRINKLES AT SAW EARLY THIS AFTERNOON WHERE VCSH
WAS MENTIONED. SW WINDS GUSTING TO 20 KT WILL SHIFT W BEHIND THE
FRONT THIS AFTERNOON AND MAY GUST AS HIGH AS 25 KTS AT KCMX BEFORE
TAPERING OFF TOWARD EVENING.
&&
.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...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
351 PM EDT SUN SEP 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN SEP 14 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE/PV
ANOMALY UPSTREAM OVER NRN MN. PV ADVECTION AND 290-295K ISENTROPIC
ASCENT AHEAD OF THIS FEATURE HAS PRODUCED NARROW LINE OF SHRA FROM
WRN TIP OF LAKE SUPERIOR OVER THE MN ARROWHEAD EARLY THIS MORNING.
TODAY...MODEL CONSENSUS INDICATES SHORTWAVE WILL TRACK ACROSS NRN
LAKE SUPERIOR TODAY AND THEN EXIT NE OF THE LAKE LATE THIS
AFTERNOON. PV ADVECTION...ISENTROPIC ASCENT AND LOWERING
CONDENSATION PRES DEFICITS SUGGEST MUCH OF PCPN WITH THIS SYSTEM
WILL STAY ALONG AND NORTH OF PROJECTED VORT TRACK. WILL MAINTAIN
SLIGHT CHC TO LOW CHC POPS OVER MAINLY THE NRN TIER OF UPPER MI WITH
HIGHER CHC POPS OVER LAKE SUPERIOR TODAY ALONG/AHEAD OF COLD FRONTAL
PASSAGE. EXPECT HIGH TEMPS GENERALLY IN THE UPPER 50S TO LWR 60S.
TONIGHT...WITH SHORTWAVE AND ASSOC FORCING ALREADY NE OF LAKE
SUPERIOR...EXPECT SHRA OVER ERN COUNTIES TO DIMINISH QUICKLY THIS
EVENING ALONG FRONTAL BOUNDARY. WL MAINTAIN SLIGHT CHC POPS THIS
EVENING FOR ERN COUNTIES BUT OTHERWISE EXPECT DRYING/PARTIAL
CLEARING THIS EVENING FROM THE WEST BEHIND THE FRONT. EXPECT LOW
TEMPS TO RANGE IN THE UPPER 30S OVER MUCH OF THE WRN INTERIOR AND
THE TYPICAL COLD SPOTS OF THE ERN INTERIOR TO THE MID TO UPPER 40S
NEAR THE GREAT LAKES.
.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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 132 PM EDT SUN SEP 14 2014
EXCEPT FOR SOME MVFR CIGS AT CMX EARLY THIS AFTERNOON...UNDER
RELATIVELY DRY LOW LEVELS...MAINLY VFR CONDITIONS WILL PREVAIL AT
THE TAF SITES THROUGH THE FCST PERIOD. ROACHING COLD FRONT WILL
BRING SCT -SHRA OR SPRINKLES AT SAW EARLY THIS AFTERNOON WHERE VCSH
WAS MENTIONED. SW WINDS GUSTING TO 20 KT WILL SHIFT W BEHIND THE
FRONT THIS AFTERNOON AND MAY GUST AS HIGH AS 25 KTS AT KCMX BEFORE
TAPERING OFF TOWARD EVENING.
&&
.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...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
139 PM EDT SUN SEP 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN SEP 14 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE/PV
ANOMALY UPSTREAM OVER NRN MN. PV ADVECTION AND 290-295K ISENTROPIC
ASCENT AHEAD OF THIS FEATURE HAS PRODUCED NARROW LINE OF SHRA FROM
WRN TIP OF LAKE SUPERIOR OVER THE MN ARROWHEAD EARLY THIS MORNING.
TODAY...MODEL CONSENSUS INDICATES SHORTWAVE WILL TRACK ACROSS NRN
LAKE SUPERIOR TODAY AND THEN EXIT NE OF THE LAKE LATE THIS
AFTERNOON. PV ADVECTION...ISENTROPIC ASCENT AND LOWERING
CONDENSATION PRES DEFICITS SUGGEST MUCH OF PCPN WITH THIS SYSTEM
WILL STAY ALONG AND NORTH OF PROJECTED VORT TRACK. WILL MAINTAIN
SLIGHT CHC TO LOW CHC POPS OVER MAINLY THE NRN TIER OF UPPER MI WITH
HIGHER CHC POPS OVER LAKE SUPERIOR TODAY ALONG/AHEAD OF COLD FRONTAL
PASSAGE. EXPECT HIGH TEMPS GENERALLY IN THE UPPER 50S TO LWR 60S.
TONIGHT...WITH SHORTWAVE AND ASSOC FORCING ALREADY NE OF LAKE
SUPERIOR...EXPECT SHRA OVER ERN COUNTIES TO DIMINISH QUICKLY THIS
EVENING ALONG FRONTAL BOUNDARY. WL MAINTAIN SLIGHT CHC POPS THIS
EVENING FOR ERN COUNTIES BUT OTHERWISE EXPECT DRYING/PARTIAL
CLEARING THIS EVENING FROM THE WEST BEHIND THE FRONT. EXPECT LOW
TEMPS TO RANGE IN THE UPPER 30S OVER MUCH OF THE WRN INTERIOR AND
THE TYPICAL COLD SPOTS OF THE ERN INTERIOR TO THE MID TO UPPER 40S
NEAR THE GREAT LAKES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 401 AM EDT SUN SEP 14 2014
FOR MON...A SHORTWAVE LOOKS TO MOVE INTO THE UPPER TROUGH POSITIONED
OVER THE GREAT LAKES REGION...BUT THE SHORTWAVE WILL BE BEHIND A SFC
COLD FRONT THAT WILL MOVE THROUGH ABOUT 12 HOURS AHEAD ON SUN NIGHT.
GIVEN THAT THE BEST MOISTURE WILL BE ALONG AND AHEAD OF THE FRONT AS
A 1022MB SFC HIGH OVER THE PLAINS NOSES INTO THE REGION BEHIND THE
FRONT...WIDESPREAD PRECIP IS NOT EXPECTED ON MON. COULD SEE
SCATTERED SHOWERS AS THE SHORTWAVE PASSES OR RIGHT BEHIND THE
SHORTWAVE AS THE 850MB THERMAL TROUGH PASSES...WHICH MAY PROVIDE
SOME ADDITIONAL WEAK INSTABILITY. HIGH TEMPS WILL BE IN THE 50S.
THE UPPER TROUGH INTENSIFIES AND MOVES SLOWLY E THROUGH MID WEEK AS
THE UPPER RIDGE OVER THE WRN CONUS MOVES OVER THE ROCKIES. UPPER
LEVEL ENERGY TUE THROUGH THU WILL BE MAINLY N/NE OF THE CWA...BUT
SOME LOWER LEVEL FEATURES MAY LEAD TO SOME RAIN. MODELS GENERALLY
AGREE THAT A WEAK COLD FRONT WILL MOVE IN FROM THE N/NNE TUE NIGHT
AND THEN STALL OVER THE AREA WHILE DIMINISHING WED INTO THU. BEST
CHANCES FOR PRECIP DURING THIS TIME IS TUE NIGHT INTO WED SINCE A
SFC HIGH MOVES JUST N/NE OF THE CWA WED NIGHT INTO THU...RESULTING
IN A DRIER AIRMASS. ADDITIONALLY...THERE IS POTENTIAL FOR FRONT MON
NIGHT AND WED NIGHT.
THE PATTERN BECOMES MORE PROGRESSIVE FRI INTO SAT...WHICH MAY LEAD
TO A LOW PRESSURE SYSTEM OR JUST A TROUGH MOVING IN FROM THE W ON
SAT. THERE IS DISAGREEMENT BETWEEN MODELS FOR FRI AND SAT...WHICH IS
TO BE EXPECTED GIVEN THE MORE PROGRESSIVE/TRANSITIONAL FLOW. GENERAL
CONSENSUS DOES SHOW WAA FRI INTO EARLY SAT...BRINGING A WARMER
AIRMASS WITH 850MB TEMPS OF 13C-15C. PRECIP WILL BE POSSIBLE DURING
THIS TIME GIVEN THE WAA...POSSIBLE SHORTWAVE ENERGY HINTED AT BY
MODELS...AND THE ARRIVAL OF A SFC LOW OR TROUGH. DEPENDING ON AMOUNT
OF CLEARING...MAY SEE TEMPS TOP OUT IN THE 70S IN SPOTS BOTH
DAYS...BUT WILL LEAN MORE TOWARD COOLER CONSENSUS GUIDANCE GIVEN THE
CHANCES FOR PRECIP/CLOUD COVER...WHICH HAS HIGHS IN THE MID 60S TO
70.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 132 PM EDT SUN SEP 14 2014
EXCEPT FOR SOME MVFR CIGS AT CMX EARLY THIS AFTERNOON...UNDER
RELATIVELY DRY LOW LEVELS...MAINLY VFR CONDITIONS WILL PREVAIL AT
THE TAF SITES THROUGH THE FCST PERIOD. ROACHING COLD FRONT WILL
BRING SCT -SHRA OR SPRINKLES AT SAW EARLY THIS AFTERNOON WHERE VCSH
WAS MENTIONED. SW WINDS GUSTING TO 20 KT WILL SHIFT W BEHIND THE
FRONT THIS AFTERNOON AND MAY GUST AS HIGH AS 25 KTS AT KCMX BEFORE
TAPERING OFF TOWARD EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN SEP 14 2014
A LOW PRES TROF OVER NRN MN WILL MOVE ACROSS LAKE SUPERIOR TODAY AS
S TO SW WINDS OF 10-20 KT SHIFT WEST ACROSS THE LAKE. THERE MAY BE
PERIODS OF SOMEWHAT HIGHER WINDS TO 25 KTS LATE MON NIGHT THRU EARLY
WED AHEAD OF AND BEHIND A COLD FRONT THAT WILL DROP S ACROSS LAKE
SUPERIOR TUE. LIGHTER WINDS WILL THEN BE THE RULE LATER WED THRU THU
HAS HIGH PRES MOVE SE ACROSS NRN ONTARIO TOWARD THE LOWER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
708 AM EDT SUN SEP 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN SEP 14 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE/PV
ANOMALY UPSTREAM OVER NRN MN. PV ADVECTION AND 290-295K ISENTROPIC
ASCENT AHEAD OF THIS FEATURE HAS PRODUCED NARROW LINE OF SHRA FROM
WRN TIP OF LAKE SUPERIOR OVER THE MN ARROWHEAD EARLY THIS MORNING.
TODAY...MODEL CONSENSUS INDICATES SHORTWAVE WILL TRACK ACROSS NRN
LAKE SUPERIOR TODAY AND THEN EXIT NE OF THE LAKE LATE THIS
AFTERNOON. PV ADVECTION...ISENTROPIC ASCENT AND LOWERING
CONDENSATION PRES DEFICITS SUGGEST MUCH OF PCPN WITH THIS SYSTEM
WILL STAY ALONG AND NORTH OF PROJECTED VORT TRACK. WILL MAINTAIN
SLIGHT CHC TO LOW CHC POPS OVER MAINLY THE NRN TIER OF UPPER MI WITH
HIGHER CHC POPS OVER LAKE SUPERIOR TODAY ALONG/AHEAD OF COLD FRONTAL
PASSAGE. EXPECT HIGH TEMPS GENERALLY IN THE UPPER 50S TO LWR 60S.
TONIGHT...WITH SHORTWAVE AND ASSOC FORCING ALREADY NE OF LAKE
SUPERIOR...EXPECT SHRA OVER ERN COUNTIES TO DIMINISH QUICKLY THIS
EVENING ALONG FRONTAL BOUNDARY. WL MAINTAIN SLIGHT CHC POPS THIS
EVENING FOR ERN COUNTIES BUT OTHERWISE EXPECT DRYING/PARTIAL
CLEARING THIS EVENING FROM THE WEST BEHIND THE FRONT. EXPECT LOW
TEMPS TO RANGE IN THE UPPER 30S OVER MUCH OF THE WRN INTERIOR AND
THE TYPICAL COLD SPOTS OF THE ERN INTERIOR TO THE MID TO UPPER 40S
NEAR THE GREAT LAKES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 401 AM EDT SUN SEP 14 2014
FOR MON...A SHORTWAVE LOOKS TO MOVE INTO THE UPPER TROUGH POSITIONED
OVER THE GREAT LAKES REGION...BUT THE SHORTWAVE WILL BE BEHIND A SFC
COLD FRONT THAT WILL MOVE THROUGH ABOUT 12 HOURS AHEAD ON SUN NIGHT.
GIVEN THAT THE BEST MOISTURE WILL BE ALONG AND AHEAD OF THE FRONT AS
A 1022MB SFC HIGH OVER THE PLAINS NOSES INTO THE REGION BEHIND THE
FRONT...WIDESPREAD PRECIP IS NOT EXPECTED ON MON. COULD SEE
SCATTERED SHOWERS AS THE SHORTWAVE PASSES OR RIGHT BEHIND THE
SHORTWAVE AS THE 850MB THERMAL TROUGH PASSES...WHICH MAY PROVIDE
SOME ADDITIONAL WEAK INSTABILITY. HIGH TEMPS WILL BE IN THE 50S.
THE UPPER TROUGH INTENSIFIES AND MOVES SLOWLY E THROUGH MID WEEK AS
THE UPPER RIDGE OVER THE WRN CONUS MOVES OVER THE ROCKIES. UPPER
LEVEL ENERGY TUE THROUGH THU WILL BE MAINLY N/NE OF THE CWA...BUT
SOME LOWER LEVEL FEATURES MAY LEAD TO SOME RAIN. MODELS GENERALLY
AGREE THAT A WEAK COLD FRONT WILL MOVE IN FROM THE N/NNE TUE NIGHT
AND THEN STALL OVER THE AREA WHILE DIMINISHING WED INTO THU. BEST
CHANCES FOR PRECIP DURING THIS TIME IS TUE NIGHT INTO WED SINCE A
SFC HIGH MOVES JUST N/NE OF THE CWA WED NIGHT INTO THU...RESULTING
IN A DRIER AIRMASS. ADDITIONALLY...THERE IS POTENTIAL FOR FRONT MON
NIGHT AND WED NIGHT.
THE PATTERN BECOMES MORE PROGRESSIVE FRI INTO SAT...WHICH MAY LEAD
TO A LOW PRESSURE SYSTEM OR JUST A TROUGH MOVING IN FROM THE W ON
SAT. THERE IS DISAGREEMENT BETWEEN MODELS FOR FRI AND SAT...WHICH IS
TO BE EXPECTED GIVEN THE MORE PROGRESSIVE/TRANSITIONAL FLOW. GENERAL
CONSENSUS DOES SHOW WAA FRI INTO EARLY SAT...BRINGING A WARMER
AIRMASS WITH 850MB TEMPS OF 13C-15C. PRECIP WILL BE POSSIBLE DURING
THIS TIME GIVEN THE WAA...POSSIBLE SHORTWAVE ENERGY HINTED AT BY
MODELS...AND THE ARRIVAL OF A SFC LOW OR TROUGH. DEPENDING ON AMOUNT
OF CLEARING...MAY SEE TEMPS TOP OUT IN THE 70S IN SPOTS BOTH
DAYS...BUT WILL LEAN MORE TOWARD COOLER CONSENSUS GUIDANCE GIVEN THE
CHANCES FOR PRECIP/CLOUD COVER...WHICH HAS HIGHS IN THE MID 60S TO
70.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 655 AM EDT SUN SEP 14 2014
UNDER RELATIVELY DRY LOW LEVELS...VFR CONDITIONS SHOULD PREVAIL THRU
THE FCST PERIOD AT KIWD/KCMX/KSAW. AN APPROACHING COLD FRONT SHOULD
BRING SCT -SHRA INTO NW UPPER MI BY AFTN. HAVE INCLUDED A VCSH
MENTION AT KCMX. SW WINDS GUSTING TO 20 KT WILL SHIFT W BEHIND THE
FRONT THIS AFTERNOON AND MAY GUST AS HIGH AS 25 KTS AT KCMX BEFORE
TAPERING OFF TOWARD EVENING. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN SEP 14 2014
A LOW PRES TROF OVER NRN MN WILL MOVE ACROSS LAKE SUPERIOR TODAY AS
S TO SW WINDS OF 10-20 KT SHIFT WEST ACROSS THE LAKE. THERE MAY BE
PERIODS OF SOMEWHAT HIGHER WINDS TO 25 KTS LATE MON NIGHT THRU EARLY
WED AHEAD OF AND BEHIND A COLD FRONT THAT WILL DROP S ACROSS LAKE
SUPERIOR TUE. LIGHTER WINDS WILL THEN BE THE RULE LATER WED THRU THU
HAS HIGH PRES MOVE SE ACROSS NRN ONTARIO TOWARD THE LOWER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
457 AM EDT SUN SEP 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN SEP 14 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE/PV
ANOMALY UPSTREAM OVER NRN MN. PV ADVECTION AND 290-295K ISENTROPIC
ASCENT AHEAD OF THIS FEATURE HAS PRODUCED NARROW LINE OF SHRA FROM
WRN TIP OF LAKE SUPERIOR OVER THE MN ARROWHEAD EARLY THIS MORNING.
TODAY...MODEL CONSENSUS INDICATES SHORTWAVE WILL TRACK ACROSS NRN
LAKE SUPERIOR TODAY AND THEN EXIT NE OF THE LAKE LATE THIS
AFTERNOON. PV ADVECTION...ISENTROPIC ASCENT AND LOWERING
CONDENSATION PRES DEFICITS SUGGEST MUCH OF PCPN WITH THIS SYSTEM
WILL STAY ALONG AND NORTH OF PROJECTED VORT TRACK. WILL MAINTAIN
SLIGHT CHC TO LOW CHC POPS OVER MAINLY THE NRN TIER OF UPPER MI WITH
HIGHER CHC POPS OVER LAKE SUPERIOR TODAY ALONG/AHEAD OF COLD FRONTAL
PASSAGE. EXPECT HIGH TEMPS GENERALLY IN THE UPPER 50S TO LWR 60S.
TONIGHT...WITH SHORTWAVE AND ASSOC FORCING ALREADY NE OF LAKE
SUPERIOR...EXPECT SHRA OVER ERN COUNTIES TO DIMINISH QUICKLY THIS
EVENING ALONG FRONTAL BOUNDARY. WL MAINTAIN SLIGHT CHC POPS THIS
EVENING FOR ERN COUNTIES BUT OTHERWISE EXPECT DRYING/PARTIAL
CLEARING THIS EVENING FROM THE WEST BEHIND THE FRONT. EXPECT LOW
TEMPS TO RANGE IN THE UPPER 30S OVER MUCH OF THE WRN INTERIOR AND
THE TYPICAL COLD SPOTS OF THE ERN INTERIOR TO THE MID TO UPPER 40S
NEAR THE GREAT LAKES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 401 AM EDT SUN SEP 14 2014
FOR MON...A SHORTWAVE LOOKS TO MOVE INTO THE UPPER TROUGH POSITIONED
OVER THE GREAT LAKES REGION...BUT THE SHORTWAVE WILL BE BEHIND A SFC
COLD FRONT THAT WILL MOVE THROUGH ABOUT 12 HOURS AHEAD ON SUN NIGHT.
GIVEN THAT THE BEST MOISTURE WILL BE ALONG AND AHEAD OF THE FRONT AS
A 1022MB SFC HIGH OVER THE PLAINS NOSES INTO THE REGION BEHIND THE
FRONT...WIDESPREAD PRECIP IS NOT EXPECTED ON MON. COULD SEE
SCATTERED SHOWERS AS THE SHORTWAVE PASSES OR RIGHT BEHIND THE
SHORTWAVE AS THE 850MB THERMAL TROUGH PASSES...WHICH MAY PROVIDE
SOME ADDITIONAL WEAK INSTABILITY. HIGH TEMPS WILL BE IN THE 50S.
THE UPPER TROUGH INTENSIFIES AND MOVES SLOWLY E THROUGH MID WEEK AS
THE UPPER RIDGE OVER THE WRN CONUS MOVES OVER THE ROCKIES. UPPER
LEVEL ENERGY TUE THROUGH THU WILL BE MAINLY N/NE OF THE CWA...BUT
SOME LOWER LEVEL FEATURES MAY LEAD TO SOME RAIN. MODELS GENERALLY
AGREE THAT A WEAK COLD FRONT WILL MOVE IN FROM THE N/NNE TUE NIGHT
AND THEN STALL OVER THE AREA WHILE DIMINISHING WED INTO THU. BEST
CHANCES FOR PRECIP DURING THIS TIME IS TUE NIGHT INTO WED SINCE A
SFC HIGH MOVES JUST N/NE OF THE CWA WED NIGHT INTO THU...RESULTING
IN A DRIER AIRMASS. ADDITIONALLY...THERE IS POTENTIAL FOR FRONT MON
NIGHT AND WED NIGHT.
THE PATTERN BECOMES MORE PROGRESSIVE FRI INTO SAT...WHICH MAY LEAD
TO A LOW PRESSURE SYSTEM OR JUST A TROUGH MOVING IN FROM THE W ON
SAT. THERE IS DISAGREEMENT BETWEEN MODELS FOR FRI AND SAT...WHICH IS
TO BE EXPECTED GIVEN THE MORE PROGRESSIVE/TRANSITIONAL FLOW. GENERAL
CONSENSUS DOES SHOW WAA FRI INTO EARLY SAT...BRINGING A WARMER
AIRMASS WITH 850MB TEMPS OF 13C-15C. PRECIP WILL BE POSSIBLE DURING
THIS TIME GIVEN THE WAA...POSSIBLE SHORTWAVE ENERGY HINTED AT BY
MODELS...AND THE ARRIVAL OF A SFC LOW OR TROUGH. DEPENDING ON AMOUNT
OF CLEARING...MAY SEE TEMPS TOP OUT IN THE 70S IN SPOTS BOTH
DAYS...BUT WILL LEAN MORE TOWARD COOLER CONSENSUS GUIDANCE GIVEN THE
CHANCES FOR PRECIP/CLOUD COVER...WHICH HAS HIGHS IN THE MID 60S TO
70.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 457 AM EDT SUN SEP 14 2014
UNDER RELATIVELY DRY LOW LEVELS...VFR CONDITIONS WILL PREVAIL THRU
THE FCST PERIOD AT KIWD/KCMX/KSAW. ON SUN...AN APPROACHING LOW PRES
TROF SHOULD BRING SCT -SHRA INTO NW UPPER MI BY AFTN. HAVE INCLUDED
A VCSH MENTION AT KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN SEP 14 2014
A LOW PRES TROF OVER NRN MN WILL MOVE ACROSS LAKE SUPERIOR TODAY AS
S TO SW WINDS OF 10-20 KT SHIFT WEST ACROSS THE LAKE. THERE MAY BE
PERIODS OF SOMEWHAT HIGHER WINDS TO 25 KTS LATE MON NIGHT THRU EARLY
WED AHEAD OF AND BEHIND A COLD FRONT THAT WILL DROP S ACROSS LAKE
SUPERIOR TUE. LIGHTER WINDS WILL THEN BE THE RULE LATER WED THRU THU
HAS HIGH PRES MOVE SE ACROSS NRN ONTARIO TOWARD THE LOWER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 AM EDT SUN SEP 14 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 409 PM EDT SAT SEP 13 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE VIGOROUS SHORTWAVE
THAT PRODUCED PCPN OVER MUCH OF UPPER MI LAST NIGHT NOW MOVING THRU
SRN ONTARIO INTO QUEBEC. UPSTREAM...A PAIR OF SHORTWAVES ARE
NOTED...ONE OVER ND/SRN MANITOBA AND THE OTHER OVER SRN
SASKATCHEWAN. THESE WAVES WILL BRING THE NEXT PCPN CHC TO UPPER MI
ON SUNDAY. IN THE WAKE OF LAST NIGHTS SYSTEM...850MB TEMPS ARE
CURRENTLY -1 TO -2C OVER LAKE SUPERIOR. TYPICALLY AT THIS TIME OF
YEAR...THIS WOULD BE MORE THAN SUFFICIENT FOR LAKE EFFECT CLOUDS AND
PCPN. HOWEVER...WITH A LARGE PORTION OF LAKE SUPERIOR HAVING SFC
WATER TEMPS PROBABLY ONLY AROUND 7-9C...THERE WAS NOT MUCH IN THE
WAY OF LAKE EFFECT CLOUDS EARLIER TODAY. IN FACT...THE LAKE HAS
BEHAVED MOSTLY AS STABILIZING INFLUENCE. ONE BAND WITH A FEW
SPRINKLES DID STREAM INTO ERN MARQUETTE COUNTY BRIEFLY THIS MORNING
DUE TO LAND BREEZE CONVERGENCE AND WARMER WATER TO THE S AND E OF
THE KEWEENAW. THIS AFTN...DAYTIME HEATING/LOW-LEVEL CONVERGENCE AND
MOISTURE FROM THE LAKE RESULTED IN ADDITIONAL SPRINKLES DEVELOPING
IN ERN MARQUETTE COUNTY. THESE SPRINKLES ARE DRIFTING SE THRU DELTA
AND WRN ALGER COUNTIES. WHILE LAKE EFFECT CLOUDS WERE AT A MINIMUM
EARLIER TODAY...850MB THERMAL TROF COMBINED WITH ADDED MOISTURE FROM
THE LAKE RESULTED IN WIDESPREAD CU/STRATOCU DEVELOPING OVER THE LAND
ONCE DAYTIME HEATING BEGAN.
TONIGHT...MAIN FCST CONCERN IS FROST POTENTIAL. WHILE CU/STRATOCU IS
STILL QUITE EXTENSIVE...THE DIURNAL NATURE OF THE CLOUD DEVELOPMENT
SUGGESTS THE CLOUDS WILL DISSIPATE THIS EVENING WITH THE LOSS OF
DAYTIME HEATING. MEANWHILE...LEAD SHORTWAVE TO THE W IS GENERATING A
FAIR AMOUNT OF HIGH CLOUDINESS WHICH WILL STREAM OVER THE FCST AREA
AS THE WAVE MOVES OVER THE UPPER LAKES. DISSIPATING STRATOCU THIS
EVENING BEING REPLACED BY HIGH CLOUDS WILL BE ONE FACTOR HELPING TO
KEEP TEMPS FROM CRASHING. OTHER FACTOR WILL BE DEPARTURE OF HIGH
PRES RIDGE CURRENTLY OVER THE AREA. AS PRES GRADIENT TIGHTENS BTWN
THE EXITING HIGH AND APPROACHING SFC TROF... THERE WILL BE SOME
INCREASE IN MIXING. THAT SAID...THE INITIAL DRY AIR MASS
(PRECIPITABLE WATER 45-55PCT OF NORMAL) AND LIGHT WINDS OVER THE
AREA WILL STILL ALLOW TEMPS TO FALL INTO THE MID 30S AND TO EVEN THE
LOWER 30S IN TRADITIONAL COLD SPOTS. SO...FCST WILL SHOW PATCHY
FROST OVER MUCH OF THE INTERIOR. AT THIS POINT...NOT EXPECTING
COVERAGE TO BE LARGE ENOUGH TO WARRANT A FROST ADVY. EVENING SHIFT
WILL NEED TO MONITOR CLOUD TRENDS AND TEMPS TO RE-EXAMINE THE NEED
FOR HEADLINE ISSUANCE BY LATE EVENING.
ON SUN...SECOND SHORTWAVE WILL SWING ACROSS THE UPPER GREAT LAKES.
AS IN PREVIOUS DAYS...MODELS CONTINUE TO INDICATE BEST
MOISTURE/FORCING PASSING JUST N OF THE AREA...ALONG AND N OF
PROJECTED VORT TRACK. SEE NO REASON TO DEVIATE MUCH FROM PREVIOUS
FCST WITH MAINLY CHC POPS SPREADING INTO WRN UPPER MI IN THE MID TO
LATE MORNING AND THEN REACHING THE E MID TO LATE AFTN. EXPECT HIGH
TEMPS GENERALLY IN THE UPPER 50S TO LWR 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 401 AM EDT SUN SEP 14 2014
FOR MON...A SHORTWAVE LOOKS TO MOVE INTO THE UPPER TROUGH POSITIONED
OVER THE GREAT LAKES REGION...BUT THE SHORTWAVE WILL BE BEHIND A SFC
COLD FRONT THAT WILL MOVE THROUGH ABOUT 12 HOURS AHEAD ON SUN NIGHT.
GIVEN THAT THE BEST MOISTURE WILL BE ALONG AND AHEAD OF THE FRONT AS
A 1022MB SFC HIGH OVER THE PLAINS NOSES INTO THE REGION BEHIND THE
FRONT...WIDESPREAD PRECIP IS NOT EXPECTED ON MON. COULD SEE
SCATTERED SHOWERS AS THE SHORTWAVE PASSES OR RIGHT BEHIND THE
SHORTWAVE AS THE 850MB THERMAL TROUGH PASSES...WHICH MAY PROVIDE
SOME ADDITIONAL WEAK INSTABILITY. HIGH TEMPS WILL BE IN THE 50S.
THE UPPER TROUGH INTENSIFIES AND MOVES SLOWLY E THROUGH MID WEEK AS
THE UPPER RIDGE OVER THE WRN CONUS MOVES OVER THE ROCKIES. UPPER
LEVEL ENERGY TUE THROUGH THU WILL BE MAINLY N/NE OF THE CWA...BUT
SOME LOWER LEVEL FEATURES MAY LEAD TO SOME RAIN. MODELS GENERALLY
AGREE THAT A WEAK COLD FRONT WILL MOVE IN FROM THE N/NNE TUE NIGHT
AND THEN STALL OVER THE AREA WHILE DIMINISHING WED INTO THU. BEST
CHANCES FOR PRECIP DURING THIS TIME IS TUE NIGHT INTO WED SINCE A
SFC HIGH MOVES JUST N/NE OF THE CWA WED NIGHT INTO THU...RESULTING
IN A DRIER AIRMASS. ADDITIONALLY...THERE IS POTENTIAL FOR FRONT MON
NIGHT AND WED NIGHT.
THE PATTERN BECOMES MORE PROGRESSIVE FRI INTO SAT...WHICH MAY LEAD
TO A LOW PRESSURE SYSTEM OR JUST A TROUGH MOVING IN FROM THE W ON
SAT. THERE IS DISAGREEMENT BETWEEN MODELS FOR FRI AND SAT...WHICH IS
TO BE EXPECTED GIVEN THE MORE PROGRESSIVE/TRANSITIONAL FLOW. GENERAL
CONSENSUS DOES SHOW WAA FRI INTO EARLY SAT...BRINGING A WARMER
AIRMASS WITH 850MB TEMPS OF 13C-15C. PRECIP WILL BE POSSIBLE DURING
THIS TIME GIVEN THE WAA...POSSIBLE SHORTWAVE ENERGY HINTED AT BY
MODELS...AND THE ARRIVAL OF A SFC LOW OR TROUGH. DEPENDING ON AMOUNT
OF CLEARING...MAY SEE TEMPS TOP OUT IN THE 70S IN SPOTS BOTH
DAYS...BUT WILL LEAN MORE TOWARD COOLER CONSENSUS GUIDANCE GIVEN THE
CHANCES FOR PRECIP/CLOUD COVER...WHICH HAS HIGHS IN THE MID 60S TO
70.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 715 PM EDT SAT SEP 13 2014
UNDER RELATIVELY DRY LOW LEVELS...VFR CONDITIONS WILL PREVAIL THRU
THE FCST PERIOD AT KIWD/KCMX/KSAW. ON SUN...AN APPROACHING LOW PRES
TROF SHOULD BRING SCT -SHRA INTO NW UPPER MI BY AFTN. HAVE INCLUDED
A VCSH MENTION AT KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT SAT SEP 13 2014
APPROACHING LOW PRES TROF WILL RESULT IN INCREASING S TO SW WINDS
TONIGHT INTO SUN. WHILE LOWER OBS PLATFORMS SHOULDN`T SEE WINDS
GREATER THAN THE 10-20KT RANGE...HIGH OBS PLATFORMS WILL PROBABLY
SEE GUSTS TO AROUND 25KT. WINDS SHOULD FALL BACK TO MOSTLY 10-20KT
SUN NIGHT THRU MON. THERE MAY BE SOMEWHAT HIGHER WINDS AGAIN LATE
MON NIGHT THRU EARLY WED AHEAD OF AND BEHIND A COLD FRONT THAT WILL
DROP S ACROSS LAKE SUPERIOR TUE. LIGHTER WINDS WILL THEN BE THE RULE
LATER WED THRU THU HAS HIGH PRES MOVE SE ACROSS NRN ONTARIO TOWARD
THE LOWER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
348 PM CDT SUN SEP 14 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 246 PM CDT SUN SEP 14 2014
ALTHOUGH NOWHERE NEAR AS INTERESTING ON SATELLITE AS HURRICANE ODILE
IN THE ERN PAC...WATER VAPOR IMAGERY WITH RAP H5 ANALYSIS DOES SHOW
A STRONG WAVE CURRENTLY WORKING SOUTH ACROSS MANITOBA. THIS WAVE
WILL DIVE SE ACROSS NODAK AND SRN MN TONIGHT AND ACROSS CENTRAL WI
MONDAY. THIS IS A PRETTY POTENT WAVE...WITH THE NAM SHOWING THE 1.5
PV SFC /APPROXIMATE TROPOPAUSE LEVEL/ GETTING DOWN TO H5. BESIDE THE
PV ADVECTION OUT AHEAD OF THE WAVE...A FAIRLY STRONG BAND OF FGEN
WILL BE SETTING UP ACROSS SRN MN IN THE H7-H6 LAYER.
HOWEVER...CONCURRENT WITH THIS FORCING IN THE H7-H6 LAYER IS A VERY
DRY LAYER OF AIR BETWEEN H8 AND H7 THAT RAP SOUNDINGS SHOW NOW BEING
IN PLACE ACROSS THE AREA. MAJORITY OF SHORT TERM MODELS /BOTH CAMS
AND NON-CAMS/ SHOW THIS DEFORMATION BAND SETTING UP FROM RWF TO THE
SRN TWIN CITIES METRO AND OVER TO EAU. ALTHOUGH WE HAVE THAT DRY AIR
TO WORK WITH...FORCING LOOKS TO BE AROUND LONG ENOUGH TO ALLOW LIGHT
RAIN TO FALL ALONG THE LINE MENTIONED ABOVE. MAY SEE RAIN FOR
SEVERAL HOURS TONIGHT...BUT WILL BE A STRUGGLE TO EVEN GET TO A
TENTH OF AN INCH. WHAT THIS DRY AIR WILL DO IS RESULT IN A VERY
TIGHT PRECIP GRADIENT...WITH POP FORECAST AS OF 3 PM HAVING NEAR 50
POPS DOWN TOWARD LAKEVILLE...WITH NEAR ZERO BY THE TIME YOU GET TO
ANOKA.
AFTER 6Z...A STRONGER BURST OF RAIN LOOKS TO COME INTO SW MN AND
TRACK ACROSS I-90 THROUGH 12Z AND THIS IS ASSOCIATED WITH THE PV
FEATURE MOVING THROUGH. THIS AREA OF PRECIP LOOKS TO BE A BIT MORE
EFFICIENT AT PRODUCING RAIN...SO WENT WITH AN ECMWF/GFS/HPC QPF
BLEND...WHICH RESULTED ABOUT A QUARTER INCH OF RAIN FORECAST BETWEEN
MKT AND THE IOWA BORDER TONIGHT ALONG WITH CATEGORICAL POPS.
FOR TEMPERATURES...DID BOOST LOWS SOME ACROSS SRN MN...WHERE CLOUDS
WILL LIMIT THE AMOUNT OF COOLING...BUT VERY LITTLE CHANGE WAS MADE
TO THE FORECAST TOMORROW...AS SKIES LOOK TO CLEAR OUT IN THE
MORNING...WITH A BEAUTIFUL EARLY FALL DAY ENSUING THEREAFTER WITH
HIGHS IN THE UPPER 50S TO MID 60S...CLOSE TO WHAT A BLEND OF THE
BIAS CORRECTED RAW MODEL GUIDANCE GIVES YOU.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 246 PM CDT SUN SEP 14 2014
A SURFACE HIGH BUILDS IN ACROSS THE FORECAST AREA ON MONDAY AS THE
RAIN AND CLOUD COVER MOVE OUT DURING THE AFTERNOON. A DRY AND COOL
ATMOSPHERIC COLUMN IS EXPECTED TUESDAY THROUGH THURSDAY. TUESDAY
COULD STILL BE QUITE COOL AS MN/WI REMAIN ON THE BACK SIDE OF AN
850MB COLD POCKET STRETCHING EASTWARD TOWARD THE GREAT LAKES.
THERE IS A WEAK SURFACE TROUGH AND INSTABILITY POOLING ALONG A
MOISTURE AXIS STRETCHING FROM THE SOUTHERN PLAINS INTO NORTH
CENTRAL SD TUESDAY/TUESDAY NIGHT...BUT THERE DOESN`T SEEM TO BE
MUCH CONVERGENCE AT THIS TIME AND THE BOUNDARY WOULD REMAIN WELL
SOUTHWEST OF THE AREA ANYWAY. SO...ZERO POPS IT IS TUESDAY AND
WEDNESDAY. THERE IS 925-850MB WARM ADVECTION ON WEDNESDAY AND
THURSDAY...SO THERE COULD BE A LITTLE MORE WARMING THAN WHAT IS
CURRENTLY IN THE FORECAST. WHILE MONDAY AND TUESDAY SHOULD FEATURE
PLENTY OF 60S DURING THE AFTERNOON...THERE IS THE POTENTIAL FOR
LOW 70S IN MN WEDNESDAY AND THURSDAY AFTERNOON. IT ALSO LOOKS LIKE
OVERNIGHT LOWS IN THE COMING WEEK SHOULD BE WELL ABOVE THE
FREEZING MARK...SO THERE IS VERY LITTLE THREAT OF MORNING FROST
THIS COMING WEEK.
THE NEXT CHANCE FOR PRECIP AFTER MONDAY WILL HAVE TO WAIT UNTIL AT
LEAST FRIDAY WHEN BOTH THE 14.12Z GFS/ECMWF DEPICT LIGHT QPF ACROSS
THE FORECAST AREA. THE MODELS DON`T REALLY SHOW MUCH MOISTENING BELOW
700MB BEFORE SHORTWAVE ENERGY MAKES IT INTO THE EASTERN HALF OF
MN...SO MUCH OF THE FORECAST AREA MIGHT END UP WITH VERY LIGHT RAIN
OR VIRGA DURING THE DAY ON FRIDAY /OR NOTHING/.
NONETHELESS...THERE IS GOOD LOW LEVEL SOUTHWEST FLOW AND
TEMPERATURE ADVECTION DURING THE DAY WITH A MODEST INCREASE IN
INSTABILITY...ESPECIALLY IN WESTERN AND SOUTHERN MN. THE TIMING OF
THE WAVE THROUGH THE DAY ON FRIDAY AND INTO SATURDAY IS STILL
UNCERTAIN. THE 12Z ECMWF IS FASTER THAN THE GFS...AND THE GFS ALSO
DEVELOPS A WEAK SECONDARY LOW NEAR THE COLD FRONT AND SATURDAY.
THIS WOULD PROLONG THE PRECIP WELL INTO THE
WEEKEND...HOWEVER...THE LAST 4-5 RUNS OF THE GFS HAVE REALLY
LACKED CONSISTENCY. WE ARE CARRYING CHANCE POPS FOR SHOWERS WITH
EMBEDDED THUNDER FOR NOW WITH THAT THE IDEA THAT A BROKEN BAND OF
SHOWERS WILL SWING THROUGH WITH THE COLD FRONT FRIDAY NIGHT OR
SATURDAY MORNING. IF THERE IS A LESSON TO BE LEARNED OVER THE PAST
COUPLE MONTHS...IT`S THAT THE HEAVIER SHOWERS AND MORE ROBUST
THUNDERSTORMS WILL END UP SOUTH OF THE FORECAST AREA IN IOWA AND
PORTIONS OF IL AND SOUTHERN WI...WHERE THE HIGHEST INSTABILITY IS
FORECAST TO BE LOCATED. STILL SOME TIME TO WORK THIS LATE WEEK
SYSTEM OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1249 PM CDT SUN SEP 14 2014
COLD FRONT IN THE PROCESS OF CLEARING EAU...WITH POST FRONTAL
STRATOCU SNEAKING DOWN INTO CENTRAL MN. AXN WILL HAVE AT LEAST
A COUPLE OF HOURS OF MVFR CIGS. THESE CLOUDS MAY GET AS FAR SOUTH
AS STC...BUT NOT EXPECTING THEM ANY FARTHER SOUTH THAN THAT. BIG
QUESTION FOR TONIGHT IS HOW FAR NORTH WILL PRECIP MAKE IT. THE
COMPLICATING FACTOR IS THE DRY AIR THAT WILL EXIST BELOW THE
FORCING...BUT THE RAP/HRRR/NAM SHOW SOME LIGHT RAIN GETTING UP TO
RWF/MSP/EAU. DID INTRODUCE SOME -RA TO RWF...BUT FEEL DRY AIR WILL
BE STOUT ENOUGH WITH SFC HIGH DROPPING SOUTH TO KEEP MSP/EAU TO
REPORTING VIRGA.
KMSP...BEGINNING TO SEE INDICATIONS WITH SOME OF THE SHORT TERM
MODELS THAT RAIN MAY GET AS FAR NORTH AS MSP...BUT WE WILL HAVE A
PRETTY STRONG AND DEEP LAYER OF DRY AIR BELOW THE PRECIP THAT
SHOULD ALLOW FOR NOTHING MORE THAN VIRGA. EVEN IF PRECIP DOES
REACH THE GROUND...SAID DRY AIR WILL KEEP CIGS VFR...WHILE RATES
WILL NOT BE STRONG ENOUGH TO DROP VSBYS. OTHER THAN
THAT...CONFIDENCE IS HIGH WITH THE REMAINING ASPECTS OF THE TAF.
/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...MPG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
113 PM CDT SUN SEP 14 2014
.UPDATE...
ISSUED AT 652 AM CDT SUN SEP 14 2014
DESPITE MID LEVEL CLOUDINESS IN AN AREA OF WEAK FRONTOGENESIS AND
DECENT ELEVATED INSTABILITY...ECHOES HAVE DECREASED ACROSS CHERRY
COUNTY THIS MORNING AND HAVE THEREFORE PULLED THEM FROM THE FCST.
OTHERWISE NO MAJOR CHANGES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CDT SUN SEP 14 2014
MAIN UPPER PV ANOMALY LOCATED ACROSS NRN ND WILL CONTINUE ITS QUICK
EWD PROGRESSION TO THE NRN GREAT LAKES REGION THROUGH THE DAY WHILE
ASSOCIATED FRONT LOSES SWD MOMENTUM AND IS PROGGED BY THE MODELS TO
STALL ACROSS NRN NEB. THIS IS IN LINE WITH CURRENT PRESSURE FIELDS
EARLY THIS MORNING AS BEST FALLS ARE OVER NRN MN AND WEAK RISES
BEHIND THE FRONT AS IT ENTERS THE NRN PORTION OF THE STATE. UNDULAR
BORE EVIDENT WITH THE FRONT CURRENTLY ON KLNX 88D INDICATING STABLE
LOW LEVELS...HOWEVER RAP ANALYSIS AND IR IMAGERY SUGGEST SMALL AREA
OF WEAK MID LEVEL FRONTOGENESIS INDICATIVE OF DEVELOPING WARM AIR
ADVECTION ACROSS NWRN FCST AREA CURRENTLY AND LIKELY TAPPING WEAK
INSTABILITY BASED ON CONVECTIVE NATURE TO CLOUDS...AND ECHOES
SHOWING UP ALOFT ON KLNX 88D. FOR THE REST OF THE AREA...VERY LITTLE
IN THE WAY OF CLOUDS ASSOCIATED WITH THE FRONT WHICH IS EVIDENCE OF
ITS KATABATIC NATURE WITH 0.5KM/1KM AND 700 MB VWP WINDS FROM AREA
RADARS AND RAP SHORT TERM FCST SOUNDINGS SHOWING NWRLY WINDS AHEAD
OF THE FRONT. HAVE INCLUDED SPRINKLES EARLY THIS MORNING BASED ON
RADAR TRENDS MENTIONED ABOVE.
AS UPPER PV ANOMALY AND ASSOCIATED UPPER LOW MOVES INTO NRN MN THIS
MORNING...MID AND UPPER FLOW BECOMES ZONAL ACROSS THE CENTRAL
ROCKIES AND HIGH PLAINS. IN RESPONSE...MID LEVEL WINDS BECOME SWRLY
WHICH WILL ADVECT THE EML EWD OVER THE EWD ADVANCING DRYLINE ACROSS
ERN CO...AS LOWER LEVEL WINDS BACK AND BECOME S/SERLY DURING THE
AFTERNOON. NAM PROGS SFC DEW POINTS INTO THE MID 50S ACROSS SWRN
NEB...HOWEVER THE AFOREMENTIONED EML DEVELOPS A SIGNIFICANT CAP EAST
OF THE DRYLINE IN SWRN NEB DURING THE AFTERNOON HOURS. SCT/BKN CLOUD
COVER IS EXPECTED EAST OF THE DRYLINE AS WELL WHICH WILL BE EVIDENCE
OF THE HIGHER LOW LEVEL THETA E AND HIGHER CAPE. HOWEVER...DESPITE
THE NEXT APPROACHING UPPER PV ANOMALY AND STALLED SFC BOUNDARY
ACROSS THE NRN PORTION OF THE STATE...AND THE PREVIOUSLY MENTION
HIGHER CAPE AND DECENT SHEAR...THE CAP IS EXPECTED TO BE TOO STRONG
TO ALLOW CONVECTIVE INITIATION DURING THE AFTERNOON IN WRN NEB.
HOWEVER...CONVECTION ALLOWING MODELS /CAMS/ ARE QUICKER TO DEVELOP
STORMS ACROSS NRN NEB INTO SERN SD BY EVENING WHICH WILL BE CLOSER
TO MAIN UPPER LEVEL SUPPORT AND SFC WARM FRONT SO PRECIP CHANCES
WILL BE RETAINED IN THE NERN PORTION OF THE FCST AREA...THOUGH MAY
BE PUSHED BACK IN TIME A LITTLE.
NEXT SIGNIFICANT UPPER PV ANOMALY AND ASSOCIATED UPPER LOW WILL MOVE
INTO THE NRN PLAINS THIS EVENING AND SUNDAY NIGHT. THIS WILL GIVE A
NUDGE TO THE STALLED SFC BOUNDARY AND WILL MOVE IT SWD
SOMEWHAT...BUT THE HIGH PLAINS NOCTURNAL LOW LEVEL JET WILL DEVELOP
AS DRIER AIR ACROSS THE HIGHER ELEVATIONS FURTHER WEST COOLS RAPIDLY
AFTER SUNSET...BUT ALSO PARTLY IN RESPONSE TO THE LOWERING HEIGHTS
ACROSS THE NRN PLAINS. THIS LIFT WILL BE ABLE TO TAP THE ELEVATED
INSTABILITY STILL RESIDING ACROSS SWRN NEBR TO DEVELOP THUNDERSTORMS
OVERNIGHT SUNDAY NIGHT AS THE FRONT SLOWLY CONTINUES TO SAG ACROSS
THE REMAINDER OF THE STATE. THOUGH THE NAM SUPPORTS PRECIP IN THE
SWRN PORTION OF THE STATE OVERNIGHT...CAMS FOCUS MOST OF THE PRECIP
ALONG THE COLD FRONT IN NRN NEB.
AS FOR TEMPERATURES...DESPITE DEVELOPING CLOUD COVER DURING THE
AFTERNOON IN THE SW...TEMPS WILL BE MUCH WARMER WITH INCREASING SRLY
WINDS BUT WILL BE SLIGHTLY COOLER ACROSS THE NORTH AS WINDS BECOME
ERLY NORTH OF THE WARM FRONT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN SEP 14 2014
QUASI-ZONAL UPPER TROPOSPHERIC FLOW TO PREVAIL BEHIND A PASSING
NORTHERN PLAINS WAVE EARLY IN THE EXTENDED...BUT WILL EVENTUALLY
GIVE WAY TO NORTHWESTERLY AS A WESTERN CONUS RIDGE BUILDS EAST. AS
A RESULT A GENERAL LACK OF OMEGA IS ANTICIPATED ATOP MUCH OF THE
FORECAST AREA THROUGH TUESDAY AFTERNOON...WITH THE MODELS
PROJECTING NO ATMOSPHERIC DISTURBANCES IMPACTING THE REGION.
TUESDAY EVENING INTO WEDNESDAY...THE OPERATIONAL MODELS /GFS
INITIALLY...THEN ECMWF WEDNESDAY MORNING/ GENERATES MEASURABLE QPF
ACROSS SOUTHEASTERN PORTIONS OF THE CWA...THE MODELS ARE KEYING ON
SUFFICIENT THERMAL ADVECTION/UPGLIDE IN THE 305-310K SFC FOR
PRECIPITATION PRODUCTION. DESPITE THIS...DECIDED TO LEAVE QPF OUT
OF THE FORECAST AS PROXIMITY AND BUFR SOUNDINGS SUGGEST A MOISTURE
CHALLENGED ATMOSPHERE ABOVE THE BOUNDARY LAYER WITH THE GFS
SHOWING SIGNIFICANT DRY MID LEVELS. WITH THIS IN MIND...FELT THAT
POPS WILL BE ISOLATED AT BEST IN COVERAGE WITH QPF AMOUNTS LIGHT.
IF SHOWERS/STORMS ARE TO GO...SOUTHEASTERN PORTIONS OF THE CWA
OVERNIGHT TUESDAY INTO EARLY WEDNESDAY WOULD BE THE MOST LIKELY OF
LOCATIONS. ADDITIONAL THERMAL ADVECTION INDUCED STORMS ARE SHOWN
WEDNESDAY NIGHT INTO THURSDAY...BUT MOSTLY REMOVED /SOUTH AND
EAST/ FROM OUR CWA. CR ALLBLEND PULLED ALL MENTION OF QPF OUT OF
OUR CWA DURING THIS TIME PERIOD...WHICH IS FINE FOR NOW. UPPER
PATTERN UNDERGOES A CHANGE LATE IN THE WEEK WITH THE APPROACH OF A
WESTERN CONUS TROUGH AND ATTENDANT COLD FRONT PASSAGE. THE
TROUGH/COLD FRONT WILL SUPPRESS THE RIDGE EAST OF THE FORECAST
AREA LATE WEEK AND PROVIDE FOR PRECIPITATION. THE GFS IN
COMPARISON TO THE EC REMAINS MUCH STRONGER WITH THIS LATE WEEK
TROUGH AND MORE FAVORABLE FOR WIDESPREAD SHOWERS/STORMS. THE CR
ALLBLEND PROCEDURE RAMPS UP POPS STARTING FRIDAY...WITH POPS
MAXIMIZED NEAR 40 PERCENT FOR SATURDAY AND INTO EARLY SUNDAY. TO
BE HONEST...REALLY NOT TOO KEEN ON 4 PERIODS OF QPF THAT IS
ASSOCIATED WITH THE PASSAGE OF THIS DISTURBANCE/FRONT...ESPECIALLY
IN A SOMEWHAT PROGRESSIVE PATTERN...BUT WILL LEAVE THE PROCEDURE
UNCHANGED DUE TO THE USUAL TIMING/STRENGTH DIFFERENCES SEEN THIS
FAR OUT.
DRIZZLE REPLACED THE SLIGHT CHANCE MENTION OF QPF FROM 12-15Z THIS
MONDAY AS PROXIMITY SOUNDINGS REVEAL DRYING ALOFT...BUT A SATURATED
BL WITH WEAK LIFT. THIS DRIZZLE SHOULD NOT LAST LONG AS PROXIMITY
SOUNDINGS REVEAL RAPID BL DRYING BEHIND THE FRONT. WILL ALSO NEED
TO MONITOR THE RETURN OF LOW LEVEL MOISTURE EARLY TUESDAY AS SURFACE
HIGH PRESSURE BUILDS EAST OF THE MISSOURI VALLEY. NAM12 0.5AGL RH
WOULD INDICATE A SIGHT POTENTIAL OF FOG ACROSS SOUTHWEST
NEBRASKA...BUT CONFIDENCE WAS NOT SUFFICIENT TO INCLUDE THE MENTION
WITH THIS FORECAST.
RETURN SOUTHERLY FLOW AND RESULTANT THERMAL ADVECTION WILL PROMOTE A
WARMING TREND MONDAY THROUGH MID-LATE WEEK...WIDESPREAD HIGHS IN THE
80S BY THURSDAY ARE ANTICIPATED. WARMEST READINGS WILL BE ACROSS
OUR WEST EACH DAY WITH A GREATER INFLUENCE FROM THE UPPER TROPOSPHERIC
RIDGE. OVERNIGHT LOWS WILL BENEFIT AS WELL...RISING FROM THE 40S
MONDAY MORNING...TO POSSIBLY THE 50S TO 60S BY WEEKS END.
TEMPERATURES COOL LATE WEEK BEHIND THE FRONT...BUT AT THAT...NOT
ANTICIPATING WHAT WE SAW A FEW DAYS AGO...NO FROST OR FREEZE
ISSUES ARE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 112 PM CDT SUN SEP 14 2014
TROUGH MOVING ACROSS THE AREA THIS EVENING LIKELY TO SPARK SOME
THUNDERSTORMS. FAVORABLE MODEL SOUNDINGS SUPPORT IMPACT OVERNIGHT
TO KLBF HOWEVER STILL HAVE SOME UNCERTAINTY FOR KVTN. WILL
CONTINUE THE PROB30 FOR KLBF...WITH NO MENTION YET FOR KVTN...AND
WILL MONITOR FOR POSSIBLE AMENDMENT. LATER TONIGHT...BEHIND
THUNDERSTORM ACTIVITY...EXPECT SOME STRATUS TO DEVELOP WITH MVFR
CIGS...POSSIBLY IFR. ACTIVITY WILL BE ERODE FROM THE NW AS HIGH
PRESSURE BUILDS SOUTH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SHORT TERM...JWS
LONG TERM...JACOBS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
653 AM CDT SUN SEP 14 2014
.UPDATE...
ISSUED AT 652 AM CDT SUN SEP 14 2014
DESPITE MID LEVEL CLOUDINESS IN AN AREA OF WEAK FRONTOGENESIS AND
DECENT ELEVATED INSTABILITY...ECHOES HAVE DECREASED ACROSS CHERRY
COUNTY THIS MORNING AND HAVE THEREFORE PULLED THEM FROM THE FCST.
OTHERWISE NO MAJOR CHANGES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CDT SUN SEP 14 2014
MAIN UPPER PV ANOMALY LOCATED ACROSS NRN ND WILL CONTINUE ITS QUICK
EWD PROGRESSION TO THE NRN GREAT LAKES REGION THROUGH THE DAY WHILE
ASSOCIATED FRONT LOSES SWD MOMENTUM AND IS PROGGED BY THE MODELS TO
STALL ACROSS NRN NEB. THIS IS IN LINE WITH CURRENT PRESSURE FIELDS
EARLY THIS MORNING AS BEST FALLS ARE OVER NRN MN AND WEAK RISES
BEHIND THE FRONT AS IT ENTERS THE NRN PORTION OF THE STATE. UNDULAR
BORE EVIDENT WITH THE FRONT CURRENTLY ON KLNX 88D INDICATING STABLE
LOW LEVELS...HOWEVER RAP ANALYSIS AND IR IMAGERY SUGGEST SMALL AREA
OF WEAK MID LEVEL FRONTOGENESIS INDICATIVE OF DEVELOPING WARM AIR
ADVECTION ACROSS NWRN FCST AREA CURRENTLY AND LIKELY TAPPING WEAK
INSTABILITY BASED ON CONVECTIVE NATURE TO CLOUDS...AND ECHOES
SHOWING UP ALOFT ON KLNX 88D. FOR THE REST OF THE AREA...VERY LITTLE
IN THE WAY OF CLOUDS ASSOCIATED WITH THE FRONT WHICH IS EVIDENCE OF
ITS KATABATIC NATURE WITH 0.5KM/1KM AND 700 MB VWP WINDS FROM AREA
RADARS AND RAP SHORT TERM FCST SOUNDINGS SHOWING NWRLY WINDS AHEAD
OF THE FRONT. HAVE INCLUDED SPRINKLES EARLY THIS MORNING BASED ON
RADAR TRENDS MENTIONED ABOVE.
AS UPPER PV ANOMALY AND ASSOCIATED UPPER LOW MOVES INTO NRN MN THIS
MORNING...MID AND UPPER FLOW BECOMES ZONAL ACROSS THE CENTRAL
ROCKIES AND HIGH PLAINS. IN RESPONSE...MID LEVEL WINDS BECOME SWRLY
WHICH WILL ADVECT THE EML EWD OVER THE EWD ADVANCING DRYLINE ACROSS
ERN CO...AS LOWER LEVEL WINDS BACK AND BECOME S/SERLY DURING THE
AFTERNOON. NAM PROGS SFC DEW POINTS INTO THE MID 50S ACROSS SWRN
NEB...HOWEVER THE AFOREMENTIONED EML DEVELOPS A SIGNIFICANT CAP EAST
OF THE DRYLINE IN SWRN NEB DURING THE AFTERNOON HOURS. SCT/BKN CLOUD
COVER IS EXPECTED EAST OF THE DRYLINE AS WELL WHICH WILL BE EVIDENCE
OF THE HIGHER LOW LEVEL THETA E AND HIGHER CAPE. HOWEVER...DESPITE
THE NEXT APPROACHING UPPER PV ANOMALY AND STALLED SFC BOUNDARY
ACROSS THE NRN PORTION OF THE STATE...AND THE PREVIOUSLY MENTION
HIGHER CAPE AND DECENT SHEAR...THE CAP IS EXPECTED TO BE TOO STRONG
TO ALLOW CONVECTIVE INITIATION DURING THE AFTERNOON IN WRN NEB.
HOWEVER...CONVECTION ALLOWING MODELS /CAMS/ ARE QUICKER TO DEVELOP
STORMS ACROSS NRN NEB INTO SERN SD BY EVENING WHICH WILL BE CLOSER
TO MAIN UPPER LEVEL SUPPORT AND SFC WARM FRONT SO PRECIP CHANCES
WILL BE RETAINED IN THE NERN PORTION OF THE FCST AREA...THOUGH MAY
BE PUSHED BACK IN TIME A LITTLE.
NEXT SIGNIFICANT UPPER PV ANOMALY AND ASSOCIATED UPPER LOW WILL MOVE
INTO THE NRN PLAINS THIS EVENING AND SUNDAY NIGHT. THIS WILL GIVE A
NUDGE TO THE STALLED SFC BOUNDARY AND WILL MOVE IT SWD
SOMEWHAT...BUT THE HIGH PLAINS NOCTURNAL LOW LEVEL JET WILL DEVELOP
AS DRIER AIR ACROSS THE HIGHER ELEVATIONS FURTHER WEST COOLS RAPIDLY
AFTER SUNSET...BUT ALSO PARTLY IN RESPONSE TO THE LOWERING HEIGHTS
ACROSS THE NRN PLAINS. THIS LIFT WILL BE ABLE TO TAP THE ELEVATED
INSTABILITY STILL RESIDING ACROSS SWRN NEBR TO DEVELOP THUNDERSTORMS
OVERNIGHT SUNDAY NIGHT AS THE FRONT SLOWLY CONTINUES TO SAG ACROSS
THE REMAINDER OF THE STATE. THOUGH THE NAM SUPPORTS PRECIP IN THE
SWRN PORTION OF THE STATE OVERNIGHT...CAMS FOCUS MOST OF THE PRECIP
ALONG THE COLD FRONT IN NRN NEB.
AS FOR TEMPERATURES...DESPITE DEVELOPING CLOUD COVER DURING THE
AFTERNOON IN THE SW...TEMPS WILL BE MUCH WARMER WITH INCREASING SRLY
WINDS BUT WILL BE SLIGHTLY COOLER ACROSS THE NORTH AS WINDS BECOME
ERLY NORTH OF THE WARM FRONT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN SEP 14 2014
QUASI-ZONAL UPPER TROPOSPHERIC FLOW TO PREVAIL BEHIND A PASSING
NORTHERN PLAINS WAVE EARLY IN THE EXTENDED...BUT WILL EVENTUALLY
GIVE WAY TO NORTHWESTERLY AS A WESTERN CONUS RIDGE BUILDS EAST. AS
A RESULT A GENERAL LACK OF OMEGA IS ANTICIPATED ATOP MUCH OF THE
FORECAST AREA THROUGH TUESDAY AFTERNOON...WITH THE MODELS
PROJECTING NO ATMOSPHERIC DISTURBANCES IMPACTING THE REGION.
TUESDAY EVENING INTO WEDNESDAY...THE OPERATIONAL MODELS /GFS
INITIALLY...THEN ECMWF WEDNESDAY MORNING/ GENERATES MEASURABLE QPF
ACROSS SOUTHEASTERN PORTIONS OF THE CWA...THE MODELS ARE KEYING ON
SUFFICIENT THERMAL ADVECTION/UPGLIDE IN THE 305-310K SFC FOR
PRECIPITATION PRODUCTION. DESPITE THIS...DECIDED TO LEAVE QPF OUT
OF THE FORECAST AS PROXIMITY AND BUFR SOUNDINGS SUGGEST A MOISTURE
CHALLENGED ATMOSPHERE ABOVE THE BOUNDARY LAYER WITH THE GFS
SHOWING SIGNIFICANT DRY MID LEVELS. WITH THIS IN MIND...FELT THAT
POPS WILL BE ISOLATED AT BEST IN COVERAGE WITH QPF AMOUNTS LIGHT.
IF SHOWERS/STORMS ARE TO GO...SOUTHEASTERN PORTIONS OF THE CWA
OVERNIGHT TUESDAY INTO EARLY WEDNESDAY WOULD BE THE MOST LIKELY OF
LOCATIONS. ADDITIONAL THERMAL ADVECTION INDUCED STORMS ARE SHOWN
WEDNESDAY NIGHT INTO THURSDAY...BUT MOSTLY REMOVED /SOUTH AND
EAST/ FROM OUR CWA. CR ALLBLEND PULLED ALL MENTION OF QPF OUT OF
OUR CWA DURING THIS TIME PERIOD...WHICH IS FINE FOR NOW. UPPER
PATTERN UNDERGOES A CHANGE LATE IN THE WEEK WITH THE APPROACH OF A
WESTERN CONUS TROUGH AND ATTENDANT COLD FRONT PASSAGE. THE
TROUGH/COLD FRONT WILL SUPPRESS THE RIDGE EAST OF THE FORECAST
AREA LATE WEEK AND PROVIDE FOR PRECIPITATION. THE GFS IN
COMPARISON TO THE EC REMAINS MUCH STRONGER WITH THIS LATE WEEK
TROUGH AND MORE FAVORABLE FOR WIDESPREAD SHOWERS/STORMS. THE CR
ALLBLEND PROCEDURE RAMPS UP POPS STARTING FRIDAY...WITH POPS
MAXIMIZED NEAR 40 PERCENT FOR SATURDAY AND INTO EARLY SUNDAY. TO
BE HONEST...REALLY NOT TOO KEEN ON 4 PERIODS OF QPF THAT IS
ASSOCIATED WITH THE PASSAGE OF THIS DISTURBANCE/FRONT...ESPECIALLY
IN A SOMEWHAT PROGRESSIVE PATTERN...BUT WILL LEAVE THE PROCEDURE
UNCHANGED DUE TO THE USUAL TIMING/STRENGTH DIFFERENCES SEEN THIS
FAR OUT.
DRIZZLE REPLACED THE SLIGHT CHANCE MENTION OF QPF FROM 12-15Z THIS
MONDAY AS PROXIMITY SOUNDINGS REVEAL DRYING ALOFT...BUT A SATURATED
BL WITH WEAK LIFT. THIS DRIZZLE SHOULD NOT LAST LONG AS PROXIMITY
SOUNDINGS REVEAL RAPID BL DRYING BEHIND THE FRONT. WILL ALSO NEED
TO MONITOR THE RETURN OF LOW LEVEL MOISTURE EARLY TUESDAY AS SURFACE
HIGH PRESSURE BUILDS EAST OF THE MISSOURI VALLEY. NAM12 0.5AGL RH
WOULD INDICATE A SIGHT POTENTIAL OF FOG ACROSS SOUTHWEST
NEBRASKA...BUT CONFIDENCE WAS NOT SUFFICIENT TO INCLUDE THE MENTION
WITH THIS FORECAST.
RETURN SOUTHERLY FLOW AND RESULTANT THERMAL ADVECTION WILL PROMOTE A
WARMING TREND MONDAY THROUGH MID-LATE WEEK...WIDESPREAD HIGHS IN THE
80S BY THURSDAY ARE ANTICIPATED. WARMEST READINGS WILL BE ACROSS
OUR WEST EACH DAY WITH A GREATER INFLUENCE FROM THE UPPER TROPOSPHERIC
RIDGE. OVERNIGHT LOWS WILL BENEFIT AS WELL...RISING FROM THE 40S
MONDAY MORNING...TO POSSIBLY THE 50S TO 60S BY WEEKS END.
TEMPERATURES COOL LATE WEEK BEHIND THE FRONT...BUT AT THAT...NOT
ANTICIPATING WHAT WE SAW A FEW DAYS AGO...NO FROST OR FREEZE
ISSUES ARE EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 652 AM CDT SUN SEP 14 2014
AVIATION FCST DIFFICULTY LIES WITH EXTENT OF TSRA THIS
EVE/TONIGHT ALONG COLD FRONT. HAVE LEFT IT OUT OF KVTN DUE TO
UNCERTAIN EXTENT OF DEVELOPMENT ACROSS NC NEB...THOUGH SHORT RANGE
MODELS INDICATING THERE SHOULD BE GOOD COVERAGE BUT POSSIBLY
FURTHER EAST. FOR KVTN HOWEVER WILL BE THE POTENTIAL FOR MVFR
CONDITIONS LATER TONIGHT. FURTHER S NEAR KLBF BELIEVE LLJ SHOULD
CONTRIBUTE TO DEVELOPMENT THERE AND HAVE THEREFORE LEFT A PROB30
GROUP IN. OTHERWISE VFR FOR THE MOST PATRT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SHORT TERM...JWS
LONG TERM...JACOBS
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
342 AM CDT SUN SEP 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CDT SUN SEP 14 2014
MAIN UPPER PV ANOMALY LOCATED ACROSS NRN ND WILL CONTINUE ITS QUICK
EWD PROGRESSION TO THE NRN GREAT LAKES REGION THROUGH THE DAY WHILE
ASSOCIATED FRONT LOSES SWD MOMENTUM AND IS PROGGED BY THE MODELS TO
STALL ACROSS NRN NEB. THIS IS IN LINE WITH CURRENT PRESSURE FIELDS
EARLY THIS MORNING AS BEST FALLS ARE OVER NRN MN AND WEAK RISES
BEHIND THE FRONT AS IT ENTERS THE NRN PORTION OF THE STATE. UNDULAR
BORE EVIDENT WITH THE FRONT CURRENTLY ON KLNX 88D INDICATING STABLE
LOW LEVELS...HOWEVER RAP ANALYSIS AND IR IMAGERY SUGGEST SMALL AREA
OF WEAK MID LEVEL FRONTOGENESIS INDICATIVE OF DEVELOPING WARM AIR
ADVECTION ACROSS NWRN FCST AREA CURRENTLY AND LIKELY TAPPING WEAK
INSTABILITY BASED ON CONVECTIVE NATURE TO CLOUDS...AND ECHOES
SHOWING UP ALOFT ON KLNX 88D. FOR THE REST OF THE AREA...VERY LITTLE
IN THE WAY OF CLOUDS ASSOCIATED WITH THE FRONT WHICH IS EVIDENCE OF
ITS KATABATIC NATURE WITH 0.5KM/1KM AND 700 MB VWP WINDS FROM AREA
RADARS AND RAP SHORT TERM FCST SOUNDINGS SHOWING NWRLY WINDS AHEAD
OF THE FRONT. HAVE INCLUDED SPRINKLES EARLY THIS MORNING BASED ON
RADAR TRENDS MENTIONED ABOVE.
AS UPPER PV ANOMALY AND ASSOCIATED UPPER LOW MOVES INTO NRN MN THIS
MORNING...MID AND UPPER FLOW BECOMES ZONAL ACROSS THE CENTRAL
ROCKIES AND HIGH PLAINS. IN RESPONSE...MID LEVEL WINDS BECOME SWRLY
WHICH WILL ADVECT THE EML EWD OVER THE EWD ADVANCING DRYLINE ACROSS
ERN CO...AS LOWER LEVEL WINDS BACK AND BECOME S/SERLY DURING THE
AFTERNOON. NAM PROGS SFC DEW POINTS INTO THE MID 50S ACROSS SWRN
NEB...HOWEVER THE AFOREMENTIONED EML DEVELOPS A SIGNIFICANT CAP EAST
OF THE DRYLINE IN SWRN NEB DURING THE AFTERNOON HOURS. SCT/BKN CLOUD
COVER IS EXPECTED EAST OF THE DRYLINE AS WELL WHICH WILL BE EVIDENCE
OF THE HIGHER LOW LEVEL THETA E AND HIGHER CAPE. HOWEVER...DESPITE
THE NEXT APPROACHING UPPER PV ANOMALY AND STALLED SFC BOUNDARY
ACROSS THE NRN PORTION OF THE STATE...AND THE PREVIOUSLY MENTION
HIGHER CAPE AND DECENT SHEAR...THE CAP IS EXPECTED TO BE TOO STRONG
TO ALLOW CONVECTIVE INITIATION DURING THE AFTERNOON IN WRN NEB.
HOWEVER...CONVECTION ALLOWING MODELS /CAMS/ ARE QUICKER TO DEVELOP
STORMS ACROSS NRN NEB INTO SERN SD BY EVENING WHICH WILL BE CLOSER
TO MAIN UPPER LEVEL SUPPORT AND SFC WARM FRONT SO PRECIP CHANCES
WILL BE RETAINED IN THE NERN PORTION OF THE FCST AREA...THOUGH MAY
BE PUSHED BACK IN TIME A LITTLE.
NEXT SIGNIFICANT UPPER PV ANOMALY AND ASSOCIATED UPPER LOW WILL MOVE
INTO THE NRN PLAINS THIS EVENING AND SUNDAY NIGHT. THIS WILL GIVE A
NUDGE TO THE STALLED SFC BOUNDARY AND WILL MOVE IT SWD
SOMEWHAT...BUT THE HIGH PLAINS NOCTURNAL LOW LEVEL JET WILL DEVELOP
AS DRIER AIR ACROSS THE HIGHER ELEVATIONS FURTHER WEST COOLS RAPIDLY
AFTER SUNSET...BUT ALSO PARTLY IN RESPONSE TO THE LOWERING HEIGHTS
ACROSS THE NRN PLAINS. THIS LIFT WILL BE ABLE TO TAP THE ELEVATED
INSTABILITY STILL RESIDING ACROSS SWRN NEBR TO DEVELOP THUNDERSTORMS
OVERNIGHT SUNDAY NIGHT AS THE FRONT SLOWLY CONTINUES TO SAG ACROSS
THE REMAINDER OF THE STATE. THOUGH THE NAM SUPPORTS PRECIP IN THE
SWRN PORTION OF THE STATE OVERNIGHT...CAMS FOCUS MOST OF THE PRECIP
ALONG THE COLD FRONT IN NRN NEB.
AS FOR TEMPERATURES...DESPITE DEVELOPING CLOUD COVER DURING THE
AFTERNOON IN THE SW...TEMPS WILL BE MUCH WARMER WITH INCREASING SRLY
WINDS BUT WILL BE SLIGHTLY COOLER ACROSS THE NORTH AS WINDS BECOME
ERLY NORTH OF THE WARM FRONT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 342 AM CDT SUN SEP 14 2014
QUASI-ZONAL UPPER TROPOSPHERIC FLOW TO PREVAIL BEHIND A PASSING
NORTHERN PLAINS WAVE EARLY IN THE EXTENDED...BUT WILL EVENTUALLY
GIVE WAY TO NORTHWESTERLY AS A WESTERN CONUS RIDGE BUILDS EAST. AS
A RESULT A GENERAL LACK OF OMEGA IS ANTICIPATED ATOP MUCH OF THE
FORECAST AREA THROUGH TUESDAY AFTERNOON...WITH THE MODELS
PROJECTING NO ATMOSPHERIC DISTURBANCES IMPACTING THE REGION.
TUESDAY EVENING INTO WEDNESDAY...THE OPERATIONAL MODELS /GFS
INITIALLY...THEN ECMWF WEDNESDAY MORNING/ GENERATES MEASURABLE QPF
ACROSS SOUTHEASTERN PORTIONS OF THE CWA...THE MODELS ARE KEYING ON
SUFFICIENT THERMAL ADVECTION/UPGLIDE IN THE 305-310K SFC FOR
PRECIPITATION PRODUCTION. DESPITE THIS...DECIDED TO LEAVE QPF OUT
OF THE FORECAST AS PROXIMITY AND BUFR SOUNDINGS SUGGEST A MOISTURE
CHALLENGED ATMOSPHERE ABOVE THE BOUNDARY LAYER WITH THE GFS
SHOWING SIGNIFICANT DRY MID LEVELS. WITH THIS IN MIND...FELT THAT
POPS WILL BE ISOLATED AT BEST IN COVERAGE WITH QPF AMOUNTS LIGHT.
IF SHOWERS/STORMS ARE TO GO...SOUTHEASTERN PORTIONS OF THE CWA
OVERNIGHT TUESDAY INTO EARLY WEDNESDAY WOULD BE THE MOST LIKELY OF
LOCATIONS. ADDITIONAL THERMAL ADVECTION INDUCED STORMS ARE SHOWN
WEDNESDAY NIGHT INTO THURSDAY...BUT MOSTLY REMOVED /SOUTH AND
EAST/ FROM OUR CWA. CR ALLBLEND PULLED ALL MENTION OF QPF OUT OF
OUR CWA DURING THIS TIME PERIOD...WHICH IS FINE FOR NOW. UPPER
PATTERN UNDERGOES A CHANGE LATE IN THE WEEK WITH THE APPROACH OF A
WESTERN CONUS TROUGH AND ATTENDANT COLD FRONT PASSAGE. THE
TROUGH/COLD FRONT WILL SUPPRESS THE RIDGE EAST OF THE FORECAST
AREA LATE WEEK AND PROVIDE FOR PRECIPITATION. THE GFS IN
COMPARISON TO THE EC REMAINS MUCH STRONGER WITH THIS LATE WEEK
TROUGH AND MORE FAVORABLE FOR WIDESPREAD SHOWERS/STORMS. THE CR
ALLBLEND PROCEDURE RAMPS UP POPS STARTING FRIDAY...WITH POPS
MAXIMIZED NEAR 40 PERCENT FOR SATURDAY AND INTO EARLY SUNDAY. TO
BE HONEST...REALLY NOT TOO KEEN ON 4 PERIODS OF QPF THAT IS
ASSOCIATED WITH THE PASSAGE OF THIS DISTURBANCE/FRONT...ESPECIALLY
IN A SOMEWHAT PROGRESSIVE PATTERN...BUT WILL LEAVE THE PROCEDURE
UNCHANGED DUE TO THE USUAL TIMING/STRENGTH DIFFERENCES SEEN THIS
FAR OUT.
DRIZZLE REPLACED THE SLIGHT CHANCE MENTION OF QPF FROM 12-15Z THIS
MONDAY AS PROXIMITY SOUNDINGS REVEAL DRYING ALOFT...BUT A SATURATED
BL WITH WEAK LIFT. THIS DRIZZLE SHOULD NOT LAST LONG AS PROXIMITY
SOUNDINGS REVEAL RAPID BL DRYING BEHIND THE FRONT. WILL ALSO NEED
TO MONITOR THE RETURN OF LOW LEVEL MOISTURE EARLY TUESDAY AS SURFACE
HIGH PRESSURE BUILDS EAST OF THE MISSOURI VALLEY. NAM12 0.5AGL RH
WOULD INDICATE A SIGHT POTENTIAL OF FOG ACROSS SOUTHWEST
NEBRASKA...BUT CONFIDENCE WAS NOT SUFFICIENT TO INCLUDE THE MENTION
WITH THIS FORECAST.
RETURN SOUTHERLY FLOW AND RESULTANT THERMAL ADVECTION WILL PROMOTE A
WARMING TREND MONDAY THROUGH MID-LATE WEEK...WIDESPREAD HIGHS IN THE
80S BY THURSDAY ARE ANTICIPATED. WARMEST READINGS WILL BE ACROSS
OUR WEST EACH DAY WITH A GREATER INFLUENCE FROM THE UPPER TROPOSPHERIC
RIDGE. OVERNIGHT LOWS WILL BENEFIT AS WELL...RISING FROM THE 40S
MONDAY MORNING...TO POSSIBLY THE 50S TO 60S BY WEEKS END.
TEMPERATURES COOL LATE WEEK BEHIND THE FRONT...BUT AT THAT...NOT
ANTICIPATING WHAT WE SAW A FEW DAYS AGO...NO FROST OR FREEZE
ISSUES ARE EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1230 AM CDT SUN SEP 14 2014
VISUAL FLIGHT RULES REST OF TONIGHT INTO SUNDAY AT THE KLBF AND
KVTN TERMINALS. MODELS ARE IN GOOD AGREEMENT...WHERE A WEAK
SURFACE BOUNDARY MOVES SOUTH TONIGHT THEN RETURNS NORTH ACROSS
SOUTHWEST NEBRASKA BY LATE SUNDAY AFTERNOON AS A WARM FRONT. FEW
CLOUDS WILL BE SEEN UNTIL LATE AFTERNOON AS MOISTURE SLOWLY
RETURNS ACROSS THE SOUTHWEST. ISOLATED SHOWERS AND/OR
THUNDERSTORMS MAY DEVELOP AS INSTABILITY INCREASES WITH SURFACE
HEATINGS...BUT LOW CONFIDENCE AT THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JWS
LONG TERM...JACOBS
AVIATION...KECK/JWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1105 PM EDT MON SEP 15 2014
.SYNOPSIS...A COLD FRONT APPROACHING THE REGION FROM THE WEST
TONIGHT WILL TRACK SLOWLY SOUTHWARD THROUGH THE CAROLINAS TUESDAY
INTO TUESDAY NIGHT. THE FRONT WILL GRADUALLY MOVE OFFSHORE THE
SOUTHEAST COAST ON WEDNESDAY AND THURSDAY AS HIGH PRESSURE
STRENGTHENS OVER THE GREAT LAKES AND EXTENDS SOUTHWARD THROUGH THE
MID ATLANTIC.
&&
.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM MONDAY...
OVERVIEW: CENTRAL NC IS SITUATED ON THE NORTHEAST PERIPHERY OF A
GULF COAST RIDGE...AT THE SOUTHERN FRINGE OF THE WESTERLIES IN BROAD
CYCLONIC FLOW ALOFT. 02Z WV IMAGERY AND RAP DATA INDICATED SMALL
AMPLITUDE SHORTWAVE ENERGY OVER EASTERN TN AND FAR SOUTHWESTERN NC.
PRECIPITATION: COMPACT DPVA IN THE PRESENCE OF LOW-LEVEL MOISTENING/
WARM ADVECTION AND RESULTING DESTABILIZATION ALLOWED CONVECTION TO
BLOSSOM OVER THE MOUNTAINS/FOOTHILLS BETWEEN 21-00Z. THIS ACTIVITY
HAS PERSISTED AND PROGRESSED EASTWARD TO THE YADKIN RIVER BY 03Z AND
APPEARS TO BE EITHER 1) ELEVATED OR 2) HIGH-BASED WITH CONVECTIVE
CEILINGS AT 7-10 KFT AND OBSERVATION SITES REPORTING SPRINKLES/LIGHT
RAIN WITH 7-10SM VISBYS AS PRECIP FALLS THROUGH A DRY MID-LEVEL
AIRMASS (AS SEEN ON THE 00Z GSO SOUNDING). THIS ACTIVITY WILL TRACK
EAST TOWARD THE HWY 1 CORRIDOR THROUGH 06Z IN ASSOC/W THE
APPROACHING SHORTWAVE...THOUGH IT WILL ENCOUNTER AN INCREASINGLY
UNFAVORABLE THERMODYNAMIC ENVIRONMENT AND THUS APPEARS LIKELY TO
WEAKEN WITH EASTWARD PROGRESSION. WILL INDICATE A SLIGHT TO LOW
CHANCE OF SHOWERS/SPRINKLES THROUGH 06Z WEST OF I-95...WITH THE BEST
CHANCE IN THE WESTERN PIEDMONT. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...
FOR TUE/TUE NIGHT: THE WEAK SURFACE TROUGH WILL BE IN PLACE OVER ERN
NC TUE MORNING... AND WILL EXTEND A SLIGHT CHANCE OF SHOWERS IN THE
SOUTHEAST INTO TUE TO REFLECT THE TROUGH`S PRESENCE AND THE
DEPARTING MID LEVEL WAVE. WITH SUBSEQUENT NORTHWESTERLY DOWNSLOPE
925-850 MB FLOW... WE SHOULD THEN BE FAIRLY DRY FOR SEVERAL HOURS...
UNTIL THE NEXT MID LEVEL VORTICITY MAX AND ACCOMPANYING STRONGER
SURFACE COLD FRONT APPROACH FROM THE NW BY EARLY-MID AFTERNOON.
SURFACE-925 MB LOW PRESSURE ALONG THIS FRONT WILL APPROACH FROM THE
NW AND BECOME BETTER DEFINED AS IT CROSSES THE MOUNTAINS INTO THE
PIEDMONT OF NC DURING THE AFTERNOON. MODELS SHOW A POCKET OF 6+ C/KM
MID LEVEL LAPSE RATES CROSSING SRN NC LATE TUE ALONG WITH NEGATIVE
LI VALUES. MUCAPE SHOULD PEAK AT JUST 750-1500 J/KG FOCUSED ON THE
SOUTHEAST... AND DEEP LAYER SHEAR IS MARGINAL AT ABOUT 20-25 KTS...
BUT THESE NUMBERS COMBINED WITH LOW LEVEL MASS CONVERGENCE SHOULD
STILL SUPPORT SCATTERED SHOWERS AND ISOLATED STORMS LATE TUE
AFTERNOON THROUGH TUE NIGHT. CONFIDENCE IN THE COVERAGE AND
PLACEMENT IS NOT GREAT HOWEVER... AS THERE IS LITTLE AGREEMENT IN
QPF AND POPS AMONG THE NAM/GFS/ECMWF. BUT GENERALLY EXPECT THE BEST
COVERAGE TO BE IN THE SOUTHEAST CWA... WHERE MOISTURE TRANSPORT AND
INSTABILITY WILL BE BEST... FROM LATE AFTERNOON THROUGH THE
EVENING... TAPERING DOWN TO ISOLATED SHOWERS OVERNIGHT. THICKNESSES
ADJUSTED FOR CLOUDS AND POSSIBLE SHOWERS LATE SUPPORT HIGHS FROM 82
TO 86. LOWS 60-65 TUE NIGHT AS COOLER AND DRIER AIR STARTS TO FILTER
IN POST-FRONT FROM THE NNW. -GIH
WEDNESDAY AND WEDNESDAY NIGHT...WESTERLY FLOW ALOFT WILL INDUCE
PROGRESSIVE TOP DOWN DRYING THROUGH WEDNESDAY NIGHT...LESSENING THE
DEPTH OF MOISTURE...WHILE NORTHEAST LOW LEVEL FLOW MAINTAINS
MOISTURE THROUGH ABOUT 5KFT THROUGH THURSDAY MORNING. A SHORT WAVE
WILL BE MOVING ACROSS THE SOUTHERN PERIPHERY OF THE AREA ON
WEDNESDAY...ACCOMPANIED BY AN H85 WAVE THAT WILL ENHANCE LIFT VIA
CONVERGENCE AND WEAK ISENTROPIC LIFT AT THE TOP OF THE MOISTURE
COLUMN. HENCE WILL MAINTAIN A CHANCE POP FOR SHOWERS ACROSS THE
SOUTH AND A SLIGHT CHANCE ACROSS THE NORTH THROUGH WEDNESDAY...
DIMINISHING TO A LINGERING SLIGHT CHANCE IN THE EAST INTO THURSDAY.
COOL AIR ADVECTION WILL COMMENCE LATE DAY AS THE SHORT WAVE PASSES
AND WITH THE DAMPNESS AND CHANCE OF SHOWERS...HIGHS WEDNESDAY WILL
RANGE FROM 75 TO 80...WITH SOME LOWER 70S POSSIBLE ACROSS THE
NORTHEAST WHERE COOL AIR WILL ARRIVE A LITTLE SOONER. LOWS WEDNESDAY
NIGHT WILL BE MAINLY IN THE UPPER 50S. -MLM
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...
A LONG WAVE TROF SETS UP ACROSS THE EASTERN CONUS BY LATE WEEK...
CONCURRENT WITH STRONG HIGH PRESSURE BUILDING INTO EASTERN CANADA
AND DOWN THE EAST COAST ON FRIDAY WITH THE RESULTING DAMMING
SCENARIO LINGERING THROUGH THE WEEKEND. LOW AMPLITUDE MID LEVEL
RIDGING SHOULD INHIBIT PRECIP CHANCES THROUGH THE WEEKEND...WHILE
THE PROLONGED EAST TO NORTHEAST LOW LEVEL FLOW OFF THE ATLANTIC WILL
SUPPRESSES HIGH TEMPS INTO THE LOW AND MID 70S THROUGH SATURDAY.
A STRONG TROF MOVING ACROSS THE MIDWEST WILL NUDGE THE SURFACE HIGH
FURTHER OFFSHORE. THE WEAKENED FLOW WILL ALLOW THE AIRMASS TO
MODERATE ON SUNDAY...WITH HIGHS MOSTLY IN THE UPPER 70S. FLOW VEERS
TO SOUTHWEST BY MONDAY AHEAD OF THE UPPER TROF AND SURFACE
FRONT...WITH INCREASING MOISTURE IN THE RESULTING RETURN FLOW AND A
CHANCE OF SHOWERS BY LATE DAY MONDAY. HIGHS MONDAY WILL BE WITHIN A
DEGREE OR TWO OF 80. MORNING LOWS THROUGH THE PERIOD WILL BE MOSTLY
FROM 55 TO 60 DEGREES. -MLM
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 750 PM MONDAY...
24 HOUR TAF PERIOD: MVFR CONDITIONS HAVE HELD ON AT MOST LOCATIONS
THIS EVENING AND WILL CONTINUE TO DO SO OVERNIGHT TONIGHT WITH THE
POSSIBILITY OF IFR/LIFR CEILINGS DURING THE OVERNIGHT HOURS AND JUST
BEFORE SUNRISE. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT AS A WEAK
SHORTWAVE CROSSES THE AREA FROM THE WEST. A FEW SPRINKLES CANT BE
RULED OUT..ESPECIALLY IN THE TRIAD. CONDITIONS SHOULD GRADUALLY
IMPROVE TO VFR AS MOISTURE DECREASES ON TUESDAY WITH SOME CLOUDS IN
THE 3-5 KFT LAYER. THERE WILL BE A SLIGHT CHANCE FOR RAIN OR
ISOLATED THUNDER IN THE SOUTH AND EAST LATE TUESDAY AFTERNOON INTO
THE EVENING HOURS.
LONG TERM: A GENERALLY DRIER PERIOD WILL ROUND OUT THE END OF THE
WEEK WITH SLIGHT CHANCES FOR SOME AFTERNOON SHOWERS WEDNESDAY BUT
GENERALLY VFR CONDITIONS PREVAILING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...HARTFIELD/MLM
LONG TERM...MLM
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1021 PM EDT MON SEP 15 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE EARLY TUESDAY MORNING. HIGH PRESSURE
WILL RIDGE DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...THE NCEP PARALLEL VERSION OF THE HRRR HAS AN
EXCELLENT HANDLE ON OBSERVED RADAR ECHOES AND EVEN HAS PICKED UP ON
THE MESOSCALE LANDBREEZE WINDS OBSERVED NEAR THE BEACHES THIS
EVENING. BASED ON ITS EXCELLENT HANDLING OF ACTIVITY SO FAR I HAVE
BLENDED ITS 23Z RUN INTO MOST SENSIBLE FORECAST GRIDS OVERNIGHT. THE
BEST POTENTIAL FOR MEASURABLE RAIN OVERNIGHT WILL EXIST FOR THE NEXT
FEW HOURS NEAR THE SANTEE RIVER AND ALONG THE SOUTH CAROLINA COAST.
THIS ACTIVITY WILL PROBABLY THIN OUT AFTER MIDNIGHT...BUT AS THE 500
MB TROUGH APPROACHES OUR LONGITUDE LATE TONIGHT SHOWER COVERAGE MAY
INCREASE AGAIN ACROSS SOUTHEAST NORTH CAROLINA AND THE SC COAST. NO
CHANGES ARE NEEDED TO FORECAST LOWS WHICH RANGE FROM THE UPPER 60S
INLAND TO AROUND 70 AT THE BEACHES. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...
ONLY TWO CHANGES HAVE BEEN MADE TO THE FORECAST WITH THIS EARLY
EVENING UPDATE. FORECAST LOW TEMPERATURES HAVE BEEN RAISED BY
SEVERAL DEGREES BASED ON THE EXPECTATION CLOUD COVER WILL IMPEDE
RADIATIONAL COOLING OVERNIGHT. INCREASING LOW-LEVEL WINDS WILL ALSO
HELP TO KEEP THE BOUNDARY LAYER MIXED WITH ONLY A WEAK NOCTURNAL
INVERSION EXPECTED. RADAR SHOWS AN AREA OF RAIN WITH EMBEDDED
THUNDERSTORMS CROSSING THE SANTEE RIVER HEADING TOWARD GEORGETOWN.
POPS HAVE BEEN RAISED SUBSTANTIALLY ACROSS GEORGETOWN COUNTY FOR THE
NEXT COUPLE OF HOURS...BUT LATEST MODELS SHOW PRECIP CHANCES FOR THE
REMAINDER OF THE FORECAST AREA ARE QUITE LOW OVERNIGHT. PREVIOUS
DISCUSSION FROM 300 PM FOLLOWS...
THICK CLOUDS HAVE KEPT AFTERNOON TEMPS BELOW NORMAL. THESE CLOUDS
ARE EXPECTED TO HANG ON THROUGH THE NIGHT GIVEN PLENTIFUL LOW LEVEL
MOISTURE WITH CEILINGS LOWERING AS THE COLUMN COOLS AND STABILIZES.
A WEAK MID-LEVEL SHORTWAVE AND SURFACE REFLECTION WILL REACH THE
EASTERN CAROLINAS FROM THE WEST OVERNIGHT. THESE FEATURES MAY
PROVIDE JUST ENOUGH CONVERGENCE TO GENERATE ISOLATED TO SCATTERED
SHOWERS AND THUS WILL HAVE TO KEEP SMALL POPS IN THE FORECAST
THROUGH SUNRISE TUE. WE DO NOT EXPECT ANY OF THE PRECIPITATION TO BE
HEAVY GIVEN THE DIMINISHING DEPTH OF DEEPER MOISTURE AND THE LACK OF
INSTABILITY.
A RATHER FLAT DIURNAL CURVE IS EXPECTED WITH NIGHTTIME VALUES ONLY
ABOUT 10 DEGREES BELOW THE HIGHS ACHIEVED THIS AFTERNOON. DESPITE
THE CLOUDS...WE ARE GENERALLY FORECASTING MINIMUMS TO BE NEAR OR
JUST BELOW THE COOLEST OF GUIDANCE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...A LINGERING FRONT THAT WAS SOUTH OF AREA
WILL MOVE BACK INTO THE AREA. A MINOR PERTURBATION IN THE MID TO
UPPER LEVELS WILL MOVE THROUGH EARLY TUES HELPING TO ENHANCE
CONVECTION ALONG THE FRONT. LOOKS LIKE THE FRONT WILL CONTINUE TO
MOVE SLOWLY NORTHWARD THROUGH TUES AS A COLD FRONT MOVES DOWN FROM
THE NORTHWEST. A PRE FRONTAL TROUGH SHOULD MERGE WITH THIS SYSTEM
AND MODELS CONTINUE TO SHOW WEAK LOW PRESSURE DEVELOPING ALONG
THIS SYSTEM ALONG THE SC COAST THROUGH TUES NIGHT INTO WED BEFORE
AMPLIFYING MID TO UPPER TROUGH FINALLY PUSHES THE WHOLE SYSTEM OFF
SHORE. THE HIGHEST PCP WATER VALUES WILL CREEP BACK NORTH THROUGH
TUES MORNING REMAINING OVER EASTERN CAROLINAS BEFORE GETTING
PUSHED OFF SHORE. THEREFORE SHOULD SEE DECENT CONVECTIVE ACTIVITY
THROUGH AT LEAST EARLY TUES AS WAVE OF LOW PRESSURE DEVELOPS ALONG
LINGERING FRONT WHILE ANOTHER COLD FRONT MOVES IN FROM THE
NORTHWEST. PCP WATER VALUES UP ABOVE 2 INCHES ON TUES WILL
DECREASE SLOWLY TO 1.5 INCHES BY WED AND DOWN TO 1.3 INCHES BY
EARLY THURS MORNING AS MID TO UPPER TROUGH SHIFTS EAST WITH DEEPER
DRIER NW FLOW DEVELOPING. LOW LEVEL MOISTURE BELOW 5K FT WILL
PERSIST AND THEREFORE EXPECT PLENTY OF CLOUDS THROUGH MOST OF THE
PERIOD. SOME DRIER AIR DOES MAKE IT INTO AREA IN W-NW LOW LEVEL
FLOW IN THE LOW TO MID LEVELS BY TUES AFTN AND THEREFORE MAY SEE
SOME SUNSHINE ACROSS INLAND AREAS THROUGH THE DAY ON TUES. THE BEST
CHC OF HEAVIER SHWRS/TSTMS WILL EXIST ON TUES...BUT LINGERING
MOISTURE WILL KEEP CLOUDS AND SOME PCP IN THE AREA THROUGH WED.
TEMPERATURES MAY BE A BIT TRICKY ON TUES. SHOULD REACH INTO THE
MID 80S AS WINDS SHIFT SOUTH OVER PORTIONS OF THE AREA AND IN
PLACES THAT SEE SOME BRIGHTENING OF SKIES TUES AFTN. TEMPS WILL BE
LOWER ON WED AS COOLER AIR MAKES ITS WAY IN BEHIND FRONT. OVERNIGHT
LOWS WILL RUN ABOVE NORMAL WITH CLOUDS BLANKETING THE AREA MOST OF
THE TIME.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...MID LEVEL TROUGH OVER THE EAST COAST AT THE
START OF THE PERIOD WILL SHIFT NORTHEAST AS MID LEVEL RIDGE OVER
THE WESTERN GULF COAST EXPANDS EAST. DEVELOPMENT OF PROGRESSIVE
FLOW OVER NEW ENGLAND FRI WILL HELP PUSH SURFACE HIGH RIDGING DOWN
THE COAST THU/FRI OFF THE COAST FOR THE WEEKEND. THIS WILL BRING
AN END TO LOW CLOUDS...BELOW CLIMO TEMPERATURES...AND THE THREAT
OF PRECIP FOR SAT AND SUN.
WEAK MID LEVEL RIDGING OVER THE REGION COMBINED WITH ELONGATED
SURFACE HIGH OVER THE CENTRAL CAROLINAS WILL CLEAR SKIES AND BRING
ABOUT A RETURN TO SEASONABLE CONDITIONS FOR THE WEEKEND. ANOTHER
COLD FRONT...PUSHED BY A STRONG MID LEVEL TROUGH...WILL MOVE ACROSS
THE AREA ON MON. FROPA TIMING STILL SOMEWHAT UNCERTAIN AS IT COULD
BE ANYWHERE FROM MON MORNING TO MON EVENING. LIFT ALONG THE FRONT
AND NARROW BAND OF MOISTURE SHOULD KICK OFF SOME SHOWERS REGARDLESS
OF TIMING. IF THE FRONT ARRIVES LATER AND DIURNAL INSTABILITY IS
ABLE TO DEVELOP COVERAGE WOULD BE INCREASED...AS WOULD THE POTENTIAL
FOR THUNDER. FOR NOW FAVOR THE SLOWER SOLUTION GIVEN THE TENDENCY
FOR MID LEVEL RIDGING TO HOLD ON LONGER THAN EXPECTED.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...SATELLITE IMAGERY SHOWS A FEW MORE BREAKS IN THE LOW
CLOUDS AS COMPARED TO YESTERDAY...AND CONDITIONS COULD BRIEFLY
IMPROVE TO VFR THIS EVENING. BUT CIGS ARE EXPECTED TO FILL BACK IN
AND LOWER TO MVFR/IFR OVERNIGHT AS COOL MOIST AIR LINGERS OVER OUR
AREA. THE HRRR...SREF PROBS AND MODEL SOUNDINGS AGREE THAT CIGS AT
KFLO/KLBT WILL DROP TO IFR/LIFR LEVELS AFTER 08Z AND PERSIST THRU
DAYBREAK. COULD ALSO SEE REDUCED VSBYS OVERNIGHT AS WINDS GO CALM.
MVFR CIGS WILL LIKELY PREVAIL AT THE COASTAL TERMINALS EARLY TUE...
AS ANY IFR THAT DEVELOPS ALONG THE COAST WOULD BE BRIEF AND MORE
TEMPO IN NATURE. HAVE ALSO INCLUDED VCSH FOR KILM/KCRE/KMYR EARLY
TUE AS DEEP MOISTURE RETURNS WITH A REMNANT FRONT LIFTING NORTHWARD
AS WELL AS A WEAK UPPER DISTURBANCE. ANY SHOWERS THAT DEVELOP COULD
PRODUCE BRIEF/LOCALIZED PERIODS OF IFR OVER A COASTAL TAF SITE. MVFR
CIGS MAY LINGER THROUGH THE MORNING...BUT EXPECT VFR DURING THE AFTN
HOURS AS LIGHT N-NW WINDS BECOME SOUTHEAST AOB 10 KT AHEAD OF AN
APPROACHING COLD FRONT.
EXTENDED OUTLOOK...POST-FRONTAL MVFR CIGS MAY DEVELOP WED AS COOLER
AIR WEDGES INTO THE REGION. EARLY MORNING MVFR/IFR CIGS POSSIBLE ON
THU. GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...A LANDBREEZE HAS DEVELOPED OVER THE PAST FEW
HOURS AS INLAND AIR TEMPERATURES HAVE FALLEN INTO THE LOWER 70S BUT
OFFSHORE AIR TEMPERATURES REMAIN IN THE UPPER 70S. THE LIGHT
EASTERLY SYNOPTIC WINDS WERE NOT ENOUGH TO KEEP THIS LANDBREEZE
PINNED TO THE BEACHES AND EVEN RADAR SEES THE LEADING EDGE OF THIS
COOLER AIR 10 MILES OFF THE COAST AND SPREADING SOUTHWARD. THIS
MESOSCALE WIND CIRCULATION IS GOING TO OVERWHELM THE SYNOPTIC WIND
FOR AT LEAST THE NEXT SEVERAL HOURS UNTIL THE COLD FRONT APPROACHES
LATE TONIGHT. THE 23Z NCEP PARALLEL VERSION OF THE HRRR CAPTURED
THIS EFFECT QUITE WELL...AND WAS USED AS THE BASIS FOR THE FORECAST
UPDATE THIS EVENING. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
PREVIOUS FORECAST IS IN PRETTY GOOD SHAPE. THE ONLY CHANGES WERE TO
BACK WINDS AROUND MORE EAST TO NORTHEASTERLY EARLY THIS EVENING
BASED ON CURRENT OBSERVATIONS ALONG THE COAST. WIND DIRECTIONS
SHOULD VEER OFFSHORE EARLY TUESDAY MORNING AS PREVIOUSLY EXPECTED.
RADAR SHOWS AN AREA OF RAIN AND EMBEDDED T-STORMS JUST WEST OF
GEORGETOWN WHICH SHOULD AFFECT THE WATERS MAINLY SOUTH OF MYRTLE
BEACH OVER THE NEXT FEW HOURS. PREVIOUS DISCUSSION FROM 300 PM
FOLLOWS...
EASTERLY WINDS THROUGH THIS EVE WILL VEER AS
HIGH PRESSURE REORIENTS AND A TROUGH REACHES THE AREA TUE MORNING.
WINDS SHOULD TURN TO SOUTHERLY LATER THIS EVE AND THEN ALL THE WAY
AROUND TO A WNW DIRECTION BY MORNING. WIND SPEEDS WILL BE 10 KT OR
LESS THROUGH THE NIGHT. SEAS WILL GENERALLY BE 2 FT OR LESS. SEAS
WILL BUILD ON TUE AS SWELL FROM DISTANT HURRICANE EDOUARD BEGIN TO
REACH THE AREA.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...WINDS WILL BE VARIABLE ON TUES AS A WAVE OF
LOW PRESSURE DEVELOPS ALONG LINGERING FRONT TO THE SOUTH AS IT MAKES
ITS WAY BACK NORTH. AT THE SAME TIME A COLD FRONT WILL MOVE IN
FROM THE NORTHWEST. EVENTUALLY WINDS WILL TAKE ON A MORE
NORTHERLY FLOW. OVERALL WINDS WILL REMAIN LIGHT AND VARIABLE WITH
SEAS HOLDING BELOW 3 FT TUES. AS WINDS SHIFT TO THE E-NE THROUGH
WED EXPECT AN INCREASE UP TO 10 TO 15 KTS. THIS WILL COMBINE WITH
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 ON WED. THE LONGER PERIOD
EASTERLY SWELLS FROM EDOUARD WELL OUT IN THE ATLANTIC WATERS WILL
BEGIN TO ENTER THE LOCAL WATERS TUES AFTN PEAKING AROUND 16
SECONDS OVERNIGHT TUES.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...A COMBINATION OF SCEC AND SCA HEADLINES WILL
LIKELY BE REQUIRED FOR MUCH IF NOT ALL OF THE PERIOD. HIGH
PRESSURE BUILDING DOWN THE COAST THU AND FRI WILL MAINTAIN PINCHED
GRADIENT WITH SPEEDS APPROACHING 20 KT AT TIMES. GRADIENT STARTS
TO RELAX A LITTLE SAT AS HIGH ELONGATES. HOWEVER...NORTHEAST FLOW
WILL REMAIN A SOLID 15 KT THROUGH THE END OF THE PERIOD. SEAS 3 TO
5 FT AT THE START OF THE PERIOD WILL BUILD TO 4 TO 7 FT THU NIGHT
OR FRI...MAINLY IN WATERS EXPOSED TO PROLONGED NORTHEAST FLOW.
SHELTERED WATERS MAY SEE AS LOW AS 2 FT. SEAS THU WILL BE A
COMBINATION OF THE BUILDING WIND WAVE AND SWELL FROM EDOUARD. SEAS
FRI AND SAT WILL BE WIND WAVE DOMINATED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...RGZ
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1212 AM CDT SUN SEP 14 2014
.UPDATE...
ISSUED AT 1209 AM CDT SUN SEP 14 2014
MADE ONLY MINOR ADJUSTMENTS TO THE FORECAST FOR THIS UPDATE. EARLY
MORNING 11-3.9 MICRON SATELLITE IMAGERY SHOWS STRATUS MOVING
SOUTHEAST INTO NORTH CENTRAL NORTH DAKOTA. THE 14.00Z NAM SUGGESTS
THE CLOUDS MAY LINGER A BIT LONGER TODAY (SUNDAY) IN THE NORTHEAST
PORTION OF THE FORECAST AREA...SO STARTED THAT TREND IN THIS
UPDATE. THE FROST ADVISORY STILL LOOKS GOOD SO LEFT IT IN PLACE.
UPDATE ISSUED AT 951 PM CDT SAT SEP 13 2014
NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE. DECIDED TO NOT
EXPAND THE FROST ADVISORY AS THE LOWEST DEW POINTS IN THE MID 30S
AS OF 0230 UTC RESIDE WITHIN THE CURRENT ADVISORY...WITH WINDS
EXPECTED TO BECOME CALM AS THE SURFACE RIDGE AXIS PROPAGATES INTO
WESTERN NORTH DAKOTA. ELSEWHERE OUTSIDE OF THE
ADVISORY...RELATIVELY GREATER LOW LEVEL MOISTURE...STRONGER WINDS
AND GREATER CLOUD COVER SHOULD KEEP TEMPERATURES WARM ENOUGH TO
PREVENT WIDESPREAD FROST.
UPDATE ISSUED AT 652 PM CDT SAT SEP 13 2014
NO CHANGES PLANNED AT THIS TIME IN REGARDS TO THE FROST ADVISORY
FOR TONIGHT...WHICH IS IN LINE WITH THE 18 UTC NAM/GFS/MAV. WILL
CONTINUE TO MONITOR CLOUD TRENDS THROUGH EVENING SHOULD A SMALL
EXPANSION OF THE ADVISORY BE NECESSARY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 329 PM CDT SAT SEP 13 2014
COLD FRONT MOVING THROUGH THE REGION WILL GENERATE WIDELY
SCATTERED SHOWERS ACROSS NORTHERN NORTH DAKOTA THIS AFTERNOON AND
EARLY THIS EVENING. GENERALLY FOLLOWED THE HRRR IN AREA AND TIMING
OF THE SHOWERS. SHOWERS WILL END BEFORE MIDNIGHT. SKIES WILL CLEAR
WITH OVERNIGHT LOWS IN THE LOWER TO MIDDLE 30S WEST. ISSUED A
FROST ADVISORY ACROSS THE WEST...GENERALLY WEST OF THE MISSOURI
RIVER AND WEST OF MINOT. SURFACE HIGH PRESSURE WILL COVER THE
REGION SUNDAY AND ANOTHER ROUND OF PATCH FROST IS POSSIBLE SUNDAY
NIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 329 PM CDT SAT SEP 13 2014
THE EXTENDED PERIOD WILL REMAIN LARGELY DRY THROUGH THURSDAY AS A
LARGE UPPER LOW ACROSS EASTERN CANADA SLOWLY MOVES EAST. AS THIS
HAPPENS BROAD RIDGING WILL DEVELOP OVER THE CENTRAL AND NORTHERN
PLAINS. THIS WILL ALLOW A SLOW WARMING TREND THROUGH THE MIDDLE TO
AND OF NEXT WEEK. BY NEXT WEEKEND A COLD FRONT WILL MOVE THROUGH
BRINGING SCATTERED THUNDERSTORMS TO THE REGION THURSDAY NIGHT INTO
FRIDAY NIGHT.
FOR TEMPERATURES...SUNDAY NIGHT COULD SEE SOME SCATTERED FROST
BEFORE THE WARM UP BEGINS. OTHER THAN THAT...MORNING LOWS WILL B IN
THE 40S TO MIDDLE 50S WITH HIGHS IN THE 60S MONDAY AND THE 70S TO
AROUND 80 TUESDAY THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1209 AM CDT SUN SEP 14 2014
MVFR CEILINGS ARE POSSIBLE AT KMOT EARLY THIS SUNDAY MORNING AS
THEY PIVOT IN BEHIND A DEPARTING AREA OF SURFACE LOW PRESSURE.
WILL KEEP THE OTHER TERMINAL LOCATIONS VFR...THOUGH KJMS WILL HAVE
TO BE MONITORED SINCE IT APPEARS THE MVFR STRATUS MAY APPROACH
THAT AREA LATER TODAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NDZ001-
002-009-010-017>021-031>034-040>045.
&&
$$
UPDATE...CK
SHORT TERM...WAA
LONG TERM...WAA
AVIATION...CK
AREA FORECAST DISCUSSION
NWS NORMAN OK
851 PM CDT MON SEP 15 2014
.UPDATE...
HAVE MADE SOME MINOR CHANGES TO THE GRIDS FOR TONIGHT. BASED ON
LATEST COUPLE OF RUNS OF THE HRRR WILL KEEP LOWER END CHANCE POPS
ACROSS PORTIONS OF CENTRAL INTO SOUTHEAST OKLAHOMA THIS EVENING
AND THEN A BIT HIGHER ACROSS SOUTHERN OK INTO NORTH TEXAS LATE
TONIGHT AS SFC FRONT WORKS SOUTH TOWARD THE RED RIVER.
&&
.PREV DISCUSSION... /ISSUED 638 PM CDT MON SEP 15 2014/
AVIATION...
A COLD FRONT IS SLOWLY MOVING SOUTHWARD...AND WILL RESULT IN A
NORTHERLY WIND SHIFT AT ALL TERMINALS BY 12Z TUES. IN THE WAKE OF
THIS FRONT...EXPECT MVFR/IFR CIGS TO DEVELOP...FIRST FROM
KGAG/KWWR TO KPNC...THEN SOUTHWARD OVERNIGHT. SPORADIC SHRA MAY
LINGER IN THE VICINITY OF THE FRONT...BUT CONFIDENCE IS TOO LOW TO
MENTION IN TAFS. MORE WIDESPREAD SHRA/TSRA MAY DEVELOP FROM 15Z TO
20Z TUES...POTENTIALLY AFFECTING KSPS...WHERE PROB30 WILL BE
MAINTAINED. LOW CIGS WILL BE SLOW TO ERODE...BUT SHOULD GENERALLY
CLEAR BY 18Z TO 20Z MOST TERMINALS WITH VFR AND RETURNING
SOUTHERLY WINDS.
PREV DISCUSSION... /ISSUED 315 PM CDT MON SEP 15 2014/
DISCUSSION...
A COLD FRONT THAT IS NOW ENTERING FAR NORTHWEST OKLAHOMA WILL
CONTINUE TO ADVANCE SOUTHEAST OVERNIGHT. MODELS...SATELLITE...AND
RADAR SUGGEST SCATTERED SHOWERS/THUNDERSTORMS NEAR THE FRONT...AND
A FEW PATCHES OF RAIN ELSEWHERE THIS AFTERNOON INTO THE EVENING
AND OVERNIGHT PERIOD.
RAIN CHANCES CONTINUE THROUGH MUCH OF THE WEEK AS VARIOUS WEAK
FEATURES MOVE THROUGH THE SOUTHERN PLAINS AND THE RATHER MOIST
ATMOSPHERE IN PLACE. A GREATER CHANCE FOR RAIN WILL COME THIS
WEEKEND AS ANOTHER COLD FRONT ARRIVES.
MOISTURE FROM HURRICANE ODILE MAY BE PULLED INTO THE LARGE-SCALE
CIRCULATION OVER OKLAHOMA AND NORTHWEST TEXAS THIS WEEKEND. IF
THIS HAPPENS...THE AMOUNT OF RAINFALL THAT OCCURS WILL BE
ENHANCED SIGNIFICANTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 64 82 66 87 / 30 20 10 20
HOBART OK 65 85 67 89 / 20 20 10 10
WICHITA FALLS TX 68 86 69 89 / 30 40 10 20
GAGE OK 59 83 64 90 / 20 10 10 10
PONCA CITY OK 61 79 63 86 / 20 10 20 30
DURANT OK 68 87 69 88 / 30 30 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/84
AREA FORECAST DISCUSSION
NWS PENDLETON OR
445 PM PDT MON SEP 15 2014
UPDATED FOR AVIATION DISCUSSION
.SHORT TERM...TONIGHT THROUGH THURSDAY...HIGH PRESSURE WILL CONTINUE
OVER THE REGION OVERNIGHT AND TUESDAY WITH A LONG WAVE TROUGH OVER
THE EASTERN PACIFIC. A SMALL AND WEAK DISTURBANCE MOVING OUT OF THE
TROUGH AND UP THE WEST SIDE OF THE RIDGE WILL PRODUCE SOME CLOUDS
ACROSS THE FORECAST AREA OVERNIGHT AND A VERY SLIGHT CHANCE OF SOME
HIGH BASED PRECIPITATION AND OR THUNDERSTORMS OVER THE EASTERN
MOUNTAINS THROUGH EARLY TUESDAY. ONCE THIS SYSTEM EXITS WE WILL BE
UNDER MOSTLY SUNNY SKIES UNTIL THE NEXT SYSTEM BEGINS INCREASING
CLOUDS TUESDAY NIGHT. THIS WILL OCCUR AS THE LONG WAVE TROUGH
APPROACHES THE COAST AND SENDS ANOTHER SHORTWAVE ACROSS THE INLAND
NORTHWEST LATE WEDNESDAY FOLLOWED BY THE TROUGH PASSAGE ON THURSDAY.
HAVE INCREASED PRECIPITATION CHANCES FOR THE WEDNESDAY NIGHT PERIOD
AND THEN DECREASED THEM ON THURSDAY AS INCREASED WESTERLY FLOW WILL
ALLOW THE CASCADE DOWNSLOPE TO CUT OFF PRECIPITATION EXCEPT OVER THE
MOUNTAINS. TEMPERATURES WILL CONTINUE TO RUN ABOVE NORMAL THROUGH
WEDNESDAY THEN COOL ON THURSDAY AS THE WESTERLY FLOW BRINGS IN SOME
COOLER AIR.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY...THE PERIOD STARTS OFF
WITH SOME LEFT OVER CLOUDS AND A SLIGHT CHANCE FOR SHOWERS AS AN
UPPER LEVEL DISTURBANCE GRADUALLY MOVES OUT OF THE AREA. EVENTUALLY
THIS SYSTEM BECOMES A CUTOFF LOW NEAR SOUTHERN CALIFORNIA BY
SATURDAY MORNING. BEHIND THIS WE CAN EXPECT RISING HEIGHTS AS THE
UPPER LEVEL RIDGE BUILDS OVER THE AREA...THIS WILL LEAD TO DRY AND
WARM WEATHER FOR MUCH OF THE UPCOMING WEEKEND WITH TEMPERATURES AT
LEAST 5-10 DEGREES ABOVE AVERAGE. PREVIOUSLY MENTIONED UPPER LEVEL
CUTOFF LOW MEANDERS OR POSSIBLY EVEN RETROGRADES OFF THE CALIFORNIA
COAST INTO MONDAY WITH THE LATEST ECMWF MODEL RUN COMING INTO BETTER
AGREEMENT WITH THE GFS ON THIS SOLUTION. NEXT SYSTEM LIKELY WON`T
APPROACH THE REGION UNTIL AFTER THE EXTENDED PERIOD...PERHAPS THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...00Z TAFS...VFR CONDITIONS FORECAST TO PERSIST ACROSS ALL
TAF SITES THROUGH THE PERIOD. A SHORTWAVE DISTURBANCE LOCATED OFF
THE CENTRAL OREGON COAST WILL CONTINUE TO MOVE NORTHWARD INTO THE
AREA THIS EVENING BRINGING INCREASING HIGH AND MID LEVEL CLOUDS TO
THE TAF SITES. OVERALL THIS SYSTEM WILL REMAIN WEAK AND MOISTURE
STARVED. PROBABILITY FOR SHOWERS OR THUNDERSTORMS WILL BE SLIGHT
CHANCE OR LESS...BUT CANNOT BE COMPLETELY RULED OUT BETWEEN 03Z TO
12Z TUESDAY MAINLY FOR SOUTHERN AND EASTERN TAF SITES AS INDICATED
BY THE LATEST HIGH RESOLUTION NAM AND HRRR MODELS. WINDS WILL REMAIN
LIGHT AND SHOULD FOLLOW THEIR TYPICAL DIURNAL CYCLE FOR THE MOST
PART THROUGH THE PERIOD...HOWEVER IF ANY SHOWERS OR TSMS WERE TO
DEVELOP A BRIEF AND LOCALIZED WIND GUST COULD OCCUR. HIGH CLOUDS
WILL PERSIST ACROSS THE TAF SITES THROUGH TOMORROW AFTERNOON AS THE
REGION REMAINS UNDER A MOIST WEST TO SOUTHWESTERLY UPPER LEVEL FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 52 87 55 86 / 10 10 0 0
ALW 58 89 61 87 / 10 10 0 0
PSC 49 89 54 88 / 0 10 0 0
YKM 50 87 54 85 / 10 10 0 10
HRI 47 89 52 88 / 10 10 0 0
ELN 44 87 57 84 / 10 10 0 10
RDM 42 85 46 83 / 20 0 0 10
LGD 48 89 50 87 / 20 20 10 10
GCD 52 90 52 88 / 20 20 10 10
DLS 53 86 58 85 / 10 10 0 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/78/78/77
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
946 PM CDT MON SEP 15 2014
.UPDATE...
OVERALL...SHORT-TERM FORECAST IS ON TRACK WITH ONLY MINOR
ADJUSTMENTS MADE TO THE OVERNIGHT SKY AND WEATHER GRIDS.
LATEST NAM12...SREF AND RUC13 SOLUTIONS SHOW AN AREA OF ISOLATED
SHOWERS OVERNIGHT ACROSS THE I-35 CORRIDOR...ESPECIALLY OVER
PARTS OF COMAL...HAYS AND TRAVIS COUNTIES. THEREFORE...INCREASED
POP ACROSS THAT AREA TO A 20%. STILL LOOK GOOD FOR RAIN CHANCE
LATE TUESDAY INTO WEDNESDAY AND THURSDAY AS TROPICAL AIRMASS
ARRIVES FROM THE SOUTH AT LOWER LEVELS AND FROM THE NORTHWEST AT
MID TO UPPER LEVEL.
&&
.PREV DISCUSSION... /ISSUED 657 PM CDT MON SEP 15 2014/
AVIATION...
HIGH PRESSURE SHOULD HOLD BACK CLOUD COVER TO VFR THROUGH AT LEAST
07Z DESPITE A GOOD AMOUNT OF AVAILABLE MOISTURE AND SELY LOW LEVEL
WINDS. SOME ISOLATED SEA-BREEZE CONVECTION FORMING OVER THE
COASTAL BEND IS SUGGESTED TO SHIFT FOCUS TO THE I-35 TAF SITES BY
THE FINER RES MODEL DATA TOWARD MIDNIGHT...BUT WITH SLOW STORM
MOTIONS NOTED...WILL LEAVE THIS FEATURE OUT OF THE TAFS FOR NOW.
ABUNDANCE OF HIGH CLOUDS COULD DELAY THE MVFR CIG DEVELOPMENT LATE
TONIGHT AND WILL LOOK AT A POSSIBLE UPDATE FOR THIS SHIFT AS 00Z
MODEL DATA ARRIVES. LATE IN THE PERIOD...A WEAK SURFACE LOW MOVES
ONSHORE INTO DEEP S TX AND NW FLOW DEVELOPS ALOFT...LEAVING MORE
FAVORABLE CONDITIONS FOR CONVECTION IN THE AFTERNOON AND EARLY
EVENING.
PREV DISCUSSION... /ISSUED 305 PM CDT MON SEP 15 2014/
SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
ISOLATED SHOWERS CONTINUE OVER THE HILL COUNTRY AND EDWARDS
PLATEAU...BUT AMOUNTS ARE NEGLIGIBLE AND THE SHOWERS SHOULD MOVE
OFF TO THE NORTHEAST AND OUT OF OUR AREA BY 00Z. THE PRIMARY SHORT
RANGE ISSUE IS THE INCREASE IN MOIST AIR...AT LOW AND MID-LEVELS
FROM THE GULF...AND AT MID- AND UPPER LEVELS FROM PACIFIC HURRICANE
ODILE. WE EXPECT SPRINKLES TONIGHT AS THE MOIST GULF AIR (PW OVER
2 INCHES) UNDERGOES GENTLE LIFT DUE TO TERRAIN. WITHOUT A SIGNIFICANT
LOW LEVEL SOURCE OF LIFT OTHER THAN A WEAK SEA-BREEZE...WE EXPECT
SCATTERED POPS AND MODEST QPF TUESDAY AND TUESDAY NIGHT. TEMPS WILL
REMAIN SLIGHTLY BELOW NORMAL WITH EXTENSIVE CLOUDCOVER AND SCATTERED
STORMS.
LONG TERM (WEDNESDAY THROUGH MONDAY)...
HIGHER POPS AND QPF ARE FORECAST FOR WEDNESDAY AND THURSDAY AS
ODILE BECOMES EXTRATROPICAL AND IS SHEARED/ABSORBED BY A SHORTWAVE
TROUGH MOVING THROUGH THE SOUTHWESTERN STATES. PW SHOULD BE AT OR
ABOVE TWO STANDARD DEVIATIONS ABOVE NORMAL FOR SEPTEMBER...SO WHEN
COMBINED WITH GENERAL LIFT AHEAD OF THE TROUGH AXIS...WILL BRING
MORE SUBSTANTIAL CONVECTION. HOWEVER...WITHOUT A SOURCE OF LOW-
LEVEL LIFT AND FOCUS...WE STILL EXPECT QPF TO ONLY BE IN THE 1/4
OT 1/2 INCH RANGE AT MANY SITES FOR WEDNESDAY THROUGH FRIDAY.
THE SOUTHWESTERN STATES TROUGH IS SLOW TO MOVE OVER THE WEEKEND...
AND MAY BE BOLSTERED BY ANOTHER EASTERN PACIFIC TROPICAL CYCLONE
BY SUNDAY/MONDAY. WE DECIDED TO MAINTAIN POPS EACH DAY...BUT LESS
COVERAGE AND WITH LOW QPF DUE TO A LACK OF LOW-LEVEL FOCUS.
HOWEVER...LESSER CLOUDCOVER AND CONVECTION SHOULD ALLOW
TEMPERATURES TO REBOUND TO NEAR NORMAL. LONGER RANGE MODELS
INDICATE A COLD FRONT PASSAGE JUST BEYOND THIS FORECAST (MIDDLE OF
NEXT WEEK)...WHICH SHOULD LEAD TO CONTINUED LOW TO MODERATE POPS
AND NEAR TO SLIGHTLY BELOW NORMAL TEMPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 72 90 74 91 74 / 20 30 30 30 50
AUSTIN BERGSTROM INTL AIRPORT 69 90 72 90 71 / 20 30 30 30 50
NEW BRAUNFELS MUNI AIRPORT 71 91 73 92 72 / 20 30 30 30 40
BURNET MUNI AIRPORT 71 88 72 90 72 / 10 30 30 40 50
DEL RIO INTL AIRPORT 72 88 75 89 75 / 10 20 30 30 30
GEORGETOWN MUNI AIRPORT 72 88 74 89 73 / 10 30 30 30 50
HONDO MUNI AIRPORT 71 91 73 91 72 / 10 30 30 40 30
SAN MARCOS MUNI AIRPORT 71 90 73 90 73 / 20 30 30 30 40
LA GRANGE - FAYETTE REGIONAL 73 90 74 90 73 / 10 40 30 30 40
SAN ANTONIO INTL AIRPORT 73 91 76 91 75 / 10 30 30 30 40
STINSON MUNI AIRPORT 73 91 75 92 75 / 10 30 30 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
931 PM CDT MON SEP 15 2014
.UPDATE...
Hurricane Odile continues to move to the north-northwest over the
southern Baja Peninsula this evening, fighting against the mid-
level ridge anchored over the southern CONUS. Abundant mid/upper-
level moisture is emanating from this system, moving north and
east into West TX. A band of very light rain showers continues
to drift from west to east across the Concho Valley and Heartland,
essentially running from San Angelo to Brownwood. Additional
isolated showers have developed farther north from near Rotan to
Haskell. The environment remains convectively unstable with
theta-e decreasing with height through approximately 500 mb, but
large scale ascent is somewhat weak. There really isn`t much of a
forcing mechanism and MUCAPE values remain less than 1000 J/kg
(per RAP Mesoanalysis). A cold front to the northwest of the area,
running from near Clovis, NM to Gage, OK, continues to mover very
slowly to the south, but shouldn`t reach the forecast area
tonight.
PoPs were maintained in the 20-30% range overnight but the thunder
was removed from the forecast. Any precipitation that develops
overnight should remain light, with QPF amounts typically under
1/10 of an inch. Wind/sky grids were also modified but overnight
temperatures remain on track.
Johnson
&&
.PREV DISCUSSION... /ISSUED 624 PM CDT MON SEP 15 2014/
AVIATION...
/12Z TAFS/
Mainly VFR conditions expected at the terminals the next 24 hours.
Abundant mid and upper level clouds will remain over the area
tonight into Tuesday. A few light showers will be possible at the
KBBD terminal this evening and have included a TEMPO group for a
couple of hours. Widespread stratus appears unlikely late tonight
into Tuesday morning due to extensive mid and high cloudiness but
cannot rule out some scattered low clouds developing across the
southern terminals towards daybreak. Scattered convection may
develop Tuesday afternoon but will not include thunder at the
terminals due to uncertainty in timing and coverage.
PREV DISCUSSION... /ISSUED 344 PM CDT MON SEP 15 2014/
SHORT TERM...
(Tonight and Tuesday)
As of 3 PM...scattered light rain showers were moving east across
portions of the Heartland between Cross Plains and Cherokee.
These showers will exit the area by late afternoon. Abundant mid
and high level moisture associated with Hurricane Odile will
continue to advect in from the west tonight and Tuesday. A weak
cold front is currently moving south across the Texas Panhandle
and northwest Oklahoma. This front will continue slowly south
overnight and should reach Haskell and Throckmorton counties
around 3 AM. The front is expected to stall along or just north of
I-20 Tuesday morning, before washing out during the afternoon
hours. The best clocalized heavy rainfall. Rainfall amounts,
however remain uncertain, as high cloudiness from Odile remnants
may reduced daytime heating, and thus instability and rainfall
amounts. Rainfall amounts of 1/4 to 1/2 inch are certainly
possible however.
Keeping rain chances in Friday into Saturday with moist tropical
airmass over the region. Any weak disturbance could produce
isolated showers.
Cold front indicated this weekend. GFS model has it moving
through Saturday night/Sunday morning, while the EC is 24 hours
slower. WPC extended discussion indicated a 50-50 blend of the
two models, so best chance of the front would be on Sunday.
Locally heavy rainfall is possible as the front at moves through
the tropical air mass, but uncertainly remains on its timing.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 68 85 70 87 69 / 30 40 30 40 60
San Angelo 69 85 71 87 71 / 30 40 30 50 60
Junction 69 86 72 87 71 / 20 30 30 40 60
&&
.Shance for rainfall overnight will be across the
Big Country, mainly after midnight as the front enters the area.
Maintaining chance POPs for Tuesday as weak shortwave energy from
the remnants of Odile move across the tropical airmass in place
across West Texas. Additional convection will also be possible due
to outflow boundary interactions along and south of the decaying
front. Low temperatures tonight will be near 70. Went slightly
lower than guidance for highs on Tuesday, with temperatures
topping out in the lower to middle 80s.
LONG TERM...
(Tuesday night into Monday)
Tropical moisture will remain over West Central Texas this week,
as Hurricane Odile weakens to depression over Baja California.
While the main remnants of Odile will stay west and north of the
region, weak disturbances will likely ripple eastward across West
Central Texas, especially Wednesday afternoon into Thursday,
Precipitable Water increases to 2 inches at this time, bringing
the potential for JT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
620 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 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 620 PM CDT MON SEP 15 2014
DIURNALLY DRIVEN SCT-BKN CLOUDS WILL DISSIPATE WITH THE LOSS OF THE
SUN THIS EVENING...LEAVING CLEAR SKIES THROUGH THE REST OF THE
NIGHT. THESE SKC/VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH TUE
AS HIGH PRESSURE INFLUENCES FROM THE MID MISSISSIPPI RIVER VALLEY.
THE MAIN AVIATION CONCERN IS FOR VALLEY FOG AT KLSE. MORNING
RAINS/CLOUDS GAVE WAY TO SCATTERED CLOUDS EARLY THIS EVENING. TEMPS
HAVE WARMED A BIT WITH THE LATE AFTERNOON SUN...BUT T/TD SPREAD
STILL RELATIVELY CLOSE...15 F AT 23Z. WINDS WILL BECOME LIGHT WITH
SUNDOWN...AND HOLD VRB03KT THROUGH THE OVERNIGHT. ANOTHER GOOD SETUP
FOR VALLEY FOG. THE DRAWBACK...LIKE IT WAS A COUPLE NIGHTS
AGO...WILL BE THE DEPTH OF THE LIGHT WIND LAYER. LATEST RAP/NAM
BUFKIT SOUNDINGS HAVE 10+ KT WINDS BY 600 FT FOR MOST OF THE
EVENING...WITH RAP INCREASING THE DEPTH TO AROUND 1400 FT
OVERNIGHT...NAM A BIT MORE. NOT FAVORABLE FOR 1/4SM...BUT CAN/T RULE
IT OUT YET EITHER. GOING TO STICK WITH BCFG FOR NOW...AND KEEP A
CLOSE EYE ON OBS/SOUNDINGS.
&&
.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.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 600 PM CDT SUN SEP 14 2014
RAIN CONTINUES TO DEVELOP AND EXPAND EASTWARD ALONG A WEST-EAST
RUNNING FRONTAL BOUNDARY...LAID UP ACROSS SOUTHERN MN INTO WESTERN
WI. THE PCPN IS FALLING OUT OF MID LEVEL CLOUDS CURRENTLY. 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 FOR A FEW HOURS.
MESO MODELS TAKE THIS SYSTEM ACROSS THE REGION DURING THE
AFTERNOON...EXITING BY EARLY EVENING. PCPN SHOULD FOLLOW
SUIT...MOVING EAST/SOUTHEAST OF THE TAF SITES BETWEEN 18-21Z.
SUBSIDENCE POST THE SHORTWAVE ALONG WITH A SFC HIGH INFLUENCING FROM
THE CENTRAL PLAINS SHOULD CLEAR SKIES LATER MON AFTERNOON/EARLY
EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
337 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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1237 PM CDT SUN SEP 14 2014
VFR CONDITIONS LOOK TO DOMINATE THROUGH MUCH OF TONIGHT...DESPITE
THE PASSAGE OF TWO COLD FRONTS. THIS IS DUE TO PLENTY OF DRY AIR.
HOWEVER...AFTER MIDNIGHT...A BAND OF RAIN LOOKS TO SET UP BEHIND
THE PASSAGE OF THE SECOND COLD FRONT. THIS RAIN SHOULD GRADUALLY
LOWER CEILINGS...AND THERE ARE SOME SIGNS THAT A MVFR CEILING
COULD DEVELOP FOR A TIME MONDAY MORNING. INCLUDED A TEMPO GROUP
FOR THIS. NO VISIBILITIES RESTRICTIONS ARE EXPECTED DUE TO THE
AFOREMENTIONED DRY AIR AND LIGHT RAIN RATES. REGARDING
WINDS...GUSTS OF 20-25 KT HAVE DEVELOPED THIS MORNING. THESE
SHOULD CONTINUE UNTIL THE COMBINATION OF ALTOSTRATUS MOVING IN
LATE IN THE DAY AND LOSS OF DAYTIME HEATING STOP THE MIXING. WINDS
WILL DIMINISH FURTHER THIS EVENING WITH A SWITCH TO THE NORTHWEST
IN THE WAKE OF THE SECOND COLD FRONT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...BOYNE
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1106 PM MDT MON SEP 15 2014
.UPDATE...
ISSUED AT 920 PM MDT MON SEP 15 2014
IN THE SHORT TERM...MODELS HINT THAT MOISTURE FROM NEW MEXICO
RETURNS TO SOUTHWEST COLORADO LATE THIS EVENING. THIS IS NOT A
PRONOUNCED MOISTURE SURGE...BUT APPEARS THAT OUTFLOWS FROM SPOTTY
STORMS OVER NW NEW MEXICO (SSE GUSTY WIND AT FARMINGTON) GETS
INTO LA PLATA AND ARCHULETA COUNTIES. THE HRRR DEPICTS SPOTTY
LIGHT PCPN OVERNIGHT...SO ELECTED TO GO THE "ISOLATED" ROUTE
INSTEAD OF "SCATTERED". FOR THE REMAINDER OF THE FORECAST AREA...
LIMITED CONVECTIVE DEBRIS IS DISSIPATING FOR MOSTLY CLEAR
CONDITIONS.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 257 PM MDT MON SEP 15 2014
H5 HAND ANALYSIS AT 12Z HAD THE RIDGE AXIS ALONG THE GREAT BASIN TO
THE FAR WESTERN CANADIAN PROVINCES. THIS RIDGE IS SQUEEZED BETWEEN
AN EXPANSIVE EASTERN TROUGH EXTENDING FROM THE ARCTIC TO THE GREAT
LAKES...AND TROUGH OFF THE WEST COAST OF NOAM. LOWER DOWN A SURFACE
COLD FRONT WAS MAKING IT/S WAY DOWN THE SOUTHERN HIGH PLAINS...BUT
STALLING NEAR THE TX/OX/NM BORDERS LATE THIS AFTERNOON. UPPER JET
MAX HAS SHIFTING EAST AND WITH MINIMAL LARGE SCALE ASCENT OVER
OUR CWA...THE CONVECTION HAS FOCUSED OVER THE HIGHER TERRAIN WITH
PARTICULAR EMPHASIS ALONG THE TAVAPUTS/ROAN PLATEAU AND FLAT TOPS.
NEAR TERM MODELS SUGGEST THIS CONVECTION WILL REMAIN ISOLATED
THROUGH THE EVENING BEFORE DISSIPATING AFTER SUNSET. STRONG EML
SUGGEST WINDS THE BIGGEST THREAT. BOUNDARIES FROM STORMS MAY FORCE
A SHOWER INTO A VALLEY BUT CONFIDENCE FAIRLY LOW. BEST CHANCE FOR
THIS TO OCCUR WITH CURRENT 88D TRENDS IS THE SOUTHERN SAN JUAN
FOOTHILLS AND HAVE PUSHED POPS TO ISOLATED THERE AS WELL.
THE OVERALL PATTERN WILL BE SHIFTING SLIGHTLY OVER THE NEXT 36 TO 48
HOURS AS THE EASTERN TROUGH AXIS LIFTS NORTHEAST AND LOW PRESSURE
DEEPENS OFF THE WEST COAST. THIS WILL PUSH THE RIDGE AXIS ALONG THE
SPINE OF THE ROCKIES. THE RESULT WILL TEMPERATURES WARMING A FEW
DEGREES TOMORROW AND LIMITED CONVECTION AGAIN AS THE SUBSIDENCE
INVERSION SHOULD STRENGTHEN. ONE CHALLENGE WILL BE EARLY MORNING
CONVECTION OR A POSSIBLE PUSH OF LOW CLOUDS TOWARD THE SOUTHERN
VALLEYS. HIGH PRESSURE BUILDING DOWN THE LEE OF THE ROCKIES LOOKS TO
BULGE OVER THE LOWER DIVIDE IN NEW MEXICO WITH THE SOUTHERLY RETURN
FLOW POINTED TOWARD THE 4 CORNERS. AS A RESULT...DEW POINTS
SHOULD BE INCREASING THROUGH THE EARLY MORNING HOURS OVER
CEZ/DRO/PSO. ATTM MODELS SOUNDINGS AND RH FIELDS DO NOT SHOW
STRATUS BUILDING IN...BUT THIS MOISTURE MAY SERVE TO FUEL A BIT
MORE CONVECTION IN THE SOUTHERN SAN JUANS AS MOUNTAIN
CIRCULATIONS LIFT THE MOISTURE UP THE SLOPES TOMORROW AFTERNOON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 257 PM MDT MON SEP 15 2014
THE RIDGE AXIS IS STILL PROJECTED TO BE DIRECTLY OVER THE
FORECAST AREA AROUND NOON ON WEDNESDAY...CREATING A VERY WARM AND
PLEASANT DAY ACROSS THE REGION. A TRANSITION IN THE PATTERN WILL
BEGIN TO OCCUR THURSDAY ACROSS EASTERN UTAH AND THE FOUR CORNERS
REGION AS THE RIDGE SLIDES EAST AND GENERAL SOUTHWEST FLOW
DEVELOPS. PRECIPITABLE WATER VALUES CLIMB TO BETWEEN 0.75 INCHES
AND 1.0 INCHES THURSDAY NIGHT INTO FRIDAY ACROSS THE REGION. THE
REMNANTS OF HURRICANE ODILE ARE PROJECTED TO REACH THE NM/CO
BORDER LATE THURSDAY NIGHT BUT OTHERWISE STAY TO THE SOUTH AND
EAST OF THE FORECAST AREA.
THE DETAILS ON ACTUAL DYNAMIC FORCING MECHANISMS NEAR THE END OF
THE WEEK ARE STILL VERY FUZZY WITH FORECAST MODELS SWITCHING
SOLUTIONS ALMOST EVERY CONSECUTIVE RUN. EXPECT AN UPTICK IN
ACTIVITY AT THE END OF THE WEEK AND INTO THE WEEKEND...BUT VERY
LOW CONFIDENCE ON TIMING AND EXACT THREAT AT THIS TIME. THE LATEST
MODELS SUGGEST A BREAK IN ACTIVITY ON SATURDAY...BUT WITH
MOISTURE STILL IN PLACE THINKING THAT THIS COULD REALLY FUEL
DIURNAL ACTIVITY ON SATURDAY WITH THE ADDED BENEFIT OF BREAKS IN
THE CLOUDS. AT THIS TIME...SUNDAY AND MONDAY LOOK TO BE RELATIVELY
ACTIVE WITH DIURNAL ACTIVITY AS A TROUGH PASSES THROUGH THE GREAT
BASIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1103 PM MDT MON SEP 15 2014
ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS
AFTER 18Z WITH GUSTY WINDS TO 40 MPH...SMALL HAIL AND LOCALLY
HEAVY RAINFALL EXPECTED. A FEW STORMS MAY DRIFT INTO THE VICINITY
OF KTEX...KASE AND KDRO. OTHERWISE...VFR CONDITIONS ARE EXPECTED
TO HOLD THROUGH TUESDAY EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...15
LONG TERM...JAM
AVIATION...JDC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
143 AM EDT TUE SEP 16 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 TODAY/...
130 AM UPDATE...
MODERATE BANDS OF RADAR ECHO ARE TRYING TO MOVE INTO NW MA AND SW
NH...BUT THESE APPEAR TO BE PREDOMINANTLY VIRGA AS SFC OBS
CONTINUE TO SHOW SKIES BKN AT OR ABOVE 10KFT AND NO VSBY
REDUCTIONS. THEREFORE...ITS STILL LIKELY GOING TO TAKE A FEW MORE
HOURS BEFORE THINGS START HITTING THE GROUND. ESPECIALLY IN THE
REGION.
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 /TONIGHT THROUGH 6 PM WEDNESDAY/...
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 NIGHT 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 /06Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT-TERM FORECAST /THROUGH WEDNESDAY/...HIGH CONFIDENCE.
THROUGH TODAY...
PERIODIC SHOWERS WILL GRADUALLY MOVE FROM NW TO SE THROUGH THE
AFTERNOON. CONDITIONS ARE EXPECTED TO REMAIN MOSTLY VFR...BUT A
BRIEF PERIOD OF MVFR MAY ACCOMPANY THESE SHOWERS. CONDITIONS
IMPROVE THROUGH LATE AFTERNOON AND EVENING. LIGHT AND VRB FLOW
THIS MORNING WILL GIVE WAY TO W-NW FLOW FOLLOWING A WEAK COLD
FRONTAL PASSAGE...SOME SEA BREEZES POSSIBLE LATE MORNING-
AFTERNOON.
TONIGHT AND WED...
MAINLY VFR. SOME FOG POSSIBLE AT TYPICALLY PRONE AIRPORTS LATE
TONIGHT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF OVERALL. LOWER CONFIDENCE
IN EXACT TIMING OF A POTENTIAL SEA BREEZE.
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...DOODY/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...RLG
AVIATION...DOODY/SIPPRELL
MARINE...RLG/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
440 AM EDT TUE SEP 16 2014
.SHORT TERM...
A WEAK FRONTAL BOUNDARY CURRENTLY APPROACHING THE FL PANHANDLE THIS
MORNING WILL BE THE PRIMARY WEATHER FACTOR IN THE SHORT TERM. THIS
FRONT WILL SLOWLY MAKE ITS WAY THROUGH THE FLORIDA PENINSULA TODAY
AND TOMORROW. FOR TODAY...A TRICKY FORECAST AS WE ARE ALREADY
SEEING WIDESPREAD SHOWERS AND EVEN A FEW THUNDERSTORMS ACROSS LEVY
COUNTY. GIVEN THE OVERALL COVERAGE ALREADY WENT WITH CATEGORICAL/LIKELY
POPS OVER THE NORTHERNMOST PORTION OF THE CWA. THE REST OF THE DAY IS
WHERE IT GETS TRICKY AS THE MAIN FORECAST CHALLENGE IS DETERMINING HOW
FAR SOUTH THE RAIN WILL GET. AFTER INITIALLY FORECASTING LIKELY
POPS FROM TAMPA BAY NORTH FOR THE AFTERNOON DECIDED TO HOLD OFF
AND KEEP HIGH END SCATTERED COVERAGE GIVEN LESS THAN DESIRED
CONFIDENCE. THAT BEING SAID...RECENT HRRR RUNS HAVE BECOME MORE
BULLISH ON THE SOUTHERNMOST EXTENT OF SHRA/TSTM COVERAGE SO MORE
CHANGES MAY BE MADE TO THE FORECAST BY DAYBREAK. SW FLORIDA RAIN
CHANCES NOT QUITE AS HIGH BEING FURTHER AWAY FROM THE FRONTAL
BOUNDARY HOWEVER SCT COVERAGE IS LIKELY DURING THE AFTERNOON AND
EARLY EVENING HOURS.
AS FAR AS TEMPS ARE CONCERNED THEY WILL BE HIGHLY DEPENDENT ON CLOUD
COVER AND RAIN. 00Z MET SEEMED TO HAVE A GOOD HANDLE ON THE SYNOPTIC
SETUP OVER THE AREA AND SHOWED RAIN/CLOUD TEMPS FROM TAMPA BAY NORTH
SO TEMP FORECAST HEAVILY WEIGHTED TOWARD THE MET SOLUTION.
SIMILAR FORECAST CONCERNS ON WEDNESDAY AS THE AFOREMENTIONED
BOUNDARY WILL CONTINUE TO BE PUSHING THROUGH THE AREA. GUIDANCE
SUITE ALL IN GOOD AGREEMENT OF ANOTHER WET DAY FOR MUCH OF THE AREA.
MAINTAINED HIGH-END SCATTERED TO NUMEROUS COVERAGE FOR MUCH OF THE
AREA. ONCE AGAIN LEANED TOWARDS THE 00Z MET FOR TEMPS ON WEDNESDAY
AS AREAS CLOUD COVER AND RAIN SHOULD KEEP MOST AREAS IN THE MIDDLE
TO UPPER 80S AT BEST FOR HIGH TEMPERATURES.
.LONG TERM...
THE LONG TERM FORECAST PERIOD WILL BEGIN ON THURSDAY WITH AN UPPER
LEVEL LONGWAVE PATTERN CONSISTING OF RIDGING OVER THE INTER-MOUNTAIN
WEST AND DOWNSTREAM TROUGHING OVER THE EASTERN CONUS. AS THE WEEK
PROGRESSES AND WE HEAD INTO THE UPCOMING WEEKEND...THE RIDGE AXIS
WILL MIGRATE EASTWARD AND SLOWLY DEAMPLIFY THE EASTERN TROUGH.
HOWEVER...GLOBAL MODELS ARE STUBBORN AND KEEP AT LEAST SOME PIECE OF
UPPER LEVEL ENERGY OVER THE FLORIDA PENINSULA. THE GFS IS MORE
ORGANIZED AND STRUCTURED WITH ITS ENERGY BEGIN A DEFINED PART OF
LEFTOVER TROUGHING ALONG THE EASTERN SEABOARD...WHILE THE ECMWF
SHOWS MORE FRACTURED...OR ENERGY LEFT BEHIND FROM THE THEN DEPARTED
TROUGH.
EITHER WAY...THE FORECAST FOR THE LATER HALF OF THE WEEK IS LOOKING
LIKE IT WILL BE A MESSY PATTERN. THIS IS NOT TO SAY THAT THE WEATHER
ITSELF WILL BE OVERLY INCLEMENT...BUT RATHER THAT FORECAST DETAILS
WILL BE MORE DIFFICULT TO COME BY...AND THEREFORE FORECAST
CONFIDENCE IS A BIT LOWER THAN AVERAGE (ESPECIALLY BEYOND FRIDAY).
FOR THURSDAY...THE FL PENINSULA IS FIRMLY UNDERNEATH THE UPPER TROUGH
WITH DEEP LAYER CYCLONIC FLOW. ANOTHER WEAK SURFACE FRONT WILL BE
MIGRATING ACROSS THE REGION...BUT AGAIN DOES NOT LOOK LIKE MUCH IN
THE WAY OF COOLER AIR WILL BE ARRIVING INTO THE REGION. A LARGE AREA
OF CONTINENTAL HIGH PRESSURE WILL BECOME ESTABLISHED OVER THE
NORTHEAST PORTION OF THE COUNTRY AND RIDGE ALL THE WAY DOWN THE
EASTERN SEABOARD INTO NORTHERN FLORIDA IN THE WAKE OF THE FRONTAL
PASSAGE.
WITHOUT A DEFINED FRONTAL PASSAGE TO CLEAR OUT THE AVAILABLE
MOISTURE...AND WILL LEFTOVER ENERGY ALOFT THROUGH MUCH OF THE
PERIOD...WILL HAVE TO KEEP SHOWER CHANCES IN THE FORECAST EACH DAY.
TOUGH TO SAY WHICH DAYS WILL SEE THE MOST SHOWER ACTIVITY AT THIS
POINT DUE TO THE ILL-DEFINED NATURE OF THE PATTERN...AND DIFFERENCES
BETWEEN THE ENSEMBLE MEMBERS THEMSELVES AS TO THE EXACT EVOLUTION OF
THE UPPER TROUGH. WITHOUT ANY ABNORMAL HEIGHTS...OR CLOUDY/WASHOUT
DAYS EXPECTED...WILL KEEP TEMPERATURES NEAR CLIMO THROUGH THE
UPCOMING WEEKEND AND FOR NOW KEEP SHOWER CHANCES CONSERVATIVE.
HOPEFULLY A MORE DEFINED PATTERN BETWEEN THE MEMBERS WILL EMERGE IN
THE NEXT DAY OR TWO.
&&
.AVIATION...
VFR CONDITIONS EXPECTED OUTSIDE OF STORMS WITH WESTERLY WINDS IN
PLACE ACROSS THE AREA. VCSH/VCTS POSSIBLE FOR ALL TERMINALS TODAY
STARTING AS EARLY AS 15Z AROUND THE BAY AREA TERMINALS AND 18-20Z
FOR SW FLORIDA TERMINALS. LOCALIZED REDUCTIONS TO MVFR/IFR WILL BE
POSSIBLE.
&&
.MARINE...
WINDS SHOULD REMAIN BELOW 15 KNOTS IN THE SHORT TERM WITH SEAS 2
FEET OR LESS. THE MAIN CONCERN WILL BE THE BAND OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH A FRONTAL BOUNDARY PUSHING THROUGH THE
REGION. THIS WILL IMPACT THE COASTAL WATERS TODAY AND TOMORROW. SOME
LOCALLY HIGHER WINDS AND SEAS WILL BE POSSIBLE NEAR THE STRONGEST
STORMS.
&&
.FIRE WEATHER...
NO CONCERNS OVER THE NEXT FEW DAYS AS MUCH OF THE AREA SHOULD SEE
RAINFALL ALONG WITH RH VALUES REMAINING WELL ABOVE CRITICAL THRESHOLDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 74 85 75 / 50 50 60 30
FMY 92 75 88 73 / 40 40 60 50
GIF 89 73 86 72 / 50 40 60 30
SRQ 89 76 84 76 / 50 40 60 40
BKV 88 71 86 68 / 60 50 50 20
SPG 88 76 84 77 / 50 50 60 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...11/MCKAUGHAN
LONG TERM...14/MROCZKA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
314 AM CDT TUE SEP 16 2014
.DISCUSSION...
221 PM CDT
TONIGHT...
FRONTAL BOUNDARY THIS AFTERNOON CONTINUES TO SLIDE SOUTHEAST ACROSS
THE FORECAST AREA. VISIBLE IMAGERY ALONG AND JUST AHEAD OF THE
BOUNDARY INDICATED SOME VERTICAL GROWTH TO THE CLOUDS...SUGGESTIVE
OF SOME INSTABILITY. THERE HAS BEEN SOME SPOTTY CONVECTION ACROSS
NORTHEAST MO STRETCHING EAST THROUGH IL/CENTRAL IN BUT SOUTH OF THE
CWFA. DESPITE CONSIDERABLE SOLAR SHIELDING HAS BEEN ABLE TO KEEP
TEMPS IN THE 50S...WITH A FEW LOCATIONS BEING ABLE TO NUDGE TO ARND
60. WINDS WILL SHIFT NORTHWEST/NORTH BEHIND THE BOUNDARY WITH MUCH
DRIER/COOLER AIR STEADILY FILTERING INTO THE REGION OVERNIGHT.
PRECIP WILL COME TO AN END LATER THIS AFTN/EARLY EVE...WITH JUST A
FEW LINGERING SHOWERS ALONG AND EAST OF GIBSON CITY TO FOWLER. TEMPS
OVERNIGHT WILL COOL INTO THE LOW/MID 40S...WITH A FEW OF THE
TRADITIONALLY COOL SPOTS POSSIBLY DIPPING INTO THE UPR 30S BEFORE
DAYBREAK TUE. MEANWHILE CLOSER TO DOWNTOWN CHICAGO...THE URBAN HEAT
ISLAND SHUD AID IN KEEPING TEMPS IN THE UPR 40S TO ARND 50. THE ONLY
WILDCARD FOR OVERNIGHT LOWS WILL BE SKY COVER/WINDS...WHICH WITH
HIGH PRESSURE BUILDING IN SHUD ERODE/DIMINISH.
THERE IS ALSO SOME CONCERN THAT WITH THE LACK MIXING THIS AFTN AND
EXPECTED TEMPS BEING COOLER THAN AFTN DEW PTS...COUPLED WITH LIGHT
WINDS...COULD POINT TOWARDS PATCHY FOG DEVELOPING AWAY FROM THE
METRO AREA.
TUESDAY THROUGH THURSDAY...
RATHER BENIGN PATTERN FOR A GOOD PORTION OF THE WEEK. BROAD
ANTI-CYCLONIC FLOW WILL BUILD INTO THE REGION TUESDAY...WITH THE
MID-LVL TROUGH PIVOTING EAST. THE LONGWAVE PATTERN WILL LIKELY KEEP
THE REGION IN A CONTINUED NORTHWEST FLOW AS MID-LVL RIDGING RETURNS
TO THE WESTERN CONUS. GUIDANCE SUGGESTS THE SFC RIDGE THAT ARRIVES
TUE WILL SHIFT EAST...HOWEVER ANOTHER DOME OF HIGH PRESSURE FROM
CANADA IS THEN POISED TO SLIDE SOUTH AND CONTINUE THE DRY/COOL
WEATHER WED/THUR. TEMPS WILL GENERALLY REMAIN IN THE MID/UPR
60S...BUT POSSIBLY REACH 70 DEG IN SEVERAL AREAS FOR THUR. ABUNDANT
SUNSHINE IS EXPECTED EACH OF THE NEXT SEVERAL DAYS AS WELL.
OVERNIGHT LOWS WILL ALSO DIP INTO THE 40S TUE NGT/WED NGT...THEN
WITH THE SFC RIDGE BEGINNING TO PUSH EAST THUR NGT TEMPS COULD HOLD
ARND 50.
CONFIDENCE...HIGH.
FRIDAY THROUGH SUNDAY...
WITH THE SFC RIDGE POISED TO PUSH EAST OF THE REGION FRI...FLOW WILL
BE TURNING SOUTHERLY AND THE MID-LVL WAVE STARTING TO FLATTEN.
ENSEMBLES CONTINUE TO SHOW CONSIDERABLE SPREAD ON TIMING OF
PRECIP/MOISTURE RETURNING...WITH MOST MEMBERS POINTING TOWARDS FRI
NGT. THE ATMOSPHERE WILL MODERATE BY FRI/SAT WITH TEMPS IN THE
MID/UPR 70S...OR MORE SEASONAL. SAT APPEARS TO BE THE MOST FAVORABLE
PERIOD TO SEE SPOTTY SHOWERS/THUNDERSTORMS AS A MID-LVL TROUGH
DEVELOPS OVER THE CENTRAL PLAINS AND NEARS THE REGION SAT AFTN/EVE.
THEN FOR THE SECOND HALF OF THE WEEKEND SFC RIDGING IS PROGGED TO
RETURN TO THE REGION.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* FOG POTENTIAL EARLY TUESDAY.
* LAKE BREEZE POTENTIAL TUESDAY AFTERNOON.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE WILL BUILD TO THE SOUTH OF THE TERMINALS TONIGHT
KEEPING WINDS VERY LIGHT AND ALLOWING CONDITIONS TO REMAIN
GENERALLY VFR OUTSIDE OF SOME FOG THIS MORNING. PATCHY FOG HAS
ALREADY DEVELOPED IN SOME AREAS AND WILL MOST LIKELY IMPACT
RFD/DPA WITH CONFIDENCE TOO LOW AT ORD/MDW/GYY AT THIS TIME TO
INCLUDE ANY MENTION IN THE TAF. WINDS WILL REMAIN LIGHT GENERALLY
4-7 KT THROUGH THE DAY TUESDAY OUT OF THE NORTHWEST THOUGH THERE
MAY BE SOME VARIABILITY IN DIRECTION DUE TO THE LIGHT MAGNITUDE.
WILL ALSO HAVE TO MONITOR A LAKE BREEZE MONDAY AFTERNOON. FOR NOW
EXPECT A LAKE BREEZE TO DEVELOP BUT STAY NEAR THE SHORE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN FOG IMPACTING TERMINALS.
* LOW CONFIDENCE THAT A LAKE BREEZE WILL PUSH FAR INLAND.
* HIGH CONFIDENCE IN VFR CONDITIONS AND WINDS LESS THAN 10 KT
THROUGH PERIOD.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. LIGHT WEST WINDS. LAKE BREEZE POSSIBLE.
THURSDAY...VFR. EAST WINDS.
FRIDAY...VFR. BREEZY SOUTH WINDS.
SATURDAY...CHANCE TSRA. MVFR POSSIBLE. BREEZY SOUTHWEST WINDS.
SUNDAY...SLIGHT CHANCE TSRA. VFR. WEST WINDS.
MDB
&&
.MARINE...
314 AM CDT
HIGH PRESSURE WILL BUILD ACROSS SOUTHERN LAKE MICHIGAN TODAY
ALLOWING WINDS TO DIMINISH...HOWEVER NORTHERN LAKE MICHIGAN WILL
SEE SOUTHWEST FLOW FRESHEN UP AHEAD OF THE NEXT COLD FRONT. THE
FRONT WILL SAG SOUTH ACROSS THE LAKE WEDNESDAY WITH HIGH PRESSURE
QUICKLY BUILDING IN BEHIND CAUSING A SHARP INCREASE IN WINDS
BEHIND THE FRONT INTO THE 20 TO 25 KT RANGE OUT OF THE NORTHEAST
WEDNESDAY EVENING. WINDS WILL VEER BACK AROUND TO THE SOUTHEAST
THURSDAY AND THURSDAY NIGHT DIMINISHING...THEN SOUTH TO SOUTHWEST
FRIDAY INCREASING BACK INTO THE 20 TO 25 KT RANGE...POSSIBLY 30 KT
AS BROAD LOW DEVELOPS OVER THE PLAINS AND CANADIAN PRAIRIES.
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
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WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
230 AM CDT Tue Sep 16 2014
.SHORT TERM...(Today)
ISSUED AT 230 AM CDT TUE SEP 16 2014
Quiet weather expected overall today across central and southeast
Illinois. Canadian high pressure and its associated dry air mass will
continue to build into the area today, helping to scour out the low
clouds that currently reside across much of the forecast area. The
low clouds have been clearing slowly from the north as the high
builds in, and the latest trends suggest the clearing should reach
the I-70 corridor by 10 a.m. this morning. Once the skies clear,
mostly sunny skies should be the rule, as forecast soundings and CU
rule suggest diurnal cloud development should be minimal. The
possible exception to the clearing sticking, at least until sunrise,
is the potential for fog/stratus development. This development has
been patchy thus far upstream, and do not expect it to become too
widespread. Temperatures today, as they have been more often than
not lately, will be well below normal with highs mainly in the
mid-upper 60s.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 230 AM CDT TUE SEP 16 2014
High pressure building southeast into the Great Lakes to dominate
our weather through Thursday. Latest model guidance continues to
indicate some sort of MCS type activity across Missouri and Kansas
Wednesday into Thursday, sliding along the edge of the upper ridge
that will slowly inch eastward into the Plains. However, the
persistent east/northeast flow over our area should keep this
precipitation at bay.
Significant shortwave will dig as it crosses the Rockies on Friday,
settling into the Mississippi Valley by Sunday morning. Have largely
kept the forecast dry through about midday Saturday, then quickly
increased the PoP`s from west to east during the afternoon and
evening hours, as the front arrives. One significant item of concern
is with the potential for heavy rain. The remnants of tropical
cyclone Odile over Baja California will be spreading into the Desert
Southwest over the next day or so. The latest GFS model continues to
show that a piece of energy and associated moisture from this system
will be drawn northeast into the northern wave, reaching central
Illinois after midnight Saturday night with the potential for a few
inches of rain. The ECMWF and Canadian models are not quite as
generous on this point, but do draw in some of the moisture into the
wave by Saturday morning and produce weekend rainfalls of up to 1.5
inches. Have increased PoP`s Saturday night to around 60% across
most of the forecast area, as confidence increases in the general
rainfall trend over the area. Continued the PoP`s on Sunday east of
I-55, although this should be winding down during the afternoon as
the front exits the area.
A large broad upper trough will persist over the Midwest early next
week in the wake of this system. Latest ECMWF model has
significantly backed down on the amount of cool air with this
system, with 850 mb temperatures on Monday now around +5C rather
than the -2C from the previous run. The GFS lags behind the ECMWF
with bringing the cooler conditions into the area. As a result, have
kept highs in the 70s on Sunday and Monday, with the coolest
conditions just beyond the current forecast period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1137 PM CDT MON SEP 15 2014
Precip has departed well to the southeast of all terminal sites,
with clearing of the clouds expected to reach PIA by 05z and
progressing to CMI/DEC around 0730z. Still expect some fog
formation after the clearing develops, with a few areas developing
VLIFR ceilings and fog. A bit of a tough call on timing and
coverage of any dense fog, but for now BMI and CMI were the only
two locations with LIFR/VLIFR conditions between 11z-13z. The
latest HRRR keeps low vis east of CMI, with lingering low clouds
after midnight at all sites by PIA. It is possible that a stratus
layer forms instead of ground fog, but will lean toward fog
formation with this set of TAFs.
Skies should clear out quickly Tues morning with very dry air
above the shallow layer of moisture. Clear skies will continue
through the remainder of the TAF period to 06z/16.
Winds have become N behind the departing cold front, with a brief
increase in wind speeds to 10-12kt. Light winds should prevail the
remainder of the night and into Tuesday, as high pressure keeps
the pressure gradient weak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAK
LONG TERM...GEELHART
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1229 AM CDT TUE SEP 16 2014
.DISCUSSION...
221 PM CDT
TONIGHT...
FRONTAL BOUNDARY THIS AFTERNOON CONTINUES TO SLIDE SOUTHEAST ACROSS
THE FORECAST AREA. VISIBLE IMAGERY ALONG AND JUST AHEAD OF THE
BOUNDARY INDICATED SOME VERTICAL GROWTH TO THE CLOUDS...SUGGESTIVE
OF SOME INSTABILITY. THERE HAS BEEN SOME SPOTTY CONVECTION ACROSS
NORTHEAST MO STRETCHING EAST THROUGH IL/CENTRAL IN BUT SOUTH OF THE
CWFA. DESPITE CONSIDERABLE SOLAR SHIELDING HAS BEEN ABLE TO KEEP
TEMPS IN THE 50S...WITH A FEW LOCATIONS BEING ABLE TO NUDGE TO ARND
60. WINDS WILL SHIFT NORTHWEST/NORTH BEHIND THE BOUNDARY WITH MUCH
DRIER/COOLER AIR STEADILY FILTERING INTO THE REGION OVERNIGHT.
PRECIP WILL COME TO AN END LATER THIS AFTN/EARLY EVE...WITH JUST A
FEW LINGERING SHOWERS ALONG AND EAST OF GIBSON CITY TO FOWLER. TEMPS
OVERNIGHT WILL COOL INTO THE LOW/MID 40S...WITH A FEW OF THE
TRADITIONALLY COOL SPOTS POSSIBLY DIPPING INTO THE UPR 30S BEFORE
DAYBREAK TUE. MEANWHILE CLOSER TO DOWNTOWN CHICAGO...THE URBAN HEAT
ISLAND SHUD AID IN KEEPING TEMPS IN THE UPR 40S TO ARND 50. THE ONLY
WILDCARD FOR OVERNIGHT LOWS WILL BE SKY COVER/WINDS...WHICH WITH
HIGH PRESSURE BUILDING IN SHUD ERODE/DIMINISH.
THERE IS ALSO SOME CONCERN THAT WITH THE LACK MIXING THIS AFTN AND
EXPECTED TEMPS BEING COOLER THAN AFTN DEW PTS...COUPLED WITH LIGHT
WINDS...COULD POINT TOWARDS PATCHY FOG DEVELOPING AWAY FROM THE
METRO AREA.
TUESDAY THROUGH THURSDAY...
RATHER BENIGN PATTERN FOR A GOOD PORTION OF THE WEEK. BROAD
ANTI-CYCLONIC FLOW WILL BUILD INTO THE REGION TUESDAY...WITH THE
MID-LVL TROUGH PIVOTING EAST. THE LONGWAVE PATTERN WILL LIKELY KEEP
THE REGION IN A CONTINUED NORTHWEST FLOW AS MID-LVL RIDGING RETURNS
TO THE WESTERN CONUS. GUIDANCE SUGGESTS THE SFC RIDGE THAT ARRIVES
TUE WILL SHIFT EAST...HOWEVER ANOTHER DOME OF HIGH PRESSURE FROM
CANADA IS THEN POISED TO SLIDE SOUTH AND CONTINUE THE DRY/COOL
WEATHER WED/THUR. TEMPS WILL GENERALLY REMAIN IN THE MID/UPR
60S...BUT POSSIBLY REACH 70 DEG IN SEVERAL AREAS FOR THUR. ABUNDANT
SUNSHINE IS EXPECTED EACH OF THE NEXT SEVERAL DAYS AS WELL.
OVERNIGHT LOWS WILL ALSO DIP INTO THE 40S TUE NGT/WED NGT...THEN
WITH THE SFC RIDGE BEGINNING TO PUSH EAST THUR NGT TEMPS COULD HOLD
ARND 50.
CONFIDENCE...HIGH.
FRIDAY THROUGH SUNDAY...
WITH THE SFC RIDGE POISED TO PUSH EAST OF THE REGION FRI...FLOW WILL
BE TURNING SOUTHERLY AND THE MID-LVL WAVE STARTING TO FLATTEN.
ENSEMBLES CONTINUE TO SHOW CONSIDERABLE SPREAD ON TIMING OF
PRECIP/MOISTURE RETURNING...WITH MOST MEMBERS POINTING TOWARDS FRI
NGT. THE ATMOSPHERE WILL MODERATE BY FRI/SAT WITH TEMPS IN THE
MID/UPR 70S...OR MORE SEASONAL. SAT APPEARS TO BE THE MOST FAVORABLE
PERIOD TO SEE SPOTTY SHOWERS/THUNDERSTORMS AS A MID-LVL TROUGH
DEVELOPS OVER THE CENTRAL PLAINS AND NEARS THE REGION SAT AFTN/EVE.
THEN FOR THE SECOND HALF OF THE WEEKEND SFC RIDGING IS PROGGED TO
RETURN TO THE REGION.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* FOG POTENTIAL EARLY TUESDAY.
* LAKE BREEZE POTENTIAL TUESDAY AFTERNOON.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE WILL BUILD TO THE SOUTH OF THE TERMINALS TONIGHT
KEEPING WINDS VERY LIGHT AND ALLOWING CONDITIONS TO REMAIN
GENERALLY VFR OUTSIDE OF SOME FOG THIS MORNING. PATCHY FOG HAS
ALREADY DEVELOPED IN SOME AREAS AND WILL MOST LIKELY IMPACT
RFD/DPA WITH CONFIDENCE TOO LOW AT ORD/MDW/GYY AT THIS TIME TO
INCLUDE ANY MENTION IN THE TAF. WINDS WILL REMAIN LIGHT GENERALLY
4-7 KT THROUGH THE DAY TUESDAY OUT OF THE NORTHWEST THOUGH THERE
MAY BE SOME VARIABILITY IN DIRECTION DUE TO THE LIGHT MAGNITUDE.
WILL ALSO HAVE TO MONITOR A LAKE BREEZE MONDAY AFTERNOON. FOR NOW
EXPECT A LAKE BREEZE TO DEVELOP BUT STAY NEAR THE SHORE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN FOG IMPACTING TERMINALS.
* LOW CONFIDENCE THAT A LAKE BREEZE WILL PUSH FAR INLAND.
* HIGH CONFIDENCE IN VFR CONDITIONS AND WINDS LESS THAN 10 KT
THROUGH PERIOD.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. LIGHT WEST WINDS. LAKE BREEZE POSSIBLE.
THURSDAY...VFR. EAST WINDS.
FRIDAY...VFR. BREEZY SOUTH WINDS.
SATURDAY...CHANCE TSRA. MVFR POSSIBLE. BREEZY SOUTHWEST WINDS.
SUNDAY...SLIGHT CHANCE TSRA. VFR. WEST WINDS.
MDB
&&
.MARINE...
246 PM CDT
WEAK LOW PRESSURE WILL PUSH EAST THROUGH THE OHIO VALLEY AND
DISSIPATE THIS EVENING AS HIGH PRESSURE MOVES INTO THE MID
MISSOURI VALLEY TONIGHT. AHEAD OF THE HIGH A WEAK COLD FRONT WILL
SPREAD DOWN THE REMAINDER OF THE LAKE THIS EVENING AND BRIEFLY
INCREASE NORTH WINDS TO NEAR 20 KT THE HIGH WILL WEAKEN AND MOVE
OVER LAKE MICHIGAN ON TUESDAY. LOW PRESSURE OVER HUDSON BAY WILL
SPREAD INTO QUEBEC ON WEDNESDAY AS HIGH PRESSURE PUSHES SOUTH OUT
OF NORTHERN MANITOBA. AHEAD OF THE HIGH THE SOUTHWEST GRADIENT
INCREASES WITH WINDS 15 TO 25 KT FOR THE NORTH HALF OF THE LAKE. THE
HIGH REACHES LAKE SUPERIOR THURSDAY EVENING AND WILL PUSH A COLD
FRONT DOWN THE LAKE THURSDAY NIGHT. THIS HIGH WILL THEN MOVE TO
THE EASTERN LAKES BY LATE THURSDAY INTO FRIDAY AS SEVERAL LOWS
ORGANIZE IN THE CENTRAL PLAINS AND CANADIAN PRAIRIES.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1138 PM CDT Mon Sep 15 2014
.UPDATE...
ISSUED AT 900 PM CDT MON SEP 15 2014
Showers and drizzle are departing quickly to the southeast, with
the back edge of the clouds approaching faster than previously
expected as well. The latest HRRR is indicating a band of low
clouds are expected to redevelop behind the clearing, moving into
our counties from the northeast toward Lake Michigan. Low level
wind patterns and obs from that area show some support for that
solution. Have updated the sky grids to acknowledge both the
initial clearing and subsequent clouds from the NE for a few hours
after. Any areas that clear out will have a good chance of seeing
fog develop. The light winds later tonight could set the stage for
locally dense fog, especially NW of I-55 where clearing will
develop sooner. Dewpoints will remain relatively high for enough
hours after clearing that lows will drop very close to the
dewpoint in those areas. Added fog to the weather grids
accordingly. Updated info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 321 PM CDT MON SEP 15 2014
Storm system still impacting Central Illinois ahead of an
approaching boundary. Some low clouds and developing fog in the
wake of the showers hint to the main issues going into the overnight
hours tonight. Showers and thunderstorms should begin to wrap up
this evening but wet, misty, and low clouds should continue for a
little while at least. Satellite imagery showing the low clouds
hanging around a bit after the wind shift/boundary moves through
with the NW/N winds. Cooler tonight...but coolest in the NW where
most likely to see some clearing. Temps may bottom out locally if
the cigs clear in the overnight. Either way, enhanced llvl moisture
will bring with it the chance for fog development. For now,
question is between dense fog and very low stratus. Stratus already
developing and see no reason to break that trend, so only putting in
patchy fog mention in the overnight hours.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 321 PM CDT MON SEP 15 2014
The medium and long range models are in generally good agreement
that a progressive upper level flow pattern will dominate through
the next seven days.
Surface high pressure from the northern Plains will work its way
toward the Midwest Tuesday, resulting in a clearing sky and a
continuation of cooler than normal temperatures. A weak shortwave
trough in the upper level northwest flow will approach the
mid-Mississippi River valley Wednesday. However, an abundance of dry
air in the lower levels should keep central and eastern IL
rain-free. Would not be surprised to see a sprinkle or two in areas
southwest of a Rushville-Springfield line. Will hold off on the
mention of that for now as the favorable moisture and lift appears
to stay along and west of the MS River.
Anticyclonic low level flow will continue to dominate through
Thursday and Friday keeping rain out of the forecast. A return,
southerly flow Friday will finally allow temperatures to climb
toward seasonal levels in the 75-80 range across most of central and
southeast IL.
Will keep the potential for showers and thunderstorms in the
forecast west of I-57 Saturday, and across all of central and
eastern IL Saturday night. The European and GFS models are actually
in quite good agreement that an upper level trough will advance from
the Rockies Friday to the Midwest later Saturday. The southerly low
level flow will advect plenty of moisture ahead of the surface cold
front, resulting in showers and thunderstorms. However, there is the
potential for heavy rain from this system, particularly according to
the GFS solution. The GFS depicts the remnants of Hurricane Odile,
currently in the southern California Baja region, ejecting toward
the central U.S. with deep tropical moisture. This would easily
result in 1-3" of rain across much of the forecast area Saturday
into early Sunday. However, the European and Canadian models are not
buying into this solution at the moment. As a result, will watch
this potential for the next several forecast runs before introducing
a mention of heavy rain.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1137 PM CDT MON SEP 15 2014
Precip has departed well to the southeast of all terminal sites,
with clearing of the clouds expected to reach PIA by 05z and
progressing to CMI/DEC around 0730z. Still expect some fog
formation after the clearing develops, with a few areas developing
VLIFR ceilings and fog. A bit of a tough call on timing and
coverage of any dense fog, but for now BMI and CMI were the only
two locations with LIFR/VLIFR conditions between 11z-13z. The
latest HRRR keeps low vis east of CMI, with lingering low clouds
after midnight at all sites by PIA. It is possible that a stratus
layer forms instead of ground fog, but will lean toward fog
formation with this set of TAFs.
Skies should clear out quickly Tues morning with very dry air
above the shallow layer of moisture. Clear skies will continue
through the remainder of the TAF period to 06z/16.
Winds have become N behind the departing cold front, with a brief
increase in wind speeds to 10-12kt. Light winds should prevail the
remainder of the night and into Tuesday, as high pressure keeps
the pressure gradient weak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...HJS
LONG TERM...MILLER
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
207 AM EDT TUE SEP 16 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 LOWER 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 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 159 AM EDT TUE SEP 16 2014
CHALLENGING AVIATION FORECAST FOR THE NEXT 6 TO 9 HOUR PERIOD.
TERMINALS ARE NOW LOCATED WEST OF DEPARTING SURFACE TROUGH WHICH
HAS ALLOWED WINDS TO COME AROUND TO THE NORTH NORTHWEST 5 KNOTS OR
LESS. STRATUS PERSISTS ACROSS MUCH OF THE AREA BEHIND THIS TROUGH
WITH SHALLOW LOW LEVEL MOISTURE REMAINING IN PLACE. SOME PATCHY
AREAS OF CLEARING HAVE ALLOWED FOR LOCALIZED DENSE FOG AND LIFR
CONDITIONS AS EXPERIENCED AT KFWA OVER THE PAST HOUR. IFR AND
POSSIBLY LIFR CONDITIONS CAN BE EXPECTED AT KFWA THROUGH 08Z..AND
HAVE TRENDED KFWA TO IFR AFTER 08Z. SLIGHTLY DRIER LOW LEVEL AIR
IS EXPECTED TO WORK INTO KSBN OVERNIGHT...BUT PATCHY STRATUS OFF
LAKE MICHIGAN SHOULD TEND TO KEEP AT LEAST MVFR CIGS IN PLACE.
EXPECTING IMPROVEMENTS TO VFR BY LATE MORNING...WITH SOME SHORT
TERM MODEL GUIDANCE INDICATING BEST POTENTIAL OF DIURNAL LOW CLOUD
REDEVELOPMENT JUST DOWNWIND OF LAKE MICHIGAN. HOWEVER...WOULD
EXPECT THIS TO BE OF THE VFR VARIETY BY THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...AGD
LONG TERM...STEINWEDEL
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
330 AM CDT TUE SEP 16 2014
...UPDATE TO LONG TERM...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 114 AM CDT TUE SEP 16 2014
THIS MORNING WILL BE PLAGUED BY WIDESPREAD FOG AND LOW CEILINGS.
THERE IS ABUNDANT MOISTURE AT THE LOWER LAYERS AND THE LIGHT WINDS
WILL ALLOW THE TEMP/DEWPOINT DEPRESSION TO WITHER TO 1 TO 2 DEGREES
APART. THIS FOG SHOULD START IN OUR NORTHWEST ZONES FIRST NEAR
SYRACUSE AND SCOTT CITY, AND SPREAD SOUTHEASTWARD BETWEEN 09Z AND
12Z. FOR NOW, I ONLY EXPECT VISIBILITIES TO BE REDUCED TO LESS THAN
1 MILE, SO A FOG ADVISORY DOES NOT SEEM WARRANTED, BUT SHOULD BE
WATCHED AND MONITORED. THIS FOG AND THE LOW CLOUDS WILL DELAY THE
DAY TIME HEATING, BUT THE WARM ADVECTION WILL WIN OUT LATER THIS
MORNING. THE WARMEST TEMPERATURES WILL BE NEAR THE COLORADO
BORDER, WHERE A LEE SIDE TROUGH WILL EXIST. MID 80S SHOULD BE
REALIZED THERE, WHILE COOLER HIGH PRESSURE TO OUR EAST WILL RESULT
IN HIGH TEMPERATURES IN THE MID 70S NEAR HAYS AND LACROSSE. THE
CLOUDS WILL LINGER OVER OUR EASTERN ZONES THROUGH MUCH OF THE
AFTERNOON. LIGHT AND VARIABLE WINDS EARLY TODAY WILL BECOME FROM
THE SOUTH AT ONLY THE 10 TO 12 MPH RANGE THIS AFTERNOON. I HAVE
CHOSE TO FOLLOW THE HRRR AND RUC MODELS, WHICH KEEP ANY PRECIPITATION
TODAY TO OUR SOUTH. OF NOTE HOWEVER, ARE BOTH THE HIRESW-NMM AND
THE HIRESW-ARW MODELS WHICH BOTH BRING LIGHT PRECIPITATION TO OUR
SOUTHERN CWA THIS AFTERNOON, BASICALLY SOUTH OF HIGHWAY 50.
I EXPECT NEARLY CLOUD-FREE SKIES OVERNIGHT WITH LIGHT SOUTH WINDS AT
6 TO 8 MPH. THE TEMP/DEWPOINT SPREAD IS EXPECTED TO BE GREATER
TONIGHT, SO I DON`T EXPECT AS MUCH FOG OR STRATUS. THERE COULD BE
SOME 3 TO 5SM FOG, ESPECIALLY IN OUR EAST, BUT I DON`T THINK THIS
IS WORTH MENTIONING. MINIMUM TEMPERATURES SHOULD BE SIMILAR TO
THIS MORNING, RANGING FORM THE LOWER 60S NORTH OF I-70 TO THE MID
60S IN THE BARBER AND COMANCHE COUNTY AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 322 AM CDT TUE SEP 16 2014
MEDIUM RANGE MODELS INDICATE A NORTHWESTERLY FLOW ALOFT PREVAILING
ACROSS THE WESTERN HIGH PLAINS WEDNESDAY AS UPPER LEVEL RIDGING
SLOWLY EDGES EASTWARD ACROSS THE INTERMOUNTAIN WEST INTO THE WESTERN
HIGH PLAINS. THIS WILL LEND TO DRIER CONDITIONS ACROSS MUCH OF
WESTERN KANSAS EARLY IN THE PERIOD. HOWEVER, ISOLATED THUNDERSTORMS
CANNOT BE RULED OUT ACROSS PORTIONS OF CENTRAL AND SOUTH CENTRAL
KANSAS WEDNESDAY NIGHT AS A SURFACE LOW BECOMES MORE ORGANIZED
ACROSS WESTERN KANSAS. A NEAR STATIONARY FRONTAL BOUNDARY IS
PROJECTED TO EXTEND EAST-SOUTHEAST OFF THE SURFACE LOW ACROSS
SOUTHERN KANSAS PROVIDING INCREASED CONVERGENCE. ALONG WITH A
STRONGER FLOW ALOFT, STEEPENING LOW/MID LEVEL LAPSE RATES AND
INCREASED INSTABILITY MAY BE ENOUGH TO SUPPORT THUNDERSTORM
DEVELOPMENT IN THE VICINITY OF THE BOUNDARY WEDNESDAY EVENING INTO
EARLY THURSDAY MORNING. OTHERWISE, DRIER CONDITIONS WILL PREVAIL
ACROSS WESTERN KANSAS THROUGH THURSDAY NIGHT AS THE UPPER LEVEL
RIDGE TRANSITIONS ACROSS THE WESTERN HIGH PLAINS INTO THE CENTRAL
PLAINS.
MORE WIDESPREAD RAINFALL WILL BE POSSIBLE ACROSS WESTERN AND
CENTRAL KANSAS LATE FRIDAY INTO SATURDAY AS THE REMNANTS OF
TROPICAL STORM ODILE ARE PROJECTED TO LIFT NORTHEAST ACROSS THE
DESERT SOUTHWEST THURSDAY ON THE BACKSIDE OF THE UPPER LEVEL RIDGE
SHIFTING EASTWARD INTO THE CENTRAL PLAINS. THE REMNANTS WILL LIFT
FURTHER NORTHEAST INTO THE HIGH PLAINS OF EXTREME EASTERN COLORADO
AND WESTERN KANSAS FRIDAY. MEANWHILE, AN UPPER LEVEL SHORTWAVE
TROUGH IS EXPECTED TO SWING EASTWARD ACROSS THE NORTHERN PLAINS
FRIDAY NIGHT INTO SATURDAY SENDING AN ATTENDANT COLD FRONT SURGING
SOUTHEASTWARD INTO WESTERN AND CENTRAL KANSAS WHILE ADDITIONAL
MOISTURE POOLS AHEAD OF THE APPROACHING FRONT WITHIN A
SOUTHEASTERLY UPSLOPE FLOW. AS A RESULT, SHOWERS AND ISOLATED
THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
WITH THE ONSET OF PRECIP TOWARD FRIDAY AFTERNOON/EVENING. SHOWERS
AND ISOLATED THUNDERSTORMS ARE EXPECTED TO SPREAD EASTWARD INTO
CENTRAL KANSAS LATE FRIDAY NIGHT INTO SATURDAY. BASED ON PW
VALUES AND QPF FIELDS, SOME AREAS COULD SEE IN EXCESS OF ONE HALF
INCH OF RAINFALL BY EARLY SATURDAY MORNING WITH HIGHER AMOUNTS
FURTHER TO THE EAST WHERE INCREASED MOISTURE WILL BE MORE READILY
AVAILABLE.
ABOVE NORMAL TEMPERATURES ARE LIKELY WEDNESDAY AS A SURFACE LOW
DEEPENS ACROSS THE HIGH PLAINS ENHANCING AN ALREADY PREVAILING
SOUTHERLY FLOW INTO WESTERN KANSAS. THE GFS/ECMWF ARE IN FAIR
AGREEMENT SHOWING H85 TEMPERATURES CLIMBING A LITTLE ABOVE 20C
ACROSS CENTRAL KANSAS TO NEAR 25C CLOSER TO THE COLORADO BORDER IN
SOUTHWEST KANSAS. WITH MODEL SOUNDINGS INDICATING STEEP LOW LEVEL
LAPSE RATES BY WEDNESDAY AFTERNOON, LOOK FOR HIGHS WELL UP INTO
THE 80S(F) WITH NEAR 90F IN SOME LOCATIONS. WARM AIR ADVECTION
WILL CONTINUE THURSDAY AS THE SOUTHERLY FLOW PERSISTS RAISING
HIGHS A FEW DEGREES WITH A FEW MORE LOWER 90S(F) POSSIBLE.
SLIGHTLY LOWER HIGH TEMPERATURES CAN BE EXPECTED FRIDAY AS CLOUD
COVER BECOMES MORE WIDESPREAD WITH AREAS OF PRECIP POSSIBLE AS
EARLY AS FRIDAY AFTERNOON.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 648 PM CDT MON SEP 15 2014
MVFR CIGS WILL LOWER TO IFR BETWEEN 08-12Z WITH SOME AREAS OF FOG
AT KGCK AND KDDC UNDER LIGHT NORTHEAST TO LIGHT AND VARIABLE
WINDS. AT KHYS IFR CIGS ARE FORECAST BY 09-12Z. CIGS SHOULD
IMPROVE TO VFR AFTER 18Z AS SOUTH TO SOUTHWEST WINDS INCREASE
BEHIND A SURFACE RIDGE OF HIGH PRESSURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 64 89 63 / 10 10 0 10
GCK 82 61 89 62 / 10 0 0 10
EHA 86 62 89 62 / 10 0 0 10
LBL 83 63 90 64 / 10 0 0 10
HYS 73 61 84 63 / 10 10 0 20
P28 79 66 89 63 / 10 10 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...JJOHNSON
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
120 AM CDT TUE SEP 16 2014
...UPDATED FOR THE SHORT TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 114 AM CDT TUE SEP 16 2014
THIS MORNING WILL BE PLAGUED BY WIDESPREAD FOG AND LOW CEILINGS.
THERE IS ABUNDANT MOISTURE AT THE LOWER LAYERS AND THE LIGHT WINDS
WILL ALLOW THE TEMP/DEWPOINT DEPRESSION TO WITHER TO 1 TO 2 DEGREES
APART. THIS FOG SHOULD START IN OUR NORTHWEST ZONES FIRST NEAR
SYRACUSE AND SCOTT CITY, AND SPREAD SOUTHEASTWARD BETWEEN 09Z AND
12Z. FOR NOW, I ONLY EXPECT VISIBILITIES TO BE REDUCED TO LESS THAN
1 MILE, SO A FOG ADVISORY DOES NOT SEEM WARRANTED, BUT SHOULD BE
WATCHED AND MONITORED. THIS FOG AND THE LOW CLOUDS WILL DELAY THE
DAY TIME HEATING, BUT THE WARM ADVECTION WILL WIN OUT LATER THIS
MORNING. THE WARMEST TEMPERATURES WILL BE NEAR THE COLORADO
BORDER, WHERE A LEE SIDE TROUGH WILL EXIST. MID 80S SHOULD BE
REALIZED THERE, WHILE COOLER HIGH PRESSURE TO OUR EAST WILL RESULT
IN HIGH TEMPERATURES IN THE MID 70S NEAR HAYS AND LACROSSE. THE
CLOUDS WILL LINGER OVER OUR EASTERN ZONES THROUGH MUCH OF THE
AFTERNOON. LIGHT AND VARIABLE WINDS EARLY TODAY WILL BECOME FROM
THE SOUTH AT ONLY THE 10 TO 12 MPH RANGE THIS AFTERNOON. I HAVE
CHOSE TO FOLLOW THE HRRR AND RUC MODELS, WHICH KEEP ANY PRECIPITATION
TODAY TO OUR SOUTH. OF NOTE HOWEVER, ARE BOTH THE HIRESW-NMM AND
THE HIRESW-ARW MODELS WHICH BOTH BRING LIGHT PRECIPITATION TO OUR
SOUTHERN CWA THIS AFTERNOON, BASICALLY SOUTH OF HIGHWAY 50.
I EXPECT NEARLY CLOUD-FREE SKIES OVERNIGHT WITH LIGHT SOUTH WINDS AT
6 TO 8 MPH. THE TEMP/DEWPOINT SPREAD IS EXPECTED TO BE GREATER
TONIGHT, SO I DON`T EXPECT AS MUCH FOG OR STRATUS. THERE COULD BE
SOME 3 TO 5SM FOG, ESPECIALLY IN OUR EAST, BUT I DON`T THINK THIS
IS WORTH MENTIONING. MINIMUM TEMPERATURES SHOULD BE SIMILAR TO
THIS MORNING, RANGING FORM THE LOWER 60S NORTH OF I-70 TO THE MID
60S IN THE BARBER AND COMANCHE COUNTY AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 342 PM CDT MON SEP 15 2014
THE EXTENDED PERIOD CAN BE CHARACTERIZED BY WARMING CONDITIONS
THROUGH THE BEGINNING OF THE WEEKEND WITH SOME VERY SMALL CHANCE OF
PRECIPITATION AROUND TUESDAY NIGHT OR WEDNESDAY, BUT BETTER CHANCES
BY FRIDAY NIGHT OR SATURDAY.
A MEAN 582 DM 500 MB HEIGHT RIDGE WILL BUILD ACROSS THE CENTRAL
PLAINS BY MIDWEEK. WITH NORTHWEST FLOW ACROSS THE AREA IN THE
MEANTIME, SUBSIDENCE BUILDING THE 850 HIGH OFF TO THE SOUTHEAST, A
WEAK BOUNDARY LAYER MOISTURE TRANSPORT SIGNAL DEVELOPS ACROSS
CENTRAL KANSAS BY A MOST OF THE MODELS. THE MODELS ARE MIXED AT HOW
ROBUST THEY ARE SUGGESTING PRECIPITATION DEVELOPMENT. SOME
FRONTOGENESIS IS PRESENT BY VERY WEAK MID LEVEL DEFORMATION FIELD
AND THE SIGNAL SUGGESTS PRECIPITATION TO BE MORE OF AN EASTERN
KANSAS OR NEBRASKA EVENT. HOWEVER AS THE POTENTIAL PRECIPITATION
PATTERN MATURES, SMALL POPS WERE ADDED BY WEDNESDAY NIGHT MAINLY
EAST OF HIGHWAY 183.
A BETTER CHANCE FOR PRECIPITATION IS IN THE SATURDAY TIMEFRAME. A
WEST COAST TROUGH WILL BECOME REINFORCED AIDING THE SPREAD OF
RESIDUAL TROPICAL MOISTURE INTO THE CENTRAL PLAINS REGION FROM A
DECAYING TROPICAL DISTURBANCE ACROSS MEXICO. THE GFS AND ECMWF ARE
BOTH SHOWING A DECENT PATTERN FOR RAIN AND SCATTERED THUNDERSTORMS
DUE TO INCREASING MID LEVEL VORTICITY ACROSS THE CENTRAL HIGH
PLAINS. ALONG WITH THE INCREASED MID LEVEL MOISTURE, OVERCAST
CONDITIONS SHOULD DEVELOP DRIVING DAYTIME TEMPERATURES DOWNWARD
BACK INTO THE 70S BY THE MONDAY IF NOT EARLIER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 648 PM CDT MON SEP 15 2014
MVFR CIGS WILL LOWER TO IFR BETWEEN 08-12Z WITH SOME AREAS OF FOG
AT KGCK AND KDDC UNDER LIGHT NORTHEAST TO LIGHT AND VARIABLE
WINDS. AT KHYS IFR CIGS ARE FORECAST BY 09-12Z. CIGS SHOULD
IMPROVE TO VFR AFTER 18Z AS SOUTH TO SOUTHWEST WINDS INCREASE
BEHIND A SURFACE RIDGE OF HIGH PRESSURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 64 89 63 / 10 10 10 10
GCK 82 61 89 62 / 10 0 10 10
EHA 86 62 89 62 / 10 0 0 10
LBL 83 63 90 64 / 10 0 0 10
HYS 73 61 84 63 / 10 10 10 20
P28 79 66 89 63 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...RUSSELL
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS JACKSON KY
216 AM EDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 216 AM EDT TUE SEP 16 2014
COLD FRONT IS NOW DROPPING SOUTH INTO NORTHERN KENTUCKY. ISOLATED TO
SCATTERED SHOWERS CONTINUE TO DEVELOP AND SPREAD EAST JUST AHEAD OF
THIS BOUNDARY. GIVEN THE INCREASING TREND OF THESE SHOWERS...HAVE
OPTED TO INCREASE PRECIPITATION COVERAGE A BIT. MODELS CONTINUE TO
STRUGGLE WITH THIS SYSTEM AND SUGGEST VERY LITTLE GOING ON OVERNIGHT.
HOWEVER...GIVEN THIS IS CERTAINLY NOT THE CASE...OPTED TO STRAY AWAY
FROM THE MODELS THROUGH THE REMAINDER OF THE NIGHT AND INTO TOMORROW
MORNING. JUST BEHIND THE FRONT...ATTENTION WILL TURN TO A PERIOD OF
DRIZZLE OR LIGHT RAIN AS LOW CLOUDS BUILD IN BEHIND THE BOUNDARY.
THIS WILL ALL SLOWLY SHIFT SOUTH THROUGH THE REST OF THE NIGHT AND
INTO TUESDAY. FORECAST HAS BEEN UPDATED TO REFLECT THESE CHANGES.
UPDATE ISSUED AT 939 PM EDT MON SEP 15 2014
FIRST BATCH OF SHOWERS REALLY DISSIPATED UPON ARRIVAL. HOWEVER...A
SECOND SURGE HAS PUSHED INTO NORTH CENTRAL KENTUCKY AND IS HOLDING
TOGETHER A BIT BETTER. THIS AREA OF SHOWERS WILL SWING SOUTH ACROSS
AREAS MAINLY NORTH OF THE HAL ROGERS PARKWAY. THIS WILL PROVIDE A
PERIOD OF CATEGORICAL POPS FOR THE AREA OVER THE NEXT 2 TO 4 HOURS.
IT LOOKS LIKE COVERAGE SHOULD BACK OFF AGAIN TOWARDS MIDNIGHT UNTIL
THE COLD FRONT STARTS TO PUSH SOUTH TOWARDS 4 AM. HOWEVER...AT THIS
TIME...ISOLATED COVERAGE AT BEST IS STILL ANTICIPATED WITH THE ACTUAL
FRONT. UPDATED FORECAST HAS BEEN SENT.
UPDATE ISSUED AT 813 PM EDT MON SEP 15 2014
SHOWERS ACROSS THE SOUTH HAVE ENDED...BUT STILL WATCHING A COMPLEX OF
SHOWERS MOVING ACROSS NORTH CENTRAL KENTUCKY AND WILL BE SPREADING
ACROSS AREAS NORTH OF THE MOUNTAIN PARKWAY OVER THE COMING 2 TO 4
HOURS. THIS ACTIVITY WILL MOVE ON THROUGH AND THEN WE WILL WAIT ON
THE COLD FRONT TO MOVE INTO THE AREA LATER TONIGHT...BRINGING THE
THREAT OF AN ISOLATED SHOWER BACK TO THE AREA BY DAWN. ADJUSTED
HOURLY POPS TO ACCOUNT FOR THESE TRENDS. OTHERWISE...NO OTHER CHANGES
WARRANTED AT THIS TIME.
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 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 216 AM EDT TUE SEP 16 2014
A COLD FRONT WILL MARCH SOUTH ACROSS EASTERN KENTUCKY THIS MORNING
THROUGH THE DAYTIME HOURS. WHILE VFR CIGS WILL START OFF THE
PERIOD...AS THE FRONT PUSHES THROUGH LATER ON...IFR/MVFR CIGS WILL
DEVELOP AND LAST WELL INTO THE DAY TOMORROW. IN FACT...NOT ALL THAT
CONFIDENT WE WILL LOSE THE MVFR CIGS TOMORROW ESPECIALLY ACROSS THE
SOUTH. FOR NOW WILL GO PESSIMISTIC WITH THE SKY COVER. WE MAY FINALLY
LOSE THE LOW CLOUDS BY LATE IN THE DAY OR EVENING AS SKIES CLEAR FOR
TOMORROW NIGHT. THIS MAY IN TURN SET THE STAGE FOR LOCALLY DENSE FOG
TUESDAY NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1150 PM CDT Mon Sep 15 2014
.UPDATE...
Issued at 651 PM CDT MON SEP 15 2014
Updated the grids, to reflect slight tsra chance all locations
through the evening. Greatest surface based instability is west of
I-55. However using Best LI computation off the RUC depicts
adequate elevated instability all locales. Doesn`t mean it will
amount to much. But will have it covered. Kept coverage wording
as isolated for now. Will have to tweak the winds a bit. Temps and
dew points in decent shape. Added mention of patchy light drizzle
post front aft 06z, as 1000-925mb rh really picks up. This lines
up with what our neighboring offices to our North and West have as
well in the grid depiction.
&&
.SHORT TERM...(Tonight through Wednesday night)
Issued at 116 PM CDT MON SEP 15 2014
Radar shows light shower activity to our north, associated with
the front, and to our south, associated with some warm air
advection that occurred ahead of the front. The front will move in
this evening, and thru the FA tonight. The HRR has been perhaps
the best model of the short term pcpn, particularly this morning,
but all more or less shrivel up the frontal precip as it moves
south and into our area. We`ll still maintain a 20 pop fa-wide,
and the northeast could see a few percentage points higher, but
we`ll monitor that in the near term and made adjustments
accordingly.
After fropa, drier air wedges in and down the column tmrw,
particularly late tmrw-tmrw night. This occurs as surface high
pressure works in and across the Ohio valley. By Wed., the high
has shifted east and some return flow warm air advection on its
backside introduces a small/slgt chance mention pops in the
Ozarks. This has been a fairly consistent signal and given the
extent of precip this morning from a similar signal, we`ll
continue to carry some low pops for Semo to cover it, Wed-Wed
night.
.LONG TERM...(Thursday through Monday)
Issued at 116 PM CDT MON SEP 15 2014
The first half of the long term portion of the forecast will see a
trof to the east and a ridge to the west, with our area becoming
more and more influenced by the ridge to the west. This will
result in rising heights and a subsequent warming of the profile.
Highs in the 70s earlier in the week will rebound to the 80s by
the weekend, and lows will do similarly, moving from the 50s to
the 60s in like manner and timing.
Dry weather is forecast into the first half of the weekend, but as
the surface high moves east, return flow kicks in ahead of a
developing frontal system. Jet energy spilling across the High
Plains will lower heights and help drive cylcogenesis and an
eventual front into and through our area, with fairly consistent
member signalling for pops coming in as early as Sat night, and
fropa Sunday. This should result in a return to 70s/50s by early
next week.
&&
.AVIATION...
Issued at 1149 PM CDT MON SEP 15 2014
The drier and faster solution proposed by the GFS numerical
guidance appears to be occuring at this time. With that in mind,
began the forecast period with IFR conditions along and immediately
behind the cold front. Rapidly improve conditions after 12z with
VFR conditions dominating the rest of the forecast.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...CN
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
342 AM EDT TUE SEP 16 2014
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION DURING THE EARLY MORNING
HOURS. HIGH PRESSURE WILL RETURN LATER TODAY AND REMAIN THROUGH
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
07 UTC SFC ANALY PLACES WK CDFNT MVG E OF THE THE PTMC HIGHLANDS
ATTM. PVA GNLY CONFINED TO PA/NY...AND THATS WHERE A SWATH OF SHRA
CAN BE FOUND ON RGNL RDR. LIGHTER SHRA S OF PIT...BUT W/O UPA
SUPPORT DOUBT THAT MSTR CAN MAKE IT OVER THE MTNS. WAA AHD OF FNT
RESPONSIBLE FOR A PD OF LWR CLDS. HV HAD DVLPG SHRA E OF THE
BLURDG IN RESPONSE TO THIS FEATURE. HRRR MODELED THIS FAIRLY WELL.
IF ANY PLACE HAS POTL TO SEE SOME PVA/JETMAX/WAA INTERACTION...
ITS MD NE OF THE PTMC RIVER. HV CHC POPS THERE...AS WELL AS ALONG
THE ALLEGHENY FRONT FOR LIFT FM UPSLOPE. THE REST OF THE I-95
CRRDR /DC TO EZF/ COVERED BY SCHC POPS DUE TO ISOL NATURE OF PCPN.
AFTER SUNRISE...THE CDFNT SHUD BE MVG ACRS THE DELMARVA...MARKING
CLRG SKIES AND THE END OF ANY SPRINKLES/SHRA. PRES RISES AND CAA
SHUD PROMOTE GUSTY WINDS...ALTHO THEY MAY NOT BE QUITE AS STRONG AS
THEY WERE LOOKING LIKE YDA. SOME GDNC SUGGESTING THERE MAY BE A FEW
MORE SHRA IN THE MTNS. WL KEEP ADDTL DIURNAL CU...BUT OPPORTUNITES
FOR ANY ADDTL PCPN LOOK MEAGER /TOO LMTD TO INCL IN GRID ATTM/.
LTST GDNC IN GOOD SYNCH W/ GOING MAXT FCST. HV BLENDED IT IN...ALONG
W/ BIAS CORRECTED GIDS TO ACCT FOR CONTD WARM BIAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIPRES WL BE BLDG ACRS THE CWFA TNGT THRU TMRW NGT. HWVR...MSTR FM
THE STALLED FNT WL BE ACRS THE CAROLINAS. FURTHER...H5 HGT PTTN
SLIGHTLY TROFFY. THEREFORE...MAY NOT HV CLEAR/CALM CONDS THRUT. HV
PDS OF PT-MOCLDY SKIES...SPCLY ACRS CENTRL VA. WL BE KEEPING FCST
DRY THRU THE PD SINCE FORCING MINIMAL.
IN TERMS OF TEMPS...HV GNLY GONE ON THE COOL SIDE SUPPORTED BY CAA
AND UPR TROF AXIS. WHERE MOS DIVERGED...AM CLOSER TO MAV.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
NORTHERLY FLOW WILL CONTINUE THURSDAY AS HIGH PRESSURE MOVES ACROSS
THE THE NRN GREAT LAKES AND ONTARIO. A UPPER LEVEL DISTURBANCE WILL
CROSS THE MID-ATLANTIC THURSDAY AND CLOUDS WILL INCREASE FROM NORTH
TO SOUTH THROUGHOUT THE DAY. DRY NORTHERLY FLOW AT THE SFC WILL
CONTINUE TO ADVECT LOW RH INTO THE REGION LEADING TO A DRY COLUMN.
ISO SHOWERS ARE POSSIBLE BUT CONFIDENCE IS LOW AT THIS TIME AND WILL
CONTINUE THE DRY FORECAST THURSDAY. FCST MAX TEMPS WILL RANGE
FROM THE UPPER 60S IN THE MTNS TO MID TO HIGH 70S ALONG I-95 AND
EAST.
HIGH PRESSURE WILL STRENGTHEN ACROSS THE AREA INTO THE WEEKEND AS IT
WEDGES DOWN THE EASTERN SEABOARD. ONSHORE FLOW SATURDAY MAY LEAD TO
LOW STRATUS AS MARINE AIR MOVES INTO THE REGION. A SHORTWAVE TROUGH
WILL APPROACH THE MID-ATLANTIC SUNDAY WHILE HIGH PRESSURE WEAKENS.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE SUNDAY NIGHT THROUGH
MONDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT WILL PASS THROUGH THE TERMINALS DURING THE PREDAWN HRS.
A COUPLE SHOWERS CANNOT BE RULED OUT...BUT MOST AREAS WILL BE DRY.
WX RESTRICTIONS NOT IN TAFS DUE TO WDLY SCT NATURE OF PCPN.
THE BIGGER CONCERN FOR THE MRNG PUSH WILL BE CIGS. MVFR CONDS
ADVCG EWD AHD OF THE FNT. ITS LOOKING LIKE ALL TERMINALS WL BE
AFFECTED PRIOR TO FROPA. TAF AMD COMING. DO NOT FORSEE IFR.
FURTHER... CIGS SHUD LIFT TO VFR DURING THE PUSH.
HIGH PRESSURE WILL RESIDE ACROSS THE REGION FOR THE REST OF THE
VALID PERIOD. VFR CONDITIONS EXPECTED. ONSHORE FLOW MAY LEAD TO
REDUCED CIGS/VSBYS SATURDAY.
&&
.MARINE...
A COLD FRONT WILL PASS THROUGH THE WATERS DURING THE ELY MRNG HRS.
AHD OF THE FNT...SLY CHANNELING HAS BROUGHT 20-25 KT GUSTS TO
TPLM2. WL HV A LULL IN WNDS INVOF CFP...WHICH IS WHERE WE ARE NOW.
POST-FROPA...NWLY FLOW WL MIX BETTER INVOF PRES RISES. MARGINAL
CASE OF 20 KT GUSTS. SCA IN EFFECT ATTM FOR MAIN CHANNEL OF THE
BAY AND TANGIER SOUND. SCA FOR ALL WATERS BEHIND THE FRONT...WHICH
WL BEGIN AT 9AM.
HIGH PRESSURE WILL BUILD ACROSS THE WATERS TONIGHT AND RESIDE
THROUGH THE WEEKEND. N-NE FLOW ON THE WATERS IS EXPECTED.
&&
.TIDES/COASTAL FLOODING...
A COLD FRONT WILL CROSS THE WATERS EARLY THIS MORNING. SHOULD HAVE
NW WINDS CAUSING BLOW OUT CONDITIONS BY THE TIME THE NEXT HIGH TIDE
ARRIVES. WATER MAY BE SLIGHTLY ELEVATED WRT ASTRO NORMS...BUT NO
PROBLEMS ANTICIPATED AT THIS TIME.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 5 PM EDT THIS
AFTERNOON FOR ANZ530-531-535>542.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR
ANZ532>534-543.
&&
$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...HAS
AVIATION...HTS/HAS
MARINE...HTS/HAS
TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 AM EDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE SEP 16 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE AND ASSOC JET
MAX MOVING THROUGH NRN ONTARIO WHICH HAS SUPPORTED A CLUSTER OF SHRA
ALONG COLD FRONTAL BOUNDARY OVER NW ONTARIO AS NOTED ON CANADIAN
RADAR MOSIAC. CLEAR SKIES AND LIGHT WINDS UNDER SFC HIGH PRES RIDGE
HAVE ALLOWED FOR MIN TEMPS TO DROP NEAR OR BLO THE FREEZING MARK FOR
MANY OF THE TYPICAL INTERIOR COLD SPOT LOCATIONS ACROSS UPPER MI
EARLY THIS MORNING.
TODAY...PLENTY OF SUNSHINE THIS MORNING WILL GIVE WAY TO INCREASING
CLOUDS LATE IN THE AFTERNOON AS A COLD FRONT SAGS SOUTHWARD THROUGH
LAKE SUPERIOR. MODELS INDICATE THAT ANY LIGHT PCPN ASSOCIATED WITH
THE FRONT AND ASSOC 900-800 MB FGEN SHOULD STAY NORTH OF THE
KEWEENAW UNTIL EVENING. OTHERWISE...EXPECT TEMPERATURES TO REBOUND
CLOSER TO SEASONAL AVERAGES WITH HIGHS IN THE MID 60S AND PERHAPS
EVEN REACHING UPPER 60S FOR A FEW DOWNSLOPING LOCATIONS OVER NCNTRL
UPPER MI IN DEVELOPING WSW FLOW AHEAD OF THE FRONT.
TONIGHT...THE COLD FRONT WILL SAG SOUTH INTO MAINLY THE NW AND ERN
CWA BY LATE EVENING. MODELS SHOW THAT THE BEST MOISTURE WILL BE N OF
THE FRONT WITH THE BEST FORCING/Q-VECT CONV TO BE OVER NW AND ERN
CWA LATE TONIGHT AHEAD OF A SHORTWAVE MOVING ACROSS WRN ONTARIO AND
IN THE RIGHT ENTRANCE REGION OF ASSOC 100+ KT 3H JET MAX MOVING INTO
WRN QUEBEC. WILL MAINTAIN SLIGHT CHC TO LOW CHC POPS FOR SHRA OVER
MAINLY THE KEWEENAW AND FAR NE CWA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE SEP 16 2014
A COLD FRONT THAT MOVED INTO THE THE CWA TUE EVENING WILL HAVE A
WNW-ESE ORIENTATION OVER THE CENTRAL CWA AT 12Z WED...AND WILL MOVE
S OF THE CWA BY WED EVENING. BEST MOISTURE WILL BE N OF THE FRONT
AND BEST FORCING WILL BE OVER THE NRN CWA LATE TUE NIGHT INTO WED
MORNING AS AN UPPER TROUGH MOVES ACROSS THE AREA. A SFC HIGH WILL
MOVE IN QUICKLY BEHIND THE UPPER TROUGH/COLD FRONT...USHERING IN DRY
AND COLDER AIR. WHAT THIS MEANS FOR PRECIP CHANCES IS THAT THE
GREATEST POPS WILL BE OVER THE NRN CWA WED MORNING WITH THE UPPER
TROUGH ENERGY. PRECIP CHANCES ARE LOWER TO THE S...BUT SLIGHT CHANCE
TO LOW END CHANCE POPS WILL FOLLOW THE POST-FRONTAL MOISTURE S
THROUGH THE AFTERNOON. HIGH TEMPS WILL RANGE FROM AROUND 50 OVER NRN
UPPER MI NEAR LAKE SUPERIOR TO AROUND 60 OVER THE SCENTRAL.
THE SFC HIGH CENTER WILL MOVE ACROSS FAR NERN LAKE SUPERIOR WED
NIGHT INTO THU MORNING. PREVIOUS MODEL RUNS SHOWED A NARROW AREA OF
WAA AND GREATER MOISTURE OVER THE WRN CWA...BUT NEWEST RUNS SHOW
THAT BEING WELL SW OF THE CWA. THEREFOR...WHILE ERN UPPER MI SHOULD
STILL BE THE COLDEST DUE TO THE PROXIMITY TO THE HIGH AND COLDEST
AIRMASS...THE WRN CWA COULD ALSO SEE NEAR FREEZING TEMPS. LOOKS LIKE
FROST IS A GOOD POSSIBILITY ACROSS MUCH OF INLAND UPPER MI.
LOW LEVEL RETURN FLOW WILL BEGIN ON THU BETWEEN THE DEPARTING SFC
HIGH AND A BROAD TROUGH MOVING INTO THE WRN PLAINS. NO PRECIPITATION
IS EXPECTED THU DUE TO LINGERING DRY AIR. HIGH TEMPS WILL BE 1-2
DEGREES WARMER THAN WED.
WAA/ISENTROPIC ASCENT REALLY INCREASE LATE THU NIGHT AND FRI AS THE
SFC HIGH TO THE E SLOWS AND THE TROUGH TO THE W ACCELERATES
EASTWARD. THE WAA AND POSSIBLY SOME SHORTWAVE ENERGY WILL LIKELY
LEAD TO PRECIP ACROSS MUCH OF THE CWA FRI INTO FRI NIGHT. MODELS ARE
IN GOOD AGREEMENT THROUGH FRI...BUT BECOME MUCH HARDER TO USE FRI
NIGHT INTO SAT DUE /AT LEAST PARTLY/ TO WITH PHASING OF REMNANTS OF
HURRICANE ODILE WITH THE EXISTING TROUGH. WHILE MODELS DO ALL SHOW A
GOOD AMOUNT OF QPF FOR SAT...THEY DO NOT AGREE WELL IN THE FEATURES
CAUSING THE PRECIP. WHILE POPS WILL REMAIN HIGH ON SAT...SIGNIFICANT
UNCERTAINTY STILL EXISTS. WILL KEEP THUNDER CHANCES GOING FOR FRI
AFTERNOON THROUGH SAT EVENING...BUT AM NOT OVER CONCERNED ABOUT
HEAVY RAIN UNLESS REMNANTS OF ODILE END UP MOVING INTO THE AREA
/WHICH IS HIGH UNCERTAIN/. WARMEST CONDITIONS OF THE PERIOD ARE
EXPECTED ON SAT AS 850MB TEMPS INCREASE TO GREATER THAN 15C.
MUCH COLDER AIR MOVES IN WITH NW FLOW SUN AND MON...EVEN BRINGING
THE POSSIBILITY OF LAKE EFFECT RAIN SHOWERS BOTH DAYS. AGREE WITH
PREVIOUS SHIFT THAT ECMWF SHOULD BE SET ASIDE BECAUSE IT IS A COLD
OUTLIER.
&&
.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 455 AM EDT TUE SEP 16 2014
EXPECT WSW WINDS TO 25 KTS THROUGH EARLY AFTERNOON AHEAD OF A COLD
FRONT APPROACHING FROM ONTARIO. WINDS WILL DIMINISH AS FRONT MOVES
OVERHEAD TONIGHT BUT THEN INCREASE TO UP TO 25 KTS FROM THE
NORTHEAST IN THE WAKE OF THE COLD FRONT ON WEDNESDAY...MAINLY OVER
WRN LAKE SUPERIOR. 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. WINDS
WILL LIKELY DIMINISH ON SATURDAY AS LOW PRES TROUGH FROM THE PLAINS
MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR MIZ002-
004-005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 AM EDT TUE SEP 16 2014
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE
.SYNOPSIS...
ISSUED AT 319 AM EDT TUE SEP 16 2014
AN AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION TODAY FROM THE
WEST. THIS SYSTEM WILL HELP TO CREATE AREAS OF DENSE FOG THIS
MORNING. THE FOG WILL DISSIPATE LATER THIS MORNING GIVING WAY TO
MOSTLY SUNNY SKIES AND BELOW NORMAL TEMPERATURES. A WEAK COLD
FRONT WILL SLIP SOUTH OF THE REGION WEDNESDAY NIGHT. THEN A VERY
STRONG HIGH PRESSURE SYSTEM WILL BUILD DOWN FROM THE NORTH FOR THE
END OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 319 AM EDT TUE SEP 16 2014
THE MAIN CHALLENGE DEALS WITH THE POTENTIAL FOR DENSE FOG EARLY
THIS MORNING. OVERALL IT LOOKS LIKE MOST LOCATIONS WILL SEE DENSE
FOG THIS MORNING. AS A RESULT I ISSUED A DENSE FOG ADVISORY.
THICK FOG ALREADY EXISTS IN PLACES...ESPECIALLY NORTH OF
INTERSTATE 96 AS OF 3 AM. HRRR RUC SHOWS THE SKIES TEMPORARILY
CLEARING OUT ACROSS SOUTHERN LOWER MI WITH THE THICK FOG BUILDING
SOUTHWARD THROUGH THE REMAINDER OF THE NIGHT. THE FOG IS SHOWN TO
SLOWLY DISSIPATE LATE THIS MORNING. AS A RESULT WITH AN ELEVATED
RISK FOR HAZARDOUS CONDITIONS FOR THE MORNING COMMUTE AND AT BUS
STOPS...I DECIDED THAT AN ADVISORY WOULD BE THE BEST WAY TO GO.
THE REMAINDER OF THE FORECAST IS RELATIVELY QUITE WITH A WEAK DRY
COLD FRONTAL PASSAGE WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 319 AM EDT TUE SEP 16 2014
THE MAIN FOCUS OF THE LONG TERM PORTION OF THE FCST CONTINUES TO BE
THE SYSTEM THAT IS FCST TO MOVE THROUGH THE AREA THIS WEEKEND AND
THE ASSOCIATED PCPN CHCS WITH IT.
WE SHOULD SEE ONE MORE DRY AND QUITE MILD DAY AT THE BEGINNING OF
THE PERIOD ON FRI. THE FAR NW CORNER COULD SEE A LOW CHC OF SOME
RAIN LATE ON FRI AFTERNOON. WE WILL SEE AN UPPER RIDGE IN THE
PROCESS OF WEAKENING AS IT MOVES EAST INTO THE AREA DURING THE DAY
ON FRI. THIS WILL KEEP MOST OF THE AREA DRY. INCREASING SRLY RETURN
FLOW WILL BRING A NICE SURGE OF WARMTH INTO THE AREA.
THE THREAT OF RAIN WILL GRADUALLY INCREASE STARTING FRI NIGHT AND
WILL PEAK ON SAT NIGHT. WE WILL SEE THE INITIAL SFC LOW WITH THE
NEXT FRONT STAY WELL NORTH INTO CANADA...TAKING WITH IT THE BEST LOW
LEVEL JET AND MOISTURE TRANSPORT WITH IT. THE FRONT WILL APPROACH
THE AREA LATE ON SAT AND THEN MOVE THROUGH THE AREA ON SAT NIGHT AND
INTO THE FIRST PART OF SUN. WE COULD SEE ANOTHER VERY MILD DAY ON
SAT IF WE SEE A DECENT AMOUNT OF SUNSHINE AND H850 TEMPS IN THE MID
TEENS C.
THE INTERESTING THING ABOUT THE FRONTAL PASSAGE WILL BE THAT SOME OF
THE MODELS ARE INDICATING THAT SOME REMNANTS FROM THE TROPICAL
SYSTEM ODILE COULD INTERACT WITH THE FRONT. THIS COULD LEAD TO A BIT
MORE RAIN THAN CURRENTLY FCST AS THE MODELS TYPICALLY UNDER FCST THE
AMOUNT OF HEAT AND MOISTURE WITH SYSTEMS OF A TROPICAL ORIGIN THAT
BECOME EXTRA-TROPICAL. THIS WILL BE SOMETHING TO WATCH.
WE SHOULD DRY OUT DURING THE SECOND HALF OF SUN AS WE SEE THE DRY
SLOT MOVE THROUGH THE AREA. WE COULD SEE ONE MORE MILD DAY ON SUN
BEFORE THE COLD CONVEYOR BELT WRAPS INTO THE AREA ON MON. THE MODELS
ARE SHOWING H850 TEMPS DROPPING DOWN CLOSE TO ZERO C ON MON. THERE
IS FAIRLY DECENT AGREEMENT WITH THE STRENGTH AND TIMING OF THIS LOW
AND THE COLD AIR BEHIND IT. WE HAVE ADDED SOME LAKE EFFECT RAIN
SHOWERS FOR MON ALONG THE SHORE WITH AN EXPECTED NNW WIND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 143 AM EDT TUE SEP 16 2014
THE MAIN IMPACT TO AVIATION INTERESTS WITH THE 06Z FCSTS WILL BE
THE FOG/LOW CLOUD TRENDS. SOME PATCHY IFR OCCURRED BEHIND THE AREA
OF RIN THAT MOVED THROUGH IN THE EVENING. WE HAVE SEEN A STRATUS
DECK NOW TAKE SHAPE. THE BACKEDGE OF THIS IS PROGRESSING SE...AND
NOW FOG IS DOMINATING WHERE IT HAS CLEARED OUT. WE HAVE GONE WITH
THE IDEA THAT AS THE INITIAL LOW CLOUDS MOVE OUT...THAT FOG WILL
DEVELOP AND VLIFR LOOKS QUITE POSSIBLE.
THE FOG WILL GRADUALLY MIX OUT/LIFT DURING THE LATE MORNING HOURS.
CONDITIONS SHOULD BECOME VFR AT ALL SITES BY EARLY AFTERNOON WITH
SOME CUMULUS CLOUDS DEVELOPING AS THE LOW LEVEL MOISTURE MIXES OUT.
&&
.MARINE...
ISSUED AT 319 AM EDT TUE SEP 16 2014
MAY END UP WITH WAVES APPROACHING SMALL CRAFT ADVISORY CRITERIA
WEDNESDAY NIGHT INTO THURSDAY AROUND BIG SABLE POINT AS A STRONGER
NORTHEAST FLOW DEVELOPS. WILL CONTINUE TO MONITOR THIS POTENTIAL.
OTHERWISE THE MARINE FORECAST LOOKS QUIET AT THIS POINT.
&&
.HYDROLOGY...
ISSUED AT 319 AM EDT TUE SEP 16 2014
WILL NEED TO MONITOR THE HEAVY RAIN POTENTIAL OVER THE WEEKEND AS
A COLD FRONT MOVES THROUGH AND TAPS TROPICAL MOISTURE. OTHERWISE
NO MAJOR RAIN SYSTEMS EXPECTED THROUGH FRIDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
325 AM EDT TUE SEP 16 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...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE SEP 16 2014
A COLD FRONT THAT MOVED INTO THE THE CWA TUE EVENING WILL HAVE A
WNW-ESE ORIENTATION OVER THE CENTRAL CWA AT 12Z WED...AND WILL MOVE
S OF THE CWA BY WED EVENING. BEST MOISTURE WILL BE N OF THE FRONT
AND BEST FORCING WILL BE OVER THE NRN CWA LATE TUE NIGHT INTO WED
MORNING AS AN UPPER TROUGH MOVES ACROSS THE AREA. A SFC HIGH WILL
MOVE IN QUICKLY BEHIND THE UPPER TROUGH/COLD FRONT...USHERING IN DRY
AND COLDER AIR. WHAT THIS MEANS FOR PRECIP CHANCES IS THAT THE
GREATEST POPS WILL BE OVER THE NRN CWA WED MORNING WITH THE UPPER
TROUGH ENERGY. PRECIP CHANCES ARE LOWER TO THE S...BUT SLIGHT CHANCE
TO LOW END CHANCE POPS WILL FOLLOW THE POST-FRONTAL MOISTURE S
THROUGH THE AFTERNOON. HIGH TEMPS WILL RANGE FROM AROUND 50 OVER NRN
UPPER MI NEAR LAKE SUPERIOR TO AROUND 60 OVER THE SCENTRAL.
THE SFC HIGH CENTER WILL MOVE ACROSS FAR NERN LAKE SUPERIOR WED
NIGHT INTO THU MORNING. PREVIOUS MODEL RUNS SHOWED A NARROW AREA OF
WAA AND GREATER MOISTURE OVER THE WRN CWA...BUT NEWEST RUNS SHOW
THAT BEING WELL SW OF THE CWA. THEREFOR...WHILE ERN UPPER MI SHOULD
STILL BE THE COLDEST DUE TO THE PROXIMITY TO THE HIGH AND COLDEST
AIRMASS...THE WRN CWA COULD ALSO SEE NEAR FREEZING TEMPS. LOOKS LIKE
FROST IS A GOOD POSSIBILITY ACROSS MUCH OF INLAND UPPER MI.
LOW LEVEL RETURN FLOW WILL BEGIN ON THU BETWEEN THE DEPARTING SFC
HIGH AND A BROAD TROUGH MOVING INTO THE WRN PLAINS. NO PRECIPITATION
IS EXPECTED THU DUE TO LINGERING DRY AIR. HIGH TEMPS WILL BE 1-2
DEGREES WARMER THAN WED.
WAA/ISENTROPIC ASCENT REALLY INCREASE LATE THU NIGHT AND FRI AS THE
SFC HIGH TO THE E SLOWS AND THE TROUGH TO THE W ACCELERATES
EASTWARD. THE WAA AND POSSIBLY SOME SHORTWAVE ENERGY WILL LIKELY
LEAD TO PRECIP ACROSS MUCH OF THE CWA FRI INTO FRI NIGHT. MODELS ARE
IN GOOD AGREEMENT THROUGH FRI...BUT BECOME MUCH HARDER TO USE FRI
NIGHT INTO SAT DUE /AT LEAST PARTLY/ TO WITH PHASING OF REMNANTS OF
HURRICANE ODILE WITH THE EXISTING TROUGH. WHILE MODELS DO ALL SHOW A
GOOD AMOUNT OF QPF FOR SAT...THEY DO NOT AGREE WELL IN THE FEATURES
CAUSING THE PRECIP. WHILE POPS WILL REMAIN HIGH ON SAT...SIGNIFICANT
UNCERTAINTY STILL EXISTS. WILL KEEP THUNDER CHANCES GOING FOR FRI
AFTERNOON THROUGH SAT EVENING...BUT AM NOT OVER CONCERNED ABOUT
HEAVY RAIN UNLESS REMNANTS OF ODILE END UP MOVING INTO THE AREA
/WHICH IS HIGH UNCERTAIN/. WARMEST CONDITIONS OF THE PERIOD ARE
EXPECTED ON SAT AS 850MB TEMPS INCREASE TO GREATER THAN 15C.
MUCH COLDER AIR MOVES IN WITH NW FLOW SUN AND MON...EVEN BRINGING
THE POSSIBILITY OF LAKE EFFECT RAIN SHOWERS BOTH DAYS. AGREE WITH
PREVIOUS SHIFT THAT ECMWF SHOULD BE SET ASIDE BECAUSE IT IS A COLD
OUTLIER.
&&
.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 UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR MIZ002-
004-005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
434 AM CDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM CDT TUE SEP 16 2014
THERE ARE PRIMARILY 3 MAIN ISSUES DURING THESE NEXT 24
HOURS...SOME OF WHICH MAY BE BIGGER DEALS THAN OTHERS.
THE FIRST INVOLVES WHETHER OR NOT A POTENTIALLY EXPANSIVE AREA OF
LOWER STRATUS CURRENTLY POSITIONED A FEW COUNTIES SOUTH-SOUTHWEST
OF THE CWA WILL SPREAD NORTHEAST OVER AT LEAST PARTS OF THE CWA
TODAY AND IF SO...HOW MUCH IMPACT TO HIGH TEMPS COULD OCCUR.
COMPARED TO 12-24 HOURS AGO...CONFIDENCE HAS WANED A BIT ON
WHETHER THESE CLOUDS REALLY WILL END UP AFFECTING MUCH OF THE AREA
AND FOR HOW LONG. ISSUE NUMBER 2 CONCERNS THUNDERSTORM CHANCES
TONIGHT...AS ALTHOUGH THE MAJORITY OF THE AREA CARRIES A PRETTY
GOOD CHANCE OF REMAINING STORM FREE...AT LEAST A SLIGHT CHANCE IS
REFLECTED FOR ROUGHLY THE SOUTHEAST 1/4 OF THE CWA POST-MIDNIGHT.
THIRDLY...ALTHOUGH MODELS/GUIDANCE ARE BY NO MEANS
UNANIMOUS...CONCERNS ARE INCREASING FOR AT LEAST SOME COVERAGE OF
POTENTIALLY IMPACTFUL FOG ISSUES LATE TONIGHT/EARLY WED MORNING
ESPECIALLY WITHIN THE WESTERN HALF OF THE CWA AS BREEZES AVERAGE
LIGHT AND SURFACE DEWPOINTS RISE 10+ DEGREES ABOVE CURRENTLY
OBSERVED VALUES...INDICATIVE OF INCREASING LOW LEVEL MOISTURE.
STARTING OFF WITH THE HERE AND NOW AS OF 08Z/3AM...A VERY QUIET
NIGHT CONTINUES ACROSS THE CWA UNDER NEARLY CLOUD-FREE SKIES. AT
THE SURFACE...A ROUGHLY 1025 MILLIBAR RIDGE AXIS IS CENTERED
SQUARELY OVER THE NEB/IA BORDER AREA...PROVIDING NEAR-CALM TO
LIGHT SOUTHEASTERLY BREEZES OF GENERALLY 6 MPH OR LESS. GIVEN THE
FAIRLY IDEAL RADIATIONAL COOLING CONDITIONS...TEMPS HAVE DROPPED
SOMEWHERE INTO THE 40S ACROSS MOST OF THE CWA AS EXPECTED...WITH
EVEN A FEW SITES VERY NEAR THE CWA SUCH AS COLUMBUS/BROKEN BOW AT
LEAST BRIEFLY INTO THE UPPER 30S. AUTOMATED AIRPORT SITES SUGGEST
THAT SOME VERY PATCHY...PRIMARILY LIGHT FOG LIKELY EXISTS OUT
THERE IN A FEW SPOTS...BUT BARRING NOTICEABLE CHANGES ITS
COVERAGE/IMPACT DOES NOT APPEAR WORTHY OF A FORMAL FORECAST
MENTION...WITH SOMEWHAT BETTER CHANCES OF A FEW DECENT VISIBILITY
REDUCTIONS POSSIBLY FOCUSING CLOSER TO THE NEB/IA BORDER. LOOKING
ALOFT TO THE MID-UPPER LEVELS...SHORT TERM MODEL DATA AND WATER
VAPOR IMAGERY INDICATES FAIRLY UNEVENTFUL AND BROAD NORTHWESTERLY
FLOW ALOFT OVER THE CENTRAL PLAINS...STEERED BETWEEN A LARGE SCALE
TROUGH OVER EASTERN CANADA AND A RIDGE EXTENDING NORTHWARD OVER
THE WESTERN CONUS. WAY OFF TO THE SOUTHWEST...TROPICAL STORM ODILE
SLOWLY CHURNS NORTHWEST UP THE BAJA PENINSULA.
LOOKING AHEAD AND STARTING WITH THE VERY SHORT TERM THROUGH
ROUGHLY SUNRISE...THE SURFACE RIDGE AXIS WILL CONTINUE A VERY SLOW
EASTWARD DEPARTURE...ALLOWING LIGHT SOUTH WINDS TO BECOME A BIT
BETTER ESTABLISHED ACROSS MUCH OF THE CWA. AS MENTIONED
ABOVE...THE BIGGEST SHORT TERM MYSTERY INVOLVES THE FATE OF THE
NORTHWEST KS STRATUS DECK...AS LAST FEW 11-3.9 MICRON SATELLITE
FRAMES SHOW ITS LEADING EDGES STARTING TO MAKE A PUSH TOWARD THE
SOUTHWESTERN FRINGES OF THE CWA...BUT UNLIKELY TO POTENTIALLY
INFILTRATE MUCH OF THE LOCAL AREA BEFORE SUNRISE. ALTHOUGH A FEW
PLACES MAY START STEADYING OUT A BIT ON THE TEMP-FALL...MOST OF
THE CWA IS ON TRACK TO REALIZE OVERNIGHT LOWS BETWEEN 41-46
DEGREES.
FOR THE DAYTIME HOURS 12Z-00Z/7AM-7PM...THE FORECAST REMAINS DRY
AS AM NOT EXPECTING THE VERY HIGH BASED WESTERN NEB SPRINKLES
CURRENTLY NOTED ON RADAR TO HAVE ANY IMPACT LOCALLY. THE MID-
UPPER LEVEL PICTURE REMAINS FAIRLY STEADY-STATE UNDER A BAND OF
MODESTLY STRONG NORTHWESTERLY FLOW...AS A RATHER SUBTLE LOW-
AMPLITUDE DISTURBANCE GRADUALLY APPROACHES THE LOCAL AREA FROM THE
NORTHWEST. AT THE SURFACE...THE COMBINATION OF A TIGHTENING
PRESSURE GRADIENT BETWEEN THE DEPARTING RIDGE AND MODEST HIGH
PLAINS PRESSURE FALLS TO THE WEST...ALONG WITH MIXING UP INTO A
WEAK-MODEST LOW LEVEL JET WILL PROMOTE INCREASING SOUTHERLY
BREEZES...ESPECIALLY DURING THE MID-MORNING TO MID-AFTERNOON
HOURS...WITH SUSTAINED SPEEDS GENERALLY 10-15 MPH AND GUSTS TO
AROUND 20 MPH ESPECIALLY WITHIN THE WESTERN 1/2 OF THE CWA. NOT TO
KEEP BEATING THE DRUM ON THIS ISSUE...BUT THE UNCERTAINTY IN THE
PRESENCE OR LACK THEREOF OF THE POTENTIAL INVADING STRATUS DECK
CERTAINLY RAISES SOME CONSIDERABLE QUESTIONS ON SKY COVER AND
RESULTANT TEMPS...WITH LIKELY AROUND A 5-DEGREE TEMP BUST
POTENTIAL ON THE LINE. BASED ON THE LATEST 06Z NAM 850 MILLIBAR
RELATIVE HUMIDITY PROGS...AT LEAST A LIMITED COVERAGE OF PARTLY-
MOSTLY CLOUDY SKIES SHOULD SLOWLY OVERTAKE THE CWA FROM SOUTHWEST-
NORTHEAST TODAY...WHILE THE LATEST HRRR LOW CLOUD COVER PRODUCT
SUGGESTS STRATUS COULD BE A MORE MINIMAL ISSUE AS ALTHOUGH IT
STILL BRINGS IT INTO MAINLY THE SOUTHWEST 1/2 TO 1/3 OF THE CWA IT
DIMINISHES IT AREA WITH TIME AND EVEN MIXES IT OUT ALMOST
COMPLETELY IN THE AFTERNOON. NOT SURPRISINGLY...THE OFFICIAL SKY
COVER FORECAST IS A HEDGE...SUGGESTING THAT THE DAY AS A WHOLE
STARTS OUT MOSTLY SUNNY IN MOST AREAS BUT THEN BECOMES AT LEAST
PARTLY CLOUDY WITH AT LEAST A BRIEF FEW HOURS OF MOSTLY CLOUDY
PASSING THROUGH. EVEN WITHOUT LOWER STRATUS...A FEW DECENT PATCHES
OF MID LEVEL CLOUDS COULD ALSO WORK OVERHEAD FROM THE NORTHWEST.
STAY TUNED FOR PLENTY OF SKY COVER FINE TUNING BY DAY SHIFT. HIGH
TEMP-WISE...FOLLOWED A BLEND OF VARIOUS MODELS/GUIDANCE TO YIELD
AROUND A 2-3 DEGREE RISE FROM PREV FORECAST...WHICH PUTS MOST OF
THE CWA IN THE 69-73 RANGE BUT WITH SLIGHTLY WARMER GENERALLY
74-77 IN FAR SOUTHWEST ZONES. BY THIS AFTERNOON SURFACE DEWPOINTS
SHOULD HAVE RISEN BACK UP SOMEWHERE IN THE 50S...HIGHEST
SOUTHWEST.
THIS EVENING-TONIGHT...THE MID-UPPER LEVEL STORY INVOLVES
CONTINUED FAIRLY STEADY-STATE NORTHWESTERLY FLOW ALOFT AS A VERY
LOW-AMPLITUDE/CHANNELED SHORTWAVE TROUGH SLIDES CLIPS THROUGH
MAINLY JUST TO THE NORTHEAST OF THE CWA ALONG A TRACK FROM THE
DAKOTAS THROUGH IA INTO NORTHERN MO. AS THIS WAVE PASSES BY...IT
WILL INDUCE A MODEST INCREASE IN THE LOW LEVEL JET AND ASSOCIATED
THETA-E ADVECTION/ISENTROPIC LIFT THAT WILL GRADUALLY VEER FROM
SOUTHWESTERLY TO MORE WESTERLY...ALTHOUGH THE MAIN NOSE OF THIS
FORCING LOOKS TO AIM EASTERN KS AND NOT SO MUCH LOCALLY. AS A
RESULT...THE MAJORITY OF BOTH DETERMINISTIC AND HIGHER RES-
SIMULATED REFLECTIVITY MODELS SUCH AS THE 4KM WRF-NMM FOCUS
OVERNIGHT CONVECTION AT LEAST A FEW COUNTIES EAST-SOUTHEAST OF THE
CWA. HOWEVER...GIVEN THAT THE PREVIOUS FORECAST ALREADY WAS
CARRYING A SLIGHT SHOWER/STORM CHANCE IN SOUTHEAST ZONES AND THAT
THE GFS IN PARTICULAR STILL TRIES TO INITIATE STORMS IN THIS
AREA...HAVE HELD ONTO THIS SLIGHT CHANCE MAINLY SOUTHEAST OF A
GENEVA-PLAINVILLE LINE POST-MIDNIGHT...BUT REMOVED ANY PRECIP
CHANCES EARLIER IN THE EVENING GIVEN THAT LIFT DOES NOT APPEAR
SUFFICIENT TO GENERATE CONVECTION BEFORE THEN. SHOULD ANY STORMS
BE REALIZED...CERTAINLY A FEW STRONG UPDRAFTS CAPABLE OF
PRODUCING AT LEAST NEAR-SEVERE HAIL CANNOT BE RULED OUT GIVEN THE
06Z NAM SUGGESTION OF UP TO AROUND 1500 J/KG MUCAPE IN THE
850-700MB LAYER AND AROUND 40KT OF DEEP LAYER SHEAR. AS A
RESULT...WILL CONTINUE TO MENTION NICKEL SIZE HAIL POTENTIAL IN
THE LOCAL HAZARDOUS WEATHER OUTLOOK IN SOUTHEAST AREAS...DESPITE
THE FACT THAT THE LATEST SPC DAY 1 OUTLOOK REMOVED THE 5 PERCENT
SEVERE PROBABILITY CONTOUR FROM THE CWA THAT HAD BEEN PRESENT ON
THE FORMER DAY 2 OUTLOOK. AGAIN THOUGH...NO MATTER WHAT THE
MAJORITY OF THE CWA SHOULD GET THROUGH THE NIGHT DRY. TURNING TO
THE SURFACE SITUATION...GENERALLY 5-8 MPH SOUTHEASTERLY BREEZES
THIS EVENING SHOULD BECOME EVEN LIGHTER AND MORE EASTERLY AFTER
MIDNIGHT. ASSUMING THAT OVERNIGHT SKIES AVERAGE NO WORSE THAN
PARTLY CLOUDY IN THE WAKE OF POTENTIAL EASTWARD-EXITING STRATUS
FROM THE DAYTIME HOURS...THE STAGE COULD BE SET FOR SOME
POTENTIALLY DECENT AT-LEAST-LIGHT FOG FORMATION...AND MAYBE SOME
MORE IMPACTFUL FOG ESPECIALLY WITHIN THE WESTERN 1/2 OF THE CWA
PER THE LATEST SREF VISIBILITY PROBABILITY PRODUCTS. EXPERIENCE
HAS SHOWN THAT FOG IS ALMOST NEVER A "SURE THING" UNTIL IT
ACTUALLY FORMS...BUT FELT IT WOULD BE PRUDENT TO INTRODUCE A
GENERIC PATCHY FOG WORDING TO ALL AREAS LATE TONIGHT...AND A
SOMEWHAT HARDER-HITTING AREAS OF FOG MENTION TO WESTERN COUNTIES.
ITS JUST TOO SOON TO SAY WHETHER OR NOT FOG COULD CAUSE IMPACTFUL
ISSUES FOR THE WED MORNING COMMUTE. AS FOR LOW TEMPS...MADE VERY
LITTLE CHANGE HERE...AS THE INCREASED LOW LEVEL MOISTURE SHOULD
HELP HOLD UP LOWS GENERALLY 5-10 DEGREES HIGHER THAN THIS
MORNING...AND AM CALLING FOR A RANGE FROM NEAR-50 FAR
NORTH...LOW-MID 50S CENTRAL AND NEAR 60 FAR SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 435 AM CDT TUE SEP 16 2014
THE WARMEST DAY OF THE NEXT 7 DAYS WILL BE FRIDAY WITH HIGHS IN THE
MID 80S AHEAD OF A COLD FRONT. THE BEST CHANCE OF
SHOWERS/THUNDERSTORMS CURRENTLY APPEARS TO BE ASSOCIATED WITH THAT
COLD FRONTAL PASSAGE FRIDAY NIGHT INTO THE FIRST HALF OF SATURDAY.
THE COOLEST DAY OF THE WEEK WILL ACTUALLY BE TODAY WITH HIGHS OF 70
TO 75. SO OVERALL THIS WILL BE A RATHER NICE WEEK WITH HIGHS NEAR
NORMAL FOR THIS TIME OF YEAR...WHICH IS GENERALLY IN THE UPPER 70S.
WEDNESDAY/WEDNESDAY NIGHT...AN UPPER LEVEL RIDGE WILL BE CENTERED
OVER THE ROCKIES WITH NORTHWESTERLY FLOW ALOFT ACROSS THE CENTRAL
PLAINS. THERE WILL BE DECENT INSTABILITY AND WIND SHEAR ACROSS OUR
FORECAST AREA...BUT FORCING IS RATHER WEAK. THERE MAY BE A WEAK
UPPER WAVE RIDING DOWN THE EAST SIDE OF THE RIDGE OR PERHAPS
SLIGHTLY BETTER LIFT AFTER DARK WEDNESDAY NIGHT AS A WEAK LOW LEVEL
JET LIFTS OVER THE EAST SOUTHEAST SFC FLOW. HOWEVER...THE BETTER LOW
LEVEL JET SET UP APPEARS TO BE TO OUR SOUTHEAST OVER NORTHEAST
KANSAS. SO OVERALL...FORCING JUST SEEMS RATHER QUESTIONABLE AND WILL
ONLY CARRY LOWER END POPS BEGINNING WEDNESDAY NIGHT WITH THE REALITY
BEING MOST LOCATIONS WILL MORE LIKELY THAN NOT BE DRY.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES WILL DECREASE. A FEW
FORECAST MODELS ARE STILL HINTING AT LOW END CHANCES OF
PRECIPITATION ACROSS OUR FORECAST AREA...BUT AM NOT VERY OPTIMISTIC
THAT THERE WILL BE MUCH OUT THERE GIVEN THE RIDGE MOVING IN.
THEREFORE...DECREASED OUR POPS AND DOWNGRADED SHOWER AND
THUNDERSTORM CHANCES TO JUST ISOLATED SPRINKLES.
FRIDAY THROUGH SATURDAY...AS MENTIONED ABOVE...FRIDAY WILL BE THE
WARMEST DAY OF THE NEXT 7 DAYS AS GUSTY SOUTHERLY WINDS PUMP WARMER
AIR INTO THE REGION AHEAD OF AN APPROACHING COLD FRONT. AN
INTERESTING WRINKLE IN THIS FORECAST IS WHAT WILL HAPPEN WITH THE
REMNANTS OF HURRICANE ODILE...WHICH IS CURRENTLY LOCATED OVER THE
BAJA PENINSULA OF MEXICO. THE 00Z GFS AND 00Z ECMWF BOTH BRING
REMNANT MOISTURE FROM THIS DECAYING TROPICAL SYSTEM NORTH NORTHEAST
INTO THE CENTRAL PLAINS...WHERE IT WILL WORK INTO AN UPPER LEVEL
STORM SYSTEM THAT IS TRACKING EAST THROUGH THE CENTRAL PLAINS. THERE
ARE STILL PLENTY OF QUESTIONS WITH REGARD TO THE TIMING OF WHEN THE
TROPICAL MOISTURE PLUME WILL ARRIVE AND HOW THAT WILL INTERACT WITH
OUR MID LATITUDE UPPER TROUGH. THE MOST LIKELY TIME FOR
PRECIPITATION WILL BE FROM FRIDAY NIGHT THROUGH SATURDAY
MORNING...WITH THE SYSTEM EXITING TO OUR EAST BY SATURDAY AFTERNOON.
TEMPERATURES WILL BE SLIGHTLY COOLER SATURDAY BEHIND THE COOL
FRONT...BUT NOTHING MAJOR WITH HIGHS ONLY AROUND 5F COOLER.
SUNDAY THROUGH MONDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH DRY WEATHER LIKELY FOR OUR FORECAST AREA. HIGH
TEMPERATURES WILL BE NEAR NORMAL IN THE 70S.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY)
ISSUED AT 101 AM CDT TUE SEP 16 2014
ALTHOUGH CONFIDENCE IS REASONABLY HIGH IN BOTH VFR CEILING AND
VISIBILITY PREVAILING THROUGH THE PERIOD...ALONG WITH VERY LITTLE
IF ANY RISK OF PRECIPITATION...THERE IS SOME MAJOR UNCERTAINTY
REGARDING WHETHER OR NOT A POTENTIALLY EXPANSIVE CEILING RATHER
CLOSE TO THE VFR-MVFR HEIGHT BREAKPOINT COULD MOVE IN FOR SEVERAL
HOURS MAINLY DURING THE LATTER HALF OF THE PERIOD THIS
AFTERNOON/EVENING. PRESENTLY...A DECK OF CLOUDS AT THIS LEVEL ARE
LOCATED NEARLY 200 MILES SOUTHWEST OF THE TERMINALS...AND THE MAIN
QUESTION IS WHETHER THIS CLOUD DECK WILL CONTINUE TO GRADUALLY
EXPAND NORTHEAST WITH TIME. TAKING A BEST STAB AT TIMING...HAVE
DELAYED THE ONSET AND DEPARTURE OF POTENTIAL LOW-VFR CEILING A
FEW HOURS VERSUS PREVIOUS FORECAST...BUT AGAIN UNCERTAINTY IS
HIGH. VISIBILITY WISE...THERE APPEARS TO BE SOME VERY PATCHY
LIGHT FOG COMING AND GOING EARLY THIS MORNING...BUT BELIEVE ANY
SUB-VFR OBSERVATIONS SHOULD BE QUITE FLEETING AND THUS WILL
MAINTAIN PREVAILING VFR. AS FOR SURFACE WINDS...VERY LIGHT BREEZES
THIS MORNING WILL STEADILY INCREASE AFTER SUNRISE AS MIXING
DEEPENS...WITH MUCH OF THE DAY FEATURING A SOUTHERLY SUSTAINED
BREEZE OF 10-15KT WITH SLIGHTLY HIGHER GUSTS...BEFORE WINDS SUBSIDE
A BIT FROM A PREVAILING SOUTH-SOUTHEAST DIRECTION IN THE EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
331 AM EDT TUE SEP 16 2014
.SYNOPSIS...A COLD FRONT APPROACHING THE REGION FROM THE WEST
TONIGHT WILL TRACK SLOWLY SOUTHWARD THROUGH THE CAROLINAS TODAY
AND TONIGHT. THE FRONT WILL GRADUALLY MOVE OFFSHORE THE
SOUTHEAST COAST ON WEDNESDAY AND THURSDAY AS HIGH PRESSURE
STRENGTHENS OVER THE GREAT LAKES AND EXTENDS SOUTHWARD THROUGH THE
MID ATLANTIC.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM TUESDAY...
TODAY...WEAK MID-UPPER LEVEL DISTURBANCE EXITING THE REGION EARLY
THIS MORNING. PATCHES OF LIGHT RAIN OR SHOWERS SHOULD CONTINUE TO
DECREASE IN COVERAGE/INTENSITY THROUGH DAYBREAK. ABUNDANT LOW LEVEL
MOISTURE SHOULD RESULT IN THE FORMATION OF A LOW CLOUD DECK BY
DAYBREAK. WEAK SUBSIDENCE IN THE WAKE OF THIS EXITING FEATURE
COMBINED WITH A DOWNSLOPE COMPONENT TO THE 925-850MB WIND AFTER 12Z
SHOULD AID TO DIMINISH/DISSIPATE THE WIDESPREAD LOW CLOUDS BY LATE
MORNING-MID DAY.
HEATING OF THE ATMOSPHERE IN COMBINATION WITH RESIDUAL MOISTURE AND
THE APPROACH OF ANOTHER MID-UPPER LEVEL DISTURBANCE SHOULD TRIGGER
SCATTERED SHOWERS-ISOLATED THUNDERSTORMS. LATEST ROUND OF WRF MODEL
RADAR PRESENTATIONS ALONG WITH THE HRRR FAVOR INITIAL DEVELOPMENT IN
THE WESTERN PIEDMONT AROUND MID AFTERNOON. THE 00Z GFS (AND MORE SO
THE 00Z NAM) INDICATE SLIGHT INSTABILITY OVER THE WESTERN PIEDMONT
ALONG WITH SOME BULK SHEAR OF SUFFICIENT MAGNITUDE (25-30KTS) TO
ALLOW FOR SOME LOOSELY ORGANIZED CONVECTION. SOME WRF MODELS SUGGEST
BROKEN BAND OF CONVECTION MAKING IT INTO THE TRIANGLE REGION BEFORE
WEAKENING/DISSIPATING. CONSIDERING THE LACK OF RADAR ECHOES UPSTREAM
ASSOCIATED WITH THE NEXT DISTURBANCE...NOT READY TO INCREASE ANY
MORE THAN CURRENT 20-40 PERCENT. HOWEVER...HAVE SHIFTED POP EMPHASIS
MORE TO THE WESTERN PIEDMONT RATHER THAN THE SOUTHERN COASTAL PLAIN
DUE TO BETTER PROXIMITY OF UPPER LEVEL SUPPORT.
MOS GUIDANCE CONTINUES TO ADVERTISE MAX TEMPS SOLIDLY IN THE MID
80S. THESE TEMPS ACHIEVABLE IF LOW CLOUDS DEPART/DISSIPATE PRIOR TO
15Z AND SCATTERED CONVECTION HOLDS OFF UNTIL MID AFTERNOON. FAVOR
MAX TEMPS SLIGHTLY COOLER THAN MOS (LOWER 80S NW TO MID 80S
ELSEWHERE).
TONIGHT...SCATTERED CONVECTION WILL GRADUALLY WEAKEN WITH LOSS OF
HEATING AND EXITING OF MID LEVEL DISTURBANCE. STILL...COULD SEE A
FEW SHOWERS PERSIST PAST MIDNIGHT TOT EH EAST-SOUTH OF RDU.
CLOUDINESS AND LACK OF APPRECIABLE LOW LEVEL CAA SUGGEST MIN TEMPS A
FEW DEGREES WARMER THAN EARLIER THINKING. MIN TEMPS LOW-MID 60S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 330 AM TUESDAY...
WEDNESDAY...ABUNDANT LOW LEVEL MOISTURE TRAPPED BENEATH A LOW LEVEL
INVERSION SHOULD RESULT IN EXTENSIVE CLOUDINESS OVER MOST OF THE
REGION WEDNESDAY MORNING...AND POTENTIALLY LINGERING INTO THE
AFTERNOON ACROSS THE PIEDMONT. (THIS MAY BE CLASSIFIED AS A HYBRID
OR INSITU DAMMING EVENT THOUGH PARENT HIGH RELATIVELY WEAK AND QUITE
TRANSITORY). IF EXTENSIVE CLOUDS DO LINGER PAST MID DAY ACROSS THE
PIEDMONT...THIS MAY CREATE A DIFFERENTIAL HEATING BOUNDARY BETWEEN
THE PIEDMONT AND THE SANDHILLS/SOUTHERN COASTAL PLAIN. THE APPROACH
OF YET ANOTHER DISTURBANCE IN THE WEST-NW FLOW ALOFT INTERACTING
WITH THIS FEATURE MAY TRIGGER MORE SCATTERED CONVECTION...MAINLY
OVER THE SE THIRD OF OUR FORECAST AREA. THE LOW LEVEL STABLE AIR
MASS SUGGEST MAINLY PATCHY STRATIFORM RAIN OVER THE NORTHERN
PIEDMONT (OR ELEVATED SHOWERS. SINCE LEANING TOWARD MORE CLOUDINESS
ACROSS THE PIEDMONT...HAVE LOWERED MAX TEMPS A COUPLE OF DEGREES BUT
RAISED MAX TEMPS TO NEAR/ABOVE 80 OVER THE SE COUNTIES.
CONTINUED CYCLONIC FLOW ALOFT WILL MAINTAIN CLOUDINESS WEDNESDAY
NIGHT ALONG WITH A SMALL THREAT FOR SHOWERS...MAINLY EAST OF HIGHWAY
1. MIN TEMPS SEVERAL DEGREES COMPARED TO THE PREVIOUS NIGHT. MIN
TEMPS UPPER 50S NW TO LOWER 60S SE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...
THE MEDIUM RANGE WILL FEATURE A LONGWAVE TROUGH THAT WILL MOVE
OFFSHORE THE EAST COAST THU AND CONSEQUENTLY YIELD TO RISING HEIGHTS
ALOFT AS A FLAT MID LEVEL RIDGE RIDGE BRIEFLY BUILDS EAST FROM THE
SOUTHERN PLAINS AND LOWER MS VALLEY FRI-SAT. THE RE-ESTABLISHMENT OF
A WESTERN NOAM RIDGE WILL THEN RESULT IN DOWNSTREAM TROUGH
AMPLIFICATION FROM SOUTH-CENTRAL CANADA TO THE EAST-CENTRAL US SUN-
MON...THE LEAD SHORTWAVE TROUGH OF WHICH WILL INCLUDE THE REMNANTS
OF TROPICAL STORM ODILE.
MEANWHILE AT THE SFC...A CANADIAN-SOURCE SFC HIGH (AROUND 1030 MB)
WILL BUILD FROM CENTRAL CANADA TO THE CANADIAN MARITIMES AND RIDGE
SOUTH/SOUTHWESTWARD IN DAMMING ORIENTATION EAST OF THE APPALACHIANS
THU THROUGH THE WEEKEND...FOLLOWED BY A COLD FRONTAL PASSAGE -
DRIVEN BY THE AFOREMENTIONED RE-AMPLIFICATION OF THE LONGWAVE TROUGH
INTO THE EAST-CENTRAL US - ON MON.
THE RESULT WILL BE A RELATIVELY PROLONGED PERIOD OF EAST TO
NORTHEAST LOW LEVEL FLOW AND ASSOCIATED BELOW NORMAL TEMPERATURES...
TEMPERED FURTHER BY PERIODS OF BKN MULTI-LAYERED CLOUD
COVER...THROUGH EARLY THIS WEEKEND. THE RELATIVE GREATEST CLOUD
COVERAGE WILL LINGER THU (FROM WED NIGHT)...WHEN A LINGERING CHANCE
OF SHOWERS WILL ALSO REMAIN...MAINLY OVER THE COASTAL WHERE A
DEPARTING H85 WAVE/TROUGH WILL AUGMENT WEAK FORCING ALOFT ATTENDING
A PAIR OF SHORTWAVE TROUGHS FORECAST TO CROSS THE CAROLINAS AND
MIDDLE ATLANTIC THROUGH MID-LATE THU AFTERNOON. UNDER ASSOCIATED
VARIABLY CLOUDY SKY COVER...WITH RELATIVE GREATEST COVERAGE
EAST...TEMPERATURES SHOULD FALL ABOUT A CATEGORY OR SO SHY OF WHAT
FULL SUN THICKNESSES OF AROUND 1385 METERS WOULD OTHERWISE SUPPORT.
COOL AGAIN OVERNIGHT WITH DEEP LAYER DRYING/FALLING PRECIPITABLE
WATER VALUES TO AROUND AN INCH...AS THE AFOREMENTIONED MID LEVEL
RIDGE EXPANDS EASTWARD AND CAUSES - LOWS MIDDLE 50S TO AROUND 60.
OTHERWISE...THE INCREASING INFLUENCE OF THE RIDGING AT THE SFC AND
ALOFT SHOULD PROMOTE DRY CONDITIONS FRI-SUN...THOUGH WITH
TEMPERATURES MODERATING ONLY SLOWLY THROUGH THE 70S...TO AROUND 80
DEGREES BY SUN. THE PASSAGE OF THE SFC COLD FRONT EARLY NEXT WEEK
SHOULD THEN SUPPORT A CHANCE OF SHOWERS IN CENTRAL NC ON MON. ONCE
THE INHERENT D7 TIMING DIFFERENCES ARE IRONED OUT...A SLIGHT CHANCE
OF THUNDER MAY BE INTRODUCED WITH LATER FORECASTS IF IT APPEARS
FAVORABLE DIURNAL TIMING OF THE FRONTAL PASSAGE WILL OCCUR.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 140 AM TUESDAY...
AVIATION CONDITIONS AT 0530Z VARY FROM VFR TO MVFR ACROSS CENTRAL
NC. A DETERIORATING TEND ANTICIPATED THROUGH 10Z WITH IFR/LIFR
CEILINGS HIGHLY PROBABLE AND WIDESPREAD MVFR VISIBILITY DUE TO FOG.
THE ADVERSE AVIATION CONDITIONS SHOULD LINGER THROUGH 14Z WITH AN
IMPROVEMENT TO VFR CONDITIONS MOST LOCATIONS BY 16Z. SURFACE WINDS
WILL BE LIGHT AND VARIABLE...BECOMING NORTH NORTHWEST AT 5KTS OR
LESS AFTER 14Z AS A WEAK COLD FRONT DRIFTS ACROSS THE REGION.
PATCHES OF LIGHT RAIN WILL OCCUR AHEAD OF THIS FEATURE. LATER THIS
AFTERNOON...ISOLATED SHOWERS AND POSSIBLY A THUNDERSTORM MAY
OCCUR...MAINLY IN THE VICINITY OF KFAY.
VFR CONDITIONS ANTICIPATED TONIGHT THROUGH WEDNESDAY WITH A BRIEF
PERIOD OF MVFR CEILING/VISIBILITY POSSIBLE EARLY WEDNESDAY MORNING.
THE PERIOD THURSDAY THROUGH SATURDAY APPEARS TRANQUIL WITH MAINLY
VFR CONDITIONS. A BRIEF INSTANCE OF MVFR CEILING OR VISIBILITY MAY
OCCUR EACH MORNING...MAINLY IN THE VICINITY OF KRWI AND KFAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS/VINCENT
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...MWS
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
140 AM EDT TUE SEP 16 2014
.SYNOPSIS...A COLD FRONT APPROACHING THE REGION FROM THE WEST
TONIGHT WILL TRACK SLOWLY SOUTHWARD THROUGH THE CAROLINAS TODAY
AND TONIGHT. THE FRONT WILL GRADUALLY MOVE OFFSHORE THE
SOUTHEAST COAST ON WEDNESDAY AND THURSDAY AS HIGH PRESSURE
STRENGTHENS OVER THE GREAT LAKES AND EXTENDS SOUTHWARD THROUGH THE
MID ATLANTIC.
&&
.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM MONDAY...
OVERVIEW: CENTRAL NC IS SITUATED ON THE NORTHEAST PERIPHERY OF A
GULF COAST RIDGE...AT THE SOUTHERN FRINGE OF THE WESTERLIES IN BROAD
CYCLONIC FLOW ALOFT. 02Z WV IMAGERY AND RAP DATA INDICATED SMALL
AMPLITUDE SHORTWAVE ENERGY OVER EASTERN TN AND FAR SOUTHWESTERN NC.
PRECIPITATION: COMPACT DPVA IN THE PRESENCE OF LOW-LEVEL MOISTENING/
WARM ADVECTION AND RESULTING DESTABILIZATION ALLOWED CONVECTION TO
BLOSSOM OVER THE MOUNTAINS/FOOTHILLS BETWEEN 21-00Z. THIS ACTIVITY
HAS PERSISTED AND PROGRESSED EASTWARD TO THE YADKIN RIVER BY 03Z AND
APPEARS TO BE EITHER 1) ELEVATED OR 2) HIGH-BASED WITH CONVECTIVE
CEILINGS AT 7-10 KFT AND OBSERVATION SITES REPORTING SPRINKLES/LIGHT
RAIN WITH 7-10SM VISBYS AS PRECIP FALLS THROUGH A DRY MID-LEVEL
AIRMASS (AS SEEN ON THE 00Z GSO SOUNDING). THIS ACTIVITY WILL TRACK
EAST TOWARD THE HWY 1 CORRIDOR THROUGH 06Z IN ASSOC/W THE
APPROACHING SHORTWAVE...THOUGH IT WILL ENCOUNTER AN INCREASINGLY
UNFAVORABLE THERMODYNAMIC ENVIRONMENT AND THUS APPEARS LIKELY TO
WEAKEN WITH EASTWARD PROGRESSION. WILL INDICATE A SLIGHT TO LOW
CHANCE OF SHOWERS/SPRINKLES THROUGH 06Z WEST OF I-95...WITH THE BEST
CHANCE IN THE WESTERN PIEDMONT. -VINCENT
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...
FOR TUE/TUE NIGHT: THE WEAK SURFACE TROUGH WILL BE IN PLACE OVER ERN
NC TUE MORNING... AND WILL EXTEND A SLIGHT CHANCE OF SHOWERS IN THE
SOUTHEAST INTO TUE TO REFLECT THE TROUGH`S PRESENCE AND THE
DEPARTING MID LEVEL WAVE. WITH SUBSEQUENT NORTHWESTERLY DOWNSLOPE
925-850 MB FLOW... WE SHOULD THEN BE FAIRLY DRY FOR SEVERAL HOURS...
UNTIL THE NEXT MID LEVEL VORTICITY MAX AND ACCOMPANYING STRONGER
SURFACE COLD FRONT APPROACH FROM THE NW BY EARLY-MID AFTERNOON.
SURFACE-925 MB LOW PRESSURE ALONG THIS FRONT WILL APPROACH FROM THE
NW AND BECOME BETTER DEFINED AS IT CROSSES THE MOUNTAINS INTO THE
PIEDMONT OF NC DURING THE AFTERNOON. MODELS SHOW A POCKET OF 6+ C/KM
MID LEVEL LAPSE RATES CROSSING SRN NC LATE TUE ALONG WITH NEGATIVE
LI VALUES. MUCAPE SHOULD PEAK AT JUST 750-1500 J/KG FOCUSED ON THE
SOUTHEAST... AND DEEP LAYER SHEAR IS MARGINAL AT ABOUT 20-25 KTS...
BUT THESE NUMBERS COMBINED WITH LOW LEVEL MASS CONVERGENCE SHOULD
STILL SUPPORT SCATTERED SHOWERS AND ISOLATED STORMS LATE TUE
AFTERNOON THROUGH TUE NIGHT. CONFIDENCE IN THE COVERAGE AND
PLACEMENT IS NOT GREAT HOWEVER... AS THERE IS LITTLE AGREEMENT IN
QPF AND POPS AMONG THE NAM/GFS/ECMWF. BUT GENERALLY EXPECT THE BEST
COVERAGE TO BE IN THE SOUTHEAST CWA... WHERE MOISTURE TRANSPORT AND
INSTABILITY WILL BE BEST... FROM LATE AFTERNOON THROUGH THE
EVENING... TAPERING DOWN TO ISOLATED SHOWERS OVERNIGHT. THICKNESSES
ADJUSTED FOR CLOUDS AND POSSIBLE SHOWERS LATE SUPPORT HIGHS FROM 82
TO 86. LOWS 60-65 TUE NIGHT AS COOLER AND DRIER AIR STARTS TO FILTER
IN POST-FRONT FROM THE NNW. -GIH
WEDNESDAY AND WEDNESDAY NIGHT...WESTERLY FLOW ALOFT WILL INDUCE
PROGRESSIVE TOP DOWN DRYING THROUGH WEDNESDAY NIGHT...LESSENING THE
DEPTH OF MOISTURE...WHILE NORTHEAST LOW LEVEL FLOW MAINTAINS
MOISTURE THROUGH ABOUT 5KFT THROUGH THURSDAY MORNING. A SHORT WAVE
WILL BE MOVING ACROSS THE SOUTHERN PERIPHERY OF THE AREA ON
WEDNESDAY...ACCOMPANIED BY AN H85 WAVE THAT WILL ENHANCE LIFT VIA
CONVERGENCE AND WEAK ISENTROPIC LIFT AT THE TOP OF THE MOISTURE
COLUMN. HENCE WILL MAINTAIN A CHANCE POP FOR SHOWERS ACROSS THE
SOUTH AND A SLIGHT CHANCE ACROSS THE NORTH THROUGH WEDNESDAY...
DIMINISHING TO A LINGERING SLIGHT CHANCE IN THE EAST INTO THURSDAY.
COOL AIR ADVECTION WILL COMMENCE LATE DAY AS THE SHORT WAVE PASSES
AND WITH THE DAMPNESS AND CHANCE OF SHOWERS...HIGHS WEDNESDAY WILL
RANGE FROM 75 TO 80...WITH SOME LOWER 70S POSSIBLE ACROSS THE
NORTHEAST WHERE COOL AIR WILL ARRIVE A LITTLE SOONER. LOWS WEDNESDAY
NIGHT WILL BE MAINLY IN THE UPPER 50S. -MLM
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...
A LONG WAVE TROF SETS UP ACROSS THE EASTERN CONUS BY LATE WEEK...
CONCURRENT WITH STRONG HIGH PRESSURE BUILDING INTO EASTERN CANADA
AND DOWN THE EAST COAST ON FRIDAY WITH THE RESULTING DAMMING
SCENARIO LINGERING THROUGH THE WEEKEND. LOW AMPLITUDE MID LEVEL
RIDGING SHOULD INHIBIT PRECIP CHANCES THROUGH THE WEEKEND...WHILE
THE PROLONGED EAST TO NORTHEAST LOW LEVEL FLOW OFF THE ATLANTIC WILL
SUPPRESSES HIGH TEMPS INTO THE LOW AND MID 70S THROUGH SATURDAY.
A STRONG TROF MOVING ACROSS THE MIDWEST WILL NUDGE THE SURFACE HIGH
FURTHER OFFSHORE. THE WEAKENED FLOW WILL ALLOW THE AIRMASS TO
MODERATE ON SUNDAY...WITH HIGHS MOSTLY IN THE UPPER 70S. FLOW VEERS
TO SOUTHWEST BY MONDAY AHEAD OF THE UPPER TROF AND SURFACE
FRONT...WITH INCREASING MOISTURE IN THE RESULTING RETURN FLOW AND A
CHANCE OF SHOWERS BY LATE DAY MONDAY. HIGHS MONDAY WILL BE WITHIN A
DEGREE OR TWO OF 80. MORNING LOWS THROUGH THE PERIOD WILL BE MOSTLY
FROM 55 TO 60 DEGREES. -MLM
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 140 AM TUESDAY...
AVIATION CONDITIONS AT 0530Z VARY FROM VFR TO MVFR ACROSS CENTRAL
NC. A DETERIORATING TEND ANTICIPATED THROUGH 10Z WITH IFR/LIFR
CEILINGS HIGHLY PROBABLE AND WIDESPREAD MVFR VISIBILITY DUE TO FOG.
THE ADVERSE AVIATION CONDITIONS SHOULD LINGER THROUGH 14Z WITH AN
IMPROVEMENT TO VFR CONDITIONS MOST LOCATIONS BY 16Z. SURFACE WINDS
WILL BE LIGHT AND VARIABLE...BECOMING NORTH NORTHWEST AT 5KTS OR
LESS AFTER 14Z AS A WEAK COLD FRONT DRIFTS ACROSS THE REGION.
PATCHES OF LIGHT RAIN WILL OCCUR AHEAD OF THIS FEATURE. LATER THIS
AFTERNOON...ISOLATED SHOWERS AND POSSIBLY A THUNDERSTORM MAY
OCCUR...MAINLY IN THE VICINITY OF KFAY.
VFR CONDITIONS ANTICIPATED TONIGHT THROUGH WEDNESDAY WITH A BRIEF
PERIOD OF MVFR CEILING/VISIBILITY POSSIBLE EARLY WEDNESDAY MORNING.
THE PERIOD THURSDAY THROUGH SATURDAY APPEARS TRANQUIL WITH MAINLY
VFR CONDITIONS. A BRIEF INSTANCE OF MVFR CEILING OR VISIBILITY MAY
OCCUR EACH MORNING...MAINLY IN THE VICINITY OF KRWI AND KFAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS/VINCENT
NEAR TERM...VINCENT
SHORT TERM...HARTFIELD/MLM
LONG TERM...MLM
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1146 PM CDT MON SEP 15 2014
.AVIATION...
A COLD FRONT CONTINUES TO SLOWLY MOVE SOUTHWARD OVERNIGHT. WINDS
HAVE SHIFTED TO THE NORTH FROM KGAG/KWWR TO KPNC. EXPECT WINDS TO
SHIFT TO THE NORTH AT ALL TERMINALS BY 12Z TUES. WHAT REMAINS
UNCLEAR IS THE POTENTIAL FOR LOW STRATUS TO DEVELOP IN THE POST
FRONTAL AIR. SO FAR...LOW CLOUDS HAVE BEEN VERY SLOW TO BUILD INTO
NORTHERN/WESTERN OKLAHOMA IN THE WAKE OF THE FRONT.
HOWEVER...GUIDANCE AND HIGH RES MODELS CONTINUE TO SUGGEST
MVFR/IFR CIGS WILL BECOME MORE PREVALENT FROM 09Z TO 14Z AT NEARLY
ALL TERMINALS. WHILE A SPOTTY SHOWER OR TWO MAY AFFECT TAF SITES
FROM I-40 SOUTHWARD...GREATER CHANCES FOR SHRA/TSRA WILL REMAIN
OVER WESTERN NORTH TEXAS...AND WILL MAINTAIN PROB30 GROUP OF ISOLD
TSRA. WINDS WILL GRADUALLY SHIFT BACK TO THE SOUTH BY 18Z...WITH
LOW CIGS GRADUALLY CLEARING.
&&
.PREV DISCUSSION... /ISSUED 851 PM CDT MON SEP 15 2014/
UPDATE...
HAVE MADE SOME MINOR CHANGES TO THE GRIDS FOR TONIGHT. BASED ON
LATEST COUPLE OF RUNS OF THE HRRR WILL KEEP LOWER END CHANCE POPS
ACROSS PORTIONS OF CENTRAL INTO SOUTHEAST OKLAHOMA THIS EVENING
AND THEN A BIT HIGHER ACROSS SOUTHERN OK INTO NORTH TEXAS LATE
TONIGHT AS SFC FRONT WORKS SOUTH TOWARD THE RED RIVER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 64 82 66 87 / 30 20 10 20
HOBART OK 65 85 67 89 / 20 20 10 10
WICHITA FALLS TX 68 86 69 89 / 30 40 10 20
GAGE OK 59 83 64 90 / 20 10 10 10
PONCA CITY OK 61 79 63 86 / 20 10 20 30
DURANT OK 68 87 69 88 / 30 30 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/84
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1131 PM CDT MON SEP 15 2014
.AVIATION...
/06Z TAFS/
Mainly VFR conditions expected at the terminals the next 24 hours.
Abundant mid and upper level clouds will remain over the area
tonight into Tuesday. Widespread stratus appears unlikely late
tonight into Tuesday morning due to extensive mid and high
cloudiness but cannot rule out some scattered low clouds
developing across the southern terminals towards daybreak.
Scattered convection may develop Tuesday afternoon and evening but
will not include thunder at the terminals due to uncertainty in
timing and coverage.
&&
.PREV DISCUSSION... /ISSUED 931 PM CDT MON SEP 15 2014/
UPDATE...
Hurricane Odile continues to move to the north-northwest over the
southern Baja Peninsula this evening, fighting against the mid-
level ridge anchored over the southern CONUS. Abundant mid/upper-
level moisture is emanating from this system, moving north and
east into West TX. A band of very light rain showers continues
to drift from west to east across the Concho Valley and Heartland,
essentially running from San Angelo to Brownwood. Additional
isolated showers have developed farther north from near Rotan to
Haskell. The environment remains convectively unstable with
theta-e decreasing with height through approximately 500 mb, but
large scale ascent is somewhat weak. There really isn`t much of a
forcing mechanism and MUCAPE values remain less than 1000 J/kg
(per RAP Mesoanalysis). A cold front to the northwest of the area,
running from near Clovis, NM to Gage, OK, continues to mover very
slowly to the south, but shouldn`t reach the forecast area
tonight.
PoPs were maintained in the 20-30% range overnight but the thunder
was removed from the forecast. Any precipitation that develops
overnight should remain light, with QPF amounts typically under
1/10 of an inch. Wind/sky grids were also modified but overnight
temperatures remain on track.
Johnson
PREV DISCUSSION... /ISSUED 624 PM CDT MON SEP 15 2014/
AVIATION...
/00Z TAFS/
Mainly VFR conditions expected at the terminals the next
24 hours. Abundant mid and upper level clouds will remain over the
area tonight into Tuesday. A few light showers will be possible at
the KBBD terminal this evening and have included a TEMPO group for
a couple of hours. Widespread stratus appears unlikely late
tonight into Tuesday morning due to extensive mid and high
cloudiness but cannot rule out some scattered low clouds
developing across the southern terminals towards daybreak.
Scattered convection may develop Tuesday afternoon but will not
include thunder at the terminals due to uncertainty in timing and
coverage.
PREV DISCUSSION... /ISSUED 344 PM CDT MON SEP 15 2014/
SHORT TERM...
(Tonight and Tuesday)
As of 3 PM...scattered light rain showers were moving east across
portions of the Heartland between Cross Plains and Cherokee.
These showers will exit the area by late afternoon. Abundant mid
and high level moisture associated with Hurricane Odile will
continue to advect in from the west tonight and Tuesday. A weak
cold front is currently moving south across the Texas Panhandle
and northwest Oklahoma. This front will continue slowly south
overnight and should reach Haskell and Throckmorton counties
around 3 AM. The front is expected to stall along or just north of
I-20 Tuesday morning, before washing out during the afternoon
hours. The best chance for rainfall overnight will be across the
Big Country, mainly after midnight as the front enters the area.
Maintaining chance POPs for Tuesday as weak shortwave energy from
the remnants of Odile move across the tropical airmass in place
across West Texas. Additional convection will also be possible due
to outflow boundary interactions along and south of the decaying
front. Low temperatures tonight will be near 70. Went slightly
lower than guidance for highs on Tuesday, with temperatures
topping out in the lower to middle 80s.
LONG TERM...
(Tuesday night into Monday)
Tropical moisture will remain over West Central Texas this week,
as Hurricane Odile weakens to depression over Baja California.
While the main remnants of Odile will stay west and north of the
region, weak disturbances will likely ripple eastward across West
Central Texas, especially Wednesday afternoon into Thursday,
Precipitable Water increases to 2 inches at this time, bringing
the potential for localized heavy rainfall. Rainfall amounts,
however remain uncertain, as high cloudiness from Odile remnants
may reduced daytime heating, and thus instability and rainfall
amounts. Rainfall amounts of 1/4 to 1/2 inch are certainly
possible however.
Keeping rain chances in Friday into Saturday with moist tropical
airmass over the region. Any weak disturbance could produce
isolated showers.
Cold front indicated this weekend. GFS model has it moving
through Saturday night/Sunday morning, while the EC is 24 hours
slower. WPC extended discussion indicated a 50-50 blend of the
two models, so best chance of the front would be on Sunday.
Locally heavy rainfall is possible as the front at moves through
the tropical air mass, but uncertainly remains on its timing.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 68 85 70 87 69 / 30 40 30 40 60
San Angelo 69 85 71 87 71 / 30 40 30 50 60
Junction 69 86 72 87 71 / 20 30 30 40 60
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
303 AM CDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT TUE SEP 16 2014
LATEST 07Z SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER
WESTERN IOWA. SUBSIDENCE UNDERNEATH HIGH PRESSURE IS ALLOWING FOR
MOSTLY CLEAR SKIES ACROSS THE AREA PER LATEST SATELLITE IMAGERY.
WITH THE CLEAR SKIES AND LIGHT WINDS ACROSS THE FORECAST AREA...FOG
HAS FORMED ALONG THE WISCONSIN RIVER VALLEY...PARTS OF CENTRAL
WISCONSIN AND PARTS OF SOUTHEAST MINNESOTA.
MAIN FORECAST CONCERNS ONCE AGAIN IS FOG POTENTIAL TONIGHT IN RIVER
VALLEYS AND CENTRAL WISCONSIN. TODAY...SURFACE RIDGE DOMINATES THE
REGION. SUBSIDENCE UNDER SURFACE WILL PROVIDE MOSTLY SUNNY SKIES AND
SEASONABLE TEMPERATURES. THE LATEST 16.00Z GFS BUFKIT SOUNDINGS
CONTINUE TO SHOW WINDS LESS THAN 10 KNOTS UP TO 1000 FEET AND
DEVELOP INVERSION. ONCE AGAIN...WITH THE CLEAR SKIES AND LIGHT
WINDS...EXPECT FOG TO DEVELOP AFTER 08Z IN RIVER VALLEYS AND THE
CENTRAL WISCONSIN.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 303 AM CDT TUE SEP 16 2014
FOG POTENTIAL CONTINUES FOR WEDNESDAY NIGHT INTO THURSDAY MORNING IN
RIVER VALLEYS...AS THE 16.0ZZ GFS/ECMWF/NAM CONTINUE SHOW HIGH
PRESSURE DOMINATING THE UPPER MIDWEST AND GREAT LAKES REGION.
HOWEVER...THE 16.00Z GFS/NAM/ECMWF INDICATE A VERY WEAK FRONT TO
PUSH SOUTH INTO CENTRAL WISCONSIN WEDNESDAY EVENING/WEDNESDAY
NIGHT. THIS WEAK FRONT PRODUCES A THIN LAYER OF MOISTURE/CLOUDS
AROUND 850MB ACROSS THE CENTRAL INTO NORTH CENTRAL WISCONSIN
WEDNESDAY NIGHT(00-12Z THURSDAY). THIS MOISTURE/CLOUDS WILL
INHIBIT ANY FOG FORMATION OVER CENTRAL WISCONSIN. THE 16.00Z NAM
IS MORE PROGRESSIVE AND ADVECTS THE MOISTURE/CLOUDS FARTHER WEST
AND POTENTIALLY TO THE MISSISSIPPI RIVER. FOR NOW...WILL CONTINUE
WITH THE MENTION OF PATCHY TO AREAS OF FOG IN THE RIVER
VALLEYS...HOWEVER WILL CONTINUE TO MONITOR IF STRATUS/CLOUDS
DEVELOP OVER CENTRAL WISCONSIN.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THURSDAY NIGHT INTO
SATURDAY NIGHT. THE LATEST 16.00Z GFS/GEM/ECMWF ARE TRENDING TOWARDS
A SLOWER AND FARTHER WEST/NORTH SOLUTIONS WITH THE FIRST IMPULSE TO
IMPACT THE AREA THURSDAY NIGHT AND FRIDAY PER DPROG/DT. THE MODELS
ARE SUGGESTING THE LIFT/MOISTURE TRANSPORT AND CONVERGENCE TO BE
FOCUSED OVER CENTRAL MINNESOTA AND NORTHERN WISCONSIN THURSDAY NIGHT
INTO FRIDAY...AS SHORTWAVE RIDGE REMAINS IN CONTROL OVER SOUTHERN
MINNESOTA AND SOUTHERN WISCONSIN. THIS COULD RESULT IN DRY
WEATHER CONDITIONS ACROSS THE SOUTHERN PART OF THE FORECAST AREA
AND BETTER PRECIPITATION CHANCES OVER THE NORTHERN HALF FRIDAY.
THEN FOCUS TURNS TO FRIDAY NIGHT INTO SATURDAY...AS THE 16.00Z
GFS/GEM/ECMWF ARE IN AGREEMENT DIGGING UPPER LEVEL TROUGH OVER THE
UPPER MIDWEST AND PUSHING SHORTWAVE ENERGY OVER THE FORECAST AREA.
THE MODELS INDICATE DECENT MOISTURE TRANSPORT/CONVERGENCE AND LIFT
ASSOCIATED WITH SHORTWAVE TROUGH/SURFACE COLD FRONT FRIDAY NIGHT
INTO SATURDAY. WILL CONTINUE WITH HIGHER PRECIPITATION CHANCES
DURING THIS TIME FRAME. THE 16.00Z GFS CONTINUES TO SHOW ENOUGH
INSTABILITY AND SHEAR FRIDAY NIGHT INTO SATURDAY...TO POTENTIALLY
HAVE A FEW OF THE THUNDERSTORMS BECOME SEVERE.
SURFACE RIDGE BUILDS INTO THE NORTHERN PLAINS AND THE GREAT LAKES
REGION LATE SUNDAY INTO MONDAY AND PROVIDE DRY WEATHER CONDITIONS
ACROSS THE FORECAST AREA. COOLER AIR WILL FILTER IN BEHIND THE
SURFACE FRONT/SHORTWAVE TROUGH AND TEMPERATURES SHOULD BE NEAR
NORMAL BY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CDT MON SEP 15 2014
THE MAIN AVIATION CONCERN IS THE VALLEY FOG POTENTIAL AT KLSE.
MORNING RAINS/CLOUDS GAVE WAY TO SCATTERED CLOUDS EARLY THIS
EVENING. T/TD SPREAD AT 03Z ONLY 3 F. WINDS WILL BE LIGHT AND
VARIABLE THROUGH THE OVERNIGHT. NEARLY A SLAM DUNK FOR VALLEY FOG.
THE DRAWBACK WILL BE THE DEPTH OF THE LIGHT WIND LAYER. LATEST RAP
SUGGESTS THE LAYER COULD REACH 1400 FT...BUT HAS SHOWN A LOT OF
VARIABILITY OVER ITS PAST FEW RUNS. 00Z NAM12 BUFKIT SOUNDING
STRETCHES TOWARD 2000 FT...AND HOLDS ALL NIGHT. HRRR NOT AS DEEP BUT
ALSO HOLDS ALL NIGHT. THIS NAM/HRRR SCENARIO WOULD FAVOR AT LEAST AN
HOUR OF 1/4SM. MEANWHILE...WINDS ARE BLOWING THE FLAG AROUND AT
GRANDAD/S BLUFF...AROUND 600 FT ABOVE THE VALLEY FLOOR...WHILE VAD
WIND PROFILERS HAVE SHOWN AN INCREASE TO 20-30 KTS AT 2 KFT OVER THE
LAST FEW HOURS. TOUGH CALL. CONFIDENCE LOWERED DUE TO THE DIFFERING
OPINIONS ON HOW THIS WIND LAYER WILL PLAY OUT. GOING TO LEAN TOWARD
FOG MOVING ACROSS KLSE FOR NOW...ALTHOUGH FOR A SHORT PERIOD. OBS
AND WIND FIELDS WILL BE MONITORED CLOSELY THROUGH THE OVERNIGHT.
CONCERNS FOR VALLEY FOG AT KLSE WILL CONTINUE TUE NIGHT...WITH A
SIMILAR SETUP...AND SIMILAR DETRACTOR. NAM12 BUFKIT SOUNDINGS PAINT
A SHALLOW LIGHT WIND LAYER...WHICH IS GENERALLY AN INHIBITOR TO
DENSE VALLEY FOG. BCFG PROBABLY A GOOD WAY TO COVER THE POTENTIAL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR WIZ017-029-034-
042>044.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1130 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 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CDT MON SEP 15 2014
THE MAIN AVIATION CONCERN IS THE VALLEY FOG POTENTIAL AT KLSE.
MORNING RAINS/CLOUDS GAVE WAY TO SCATTERED CLOUDS EARLY THIS
EVENING. T/TD SPREAD AT 03Z ONLY 3 F. WINDS WILL BE LIGHT AND
VARIABLE THROUGH THE OVERNIGHT. NEARLY A SLAM DUNK FOR VALLEY FOG.
THE DRAWBACK WILL BE THE DEPTH OF THE LIGHT WIND LAYER. LATEST RAP
SUGGESTS THE LAYER COULD REACH 1400 FT...BUT HAS SHOWN A LOT OF
VARIABILITY OVER ITS PAST FEW RUNS. 00Z NAM12 BUFKIT SOUNDING
STRETCHES TOWARD 2000 FT...AND HOLDS ALL NIGHT. HRRR NOT AS DEEP BUT
ALSO HOLDS ALL NIGHT. THIS NAM/HRRR SCENARIO WOULD FAVOR AT LEAST AN
HOUR OF 1/4SM. MEANWHILE...WINDS ARE BLOWING THE FLAG AROUND AT
GRANDAD/S BLUFF...AROUND 600 FT ABOVE THE VALLEY FLOOR...WHILE VAD
WIND PROFILERS HAVE SHOWN AN INCREASE TO 20-30 KTS AT 2 KFT OVER THE
LAST FEW HOURS. TOUGH CALL. CONFIDENCE LOWERED DUE TO THE DIFFERING
OPINIONS ON HOW THIS WIND LAYER WILL PLAY OUT. GOING TO LEAN TOWARD
FOG MOVING ACROSS KLSE FOR NOW...ALTHOUGH FOR A SHORT PERIOD. OBS
AND WIND FIELDS WILL BE MONITORED CLOSELY THROUGH THE OVERNIGHT.
CONCERNS FOR VALLEY FOG AT KLSE WILL CONTINUE TUE NIGHT...WITH A
SIMILAR SETUP...AND SIMILAR DETRACTOR. NAM12 BUFKIT SOUNDINGS PAINT
A SHALLOW LIGHT WIND LAYER...WHICH IS GENERALLY AN INHIBITOR TO
DENSE VALLEY FOG. BCFG PROBABLY A GOOD WAY TO COVER THE POTENTIAL.
&&
.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.....RIECK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
947 AM EDT TUE SEP 16 2014
.SYNOPSIS...
LOW PRESSURE ALONG THE SOUTHERN NEW JERSEY COAST WILL MOVE SOUTH
OF LONG ISLAND THIS AFTERNOON. HIGH PRESSURE WILL BUILD IN FROM
THE WEST ON WEDNESDAY. A WEAK COLD FRONT WILL CROSS THE AREA ON
THURSDAY. THEN ANOTHER LARGE AREA OF HIGH PRESSURE WILL MOVE IN
FOR THE REMAINDER OF THE WEEK AND BRING DRY AND PLEASANT
CONDITIONS. A COLD FRONT FROM THE WEST MAY REACH THE EASTERN
SEABOARD SUNDAY NIGHT INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM ESTF HAD INCREASED SKYCOVER IN THE FCST THIS MORNING
BASICALLY ALONG AND E OF 75W LONGITUDE. WE MAY NEED TO ADD MORE
CLOUDS AS THE DAY WEARS ON. THE HRRR WAS RIGHT AND NEW RAIN IS NOW
REDEVELOPING OVER EASTERN NJ AS OF 930 AM. ITS BECOME A BIT OF A
SHABBY MORNING IN NJ AND EXTREME EAST CENTRAL PA WITH LOTS OF LOW
CLOUDINESS. SPRINKLES MAY LINGER INTO EARLY AFTN COASTAL NJ...OR A
A LINE OF SHOWERS MAY DEVELOP AND MOVE SEWD THERE BETWEEN 11AM-
1PM.
OTRW EXPECT DRYING IMPROVING CONDITIONS LATER THIS AFTERNOON
ACROSS THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS THE HIGH CONTINUES TO BUILD IN, EXPECT CLEARING SKIES.
A COOL NIGHT IS UPCOMING...SIMILAR TO YDY MORNING WHEN KMPO HAD 38
FOR A LOW AND WIDESPREAD COUNTRYSIDE 40S OCCURRED.
THERE IS A SMALL THREAT THAT THE POCONOS AND NW NJ COULD REACH FROST
ADVISORY CRITERIA TONIGHT, BUT AT THIS POINT, FORECAST TEMPERATURES
ARE A FEW DEGREES ABOVE CRITERIA.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
OVERALL, A QUIET PD ACRS THE REGION.
WK HIGH PRES WILL BUILD INTO THE REGION ON WED. IT WILL QUICKLY BE
DISPLACED BY A WEAK COLD FRONT THAT IS FORECAST TO CROSS THE AREA
WED NIGHT INTO THU. THIS CFP IS EXPECTED TO BE DRY. ALL OF THE
MDLS, WITH THE EXCEPTION OF THE GFS DO NOT GENERATE ANY PRECIP,
AND HAVE GONE WITH THE MDL CONSENSUS.
BEHIND THIS CFP A LARGE AREA OF HIGH PRES WILL MOVE TO THE N AND
EVENTUALLY NE FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND,
KEEPING IT DRY AND PLEASANT. A MORE NE TO E FLOW WILL EVENTUALLY
DEVELOP WITH TIME.
BY SUN NIGHT INTO MON, LOW PRES WILL BE MOVG ACRS ERN CAN AND ITS
ASSOCD CDFNT WILL APPROACH FROM THE W AND CROSS THE REGION DURG
MON. THIS APPEARS TO BE OUR NEXT BEST SHOT OF PRECIP, IN WHAT IS
AN OTHERWISE DRY FCST.
TEMPS WILL GENLY BE A TAD BELOW NRML THRU THE ERLY PORTION OF THE
PD, WARMING TO NR NRML BY THE END OF THE EXTENDD.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS
THROUGH 16Z...IFR-MVFR CIGS IN LEFTOVER MORNING SHOWERS MOISTURE
FROM JUST N OF KPHL THRU NJ. OTRW FOR KPHL KILG KRDG AND KABE VFR
SCT-BKN DEVELOPING AOA 3500 FT. LIGHT WIND.
AFTER 16Z...SCT-BKN CLOUDS AOA 3500 FT EXPECTED EVERYWHERE THOUGH
MVFR CIGS MAY LINGER KACY AND KMIV. LIGHT NW WIND.
TONIGHT...VFR LIGHT WIND.
OUTLOOK...
WED - SAT...VFR. N WIND WILL BECOME MORE NE TO E AND COULD BECOME
A BIT GUSTY THU NIGHT INTO FRI, ESPECIALLY ALG THE CST. MDT TO
HIGH CONFIDENCE.
&&
.MARINE...
WINDS WILL TURN NW BEHIND DEPARTING COASTAL SNJ WEAK LOW PRESSURE
TODAY. NW WINDS COULD GUST UP TO 20 KT BUT WILL REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA. SEAS-SWELLS COULD BUILD 3 OR 4 FT TONIGHT,
BUT WILL REMAIN BELOW ADVISORY CRITERIA.
FEELING SOME SUBTLE SWELL FROM DISTANT EDOUARD AT THIS TIME...14
SECOND 1 FT.
THE PRIMARY SWELL FROM EDOUARD IS STILL EAST OF 70W AND STRUGGLING
TO EDGE WESTWARD. 44066 - TEXAS TOWER BUOY 75 NM EAST OF THE NJ
COAST HAS HAD A STEADY STATE 2 FT SWELL THE PAST 24 HOURS.
OTHER THAN THE RAIN AND LOW CLOUDS ALONG THE NJ COASTS...ITS A
GOOD DAY TO BE OUT.
OUTLOOK...
WED-THU...SCA MAY BE NEEDED FOR PORTIONS OF THE ATLANTIC WATERS
EITHER FOR HAZARDOUS SEAS WED INTO THU BUT CONFIDENCE REMAINS LOW.
WW GUID MAY BE TOO HIGH. HRCN EDOUARD IS FCST TO MAKE ITS CLOSEST
APPROACH TO THE MID ATLC CST DURG THIS TIME, BUT REMAIN WELL
OFFSHORE (E OF 60 W). PLEASE SEE THE LATEST NHC ADVISORIES FOR THE
MOST UP-TO-DATE INFORMATION ON EDOUARD.
FRI-SAT...STRONGER ONSHORE NORTHEAST FLOW IS EXPECTED TO DEVELOP
AND SCA LEVEL WIND GUSTS AND/OR SEAS IS ANTICIPATE ONCE AGAIN,
WITH HIGH PRES OVER NEW ENG. WINDS GUSTS AROUND 25 KNOTS AND SEAS
OF 5 TO 6 FEET ARE POSSIBLE.
&&
.RIP CURRENTS...
THERE IS A MODERATE RISK OF RIP CURRENTS TODAY PRIMARILY DUE TO
INCREASED LONG PERIOD SWELLS FROM HURRICANE EDOUARD. THE ENHANCED
RIP CURRENT RISK WILL PROBABLY CONTINUE THROUGH TOMORROW AND POSSIBLY
THURSDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG/DRAG 947A
NEAR TERM...DRAG 947A
SHORT TERM...JOHNSON
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG 947A
MARINE...DRAG/JOHNSON/NIERENBERG 947A
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
600 AM CDT TUE SEP 16 2014
...UPDATE TO AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 114 AM CDT TUE SEP 16 2014
THIS MORNING WILL BE PLAGUED BY WIDESPREAD FOG AND LOW CEILINGS.
THERE IS ABUNDANT MOISTURE AT THE LOWER LAYERS AND THE LIGHT WINDS
WILL ALLOW THE TEMP/DEWPOINT DEPRESSION TO WITHER TO 1 TO 2 DEGREES
APART. THIS FOG SHOULD START IN OUR NORTHWEST ZONES FIRST NEAR
SYRACUSE AND SCOTT CITY, AND SPREAD SOUTHEASTWARD BETWEEN 09Z AND
12Z. FOR NOW, I ONLY EXPECT VISIBILITIES TO BE REDUCED TO LESS THAN
1 MILE, SO A FOG ADVISORY DOES NOT SEEM WARRANTED, BUT SHOULD BE
WATCHED AND MONITORED. THIS FOG AND THE LOW CLOUDS WILL DELAY THE
DAY TIME HEATING, BUT THE WARM ADVECTION WILL WIN OUT LATER THIS
MORNING. THE WARMEST TEMPERATURES WILL BE NEAR THE COLORADO
BORDER, WHERE A LEE SIDE TROUGH WILL EXIST. MID 80S SHOULD BE
REALIZED THERE, WHILE COOLER HIGH PRESSURE TO OUR EAST WILL RESULT
IN HIGH TEMPERATURES IN THE MID 70S NEAR HAYS AND LACROSSE. THE
CLOUDS WILL LINGER OVER OUR EASTERN ZONES THROUGH MUCH OF THE
AFTERNOON. LIGHT AND VARIABLE WINDS EARLY TODAY WILL BECOME FROM
THE SOUTH AT ONLY THE 10 TO 12 MPH RANGE THIS AFTERNOON. I HAVE
CHOSE TO FOLLOW THE HRRR AND RUC MODELS, WHICH KEEP ANY PRECIPITATION
TODAY TO OUR SOUTH. OF NOTE HOWEVER, ARE BOTH THE HIRESW-NMM AND
THE HIRESW-ARW MODELS WHICH BOTH BRING LIGHT PRECIPITATION TO OUR
SOUTHERN CWA THIS AFTERNOON, BASICALLY SOUTH OF HIGHWAY 50.
I EXPECT NEARLY CLOUD-FREE SKIES OVERNIGHT WITH LIGHT SOUTH WINDS AT
6 TO 8 MPH. THE TEMP/DEWPOINT SPREAD IS EXPECTED TO BE GREATER
TONIGHT, SO I DON`T EXPECT AS MUCH FOG OR STRATUS. THERE COULD BE
SOME 3 TO 5SM FOG, ESPECIALLY IN OUR EAST, BUT I DON`T THINK THIS
IS WORTH MENTIONING. MINIMUM TEMPERATURES SHOULD BE SIMILAR TO
THIS MORNING, RANGING FORM THE LOWER 60S NORTH OF I-70 TO THE MID
60S IN THE BARBER AND COMANCHE COUNTY AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 322 AM CDT TUE SEP 16 2014
MEDIUM RANGE MODELS INDICATE A NORTHWESTERLY FLOW ALOFT PREVAILING
ACROSS THE WESTERN HIGH PLAINS WEDNESDAY AS UPPER LEVEL RIDGING
SLOWLY EDGES EASTWARD ACROSS THE INTERMOUNTAIN WEST INTO THE WESTERN
HIGH PLAINS. THIS WILL LEND TO DRIER CONDITIONS ACROSS MUCH OF
WESTERN KANSAS EARLY IN THE PERIOD. HOWEVER, ISOLATED THUNDERSTORMS
CANNOT BE RULED OUT ACROSS PORTIONS OF CENTRAL AND SOUTH CENTRAL
KANSAS WEDNESDAY NIGHT AS A SURFACE LOW BECOMES MORE ORGANIZED
ACROSS WESTERN KANSAS. A NEAR STATIONARY FRONTAL BOUNDARY IS
PROJECTED TO EXTEND EAST-SOUTHEAST OFF THE SURFACE LOW ACROSS
SOUTHERN KANSAS PROVIDING INCREASED CONVERGENCE. ALONG WITH A
STRONGER FLOW ALOFT, STEEPENING LOW/MID LEVEL LAPSE RATES AND
INCREASED INSTABILITY MAY BE ENOUGH TO SUPPORT THUNDERSTORM
DEVELOPMENT IN THE VICINITY OF THE BOUNDARY WEDNESDAY EVENING INTO
EARLY THURSDAY MORNING. OTHERWISE, DRIER CONDITIONS WILL PREVAIL
ACROSS WESTERN KANSAS THROUGH THURSDAY NIGHT AS THE UPPER LEVEL
RIDGE TRANSITIONS ACROSS THE WESTERN HIGH PLAINS INTO THE CENTRAL
PLAINS.
MORE WIDESPREAD RAINFALL WILL BE POSSIBLE ACROSS WESTERN AND
CENTRAL KANSAS LATE FRIDAY INTO SATURDAY AS THE REMNANTS OF
TROPICAL STORM ODILE ARE PROJECTED TO LIFT NORTHEAST ACROSS THE
DESERT SOUTHWEST THURSDAY ON THE BACKSIDE OF THE UPPER LEVEL RIDGE
SHIFTING EASTWARD INTO THE CENTRAL PLAINS. THE REMNANTS WILL LIFT
FURTHER NORTHEAST INTO THE HIGH PLAINS OF EXTREME EASTERN COLORADO
AND WESTERN KANSAS FRIDAY. MEANWHILE, AN UPPER LEVEL SHORTWAVE
TROUGH IS EXPECTED TO SWING EASTWARD ACROSS THE NORTHERN PLAINS
FRIDAY NIGHT INTO SATURDAY SENDING AN ATTENDANT COLD FRONT SURGING
SOUTHEASTWARD INTO WESTERN AND CENTRAL KANSAS WHILE ADDITIONAL
MOISTURE POOLS AHEAD OF THE APPROACHING FRONT WITHIN A
SOUTHEASTERLY UPSLOPE FLOW. AS A RESULT, SHOWERS AND ISOLATED
THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
WITH THE ONSET OF PRECIP TOWARD FRIDAY AFTERNOON/EVENING. SHOWERS
AND ISOLATED THUNDERSTORMS ARE EXPECTED TO SPREAD EASTWARD INTO
CENTRAL KANSAS LATE FRIDAY NIGHT INTO SATURDAY. BASED ON PW
VALUES AND QPF FIELDS, SOME AREAS COULD SEE IN EXCESS OF ONE HALF
INCH OF RAINFALL BY EARLY SATURDAY MORNING WITH HIGHER AMOUNTS
FURTHER TO THE EAST WHERE INCREASED MOISTURE WILL BE MORE READILY
AVAILABLE.
ABOVE NORMAL TEMPERATURES ARE LIKELY WEDNESDAY AS A SURFACE LOW
DEEPENS ACROSS THE HIGH PLAINS ENHANCING AN ALREADY PREVAILING
SOUTHERLY FLOW INTO WESTERN KANSAS. THE GFS/ECMWF ARE IN FAIR
AGREEMENT SHOWING H85 TEMPERATURES CLIMBING A LITTLE ABOVE 20C
ACROSS CENTRAL KANSAS TO NEAR 25C CLOSER TO THE COLORADO BORDER IN
SOUTHWEST KANSAS. WITH MODEL SOUNDINGS INDICATING STEEP LOW LEVEL
LAPSE RATES BY WEDNESDAY AFTERNOON, LOOK FOR HIGHS WELL UP INTO
THE 80S(F) WITH NEAR 90F IN SOME LOCATIONS. WARM AIR ADVECTION
WILL CONTINUE THURSDAY AS THE SOUTHERLY FLOW PERSISTS RAISING
HIGHS A FEW DEGREES WITH A FEW MORE LOWER 90S(F) POSSIBLE.
SLIGHTLY LOWER HIGH TEMPERATURES CAN BE EXPECTED FRIDAY AS CLOUD
COVER BECOMES MORE WIDESPREAD WITH AREAS OF PRECIP POSSIBLE AS
EARLY AS FRIDAY AFTERNOON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 600 AM CDT TUE SEP 16 2014
MVFR CIGS WILL LINGER IN THE VICINITY OF ALL TAF SITES THROUGH
LATE MORNING AS A STRATUS DECK MOVES SLOWLY EAST ACROSS WESTERN
KANSAS. VFR CONDITIONS WILL RETURN WEST TO EAST THIS AFTERNOON
AS THE STRATUS DECK LIFTS AND DISSIPATES. WINDS WILL BECOME
SOUTHEASTERLY 5 TO 15KT THIS MORNING AS THE SURFACE HIGH IN
EASTERN KANSAS SHIFTS SLOWLY EASTWARD. WINDS WILL BECOME MORE
SOUTHERLY THIS AFTERNOON INCREASING TO AROUND 15 TO 25KT AS
A DEVELOPING LEE SIDE TROUGH STRENGTHENS ACROSS EASTERN
COLORADO.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 64 89 63 / 10 10 0 10
GCK 82 61 89 62 / 10 0 0 10
EHA 86 62 89 62 / 10 0 0 10
LBL 83 63 90 64 / 10 0 0 10
HYS 73 61 84 63 / 10 10 0 20
P28 79 66 89 63 / 10 10 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...JJOHNSON
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
728 AM EDT TUE SEP 16 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 319 AM EDT TUE SEP 16 2014
AN AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION TODAY FROM THE
WEST. THIS SYSTEM WILL HELP TO CREATE AREAS OF DENSE FOG THIS
MORNING. THE FOG WILL DISSIPATE LATER THIS MORNING GIVING WAY TO
MOSTLY SUNNY SKIES AND BELOW NORMAL TEMPERATURES. A WEAK COLD
FRONT WILL SLIP SOUTH OF THE REGION WEDNESDAY NIGHT. THEN A VERY
STRONG HIGH PRESSURE SYSTEM WILL BUILD DOWN FROM THE NORTH FOR THE
END OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 319 AM EDT TUE SEP 16 2014
THE MAIN CHALLENGE DEALS WITH THE POTENTIAL FOR DENSE FOG EARLY
THIS MORNING. OVERALL IT LOOKS LIKE MOST LOCATIONS WILL SEE DENSE
FOG THIS MORNING. AS A RESULT I ISSUED A DENSE FOG ADVISORY.
THICK FOG ALREADY EXISTS IN PLACES...ESPECIALLY NORTH OF
INTERSTATE 96 AS OF 3 AM. HRRR RUC SHOWS THE SKIES TEMPORARILY
CLEARING OUT ACROSS SOUTHERN LOWER MI WITH THE THICK FOG BUILDING
SOUTHWARD THROUGH THE REMAINDER OF THE NIGHT. THE FOG IS SHOWN TO
SLOWLY DISSIPATE LATE THIS MORNING. AS A RESULT WITH AN ELEVATED
RISK FOR HAZARDOUS CONDITIONS FOR THE MORNING COMMUTE AND AT BUS
STOPS...I DECIDED THAT AN ADVISORY WOULD BE THE BEST WAY TO GO.
THE REMAINDER OF THE FORECAST IS RELATIVELY QUITE WITH A WEAK DRY
COLD FRONTAL PASSAGE WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 319 AM EDT TUE SEP 16 2014
THE MAIN FOCUS OF THE LONG TERM PORTION OF THE FCST CONTINUES TO BE
THE SYSTEM THAT IS FCST TO MOVE THROUGH THE AREA THIS WEEKEND AND
THE ASSOCIATED PCPN CHCS WITH IT.
WE SHOULD SEE ONE MORE DRY AND QUITE MILD DAY AT THE BEGINNING OF
THE PERIOD ON FRI. THE FAR NW CORNER COULD SEE A LOW CHC OF SOME
RAIN LATE ON FRI AFTERNOON. WE WILL SEE AN UPPER RIDGE IN THE
PROCESS OF WEAKENING AS IT MOVES EAST INTO THE AREA DURING THE DAY
ON FRI. THIS WILL KEEP MOST OF THE AREA DRY. INCREASING SRLY RETURN
FLOW WILL BRING A NICE SURGE OF WARMTH INTO THE AREA.
THE THREAT OF RAIN WILL GRADUALLY INCREASE STARTING FRI NIGHT AND
WILL PEAK ON SAT NIGHT. WE WILL SEE THE INITIAL SFC LOW WITH THE
NEXT FRONT STAY WELL NORTH INTO CANADA...TAKING WITH IT THE BEST LOW
LEVEL JET AND MOISTURE TRANSPORT WITH IT. THE FRONT WILL APPROACH
THE AREA LATE ON SAT AND THEN MOVE THROUGH THE AREA ON SAT NIGHT AND
INTO THE FIRST PART OF SUN. WE COULD SEE ANOTHER VERY MILD DAY ON
SAT IF WE SEE A DECENT AMOUNT OF SUNSHINE AND H850 TEMPS IN THE MID
TEENS C.
THE INTERESTING THING ABOUT THE FRONTAL PASSAGE WILL BE THAT SOME OF
THE MODELS ARE INDICATING THAT SOME REMNANTS FROM THE TROPICAL
SYSTEM ODILE COULD INTERACT WITH THE FRONT. THIS COULD LEAD TO A BIT
MORE RAIN THAN CURRENTLY FCST AS THE MODELS TYPICALLY UNDER FCST THE
AMOUNT OF HEAT AND MOISTURE WITH SYSTEMS OF A TROPICAL ORIGIN THAT
BECOME EXTRA-TROPICAL. THIS WILL BE SOMETHING TO WATCH.
WE SHOULD DRY OUT DURING THE SECOND HALF OF SUN AS WE SEE THE DRY
SLOT MOVE THROUGH THE AREA. WE COULD SEE ONE MORE MILD DAY ON SUN
BEFORE THE COLD CONVEYOR BELT WRAPS INTO THE AREA ON MON. THE MODELS
ARE SHOWING H850 TEMPS DROPPING DOWN CLOSE TO ZERO C ON MON. THERE
IS FAIRLY DECENT AGREEMENT WITH THE STRENGTH AND TIMING OF THIS LOW
AND THE COLD AIR BEHIND IT. WE HAVE ADDED SOME LAKE EFFECT RAIN
SHOWERS FOR MON ALONG THE SHORE WITH AN EXPECTED NNW WIND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 716 AM EDT TUE SEP 16 2014
DENSE FOG WILL CONTINUE TO IMPACT TAF SITES FOR MUCH OF THE
MORNING WITH MANY SITES IN SOUTHWEST MI LIFR TO START. CONDITIONS
WILL GENERALLY START IMPROVING AFTER 14Z...BUT IFR COULD EASILY
PERSIST THROUGH 15Z. BY 18Z ENOUGH MIXING EXPECTED TO ALLOW FOR
CONDITIONS TO IMPROVE TO VFR. WILL NEED TO MONITOR THE FOG
POTENTIAL FOR LATER TONIGHT. RIGHT NOW THE POTENTIAL IS TOO LOW TO
ADD IT TO THE FORECAST.
&&
.MARINE...
ISSUED AT 319 AM EDT TUE SEP 16 2014
MAY END UP WITH WAVES APPROACHING SMALL CRAFT ADVISORY CRITERIA
WEDNESDAY NIGHT INTO THURSDAY AROUND BIG SABLE POINT AS A STRONGER
NORTHEAST FLOW DEVELOPS. WILL CONTINUE TO MONITOR THIS POTENTIAL.
OTHERWISE THE MARINE FORECAST LOOKS QUIET AT THIS POINT.
&&
.HYDROLOGY...
ISSUED AT 319 AM EDT TUE SEP 16 2014
WILL NEED TO MONITOR THE HEAVY RAIN POTENTIAL OVER THE WEEKEND AS
A COLD FRONT MOVES THROUGH AND TAPS TROPICAL MOISTURE. OTHERWISE
NO MAJOR RAIN SYSTEMS EXPECTED THROUGH FRIDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...NJJ
AVIATION...MJS
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
639 AM EDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE SEP 16 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE AND ASSOC JET
MAX MOVING THROUGH NRN ONTARIO WHICH HAS SUPPORTED A CLUSTER OF SHRA
ALONG COLD FRONTAL BOUNDARY OVER NW ONTARIO AS NOTED ON CANADIAN
RADAR MOSIAC. CLEAR SKIES AND LIGHT WINDS UNDER SFC HIGH PRES RIDGE
HAVE ALLOWED FOR MIN TEMPS TO DROP NEAR OR BLO THE FREEZING MARK FOR
MANY OF THE TYPICAL INTERIOR COLD SPOT LOCATIONS ACROSS UPPER MI
EARLY THIS MORNING.
TODAY...PLENTY OF SUNSHINE THIS MORNING WILL GIVE WAY TO INCREASING
CLOUDS LATE IN THE AFTERNOON AS A COLD FRONT SAGS SOUTHWARD THROUGH
LAKE SUPERIOR. MODELS INDICATE THAT ANY LIGHT PCPN ASSOCIATED WITH
THE FRONT AND ASSOC 900-800 MB FGEN SHOULD STAY NORTH OF THE
KEWEENAW UNTIL EVENING. OTHERWISE...EXPECT TEMPERATURES TO REBOUND
CLOSER TO SEASONAL AVERAGES WITH HIGHS IN THE MID 60S AND PERHAPS
EVEN REACHING UPPER 60S FOR A FEW DOWNSLOPING LOCATIONS OVER NCNTRL
UPPER MI IN DEVELOPING WSW FLOW AHEAD OF THE FRONT.
TONIGHT...THE COLD FRONT WILL SAG SOUTH INTO MAINLY THE NW AND ERN
CWA BY LATE EVENING. MODELS SHOW THAT THE BEST MOISTURE WILL BE N OF
THE FRONT WITH THE BEST FORCING/Q-VECT CONV TO BE OVER NW AND ERN
CWA LATE TONIGHT AHEAD OF A SHORTWAVE MOVING ACROSS WRN ONTARIO AND
IN THE RIGHT ENTRANCE REGION OF ASSOC 100+ KT 3H JET MAX MOVING INTO
WRN QUEBEC. WILL MAINTAIN SLIGHT CHC TO LOW CHC POPS FOR SHRA OVER
MAINLY THE KEWEENAW AND FAR NE CWA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE SEP 16 2014
A COLD FRONT THAT MOVED INTO THE THE CWA TUE EVENING WILL HAVE A
WNW-ESE ORIENTATION OVER THE CENTRAL CWA AT 12Z WED...AND WILL MOVE
S OF THE CWA BY WED EVENING. BEST MOISTURE WILL BE N OF THE FRONT
AND BEST FORCING WILL BE OVER THE NRN CWA LATE TUE NIGHT INTO WED
MORNING AS AN UPPER TROUGH MOVES ACROSS THE AREA. A SFC HIGH WILL
MOVE IN QUICKLY BEHIND THE UPPER TROUGH/COLD FRONT...USHERING IN DRY
AND COLDER AIR. WHAT THIS MEANS FOR PRECIP CHANCES IS THAT THE
GREATEST POPS WILL BE OVER THE NRN CWA WED MORNING WITH THE UPPER
TROUGH ENERGY. PRECIP CHANCES ARE LOWER TO THE S...BUT SLIGHT CHANCE
TO LOW END CHANCE POPS WILL FOLLOW THE POST-FRONTAL MOISTURE S
THROUGH THE AFTERNOON. HIGH TEMPS WILL RANGE FROM AROUND 50 OVER NRN
UPPER MI NEAR LAKE SUPERIOR TO AROUND 60 OVER THE SCENTRAL.
THE SFC HIGH CENTER WILL MOVE ACROSS FAR NERN LAKE SUPERIOR WED
NIGHT INTO THU MORNING. PREVIOUS MODEL RUNS SHOWED A NARROW AREA OF
WAA AND GREATER MOISTURE OVER THE WRN CWA...BUT NEWEST RUNS SHOW
THAT BEING WELL SW OF THE CWA. THEREFOR...WHILE ERN UPPER MI SHOULD
STILL BE THE COLDEST DUE TO THE PROXIMITY TO THE HIGH AND COLDEST
AIRMASS...THE WRN CWA COULD ALSO SEE NEAR FREEZING TEMPS. LOOKS LIKE
FROST IS A GOOD POSSIBILITY ACROSS MUCH OF INLAND UPPER MI.
LOW LEVEL RETURN FLOW WILL BEGIN ON THU BETWEEN THE DEPARTING SFC
HIGH AND A BROAD TROUGH MOVING INTO THE WRN PLAINS. NO PRECIPITATION
IS EXPECTED THU DUE TO LINGERING DRY AIR. HIGH TEMPS WILL BE 1-2
DEGREES WARMER THAN WED.
WAA/ISENTROPIC ASCENT REALLY INCREASE LATE THU NIGHT AND FRI AS THE
SFC HIGH TO THE E SLOWS AND THE TROUGH TO THE W ACCELERATES
EASTWARD. THE WAA AND POSSIBLY SOME SHORTWAVE ENERGY WILL LIKELY
LEAD TO PRECIP ACROSS MUCH OF THE CWA FRI INTO FRI NIGHT. MODELS ARE
IN GOOD AGREEMENT THROUGH FRI...BUT BECOME MUCH HARDER TO USE FRI
NIGHT INTO SAT DUE /AT LEAST PARTLY/ TO WITH PHASING OF REMNANTS OF
HURRICANE ODILE WITH THE EXISTING TROUGH. WHILE MODELS DO ALL SHOW A
GOOD AMOUNT OF QPF FOR SAT...THEY DO NOT AGREE WELL IN THE FEATURES
CAUSING THE PRECIP. WHILE POPS WILL REMAIN HIGH ON SAT...SIGNIFICANT
UNCERTAINTY STILL EXISTS. WILL KEEP THUNDER CHANCES GOING FOR FRI
AFTERNOON THROUGH SAT EVENING...BUT AM NOT OVER CONCERNED ABOUT
HEAVY RAIN UNLESS REMNANTS OF ODILE END UP MOVING INTO THE AREA
/WHICH IS HIGH UNCERTAIN/. WARMEST CONDITIONS OF THE PERIOD ARE
EXPECTED ON SAT AS 850MB TEMPS INCREASE TO GREATER THAN 15C.
MUCH COLDER AIR MOVES IN WITH NW FLOW SUN AND MON...EVEN BRINGING
THE POSSIBILITY OF LAKE EFFECT RAIN SHOWERS BOTH DAYS. AGREE WITH
PREVIOUS SHIFT THAT ECMWF SHOULD BE SET ASIDE BECAUSE IT IS A COLD
OUTLIER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 636 AM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE FORECAST
PERIOD. WSW WINDS WILL GUST AT OR ABOVE 20 KT AT IWD AND CMX BY LATE
MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE SEP 16 2014
EXPECT WSW WINDS TO 25 KTS THROUGH EARLY AFTERNOON AHEAD OF A COLD
FRONT APPROACHING FROM ONTARIO. WINDS WILL DIMINISH AS FRONT MOVES
OVERHEAD TONIGHT BUT THEN INCREASE TO UP TO 25 KTS FROM THE
NORTHEAST IN THE WAKE OF THE COLD FRONT ON WEDNESDAY...MAINLY OVER
WRN LAKE SUPERIOR. 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. WINDS
WILL LIKELY DIMINISH ON SATURDAY AS LOW PRES TROUGH FROM THE PLAINS
MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR MIZ002-
004-005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
701 AM CDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM CDT TUE SEP 16 2014
THERE ARE PRIMARILY 3 MAIN ISSUES DURING THESE NEXT 24
HOURS...SOME OF WHICH MAY BE BIGGER DEALS THAN OTHERS.
THE FIRST INVOLVES WHETHER OR NOT A POTENTIALLY EXPANSIVE AREA OF
LOWER STRATUS CURRENTLY POSITIONED A FEW COUNTIES SOUTH-SOUTHWEST
OF THE CWA WILL SPREAD NORTHEAST OVER AT LEAST PARTS OF THE CWA
TODAY AND IF SO...HOW MUCH IMPACT TO HIGH TEMPS COULD OCCUR.
COMPARED TO 12-24 HOURS AGO...CONFIDENCE HAS WANED A BIT ON
WHETHER THESE CLOUDS REALLY WILL END UP AFFECTING MUCH OF THE AREA
AND FOR HOW LONG. ISSUE NUMBER 2 CONCERNS THUNDERSTORM CHANCES
TONIGHT...AS ALTHOUGH THE MAJORITY OF THE AREA CARRIES A PRETTY
GOOD CHANCE OF REMAINING STORM FREE...AT LEAST A SLIGHT CHANCE IS
REFLECTED FOR ROUGHLY THE SOUTHEAST 1/4 OF THE CWA POST-MIDNIGHT.
THIRDLY...ALTHOUGH MODELS/GUIDANCE ARE BY NO MEANS
UNANIMOUS...CONCERNS ARE INCREASING FOR AT LEAST SOME COVERAGE OF
POTENTIALLY IMPACTFUL FOG ISSUES LATE TONIGHT/EARLY WED MORNING
ESPECIALLY WITHIN THE WESTERN HALF OF THE CWA AS BREEZES AVERAGE
LIGHT AND SURFACE DEWPOINTS RISE 10+ DEGREES ABOVE CURRENTLY
OBSERVED VALUES...INDICATIVE OF INCREASING LOW LEVEL MOISTURE.
STARTING OFF WITH THE HERE AND NOW AS OF 08Z/3AM...A VERY QUIET
NIGHT CONTINUES ACROSS THE CWA UNDER NEARLY CLOUD-FREE SKIES. AT
THE SURFACE...A ROUGHLY 1025 MILLIBAR RIDGE AXIS IS CENTERED
SQUARELY OVER THE NEB/IA BORDER AREA...PROVIDING NEAR-CALM TO
LIGHT SOUTHEASTERLY BREEZES OF GENERALLY 6 MPH OR LESS. GIVEN THE
FAIRLY IDEAL RADIATIONAL COOLING CONDITIONS...TEMPS HAVE DROPPED
SOMEWHERE INTO THE 40S ACROSS MOST OF THE CWA AS EXPECTED...WITH
EVEN A FEW SITES VERY NEAR THE CWA SUCH AS COLUMBUS/BROKEN BOW AT
LEAST BRIEFLY INTO THE UPPER 30S. AUTOMATED AIRPORT SITES SUGGEST
THAT SOME VERY PATCHY...PRIMARILY LIGHT FOG LIKELY EXISTS OUT
THERE IN A FEW SPOTS...BUT BARRING NOTICEABLE CHANGES ITS
COVERAGE/IMPACT DOES NOT APPEAR WORTHY OF A FORMAL FORECAST
MENTION...WITH SOMEWHAT BETTER CHANCES OF A FEW DECENT VISIBILITY
REDUCTIONS POSSIBLY FOCUSING CLOSER TO THE NEB/IA BORDER. LOOKING
ALOFT TO THE MID-UPPER LEVELS...SHORT TERM MODEL DATA AND WATER
VAPOR IMAGERY INDICATES FAIRLY UNEVENTFUL AND BROAD NORTHWESTERLY
FLOW ALOFT OVER THE CENTRAL PLAINS...STEERED BETWEEN A LARGE SCALE
TROUGH OVER EASTERN CANADA AND A RIDGE EXTENDING NORTHWARD OVER
THE WESTERN CONUS. WAY OFF TO THE SOUTHWEST...TROPICAL STORM ODILE
SLOWLY CHURNS NORTHWEST UP THE BAJA PENINSULA.
LOOKING AHEAD AND STARTING WITH THE VERY SHORT TERM THROUGH
ROUGHLY SUNRISE...THE SURFACE RIDGE AXIS WILL CONTINUE A VERY SLOW
EASTWARD DEPARTURE...ALLOWING LIGHT SOUTH WINDS TO BECOME A BIT
BETTER ESTABLISHED ACROSS MUCH OF THE CWA. AS MENTIONED
ABOVE...THE BIGGEST SHORT TERM MYSTERY INVOLVES THE FATE OF THE
NORTHWEST KS STRATUS DECK...AS LAST FEW 11-3.9 MICRON SATELLITE
FRAMES SHOW ITS LEADING EDGES STARTING TO MAKE A PUSH TOWARD THE
SOUTHWESTERN FRINGES OF THE CWA...BUT UNLIKELY TO POTENTIALLY
INFILTRATE MUCH OF THE LOCAL AREA BEFORE SUNRISE. ALTHOUGH A FEW
PLACES MAY START STEADYING OUT A BIT ON THE TEMP-FALL...MOST OF
THE CWA IS ON TRACK TO REALIZE OVERNIGHT LOWS BETWEEN 41-46
DEGREES.
FOR THE DAYTIME HOURS 12Z-00Z/7AM-7PM...THE FORECAST REMAINS DRY
AS AM NOT EXPECTING THE VERY HIGH BASED WESTERN NEB SPRINKLES
CURRENTLY NOTED ON RADAR TO HAVE ANY IMPACT LOCALLY. THE MID-
UPPER LEVEL PICTURE REMAINS FAIRLY STEADY-STATE UNDER A BAND OF
MODESTLY STRONG NORTHWESTERLY FLOW...AS A RATHER SUBTLE LOW-
AMPLITUDE DISTURBANCE GRADUALLY APPROACHES THE LOCAL AREA FROM THE
NORTHWEST. AT THE SURFACE...THE COMBINATION OF A TIGHTENING
PRESSURE GRADIENT BETWEEN THE DEPARTING RIDGE AND MODEST HIGH
PLAINS PRESSURE FALLS TO THE WEST...ALONG WITH MIXING UP INTO A
WEAK-MODEST LOW LEVEL JET WILL PROMOTE INCREASING SOUTHERLY
BREEZES...ESPECIALLY DURING THE MID-MORNING TO MID-AFTERNOON
HOURS...WITH SUSTAINED SPEEDS GENERALLY 10-15 MPH AND GUSTS TO
AROUND 20 MPH ESPECIALLY WITHIN THE WESTERN 1/2 OF THE CWA. NOT TO
KEEP BEATING THE DRUM ON THIS ISSUE...BUT THE UNCERTAINTY IN THE
PRESENCE OR LACK THEREOF OF THE POTENTIAL INVADING STRATUS DECK
CERTAINLY RAISES SOME CONSIDERABLE QUESTIONS ON SKY COVER AND
RESULTANT TEMPS...WITH LIKELY AROUND A 5-DEGREE TEMP BUST
POTENTIAL ON THE LINE. BASED ON THE LATEST 06Z NAM 850 MILLIBAR
RELATIVE HUMIDITY PROGS...AT LEAST A LIMITED COVERAGE OF PARTLY-
MOSTLY CLOUDY SKIES SHOULD SLOWLY OVERTAKE THE CWA FROM SOUTHWEST-
NORTHEAST TODAY...WHILE THE LATEST HRRR LOW CLOUD COVER PRODUCT
SUGGESTS STRATUS COULD BE A MORE MINIMAL ISSUE AS ALTHOUGH IT
STILL BRINGS IT INTO MAINLY THE SOUTHWEST 1/2 TO 1/3 OF THE CWA IT
DIMINISHES IT AREA WITH TIME AND EVEN MIXES IT OUT ALMOST
COMPLETELY IN THE AFTERNOON. NOT SURPRISINGLY...THE OFFICIAL SKY
COVER FORECAST IS A HEDGE...SUGGESTING THAT THE DAY AS A WHOLE
STARTS OUT MOSTLY SUNNY IN MOST AREAS BUT THEN BECOMES AT LEAST
PARTLY CLOUDY WITH AT LEAST A BRIEF FEW HOURS OF MOSTLY CLOUDY
PASSING THROUGH. EVEN WITHOUT LOWER STRATUS...A FEW DECENT PATCHES
OF MID LEVEL CLOUDS COULD ALSO WORK OVERHEAD FROM THE NORTHWEST.
STAY TUNED FOR PLENTY OF SKY COVER FINE TUNING BY DAY SHIFT. HIGH
TEMP-WISE...FOLLOWED A BLEND OF VARIOUS MODELS/GUIDANCE TO YIELD
AROUND A 2-3 DEGREE RISE FROM PREV FORECAST...WHICH PUTS MOST OF
THE CWA IN THE 69-73 RANGE BUT WITH SLIGHTLY WARMER GENERALLY
74-77 IN FAR SOUTHWEST ZONES. BY THIS AFTERNOON SURFACE DEWPOINTS
SHOULD HAVE RISEN BACK UP SOMEWHERE IN THE 50S...HIGHEST
SOUTHWEST.
THIS EVENING-TONIGHT...THE MID-UPPER LEVEL STORY INVOLVES
CONTINUED FAIRLY STEADY-STATE NORTHWESTERLY FLOW ALOFT AS A VERY
LOW-AMPLITUDE/CHANNELED SHORTWAVE TROUGH SLIDES CLIPS THROUGH
MAINLY JUST TO THE NORTHEAST OF THE CWA ALONG A TRACK FROM THE
DAKOTAS THROUGH IA INTO NORTHERN MO. AS THIS WAVE PASSES BY...IT
WILL INDUCE A MODEST INCREASE IN THE LOW LEVEL JET AND ASSOCIATED
THETA-E ADVECTION/ISENTROPIC LIFT THAT WILL GRADUALLY VEER FROM
SOUTHWESTERLY TO MORE WESTERLY...ALTHOUGH THE MAIN NOSE OF THIS
FORCING LOOKS TO AIM EASTERN KS AND NOT SO MUCH LOCALLY. AS A
RESULT...THE MAJORITY OF BOTH DETERMINISTIC AND HIGHER RES-
SIMULATED REFLECTIVITY MODELS SUCH AS THE 4KM WRF-NMM FOCUS
OVERNIGHT CONVECTION AT LEAST A FEW COUNTIES EAST-SOUTHEAST OF THE
CWA. HOWEVER...GIVEN THAT THE PREVIOUS FORECAST ALREADY WAS
CARRYING A SLIGHT SHOWER/STORM CHANCE IN SOUTHEAST ZONES AND THAT
THE GFS IN PARTICULAR STILL TRIES TO INITIATE STORMS IN THIS
AREA...HAVE HELD ONTO THIS SLIGHT CHANCE MAINLY SOUTHEAST OF A
GENEVA-PLAINVILLE LINE POST-MIDNIGHT...BUT REMOVED ANY PRECIP
CHANCES EARLIER IN THE EVENING GIVEN THAT LIFT DOES NOT APPEAR
SUFFICIENT TO GENERATE CONVECTION BEFORE THEN. SHOULD ANY STORMS
BE REALIZED...CERTAINLY A FEW STRONG UPDRAFTS CAPABLE OF
PRODUCING AT LEAST NEAR-SEVERE HAIL CANNOT BE RULED OUT GIVEN THE
06Z NAM SUGGESTION OF UP TO AROUND 1500 J/KG MUCAPE IN THE
850-700MB LAYER AND AROUND 40KT OF DEEP LAYER SHEAR. AS A
RESULT...WILL CONTINUE TO MENTION NICKEL SIZE HAIL POTENTIAL IN
THE LOCAL HAZARDOUS WEATHER OUTLOOK IN SOUTHEAST AREAS...DESPITE
THE FACT THAT THE LATEST SPC DAY 1 OUTLOOK REMOVED THE 5 PERCENT
SEVERE PROBABILITY CONTOUR FROM THE CWA THAT HAD BEEN PRESENT ON
THE FORMER DAY 2 OUTLOOK. AGAIN THOUGH...NO MATTER WHAT THE
MAJORITY OF THE CWA SHOULD GET THROUGH THE NIGHT DRY. TURNING TO
THE SURFACE SITUATION...GENERALLY 5-8 MPH SOUTHEASTERLY BREEZES
THIS EVENING SHOULD BECOME EVEN LIGHTER AND MORE EASTERLY AFTER
MIDNIGHT. ASSUMING THAT OVERNIGHT SKIES AVERAGE NO WORSE THAN
PARTLY CLOUDY IN THE WAKE OF POTENTIAL EASTWARD-EXITING STRATUS
FROM THE DAYTIME HOURS...THE STAGE COULD BE SET FOR SOME
POTENTIALLY DECENT AT-LEAST-LIGHT FOG FORMATION...AND MAYBE SOME
MORE IMPACTFUL FOG ESPECIALLY WITHIN THE WESTERN 1/2 OF THE CWA
PER THE LATEST SREF VISIBILITY PROBABILITY PRODUCTS. EXPERIENCE
HAS SHOWN THAT FOG IS ALMOST NEVER A "SURE THING" UNTIL IT
ACTUALLY FORMS...BUT FELT IT WOULD BE PRUDENT TO INTRODUCE A
GENERIC PATCHY FOG WORDING TO ALL AREAS LATE TONIGHT...AND A
SOMEWHAT HARDER-HITTING AREAS OF FOG MENTION TO WESTERN COUNTIES.
ITS JUST TOO SOON TO SAY WHETHER OR NOT FOG COULD CAUSE IMPACTFUL
ISSUES FOR THE WED MORNING COMMUTE. AS FOR LOW TEMPS...MADE VERY
LITTLE CHANGE HERE...AS THE INCREASED LOW LEVEL MOISTURE SHOULD
HELP HOLD UP LOWS GENERALLY 5-10 DEGREES HIGHER THAN THIS
MORNING...AND AM CALLING FOR A RANGE FROM NEAR-50 FAR
NORTH...LOW-MID 50S CENTRAL AND NEAR 60 FAR SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 435 AM CDT TUE SEP 16 2014
THE WARMEST DAY OF THE NEXT 7 DAYS WILL BE FRIDAY WITH HIGHS IN THE
MID 80S AHEAD OF A COLD FRONT. THE BEST CHANCE OF
SHOWERS/THUNDERSTORMS CURRENTLY APPEARS TO BE ASSOCIATED WITH THAT
COLD FRONTAL PASSAGE FRIDAY NIGHT INTO THE FIRST HALF OF SATURDAY.
THE COOLEST DAY OF THE WEEK WILL ACTUALLY BE TODAY WITH HIGHS OF 70
TO 75. SO OVERALL THIS WILL BE A RATHER NICE WEEK WITH HIGHS NEAR
NORMAL FOR THIS TIME OF YEAR...WHICH IS GENERALLY IN THE UPPER 70S.
WEDNESDAY/WEDNESDAY NIGHT...AN UPPER LEVEL RIDGE WILL BE CENTERED
OVER THE ROCKIES WITH NORTHWESTERLY FLOW ALOFT ACROSS THE CENTRAL
PLAINS. THERE WILL BE DECENT INSTABILITY AND WIND SHEAR ACROSS OUR
FORECAST AREA...BUT FORCING IS RATHER WEAK. THERE MAY BE A WEAK
UPPER WAVE RIDING DOWN THE EAST SIDE OF THE RIDGE OR PERHAPS
SLIGHTLY BETTER LIFT AFTER DARK WEDNESDAY NIGHT AS A WEAK LOW LEVEL
JET LIFTS OVER THE EAST SOUTHEAST SFC FLOW. HOWEVER...THE BETTER LOW
LEVEL JET SET UP APPEARS TO BE TO OUR SOUTHEAST OVER NORTHEAST
KANSAS. SO OVERALL...FORCING JUST SEEMS RATHER QUESTIONABLE AND WILL
ONLY CARRY LOWER END POPS BEGINNING WEDNESDAY NIGHT WITH THE REALITY
BEING MOST LOCATIONS WILL MORE LIKELY THAN NOT BE DRY.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES WILL DECREASE. A FEW
FORECAST MODELS ARE STILL HINTING AT LOW END CHANCES OF
PRECIPITATION ACROSS OUR FORECAST AREA...BUT AM NOT VERY OPTIMISTIC
THAT THERE WILL BE MUCH OUT THERE GIVEN THE RIDGE MOVING IN.
THEREFORE...DECREASED OUR POPS AND DOWNGRADED SHOWER AND
THUNDERSTORM CHANCES TO JUST ISOLATED SPRINKLES.
FRIDAY THROUGH SATURDAY...AS MENTIONED ABOVE...FRIDAY WILL BE THE
WARMEST DAY OF THE NEXT 7 DAYS AS GUSTY SOUTHERLY WINDS PUMP WARMER
AIR INTO THE REGION AHEAD OF AN APPROACHING COLD FRONT. AN
INTERESTING WRINKLE IN THIS FORECAST IS WHAT WILL HAPPEN WITH THE
REMNANTS OF HURRICANE ODILE...WHICH IS CURRENTLY LOCATED OVER THE
BAJA PENINSULA OF MEXICO. THE 00Z GFS AND 00Z ECMWF BOTH BRING
REMNANT MOISTURE FROM THIS DECAYING TROPICAL SYSTEM NORTH NORTHEAST
INTO THE CENTRAL PLAINS...WHERE IT WILL WORK INTO AN UPPER LEVEL
STORM SYSTEM THAT IS TRACKING EAST THROUGH THE CENTRAL PLAINS. THERE
ARE STILL PLENTY OF QUESTIONS WITH REGARD TO THE TIMING OF WHEN THE
TROPICAL MOISTURE PLUME WILL ARRIVE AND HOW THAT WILL INTERACT WITH
OUR MID LATITUDE UPPER TROUGH. THE MOST LIKELY TIME FOR
PRECIPITATION WILL BE FROM FRIDAY NIGHT THROUGH SATURDAY
MORNING...WITH THE SYSTEM EXITING TO OUR EAST BY SATURDAY AFTERNOON.
TEMPERATURES WILL BE SLIGHTLY COOLER SATURDAY BEHIND THE COOL
FRONT...BUT NOTHING MAJOR WITH HIGHS ONLY AROUND 5F COOLER.
SUNDAY THROUGH MONDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH DRY WEATHER LIKELY FOR OUR FORECAST AREA. HIGH
TEMPERATURES WILL BE NEAR NORMAL IN THE 70S.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY)
ISSUED AT 700 AM CDT TUE SEP 16 2014
CONFIDENCE REMAINS FAIRLY HIGH IN VFR CEILING PREVAILING THROUGH
THE PERIOD AND VFR VISIBILITY PREVAILING THROUGH THE MAJORITY OF
THE PERIOD. ALSO...OTHER THAN MAYBE A ROGUE SPRINKLE TODAY IT
SHOULD REMAIN PRECIPITATION-FREE. HOWEVER...FOCUSING IN MORE
DETAIL ON CEILING...THERE REMAINS UNCERTAINTY REGARDING WHETHER
OR NOT A POTENTIALLY EXPANSIVE CEILING RATHER CLOSE TO THE VFR-
MVFR HEIGHT BREAKPOINT COULD MOVE IN FOR AT LEAST A FEW HOURS AT
SOME POINT TODAY...AS THE LEADING EDGES OF THIS STRATUS LAYER HAS
NOW GOTTEN WITHIN 80-100 MILES SOUTHWEST OF THE TERMINALS. THERE
ARE STILL QUESTIONS WHETHER OR NOT THIS CLOUD DECK WILL OVERSPREAD
KEAR/KGRI...BUT WILL ASSUME FOR NOW THAT IT WILL MOVE IN...AND IN
FACT HAVE REVERSED GROUND FROM 06Z FORECAST AND SPED UP THE ONSET
A FEW HOURS BASED ON LATEST SATELLITE AND SHORT-TERM MODEL TRENDS.
VISIBILITY-WISE...NOT EXPECTING ANY ISSUES UNTIL LATE TONIGHT
TOWARD THE END OF THE PERIOD...WHEN CONDITIONS COULD BE SETTING UP
FOR AT LEAST MVFR IN DEVELOPING FOG...AND POTENTIALLY WORSE. FOR
NOW WILL START THE BALL ROLLING WITH A 3SM MENTION BEYOND 09Z. AS
FOR SURFACE WINDS...BREEZES WILL STEADILY INCREASE THIS MORNING AS
MIXING DEEPENS...WITH MUCH OF THE DAY FEATURING A SOUTHERLY
SUSTAINED BREEZE OF 10-15KT WITH SLIGHTLY HIGHER GUSTS...BEFORE
WINDS SUBSIDE A BIT FROM A PREVAILING SOUTH- SOUTHEAST DIRECTION
IN THE EVENING...AND THEN BECOME VERY LIGHT EASTERLY TO VARIABLE
LATE TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
730 AM EDT TUE SEP 16 2014
.SYNOPSIS...A COLD FRONT APPROACHING THE REGION FROM THE WEST
WILL TRACK SLOWLY SOUTHWARD THROUGH THE CAROLINAS LATER TODAY
AND TONIGHT. THE FRONT WILL GRADUALLY MOVE OFFSHORE THE
SOUTHEAST COAST ON WEDNESDAY AND THURSDAY AS HIGH PRESSURE
STRENGTHENS OVER THE GREAT LAKES AND EXTENDS SOUTHWARD THROUGH THE
MID ATLANTIC.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM TUESDAY...
TODAY...WEAK MID-UPPER LEVEL DISTURBANCE EXITING THE REGION EARLY
THIS MORNING. PATCHES OF LIGHT RAIN OR SHOWERS SHOULD CONTINUE TO
DECREASE IN COVERAGE/INTENSITY THROUGH DAYBREAK. ABUNDANT LOW LEVEL
MOISTURE SHOULD RESULT IN THE FORMATION OF A LOW CLOUD DECK BY
DAYBREAK. WEAK SUBSIDENCE IN THE WAKE OF THIS EXITING FEATURE
COMBINED WITH A DOWNSLOPE COMPONENT TO THE 925-850MB WIND AFTER 12Z
SHOULD AID TO DIMINISH/DISSIPATE THE WIDESPREAD LOW CLOUDS BY LATE
MORNING-MID DAY.
HEATING OF THE ATMOSPHERE IN COMBINATION WITH RESIDUAL MOISTURE AND
THE APPROACH OF ANOTHER MID-UPPER LEVEL DISTURBANCE SHOULD TRIGGER
SCATTERED SHOWERS-ISOLATED THUNDERSTORMS. LATEST ROUND OF WRF MODEL
RADAR PRESENTATIONS ALONG WITH THE HRRR FAVOR INITIAL DEVELOPMENT IN
THE WESTERN PIEDMONT AROUND MID AFTERNOON. THE 00Z GFS (AND MORE SO
THE 00Z NAM) INDICATE SLIGHT INSTABILITY OVER THE WESTERN PIEDMONT
ALONG WITH SOME BULK SHEAR OF SUFFICIENT MAGNITUDE (25-30KTS) TO
ALLOW FOR SOME LOOSELY ORGANIZED CONVECTION. SOME WRF MODELS SUGGEST
BROKEN BAND OF CONVECTION MAKING IT INTO THE TRIANGLE REGION BEFORE
WEAKENING/DISSIPATING. CONSIDERING THE LACK OF RADAR ECHOES UPSTREAM
ASSOCIATED WITH THE NEXT DISTURBANCE...NOT READY TO INCREASE ANY
MORE THAN CURRENT 20-40 PERCENT. HOWEVER...HAVE SHIFTED POP EMPHASIS
MORE TO THE WESTERN PIEDMONT RATHER THAN THE SOUTHERN COASTAL PLAIN
DUE TO BETTER PROXIMITY OF UPPER LEVEL SUPPORT.
MOS GUIDANCE CONTINUES TO ADVERTISE MAX TEMPS SOLIDLY IN THE MID
80S. THESE TEMPS ACHIEVABLE IF LOW CLOUDS DEPART/DISSIPATE PRIOR TO
15Z AND SCATTERED CONVECTION HOLDS OFF UNTIL MID AFTERNOON. FAVOR
MAX TEMPS SLIGHTLY COOLER THAN MOS (LOWER 80S NW TO MID 80S
ELSEWHERE).
TONIGHT...SCATTERED CONVECTION WILL GRADUALLY WEAKEN WITH LOSS OF
HEATING AND EXITING OF MID LEVEL DISTURBANCE. STILL...COULD SEE A
FEW SHOWERS PERSIST PAST MIDNIGHT TOT EH EAST-SOUTH OF RDU.
CLOUDINESS AND LACK OF APPRECIABLE LOW LEVEL CAA SUGGEST MIN TEMPS A
FEW DEGREES WARMER THAN EARLIER THINKING. MIN TEMPS LOW-MID 60S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 330 AM TUESDAY...
WEDNESDAY...ABUNDANT LOW LEVEL MOISTURE TRAPPED BENEATH A LOW LEVEL
INVERSION SHOULD RESULT IN EXTENSIVE CLOUDINESS OVER MOST OF THE
REGION WEDNESDAY MORNING...AND POTENTIALLY LINGERING INTO THE
AFTERNOON ACROSS THE PIEDMONT. (THIS MAY BE CLASSIFIED AS A HYBRID
OR INSITU DAMMING EVENT THOUGH PARENT HIGH RELATIVELY WEAK AND QUITE
TRANSITORY). IF EXTENSIVE CLOUDS DO LINGER PAST MID DAY ACROSS THE
PIEDMONT...THIS MAY CREATE A DIFFERENTIAL HEATING BOUNDARY BETWEEN
THE PIEDMONT AND THE SANDHILLS/SOUTHERN COASTAL PLAIN. THE APPROACH
OF YET ANOTHER DISTURBANCE IN THE WEST-NW FLOW ALOFT INTERACTING
WITH THIS FEATURE MAY TRIGGER MORE SCATTERED CONVECTION...MAINLY
OVER THE SE THIRD OF OUR FORECAST AREA. THE LOW LEVEL STABLE AIR
MASS SUGGEST MAINLY PATCHY STRATIFORM RAIN OVER THE NORTHERN
PIEDMONT (OR ELEVATED SHOWERS. SINCE LEANING TOWARD MORE CLOUDINESS
ACROSS THE PIEDMONT...HAVE LOWERED MAX TEMPS A COUPLE OF DEGREES BUT
RAISED MAX TEMPS TO NEAR/ABOVE 80 OVER THE SE COUNTIES.
CONTINUED CYCLONIC FLOW ALOFT WILL MAINTAIN CLOUDINESS WEDNESDAY
NIGHT ALONG WITH A SMALL THREAT FOR SHOWERS...MAINLY EAST OF HIGHWAY
1. MIN TEMPS SEVERAL DEGREES COMPARED TO THE PREVIOUS NIGHT. MIN
TEMPS UPPER 50S NW TO LOWER 60S SE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...
THE MEDIUM RANGE WILL FEATURE A LONGWAVE TROUGH THAT WILL MOVE
OFFSHORE THE EAST COAST THU AND CONSEQUENTLY YIELD TO RISING HEIGHTS
ALOFT AS A FLAT MID LEVEL RIDGE RIDGE BRIEFLY BUILDS EAST FROM THE
SOUTHERN PLAINS AND LOWER MS VALLEY FRI-SAT. THE RE-ESTABLISHMENT OF
A WESTERN NOAM RIDGE WILL THEN RESULT IN DOWNSTREAM TROUGH
AMPLIFICATION FROM SOUTH-CENTRAL CANADA TO THE EAST-CENTRAL US SUN-
MON...THE LEAD SHORTWAVE TROUGH OF WHICH WILL INCLUDE THE REMNANTS
OF TROPICAL STORM ODILE.
MEANWHILE AT THE SFC...A CANADIAN-SOURCE SFC HIGH (AROUND 1030 MB)
WILL BUILD FROM CENTRAL CANADA TO THE CANADIAN MARITIMES AND RIDGE
SOUTH/SOUTHWESTWARD IN DAMMING ORIENTATION EAST OF THE APPALACHIANS
THU THROUGH THE WEEKEND...FOLLOWED BY A COLD FRONTAL PASSAGE -
DRIVEN BY THE AFOREMENTIONED RE-AMPLIFICATION OF THE LONGWAVE TROUGH
INTO THE EAST-CENTRAL US - ON MON.
THE RESULT WILL BE A RELATIVELY PROLONGED PERIOD OF EAST TO
NORTHEAST LOW LEVEL FLOW AND ASSOCIATED BELOW NORMAL TEMPERATURES...
TEMPERED FURTHER BY PERIODS OF BKN MULTI-LAYERED CLOUD
COVER...THROUGH EARLY THIS WEEKEND. THE RELATIVE GREATEST CLOUD
COVERAGE WILL LINGER THU (FROM WED NIGHT)...WHEN A LINGERING CHANCE
OF SHOWERS WILL ALSO REMAIN...MAINLY OVER THE COASTAL WHERE A
DEPARTING H85 WAVE/TROUGH WILL AUGMENT WEAK FORCING ALOFT ATTENDING
A PAIR OF SHORTWAVE TROUGHS FORECAST TO CROSS THE CAROLINAS AND
MIDDLE ATLANTIC THROUGH MID-LATE THU AFTERNOON. UNDER ASSOCIATED
VARIABLY CLOUDY SKY COVER...WITH RELATIVE GREATEST COVERAGE
EAST...TEMPERATURES SHOULD FALL ABOUT A CATEGORY OR SO SHY OF WHAT
FULL SUN THICKNESSES OF AROUND 1385 METERS WOULD OTHERWISE SUPPORT.
COOL AGAIN OVERNIGHT WITH DEEP LAYER DRYING/FALLING PRECIPITABLE
WATER VALUES TO AROUND AN INCH...AS THE AFOREMENTIONED MID LEVEL
RIDGE EXPANDS EASTWARD AND CAUSES - LOWS MIDDLE 50S TO AROUND 60.
OTHERWISE...THE INCREASING INFLUENCE OF THE RIDGING AT THE SFC AND
ALOFT SHOULD PROMOTE DRY CONDITIONS FRI-SUN...THOUGH WITH
TEMPERATURES MODERATING ONLY SLOWLY THROUGH THE 70S...TO AROUND 80
DEGREES BY SUN. THE PASSAGE OF THE SFC COLD FRONT EARLY NEXT WEEK
SHOULD THEN SUPPORT A CHANCE OF SHOWERS IN CENTRAL NC ON MON. ONCE
THE INHERENT D7 TIMING DIFFERENCES ARE IRONED OUT...A SLIGHT CHANCE
OF THUNDER MAY BE INTRODUCED WITH LATER FORECASTS IF IT APPEARS
FAVORABLE DIURNAL TIMING OF THE FRONTAL PASSAGE WILL OCCUR.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 730 AM TUESDAY...
WIDESPREAD MVFR/IFR CEILINGS WITH AREAS OF MVFR FOG WILL SLOWLY
IMPROVE AFTER 14Z WITH MAINLY VFR CONDITIONS EXPECTED BY 16Z.
SURFACE WINDS WILL BE LIGHT AND VARIABLE...BECOMING NORTH NORTHWEST
AT 7KTS OR LESS AFTER 14Z. THE APPROACH OF A SURFACE COLD FRONT LATE
TODAY AND THIS EVENING WILL LIKELY TRIGGER SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS AROUND MID AFTERNOON IN THE WESTERN PIEDMONT
INCLUDING THE TRIAD TERMINALS. IF THESE SHOWERS HOLD TOGETHER...THEY
WOULD THREATEN THE KRDU VICINITY CLOSE TO UNSET...AND KRWI AND KFAY
DURING THE EVENING HOURS.
VFR CONDITIONS ANTICIPATED TONIGHT THROUGH WEDNESDAY WITH A BRIEF
PERIOD OF MVFR CEILING/VISIBILITY POSSIBLE EARLY WEDNESDAY MORNING.
SCATTERED CONVECTION MAY DEVELOP WEDNESDAY AFTERNOON-WEDNESDAY NIGHT
AS ANOTHER DISTURBANCE MOVES ACROSS THE REGION.
THE PERIOD THURSDAY THROUGH SATURDAY APPEARS TRANQUIL WITH MAINLY
VFR CONDITIONS. A BRIEF PERIOD OF MVFR CEILING OR VISIBILITY MAY
OCCUR EACH MORNING...MAINLY IN THE VICINITY OF KRWI AND KFAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS/VINCENT
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...MWS
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1007 AM CDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 1005 AM CDT TUE SEP 16 2014
BAND OF MID CLOUDS ACROSS MANITOBA INTO FAR NRN MN. AREA DEFINED
WELL BY LATEST RAP MODEL AND SHOWS CLOUDS HOLDING IN THAT AREA
THRU THE DAY. OTHERWISE SHOULD BE SUNNY. TEMPS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 253 AM CDT TUE SEP 16 2014
MAIN CHALLENGE FOR TODAY WILL REVOLVE AROUND THE BAND OF MID
CLOUDS MOVING INTO THE FAR NORTHERN FA NOW. OTHERWISE NEXT CHANCE
OF PCPN LOOKS TO BE SLIGHTLY MORE DELAYED...ARRIVING MORE THU
AFTERNOON INTO THU NIGHT. AS MENTIONED THERE IS A BAND OF MID
CLOUDS NOW MOVING INTO THE LAKE OF THE WOODS REGION. MODELS KEEP
SOME MID LEVEL MOISTURE IN A NW TO SE BAND TODAY...MAINLY
ASSOCIATED WITH THE THERMAL GRADIENT AND A WEAK SHORT WAVE UNDER
THE NORTHWEST FLOW ALOFT. THEREFORE WILL KEEP MORE CLOUDS
MENTIONED IN THE FAR NORTH AND NE. SHOULD SEE MORE SUN IN OTHER
AREAS WITH HIGH TEMPS IN THE MID 60S TO LOW 70S. SOME OF THESE MID
CLOUDS MAY ALSO LINGER INTO TONIGHT IN THE SAME GENERAL AREA ALONG
WITH PRETTY LIGHT WINDS. MAY EVEN BE A FEW SPRINKLES OR LIGHT
SHOWERS AROUND THE LAKE OF THE WOODS REGION SO DID ADD THAT TO THE
FORECAST THERE LATE TONIGHT INTO EARLY WED. THE TIGHTER THERMAL
GRADIENT ALSO PUSHES INTO THE NORTHEAST FA ON WED WHICH SHOULD
BRING A LITTLE COOLER TEMPS TO THE NORTH AND NE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 253 AM CDT TUE SEP 16 2014
START TO SEE RETURN FLOW WED NIGHT WITH STEADY WARM ADVECTION IN
ALL AREAS. THIS WILL SET THU UP TO BE ANOTHER WARM DAY WITH HIGHS
MORE IN THE LOW TO MID 70S. INCREASING SFC PRESSURE GRADIENT
SHOULD ALSO RESULT IN FAIRLY BREEZY SOUTH WINDS. MODELS CONTINUE
TO SCALE BACK ON PCPN CHANCES SO DID REMOVE THEM FROM THE THU
MORNING TIME FRAME. STILL SOME UNCERTAINTY FOR THIS AREA THU
AFTERNOON WITH THE MAIN SFC FOCUS STILL BACK OVER THE WESTERN HIGH
PLAINS. 700MB TEMPS RISE TO +10C OVER MOST OF CENTRAL AND WESTERN
ND WITH VALUES A LITTLE LOWER INTO NORTHWEST MN. THIS MAY CAP ANY
CONVECTION WITH THE SFC FORCING OUT WEST. HOWEVER WITH THE
UNCERTAINTY DID KEEP WITH CONTINUITY AND LEFT THE ISOLATED THUNDER
POTENTIAL THU AFTERNOON. THE WARM 700MB TEMPS CREST OVER THE FA
THU NIGHT ALONG WITH STEADY 850MB WARM ADVECTION/INCREASING
MOISTURE VALUES. THE SFC BOUNDARY WILL ALSO MOVE INTO THE WESTERN
FA BY FRI MORNING BRINGING A LITTLE BETTER CHANCE FOR SHOWERS AND
TSTMS.
FOR FRI THROUGH MON NIGHT...THE PERIOD WILL START WITH SOME SHOWERS
AND STORMS WITH A SHORTWAVE AND DEEPER MOISTURE IN PLACE. EACH MODEL
RUN INDICATES MORE SCATTERED NATURE TO ANY CONVECTION FRIDAY...WITH
THE BEST CHANCES IN THE SOUTH AND EAST. A COOL FRONT WILL MOVE
THROUGH THE REGION ON SAT...AND THERE COULD BE MORE SHOWERS. DRIER
AND SLIGHTLY COOLER WEATHER WILL MOVE IN FOR SUNDAY...BEFORE ANOTHER
WARMING TREND AND DRY WEATHER NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 627 AM CDT TUE SEP 16 2014
SEEING SOME MID LEVEL CLOUDS ALONG THE CANADIAN BORDER OVER TOWARD
THE UPPER AND LOWER RED LAKES. THESE MAY SINK A LITTLE FURTHER
SOUTH BUT WILL LEAVE THEM OUT OF KTVF/KBJI FOR NOW AND LET THE DAY
CREW SEE WHAT HAPPENS WHEN THE SUN COMES OUT. THERE MAY ALSO BE A
FEW LATE MORNING/AFTERNOON CUMULUS BUT IF THESE DO DEVELOP THEY
WOULD BE WELL IN THE VFR RANGE. WINDS OVERALL LOOK PRETTY MINIMAL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...GODON
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
1015 AM PDT TUE SEP 16 2014
.SYNOPSIS...
HIGH PRESSURE ALOFT AND MOIST EAST TO SOUTHEAST FLOW WILL HOT HUMID
CONDITIONS OVER THE REGION TODAY. THERE WILL BE A CHANCE OF
THUNDERSTORMS THIS AFTERNOON OVER THE VALLEYS...MOUNTAINS AND
DESERTS...WITH HIGHEST CHANCES IN THE INLAND EMPIRE. THE MOIST FLOW
WILL CONTINUE WEDNESDAY AND BRING ANOTHER CHANCE OF THUNDERSTORMS
THEN...BUT SOME COOLING WILL OCCUR AS THE HIGH ALOFT WEAKENS. A
RETURN TO ONSHORE FLOW WILL BRING MORE SIGNIFICANT COOLING THURSDAY
AS A TROUGH DEVELOPS OVER THE WEST COAST. THE TROUGH OF LOW PRESSURE
WILL BRING PARTLY CLOUDY CONDITIONS FRIDAY INTO THE WEEKEND WITH
TEMPERATURES MOSTLY NEAR OR A LITTLE ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
STRONG SOUTHEASTERLY MOISTURE SURGE WENT THROUGH THE DESERTS THIS
MORNING AND BROUGHT PRECIPITABLE WATER VALUES NEAR 2 INCHES NEAR THE
SALTON SEA BY MID-MORNING. THIS ALSO BROUGHT STRATUS ALONG THE EAST
SLOPES OF THE MOUNTAINS AND LOCALLY GUSTY EASTERLY WINDS WEST OF THE
MOUNTAINS...WITH LOCAL GUSTS AROUND 40 MPH...INCLUDING AT HIGHLAND
SPRING IN RIVERSIDE COUNTY AND HELLHOLE CANYON AND SILL HILL IN SAN
DIEGO COUNTY. IT GAVE A SPIKE IN THE TEMPERATURES IN THE
VALLEYS...AT 10 AM...WE WERE ALREADY 97 DEGREES AT THE NWS OFFICE IN
RANCHO BERNARDO WITH A DEW POINT OF 73. DUE TO THE MORE HEAT THAN
TUESDAY IN WESTERN SAN DIEGO COUNTY...HAVE EXTENDED THE HEAT
ADVISORY TO THE SAN DIEGO COUNTY COASTAL ZONE FOR TODAY. HIGHEST
TEMPS SHOULD BE IN THE INLAND EMPIRE WHERE LOCAL TEMPS AROUND 108
COULD AGAIN OCCUR...THOUGH 100 DEGREE TEMPS WILL LIKELY OCCUR ON THE
SAN DIEGO COUNTY MESAS AND QUITE A BIT OF ORANGE COUNTY. DUE TO THE
MONSOONAL SURGE...THERE IS A GOOD SURFACE CONVERGENCE ZONE IN THE
INLAND EMPIRE AND WESTERN SAN DIEGO COUNTY...SO THUNDERSTORMS COULD
DEVELOP THERE TODAY. IF TSTORMS DEVELOP IN THE INLAND EMPIRE...HAIL
WOULD BE A THREAT DUE TO THE SHARP DECREASE IN MOISTURE ABOVE 550
MB. HRRR SHOWS THE HIGHEST QPF OVER THE INLAND EMPIRE WHERE LOCAL
RAINFALL COULD EXCEED AN INCH AND COULD BRING LOCALIZED FLOODING.
ALSO...LOCALLY STRONG WINDS COULD OCCUR AS THE STORMS WOULD BE
RELATIVELY HIGH-BASED. ALSO...THUNDERSTORMS COULD DEVELOP OVER THE
MOUNTAINS DUE TO ELEVATED HEATING IN AN UNSTABLE AIRMASS...AND
LOCALLY IN THE DESERTS...THOUGH SUFFACE BOUNDARIES DO NOT LOOK AS
FAVORABLE THERE.
THERE IS NOT TOO MUCH CHANGE IN THE THINKING FOR WED AS FORMER
HURRICANE ODILE IS TRACKING TOWARDS NW SONORA/SE ARIZONA.
PRECIPITABLE WATER VALUES WILL BE AROUND OR A LITTLE ABOVE 1.5
INCHES AT THE COAST AND POSSIBLY APPROACHING 2 INCHES IN THE DESERTS
AND CAPES EASILY OVER 1000 J/KG...WE SHOULD HAVE SCATTERED
THUNDERSTORMS OVER THE MOUNTAINS/DESERTS AND POSSIBLY THE VALLEYS.
MODELS ARE NOT SHOWING MUCH EXPLICIT PRECIP...BUT WE COULD GET
LOCALLY HEAVY RAINS AND LOCAL FLOODING. FLOODING CHANCES DO NOT LOOK
WIDESPREAD ENOUGH FOR A FLASH FLOOD WATCH THOUGH. WE LOSE 2-3 DEG C
OF 850 MB TEMPS WED...SO GENERALLY PLACES SHOULD BE ABOUT 5 DEG F
COOLER...THOUGH WITH HIGH HUMIDITY STILL AROUND...HEAT INDEX VALUES
WILL BE CLOSE TO HEAT ADVISORY THRESHOLDS. WILL EXAMINE FURTHER. FOR
THU...MUCH DRIER AIR COMES IN FROM THE WEST...AND ONSHORE FLOW
DEVELOPS AT THE SURFACE. WE HAVE ALREADY DECREASED MTN/DESERT TSTORM
CHANCES AND MAY ELIMINATE THEM ENTIRELY IN THE AFTERNOON PACKAGE.
MODELS HAVE A CLOSED UPPER LOW OFF THE COAST OVER THE WEEKEND WHICH
COULD BRING SOME CLOUDS...BUT MOISTURE/INSTABILITY LOOK MARGINAL FOR
TSTORMS. BEST CHANCES OF ANY TSTORM ACTIVITY WILL BE OVER SAN
BERNARDINO COUNTY DUE TO THE MOISTURE PROFILE THERE. FRIDAY LOOKS
FAIRLY COOL DUE TO THE UPPER LOW BUT WILL INCREASE SOME OVER THE
WEEKEND...WITH MODERATELY HIGH HUMIDITY POSSIBLE DUE TO THE
CONTINUED HIGH SST VALUES.
&&
.AVIATION...
161519Z...MOSTLY UNRESTRICTED VIS THROUGH WEDNESDAY MORNING. CLOUDS
IN THE 5000-10000 FT MSL LAYER ALONG THE DESERT SLOPES AND PORTIONS
OF THE ADJACENT DESERTS WILL CONTINUE THROUGH 1800 UTC. 1800-17/0300
UTC TIME-FRAME...SCT-BKN CLOUDS AT OR ABOVE 8000 FT MSL WITH
ISOL-SCT THUNDERSTORMS/SHOWERS DEVELOPING OVER THE
MOUNTAINS...VALLEY...INCLUDING THE INLAND EMPIRE AND POSSIBLY OVER
PORTIONS OF THE DESERTS. THUNDERSTORMS MAY PRODUCE SMALL
HAIL...GUSTY/ERRATIC WINDS AND LOWERED VIS DUE TO HEAVY RAIN. CB TOPS
35000-45000 FT MSL POSSIBLE. ALSO...E WIND GUSTS 25-35 KT ALONG MTN
RIDGES...COASTAL SLOPES AND INTO THE VALLEYS WILL RESULT IN MODERATE
UP/DOWNDRAFTS AND POSSIBLE LLWS THROUGH 17/0000 UTC.
&&
.MARINE...
819 AM...NO HAZARDOUS MARINE WEATHER EXPECTED THROUGH SUNDAY.
&&
.BEACHES...
AT 8 AM...THE SAN CLEMENTE BASIN BUOY SHOWED A SOUTHWEST SWELL AT
AROUND 4 FEET/19-21 SECONDS...AND THE NEARSHORE BUOYS SHOWED A
SOUTH-SOUTHWEST SWELL AT 3 FEET/20 SECONDS. THIS IS LARGER THAN
WHAT THE WAVE WATCH 3 FORECAST OF ONLY 2 FEET SHOWED. CONSIDERING
THIS...ELEVATED SURF OF 4-6 FEET ALONG SOUTHWEST FACING BEACHES AND
WIDESPREAD STRONG RIP AND LONGSHORE CURRENTS IS LIKELY THROUGH
THURSDAY. THUS...A BEACH HAZARDS STATEMENT HAS BEEN ISSUED...EFFECTIVE
THIS MORNING THROUGH EARLY THURSDAY EVENING. THE SOUTH-SOUTHWEST SWELL
WILL SLOWLY LOWER FRIDAY INTO THE WEEKEND...DIMINISHING THE SURF AND
RIP CURRENT THREAT.
&&
.SKYWARN...
SKYWARN ACTIVATION MAY BE REQUESTED THIS AFTERNOON DUE TO POSSIBLE
THUNDERSTORMS OVER THE VALLEYS...MOUNTAINS AND DESERTS. ACTIVATION
IS AGAIN POSSIBLE WEDNESDAY AFTERNOON IN THE SAME AREAS. WEATHER
SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS TO
THE NATIONAL WEATHER SERVICE AS SOON AS IS SAFELY POSSIBLE.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HEAT ADVISORY UNTIL 7 PM PDT THIS EVENING FOR THE ORANGE COUNTY
COASTAL AREAS...SAN BERNARDINO AND RIVERSIDE COUNTY
VALLEYS-THE INLAND EMPIRE...SAN DIEGO COUNTY COASTAL
AREAS...SAN DIEGO COUNTY VALLEYS...SANTA ANA MOUNTAINS AND
FOOTHILLS.
BEACH HAZARDS STATEMENT THROUGH THURSDAY EVENING FOR THE BEACHES
IN THE ORANGE COUNTY COASTAL AREAS...SAN DIEGO COUNTY
COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...MAXWELL
AVIATION/MARINE/BEACHES...HARRISON
AREA FORECAST DISCUSSION
NWS POCATELLO ID
155 PM MDT TUE SEP 16 2014
.SHORT TERM...TONIGHT THROUGH FRIDAY. SATELLITE IMAGERY WAS SHOWING
A BROAD LOW PRESSURE CENTER SPINNING OFF THE NRN CALIFORNIA COAST
EARLY THIS AFTERNOON WITH A DOWNSTREAM RIDGE POSITIONED OVER ERN
IDAHO. MUCH FURTHER SOUTH...THE REMNANTS OF HURRICANE ODILE WERE
VISIBLE ROTATING NE ACROSS THE GULF OF CALIFORNIA...EAST OF THE
PREVIOUS FORECAST TRACK. THE GFS/NAM WERE BOTH SHOWING ISOLATED
CONVECTION DEVELOPING ACROSS THE REGION THIS AFTERNOON AS WEAK
DISTURBANCES EJECT FROM THE LOW OFF THE COAST AND ROTATE THROUGH THE
RIDGE. A FEW CELLS MAY PREVAIL THROUGH THE NIGHT...BUT BOTH MODELS
WERE MUCH LESS ENTHUSED ABOUT THE POTENTIAL FOR CONVECTIVE ACTIVITY
COMPARED TO YESTERDAYS MODEL RUNS. THE RIDGE IS EXPECTED TO AMPLIFY
SOME AND SHIFT EAST INTO THE DIVIDE WEDNESDAY. ONE WOULD EXPECT AN
INCREASING POTENTIAL FOR CONVECTIVE ACTIVITY...BUT BOTH THE GFS AND
NAM WERE SHOWING JUST ISOLATED ILL ORGANIZED CONVECTIVE ACTIVITY IN
THE ABSENCE OF ANY WELL DEFINED DYNAMICAL SUPPORT. THE MODELS SHOW
THE UPPER TROUGH SHIFTING INTO THE COAST THURSDAY MORNING WITH THE
ASSOCIATED UPPER JET LIFTING NE THROUGH ERN OREGON/NORTH IDAHO WITH
ENOUGH LIFT TO SUPPORT A BROAD BAND OF CONVECTION ACROSS SOUTH-CNTRL
IDAHO WHICH EXPANDS EWRD DURING THE DAY AS THE UPPER TROUGH
CONTINUES TO PUSH INLAND. THE DEVELOPMENT OF A SURFACE FRONT WHICH
ADVANCES INTO/THROUGH SE IDAHO SHOULD ALSO HELP TO PROMOTE ACTIVE
CONVECTION THROUGHOUT THE DAY. IT STILL REMAINS UNCERTAIN AS TO
WHETHER ANY MOISTURE FROM ODILE WILL BE SWEPT NORTHWARD IN THE DEEP
SOUTHERLY FETCH AHEAD OF THE TROUGH. THE NAM APPEARS TO SUPPORT THIS
IDEA WHILE THE GFS KEEPS THE MOISTURE WELL TO THE SOUTH. WITH THE
REMNANTS OF ODILE TRACKING FURTHER EAST OF PREVIOUS PROGS...I AM
LEANING IN THE DIRECTION OF THE GFS SOLUTION. AS THE UPPER TROUGH
PROGRESSES FURTHER INLAND THURSDAY NIGHT...A DEFINITIVE SPLIT OCCURS
WITH THE NRN BRANCH OF THE TROUGH PUSHING FAIRLY RAPIDLY EAST ALONG
THE CANADIAN HIGH-LINE WHILE THE SRN EXTENT OF THE TROUGH SPINS OFF
A CLOSED LOW OVER NRN CALIFORNIA (A BIT FURTHER NORTH THAN
YESTERDAYS PROGS). THE NORTHERLY PLACEMENT OF THE CUT-OFF LOW
COMBINED WITH THE SURFACE FRONTAL BOUNDARY POSITIONED JUST TO OUR
SOUTH HAVE RESULTED IN A BROAD AREA OF PRECIPITATION DEVELOPING IN
THE MODELS AND EXTENDING FROM NE NEVADA ACROSS THE SE HIGHLANDS
THURSDAY NIGHT. HAVE GENERALLY BOOSTED THE PRECIPITATION POTENTIAL
DURING THIS TIME FRAME BUT WITH LOW CONFIDENCE DUE TO RUN TO RUN
MODEL INCONSISTENCIES. BY FRIDAY...THE TAIL END OF THE NRN BRANCH
TROUGH SWEEPS THROUGH THE AREA WITH A DRIER NW FLOW OVERSPREADING
THE REGION. HUSTON
.LONG TERM...FRIDAY NIGHT THROUGH NEXT TUESDAY. AS WAS THE CASE
YESTERDAY...THE MODELS CONTINUE TO STRUGGLE WITH THE POSITION AND
TRACK OF THE CUT-OFF LOW FLOUNDERING OVER CALIFORNIA EARLY IN THE
PERIOD. THE LATEST 12Z GFS LIFTS THE LOW ENE ACROSS NEVADA SUNDAY
AND NRN UTAH SUNDAY NIGHT WITH ACCOMPANYING PRECIPITATION CLIPPING
THE FAR SE HIGHLANDS LATE SUNDAY NIGHT/MONDAY FOLLOWED BY A RETURN
TO DRY CONDITIONS AS THE RIDGE REBOUNDS ACROSS THE AREA. THE ECMWF
ON THE OTHER HAND...RETROGRADES THE LOW OFF THE COAST SUNDAY WHERE
IT REMAINS UNTIL BEING SWEPT INLAND ACROSS CALIFORNIA MONDAY AND
INTO NRN NEVADA TUESDAY. WITH POOR MODEL CONSISTENCY...HAVE
GENERALLY MAINTAINED THE GOING FORECAST WHICH FAVORS THE GFS
TIMING/TRACK. WILL AWAIT BETTER CONSENSUS IN THE MODELS BEFORE
TRYING TO NAIL DOWN ANY CHANGES IN THIS TIME FRAME. HUSTON
&&
.AVIATION...A WEAK SHORTWAVE PUSHING THROUGH UPPER RIDGE IS HELPING
TRIGGER SOME SHOWERS OVER THE REGION. INSTABILITY CONTINUING THROUGH
THIS AFTERNOON MAY KEEP SHOWERS MORE ACTIVE FOR PIH AND IDA...BUT
LOOKS LIKE THIS WILL BE MAINLY FOCUSED OVER THE MOUNTAINS. LOCAL WRF
AND HRRR MODELS INFLUENCED FORECAST AS THEY SUGGEST EARLIER END OF
PRECIP OVER IDA VERSUS THE 12Z NAM. ALL SITES SHOULD REMAIN VFR
THROUGH PERIOD. HINSBERGER
&&
.FIRE WEATHER...SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE
MAINLY OVER THE CENTRAL AND EASTERN MOUNTAINS THROUGH THIS EVENING.
EXPECT RE-DEVELOPMENT OF THUNDERSTORMS AGAIN WEDNESDAY AFTERNOON AS
A DEEP UPPER TROUGH CHANNELS MORE MOISTURE INTO SOUTHEAST IDAHO.
MOISTURE TRANSPORT PEAKS ON THURSDAY AS THE UPPER TROUGH AND SURFACE
COLD FRONT PUSH INTO THE REGION. THIS WILL MEAN INCREASED
THUNDERSTORM COVERAGE FOR THURSDAY AFTERNOON. STORMS WILL BRING
LOCALLY HEAVY RAINFALL WITH THE FOCUS BEING OVER THE SOUTHEASTERN
HIGHLANDS. DRIER WEATHER IS EXPECTED BY FRIDAY AFTERNOON AND SHOULD
LAST THROUGH THE WEEKEND. HINSBERGER
&&
.PIH WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
200 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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1132 AM MDT TUE SEP 16 2014
SKIES HAVE GRADUALLY CLEARED THIS MORNING AS STRATUS ERODES FROM
WEST TO EAST. STRATUS SHOULD CLEAR KMCK OVER THE NEXT HOUR. SOUTH
WINDS WEAKEN THIS AFTERNOON AS A LEE TROUGH MOVES THROUGH...
BECOMING LIGHT AND VARIABLE TONIGHT. HIGH RESOLUTION MODELS
INDICATE THAT UNDER CLEAR SKIES AND LIGHT WINDS...FOG SHOULD
BECOME A PROBLEM WHERE MOISTURE POOLS EAST OF THE LEE TROUGH.
THIS CONFINES FOG THREAT TO KMCK TONIGHT. HIGH-RES MODELS SUGGEST
FOG COULD BE DENSE. LOWERED VIS AT KMCK TO IFR. CONDITIONS IMPROVE
BY LATE MORNING AS FOG/STRATUS ERODES FROM WEST TO EAST ONCE AGAIN.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...99
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
147 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 THROUGH MONDAY)
ISSUED AT 243 AM MDT TUE SEP 16 2014
MAIN WEATHER FEATURE FOR WEDNESDAY ON INTO THURSDAY NIGHT WILL
CONTINUE TO BE THE ABOVE NORMAL WARMER TEMPERATURES BROUGHT ABOUT
BY SFC RIDGE TO OUR EAST. SOUTHERLY FETCH DURING THIS TIME FRAME
WILL BRING TEMPS DURING THE DAY INTO THE MID 80S TO AROUND
90F...ESPECIALLY ON THURSDAY. WED NIGHT INTO THURSDAY MORNING HAS
MODELS DO SHOWING A WEAK 925/850 MB TROUGH STRETCHING OUT FROM THE
EASTERN SIDE OF THE ROCKIES AND INTO THE CWA. THIS ALONG WITH SE
FLOW AHEAD OF IT FROM RIDGE POSITION...LOOKS TO BRING IN A SL
CHANCE FOR RW/TRW WITH ONLY EASTERN ZONES TO BE AFFECTED. LOW
LEVEL INVERSION STILL HAS CHANCE TO BRING ABOUT AREAS OF FOG IN
MANY LOCALES FOR THE OVERNIGHT PERIODS...WITH OVERNIGHT LOWS WILL
RANGE IN THE 50S TO LOW 60S WED NIGHT TO WELL INTO THE 60S FOR
THURSDAY NIGHT...AS WIND REGIME FROM THE SE WILL TAP INTO THE
MORE HUMID GULF MOISTURE.
AN UPPER LEVEL RIDGE WILL BEGIN TO BREAK DOWN ACROSS THE CENTRAL
PLAINS AS A SHORTWAVE TROUGH BEGINS TO MOVE INTO THE FORECAST AREA
ON FRIDAY. HIGH TEMPERATURES WILL REACH THE MID 80S BEFORE COOLER
AIR MOVES INTO THE CENTRAL PLAINS WITH THE PASSAGE OF A COLD FRONT.
AS WITH PAST MODEL RUNS...THERE CONTINUES TO BE SOME SLIGHT
DIFFERENCES AS TO THE PROGRESSION AND TIMING OF THE UPPER LEVEL
SYSTEM INTO THE HIGH PLAINS. WITH SURFACE FRONTAL FORCING AND SOME
INSTABILITY ALOFT...THERE WILL BE INCREASED CHANCES FOR SHOWERS AND
A FEW RUMBLES OF THUNDER FRIDAY EVENING INTO SATURDAY ACROSS THE
REGION. ONCE THE SURFACE FRONT PASSES THROUGH THE AREA SATURDAY
MORNING...SLIGHTLY COOLER TEMPERATURES WILL FILTER INTO THE REGION
WITH HIGHS OVER THE WEEKEND REACHING THE UPPER 70S TO LOWER 80S. AN
UPPER LEVEL RIDGE WILL BUILD TO THE WEST...WHICH WILL BRING DRY
CONDITIONS ACROSS THE REGION FOR SUNDAY AND INTO THE BEGINNING OF
NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1132 AM MDT TUE SEP 16 2014
SKIES HAVE GRADUALLY CLEARED THIS MORNING AS STRATUS ERODES FROM
WEST TO EAST. STRATUS SHOULD CLEAR KMCK OVER THE NEXT HOUR. SOUTH
WINDS WEAKEN THIS AFTERNOON AS A LEE TROUGH MOVES THROUGH...
BECOMING LIGHT AND VARIABLE TONIGHT. HIGH RESOLUTION MODELS
INDICATE THAT UNDER CLEAR SKIES AND LIGHT WINDS...FOG SHOULD
BECOME A PROBLEM WHERE MOISTURE POOLS EAST OF THE LEE TROUGH.
THIS CONFINES FOG THREAT TO KMCK TONIGHT. HIGH-RES MODELS SUGGEST
FOG COULD BE DENSE. LOWERED VIS AT KMCK TO IFR. CONDITIONS IMPROVE
BY LATE MORNING AS FOG/STRATUS ERODES FROM WEST TO EAST ONCE AGAIN.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...JN/MK
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1252 PM CDT TUE SEP 16 2014
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 114 AM CDT TUE SEP 16 2014
THIS MORNING WILL BE PLAGUED BY WIDESPREAD FOG AND LOW CEILINGS.
THERE IS ABUNDANT MOISTURE AT THE LOWER LAYERS AND THE LIGHT WINDS
WILL ALLOW THE TEMP/DEWPOINT DEPRESSION TO WITHER TO 1 TO 2 DEGREES
APART. THIS FOG SHOULD START IN OUR NORTHWEST ZONES FIRST NEAR
SYRACUSE AND SCOTT CITY, AND SPREAD SOUTHEASTWARD BETWEEN 09Z AND
12Z. FOR NOW, I ONLY EXPECT VISIBILITIES TO BE REDUCED TO LESS THAN
1 MILE, SO A FOG ADVISORY DOES NOT SEEM WARRANTED, BUT SHOULD BE
WATCHED AND MONITORED. THIS FOG AND THE LOW CLOUDS WILL DELAY THE
DAY TIME HEATING, BUT THE WARM ADVECTION WILL WIN OUT LATER THIS
MORNING. THE WARMEST TEMPERATURES WILL BE NEAR THE COLORADO
BORDER, WHERE A LEE SIDE TROUGH WILL EXIST. MID 80S SHOULD BE
REALIZED THERE, WHILE COOLER HIGH PRESSURE TO OUR EAST WILL RESULT
IN HIGH TEMPERATURES IN THE MID 70S NEAR HAYS AND LACROSSE. THE
CLOUDS WILL LINGER OVER OUR EASTERN ZONES THROUGH MUCH OF THE
AFTERNOON. LIGHT AND VARIABLE WINDS EARLY TODAY WILL BECOME FROM
THE SOUTH AT ONLY THE 10 TO 12 MPH RANGE THIS AFTERNOON. I HAVE
CHOSE TO FOLLOW THE HRRR AND RUC MODELS, WHICH KEEP ANY PRECIPITATION
TODAY TO OUR SOUTH. OF NOTE HOWEVER, ARE BOTH THE HIRESW-NMM AND
THE HIRESW-ARW MODELS WHICH BOTH BRING LIGHT PRECIPITATION TO OUR
SOUTHERN CWA THIS AFTERNOON, BASICALLY SOUTH OF HIGHWAY 50.
I EXPECT NEARLY CLOUD-FREE SKIES OVERNIGHT WITH LIGHT SOUTH WINDS AT
6 TO 8 MPH. THE TEMP/DEWPOINT SPREAD IS EXPECTED TO BE GREATER
TONIGHT, SO I DON`T EXPECT AS MUCH FOG OR STRATUS. THERE COULD BE
SOME 3 TO 5SM FOG, ESPECIALLY IN OUR EAST, BUT I DON`T THINK THIS
IS WORTH MENTIONING. MINIMUM TEMPERATURES SHOULD BE SIMILAR TO
THIS MORNING, RANGING FORM THE LOWER 60S NORTH OF I-70 TO THE MID
60S IN THE BARBER AND COMANCHE COUNTY AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 322 AM CDT TUE SEP 16 2014
MEDIUM RANGE MODELS INDICATE A NORTHWESTERLY FLOW ALOFT PREVAILING
ACROSS THE WESTERN HIGH PLAINS WEDNESDAY AS UPPER LEVEL RIDGING
SLOWLY EDGES EASTWARD ACROSS THE INTERMOUNTAIN WEST INTO THE WESTERN
HIGH PLAINS. THIS WILL LEND TO DRIER CONDITIONS ACROSS MUCH OF
WESTERN KANSAS EARLY IN THE PERIOD. HOWEVER, ISOLATED THUNDERSTORMS
CANNOT BE RULED OUT ACROSS PORTIONS OF CENTRAL AND SOUTH CENTRAL
KANSAS WEDNESDAY NIGHT AS A SURFACE LOW BECOMES MORE ORGANIZED
ACROSS WESTERN KANSAS. A NEAR STATIONARY FRONTAL BOUNDARY IS
PROJECTED TO EXTEND EAST-SOUTHEAST OFF THE SURFACE LOW ACROSS
SOUTHERN KANSAS PROVIDING INCREASED CONVERGENCE. ALONG WITH A
STRONGER FLOW ALOFT, STEEPENING LOW/MID LEVEL LAPSE RATES AND
INCREASED INSTABILITY MAY BE ENOUGH TO SUPPORT THUNDERSTORM
DEVELOPMENT IN THE VICINITY OF THE BOUNDARY WEDNESDAY EVENING INTO
EARLY THURSDAY MORNING. OTHERWISE, DRIER CONDITIONS WILL PREVAIL
ACROSS WESTERN KANSAS THROUGH THURSDAY NIGHT AS THE UPPER LEVEL
RIDGE TRANSITIONS ACROSS THE WESTERN HIGH PLAINS INTO THE CENTRAL
PLAINS.
MORE WIDESPREAD RAINFALL WILL BE POSSIBLE ACROSS WESTERN AND
CENTRAL KANSAS LATE FRIDAY INTO SATURDAY AS THE REMNANTS OF
TROPICAL STORM ODILE ARE PROJECTED TO LIFT NORTHEAST ACROSS THE
DESERT SOUTHWEST THURSDAY ON THE BACKSIDE OF THE UPPER LEVEL RIDGE
SHIFTING EASTWARD INTO THE CENTRAL PLAINS. THE REMNANTS WILL LIFT
FURTHER NORTHEAST INTO THE HIGH PLAINS OF EXTREME EASTERN COLORADO
AND WESTERN KANSAS FRIDAY. MEANWHILE, AN UPPER LEVEL SHORTWAVE
TROUGH IS EXPECTED TO SWING EASTWARD ACROSS THE NORTHERN PLAINS
FRIDAY NIGHT INTO SATURDAY SENDING AN ATTENDANT COLD FRONT SURGING
SOUTHEASTWARD INTO WESTERN AND CENTRAL KANSAS WHILE ADDITIONAL
MOISTURE POOLS AHEAD OF THE APPROACHING FRONT WITHIN A
SOUTHEASTERLY UPSLOPE FLOW. AS A RESULT, SHOWERS AND ISOLATED
THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
WITH THE ONSET OF PRECIP TOWARD FRIDAY AFTERNOON/EVENING. SHOWERS
AND ISOLATED THUNDERSTORMS ARE EXPECTED TO SPREAD EASTWARD INTO
CENTRAL KANSAS LATE FRIDAY NIGHT INTO SATURDAY. BASED ON PW
VALUES AND QPF FIELDS, SOME AREAS COULD SEE IN EXCESS OF ONE HALF
INCH OF RAINFALL BY EARLY SATURDAY MORNING WITH HIGHER AMOUNTS
FURTHER TO THE EAST WHERE INCREASED MOISTURE WILL BE MORE READILY
AVAILABLE.
ABOVE NORMAL TEMPERATURES ARE LIKELY WEDNESDAY AS A SURFACE LOW
DEEPENS ACROSS THE HIGH PLAINS ENHANCING AN ALREADY PREVAILING
SOUTHERLY FLOW INTO WESTERN KANSAS. THE GFS/ECMWF ARE IN FAIR
AGREEMENT SHOWING H85 TEMPERATURES CLIMBING A LITTLE ABOVE 20C
ACROSS CENTRAL KANSAS TO NEAR 25C CLOSER TO THE COLORADO BORDER IN
SOUTHWEST KANSAS. WITH MODEL SOUNDINGS INDICATING STEEP LOW LEVEL
LAPSE RATES BY WEDNESDAY AFTERNOON, LOOK FOR HIGHS WELL UP INTO
THE 80S(F) WITH NEAR 90F IN SOME LOCATIONS. WARM AIR ADVECTION
WILL CONTINUE THURSDAY AS THE SOUTHERLY FLOW PERSISTS RAISING
HIGHS A FEW DEGREES WITH A FEW MORE LOWER 90S(F) POSSIBLE.
SLIGHTLY LOWER HIGH TEMPERATURES CAN BE EXPECTED FRIDAY AS CLOUD
COVER BECOMES MORE WIDESPREAD WITH AREAS OF PRECIP POSSIBLE AS
EARLY AS FRIDAY AFTERNOON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1247 PM CDT TUE SEP 16 2014
LOW STRATUS HAS SCATTERED OUT WITH VFR CONDITIONS EXPECTED TO
PREVAIL THE REMAINDER OF THE AFTERNOON AND MUCH OF THE NIGHT.
WINDS WILL BE OUT OF THE SOUTH 10 TO 15 KNOTS WITH A LEE TROUGH
CONTINUING TO SLOWLY DEEPEN ACROSS EASTERN COLORADO. LIGHT SOUTH
WINDS IN THE 08-14Z TIME FRAME AROUND 6 TO 8 KNOTS, COMBINED WITH
TEMPERATURES FALLING TO THE LOWER 60S, WILL LEAD TO SOME LIGHT FOG
POTENTIAL AT GCK, DDC, AND HYS. THE BEST CHANCE FOR LOWEST
VISIBILITY WILL BE AT HYS AND AROUND DAYBREAK, HOWEVER CONFIDENCE
IS LOW AND WILL NOT YET FORECAST IFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 81 64 89 63 / 10 10 0 10
GCK 83 61 89 62 / 10 0 0 10
EHA 84 62 89 62 / 10 0 0 10
LBL 84 63 90 64 / 10 0 0 10
HYS 75 61 84 63 / 10 10 0 20
P28 80 66 89 63 / 10 10 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...JJOHNSON
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
350 PM EDT TUE SEP 16 2014
.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.
&&
$$
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 118 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU TONIGHT AS
LOW LEVELS REMAIN DRY. COLD FRONT CURRENTLY OVER NRN 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...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
334 PM EDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE SEP 16 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE AND ASSOC JET
MAX MOVING THROUGH NRN ONTARIO WHICH HAS SUPPORTED A CLUSTER OF SHRA
ALONG COLD FRONTAL BOUNDARY OVER NW ONTARIO AS NOTED ON CANADIAN
RADAR MOSIAC. CLEAR SKIES AND LIGHT WINDS UNDER SFC HIGH PRES RIDGE
HAVE ALLOWED FOR MIN TEMPS TO DROP NEAR OR BLO THE FREEZING MARK FOR
MANY OF THE TYPICAL INTERIOR COLD SPOT LOCATIONS ACROSS UPPER MI
EARLY THIS MORNING.
TODAY...PLENTY OF SUNSHINE THIS MORNING WILL GIVE WAY TO INCREASING
CLOUDS LATE IN THE AFTERNOON AS A COLD FRONT SAGS SOUTHWARD THROUGH
LAKE SUPERIOR. MODELS INDICATE THAT ANY LIGHT PCPN ASSOCIATED WITH
THE FRONT AND ASSOC 900-800 MB FGEN SHOULD STAY NORTH OF THE
KEWEENAW UNTIL EVENING. OTHERWISE...EXPECT TEMPERATURES TO REBOUND
CLOSER TO SEASONAL AVERAGES WITH HIGHS IN THE MID 60S AND PERHAPS
EVEN REACHING UPPER 60S FOR A FEW DOWNSLOPING LOCATIONS OVER NCNTRL
UPPER MI IN DEVELOPING WSW FLOW AHEAD OF THE FRONT.
TONIGHT...THE COLD FRONT WILL SAG SOUTH INTO MAINLY THE NW AND ERN
CWA BY LATE EVENING. MODELS SHOW THAT THE BEST MOISTURE WILL BE N OF
THE FRONT WITH THE BEST FORCING/Q-VECT CONV TO BE OVER NW AND ERN
CWA LATE TONIGHT AHEAD OF A SHORTWAVE MOVING ACROSS WRN ONTARIO AND
IN THE RIGHT ENTRANCE REGION OF ASSOC 100+ KT 3H JET MAX MOVING INTO
WRN QUEBEC. WILL MAINTAIN SLIGHT CHC TO LOW CHC POPS FOR SHRA OVER
MAINLY THE KEWEENAW AND FAR NE CWA.
.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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 118 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU TONIGHT AS
LOW LEVELS REMAIN DRY. COLD FRONT CURRENTLY OVER NRN 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 455 AM EDT TUE SEP 16 2014
EXPECT WSW WINDS TO 25 KTS THROUGH EARLY AFTERNOON AHEAD OF A COLD
FRONT APPROACHING FROM ONTARIO. WINDS WILL DIMINISH AS FRONT MOVES
OVERHEAD TONIGHT BUT THEN INCREASE TO UP TO 25 KTS FROM THE
NORTHEAST IN THE WAKE OF THE COLD FRONT ON WEDNESDAY...MAINLY OVER
WRN LAKE SUPERIOR. 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. WINDS
WILL LIKELY DIMINISH ON SATURDAY AS LOW PRES TROUGH FROM THE PLAINS
MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
200 PM EDT TUE SEP 16 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 319 AM EDT TUE SEP 16 2014
AN AREA OF HIGH PRESSURE WILL BUILD INTO THE REGION TODAY FROM THE
WEST. THIS SYSTEM WILL HELP TO CREATE AREAS OF DENSE FOG THIS
MORNING. THE FOG WILL DISSIPATE LATER THIS MORNING GIVING WAY TO
MOSTLY SUNNY SKIES AND BELOW NORMAL TEMPERATURES. A WEAK COLD
FRONT WILL SLIP SOUTH OF THE REGION WEDNESDAY NIGHT. THEN A VERY
STRONG HIGH PRESSURE SYSTEM WILL BUILD DOWN FROM THE NORTH FOR THE
END OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 319 AM EDT TUE SEP 16 2014
THE MAIN CHALLENGE DEALS WITH THE POTENTIAL FOR DENSE FOG EARLY
THIS MORNING. OVERALL IT LOOKS LIKE MOST LOCATIONS WILL SEE DENSE
FOG THIS MORNING. AS A RESULT I ISSUED A DENSE FOG ADVISORY.
THICK FOG ALREADY EXISTS IN PLACES...ESPECIALLY NORTH OF
INTERSTATE 96 AS OF 3 AM. HRRR RUC SHOWS THE SKIES TEMPORARILY
CLEARING OUT ACROSS SOUTHERN LOWER MI WITH THE THICK FOG BUILDING
SOUTHWARD THROUGH THE REMAINDER OF THE NIGHT. THE FOG IS SHOWN TO
SLOWLY DISSIPATE LATE THIS MORNING. AS A RESULT WITH AN ELEVATED
RISK FOR HAZARDOUS CONDITIONS FOR THE MORNING COMMUTE AND AT BUS
STOPS...I DECIDED THAT AN ADVISORY WOULD BE THE BEST WAY TO GO.
THE REMAINDER OF THE FORECAST IS RELATIVELY QUITE WITH A WEAK DRY
COLD FRONTAL PASSAGE WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 319 AM EDT TUE SEP 16 2014
THE MAIN FOCUS OF THE LONG TERM PORTION OF THE FCST CONTINUES TO BE
THE SYSTEM THAT IS FCST TO MOVE THROUGH THE AREA THIS WEEKEND AND
THE ASSOCIATED PCPN CHCS WITH IT.
WE SHOULD SEE ONE MORE DRY AND QUITE MILD DAY AT THE BEGINNING OF
THE PERIOD ON FRI. THE FAR NW CORNER COULD SEE A LOW CHC OF SOME
RAIN LATE ON FRI AFTERNOON. WE WILL SEE AN UPPER RIDGE IN THE
PROCESS OF WEAKENING AS IT MOVES EAST INTO THE AREA DURING THE DAY
ON FRI. THIS WILL KEEP MOST OF THE AREA DRY. INCREASING SRLY RETURN
FLOW WILL BRING A NICE SURGE OF WARMTH INTO THE AREA.
THE THREAT OF RAIN WILL GRADUALLY INCREASE STARTING FRI NIGHT AND
WILL PEAK ON SAT NIGHT. WE WILL SEE THE INITIAL SFC LOW WITH THE
NEXT FRONT STAY WELL NORTH INTO CANADA...TAKING WITH IT THE BEST LOW
LEVEL JET AND MOISTURE TRANSPORT WITH IT. THE FRONT WILL APPROACH
THE AREA LATE ON SAT AND THEN MOVE THROUGH THE AREA ON SAT NIGHT AND
INTO THE FIRST PART OF SUN. WE COULD SEE ANOTHER VERY MILD DAY ON
SAT IF WE SEE A DECENT AMOUNT OF SUNSHINE AND H850 TEMPS IN THE MID
TEENS C.
THE INTERESTING THING ABOUT THE FRONTAL PASSAGE WILL BE THAT SOME OF
THE MODELS ARE INDICATING THAT SOME REMNANTS FROM THE TROPICAL
SYSTEM ODILE COULD INTERACT WITH THE FRONT. THIS COULD LEAD TO A BIT
MORE RAIN THAN CURRENTLY FCST AS THE MODELS TYPICALLY UNDER FCST THE
AMOUNT OF HEAT AND MOISTURE WITH SYSTEMS OF A TROPICAL ORIGIN THAT
BECOME EXTRA-TROPICAL. THIS WILL BE SOMETHING TO WATCH.
WE SHOULD DRY OUT DURING THE SECOND HALF OF SUN AS WE SEE THE DRY
SLOT MOVE THROUGH THE AREA. WE COULD SEE ONE MORE MILD DAY ON SUN
BEFORE THE COLD CONVEYOR BELT WRAPS INTO THE AREA ON MON. THE MODELS
ARE SHOWING H850 TEMPS DROPPING DOWN CLOSE TO ZERO C ON MON. THERE
IS FAIRLY DECENT AGREEMENT WITH THE STRENGTH AND TIMING OF THIS LOW
AND THE COLD AIR BEHIND IT. WE HAVE ADDED SOME LAKE EFFECT RAIN
SHOWERS FOR MON ALONG THE SHORE WITH AN EXPECTED NNW WIND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 200 PM EDT TUE SEP 16 2014
VFR CONDITIONS EXPECTED NEXT 24 HOURS AND BEYOND. MOSITURE WHICH WAS
RESPONSIBLE FOR THE FOG THIS MORNING CONTINUES TO MIX OUT OF THE
LOWER LEVELS. EXPECT MUCH LESS FOG TONIGHT ALTHOUGH IT`S A GOOD BET
THERE WILL BE SOME SHALLOW RIVER / VALLEY FOG WITH CLEAR SKIES AND
LIGHT WINDS.
A WEAK COLD FRONT WILL BE THE FOCUS OF SOME VARIABLE SCT-BKN
CONDITIONS WEDNESDAY AFTN WITH BASES GENERALLY AT OR ABOVE 040KFT.
OUTLLOOK...IFR/MVFR CEILINGS POSSIBLE TOWARDS SATURDAY MORNING AS
MOISTRE FROM THE NEXT SYSTEM ARRIVES. THUNDERSTORMS POSSIBLE
SATURDAY NIGHT WITH NEXT COLD FRONTAL PASSAGE.
&&
.MARINE...
ISSUED AT 319 AM EDT TUE SEP 16 2014
MAY END UP WITH WAVES APPROACHING SMALL CRAFT ADVISORY CRITERIA
WEDNESDAY NIGHT INTO THURSDAY AROUND BIG SABLE POINT AS A STRONGER
NORTHEAST FLOW DEVELOPS. WILL CONTINUE TO MONITOR THIS POTENTIAL.
OTHERWISE THE MARINE FORECAST LOOKS QUIET AT THIS POINT.
&&
.HYDROLOGY...
ISSUED AT 319 AM EDT TUE SEP 16 2014
WILL NEED TO MONITOR THE HEAVY RAIN POTENTIAL OVER THE WEEKEND AS
A COLD FRONT MOVES THROUGH AND TAPS TROPICAL MOISTURE. OTHERWISE
NO MAJOR RAIN SYSTEMS EXPECTED THROUGH FRIDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...NJJ
AVIATION...COBB
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
119 PM EDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE SEP 16 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE AND ASSOC JET
MAX MOVING THROUGH NRN ONTARIO WHICH HAS SUPPORTED A CLUSTER OF SHRA
ALONG COLD FRONTAL BOUNDARY OVER NW ONTARIO AS NOTED ON CANADIAN
RADAR MOSIAC. CLEAR SKIES AND LIGHT WINDS UNDER SFC HIGH PRES RIDGE
HAVE ALLOWED FOR MIN TEMPS TO DROP NEAR OR BLO THE FREEZING MARK FOR
MANY OF THE TYPICAL INTERIOR COLD SPOT LOCATIONS ACROSS UPPER MI
EARLY THIS MORNING.
TODAY...PLENTY OF SUNSHINE THIS MORNING WILL GIVE WAY TO INCREASING
CLOUDS LATE IN THE AFTERNOON AS A COLD FRONT SAGS SOUTHWARD THROUGH
LAKE SUPERIOR. MODELS INDICATE THAT ANY LIGHT PCPN ASSOCIATED WITH
THE FRONT AND ASSOC 900-800 MB FGEN SHOULD STAY NORTH OF THE
KEWEENAW UNTIL EVENING. OTHERWISE...EXPECT TEMPERATURES TO REBOUND
CLOSER TO SEASONAL AVERAGES WITH HIGHS IN THE MID 60S AND PERHAPS
EVEN REACHING UPPER 60S FOR A FEW DOWNSLOPING LOCATIONS OVER NCNTRL
UPPER MI IN DEVELOPING WSW FLOW AHEAD OF THE FRONT.
TONIGHT...THE COLD FRONT WILL SAG SOUTH INTO MAINLY THE NW AND ERN
CWA BY LATE EVENING. MODELS SHOW THAT THE BEST MOISTURE WILL BE N OF
THE FRONT WITH THE BEST FORCING/Q-VECT CONV TO BE OVER NW AND ERN
CWA LATE TONIGHT AHEAD OF A SHORTWAVE MOVING ACROSS WRN ONTARIO AND
IN THE RIGHT ENTRANCE REGION OF ASSOC 100+ KT 3H JET MAX MOVING INTO
WRN QUEBEC. WILL MAINTAIN SLIGHT CHC TO LOW CHC POPS FOR SHRA OVER
MAINLY THE KEWEENAW AND FAR NE CWA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE SEP 16 2014
A COLD FRONT THAT MOVED INTO THE THE CWA TUE EVENING WILL HAVE A
WNW-ESE ORIENTATION OVER THE CENTRAL CWA AT 12Z WED...AND WILL MOVE
S OF THE CWA BY WED EVENING. BEST MOISTURE WILL BE N OF THE FRONT
AND BEST FORCING WILL BE OVER THE NRN CWA LATE TUE NIGHT INTO WED
MORNING AS AN UPPER TROUGH MOVES ACROSS THE AREA. A SFC HIGH WILL
MOVE IN QUICKLY BEHIND THE UPPER TROUGH/COLD FRONT...USHERING IN DRY
AND COLDER AIR. WHAT THIS MEANS FOR PRECIP CHANCES IS THAT THE
GREATEST POPS WILL BE OVER THE NRN CWA WED MORNING WITH THE UPPER
TROUGH ENERGY. PRECIP CHANCES ARE LOWER TO THE S...BUT SLIGHT CHANCE
TO LOW END CHANCE POPS WILL FOLLOW THE POST-FRONTAL MOISTURE S
THROUGH THE AFTERNOON. HIGH TEMPS WILL RANGE FROM AROUND 50 OVER NRN
UPPER MI NEAR LAKE SUPERIOR TO AROUND 60 OVER THE SCENTRAL.
THE SFC HIGH CENTER WILL MOVE ACROSS FAR NERN LAKE SUPERIOR WED
NIGHT INTO THU MORNING. PREVIOUS MODEL RUNS SHOWED A NARROW AREA OF
WAA AND GREATER MOISTURE OVER THE WRN CWA...BUT NEWEST RUNS SHOW
THAT BEING WELL SW OF THE CWA. THEREFOR...WHILE ERN UPPER MI SHOULD
STILL BE THE COLDEST DUE TO THE PROXIMITY TO THE HIGH AND COLDEST
AIRMASS...THE WRN CWA COULD ALSO SEE NEAR FREEZING TEMPS. LOOKS LIKE
FROST IS A GOOD POSSIBILITY ACROSS MUCH OF INLAND UPPER MI.
LOW LEVEL RETURN FLOW WILL BEGIN ON THU BETWEEN THE DEPARTING SFC
HIGH AND A BROAD TROUGH MOVING INTO THE WRN PLAINS. NO PRECIPITATION
IS EXPECTED THU DUE TO LINGERING DRY AIR. HIGH TEMPS WILL BE 1-2
DEGREES WARMER THAN WED.
WAA/ISENTROPIC ASCENT REALLY INCREASE LATE THU NIGHT AND FRI AS THE
SFC HIGH TO THE E SLOWS AND THE TROUGH TO THE W ACCELERATES
EASTWARD. THE WAA AND POSSIBLY SOME SHORTWAVE ENERGY WILL LIKELY
LEAD TO PRECIP ACROSS MUCH OF THE CWA FRI INTO FRI NIGHT. MODELS ARE
IN GOOD AGREEMENT THROUGH FRI...BUT BECOME MUCH HARDER TO USE FRI
NIGHT INTO SAT DUE /AT LEAST PARTLY/ TO WITH PHASING OF REMNANTS OF
HURRICANE ODILE WITH THE EXISTING TROUGH. WHILE MODELS DO ALL SHOW A
GOOD AMOUNT OF QPF FOR SAT...THEY DO NOT AGREE WELL IN THE FEATURES
CAUSING THE PRECIP. WHILE POPS WILL REMAIN HIGH ON SAT...SIGNIFICANT
UNCERTAINTY STILL EXISTS. WILL KEEP THUNDER CHANCES GOING FOR FRI
AFTERNOON THROUGH SAT EVENING...BUT AM NOT OVER CONCERNED ABOUT
HEAVY RAIN UNLESS REMNANTS OF ODILE END UP MOVING INTO THE AREA
/WHICH IS HIGH UNCERTAIN/. WARMEST CONDITIONS OF THE PERIOD ARE
EXPECTED ON SAT AS 850MB TEMPS INCREASE TO GREATER THAN 15C.
MUCH COLDER AIR MOVES IN WITH NW FLOW SUN AND MON...EVEN BRINGING
THE POSSIBILITY OF LAKE EFFECT RAIN SHOWERS BOTH DAYS. AGREE WITH
PREVIOUS SHIFT THAT ECMWF SHOULD BE SET ASIDE BECAUSE IT IS A COLD
OUTLIER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 118 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU TONIGHT AS
LOW LEVELS REMAIN DRY. COLD FRONT CURRENTLY OVER NRN 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 455 AM EDT TUE SEP 16 2014
EXPECT WSW WINDS TO 25 KTS THROUGH EARLY AFTERNOON AHEAD OF A COLD
FRONT APPROACHING FROM ONTARIO. WINDS WILL DIMINISH AS FRONT MOVES
OVERHEAD TONIGHT BUT THEN INCREASE TO UP TO 25 KTS FROM THE
NORTHEAST IN THE WAKE OF THE COLD FRONT ON WEDNESDAY...MAINLY OVER
WRN LAKE SUPERIOR. 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. WINDS
WILL LIKELY DIMINISH ON SATURDAY AS LOW PRES TROUGH FROM THE PLAINS
MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
ISSUED BY NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
1258 PM CDT TUE SEP 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM CDT TUE SEP 16 2014
THERE ARE PRIMARILY 3 MAIN ISSUES DURING THESE NEXT 24
HOURS...SOME OF WHICH MAY BE BIGGER DEALS THAN OTHERS.
THE FIRST INVOLVES WHETHER OR NOT A POTENTIALLY EXPANSIVE AREA OF
LOWER STRATUS CURRENTLY POSITIONED A FEW COUNTIES SOUTH-SOUTHWEST
OF THE CWA WILL SPREAD NORTHEAST OVER AT LEAST PARTS OF THE CWA
TODAY AND IF SO...HOW MUCH IMPACT TO HIGH TEMPS COULD OCCUR.
COMPARED TO 12-24 HOURS AGO...CONFIDENCE HAS WANED A BIT ON
WHETHER THESE CLOUDS REALLY WILL END UP AFFECTING MUCH OF THE AREA
AND FOR HOW LONG. ISSUE NUMBER 2 CONCERNS THUNDERSTORM CHANCES
TONIGHT...AS ALTHOUGH THE MAJORITY OF THE AREA CARRIES A PRETTY
GOOD CHANCE OF REMAINING STORM FREE...AT LEAST A SLIGHT CHANCE IS
REFLECTED FOR ROUGHLY THE SOUTHEAST 1/4 OF THE CWA POST-MIDNIGHT.
THIRDLY...ALTHOUGH MODELS/GUIDANCE ARE BY NO MEANS
UNANIMOUS...CONCERNS ARE INCREASING FOR AT LEAST SOME COVERAGE OF
POTENTIALLY IMPACTFUL FOG ISSUES LATE TONIGHT/EARLY WED MORNING
ESPECIALLY WITHIN THE WESTERN HALF OF THE CWA AS BREEZES AVERAGE
LIGHT AND SURFACE DEWPOINTS RISE 10+ DEGREES ABOVE CURRENTLY
OBSERVED VALUES...INDICATIVE OF INCREASING LOW LEVEL MOISTURE.
STARTING OFF WITH THE HERE AND NOW AS OF 08Z/3AM...A VERY QUIET
NIGHT CONTINUES ACROSS THE CWA UNDER NEARLY CLOUD-FREE SKIES. AT
THE SURFACE...A ROUGHLY 1025 MILLIBAR RIDGE AXIS IS CENTERED
SQUARELY OVER THE NEB/IA BORDER AREA...PROVIDING NEAR-CALM TO
LIGHT SOUTHEASTERLY BREEZES OF GENERALLY 6 MPH OR LESS. GIVEN THE
FAIRLY IDEAL RADIATIONAL COOLING CONDITIONS...TEMPS HAVE DROPPED
SOMEWHERE INTO THE 40S ACROSS MOST OF THE CWA AS EXPECTED...WITH
EVEN A FEW SITES VERY NEAR THE CWA SUCH AS COLUMBUS/BROKEN BOW AT
LEAST BRIEFLY INTO THE UPPER 30S. AUTOMATED AIRPORT SITES SUGGEST
THAT SOME VERY PATCHY...PRIMARILY LIGHT FOG LIKELY EXISTS OUT
THERE IN A FEW SPOTS...BUT BARRING NOTICEABLE CHANGES ITS
COVERAGE/IMPACT DOES NOT APPEAR WORTHY OF A FORMAL FORECAST
MENTION...WITH SOMEWHAT BETTER CHANCES OF A FEW DECENT VISIBILITY
REDUCTIONS POSSIBLY FOCUSING CLOSER TO THE NEB/IA BORDER. LOOKING
ALOFT TO THE MID-UPPER LEVELS...SHORT TERM MODEL DATA AND WATER
VAPOR IMAGERY INDICATES FAIRLY UNEVENTFUL AND BROAD NORTHWESTERLY
FLOW ALOFT OVER THE CENTRAL PLAINS...STEERED BETWEEN A LARGE SCALE
TROUGH OVER EASTERN CANADA AND A RIDGE EXTENDING NORTHWARD OVER
THE WESTERN CONUS. WAY OFF TO THE SOUTHWEST...TROPICAL STORM ODILE
SLOWLY CHURNS NORTHWEST UP THE BAJA PENINSULA.
LOOKING AHEAD AND STARTING WITH THE VERY SHORT TERM THROUGH
ROUGHLY SUNRISE...THE SURFACE RIDGE AXIS WILL CONTINUE A VERY SLOW
EASTWARD DEPARTURE...ALLOWING LIGHT SOUTH WINDS TO BECOME A BIT
BETTER ESTABLISHED ACROSS MUCH OF THE CWA. AS MENTIONED
ABOVE...THE BIGGEST SHORT TERM MYSTERY INVOLVES THE FATE OF THE
NORTHWEST KS STRATUS DECK...AS LAST FEW 11-3.9 MICRON SATELLITE
FRAMES SHOW ITS LEADING EDGES STARTING TO MAKE A PUSH TOWARD THE
SOUTHWESTERN FRINGES OF THE CWA...BUT UNLIKELY TO POTENTIALLY
INFILTRATE MUCH OF THE LOCAL AREA BEFORE SUNRISE. ALTHOUGH A FEW
PLACES MAY START STEADYING OUT A BIT ON THE TEMP-FALL...MOST OF
THE CWA IS ON TRACK TO REALIZE OVERNIGHT LOWS BETWEEN 41-46
DEGREES.
FOR THE DAYTIME HOURS 12Z-00Z/7AM-7PM...THE FORECAST REMAINS DRY
AS AM NOT EXPECTING THE VERY HIGH BASED WESTERN NEB SPRINKLES
CURRENTLY NOTED ON RADAR TO HAVE ANY IMPACT LOCALLY. THE MID-
UPPER LEVEL PICTURE REMAINS FAIRLY STEADY-STATE UNDER A BAND OF
MODESTLY STRONG NORTHWESTERLY FLOW...AS A RATHER SUBTLE LOW-
AMPLITUDE DISTURBANCE GRADUALLY APPROACHES THE LOCAL AREA FROM THE
NORTHWEST. AT THE SURFACE...THE COMBINATION OF A TIGHTENING
PRESSURE GRADIENT BETWEEN THE DEPARTING RIDGE AND MODEST HIGH
PLAINS PRESSURE FALLS TO THE WEST...ALONG WITH MIXING UP INTO A
WEAK-MODEST LOW LEVEL JET WILL PROMOTE INCREASING SOUTHERLY
BREEZES...ESPECIALLY DURING THE MID-MORNING TO MID-AFTERNOON
HOURS...WITH SUSTAINED SPEEDS GENERALLY 10-15 MPH AND GUSTS TO
AROUND 20 MPH ESPECIALLY WITHIN THE WESTERN 1/2 OF THE CWA. NOT TO
KEEP BEATING THE DRUM ON THIS ISSUE...BUT THE UNCERTAINTY IN THE
PRESENCE OR LACK THEREOF OF THE POTENTIAL INVADING STRATUS DECK
CERTAINLY RAISES SOME CONSIDERABLE QUESTIONS ON SKY COVER AND
RESULTANT TEMPS...WITH LIKELY AROUND A 5-DEGREE TEMP BUST
POTENTIAL ON THE LINE. BASED ON THE LATEST 06Z NAM 850 MILLIBAR
RELATIVE HUMIDITY PROGS...AT LEAST A LIMITED COVERAGE OF PARTLY-
MOSTLY CLOUDY SKIES SHOULD SLOWLY OVERTAKE THE CWA FROM SOUTHWEST-
NORTHEAST TODAY...WHILE THE LATEST HRRR LOW CLOUD COVER PRODUCT
SUGGESTS STRATUS COULD BE A MORE MINIMAL ISSUE AS ALTHOUGH IT
STILL BRINGS IT INTO MAINLY THE SOUTHWEST 1/2 TO 1/3 OF THE CWA IT
DIMINISHES IT AREA WITH TIME AND EVEN MIXES IT OUT ALMOST
COMPLETELY IN THE AFTERNOON. NOT SURPRISINGLY...THE OFFICIAL SKY
COVER FORECAST IS A HEDGE...SUGGESTING THAT THE DAY AS A WHOLE
STARTS OUT MOSTLY SUNNY IN MOST AREAS BUT THEN BECOMES AT LEAST
PARTLY CLOUDY WITH AT LEAST A BRIEF FEW HOURS OF MOSTLY CLOUDY
PASSING THROUGH. EVEN WITHOUT LOWER STRATUS...A FEW DECENT PATCHES
OF MID LEVEL CLOUDS COULD ALSO WORK OVERHEAD FROM THE NORTHWEST.
STAY TUNED FOR PLENTY OF SKY COVER FINE TUNING BY DAY SHIFT. HIGH
TEMP-WISE...FOLLOWED A BLEND OF VARIOUS MODELS/GUIDANCE TO YIELD
AROUND A 2-3 DEGREE RISE FROM PREV FORECAST...WHICH PUTS MOST OF
THE CWA IN THE 69-73 RANGE BUT WITH SLIGHTLY WARMER GENERALLY
74-77 IN FAR SOUTHWEST ZONES. BY THIS AFTERNOON SURFACE DEWPOINTS
SHOULD HAVE RISEN BACK UP SOMEWHERE IN THE 50S...HIGHEST
SOUTHWEST.
THIS EVENING-TONIGHT...THE MID-UPPER LEVEL STORY INVOLVES
CONTINUED FAIRLY STEADY-STATE NORTHWESTERLY FLOW ALOFT AS A VERY
LOW-AMPLITUDE/CHANNELED SHORTWAVE TROUGH SLIDES CLIPS THROUGH
MAINLY JUST TO THE NORTHEAST OF THE CWA ALONG A TRACK FROM THE
DAKOTAS THROUGH IA INTO NORTHERN MO. AS THIS WAVE PASSES BY...IT
WILL INDUCE A MODEST INCREASE IN THE LOW LEVEL JET AND ASSOCIATED
THETA-E ADVECTION/ISENTROPIC LIFT THAT WILL GRADUALLY VEER FROM
SOUTHWESTERLY TO MORE WESTERLY...ALTHOUGH THE MAIN NOSE OF THIS
FORCING LOOKS TO AIM EASTERN KS AND NOT SO MUCH LOCALLY. AS A
RESULT...THE MAJORITY OF BOTH DETERMINISTIC AND HIGHER RES-
SIMULATED REFLECTIVITY MODELS SUCH AS THE 4KM WRF-NMM FOCUS
OVERNIGHT CONVECTION AT LEAST A FEW COUNTIES EAST-SOUTHEAST OF THE
CWA. HOWEVER...GIVEN THAT THE PREVIOUS FORECAST ALREADY WAS
CARRYING A SLIGHT SHOWER/STORM CHANCE IN SOUTHEAST ZONES AND THAT
THE GFS IN PARTICULAR STILL TRIES TO INITIATE STORMS IN THIS
AREA...HAVE HELD ONTO THIS SLIGHT CHANCE MAINLY SOUTHEAST OF A
GENEVA-PLAINVILLE LINE POST-MIDNIGHT...BUT REMOVED ANY PRECIP
CHANCES EARLIER IN THE EVENING GIVEN THAT LIFT DOES NOT APPEAR
SUFFICIENT TO GENERATE CONVECTION BEFORE THEN. SHOULD ANY STORMS
BE REALIZED...CERTAINLY A FEW STRONG UPDRAFTS CAPABLE OF
PRODUCING AT LEAST NEAR-SEVERE HAIL CANNOT BE RULED OUT GIVEN THE
06Z NAM SUGGESTION OF UP TO AROUND 1500 J/KG MUCAPE IN THE
850-700MB LAYER AND AROUND 40KT OF DEEP LAYER SHEAR. AS A
RESULT...WILL CONTINUE TO MENTION NICKEL SIZE HAIL POTENTIAL IN
THE LOCAL HAZARDOUS WEATHER OUTLOOK IN SOUTHEAST AREAS...DESPITE
THE FACT THAT THE LATEST SPC DAY 1 OUTLOOK REMOVED THE 5 PERCENT
SEVERE PROBABILITY CONTOUR FROM THE CWA THAT HAD BEEN PRESENT ON
THE FORMER DAY 2 OUTLOOK. AGAIN THOUGH...NO MATTER WHAT THE
MAJORITY OF THE CWA SHOULD GET THROUGH THE NIGHT DRY. TURNING TO
THE SURFACE SITUATION...GENERALLY 5-8 MPH SOUTHEASTERLY BREEZES
THIS EVENING SHOULD BECOME EVEN LIGHTER AND MORE EASTERLY AFTER
MIDNIGHT. ASSUMING THAT OVERNIGHT SKIES AVERAGE NO WORSE THAN
PARTLY CLOUDY IN THE WAKE OF POTENTIAL EASTWARD-EXITING STRATUS
FROM THE DAYTIME HOURS...THE STAGE COULD BE SET FOR SOME
POTENTIALLY DECENT AT-LEAST-LIGHT FOG FORMATION...AND MAYBE SOME
MORE IMPACTFUL FOG ESPECIALLY WITHIN THE WESTERN 1/2 OF THE CWA
PER THE LATEST SREF VISIBILITY PROBABILITY PRODUCTS. EXPERIENCE
HAS SHOWN THAT FOG IS ALMOST NEVER A "SURE THING" UNTIL IT
ACTUALLY FORMS...BUT FELT IT WOULD BE PRUDENT TO INTRODUCE A
GENERIC PATCHY FOG WORDING TO ALL AREAS LATE TONIGHT...AND A
SOMEWHAT HARDER-HITTING AREAS OF FOG MENTION TO WESTERN COUNTIES.
ITS JUST TOO SOON TO SAY WHETHER OR NOT FOG COULD CAUSE IMPACTFUL
ISSUES FOR THE WED MORNING COMMUTE. AS FOR LOW TEMPS...MADE VERY
LITTLE CHANGE HERE...AS THE INCREASED LOW LEVEL MOISTURE SHOULD
HELP HOLD UP LOWS GENERALLY 5-10 DEGREES HIGHER THAN THIS
MORNING...AND AM CALLING FOR A RANGE FROM NEAR-50 FAR
NORTH...LOW-MID 50S CENTRAL AND NEAR 60 FAR SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 435 AM CDT TUE SEP 16 2014
THE WARMEST DAY OF THE NEXT 7 DAYS WILL BE FRIDAY WITH HIGHS IN THE
MID 80S AHEAD OF A COLD FRONT. THE BEST CHANCE OF
SHOWERS/THUNDERSTORMS CURRENTLY APPEARS TO BE ASSOCIATED WITH THAT
COLD FRONTAL PASSAGE FRIDAY NIGHT INTO THE FIRST HALF OF SATURDAY.
THE COOLEST DAY OF THE WEEK WILL ACTUALLY BE TODAY WITH HIGHS OF 70
TO 75. SO OVERALL THIS WILL BE A RATHER NICE WEEK WITH HIGHS NEAR
NORMAL FOR THIS TIME OF YEAR...WHICH IS GENERALLY IN THE UPPER 70S.
WEDNESDAY/WEDNESDAY NIGHT...AN UPPER LEVEL RIDGE WILL BE CENTERED
OVER THE ROCKIES WITH NORTHWESTERLY FLOW ALOFT ACROSS THE CENTRAL
PLAINS. THERE WILL BE DECENT INSTABILITY AND WIND SHEAR ACROSS OUR
FORECAST AREA...BUT FORCING IS RATHER WEAK. THERE MAY BE A WEAK
UPPER WAVE RIDING DOWN THE EAST SIDE OF THE RIDGE OR PERHAPS
SLIGHTLY BETTER LIFT AFTER DARK WEDNESDAY NIGHT AS A WEAK LOW LEVEL
JET LIFTS OVER THE EAST SOUTHEAST SFC FLOW. HOWEVER...THE BETTER LOW
LEVEL JET SET UP APPEARS TO BE TO OUR SOUTHEAST OVER NORTHEAST
KANSAS. SO OVERALL...FORCING JUST SEEMS RATHER QUESTIONABLE AND WILL
ONLY CARRY LOWER END POPS BEGINNING WEDNESDAY NIGHT WITH THE REALITY
BEING MOST LOCATIONS WILL MORE LIKELY THAN NOT BE DRY.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES WILL DECREASE. A FEW
FORECAST MODELS ARE STILL HINTING AT LOW END CHANCES OF
PRECIPITATION ACROSS OUR FORECAST AREA...BUT AM NOT VERY OPTIMISTIC
THAT THERE WILL BE MUCH OUT THERE GIVEN THE RIDGE MOVING IN.
THEREFORE...DECREASED OUR POPS AND DOWNGRADED SHOWER AND
THUNDERSTORM CHANCES TO JUST ISOLATED SPRINKLES.
FRIDAY THROUGH SATURDAY...AS MENTIONED ABOVE...FRIDAY WILL BE THE
WARMEST DAY OF THE NEXT 7 DAYS AS GUSTY SOUTHERLY WINDS PUMP WARMER
AIR INTO THE REGION AHEAD OF AN APPROACHING COLD FRONT. AN
INTERESTING WRINKLE IN THIS FORECAST IS WHAT WILL HAPPEN WITH THE
REMNANTS OF HURRICANE ODILE...WHICH IS CURRENTLY LOCATED OVER THE
BAJA PENINSULA OF MEXICO. THE 00Z GFS AND 00Z ECMWF BOTH BRING
REMNANT MOISTURE FROM THIS DECAYING TROPICAL SYSTEM NORTH NORTHEAST
INTO THE CENTRAL PLAINS...WHERE IT WILL WORK INTO AN UPPER LEVEL
STORM SYSTEM THAT IS TRACKING EAST THROUGH THE CENTRAL PLAINS. THERE
ARE STILL PLENTY OF QUESTIONS WITH REGARD TO THE TIMING OF WHEN THE
TROPICAL MOISTURE PLUME WILL ARRIVE AND HOW THAT WILL INTERACT WITH
OUR MID LATITUDE UPPER TROUGH. THE MOST LIKELY TIME FOR
PRECIPITATION WILL BE FROM FRIDAY NIGHT THROUGH SATURDAY
MORNING...WITH THE SYSTEM EXITING TO OUR EAST BY SATURDAY AFTERNOON.
TEMPERATURES WILL BE SLIGHTLY COOLER SATURDAY BEHIND THE COOL
FRONT...BUT NOTHING MAJOR WITH HIGHS ONLY AROUND 5F COOLER.
SUNDAY THROUGH MONDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH DRY WEATHER LIKELY FOR OUR FORECAST AREA. HIGH
TEMPERATURES WILL BE NEAR NORMAL IN THE 70S.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1258 PM CDT TUE SEP 16 2014
LATEST OBS/VIS SATL SHOWING AREA OF MVFR CIGS GRADUALLY FILLING IN
ACROSS S-CNTRL NEB AND HAVE ALREADY REACHED KGRI AND KEAR. GIVEN
MOVEMENT TRENDS THE LAST SEVERAL HOURS...EXPECT GRADUAL CLEARING AT
BOTH TERMINALS BY LATE THIS AFTN. OTHERWISE...MAIN AVN CONCERN IS
DETERIORATING CONDITIONS EARLY WED MORNING. COMBINATION OF CLEAR
SKIES AND LIGHT WINDS WILL ALLOW FOR MVFR VSBYS TO SETTLE IN AT BOTH
KGRI/KEAR BTWN 09Z-14Z. AFT 14Z THEN...VFR CONDITIONS EXPECTED THE
REMAINDER OF THE FCST PD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
102 PM CDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 101 PM CDT TUE SEP 16 2014
NO CHANGES.
UPDATE ISSUED AT 1005 AM CDT TUE SEP 16 2014
BAND OF MID CLOUDS ACROSS MANITOBA INTO FAR NRN MN. AREA DEFINED
WELL BY LATEST RAP MODEL AND SHOWS CLOUDS HOLDING IN THAT AREA
THRU THE DAY. OTHERWISE SHOULD BE SUNNY. TEMPS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 253 AM CDT TUE SEP 16 2014
MAIN CHALLENGE FOR TODAY WILL REVOLVE AROUND THE BAND OF MID
CLOUDS MOVING INTO THE FAR NORTHERN FA NOW. OTHERWISE NEXT CHANCE
OF PCPN LOOKS TO BE SLIGHTLY MORE DELAYED...ARRIVING MORE THU
AFTERNOON INTO THU NIGHT. AS MENTIONED THERE IS A BAND OF MID
CLOUDS NOW MOVING INTO THE LAKE OF THE WOODS REGION. MODELS KEEP
SOME MID LEVEL MOISTURE IN A NW TO SE BAND TODAY...MAINLY
ASSOCIATED WITH THE THERMAL GRADIENT AND A WEAK SHORT WAVE UNDER
THE NORTHWEST FLOW ALOFT. THEREFORE WILL KEEP MORE CLOUDS
MENTIONED IN THE FAR NORTH AND NE. SHOULD SEE MORE SUN IN OTHER
AREAS WITH HIGH TEMPS IN THE MID 60S TO LOW 70S. SOME OF THESE MID
CLOUDS MAY ALSO LINGER INTO TONIGHT IN THE SAME GENERAL AREA ALONG
WITH PRETTY LIGHT WINDS. MAY EVEN BE A FEW SPRINKLES OR LIGHT
SHOWERS AROUND THE LAKE OF THE WOODS REGION SO DID ADD THAT TO THE
FORECAST THERE LATE TONIGHT INTO EARLY WED. THE TIGHTER THERMAL
GRADIENT ALSO PUSHES INTO THE NORTHEAST FA ON WED WHICH SHOULD
BRING A LITTLE COOLER TEMPS TO THE NORTH AND NE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 253 AM CDT TUE SEP 16 2014
START TO SEE RETURN FLOW WED NIGHT WITH STEADY WARM ADVECTION IN
ALL AREAS. THIS WILL SET THU UP TO BE ANOTHER WARM DAY WITH HIGHS
MORE IN THE LOW TO MID 70S. INCREASING SFC PRESSURE GRADIENT
SHOULD ALSO RESULT IN FAIRLY BREEZY SOUTH WINDS. MODELS CONTINUE
TO SCALE BACK ON PCPN CHANCES SO DID REMOVE THEM FROM THE THU
MORNING TIME FRAME. STILL SOME UNCERTAINTY FOR THIS AREA THU
AFTERNOON WITH THE MAIN SFC FOCUS STILL BACK OVER THE WESTERN HIGH
PLAINS. 700MB TEMPS RISE TO +10C OVER MOST OF CENTRAL AND WESTERN
ND WITH VALUES A LITTLE LOWER INTO NORTHWEST MN. THIS MAY CAP ANY
CONVECTION WITH THE SFC FORCING OUT WEST. HOWEVER WITH THE
UNCERTAINTY DID KEEP WITH CONTINUITY AND LEFT THE ISOLATED THUNDER
POTENTIAL THU AFTERNOON. THE WARM 700MB TEMPS CREST OVER THE FA
THU NIGHT ALONG WITH STEADY 850MB WARM ADVECTION/INCREASING
MOISTURE VALUES. THE SFC BOUNDARY WILL ALSO MOVE INTO THE WESTERN
FA BY FRI MORNING BRINGING A LITTLE BETTER CHANCE FOR SHOWERS AND
TSTMS.
FOR FRI THROUGH MON NIGHT...THE PERIOD WILL START WITH SOME SHOWERS
AND STORMS WITH A SHORTWAVE AND DEEPER MOISTURE IN PLACE. EACH MODEL
RUN INDICATES MORE SCATTERED NATURE TO ANY CONVECTION FRIDAY...WITH
THE BEST CHANCES IN THE SOUTH AND EAST. A COOL FRONT WILL MOVE
THROUGH THE REGION ON SAT...AND THERE COULD BE MORE SHOWERS. DRIER
AND SLIGHTLY COOLER WEATHER WILL MOVE IN FOR SUNDAY...BEFORE ANOTHER
WARMING TREND AND DRY WEATHER NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 101 PM CDT TUE SEP 16 2014
CLEAR SKIES WITH SOME MID CLOUD ALONG THE INTL BORDER THAT SHOULD
DRY UP BY THIS EVENING...LIGHT SOUTHERLY WINDS EXPECTED THROUGH TAF
PD AS SFC HIGH MOVES FROM MANITOBA INTO WRN ONTARIO.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
228 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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1219 PM CDT TUE SEP 16 2014
AREA UNDER HIGH PRESSURE WITH LIGHT WINDS AND MAINLY CLEAR SKIES.
ONLY A FEW CUMULUS TODAY. MAIN FORECAST CONCERN FOR THE TAF PERIOD
IS POTENTIAL FOR VALLEY FOG AGAIN TONIGHT AT KLSE. SITUATION IS
DIFFERENT THAN LAST NIGHT`S GOOD EVENT. MOISTURE IS LESS...
FORECAST T/TD DEPRESSION IS NEARLY 10 DEG DURING THE EVENING. BOUNDARY
LAYER WIND IS HIGHER...WITH 15-20 KTS AT 1000 FT. PREVIOUS FORECAST
HAD GONE WITH 1SM BR OVERNIGHT BUT NOT CONFIDENT THAT WILL
MANIFEST. FEEL WE WILL DECOUPLE EARLY AND PERHAPS EVEN FORM SOME
BCFG NEAR KLSE BY 06Z. BUT WIND WILL KEEP IT FROM DEVELOPING
FURTHER...AND LACK OF MOISTURE LOOKING TO PRECLUDE WIDESPREAD
STRATUS. SOME INDICATION THAT WARM ADVECTION WILL HELP GENERATE
SOME PATCHY CLOUD COVER OVERNIGHT WHICH WOULD LIMIT RADIATION.
HAVE OPTED TO BACK OUT OF ANY FOG FOR NOW. BUT LATER SHIFTS WILL
NEED TO MONITOR IF WIND FIELD SLACKENS. IF THE FOG/STRATUS DOES
INDEED FORM...INVERSION MAY ALLOW IT TO EXPAND AND DEVELOP
FURTHER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW