Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/18/14
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
647 PM CDT WED SEP 17 2014
.AVIATION...
CONVECTION WILL REMAIN ACROSS THE WEST THIS EVENING..AND HAVE VCTS
IN THE TWO WESTERN TAFS THROUGH THE EVENING HOURS. SHORT TERM
GUIDANCE HAS A BREAK IN THE CONVECTION...BEFORE ANOTHER SYSTEM
POTENTIALLY DEVELOPS OVERNIGHT. DUE TO LOW CONFIDENCE...HAVE VCSH
ACROSS THE NORTH. MVFR CONDITIONS WILL DEVELOP ACROSS THE NORTHERN
HALF WITH THE LOW LEVEL MOISTURE OVERNIGHT...AND MAY BECOME IFR.
&&
.PREV DISCUSSION... /ISSUED 149 PM CDT WED SEP 17 2014/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
AREA OF SHRA/TSRA ONGOING ACROSS SRN MO IS BEGINNING TO ACCELERATE
AS THE STRONGEST CELLS ALONG THE WRN HALF OF THIS COMPLEX DROPS SOUTH
INTO AR. SEVERAL OF THE RECENT RUNS OF THE HIGH-RES HRRR HAVE DONE A
REASONABLE JOB ON THESE FEATURES...AND SHOW THIS ACTIVITY DROPPING
GENERALLY SOUTH THROUGHOUT THE AFTERNOON HRS. EXPECTING THIS
ACTIVITY TO GENERALLY FOLLOW THE HIGHER INSTABILITY AXIS ACROSS
THE WRN HALF TO TWO-THIRDS OF THE STATE WHERE MOST UNSTABLE CAPE
VALUES ARE ON THE ORDER OF 1-3K J/KG AT THIS HR. AS A RESULT...DO
HAVE HIGHEST POPS THROUGH MID AFTERNOON OVER THE NRN AND NWRN
SECTIONS OF THE CWA...THEN DROPPING SOUTH TO SW OVER TIME LATER
THIS AFTERNOON. THE HRRR SOLUTIONS EVEN KEEP THIS ACTIVITY GOING
INTO THE SWRN SECTIONS OF THE AREA BY THIS EVENING...SO HAVE
GENERALLY FOLLOWED THIS TREND WITH POPS. HOWEVER...DO DROP POPS
OVER TIME AS UNCERTAINTY IN COVERAGE AN INTENSITY INCREASES BY
LATE THIS EVENING REGARDING THIS ONGOING CONVECTIVE ACTIVITY.
BEYOND THIS EVENING...THE TIMING AND PLACEMENT OF WHAT MAY BE THE
NEXT UPPER DISTURBANCE MOVING OVER THE STATE BECOMES A BIT
UNCERTAIN. EARLIER SHORT TERM MODEL SOLUTIONS HAVE THE NEXT WAVE
MOVING OVER LATE TONIGHT INTO THU MORNING...BUT THIS MAY NOT BE THE
CASE WITH THE ONGOING ACTIVITY AND ITS EXPECTED PATH. THE NEXT WAVE
MAY BE DELAYED A BIT LONGER...BUT MAY ALSO NOT BE AS INTENSE AS
EARLIER EXPECTED. WITH THAT SAID...CONTINUE WITH GENERALLY LOCATION
OF CHANCE POPS FOR MUCH OF THU...BUT HAVE DECREASED POPS SOME AS A
RESULT OF THE UNCERTAINTY OF WHEN/WHERE THE NEXT WAVE MAY MOVE.
BY FRI INTO EARLY SAT...AN UPPER RIDGE WILL MOVE OVER THE
REGION...DECREASING POPS AND INCREASING TEMPS ACROSS THE STATE. BY
LATE IN THE PERIOD THOUGH...HAVE INCREASING POPS WITH THE APPROACH
OF AN UPPER LOW OR THE REMNANTS OF ODILE AS THEY APPROACH FROM THE
WEST/NW.
LONG TERM...SUNDAY THROUGH WEDNESDAY
A COLD FRONT WILL BE MAKING ITS WAY THROUGH THE STATE AT THE START
OF THE LONG TERM...WITH SOME RAIN CHANCES MAKING THEIR WAY INTO THE
AREA THROUGH MONDAY AFTERNOON. THOUGH...LATEST MODEL SOLUTIONS SEEM
LESS AMBITIOUS ABOUT WIDESPREAD RAINFALL IN THE STATE.
AS RAIN CHANCES DISSIPATE BY MONDAY...COOLER AIR WILL FILTER INTO THE
STATE. BOTH HIGH AND LOW TEMPERATURES WILL BE FAIRLY NORMAL TO
SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF SEPTEMBER IN ARKANSAS.
WINDS WILL GENERALLY BE OUT OF THE NORTH THROUGH THE EXTENDED PERIOD
AND A COOL NORTHWEST FLOW ALOFT WILL BE IN PLACE.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...58
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 DENVER/BOULDER CO
844 PM MDT WED SEP 17 2014
.UPDATE...
ISSUED AT 844 PM MDT WED SEP 17 2014
CONVECTIVE ACTIVITY DIMINISHING NOW....WITH ONLY A FEW SHOWERS AND STORMS
LEFT IN WASHINGTON...SEDGWICK AND DOUGLAS COUNTIES. THESE SHOULD
BE DISSIPATED WITHIN THE NEXT HOUR. SKIES TO CLEAR WITH SOME
MOISTURE ADVECTION INTO THE NORTHEAST CORNER OF THE STATE STILL
EXPECTED. HAVE UPDATED THE NEAR TERM GRIDDED FORECAST FOR THIS AND
TO CLEAR SKIES QUICKER.
UPDATE ISSUED AT 548 PM MDT WED SEP 17 2014
FOR AVIATION DISCUSSION.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 220 PM MDT WED SEP 17 2014
CONVERGENCE BOUNDARY CONTINUES TO SPARK SCATTERED SHOWERS AND
THUNDERSTORMS OVER ELBERT AND LINCOLN COUNTIES THIS AFTERNOON.
ADDITIONAL OUTFLOW BOUNDARIES FROM THE SHOWERS WILL HELP TO AID
IN ADDITIONAL DEVELOPMENT FOR THE REST OF THE AFTERNOON AND EARLY
EVENING. THE OTHER AREA FOR POTENTIAL STORMS IS OVER THE
CYS RIDGE AND FAR NORTHEAST PLAINS. STRONGER STORMS IN WYOMING
EXPECTED TO MOVE INTO THE FAR NE PLAINS LATER THIS AFTERNOON AND
TAP INTO A BIT HIGHER LOW LEVEL MOISTURE. THIS MAY LEAD TO A
STRONGER/POTENTIAL ISOLATED SEVERE STORM WITH SURFACE BASED CAPES
OF 800-1500J/KG. LATEST HRRR STILL SUGGESTS ISOLATED THUNDERSTORMS
OVER THE NE PLAINS AND WILL EXPAND COVERAGE A BIT FOR EVENING
FORECAST BASED ON LATEST TRENDS.
A RIDGE OF HIGH PRESSURE WILL CENTER ITSELF OVER CO ON THURSDAY.
INCREASING MID LEVEL SUBSIDENCE ASSOCIATED WITH THE RIDGE MAY NIX
AFTN TSTM COMPLETELY FM THE FORECAST. SOME LOW LOW MOISTURE IS
PROGGED TO ADVECT INTO THE NORTHEAST CORNER OF THE STATE LATE
TONIGHT AND EARLY THURSDAY MORNING SO WL KEEP THE MENTION OF
PATCHY FOG THERE AS WELL. HIGH TEMPERATURES SIMILAR TO
TODAY...MAYBE EVEN A DEGREE OR TWO WARMER WITH LESS SUBTROPICAL
MOISTURE AROUND.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1013 AM MDT WED SEP 17 2014
THE UPPER LEVEL RIDGE WILL BREAK DOWN AND MOVE EASTWARD THROUGH
FRIDAY. FLOW WILL BE FROM THE SSW WITH THE LOW OVER THE SW COMING
IN UNDER THE RIDGE. THIS SYSTEM WILL REMAIN TO THE SOUTH WITH MOST
OF THE MOISTURE COMING BEHIND THE SURFACE FRONT THAT WILL MOVE
THROUGH FRIDAY. THE FRONT WILL BRING IN STRONG SOUTHERLY FLOW TO
THE EASTERN PORTIONS OF THE REGION WITH INCREASED MOISTURE BEHIND
IT. THERE IS ALSO SOME WEAK QG LIFT BEHIND THE FRONT THAT WILL
ALLOW FOR SOME SHOWER/TS DEVELOPMENT OVER THE MOUNTAINS AND
FOOTHILLS FRIDAY AFTERNOON AND EVENING.
FOR SATURDAY SUBSIDENCE AND DOWNSLOPE WINDS BEHIND THE FRONT WITH
UPPER LEVEL RIDGING RETURNING WILL HELP TO DRY THINGS OUT AND KEEP
TEMPS AT OR JUST ABOVE SEASONAL NORMALS. ON SUNDAY FLOW AROUND THE
UPPER RIDGE WILL COMBINE WITH MOISTURE OUT AHEAD OF THE NEXT
SYSTEM MOVING INTO THE GREAT BASIN BY SUNDAY AFTERNOON TO KEEP THE
WEATHER UNSETTLED THROUGH THE PERIOD. FOR SUNDAY THERE IS A SLIGHT
CHANCE OF TS DURING THE AFTERNOON WITH TEMPS IN THE MID 70S
BECOMING COOLER ON MONDAY.
THE UPPER TROUGH/CLOSED LOW WILL TRACK IN BY MONDAY AFTERNOON
WITH PWS RANGING FROM 0.90-1.00 AND DEWPOINTS IN THE MID 50S BY
12Z MONDAY. THIS COMBINED WITH DECENT QG LIFT WILL BRING A GOOD CHANCE
OF WIDESPREAD SHOWERS/TS ON MONDAY THROUGH TUESDAY AS THE LOW
CONTINUES TO TRACK TOWARD THE NE. TEMPS WILL BE AT OR BELOW
SEASONAL NORMALS IN THE LOWER 70S AT THE START OF THE WEEK SLOWLY
INCREASING BY WEDNESDAY BACK TO THE UPPER 70S AND LOWER 80S.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 844 PM MDT WED SEP 17 2014
VFR CONDITIONS THROUGH THE PERIOD. VARIABLE WINDS OCCURRING AT
THE AREA AIRPORTS IN THE WAKE OF CONVECTIVE OUTFLOWS. TOUGH CALL
ON WHICH WIND WILL WIN OUT OVER DEN...AS NORTHWEST WINDS TO THE
NORTHWEST...AND SOUTHWEST WINDS TO THE SOUTHWEST COULD BOTH MAKE
IT IN. FOR NOW WILL GO WITH PERSISTENCE AND LEAVE SOUTHEAST WINDS
IN. OVERALL...SHOULD SEE DRAINAGE WINDS PREVAIL BY 06Z. A
DEEPENING TROUGH OVER THE PLAINS WILL BRING STRONG AND GUSTY
SOUTHERLY WINDS THURSDAY. NO STORMS ARE EXPECTED THURSDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KRIEDERMAN
SHORT TERM...ENTREKIN/COOPER
LONG TERM...BOWEN
AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
551 PM MDT WED SEP 17 2014
.UPDATE...
ISSUED AT 548 PM MDT WED SEP 17 2014
FOR AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 220 PM MDT WED SEP 17 2014
CONVERGENCE BOUNDARY CONTINUES TO SPARK SCATTERED SHOWERS AND
THUNDERSTORMS OVER ELBERT AND LINCOLN COUNTIES THIS AFTERNOON.
ADDITIONAL OUTFLOW BOUNDARIES FROM THE SHOWERS WILL HELP TO AID
IN ADDITIONAL DEVELOPMENT FOR THE REST OF THE AFTERNOON AND EARLY
EVENING. THE OTHER AREA FOR POTENTIAL STORMS IS OVER THE
CYS RIDGE AND FAR NORTHEAST PLAINS. STRONGER STORMS IN WYOMING
EXPECTED TO MOVE INTO THE FAR NE PLAINS LATER THIS AFTERNOON AND
TAP INTO A BIT HIGHER LOW LEVEL MOISTURE. THIS MAY LEAD TO A
STRONGER/POTENTIAL ISOLATED SEVERE STORM WITH SURFACE BASED CAPES
OF 800-1500J/KG. LATEST HRRR STILL SUGGESTS ISOLATED THUNDERSTORMS
OVER THE NE PLAINS AND WILL EXPAND COVERAGE A BIT FOR EVENING
FORECAST BASED ON LATEST TRENDS.
A RIDGE OF HIGH PRESSURE WILL CENTER ITSELF OVER CO ON THURSDAY.
INCREASING MID LEVEL SUBSIDENCE ASSOCIATED WITH THE RIDGE MAY NIX
AFTN TSTM COMPLETELY FM THE FORECAST. SOME LOW LOW MOISTURE IS
PROGGED TO ADVECT INTO THE NORTHEAST CORNER OF THE STATE LATE
TONIGHT AND EARLY THURSDAY MORNING SO WL KEEP THE MENTION OF
PATCHY FOG THERE AS WELL. HIGH TEMPERATURES SIMILAR TO
TODAY...MAYBE EVEN A DEGREE OR TWO WARMER WITH LESS SUBTROPICAL
MOISTURE AROUND.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1013 AM MDT WED SEP 17 2014
THE UPPER LEVEL RIDGE WILL BREAK DOWN AND MOVE EASTWARD THROUGH
FRIDAY. FLOW WILL BE FROM THE SSW WITH THE LOW OVER THE SW COMING
IN UNDER THE RIDGE. THIS SYSTEM WILL REMAIN TO THE SOUTH WITH MOST
OF THE MOISTURE COMING BEHIND THE SURFACE FRONT THAT WILL MOVE
THROUGH FRIDAY. THE FRONT WILL BRING IN STRONG SOUTHERLY FLOW TO
THE EASTERN PORTIONS OF THE REGION WITH INCREASED MOISTURE BEHIND
IT. THERE IS ALSO SOME WEAK QG LIFT BEHIND THE FRONT THAT WILL
ALLOW FOR SOME SHOWER/TS DEVELOPMENT OVER THE MOUNTAINS AND
FOOTHILLS FRIDAY AFTERNOON AND EVENING.
FOR SATURDAY SUBSIDENCE AND DOWNSLOPE WINDS BEHIND THE FRONT WITH
UPPER LEVEL RIDGING RETURNING WILL HELP TO DRY THINGS OUT AND KEEP
TEMPS AT OR JUST ABOVE SEASONAL NORMALS. ON SUNDAY FLOW AROUND THE
UPPER RIDGE WILL COMBINE WITH MOISTURE OUT AHEAD OF THE NEXT
SYSTEM MOVING INTO THE GREAT BASIN BY SUNDAY AFTERNOON TO KEEP THE
WEATHER UNSETTLED THROUGH THE PERIOD. FOR SUNDAY THERE IS A SLIGHT
CHANCE OF TS DURING THE AFTERNOON WITH TEMPS IN THE MID 70S
BECOMING COOLER ON MONDAY.
THE UPPER TROUGH/CLOSED LOW WILL TRACK IN BY MONDAY AFTERNOON
WITH PWS RANGING FROM 0.90-1.00 AND DEWPOINTS IN THE MID 50S BY
12Z MONDAY. THIS COMBINED WITH DECENT QG LIFT WILL BRING A GOOD CHANCE
OF WIDESPREAD SHOWERS/TS ON MONDAY THROUGH TUESDAY AS THE LOW
CONTINUES TO TRACK TOWARD THE NE. TEMPS WILL BE AT OR BELOW
SEASONAL NORMALS IN THE LOWER 70S AT THE START OF THE WEEK SLOWLY
INCREASING BY WEDNESDAY BACK TO THE UPPER 70S AND LOWER 80S.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z THURSDAY LATE AFTERNOON)
ISSUED AT 548 PM MDT WED SEP 17 2014
MODERATE OUTFLOW BOUNDARY APPROACHING TERMINALS THIS EVENING AND
WILL BE THROUGH BETWEEN 0030 AND 0140Z WITH WINDS FROM THE NORTH
AND NORTHEAST OF 10-22KT. THERE ARE SOME SHOWER ACTIVITY NORTH OF
THE BOUNDARY BUT STILL UNSURE HOW MUCH OF THIS WILL REDEVELOP
BEHIND BOUNDARY AS IT PUSHES OVER TERMINALS. WILL LEAVE TAFS DRY
FOR NOW BUT WILL MONITOR IN CASE TS OR ADDITIONAL OUTFLOW SHOWERS
ARE NEEDED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ENTREKIN
SHORT TERM...ENTREKIN/COOPER
LONG TERM...BOWEN
AVIATION...ENTREKIN
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 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 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 BOISE ID
840 PM MDT WED SEP 17 2014
.DISCUSSION...WARM UNDER THE CLOUDS THIS EVENING...WITH A FEW
LIGHT SHOWERS ALREADY IN THE WESTERN MAGIC VALLEY AND SRN TWIN
FALLS COUNTY. LATEST NAM AND HRRR MODELS INSIST THAT SHOWERS WILL
FORM OVERNIGHT ACROSS MUCH OF THE AREA...ESPECIALLY SE OREGON.
ALREADY SEEING ENOUGH OF AN INCREASE IN CLOUD AND SHOWER/STORM
ACTIVITY TO THE SOUTH TO MAKE IT SOMEWHAT BELIEVABLE. THEREFORE
WILL UPDATE THE FORECAST TO INCREASE POPS MOST AREAS. OTHERWISE
THE FRONT MAY BE EVEN WEAKER THAN PREVIOUSLY THOUGHT OWING TO THE
STRENGTH OF THE TROUGH AND ITS ASSOCIATED SLOWER TIMING. LATEST
GUIDANCE IS POINTING AT A BARELY NOTICEABLE FROPA AFTER AROUND 12Z
IN SE OREGON AND INTO THE AFTERNOON IN SW IDAHO. A SECOND...STRONGER
FRONT APPEARS HEADED IN THU NIGHT. UPDATE OUT SHORTLY.
&&
.AVIATION...VFR. INCREASING AND LOWERING CLOUDS. AFTER 06Z FOR
SOUTHWEST IDAHO AND AFTER 09Z FOR SOUTHEAST OREGON...SCATTERED
SHOWERS WILL SPREAD NORTH WITH LOCAL MVFR CONDITIONS AND ISOLATED
MOUNTAIN OBSCURATION. ISOLATED THUNDERSTORMS OVER SOUTHWEST IDAHO.
SURFACE WINDS TONIGHT WILL GENERALLY BE 10 KNOTS OR LESS...WITH
GUSTY WINDS NEAR SHOWERS AND THUNDERSTORMS. WINDS ALOFT WILL BE
SOUTHWESTERLY AROUND 25 KNOTS UP THROUGH 10K FEET MSL.
&&
.PREV DISCUSSION...
SHORT TERM...AFTERNOON TEMPS ARE APPROACHING FORECAST HIGHS DESPITE
EXTENSIVE HIGH CLOUDINESS FROM UPPER TROUGH OFF THE OREGON COAST. A
LOW HAS FORMED IN THE TROUGH NEAR 39/130 WHICH WILL HELP SPLIT THE
TROUGH AS IT MOVES INLAND THURSDAY. THE LOW ITSELF WILL GO DOWN THE
CALIF COAST THU AND FRI WHILE THE NORTHERN PORTION OF THE TROUGH
SHEARS EAST INTO MONTANA...LEAVING OUR CWA IN THE COL BETWEEN THEM.
WEAK SURFACE COLD FRONT WILL PRODUCE A SLIGHT CHANCE OF SHOWERS IN
OUR OREGON ZONES LATE TONIGHT AND IN IDAHO ZONES THURSDAY. MAIN
INSTABILITY FOR THUNDERSTORMS WILL BE IN ERN-MOST IDAHO ZONES
TONIGHT AND THURSDAY BUT INSTABILITY AND VERTICAL SHEAR WILL LIMIT
MENTION TO ONLY A SLIGHT CHANCE. HOWEVER A BETTER CHANCE WILL EXIST
IN SRN TWIN FALLS COUNTY AND SERN OWYHEE COUNTY THURSDAY AFTERNOON
AND EVENING WHERE MOISTURE MAY BE ENTRAINED FROM WEAKENING TROPICAL
STORM ODILE IN ARIZONA. MODELS HAVE SURPRISINGLY LITTLE INSTABILITY
ON OUR NRN BORDER THURSDAY EVEN THOUGH THE UPPER TROUGH WILL BE
NEARBY. DRYING FROM THE WEST LATE THURSDAY NIGHT AND FRIDAY. TEMPS
WILL BE ABOVE NORMAL AGAIN TONIGHT DUE TO CLOUD COVER. MAX TEMPS
THURSDAY WILL COOL 8-10 DEGREES FROM TODAY WITH A FEW DEGREES
FURTHER COOLING OF BOTH MIN AND MAX TEMPS FRIDAY.
LONG TERM...
FRIDAY EVENING THROUGH SUNDAY...EXPECT SOUTHEAST OREGON AND
SOUTHWEST IDAHO TO BE DRY AND MILD. HIGHS WILL RUN AROUND 5 ABOVE
NORMAL. SKIES SHOULD BE MOSTLY CLEAR OR SUNNY. THIS IS DUE TO AN
UPPER LEVEL RIDGE CURRENTLY ABOUT 2000 MILES WSW OF BOISE...THAT
BUILDS NORTHEASTWARD LATE THIS WEEK ACROSS THE PACNW AND EVENTUALLY
SPREADS TO INTERIOR SW CANADA AS WELL FOR THE WEEKEND. THIS LEAVES
OUR AREA OPEN TO INFLUENCE /MOISTURE INSTABILITY AND LIFT/ FROM THE
UPPER LOW MEANDERING FROM OUR W TO S IN THE SHORT TERM. PREFER A
GEFS/EC/GFS BLEND. SO THE LOW NOW IS EXPECTED TO LIFT NNE TO THE NV-
ID BORDER SUNDAY MORNING AND ACROSS SW- TO S-CENTRAL IDAHO SUNDAY
THROUGH MONDAY RESPECTIVELY WITH SCATTERED MAINLY MOUNTAIN SHOWERS
AND ISOLATED THUNDERSTORMS. THEN THROUGH WEDNESDAY...TEMPERATURES
WILL CONTINUE TO BE ABOUT 5-7 DEGREES ABOVE NORMAL AND A SLIGHT
CHANCE OF PRECIPITATION WILL LINGER IN THE WEST CENTRAL MOUNTAINS
FROM THE CUTOFF LOW. MODELS AGREE THAT A TROUGH COMING OUT OF THE
NE PACIFIC WILL MOVE IN BY WEDNESDAY EVENING BRINGING AROUND A HALF
AN INCH OF PRECIPITATION TO MUCH OF SE OREGON/WEST CENTRAL MOUNTAINS/
BOISE MOUNTAINS. COOLER TEMPERATURES WILL ACCOMPANY THE ASSOCIATED
FRONT...BRINGING US TO JUST A FEW DEGREES ABOVE NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING ORZ636.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...SP
AVIATION.....JA
PREV SHORT TERM...LC
PREV LONG TERM....VM/AB
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 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:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
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.
&&
$$
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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 GOODLAND KS
545 PM MDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 143 PM MDT WED SEP 17 2014
WEAK CONVECTION CURRENTLY DEVELOPING IN EASTERN COLORADO ALONG
PALMER DIVIDE AND WEAK WIND CONVERGENT ZONE WILL MOVE INTO
WESTERN KANSAS THIS AFTERNOON. INITIALLY HIGHER BASED CONVECTION
IN KIT CARSON COUNTY WHERE DEWPOINTS ARE IN THE UPPER 30S SHOULD
EVENTUALLY REACH BETTER MOISTURE AS IT WORKS EAST WHERE DEWPOINTS
ARE IN THE LOW-MID 50S. HRRR RUNS ALL MORNING HAVE CONTINUED TO
INDICATE THE POTENTIAL FOR SCATTERED SHRA/TSRA MAINLY SOUTH OF
I-70 IN KANSAS UNTIL EARLY EVENING. NAM HINTS AT THIS AS WELL.
BOTTOM LINE...HAVE INCLUDED LOW POPS TO ACCOUNT FOR THIS BUT FORCING
APPEARS WEAK AND SOME CINH REMAINS TO BE OVERCOME. OVERALL NOT
EXPECTING A BIG CONVECTIVE EVENT HERE.
WIDESPREAD STRATUS AND LOCALLY DENSE FOG IS LIKELY TO DEVELOP OVER
THE EASTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. SURFACE
DEWPOINTS WILL HOLD IN THE UPPER 50S AND LOWER 60S WITH CONTINUED
LIGHT SOUTHEAST BOUNDARY LAYER FLOW.
POTENTIAL EXISTS FOR OVERNIGHT CONVECTION...MAINLY AFTER MIDNIGHT...
EAST OF A TRENTON NEBRASKA TO HOXIE KANSAS LINE. GFS/NAM GUIDANCE
BOTH GIVE SUPPORT TO A SSE-NNW ORIENTED BAND OF SHOWERS AND
THUNDERSTORMS...ALTHOUGH TIMING AND PLACEMENT DIFFERS SOMEWHAT
BETWEEN MODELS. 500-1000 J/KG OF ELEVATED CAPE IS PRESENT TO
SUPPORT CONVECTION IF INHIBITION IS OVERCOME.
TEMPERATURES SHOULD CHANGE LITTLE NEXT COUPLE DAYS AS UPPER RIDGE
OVER THE ROCKIES SHIFTS EAST TO THE CENTRAL HIGH PLAINS. HIGHS
THURSDAY WILL AGAIN BE ABOVE NORMAL AROUND 90F GIVEN FORECAST 850
MB TEMPS 26-30C.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED SEP 17 2014
THURSDAY NIGHT-SATURDAY...FOCUS FOR THIS PORTION OF THE FORECAST IS
THE TRACK OF WHATS NOW WEAKENING TROPICAL STORM ODILE.
DEEP MOISTURE (WITH PRECIPITABLE WATER VALUES AROUND 1.5 INCHES)
ASSOCIATED WITH THE REMNANTS OF THIS SYSTEM ARE FORECAST TO REACH
AREAS SOUTH OF INTERSTATE 70 LATE FRIDAY AFTERNOON...SLIDING SLOWLY
EAST FRIDAY NIGHT AND OUT OF THE AREA EARLY SATURDAY MORNING. THE
GFS IS SLIGHTLY FURTHER SOUTH WITH THE PLUME OF MOISTURE COMPARED TO
THE 12Z NAM/00Z ECMWF...SO NO SLAM DUNK ON PRECIPITATION AMOUNTS
WITH THIS SYSTEM NOR HOW HIGH TO GO WITH POPS. IT APPEARS THAT
EITHER WAY...AS MENTIONED ABOVE...HIGHEST POPS WILL BE ALONG OR
SOUTH OF THE INTERSTATE. SOME LOCALLY HEAVY RAINFALL IS POSSIBLE IF
THE FURTHER NORTH NAM/ECMWF VERIFY.
SOUTH TO SOUTHWEST WINDS FRIDAY MID MORNING THROUGH AFTERNOON
GUSTING IN THE 25-35 MPH RANGE.
FOR SATURDAY AFTERNOON SOME MOISTURE MOVES IN FROM THE NORTHWEST
ASSOCIATED WITH AN UPPER TROUGH PASSAGE. CANT RULE OUT A FEW SHOWERS
AND MAYBE A THUNDERSTORM WITH IT WITH SLIGHT CHANCE POPS AT BEST.
SATURDAY NIGHT...DRY WITH MAYBE SOME HIGH CLOUDS MOVING IN FROM THE
WEST/SOUTHWEST.
LOWS THURSDAY NIGHT MID 50S TO MID 60S WITH SIMILAR...MAYBE A TAD
COOLER READINGS FRIDAY NIGHT.
HIGHS FRIDAY IN THE 80S WITH UPPER 70S TO LOW 80S SATURDAY.
SUNDAY-SUNDAY NIGHT...DRY WEATHER EXPECTED. MID AND HIGH CLOUDS
INCREASE FROM THE SOUTHWEST...ESPECIALLY LATE IN THE AFTERNOON
THROUGH THE NIGHT...AHEAD OF AN UPPER LEVEL LOW PRESSURE AREA MOVING
NORTHEAST TOWARD THE SLC AREA. HIGHS IN THE MID TO UPPER 70S WITH
LOWS IN THE LOW TO MID 50S. WILL BE INTRODUCING SOME SLIGHT CHANCE
TO LOW CHANCE POPS FOR SHOWERS/ISOLATED THUNDERSTORMS FOR THE
WESTERN 1/2 OF THE AREA. HIGH TEMPERATURES MID 70S TO AROUND 80 WITH
LOWS IN THE LOW TO MID 50S.
MONDAY-MONDAY NIGHT...SCATTERED TO BROKEN CLOUDINESS CONTINUES AS
THE UPPER LOW AND ASSOCIATED TROUGH LIFTS NORTHEAST TOWARD EASTERN
WYOMING. WILL NEED TO MAINTAIN SOME LOW CHANCES FOR
SHOWERS/THUNDERSTORMS. HIGHS IN THE LOW TO MID 70S WITH LOWS IN THE
LOW TO MID 50S.
TUESDAY-WEDNESDAY...UPPER LOW AND ASSOCIATED TROUGH FORECAST TO MOVE
EAST/SOUTHEAST TOWARD NORTHEAST NEBRASKA BY THE END OF THE PERIOD.
CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY SLOWLY DECREASING IN
COVERAGE FROM WEST TO EAST WEDNESDAY AS MOISTURE DECREASES FROM WEST
TO EAST WITH PASSAGE OF UPPER TROUGH. HIGHS TUESDAY IN THE LOW 70S
WITH LOW TO MID 70S WEDNESDAY. LOWS TUESDAY NIGHT IN THE LOW TO MID
50S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 539 PM MDT WED SEP 17 2014
VFR TO LIFR CONDITIONS FORECAST FOR THE 0Z TAFS. CURRENT AREA OF
STORMS SHOULD DECLINE IN THE NEXT HOUR OR TWO. A SECOND ROUND OF
STORMS SHOULD DEVELOP OVER THE NORTHEAST PART OF THE AREA NEAR THE
KMCK SITE OVERNIGHT. AT THIS TIME DO NOT HAVE THE CONFIDENCE TO
PLACE VCTS IN THE TAF. WILL SEE WHAT THE LATEST DATA SAYS THIS
EVENING. THE MAIN ISSUE WILL BE FOG/LOW STRATUS TONIGHT AND THUR.
MORNING FOR KMCK. BASED ON WHAT HAPPENED THIS MORNING...AND SINCE
MODELS ARE SHOWING THE SAME SETUP FOR TONIGHT...AM CONFIDENT
CONDITIONS WILL DETERIORATE. THE MAIN QUESTION IS HOW QUICKLY THE
CONDITIONS WILL DEGRADE. PREVIOUS FORECAST LOOKED GOOD SO ONLY
MADE SOME MINOR ADJUSTMENTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...99
AVIATION...JTL
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
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 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...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 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 SHREVEPORT LA
900 PM CDT WED SEP 17 2014
.DISCUSSION...
LOCAL AND REGIONAL RADARS CONTINUE TO SHOW A WELL DEFINED
DISTURBANCE ACROSS EAST CENTRAL OKLAHOMA INTO WEST CENTRAL
ARKANSAS MOVING SOUTH SOUTHWEST IN WEAK NW FLOW ALOFT. THIS
CLUSTER OF STRONG/SEVERE THUNDERSTORMS HAS DEVELOPED A COLD POOL
WHICH IS HELPING TO INITIATE AND SUSTAIN THE CONVECTION EVEN AFTER
SUNSET. LATEST MESOANALYSIS SHOWS CAPE NEAR 2000 J/KG IN OUR
VICINITY OF SE OK INTO SW AR WHICH SUGGESTS THAT THE CONVECTION
SHOULD CONTINUE TO COME SOUTH AT LEAST INTO OUR FAR NW ZONES LATER
THIS EVENING. LATEST HRRR SUPPORTS THIS SCENARIO WITH THE
CONVECTION WEAKENING QUICKLY JUST BEFORE IT MAKE IT TO TXK. FOR
THIS REASON...HAVE RAISED POPS TO CHANCE CATEGORY ACROSS OUR NW
ZONES THIS EVENING.
ELSEWHERE...CONVECTION IS MORE ISOLATED IN NATURE ACROSS NE TX
DESPITE INCREASING MOISTURE ACROSS OUR SW ZONES. PWATS NEAR 2
INCHES EXIST MAINLY TO THE WEST OF A LINE FROM TYR TO THE LOWER
TOLEDO BEND RESERVOIR AND THIS IS WHERE WE WILL CONTINUE TO
ADVERTISE LOW END CHANCE POPS OVERNIGHT. CONVECTION ACROSS CENTRAL
TEXAS ATTM SHOWING NO TENDENCY TO WANT TO MOVE TOWARDS OUR REGION
FROM THE WEST SO LOW END CHANCE POPS ACROSS THIS REGION SHOULD
SUFFICE.
DEWPOINT TEMPERATURES ARE QUITE A FEW DEGREES HIGHER TONIGHT
COMPARED TO 24 HOURS AGO GIVEN AND GIVEN THE INCREASING MOISTURE
FROM THE SOUTHWEST...THIS WILL LIKELY HAVE AN EFFECT ON OUR
TEMPERATURES ACROSS A FEW LOCATIONS. BUMPED OVERNIGHT LOWS UP
ACROSS OUR EASTERN MOST ZONES MAINLY. ELSEWHERE...LOWER 70S SHOULD
SUFFICE EXCEPT FOR UPPER 60S ACROSS OUR EXTREME NW ZONES WHERE
CONVECTION COULD ALLOW TEMPERATURES TO FALL BELOW 70 DEGREES.
OTHERWISE...ALL OTHER FORECAST PARAMETERS ARE IN PRETTY GOOD SHAPE
WITH NO OTHER CHANGES NECESSARY ATTM.
13
&&
.PREV DISCUSSION... /ISSUED 651 PM CDT WED SEP 17 2014/
AVIATION...
FOR THE 18/00Z TAFS...ISOLD TO WIDELY SCT CONVECTION WILL PERSIST
FOR THE FIRST FEW HRS OF THE TAF PERIOD BEFORE GRADUALLY
DISSIPATING DURING THE EVENING HRS. MOIST LVL AIRMASS AND A
LINGERING FRONTAL BOUNDARY WILL LIKELY LEAD TO ANOTHER ROUND OF
MVFR/IFR CIGS/VSBYS BEGINNING EARLY THURSDAY MORNING AND LINGERING
THROUGH THE MID TO LATE MORNING HRS. VFR CONDITIONS SHOULD PERSIST
BEYOND 18/16Z WITH ABUNDANT MID/HIGH LVL CLOUDS AND DAYTIME CU
BETWEEN 3500 AND 5000 FEET. ANOTHER ROUND OF SHWRS/TSTMS IS LIKELY
ACROSS MUCH OF THE AREA DURING THE DAY THURSDAY. /09/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 90 68 92 70 / 20 20 10 10 10
MLU 71 92 67 92 68 / 20 20 10 10 10
DEQ 69 88 66 88 67 / 40 30 10 10 10
TXK 72 88 67 89 69 / 20 20 10 10 10
ELD 70 89 67 89 67 / 20 30 10 10 10
TYR 72 87 68 89 70 / 30 40 20 10 10
GGG 72 88 67 90 69 / 30 30 20 10 10
LFK 73 86 69 91 70 / 30 50 20 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13
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
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 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 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...UPDATED
NWS ST LOUIS MO
707 PM CDT Wed Sep 17 2014
.UPDATE:
Issued at 659 PM CDT Wed Sep 17 2014
Noticed some light returns on radar which looked a lot like
drizzle. Sure enough, light drizzle is now occurring here in Weldon
Spring. Looking at NAM X-sections and RAP soundings, seeing a
fairly deep layer of low level moisture between the surface and
about 800mb coincident with weak lift centered around 850mb.
This lift continues though at least 03Z, ending between 04Z-06Z.
Have therefore gone ahead and added patchy drizzle to the forecast
for this evening for most areas east of Columbia and south of
Bowling Green MO/Pittsfield IL.
Carney
&&
.SHORT TERM: (Through Late Tonight)
Issued at 311 PM CDT Wed Sep 17 2014
Old peripheral upper level energy from the MCS that is now pushing
into northern AR will continue to generate isolated-scattered
showers into the early evening before it either weakens too much to
generate anything or it exits our area to the east.
Otherwise, a warm frontal boundary over southeast KS and extreme
southwest MO, which has been nearly stationary due to the MCS rain,
will try to move northeast later tonight and should generate a new
round of SHRA/TSRA over areas mainly to the south and west of STL
metro. Thunder chances up our way look meager enough to leave out
for now.
Clouds are starting to break in southwest IL now and this trend
should continue and even quicken as the upper level energy
generating the showers there comes to an end or exits. This will
leave the leftover low cloud mainly to the west of the MS river and
the light easterly flow will begin to erode the eastern edge of
this, albeit slowly, this evening. By late tonight, though, a
favorable fog/stratus setup along the periphery of the surviving low
cloud in central-southeast MO may actually allow the leftovers to
grow a bit back to the east again.
Went with a more aggressive cooling on the IL side of the river
tonight due to expected clearing, while preferred the warmer MOS in
central MO. In-between, tended to favor the cooler MOS guidance as
well.
TES
.LONG TERM: (Thursday through Next Wednesday)
Issued at 311 PM CDT Wed Sep 17 2014
Surface ridge to continue building in on Thursday. Could see some
lingering light showers over far southern portions of forecast area
in the morning. Otherwise, clouds to clear out from northeast to
southwest with highs in the low 70s. Lows Thursday night will be in
the 50s.
By Friday, surface ridge moves off to the east allowing warmer
southerly flow to return to the region. However, next weather system
to move in on Saturday with showers and thunderstorms possible and
persist through Saturday night before tapering off on Sunday. Highs
on Friday will be in the mid to upper 70s, in the low to mid 80s on
Saturday, then begin to cool back down on Sunday as next ridge of
high pressure builds in.
Cooler weather to persist through the middle of next week with highs
in the 70s and lows in the 40s and 50s.
Byrd
&&
.AVIATION: (For the 00z TAFs through 00z Thursday Evening)
Issued at 634 PM CDT Wed Sep 17 2014
A large area of stratus currently covers much of the region from
central IL through the St. Louis and Columbia areas into western
MO. Within this stratus, the cig heights are quite variable
ranging from low-end VFR in the eastern portion over IL to a mix
of MVFR and IFR in central MO. The low level flow within the
lowest 4000 ft veers significantly with east-southeast winds in
the lowest 1000 ft and westerly winds at 4000 ft. This makes the
forecast of cigs heights challenging. The St. Louis area could see
cig heights range from high-end MVFR to low-end VFR much of the
night, but late overnight the easterly flow deepens suggesting an
improving trend with some fog development. Conditions at KCOU
could vary some as well this evening from IFR to low-end MVFR,
however I think the general trend overnight will be for IFR
conditions and fog. All terminals should see improvement mid-late
Thursday morning.
Specifics for KSTL:
Cig heights may range from high-end MVFR to low-end VFR much of
the night but after 09z or so, easterly flow deepens suggesting
an improving trend with some fog development. VFR conditions should
previal by 14-15z and persist through the day on Thursday.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
649 PM CDT Wed Sep 17 2014
...Mesoscale Discussion and Updated Aviation Section...
.MESOSCALE DISCUSSION...
Issued at 649 PM CDT WED SEP 17 2014
Convection continues to propagate southwestward with time with
nearly all activity across northeastern Oklahoma and northwestern
Arkansas. Aside from a few lingering storms across far
southwestern Missouri, most locations will likely be dry for most
if not all of the evening.
Concerns are two fold for after midnight. First, will we see
redevelopment of showers and storms over northwestern Kansas and
second, the potential for fog development.
Recent runs of the HRRR have been handling ongoing activity fairly
well. These runs indicate another batch of storms developing over
northwestern Kansas later this evening and then riding a low level
boundary southeast toward the area. MUCAPE looks best to our
southwest, and this is likely where the bulk of any activity that
does develop will move. Unlike last night, the low level jet
tonight does not look nearly as impressive. In fact it is rather
ill defined, giving credence to any complex of storms propagating
closer to where the better instability will reside. That said, we
still cannot rule out a complex of storms clipping the
southwestern portion of the outlook area later tonight into
Thursday morning. It should be noted that several convection-
allowing short term models do not develop any activity. The 18z
NAM is by far an outlier and initialized quite poorly. As a
result, this model is discounted.
As far as fog potential is concerned, this is a conditional risk
based on whether or not we see an additional complex of storms, or
at least high level "blow off" clouds from a complex just to our
west. LAMP and MOS are insistent in developing fog across much of
the area. If we can clear out, certainly areas where rain fell
today will be prone to fog development. In addition, it appears
cross over temperatures will be exceeded across central Missouri.
This strongly suggests fog development if skies can remain clear.
Will continue to monitor observations and incoming near term model
runs to refine the risks of both the fog and rain chances.
&&
.SHORT TERM...(This Evening through Thursday)
Issued at 229 PM CDT WED SEP 17 2014
Well its been a little more active than previously thought. Models
did not handle today`s situation very well and confidence in
tonight`s forecast is low.
A frontal boundary is currently stalled from roughly near
Lamar to Roaring River State Park. West of that boundary
temperatures are in the middle 80s and over the eastern Missouri
Ozarks...temperatures were in the 60s. Convection continues to
regenerate near that boundary and has shown signs of moving slowly
westward.
The short term models are in a bit of a disagreement on the next
12 hours. But the over all trend was to move the axis of
convection slowly westward this evening. Temperatures will be
again tricky tonight through tomorrow. One note to add is there is
another very subtle mid level wave on the Water Vapor imagery over
western Nebraska that is riding southeastward it the mid level flow.
The big question mark is how this will interact with the boundary
in the area overnight and if there will be a similar repeat of
overnight convection developing late tonight through early
tomorrow morning. Will maintain highest chances for additional
convection over portions of southeast Kansas and far southwestern
Missouri for the rest of the evening and tonight.
Even though we have seen some heavy rainfall in the Springfield
area from earlier convection...no headlines for any flash flood
watches because the new development tonight should be southwest of
where the heavy rainfall fell today. There will still be a chance
for an isolated strong storm or two through tonight with marginal
severe hail and wind gusts up to 50 mph with the strongest
convection.
Will have the chance of rain diminishing through out the day on
Thursday as upper level ridging begins to move in and cut off rain
chances. Temperatures will be warmest out west tomorrow...low 80s
and coolest out east...low 70s
.LONG TERM...(Thursday Night through Wednesday)
Issued at 229 PM CDT WED SEP 17 2014
Warm and dry weather with high pressure in the upper levels on
Friday and for most of the day on Saturday. A front will move in
late afternoon and overnight Saturday to bring additional showers
and thunderstorms. Look at the upper level flow and the leftover
moisture from the tropical system out in the southwest U.S...looks
like that will mainly stay southwest of our area and most of the
energy with the trough will stay up in the Great Lakes Region over
the weekend. Will continue to maintain the chance for rain this
weekend but not expecting anything heavy at this time.
The front clears through on Sunday with gradual clearing and
drying. A Canadian airmass moves in for early next week with
seasonable Fall like weather.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 649 PM CDT WED SEP 17 2014
Very complicated forecast for tonight. There is a conditional risk
for fog at all sites, especially SGF/BBG where heavy rain fell
today. There are also signals for another complex of storms to
clip the area late tonight. If these storms do materialize, fog
will be a lesser risk. If we can stay clear, fog will be a much
greater risk. Much will depend on the evolution of mesoscale (and
finer) details in the next few hours. Will utilize amendments to
change course if/when needed. If fog is the winner tonight and
storms do not materialize, LIFR conditions are possible, gradually
improving during the daylight hours of Thursday morning. VFR is
expected Thursday afternoon.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Gagan
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Gagan
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 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 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 WILMINGTON NC
1055 PM EDT WED SEP 17 2014
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH
PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK. THE NEXT
COLD FRONT WILL MOVE THROUGH ON TUESDAY FOLLOWED BY COOL AND DRY
HIGH PRESSURE THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM WEDNESDAY...ISOLATED CONVECTION HAS CONTINUED ACROSS
ROBESON COUNTY AND ALSO JUST OFF THE NEW HANOVER COUNTY BEACHES THIS
EVENING. WITH SURFACE TEMPERATURES NOW 70-74 DEGREES IN MOST
LOCATIONS SURFACE-BASED CAPE IS BELOW 1000 J/KG WITH 20-40 J/KG OF
CONVECTIVE INHIBITION TO DEAL WITH. HOWEVER LIFTING PARCELS FROM 925
MB GIVES ABOUT THE SAME INSTABILITY WITH NO SIGNIFICANT CAPPING.
THIS IS LIKELY THE SOURCE REGION FOR THE ONGOING SHOWERS AND
THUNDERSTORMS. ACTIVITY APPEARS TO BE FOCUSED ALONG AN INVERTED
TROUGH THAT IS THE LEADING EDGE OF A MODEST NORTHEASTERLY SURGE OVER
EASTERN NORTH CAROLINA. GIVEN THE VERY MOIST AIRMASS UP THROUGH 850
MB THERE IS NO REASON THIS INVERTED TROUGH/SURGE LINE CANNOT SERVE
AS THE FOCUS FOR ADDITIONAL SHOWERS OR THUNDERSTORMS ALL THE WAY
THROUGH THE NIGHT AS IT MOVES SOUTHWESTWARD THROUGH EASTERN SOUTH
CAROLINA. IN AGREEMENT WITH THE LATEST HRRR (NCEP PARALLEL VERSION)
WILL MAINTAIN 20-30 POPS ACROSS MOST OF EASTERN SOUTH CAROLINA
THROUGH THE NIGHT. THIS MAY HAVE SOME NEGATIVE IMPACT ON THE
DEVELOPMENT OF FOG AND LOW STRATUS LATE TONIGHT...BUT NO SIGNIFICANT
CHANGES WERE MADE TO THAT PORTION OF THE FORECAST. PREVIOUS
DISCUSSION FROM 730 PM FOLLOWS...
CHANGES TO THE FORECAST EARLY THIS EVENING CENTER ON OBSERVED RADAR
TRENDS. CONVECTION IS FINALLY DIMINISHING IN INTENSITY AND COVERAGE
ACROSS THE CAPE FEAR AREA...BUT A RENEWED CLUSTER OF STORMS IS
CROSSING THE SANTEE RIVER WITH ITS SIGHTS SET ON GEORGETOWN IN THE
NEXT HOUR. STORM MOTION IS BEING DRIVEN PRIMARILY BY BOUNDARIES AND
COLD POOL INTERACTIONS...ALTHOUGH A TREND NOTED WITH THE TALLER MORE
SIGNIFICANT THUNDERSTORMS HAS BEEN TO ACCELERATE EASTWARD DUE TO
STRONG WEST WINDS UP ABOVE 600 MB THAT THE SHALLOWER LESS
SIGNIFICANT CONVECTION ISN`T BEING AFFECTED BY. THE SPC MESOANALYSIS
PAGE SHOWS SURFACE-BASED CAPE IS AROUND 1500 J/KG WITH FAVORABLE
MID-LEVEL LAPSE RATES AROUND 6 DEG C/KM.
CONVECTIVE TRENDS THIS EVENING SHOULD BE TOWARD A SLOW DECREASE IN
ACTIVITY AS THE SURFACE COOLS. PLENTY OF DRY AIR ABOVE 700 MB HAS
BEEN HELPING PRODUCE CONVECTIVE OUTFLOW BOUNDARIES DUE TO
ENTRAINMENT INTO DOWNDRAFTS. THE LATEST FEW HRRR RUNS SHOW THERE MAY
BE A FEW LINGERING SHOWERS ACROSS NE SOUTH CAROLINA ROOTED IN A
LAYER OF UNSTABLE AIR AT 950-925 MB PERSISTING AFTER MIDNIGHT. I`LL
KEEP SOME 20 POPS GOING FROM MYRTLE BEACH AND MARION SOUTHWARD
BETWEEN 03-06Z TO ACCOUNT FOR THIS POTENTIAL.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO OTHER FORECAST ELEMENTS.
LOWS SHOULD STILL FALL INTO THE LOWER TO MID 60S FOR MOST AREAS AS
WEAK COOL ADVECTION DEVELOPS OVERNIGHT ON LIGHT NE WINDS BELOW 850
MB. LINGERING LOW-LEVEL MOISTURE WILL ALMOST CERTAINLY CREATE LOW
STRATUS AND FOG LATE TONIGHT...ESPECIALLY INLAND FROM THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE BUILDING DOWN INTO THE
CAROLINAS FROM THE GREAT LAKES ON THURS WILL SHIFT EAST PRODUCING
A VERY PRONOUNCED WEDGE PATTERN BY FRI AFTN. AT THE SAME TIME THE
MID TO UPPER TROUGH OVER THE EAST COAST WILL LIFT OFF TO THE
NORTHEAST. BEFORE THE TROUGH LIFTS OFF...A COUPLE OF MINOR
PERTURBATIONS RIDING AROUND THE BASE MAY ENHANCE CLOUDS AND LOW
END PCP ON THURS...BUT NOT COUNTING ON MUCH. AS TROUGH LIFTS OFF
THROUGH FRI...IT MAY PROVIDE ENOUGH OF A WEAKNESS TO ALLOW
DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST TO RETROGRADE
BACK TO THE W-NW THROUGH FRI NIGHT. OVERALL EXPECT DECENT
NORTHEAST FLOW AS GRADIENT BECOMES MORE PINCHED AS TROUGH OF LOW
PRESSURE SHIFTS NORTH TOWARD THE SOUTHEAST COAST THROUGH LATE FRI
INTO FRI NIGHT. THE NAM HAS THE LOW MOVING FARTHER WEST WITH A
GREATER ON SHORE FLOW OF MOISTURE THROUGH FRI AND A MUCH WETTER
FORECAST...WHILE THE GFS/ECMWF CONFINE THE GREATEST MOISTURE OFF
SHORE AND JUST ALONG THE COAST. FOR NOW WILL GO WITH BRUNT OF CLOUDS
AND POPS OFF SHORE AND JUST ALONG THE COAST IN NE FLOW THROUGH
FRI NIGHT.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN. LOW TEMPERATURES WILL END UP A
LITTLE ABOVE CLIMO DUE TO CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...POTENTIALLY UNSETTLED TO START THE
PERIOD...BUT EVEN BY D4 THERE IS CONSIDERABLE MODEL SPREAD. STALLED
BOUNDARY OFFSHORE WILL BE A FOCUS FOR LOW PRESSURE DEVELOPMENT...BUT
THE QUESTION REMAINS HOW CLOSE TO THE COAST THIS LOW WILL FORM. THE
NAM/CMC ARE IN ONE CAMP WITH DEEP EASTERLY FLOW AHEAD OF A LOW
PRESSURE MOVING RIGHT ALONG THE COAST...CAUSING WIDESPREAD AND
POSSIBLY HEAVY...RAINFALL. THE GFS/ECMWF ARE FURTHER OFFSHORE...WITH
NE FLOW THROUGH THE WEEKEND AS THE LOW PRESSURE STAYS WELL OFF THE
COAST. WPC FAVORING THE ECMWF AND ITS ENSEMBLES...WHICH HAVE
FLUCTUATED LITTLE FROM LAST WEEK...AND THUS WILL CONTINUE WITH THE
INHERITED FORECAST LEANING SIGNIFICANTLY ON THE ECMWF WITH SOME
BLENDING WITH THE WETTER SOLUTIONS. THIS SUGGESTS AT LEAST
WIDESPREAD CLOUD COVER SATURDAY AS THE LOW PRESSURE MAKES ITS
CLOSEST APPROACH...WITH SHOWERS MOST LIKELY ACROSS THE EASTERN
ZONES. IMPROVEMENT WILL OCCUR ON SUNDAY AS THE LOW PRESSURE PULLS
OFF TO THE NORTHEAST...AND TEMPS WILL BE AROUND SEASONABLE THROUGH
THE WKND...ALTHOUGH SUNDAY WILL LIKELY BE A BIT WARMER.
A BRIEF PERIOD OF RETURN FLOW DEVELOPS AHEAD OF A STRONG COLD FRONT
WHICH IS SLATED TO CROSS TUESDAY AFTN. THIS BRINGS A DAY OR TWO OF
WARMER TEMPERATURES...BEFORE CANADIAN HIGH PRESSURE ENVELOPS THE
REGION FOR MID-WEEK. CONVECTION LOOKS LIKELY ON TUESDAY WITH THE
COLD FRONT...AND WILL BUMP POP TO CHC FOR TUESDAY AS SURFACE
CONVERGENCE...PVA...AND SOME JET-LEVEL DIFFLUENCE COMBINE IN A RICH
THETA-E AIR MASS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...CONVECTION ASSOCIATED WITH AN UPPER TROUGH MOVING
OVERHEAD IS WANING THIS EVENING. WILL MONITOR FOR ANY DEVELOPMENT
ALONG THE OUTFLOW BOUNDARY MOVING TOWARD KCRE/KMYR...BUT ATTM NO
STORMS POSE A THREAT TO ANY TAF SITE. FOG/STRATUS WILL BECOME AN
INCREASING CONCERN OVERNIGHT...ESPECIALLY INLAND AT KFLO/KLBT. THESE
SITES COULD SEE MVFR VSBYS BY 06Z...WITH IFR/LIFR CIGS/VSBYS
DEVELOPING IN THE PRE-DAWN HOURS BEGINNING AROUND 09Z. ALONG THE
COAST...NORTHEAST WINDS AOB 5 KT SHOULD KEEP VSBYS FROM DROPPING
BELOW MVFR LEVELS. BUT STILL EXPECT MVFR/TEMPO IFR CIGS TO DEVELOP
AT KILM/KCRE/KMYR BY DAYBREAK...THOUGH CONFIDENCE IS SLIGHTLY LOWER
THAN FOR THE INLAND TERMINALS. ANY LINGERING MVFR CIGS AFTER 13Z
SHOULD IMPROVE TO VFR BY MIDDAY. NORTHEAST WINDS AOB 10 KT WILL
PREVAIL ON THU...BECOMING MORE EAST IN THE AFTERNOON.
EXTENDED OUTLOOK...GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS COOL
HIGH PRESSURE EXTENDS SOUTHWARD INTO THE CAROLINAS. EARLY MORNING
MVFR/IFR STRATUS POSSIBLE SAT/SUN MORNING. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM WEDNESDAY...WINDS ACROSS THE COASTAL WATERS NORTH OF
CAPE FEAR ARE A LITTLE STRONGER THAN ANTICIPATED EARLIER. THIS IS
LIKELY DUE TO A TIGHTENING PRESSURE GRADIENT BEHIND A MODEST SURGE
LINE/INVERTED TROUGH THAT IS DROPPING SLOWLY SOUTHWESTWARD ALONG THE
COAST. WIND GUSTS UP TO 21 KNOTS HAVE BEEN MEASURED AT CAPE LOOKOUT
AND WRIGHTSVILLE BEACH WITHIN THE PAST HOUR. NO MODEL HAS WINDS THIS
STRONG CURRENTLY...BUT I HAVE BUMPED WIND SPEED FORECASTS UP TO A
SOLID 15 KNOTS NORTH OF CAPE FEAR...AND 10-15 KNOTS SOUTH OF CAPE
FEAR TO NEAR MYRTLE BEACH. SEAS ARE UP TO A SOLID 4 FEET NORTH OF
CAPE FEAR IN A COMBINATION OF SWELL AND WIND WAVES. PREVIOUS
DISCUSSION FROM 730 PM FOLLOWS...
WEAK LOW PRESSURE WELL OFF THE SC COAST WILL MAINTAIN A LIGHT NE
WIND OVERNIGHT. HIGH PRESSURE NORTH OF THE GREAT LAKES WILL BEGIN TO
RIDGE SOUTHWARD LATE TONIGHT. A SLIGHT NE SURGE TONIGHT WILL
INCREASE WIND SPEEDS UP TO 10 TO 15 KT. EASTERLY SWELL FROM DISTANT
HURRICANE EDOUARD WILL ALLOW SEAS TO BE CONSIDERABLY HIGHER THAN THE
WIND SPEEDS WOULD OTHERWISE INDICATE... 3 TO 4 FT OUTSIDE OF
SHOALING/NEARSHORE INFLUENCES...WITH DOMINANT PERIODS OF 12 TO 13
SECONDS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE RIDGING DOWN FROM THE NORTH
WILL PRODUCE LIGHT NORTHEAST FLOW ON THU AROUND 10 KTS OR LESS. WINDS
WILL WILL INCREASE SIGNIFICANTLY THROUGH FRI AS DISTINCT HIGH
PRESSURE WEDGE SETS UP AND LOW PRESSURE DEVELOPS OFF THE SOUTHEAST
COAST. NE WINDS WILL INCREASE UP TO 20 KT WITH HIGHER GUSTS THROUGH
FRI INTO FRI NIGHT AND MAY BECOME MORE EASTERLY DEPENDING ON
POSITION AND STRENGTH OF DEVELOPING LOW OFF THE SOUTHEAST COAST.
SEAS 2 TO 4 FT ON THURS WILL DIMINISH SLIGHTLY THROUGH THE DAY AS
LONG PERIOD SWELLS DECREASE. AS NE WINDS INCREASE THROUGH FRI...SEAS
MAY REACH SCA THRESHOLDS INTO FRI EVE...ESPECIALLY NORTH OF CAPE
FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT. MAINLY IN
OUTER WATERS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...CONCERN THROUGH THE EXTENDED INVOLVES A LOW
PRESSURE SYSTEM PROGGED TO DEVELOP ALONG A STALLED COLD FRONT OFF
THE COAST. STILL SIGNIFICANT UNCERTAINTY INTO THE STRENGTH AND EXACT
PLACEMENT OF THIS FEATURE...BUT AT LEAST SOME IMPACTS ARE EXPECTED
LOCALLY. THIS LOW PRESSURE WILL MAKES ITS CLOSEST APPROACH TO THE
WATERS ON SATURDAY...PRODUCING ENHANCED NE WINDS OF 15-20
KTS...POSSIBLY HIGHER IF THE LOW IS CLOSER/STRONGER THAN CURRENTLY
FORECAST. WINDS THEN BECOME VARIABLE ON SUNDAY AS A WEAK RIDGE OF
HIGH PRESSURE BUILDS TOWARDS THE AREA...BEFORE TURNING TO THE SW
WIND SW ON MONDAY...WITH SPEEDS RISING BACK TO 10-15 KTS. WAVES WILL
BE PRIMARILY NE-WIND-WAVE DRIVEN ON SATURDAY WITH HEIGHTS 4-5
FT...BUT AGAIN...IF THE SYSTEM IS STRONGER OR CLOSER AN SCA MAY BE
NEEDED. THEREAFTER...WAVE HEIGHTS FALL TO 2-4 FT ON SUNDAY...AND
THEN 1-3 ON MONDAY WITH A SW WIND WAVE AND WEAK SE SWELL FORMING IN
THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
717 PM EDT WED SEP 17 2014
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH
PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK. THE NEXT
COLD FRONT WILL MOVE THROUGH ON TUESDAY FOLLOWED BY COOL AND DRY
HIGH PRESSURE THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM WEDNESDAY...CHANGES TO THE FORECAST EARLY THIS EVENING
CENTER ON OBSERVED RADAR TRENDS. CONVECTION IS FINALLY DIMINISHING
IN INTENSITY AND COVERAGE ACROSS THE CAPE FEAR AREA...BUT A RENEWED
CLUSTER OF STORMS IS CROSSING THE SANTEE RIVER WITH ITS SIGHTS SET
ON GEORGETOWN IN THE NEXT HOUR. STORM MOTION IS BEING DRIVEN
PRIMARILY BY BOUNDARIES AND COLD POOL INTERACTIONS...ALTHOUGH A
TREND NOTED WITH THE TALLER MORE SIGNIFICANT THUNDERSTORMS HAS BEEN
TO ACCELERATE EASTWARD DUE TO STRONG WEST WINDS UP ABOVE 600 MB
THAT THE SHALLOWER LESS SIGNIFICANT CONVECTION ISN`T BEING AFFECTED
BY. THE SPC MESOANALYSIS PAGE SHOWS SURFACE-BASED CAPE IS AROUND
1500 J/KG WITH FAVORABLE MID-LEVEL LAPSE RATES AROUND 6 DEG C/KM.
CONVECTIVE TRENDS THIS EVENING SHOULD BE TOWARD A SLOW DECREASE IN
ACTIVITY AS THE SURFACE COOLS. PLENTY OF DRY AIR ABOVE 700 MB HAS
BEEN HELPING PRODUCE CONVECTIVE OUTFLOW BOUNDARIES DUE TO
ENTRAINMENT INTO DOWNDRAFTS. THE LATEST FEW HRRR RUNS SHOW THERE MAY
BE A FEW LINGERING SHOWERS ACROSS NE SOUTH CAROLINA ROOTED IN A
LAYER OF UNSTABLE AIR AT 950-925 MB PERSISTING AFTER MIDNIGHT. I`LL
KEEP SOME 20 POPS GOING FROM MYRTLE BEACH AND MARION SOUTHWARD
BETWEEN 03-06Z TO ACCOUNT FOR THIS POTENTIAL.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO OTHER FORECAST ELEMENTS.
LOWS SHOULD STILL FALL INTO THE LOWER TO MID 60S FOR MOST AREAS AS
WEAK COOL ADVECTION DEVELOPS OVERNIGHT ON LIGHT NE WINDS BELOW 850
MB. LINGERING LOW-LEVEL MOISTURE WILL ALMOST CERTAINLY CREATE LOW
STRATUS AND FOG LATE TONIGHT...ESPECIALLY INLAND FROM THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE BUILDING DOWN INTO THE
CAROLINAS FROM THE GREAT LAKES ON THURS WILL SHIFT EAST PRODUCING
A VERY PRONOUNCED WEDGE PATTERN BY FRI AFTN. AT THE SAME TIME THE
MID TO UPPER TROUGH OVER THE EAST COAST WILL LIFT OFF TO THE
NORTHEAST. BEFORE THE TROUGH LIFTS OFF...A COUPLE OF MINOR
PERTURBATIONS RIDING AROUND THE BASE MAY ENHANCE CLOUDS AND LOW
END PCP ON THURS...BUT NOT COUNTING ON MUCH. AS TROUGH LIFTS OFF
THROUGH FRI...IT MAY PROVIDE ENOUGH OF A WEAKNESS TO ALLOW
DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST TO RETROGRADE
BACK TO THE W-NW THROUGH FRI NIGHT. OVERALL EXPECT DECENT
NORTHEAST FLOW AS GRADIENT BECOMES MORE PINCHED AS TROUGH OF LOW
PRESSURE SHIFTS NORTH TOWARD THE SOUTHEAST COAST THROUGH LATE FRI
INTO FRI NIGHT. THE NAM HAS THE LOW MOVING FARTHER WEST WITH A
GREATER ON SHORE FLOW OF MOISTURE THROUGH FRI AND A MUCH WETTER
FORECAST...WHILE THE GFS/ECMWF CONFINE THE GREATEST MOISTURE OFF
SHORE AND JUST ALONG THE COAST. FOR NOW WILL GO WITH BRUNT OF CLOUDS
AND POPS OFF SHORE AND JUST ALONG THE COAST IN NE FLOW THROUGH
FRI NIGHT.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN. LOW TEMPERATURES WILL END UP A
LITTLE ABOVE CLIMO DUE TO CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...POTENTIALLY UNSETTLED TO START THE
PERIOD...BUT EVEN BY D4 THERE IS CONSIDERABLE MODEL SPREAD. STALLED
BOUNDARY OFFSHORE WILL BE A FOCUS FOR LOW PRESSURE DEVELOPMENT...BUT
THE QUESTION REMAINS HOW CLOSE TO THE COAST THIS LOW WILL FORM. THE
NAM/CMC ARE IN ONE CAMP WITH DEEP EASTERLY FLOW AHEAD OF A LOW
PRESSURE MOVING RIGHT ALONG THE COAST...CAUSING WIDESPREAD AND
POSSIBLY HEAVY...RAINFALL. THE GFS/ECMWF ARE FURTHER OFFSHORE...WITH
NE FLOW THROUGH THE WEEKEND AS THE LOW PRESSURE STAYS WELL OFF THE
COAST. WPC FAVORING THE ECMWF AND ITS ENSEMBLES...WHICH HAVE
FLUCTUATED LITTLE FROM LAST WEEK...AND THUS WILL CONTINUE WITH THE
INHERITED FORECAST LEANING SIGNIFICANTLY ON THE ECMWF WITH SOME
BLENDING WITH THE WETTER SOLUTIONS. THIS SUGGESTS AT LEAST
WIDESPREAD CLOUD COVER SATURDAY AS THE LOW PRESSURE MAKES ITS
CLOSEST APPROACH...WITH SHOWERS MOST LIKELY ACROSS THE EASTERN
ZONES. IMPROVEMENT WILL OCCUR ON SUNDAY AS THE LOW PRESSURE PULLS
OFF TO THE NORTHEAST...AND TEMPS WILL BE AROUND SEASONABLE THROUGH
THE WKND...ALTHOUGH SUNDAY WILL LIKELY BE A BIT WARMER.
A BRIEF PERIOD OF RETURN FLOW DEVELOPS AHEAD OF A STRONG COLD FRONT
WHICH IS SLATED TO CROSS TUESDAY AFTN. THIS BRINGS A DAY OR TWO OF
WARMER TEMPERATURES...BEFORE CANADIAN HIGH PRESSURE ENVELOPS THE
REGION FOR MID-WEEK. CONVECTION LOOKS LIKELY ON TUESDAY WITH THE
COLD FRONT...AND WILL BUMP POP TO CHC FOR TUESDAY AS SURFACE
CONVERGENCE...PVA...AND SOME JET-LEVEL DIFFLUENCE COMBINE IN A RICH
THETA-E AIR MASS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...CONVECTION ASSOCIATED WITH AN UPPER TROUGH MOVING
OVERHEAD IS WANING THIS EVENING. WILL MONITOR FOR ANY DEVELOPMENT
ALONG THE OUTFLOW BOUNDARY MOVING TOWARD KCRE/KMYR...BUT ATTM NO
STORMS POSE A THREAT TO ANY TAF SITE. FOG/STRATUS WILL BECOME AN
INCREASING CONCERN OVERNIGHT...ESPECIALLY INLAND AT KFLO/KLBT. THESE
SITES COULD SEE MVFR VSBYS BY 06Z...WITH IFR/LIFR CIGS/VSBYS
DEVELOPING IN THE PRE-DAWN HOURS BEGINNING AROUND 09Z. ALONG THE
COAST...NORTHEAST WINDS AOB 5 KT SHOULD KEEP VSBYS FROM DROPPING
BELOW MVFR LEVELS. BUT STILL EXPECT MVFR/TEMPO IFR CIGS TO DEVELOP
AT KILM/KCRE/KMYR BY DAYBREAK...THOUGH CONFIDENCE IS SLIGHTLY LOWER
THAN FOR THE INLAND TERMINALS. ANY LINGERING MVFR CIGS AFTER 13Z
SHOULD IMPROVE TO VFR BY MIDDAY. NORTHEAST WINDS AOB 10 KT WILL
PREVAIL ON THU...BECOMING MORE EAST IN THE AFTERNOON.
EXTENDED OUTLOOK...GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS COOL
HIGH PRESSURE EXTENDS SOUTHWARD INTO THE CAROLINAS. EARLY MORNING
MVFR/IFR STRATUS POSSIBLE SAT/SUN MORNING. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM WEDNESDAY...WEAK LOW PRESSURE WELL OFF THE SC COAST
WILL MAINTAIN A LIGHT NE WIND OVERNIGHT. HIGH PRESSURE NORTH OF THE
GREAT LAKES WILL BEGIN TO RIDGE SOUTHWARD LATE TONIGHT. A SLIGHT NE
SURGE TONIGHT WILL INCREASE WIND SPEEDS UP TO 10 TO 15 KT. EASTERLY
SWELL FROM DISTANT HURRICANE EDOUARD WILL ALLOW SEAS TO BE
CONSIDERABLY HIGHER THAN THE WIND SPEEDS WOULD OTHERWISE INDICATE...
3 TO 4 FT OUTSIDE OF SHOALING/NEARSHORE INFLUENCES...WITH DOMINANT
PERIODS OF 12 TO 13 SECONDS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE RIDGING DOWN FROM THE NORTH
WILL PRODUCE LIGHT NORTHEAST FLOW ON THU AROUND 10 KTS OR LESS. WINDS
WILL WILL INCREASE SIGNIFICANTLY THROUGH FRI AS DISTINCT HIGH
PRESSURE WEDGE SETS UP AND LOW PRESSURE DEVELOPS OFF THE SOUTHEAST
COAST. NE WINDS WILL INCREASE UP TO 20 KT WITH HIGHER GUSTS THROUGH
FRI INTO FRI NIGHT AND MAY BECOME MORE EASTERLY DEPENDING ON
POSITION AND STRENGTH OF DEVELOPING LOW OFF THE SOUTHEAST COAST.
SEAS 2 TO 4 FT ON THURS WILL DIMINISH SLIGHTLY THROUGH THE DAY AS
LONG PERIOD SWELLS DECREASE. AS NE WINDS INCREASE THROUGH FRI...SEAS
MAY REACH SCA THRESHOLDS INTO FRI EVE...ESPECIALLY NORTH OF CAPE
FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT. MAINLY IN
OUTER WATERS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...CONCERN THROUGH THE EXTENDED INVOLVES A LOW
PRESSURE SYSTEM PROGGED TO DEVELOP ALONG A STALLED COLD FRONT OFF
THE COAST. STILL SIGNIFICANT UNCERTAINTY INTO THE STRENGTH AND EXACT
PLACEMENT OF THIS FEATURE...BUT AT LEAST SOME IMPACTS ARE EXPECTED
LOCALLY. THIS LOW PRESSURE WILL MAKES ITS CLOSEST APPROACH TO THE
WATERS ON SATURDAY...PRODUCING ENHANCED NE WINDS OF 15-20
KTS...POSSIBLY HIGHER IF THE LOW IS CLOSER/STRONGER THAN CURRENTLY
FORECAST. WINDS THEN BECOME VARIABLE ON SUNDAY AS A WEAK RIDGE OF
HIGH PRESSURE BUILDS TOWARDS THE AREA...BEFORE TURNING TO THE SW
WIND SW ON MONDAY...WITH SPEEDS RISING BACK TO 10-15 KTS. WAVES WILL
BE PRIMARILY NE-WIND-WAVE DRIVEN ON SATURDAY WITH HEIGHTS 4-5
FT...BUT AGAIN...IF THE SYSTEM IS STRONGER OR CLOSER AN SCA MAY BE
NEEDED. THEREAFTER...WAVE HEIGHTS FALL TO 2-4 FT ON SUNDAY...AND
THEN 1-3 ON MONDAY WITH A SW WIND WAVE AND WEAK SE SWELL FORMING IN
THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...BJR
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 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 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 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 NORMAN OK
936 PM CDT WED SEP 17 2014
.DISCUSSION...
WILL CONTINUE WITH LOW POPS MAINLY SOUTH OVERNIGHT WITH WEAK
IMPULSE MOVING OUT OF W TX. LATER HRRR RUNS HAVE BACKED OFF ON
ACTIVITY MOVING FROM KS INTO NRN OK OVERNIGHT...BUT WITH
SHOWERS/TSTMS STILL LINGERING IN ERN OK AND SFC BOUNDARY IN THE
AREA WILL ALSO LEAVE LOW POPS MAINLY E OF I-35.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 90 69 88 / 10 30 10 10
HOBART OK 71 91 69 88 / 10 30 10 20
WICHITA FALLS TX 72 91 70 89 / 20 30 20 20
GAGE OK 64 90 66 87 / 0 10 10 20
PONCA CITY OK 70 89 69 89 / 10 20 10 10
DURANT OK 72 89 69 88 / 20 30 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
02/84
AREA FORECAST DISCUSSION
NWS NORMAN OK
1146 PM CDT MON SEP 15 2014
.AVIATION...
A COLD FRONT CONTINUES TO SLOWLY MOVE SOUTHWARD OVERNIGHT. WINDS
HAVE SHIFTED TO THE NORTH FROM KGAG/KWWR TO KPNC. EXPECT WINDS TO
SHIFT TO THE NORTH AT ALL TERMINALS BY 12Z TUES. WHAT REMAINS
UNCLEAR IS THE POTENTIAL FOR LOW STRATUS TO DEVELOP IN THE POST
FRONTAL AIR. SO FAR...LOW CLOUDS HAVE BEEN VERY SLOW TO BUILD INTO
NORTHERN/WESTERN OKLAHOMA IN THE WAKE OF THE FRONT.
HOWEVER...GUIDANCE AND HIGH RES MODELS CONTINUE TO SUGGEST
MVFR/IFR CIGS WILL BECOME MORE PREVALENT FROM 09Z TO 14Z AT NEARLY
ALL TERMINALS. WHILE A SPOTTY SHOWER OR TWO MAY AFFECT TAF SITES
FROM I-40 SOUTHWARD...GREATER CHANCES FOR SHRA/TSRA WILL REMAIN
OVER WESTERN NORTH TEXAS...AND WILL MAINTAIN PROB30 GROUP OF ISOLD
TSRA. WINDS WILL GRADUALLY SHIFT BACK TO THE SOUTH BY 18Z...WITH
LOW CIGS GRADUALLY CLEARING.
&&
.PREV DISCUSSION... /ISSUED 851 PM CDT MON SEP 15 2014/
UPDATE...
HAVE MADE SOME MINOR CHANGES TO THE GRIDS FOR TONIGHT. BASED ON
LATEST COUPLE OF RUNS OF THE HRRR WILL KEEP LOWER END CHANCE POPS
ACROSS PORTIONS OF CENTRAL INTO SOUTHEAST OKLAHOMA THIS EVENING
AND THEN A BIT HIGHER ACROSS SOUTHERN OK INTO NORTH TEXAS LATE
TONIGHT AS SFC FRONT WORKS SOUTH TOWARD THE RED RIVER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 64 82 66 87 / 30 20 10 20
HOBART OK 65 85 67 89 / 20 20 10 10
WICHITA FALLS TX 68 86 69 89 / 30 40 10 20
GAGE OK 59 83 64 90 / 20 10 10 10
PONCA CITY OK 61 79 63 86 / 20 10 20 30
DURANT OK 68 87 69 88 / 30 30 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/84
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
917 PM EDT WED SEP 17 2014
.SYNOPSIS...
A TROUGH OF LOW PRESSURE OVER EASTERN NORTH AMERICA WILL SLOWLY
WEAKEN INTO SATURDAY BEFORE RE-INTENSIFYING LATER ON SUNDAY ONCE
AGAIN. OVERALL IT SHOULD BE A RELATIVELY COOL AND DRY PERIOD WITH
A BRIEF WARM UP OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
MUCH OF THE DIURNAL CUMULUS HAS DISSIPATED...BUT BUT STILL SEEING
SCATTERED STRATOCU FROM THE LAUREL HIGHLANDS THROUGH THE CENTRAL
MOUNTAINS LATE THIS EVENING. THIS MAINTENANCE IS BEING
ACCOMPLISHED BY A WEAK SHORTWAVE OVER THE LAUREL HIGHLANDS THIS
EVENING WHICH WILL TRACK ACROSS THE SOUTHERN TIER AND OFF THE
SOUTH NJ COAST BY 12Z THU.
HIGH CLOUDS ASSOCIATED WITH A MORE IMPORTANT UPPER TROF DROPPING
THROUGH THE CENTRAL GLAKS WILL APPROACH THE NORTHWEST MOUNTAINS
TOWARDS DAWN. PATCHY VALLEY FOG WILL BE THE ONLY SENSIBLE WEATHER
OVERNIGHT. MIN TEMPS WILL STILL BE ON THE COOL SIDE...RANGING
FROM THE LOWER TO MIDDLE 40S OVER THE NORTHERN TWO THIRDS OF
CENTRAL PA...TO THE LOWER 50S ACROSS THE SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
ANOTHER DRY AND SEASONABLY COOL DAY. A WEAK FRONTAL BOUNDARY WILL
MOVE ACROSS THE REGION BRINGING SLIGHTLY COOLER AIR AND JUST
SCATTERED CLOUD COVER. THURSDAY NIGHT WILL BY QUITE COLD WITH
FROST POSSIBLE ACROSS THE COLDEST VALLEYS...AND A FROST ADVISORY
MAY HAVE TO BE ISSUED FOR PORTIONS OF WESTERN PA FOR FRIDAY
MORNING ON THURSDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WARMER AIR AND HIGHER MOISTURE WILL ADVECT INTO THE REGION THIS
WEEKEND ON INCREASING SW FLOW AROUND A HIGH PRESSURE AREA
/RETREATING TO THE EAST/. AT THE SAME TIME...TROUGH BEGINS TO
CARVE INTO ZONAL FLOW OVER THE GREAT LAKES AS A SYSTEM APPROACHES
PA FOR SUN/MON. THE RESULT WILL BE A PAIR OF ABOVE NORMAL
TEMPERATURE DAYS SAT-SUN WITH TEMPS MAINLY IN THE 70S...AND TAKING
A RUN AT 80F IN THE SE. WE/LL ALSO GET A BREAK FROM OUR RUN OF
CHILLY OVERNIGHTS AS LOWS REMAIN WELL INTO THE 40S AND 50S. SHOWER
ACTIVITY SHOULD REMAIN CONFINED TO THE UPPER MIDWEST THROUGH EARLY
SUNDAY.
THE CENTER OF THE APPROACHING LOW PRESSURE SYSTEM WILL REMAIN WELL
TO OUR NORTH...BUT A WEAK COLD FRONT WILL PUSH THROUGH PA SUNDAY
INTO SUN NIGHT. THIS WILL BE THE BEST CHANCE OF RAIN/SHOWERS
THROUGH DURATION OF THE EXTENDED FORECAST. THE LATEST ECMWF IS THE
WETTEST WITH QPF POTENTIALLY UP TO 0.25...WHILE THE GFS BRINGS
LIGHTER AMOUNTS.
THE 500 HPA TROUGH BEHIND THE FRONT DEEPENS OVER THE REGION MONDAY
INTO TUESDAY. THIS WILL KEEP MENTION FOR SCT INSTABILITY SHOWERS
MONDAY INTO TUESDAY...MAINLY IN HIGHER TERRAIN OF N/W CWA. COOLER
AIR ON NW FLOW WILL GRADUALLY FILTER BACK INTO THE REGION...WITH
MONDAY/S HIGHS ABOUT 8-10F COOLER AND TUESDAY FALLING ANOTHER 5F
OR SO. OVERNIGHT LOWS WILL SLIP BACK INTO THE 40S MON NIGHT...WITH
SOME MID/UPPER 30S POSS IN THE NORTHERN MTNS TUE NIGHT.
TROUGH LIFTS TO THE NE BY MIDWEEK AS HIGH PRESSURE SETTLES BACK
IN. AS FLOW AGAIN TURNS AROUND TO THE SW...REGION SHOULD SEE
ANOTHER GRADUAL WARMUP FOR LATE WEEK.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
A CALM WIND UNDER HIGH PRESSURE SYSTEM WILL PROMOTE PATCHY VALLEY
FOG LATE TONIGHT. HOWEVER...LATEST MDL DATA AND EVENING IR SATL
LOOP SUGGESTS THERE WILL BE SOME PERSISTENT CU TONIGHT ACROSS
CENTRAL PA...LIMITING THE RADIATIONAL COOLING AND FOG THREAT.
BASED ON THIS AND LATEST RAP AND NAMPARA OUTPUT...HAVE DOWNPLAYED
THE FOG POTENTIAL ACROSS MUCH OF CENTRAL PA. HOWEVER...CONFIDENCE
NOT PARTICULARLY HIGH AND STILL CAN/T RULE OUT A PERIOD OF IFR
CONDS FROM FOG IN THE 07Z-13Z TIME FRAME.
ANY FOG THAT DOES FORM SHOULD BURN OFF BTWN 13Z-14Z. A
MOISTURE-STARVED COLD FRONT WILL BE PUSHING SE THRU THE REGION
THU AFTN. CAN/T RULE OUT AN ISOLD SHRA ACROSS THE N MTNS...BUT
CONFIDENCE IN VFR CONDS IS HIGH ACROSS ALL OF CENTRAL PA.
OUTLOOK...
FRI...PATCHY AM FOG POSSIBLE...MAINLY NORTH.
SAT...AM LOW CIGS/FOG POSSIBLE.
SUN...SLIGHT CHC OF PM TSRA IMPACTS W MTNS.
MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS/DEVOIR
SHORT TERM...ROSS
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
807 PM EDT WED SEP 17 2014
.SYNOPSIS...
A TROUGH OF LOW PRESSURE OVER EASTERN NORTH AMERICA WILL SLOWLY
WEAKEN INTO SATURDAY BEFORE RE-INTENSIFYING LATER ON SUNDAY ONCE
AGAIN. OVERALL IT SHOULD BE A RELATIVELY COOL AND DRY PERIOD WITH
A BRIEF WARM UP OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH PRESSURE MAINTAINING FAIR AND DRY CONDITIONS ACROSS CENTRAL
PA ONCE AGAIN THIS EVENING. PATCHY VALLEY FOG WILL BE THE ONLY
SENSIBLE WEATHER LATER TONIGHT. MIN TEMPS WILL STILL BE ON THE
COOL SIDE...RANGING FROM THE LOWER TO MIDDLE 40S OVER THE
NORTHERN TWO THIRDS OF CENTRAL PA...TO THE LOWER 50S ACROSS THE
SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
ANOTHER DRY AND SEASONABLY COOL DAY. A WEAK FRONTAL BOUNDARY WILL
MOVE ACROSS THE REGION BRINGING SLIGHTLY COOLER AIR AND JUST
SCATTERED CLOUD COVER. THURSDAY NIGHT WILL BY QUITE COLD WITH
FROST POSSIBLE ACROSS THE COLDEST VALLEYS...AND A FROST ADVISORY
MAY HAVE TO BE ISSUED FOR PORTIONS OF WESTERN PA FOR FRIDAY
MORNING ON THURSDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WARMER AIR AND HIGHER MOISTURE WILL ADVECT INTO THE REGION THIS
WEEKEND ON INCREASING SW FLOW AROUND A HIGH PRESSURE AREA
/RETREATING TO THE EAST/. AT THE SAME TIME...TROUGH BEGINS TO
CARVE INTO ZONAL FLOW OVER THE GREAT LAKES AS A SYSTEM APPROACHES
PA FOR SUN/MON. THE RESULT WILL BE A PAIR OF ABOVE NORMAL
TEMPERATURE DAYS SAT-SUN WITH TEMPS MAINLY IN THE 70S...AND TAKING
A RUN AT 80F IN THE SE. WE/LL ALSO GET A BREAK FROM OUR RUN OF
CHILLY OVERNIGHTS AS LOWS REMAIN WELL INTO THE 40S AND 50S. SHOWER
ACTIVITY SHOULD REMAIN CONFINED TO THE UPPER MIDWEST THROUGH EARLY
SUNDAY.
THE CENTER OF THE APPROACHING LOW PRESSURE SYSTEM WILL REMAIN WELL
TO OUR NORTH...BUT A WEAK COLD FRONT WILL PUSH THROUGH PA SUNDAY
INTO SUN NIGHT. THIS WILL BE THE BEST CHANCE OF RAIN/SHOWERS
THROUGH DURATION OF THE EXTENDED FORECAST. THE LATEST ECMWF IS THE
WETTEST WITH QPF POTENTIALLY UP TO 0.25...WHILE THE GFS BRINGS
LIGHTER AMOUNTS.
THE 500 HPA TROUGH BEHIND THE FRONT DEEPENS OVER THE REGION MONDAY
INTO TUESDAY. THIS WILL KEEP MENTION FOR SCT INSTABILITY SHOWERS
MONDAY INTO TUESDAY...MAINLY IN HIGHER TERRAIN OF N/W CWA. COOLER
AIR ON NW FLOW WILL GRADUALLY FILTER BACK INTO THE REGION...WITH
MONDAY/S HIGHS ABOUT 8-10F COOLER AND TUESDAY FALLING ANOTHER 5F
OR SO. OVERNIGHT LOWS WILL SLIP BACK INTO THE 40S MON NIGHT...WITH
SOME MID/UPPER 30S POSS IN THE NORTHERN MTNS TUE NIGHT.
TROUGH LIFTS TO THE NE BY MIDWEEK AS HIGH PRESSURE SETTLES BACK
IN. AS FLOW AGAIN TURNS AROUND TO THE SW...REGION SHOULD SEE
ANOTHER GRADUAL WARMUP FOR LATE WEEK.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
A CALM WIND UNDER HIGH PRESSURE SYSTEM WILL PROMOTE PATCHY VALLEY
FOG LATE TONIGHT. HOWEVER...LATEST MDL DATA AND EVENING IR SATL
LOOP SUGGESTS THERE WILL BE SOME PERSISTENT CU TONIGHT ACROSS
CENTRAL PA...LIMITING THE RADIATIONAL COOLING AND FOG THREAT.
BASED ON THIS AND LATEST RAP AND NAMPARA OUTPUT...HAVE DOWNPLAYED
THE FOG POTENTIAL ACROSS MUCH OF CENTRAL PA. HOWEVER...CONFIDENCE
NOT PARTICULARLY HIGH AND STILL CAN/T RULE OUT A PERIOD OF IFR
CONDS FROM FOG IN THE 07Z-13Z TIME FRAME.
ANY FOG THAT DOES FORM SHOULD BURN OFF BTWN 13Z-14Z. A
MOISTURE-STARVED COLD FRONT WILL BE PUSHING SE THRU THE REGION
THU AFTN. CAN/T RULE OUT AN ISOLD SHRA ACROSS THE N MTNS...BUT
CONFIDENCE IN VFR CONDS IS HIGH ACROSS ALL OF CENTRAL PA.
OUTLOOK...
FRI...PATCHY AM FOG POSSIBLE...MAINLY NORTH.
SAT...AM LOW CIGS/FOG POSSIBLE.
SUN...SLIGHT CHC OF PM TSRA IMPACTS W MTNS.
MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS/DEVOIR
SHORT TERM...ROSS
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1034 PM CDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
PICTURE PERFECT WEATHER CONDITIONS ACROSS THE REGION THIS AFTERNOON
AS TEMPERATURES HAVE RISEN INTO THE 70S AND WINDS REMAIN LIGHT.
ONLY MINOR FORECAST CONCERNS THROUGH THE DAYBREAK HOURS. MINOR
SHORTWAVE OVER EASTERN MONTANA WILL DROP SOUTHEAST LATER THIS
EVENING. LATEST HRRR AND HOPWRF RUNS INDICATING THIS WAVE SHOULD
BEGIN PRODUCING WIDELY SCATTERED SHOWERS AS IT MOVES INTO THE AREA.
GENERALLY THESE WILL BE HIGH-BASED SHOWERS...AND GIVEN A RATHER
SUBSTANTIAL DRY SUB-CLOUD LAYER...ANTICIPATE A CONSIDERABLE
AMOUNT OF VIRGA OR A FEW SPRINKLES MAINLY WEST OF I-29 THROUGH
MIDNIGHT.
THE PASSAGE OF THIS UPPER WAVE WILL ALLOW A WEAK SURFACE BOUNDARY TO
DRIFT NORTHWARD EARLY TOMORROW MORNING..WITH LOW-LEVEL MOISTURE
STEADILY ADVECTING NORTHWARD. SHOULD SEE STRATUS DEVELOPMENT TOWARDS
DAYBREAK...AND CANNOT RULE OUT PATCHY FOG ESPECIALLY ALONG EDGE OF
ADVANCING STRATUS. LOW LEVEL ISENTROPIC PLOTS SHOW VERY WEAK LIFT
WITHIN THE CLOUD LAYER...BUT FEEL LIFT TOO WEAK TO SUPPORT DRIZZLE.
CLOUDS ARE EXPECTED TO HANG AROUND FOR MUCH OF THURSDAY...GRADUALLY
LIFTING AND SCATTERING IN THE AFTERNOON. TEMPERATURES WILL REMAIN
IN THE 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
LITTLE DOUBT THAT EXTENSIVE STRATUS WILL EXPAND/DEVELOP THURSDAY
NIGHT INTO EARLY FRIDAY WITH ENHANCED LOW LEVEL JET AND STRENGTHENING
INVERSION. FOG A BIT MORE PROBLEMATIC...LIKELY FAVORING WESTERN
EDGE OF THE CLOUD AREA...AND NEAR SURFACE SOUTHEAST TO SOUTH FLOW
PROVIDING INCREASING MOISTURE. SREF PROBABILITIES OF LOW CLOUDS
ARE EXTREMELY HIGH...BUT MODEST IN THE REALM OF LOWEST
VISIBILITIES...GENERALLY SUPPORTING THIS EXPECTATION. NOT TOO
ENTHUSIASTIC ABOUT PRECIPITATION CHANCES...ESPECIALLY IN THE
EVENING. A LITTLE ENHANCEMENT OF LIFT ON LEADING EDGE OF THE
WARMING TEMPS ALOFT OCCURS ACROSS NORTHEAST NEBRASKA BY AROUND
06Z...AND COULD BE JUST ENOUGH ELEVATED FORCING AND WEAK
INSTABILITY TO SHAKE OUT AN ISOLATED THUNDERSTORM HEADING THROUGH
SOUTHWEST MINNESOTA AND NORTHWEST IOWA ALONG ELEVATED THETA E
ADVECTION ZONE.
IF NOT FOR A MINIMAL CHANCE OF A SHOWER OR THUNDERSTORM LINGERING
EARLY FRIDAY IN THE FAR EAST/NORTHEAST...FRIDAY WILL BE A CAPPED
DAY AS TEMPS 800-750 HPA TEMPS WARM TO +15 TO +22C...WITH THE
MAIN BATTLE OF THE DAY OVER MAX TEMPERATURES SET BETWEEN THE
STRATUS AND THE SOUTHWESTERLY FLOW ALOFT. TREND HAS BEEN TO SLOW
DOWN THE EASTWARD PROGRESSION...WITH EARLY DAY CLOUDS AT LEAST
BACK TO WEST OF THE JAMES RIVER...AND PERHAPS HOLDING TOUGH INTO
VERY EARLY AFTERNOON TOWARD I 29. SHOULD EVENTUALLY CLEAR WITH
GOOD PUSH FROM WESTERLY COMPONENT AHEAD OF ADVANCING FRONTAL ZONE
REACHING THE FAR WESTERN CWA BY LATE DAY. ENOUGH INTERFERENCE
EARLY IN THE DAY EAST TO HOLD READINGS CLOSER TO 80 DEGREES...BUT
SOME AREAS TO THE WEST TOWARD LOWER JAMES AND LOWER BRULE WILL
GIVE A GOOD RUN AT UPPER 80S TO NEAR 90.
PRECIPITATION SHOULD BE EXCLUSIVELY POST FRONTAL ON FRIDAY
NIGHT...SOMEWHAT SCARCE EARLY ON...BUT GRADUALLY TAKING HOLD WITH
DEEPER POST FRONTAL QG LIFT...AND PERHAPS A LITTLE MID LEVEL
WEAK CONTRIBUTION TO MOISTURE BY THE TIME DEFORMATION REACHES THE
SOUTHEASTERN HALF OF THE CWA LATER AT NIGHT. NOT LOOKING FOR ANY
SEVERE STORMS WITH INSTABILITY LIMITED...AND EFFECTIVE SHEAR
REDUCED BY NOCTURNAL DECOUPLING AND THE DEGREE OF WESTERLY
PREFRONTAL COMPONENT.
BEHIND ANY LINGERING SHOWERS/THUNDER SATURDAY MORNING...LOOKS TO
BE A WELL-MIXED DAY...AND WITH MAIN COOLING HOLDING OFF UNTIL
SECONDARY WAVE PASSAGE TO THE EAST ON SATURDAY EVENING... WILL
LIKELY BE A FAIRLY WARM DAY...AND LAST ABOVE NORMAL FOR A FEW
DAYS. MIXING WOULD FAVOR MAINLY UPPER 70S TO LOWER 80S...ALONG
WITH BRISK MIDDAY AND AFTERNOON WINDS OF 15 TO 25 MPH.
FOR SUNDAY THROUGH WEDNESDAY...LOOKS LIKE A FAIRLY QUIET TIME
AS FLOW AMPLIFIES A BIT INTO EARLY WEEK WITH WESTERN RIDGE AND
EASTERN TROUGH...THEN WEAKENS AND TRANSLATES EASTWARD AS SEVERAL
SOLUTIONS INDICATE A WESTERN TROUGH PROGRESSING INTO THE AREA BY
LATER TUESDAY OR EARLY WEDNESDAY. WOULD NOT BE SURPRISED TO NEED
TO ADD IN A THREAT FOR SHOWER/THUNDER FOR TUESDAY NIGHT INTO
WEDNESDAY...BUT TIMING AND LOCATION OF UPPER TROUGH IN FLUX AT
THIS POINT AND NOT WORTH CLUTTERING UP THE FORECAST...ESPECIALLY
CONSIDERING THE RUN TO RUN SIGNIFICANT CHANGES IN MODELS OVER LAST
24 HOURS. STRETCHED OUT DIURNAL RANGE JUST A TOUCH ON MONDAY AND
TUESDAY WITH DRY SURFACE RIDGE SLIPPING THROUGH THE AREA...AND
MAINTAINING A TRAJECTORY INTO THE EAST ON TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1032 PM CDT WED SEP 17 2014
LIGHT SOUTHEASTERLY WINDS OVERNIGHT. POSSIBLE MVFR VISIBILITIES AT
KFSD AND KSUX TOWARD MORNING WITH POTENTIAL FOR
STRATUS...DISSIPATING LATER ON THURSDAY MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...DUX
LONG TERM...CHAPMAN
AVIATION...JM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
608 PM CDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
PICTURE PERFECT WEATHER CONDITIONS ACROSS THE REGION THIS AFTERNOON
AS TEMPERATURES HAVE RISEN INTO THE 70S AND WINDS REMAIN LIGHT.
ONLY MINOR FORECAST CONCERNS THROUGH THE DAYBREAK HOURS. MINOR
SHORTWAVE OVER EASTERN MONTANA WILL DROP SOUTHEAST LATER THIS
EVENING. LATEST HRRR AND HOPWRF RUNS INDICATING THIS WAVE SHOULD
BEGIN PRODUCING WIDELY SCATTERED SHOWERS AS IT MOVES INTO THE AREA.
GENERALLY THESE WILL BE HIGH-BASED SHOWERS...AND GIVEN A RATHER
SUBSTANTIAL DRY SUB-CLOUD LAYER...ANTICIPATE A CONSIDERABLE
AMOUNT OF VIRGA OR A FEW SPRINKLES MAINLY WEST OF I-29 THROUGH
MIDNIGHT.
THE PASSAGE OF THIS UPPER WAVE WILL ALLOW A WEAK SURFACE BOUNDARY TO
DRIFT NORTHWARD EARLY TOMORROW MORNING..WITH LOW-LEVEL MOISTURE
STEADILY ADVECTING NORTHWARD. SHOULD SEE STRATUS DEVELOPMENT TOWARDS
DAYBREAK...AND CANNOT RULE OUT PATCHY FOG ESPECIALLY ALONG EDGE OF
ADVANCING STRATUS. LOW LEVEL ISENTROPIC PLOTS SHOW VERY WEAK LIFT
WITHIN THE CLOUD LAYER...BUT FEEL LIFT TOO WEAK TO SUPPORT DRIZZLE.
CLOUDS ARE EXPECTED TO HANG AROUND FOR MUCH OF THURSDAY...GRADUALLY
LIFTING AND SCATTERING IN THE AFTERNOON. TEMPERATURES WILL REMAIN
IN THE 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
LITTLE DOUBT THAT EXTENSIVE STRATUS WILL EXPAND/DEVELOP THURSDAY
NIGHT INTO EARLY FRIDAY WITH ENHANCED LOW LEVEL JET AND STRENGTHENING
INVERSION. FOG A BIT MORE PROBLEMATIC...LIKELY FAVORING WESTERN
EDGE OF THE CLOUD AREA...AND NEAR SURFACE SOUTHEAST TO SOUTH FLOW
PROVIDING INCREASING MOISTURE. SREF PROBABILITIES OF LOW CLOUDS
ARE EXTREMELY HIGH...BUT MODEST IN THE REALM OF LOWEST
VISIBILITIES...GENERALLY SUPPORTING THIS EXPECTATION. NOT TOO
ENTHUSIASTIC ABOUT PRECIPITATION CHANCES...ESPECIALLY IN THE
EVENING. A LITTLE ENHANCEMENT OF LIFT ON LEADING EDGE OF THE
WARMING TEMPS ALOFT OCCURS ACROSS NORTHEAST NEBRASKA BY AROUND
06Z...AND COULD BE JUST ENOUGH ELEVATED FORCING AND WEAK
INSTABILITY TO SHAKE OUT AN ISOLATED THUNDERSTORM HEADING THROUGH
SOUTHWEST MINNESOTA AND NORTHWEST IOWA ALONG ELEVATED THETA E
ADVECTION ZONE.
IF NOT FOR A MINIMAL CHANCE OF A SHOWER OR THUNDERSTORM LINGERING
EARLY FRIDAY IN THE FAR EAST/NORTHEAST...FRIDAY WILL BE A CAPPED
DAY AS TEMPS 800-750 HPA TEMPS WARM TO +15 TO +22C...WITH THE
MAIN BATTLE OF THE DAY OVER MAX TEMPERATURES SET BETWEEN THE
STRATUS AND THE SOUTHWESTERLY FLOW ALOFT. TREND HAS BEEN TO SLOW
DOWN THE EASTWARD PROGRESSION...WITH EARLY DAY CLOUDS AT LEAST
BACK TO WEST OF THE JAMES RIVER...AND PERHAPS HOLDING TOUGH INTO
VERY EARLY AFTERNOON TOWARD I 29. SHOULD EVENTUALLY CLEAR WITH
GOOD PUSH FROM WESTERLY COMPONENT AHEAD OF ADVANCING FRONTAL ZONE
REACHING THE FAR WESTERN CWA BY LATE DAY. ENOUGH INTERFERENCE
EARLY IN THE DAY EAST TO HOLD READINGS CLOSER TO 80 DEGREES...BUT
SOME AREAS TO THE WEST TOWARD LOWER JAMES AND LOWER BRULE WILL
GIVE A GOOD RUN AT UPPER 80S TO NEAR 90.
PRECIPITATION SHOULD BE EXCLUSIVELY POST FRONTAL ON FRIDAY
NIGHT...SOMEWHAT SCARCE EARLY ON...BUT GRADUALLY TAKING HOLD WITH
DEEPER POST FRONTAL QG LIFT...AND PERHAPS A LITTLE MID LEVEL
WEAK CONTRIBUTION TO MOISTURE BY THE TIME DEFORMATION REACHES THE
SOUTHEASTERN HALF OF THE CWA LATER AT NIGHT. NOT LOOKING FOR ANY
SEVERE STORMS WITH INSTABILITY LIMITED...AND EFFECTIVE SHEAR
REDUCED BY NOCTURNAL DECOUPLING AND THE DEGREE OF WESTERLY
PREFRONTAL COMPONENT.
BEHIND ANY LINGERING SHOWERS/THUNDER SATURDAY MORNING...LOOKS TO
BE A WELL-MIXED DAY...AND WITH MAIN COOLING HOLDING OFF UNTIL
SECONDARY WAVE PASSAGE TO THE EAST ON SATURDAY EVENING... WILL
LIKELY BE A FAIRLY WARM DAY...AND LAST ABOVE NORMAL FOR A FEW
DAYS. MIXING WOULD FAVOR MAINLY UPPER 70S TO LOWER 80S...ALONG
WITH BRISK MIDDAY AND AFTERNOON WINDS OF 15 TO 25 MPH.
FOR SUNDAY THROUGH WEDNESDAY...LOOKS LIKE A FAIRLY QUIET TIME
AS FLOW AMPLIFIES A BIT INTO EARLY WEEK WITH WESTERN RIDGE AND
EASTERN TROUGH...THEN WEAKENS AND TRANSLATES EASTWARD AS SEVERAL
SOLUTIONS INDICATE A WESTERN TROUGH PROGRESSING INTO THE AREA BY
LATER TUESDAY OR EARLY WEDNESDAY. WOULD NOT BE SURPRISED TO NEED
TO ADD IN A THREAT FOR SHOWER/THUNDER FOR TUESDAY NIGHT INTO
WEDNESDAY...BUT TIMING AND LOCATION OF UPPER TROUGH IN FLUX AT
THIS POINT AND NOT WORTH CLUTTERING UP THE FORECAST...ESPECIALLY
CONSIDERING THE RUN TO RUN SIGNIFICANT CHANGES IN MODELS OVER LAST
24 HOURS. STRETCHED OUT DIURNAL RANGE JUST A TOUCH ON MONDAY AND
TUESDAY WITH DRY SURFACE RIDGE SLIPPING THROUGH THE AREA...AND
MAINTAINING A TRAJECTORY INTO THE EAST ON TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 602 PM CDT WED SEP 17 2014
EXPECT CU FIELD TO CONTINUE TO DISSIPATE THROUGH THE EARLY
EVENING...OTHERWISE LIGHT SOUTHEASTERLY WINDS THROUGH THE
OVERNIGHT. POSSIBLE MVFR VISIBILITIES TOWARD MORNING WITH
POTENTIAL FOR STRATUS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...DUX
LONG TERM...CHAPMAN
AVIATION...JM
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
948 PM CDT WED SEP 17 2014
.UPDATE...
DECREASED POPS OVERNIGHT DUE TO CURRENT CONDITIONS. STILL
CONFIDENT IN THE HRRR SOLUTION OF SHOWERS IN THE MORNING.
INCREASED CLOUD COVER THROUGHOUT THE DAY TOMORROW TO REFLECT THE
INCREASED MOISTURE ASSOCIATED WITH THE DISTURBANCE APPROACHING THE
AREA.
JPM3
&&
.PREV DISCUSSION... /ISSUED 741 PM CDT WED SEP 17 2014/
UPDATE...
PREVIOUS FORECAST LOOKS TO BE ON TRACK FOR THE OVERNIGHT...EARLY
MORNING PERIOD. ONLY MINOR CHANGES WERE NEEDED. ADDED PATCHY FOG DUE
TO ABUNDANT LOW LEVEL MOISTURE IN NORTHEAST ARKANSAS. HRRR MODEL
HAS SHOWERS DEVELOPING IN THE EARLY MORNING HOURS AS A WEAK UPPER
LEVEL DISTURBANCE APPROACHES THE MID SOUTH...POPS WERE INCREASED SLIGHTLY
FOR NORTHEASTERN ARKANSAS... THE MISSOURI BOOTHEEL... AND WEST
TENNESSEE.
JPM3
DISCUSSION...
PREV DISCUSSION... /ISSUED 613 PM CDT WED SEP 17 2014/
DISCUSSION... /ISSUED 321 PM CDT WED SEP 17 2014/
NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE MIDSOUTH THROUGH EARLY
FRIDAY. IN THE SHORT TERM... AN MCS OVER NORTHERN AR WILL DRIFT SE
THIS EVENING. UPSTREAM REAR PROPAGATION TENDENCIES THIS EVENING
MAY RESULT IN ADDITIONAL SHOWERS AND THUNDERSTORMS EVENTUALLY
MOVING INTO EASTERN AR AND PERHAPS WEST TN AND NORTHWEST MS
OVERNIGHT.
SHORT TERM MODELS VARY A BIT WITH UPSTREAM CONVECTIVE INITIATION
EARLY ON THURSDAY. GOES WATER VAPOR IMAGERY SHOWED A WEAK SHORTWAVE
MOVING INTO THE WESTERN NEBR PANHANDLE THAT COULD HELP ENHANCE
CONVECTION OVER THE OZARK PLATEAU AND PERHAPS PORTIONS OF THE
MIDSOUTH ON THURSDAY.
BY FRIDAY... AN UPPER LEVEL HEIGHT RIDGE WILL MOVE INTO THE LOWER
MS RIVER VALLEY FROM THE SOUTHERN PLAINS. RESIDUAL MOISTURE FROM
TROPICAL DEPRESSION ODILE WILL OVERRIDE THE TOP OF THE RIDGE...
EVENTUALLY CONSOLIDATING INTO THE BASE OF A NORTHERN BRANCH
LONGWAVE TROF DROPPING INTO TO THE OHIO VALLEY. THIS MOISTURE WILL
MAKE A BRIEF APPEARANCE IN THE MIDSOUTH ON SUNDAY... FOLLOWED BY
DRY NORTHWEST FLOW ALOFT. 12Z ECMWF AND GFS WERE IN GOOD AGREEMENT
FOR THE SUNDAY THROUGH TUESDAY PERIODS.
UPPER HEIGHTS WILL BUILD AGAIN TOWARD THE MIDDLE PART OF NEXT
WEEK...AS THE EASTERN CONUS LONGWAVE TROF LIFTS OUT TO CANADIAN
MARITIMES. A WEAK SLOW MOVING TROF OVER THE SOUTHERN PLAINS WILL
KEEP RAIN CHANCES WELL TO THE WEST...WHILE DRIER LOW LEVELS AND
UPPER RIDGING LIMIT MIDWEEK RAIN CHANCES FOR THE MIDSOUTH.
PWB
AVIATION...
00Z TAF SET
AN AREA OF SHRAS CONTINUES TO MOVE THROUGH THE CWA. MODELS
INDICATING REDEVELOPMENT OF SHRAS/TSRAS ACROSS SW MO THIS EVENING.
THE SHRAS/TSRAS WOULD PUSH INTO KJBR AROUND 6-7Z...POSSIBLY
GETTING TO KMEM AROUND 9Z. WILL MENTION VCTS WORDING. CIGS WILL
GRADUALLY LOWER TO MVFR TONIGHT. SHOULD RETURN TO VFR DURING THE
MORNING HOURS. GENERALLY LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE
PERIOD.
KRM
&&
.AVIATION...
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
746 PM CDT WED SEP 17 2014
.DISCUSSION...
IMPULSE WORKING SOUTHEASTWARD ACROSS NORTHERN AR AT THIS TIME. MID
AND HIGH LEVEL CLOUDINESS DOES EXTEND EASTWARD ACROSS THE MID
STATE WITH LOW CLOUDS BACK ACROSS MISSOURI. LATEST HRRR IS
OVERDOING THE CONVECTION FOR THIS EVENING. IN FACT...NO
PRECIPITATION IS INDICATED ACROSS THE MID STATE CURRENTLY.
MODELS DO SHOW...HOWEVER...A RETURN OF MOISTURE AT THE 700 MB TO
850 MB LEVEL TOWARD AND BEYOND 06Z. LIGHT QPF IS HINTED TOWARD BY
THE MODELS AFTER 06Z TONIGHT...MAINLY WESTERN AREAS. THIS IS IN
LINE WITH THE CURRENT ISC THINKING AS WELL. THUS...WILL REMOVE
EVENING PRECIP BUT INCLUDE A 20 PERCENT CHANCE OF SHOWERS FOR
WESTERN AREAS AFTER MIDNIGHT. WILL ALSO INCREASE THE SKY COVERAGE
TO INCLUDE MOSTLY CLOUDY SKIES FOR A LONGER DURATION ACROSS MUCH
OF THE CENTRAL AND WESTERN AREAS.
AS FOR FOG POTENTIAL...TOVER VALUES WILL BE HIGHER AND ARE NEAR
ZERO FOR THE UPCOMING 12Z PERIOD. ALSO...MODELS ARE NOT AS BULLISH
WITH THE LOW DEWPOINT DEPRESSIONS AROUND 12Z AS WELL. WILL
THEREFORE CONTINUE TO LEAVE THE FOG OUT OF THE FCST.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 705 PM CDT WED SEP 17 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
PER MID TO UPPER LEVEL SHORTWAVE PASSAGE EXPECTED ACROSS MID STATE THRU 18/12Z...
ISO LIGHT SHWR DEVELOPMENT POSSIBLE...BUT LOCATION DEVELOPMENT SO UNCERTAIN/VSBY
IMPACTS MINIMAL...SHOULD HAVE LITTLE IF ANY TAF SITE IMPACTS...THUS DID NOT
MENTION. NWLY FLOW ALOFT SHOULD SUPPORT PROGRESSION OF MID TO UPPER LEVEL
MOISTURE ACROSS MID STATE THRU 18/12Z...WITH THE POTENTIAL OF CLRING BEHIND
SHORTWAVE PASSAGE NW TO SE...AND ALONG WITH LIGHT TO CALM WINDS...SUPPORTING
MVFR TO IFR FOG TAF SITES THRU 18/14Z. EXPECT DRIER AIRMASS TO WORK INTO MID
STATE THRU 18/24Z WITH DIURNAL SCT CU AND SCT CI IN NWLY FLOW ALOFT EXPECTED.
PREV DISCUSSION.../ISSUED 218 PM CDT WED SEP 17 2014/
DISCUSSION...
LATEST INFRARED SHOWING TOPS WARMING ALONG ARKANSAS/MISSOURI BORDER
AS COMPLEX CONTINUES TO DIVE SOUTHEASTWARD IN NORTHWESTERLY FLOW ALOFT.
DEBRIS CLOUDS ALREADY SPILLING INTO MIDDLE TENNESSEE THIS
AFTERNOON. I`M NOT COMFORTABLE LEAVING POPS OUT ALTOGETHER FOR
TONIGHT SINCE MID AND UPPER LEVEL SHORT WAVE IS GOING TO WORK
ACROSS OUR AREA DURING THE NIGHT. EURO AND NAM SHOW SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS AS WE THROUGH THE OVERNIGHT.
MET MOS ACTUALLY HAS A 41 POP WHILE MAV MOS HAS 8 AT NASHVILLE FOR
TONIGHT. H-TRIPLE-R BREAKS SHOWERS AND ISOLATED THUNDER OUT AS
WELL TONIGHT. LATEST SREF RUN KEEPS THUNDER WELL WEST OF MY CWA.
NORTHWESTERLY FLOW WILL CONTINUE WEDNESDAY AND THURSDAY WITH UPPER RIDGE
BUILDING IN OVER THE SOUTHERN U.S. BY FRIDAY WITH WESTERLY BELT ALONG
NORTHERN U.S. CANADIAN BORDER. BELT BUCKLES ON SATURDAY AS UPPER RIDGE
BUILDS UP THROUGH THE ROCKY MOUNTAIN REGION WITH A RATHER DEEP TROUGH
BEING CARVED OUT OVER EASTERN U.S INTO MONDAY. THIS WILL ALLOW FOR
A SERIES OF CANADIAN COLD FRONTS TO MOVE DOWN AND THROUGH THE MID
STATE BEGINNING ON SUNDAY. THIS FRONT WILL BE ACCOMPANIED BY SHOWERS
AND A FEW THUNDERSTORMS SUNDAY INTO MONDAY. ANOTHER FRONT ALBEIT
DRY MOVES DOWN ON TUESDAY OF NEXT WEEK ONLY TO REINFORCE THE CONTINENTAL
POLAR AIRMASS THAT`S ALREADY IN PLACE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
741 PM CDT WED SEP 17 2014
.UPDATE...
PREVIOUS FORECAST LOOKS TO BE ON TRACK FOR THE OVERNIGHT...EARLY
MORNING PERIOD. ONLY MINOR CHANGES WERE NEEDED. ADDED PATCHY FOG DUE
TO ABUNDANT LOW LEVEL MOISTURE IN NORTHEAST ARKANSAS. HRRR MODEL
HAS SHOWERS DEVELOPING IN THE EARLY MORNING HOURS AS A WEAK UPPER
LEVEL DISTURBANCE APPROACHES THE MID SOUTH...POPS WERE INCREASED SLIGHTLY
FOR NORTHEASTERN ARKANSAS... THE MISSOURI BOOTHEEL... AND WEST
TENNESSEE.
JPM3
&&
.DISCUSSION...
&&
.PREV DISCUSSION... /ISSUED 613 PM CDT WED SEP 17 2014/
DISCUSSION... /ISSUED 321 PM CDT WED SEP 17 2014/
NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE MIDSOUTH THROUGH EARLY
FRIDAY. IN THE SHORT TERM... AN MCS OVER NORTHERN AR WILL DRIFT SE
THIS EVENING. UPSTREAM REAR PROPAGATION TENDENCIES THIS EVENING
MAY RESULT IN ADDITIONAL SHOWERS AND THUNDERSTORMS EVENTUALLY
MOVING INTO EASTERN AR AND PERHAPS WEST TN AND NORTHWEST MS
OVERNIGHT.
SHORT TERM MODELS VARY A BIT WITH UPSTREAM CONVECTIVE INITIATION
EARLY ON THURSDAY. GOES WATER VAPOR IMAGERY SHOWED A WEAK SHORTWAVE
MOVING INTO THE WESTERN NEBR PANHANDLE THAT COULD HELP ENHANCE
CONVECTION OVER THE OZARK PLATEAU AND PERHAPS PORTIONS OF THE
MIDSOUTH ON THURSDAY.
BY FRIDAY... AN UPPER LEVEL HEIGHT RIDGE WILL MOVE INTO THE LOWER
MS RIVER VALLEY FROM THE SOUTHERN PLAINS. RESIDUAL MOISTURE FROM
TROPICAL DEPRESSION ODILE WILL OVERRIDE THE TOP OF THE RIDGE...
EVENTUALLY CONSOLIDATING INTO THE BASE OF A NORTHERN BRANCH
LONGWAVE TROF DROPPING INTO TO THE OHIO VALLEY. THIS MOISTURE WILL
MAKE A BRIEF APPEARANCE IN THE MIDSOUTH ON SUNDAY... FOLLOWED BY
DRY NORTHWEST FLOW ALOFT. 12Z ECMWF AND GFS WERE IN GOOD AGREEMENT
FOR THE SUNDAY THROUGH TUESDAY PERIODS.
UPPER HEIGHTS WILL BUILD AGAIN TOWARD THE MIDDLE PART OF NEXT
WEEK...AS THE EASTERN CONUS LONGWAVE TROF LIFTS OUT TO CANADIAN
MARITIMES. A WEAK SLOW MOVING TROF OVER THE SOUTHERN PLAINS WILL
KEEP RAIN CHANCES WELL TO THE WEST...WHILE DRIER LOW LEVELS AND
UPPER RIDGING LIMIT MIDWEEK RAIN CHANCES FOR THE MIDSOUTH.
PWB
&&
.AVIATION...
00Z TAF SET
AN AREA OF SHRAS CONTINUES TO MOVE THROUGH THE CWA. MODELS
INDICATING REDEVELOPMENT OF SHRAS/TSRAS ACROSS SW MO THIS EVENING.
THE SHRAS/TSRAS WOULD PUSH INTO KJBR AROUND 6-7Z...POSSIBLY
GETTING TO KMEM AROUND 9Z. WILL MENTION VCTS WORDING. CIGS WILL
GRADUALLY LOWER TO MVFR TONIGHT. SHOULD RETURN TO VFR DURING THE
MORNING HOURS. GENERALLY LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE
PERIOD.
KRM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
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
National Weather Service Spokane WA
850 PM PDT WED SEP 17 2014
.SYNOPSIS...
A weak cold front will move through Washington and Idaho on
Thursday. The front will push temperatures closer to normal and
bring the potential for widely scattered showers on Thursday. A
high pressure ridge will return Friday and promote warm and dry
weather through the weekend.
&&
.DISCUSSION...
Evening update: tracking a jet streaking coming up through
CA/southern OR and projected to advance toward northeast
OR/southeast WA/central ID late overnight into Thursday morning.
Both the HRRR and NAM Hi-Res have been indicating some shower
threat expanding up through south-central/eastern OR and southern
ID the Blues/Camas Prairie and Central Panhandle between 09Z and
15 or 18Z Thursday (late overnight into Thursday morning). Some
guidance suggest perhaps as far northwest as the Pullman area, but
confidence is not great enough to go that far north. I wouldn`t be
surprised to see some sprinkles that far north though. Overall I
increased PoPs and sky cover over southeast WA through the central
Panhandle. I kept some mention of smoke in that region through
early overnight before the potential shower threat will less than
threat. But this will continue to be assessed. Otherwise the
forecast looks on track and overall the precipitation that comes
with this system still does not look overwhelming. /J. Cote`
&&
.AVIATION...
00Z TAFS: A moist southwest flow and approaching cold front/upper
trough will impact the Inland NW over the next 24 or so hours. The
system appears to stretch and split moving inland, but will still
provide some increased cloud cover and the threat of a few
showers. The best shower chances will be near the Cascades,
including EAT, and over the northeast mountains going into later
tonight into Thursday. There is a small threat near the GEG to COE
and PUW/LWS sites, but the risk is still low to mention in the
TAF. There is also the potential for a few thunderstorms across
the NE MTNS of WA and north ID, but the risk for this is also low.
As the front pushes through look for increased winds Thursday
afternoon, with gusts in the 20 to 25kt range. Lastly, smoke from
nearby wildfires will locally reduce visibilities to MVFR
conditions near PUW/LWS this evening, possibly into the morning,
but guidance suggests its intensity wanes over Wednesday evening.
/J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 80 56 76 51 80 / 0 20 10 10 0 0
Coeur d`Alene 55 80 55 76 50 80 / 0 20 20 10 0 0
Pullman 53 80 53 76 49 81 / 0 20 10 0 0 0
Lewiston 60 86 59 82 56 86 / 0 20 10 0 0 0
Colville 53 81 51 80 47 83 / 10 30 20 10 0 0
Sandpoint 49 75 51 73 46 76 / 0 30 30 10 10 0
Kellogg 55 77 53 72 50 78 / 10 30 20 10 0 0
Moses Lake 58 83 56 84 52 86 / 10 10 10 0 0 0
Wenatchee 64 82 61 83 58 84 / 20 20 10 0 0 0
Omak 58 82 55 82 49 85 / 20 30 20 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1018 PM CDT WED SEP 17 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE
TROUGH MOVING SOUTHEAST OVER THE UPPER PENINSULA AND A STRONG COLD
FRONT DROPPING SOUTH OVER THE UPPER PENINSULA OF MICHIGAN.
SCATTERED SHOWERS OVER LAKE SUPERIOR ARE EXITING THE REGION AHEAD OF
THE SHORTWAVE. BUT THERE IS A FAIRLY WIDESPREAD AREA OF LOW STRATUS
BEHIND THE FRONT...THOUGH STARTING TO SEE SOME BREAKS IN THE
OVERCAST OCCUR OVER NORTHERN MINNESOTA AND LAKE SUPERIOR. NORTHEAST
WINDS ARE ALSO QUITE GUSTY RIGHT BEHIND THE FRONT COINCIDENT WITH
MODEST PRESSURE RISES...AND SOME GUSTS ARE REACHING 30 KTS OVER
SOUTHERN LAKE SUPERIOR. A CANADIAN SURFACE HIGH IS BUILDING
SOUTHEAST BEHIND THE FRONT AND USHERING IN ANOTHER COLD POLAR
AIRMASS WITH SOME SNOW BEING REPORTED JUST NORTH OF LAKE SUPERIOR.
AS THE FRONT DROPS SOUTH...SMALL PRECIP CHANCES...FROST/FREEZE
HEADLINES...AND WIND GUSTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE BACKDOOR COLD FRONT WILL CONTINUE TO SLIDE SOUTH
ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING
HOURS...BEFORE SETTLING OVER SOUTHERN WISCONSIN OVERNIGHT.
MID-LEVEL MOISTURE WILL BE EXITING WITH THE SHORTWAVE THIS
AFTERNOON...SO NOT ANTICIPATING ANY SHOWERS WITH THE FRONT. BUT DO
EXPECT A BAND OF LOW CLOUDS TO ACCOMPANY THE FRONT...ALONG WITH A
WIND SHIFT TO THE NORTHEAST. WITH THE WIND SHIFT...WINDS COULD
BECOME QUITE GUSTY OVER NORTHEAST WISCONSIN...AS TRAJECTORIES WILL
BE FAVORABLE FOR FUNNELING DOWN THE BAY OF GREEN BAY. SOME GUSTS TO
30 MPH ARE POSSIBLE. SOME LOW STRATUS WILL LIKELY LINGER OVER
CENTRAL AND EAST-CENTRAL WISCONSIN THROUGH THE NIGHT...BUT
SUBSIDENCE WILL LIKELY LEAD TO CLEARING OVER N-C WISCONSIN
OVERNIGHT. AS WINDS DIMINISH...THE LEADING GUIDANCE SHOWS LOW TEMPS
FALLING INTO THE UPPER 20S TO MID 30S OVER N-C WISCONSIN. WILL
HOIST A FROST ADVISORY FOR THAT REGION. GREATER CLOUD COVER AND
WIND SPEEDS SHOULD KEEP AREAS SAFE FROM THE FROST FURTHER SOUTH AND
EAST.
THURSDAY...PLENTY OF LOW LEVEL MOISTURE WILL LINGER BEHIND THE FRONT
OVER CENTRAL AND EAST-CENTRAL WISCONSIN IN THE MORNING...WHICH WILL
GRADUALLY RETURN NORTHWARD DURING THE AFTERNOON.
THEREFORE...ANTICIPATE SCT TO BKN CLOUDS TO EXPAND WITH HEATING OF
THE DAY. WITH THE CLOUD COVER AND SHALLOW COLD AIRMASS...HIGHS WILL
RANGE FROM THE MIDDLE 50S TO LOWER 60S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
ZONAL FLOW OVER THE NORTHERN CONUS LATE THIS WEEK WILL QUICKLY
TRANSITION TO MORE HIGHLY AMPLIFIED PATTERN...CHARACTERIZED BY DEEP
TROUGH OVER THE GREAT LAKES AND RIDGE OVER WESTERN CANADA...BY EARLY
NEXT WEEK. FORECAST CHALLENGE EARLY IN THE EXTENDED WILL BE CENTERED
AROUND TIMING AND INTENSITY OF INITIAL SHORTWAVE IMPULSES EMBEDDED
WITHIN ZONAL FLOW FRIDAY INTO SATURDAY. THEREAFTER GREAT LAKES
WILL BE DOMINATED NORTHWESTERLY UPPER-LEVEL FLOW AND BROAD HIGH
PRESSURE DURING THE FIRST HALF OF NEXT WEEK. BEST OPPORTUNITY FOR
SUBSTANTIAL RAINFALL WILL BE EARLY IN THE PERIOD FOLLOWED BY
MAINLY DRY CONDITIONS AT LEAST THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL START OUT ABOVE NORMAL FRIDAY AND SATURDAY...THEN
FALL BACK TO WELL BELOW NORMAL TOWARD THE MIDDLE PART OF NEXT
WEEK...WITH CHILLY NIGHTS AND POTENTIAL FOR AREAS OF FROST ACROSS
PARTS OF CENTRAL AND NORTHERN WISCONSIN.
INITIAL FORECAST CHALLENGE WILL BE TIMING OF SHOWER AND SCATTERED
THUNDERSTORMS ACTIVITY FRIDAY AFTERNOON AND EVENING WITH
APPROACHING SHORTWAVE IMPULSE...IN CONCERT WITH INCREASING LOW-
LEVEL WAA IN WAKE OF DEPARTING HIGH PRESSURE. WARM ADVECTION
BECOMES QUITE ROBUST BY 00Z SATURDAY AS 850 MB SOUTHWESTERLY WINDS
APPROACH 40 KTS. APPEARS MAJORITY OF LATEST MODEL GUIDANCE ARE A
BIT SLOWER ON INITIAL SHORTWAVE IMPULSE THUS HAVE TRIMMED BACK POPS
ACROSS THE EASTERN HALF OF THE FORECAST AREA IN THE 12Z TO 18Z
TIME FRAME FOR FRIDAY. APPEARS BEST FORCING WILL BE OVER NORTHERN
PORTION OF THE FORECAST AREA LATE FRIDAY AFTERNOON INTO FRIDAY
AND HAVE ADJUSTED POPS ACCORDINGLY. ON FRIDAY NIGHT...THE FORECAST
AREA SHOULD BE BECOME INCREASINGLY UNDER THE INFLUENCE OF THE RRQ
OF AN UPPER LEVEL JET THUS EXPECT GENERAL INCREASE IN ORGANIZED SCALE
SYNOPTIC SCALE LIFT AND DESTABILIZATION AHEAD OF SURFACE COLD
FRONT MOVING INTO CENTRAL MINNESOTA BY 06Z. ALTHOUGH STILL MODEL
DIFFERENCES IN LOCATION OF HEAVIEST QPF OVERNIGHT...ALL GUIDANCE
SUGGEST AN OVERALL INCREASE IN COVERAGE OF SHOWER AND THUNDERSTORM
ACTIVITY.
SATURDAY A BIT MORE UNCERTAIN AS STILL A FAIR AMOUNT OF MODEL
SPREAD ON TIMING OF COLD FRONT ACROSS THE FORECAST AREA. ECMWF
FASTER THAN MOST OF THE OTHER GUIDANCE. OPTED TO LEAN MORE TOWARD
A BLEND OF THE SREF MEAN AND ECMWF WHICH SUGGEST A SOMEWHAT FASTER
PROGRESSION. ADJUSTED POPS ACCORDINGLY WITH LIKELY POPS IN THE
MORNING AND TAPERED TOWARD CHANCE DURING THE AFTERNOON. GIVEN
THIS SCENARIO APPEARS ANY DEEP CONVECTION THAT CAN DEVELOP ALONG
THE COLD FRONT DURING THE AFTERNOON WILL MOST LIKELY OCCUR OVER
THE SOUTHEAST HALF OF THE STATE. IF ECMWF IS CORRECT...SATURDAY
AFTERNOON COULD BE MAINLY DRY. IF ENOUGH CLEARING CAN OCCUR
DAYTIME TEMPS SHOULD BE ABLE TO RESPOND AND RISE WELL INTO THE 70S
AS 850 TEMPS REALLY DO NOT FALL MUCH BEHIND THE COLD FRONT
INITIALLY.
ON SATURDAY NIGHT PRONOUNCED LFQ OF UPPER JET THEN PUSHES INTO
THE AREA WITH PRIMARY SHORTWAVE TROUGH CONTINUING TO DEEPEN OVER
THE AREA. WOULD EXPECT TO SEE SHOWER ACTIVITY INCREASE OVERNIGHT
SATURDAY ESPECIALLY ACROSS THE NORTH. UPPER TROUGH AXIS WILL
PERSIST OVER THE AREA ON SUNDAY WITH CAA CONTINUING. SCENARIO
FAVORABLE FOR AFTERNOON DIURNAL SHOWER ACTIVITY TO DEVELOP OVER
THE NORTHERN PORTION OF THE FORECAST AREA. LEFT SMALL POPS IN FOR
SUNDAY TO ACCOUNT FOR THIS.
HIGH PRESSURE FINALLY BUILDS IN SUNDAY NIGHT AND MONDAY BRINGING A
STRETCH OF DRIER WEATHER INTO AT LEAST MIDWEEK. EXPECT TEMPS TO BE
BELOW NORMAL THROUGH THE FIRST HALF OF THE WEEK WITH POTENTIAL FOR
SOME EARLY MORNING FROST OR FREEZE ESPECIALLY ON TUESDAY MORNING.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1017 PM CDT WED SEP 17 2014
AN AREA OF MVFR CIGS WITH PATCHY IFR CIGS WILL DROP
SOUTH OVER THE AREA IN THE WAKE OF A COLD FRONT. ANTICIPATE VFR
CONDITIONS TO RETURN FROM NORTH TO SOUTH OVERNIGHT AS DRIER AIR
WORKS INTO THE REGION FROM THE NORTH. VFR CONDITIONS TO CONTINUE
INTO THURSDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR WIZ010>013-018-019.
FREEZE WARNING UNTIL 8 AM CDT THURSDAY FOR WIZ005.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
635 PM CDT WED SEP 17 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE
TROUGH MOVING SOUTHEAST OVER THE UPPER PENINSULA AND A STRONG COLD
FRONT DROPPING SOUTH OVER THE UPPER PENINSULA OF MICHIGAN.
SCATTERED SHOWERS OVER LAKE SUPERIOR ARE EXITING THE REGION AHEAD OF
THE SHORTWAVE. BUT THERE IS A FAIRLY WIDESPREAD AREA OF LOW STRATUS
BEHIND THE FRONT...THOUGH STARTING TO SEE SOME BREAKS IN THE
OVERCAST OCCUR OVER NORTHERN MINNESOTA AND LAKE SUPERIOR. NORTHEAST
WINDS ARE ALSO QUITE GUSTY RIGHT BEHIND THE FRONT COINCIDENT WITH
MODEST PRESSURE RISES...AND SOME GUSTS ARE REACHING 30 KTS OVER
SOUTHERN LAKE SUPERIOR. A CANADIAN SURFACE HIGH IS BUILDING
SOUTHEAST BEHIND THE FRONT AND USHERING IN ANOTHER COLD POLAR
AIRMASS WITH SOME SNOW BEING REPORTED JUST NORTH OF LAKE SUPERIOR.
AS THE FRONT DROPS SOUTH...SMALL PRECIP CHANCES...FROST/FREEZE
HEADLINES...AND WIND GUSTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE BACKDOOR COLD FRONT WILL CONTINUE TO SLIDE SOUTH
ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING
HOURS...BEFORE SETTLING OVER SOUTHERN WISCONSIN OVERNIGHT.
MID-LEVEL MOISTURE WILL BE EXITING WITH THE SHORTWAVE THIS
AFTERNOON...SO NOT ANTICIPATING ANY SHOWERS WITH THE FRONT. BUT DO
EXPECT A BAND OF LOW CLOUDS TO ACCOMPANY THE FRONT...ALONG WITH A
WIND SHIFT TO THE NORTHEAST. WITH THE WIND SHIFT...WINDS COULD
BECOME QUITE GUSTY OVER NORTHEAST WISCONSIN...AS TRAJECTORIES WILL
BE FAVORABLE FOR FUNNELING DOWN THE BAY OF GREEN BAY. SOME GUSTS TO
30 MPH ARE POSSIBLE. SOME LOW STRATUS WILL LIKELY LINGER OVER
CENTRAL AND EAST-CENTRAL WISCONSIN THROUGH THE NIGHT...BUT
SUBSIDENCE WILL LIKELY LEAD TO CLEARING OVER N-C WISCONSIN
OVERNIGHT. AS WINDS DIMINISH...THE LEADING GUIDANCE SHOWS LOW TEMPS
FALLING INTO THE UPPER 20S TO MID 30S OVER N-C WISCONSIN. WILL
HOIST A FROST ADVISORY FOR THAT REGION. GREATER CLOUD COVER AND
WIND SPEEDS SHOULD KEEP AREAS SAFE FROM THE FROST FURTHER SOUTH AND
EAST.
THURSDAY...PLENTY OF LOW LEVEL MOISTURE WILL LINGER BEHIND THE FRONT
OVER CENTRAL AND EAST-CENTRAL WISCONSIN IN THE MORNING...WHICH WILL
GRADUALLY RETURN NORTHWARD DURING THE AFTERNOON.
THEREFORE...ANTICIPATE SCT TO BKN CLOUDS TO EXPAND WITH HEATING OF
THE DAY. WITH THE CLOUD COVER AND SHALLOW COLD AIRMASS...HIGHS WILL
RANGE FROM THE MIDDLE 50S TO LOWER 60S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
ZONAL FLOW OVER THE NORTHERN CONUS LATE THIS WEEK WILL QUICKLY
TRANSITION TO MORE HIGHLY AMPLIFIED PATTERN...CHARACTERIZED BY DEEP
TROUGH OVER THE GREAT LAKES AND RIDGE OVER WESTERN CANADA...BY EARLY
NEXT WEEK. FORECAST CHALLENGE EARLY IN THE EXTENDED WILL BE CENTERED
AROUND TIMING AND INTENSITY OF INITIAL SHORTWAVE IMPULSES EMBEDDED
WITHIN ZONAL FLOW FRIDAY INTO SATURDAY. THEREAFTER GREAT LAKES
WILL BE DOMINATED NORTHWESTERLY UPPER-LEVEL FLOW AND BROAD HIGH
PRESSURE DURING THE FIRST HALF OF NEXT WEEK. BEST OPPORTUNITY FOR
SUBSTANTIAL RAINFALL WILL BE EARLY IN THE PERIOD FOLLOWED BY
MAINLY DRY CONDITIONS AT LEAST THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL START OUT ABOVE NORMAL FRIDAY AND SATURDAY...THEN
FALL BACK TO WELL BELOW NORMAL TOWARD THE MIDDLE PART OF NEXT
WEEK...WITH CHILLY NIGHTS AND POTENTIAL FOR AREAS OF FROST ACROSS
PARTS OF CENTRAL AND NORTHERN WISCONSIN.
INITIAL FORECAST CHALLENGE WILL BE TIMING OF SHOWER AND SCATTERED
THUNDERSTORMS ACTIVITY FRIDAY AFTERNOON AND EVENING WITH
APPROACHING SHORTWAVE IMPULSE...IN CONCERT WITH INCREASING LOW-
LEVEL WAA IN WAKE OF DEPARTING HIGH PRESSURE. WARM ADVECTION
BECOMES QUITE ROBUST BY 00Z SATURDAY AS 850 MB SOUTHWESTERLY WINDS
APPROACH 40 KTS. APPEARS MAJORITY OF LATEST MODEL GUIDANCE ARE A
BIT SLOWER ON INITIAL SHORTWAVE IMPULSE THUS HAVE TRIMMED BACK POPS
ACROSS THE EASTERN HALF OF THE FORECAST AREA IN THE 12Z TO 18Z
TIME FRAME FOR FRIDAY. APPEARS BEST FORCING WILL BE OVER NORTHERN
PORTION OF THE FORECAST AREA LATE FRIDAY AFTERNOON INTO FRIDAY
AND HAVE ADJUSTED POPS ACCORDINGLY. ON FRIDAY NIGHT...THE FORECAST
AREA SHOULD BE BECOME INCREASINGLY UNDER THE INFLUENCE OF THE RRQ
OF AN UPPER LEVEL JET THUS EXPECT GENERAL INCREASE IN ORGANIZED SCALE
SYNOPTIC SCALE LIFT AND DESTABILIZATION AHEAD OF SURFACE COLD
FRONT MOVING INTO CENTRAL MINNESOTA BY 06Z. ALTHOUGH STILL MODEL
DIFFERENCES IN LOCATION OF HEAVIEST QPF OVERNIGHT...ALL GUIDANCE
SUGGEST AN OVERALL INCREASE IN COVERAGE OF SHOWER AND THUNDERSTORM
ACTIVITY.
SATURDAY A BIT MORE UNCERTAIN AS STILL A FAIR AMOUNT OF MODEL
SPREAD ON TIMING OF COLD FRONT ACROSS THE FORECAST AREA. ECMWF
FASTER THAN MOST OF THE OTHER GUIDANCE. OPTED TO LEAN MORE TOWARD
A BLEND OF THE SREF MEAN AND ECMWF WHICH SUGGEST A SOMEWHAT FASTER
PROGRESSION. ADJUSTED POPS ACCORDINGLY WITH LIKELY POPS IN THE
MORNING AND TAPERED TOWARD CHANCE DURING THE AFTERNOON. GIVEN
THIS SCENARIO APPEARS ANY DEEP CONVECTION THAT CAN DEVELOP ALONG
THE COLD FRONT DURING THE AFTERNOON WILL MOST LIKELY OCCUR OVER
THE SOUTHEAST HALF OF THE STATE. IF ECMWF IS CORRECT...SATURDAY
AFTERNOON COULD BE MAINLY DRY. IF ENOUGH CLEARING CAN OCCUR
DAYTIME TEMPS SHOULD BE ABLE TO RESPOND AND RISE WELL INTO THE 70S
AS 850 TEMPS REALLY DO NOT FALL MUCH BEHIND THE COLD FRONT
INITIALLY.
ON SATURDAY NIGHT PRONOUNCED LFQ OF UPPER JET THEN PUSHES INTO
THE AREA WITH PRIMARY SHORTWAVE TROUGH CONTINUING TO DEEPEN OVER
THE AREA. WOULD EXPECT TO SEE SHOWER ACTIVITY INCREASE OVERNIGHT
SATURDAY ESPECIALLY ACROSS THE NORTH. UPPER TROUGH AXIS WILL
PERSIST OVER THE AREA ON SUNDAY WITH CAA CONTINUING. SCENARIO
FAVORABLE FOR AFTERNOON DIURNAL SHOWER ACTIVITY TO DEVELOP OVER
THE NORTHERN PORTION OF THE FORECAST AREA. LEFT SMALL POPS IN FOR
SUNDAY TO ACCOUNT FOR THIS.
HIGH PRESSURE FINALLY BUILDS IN SUNDAY NIGHT AND MONDAY BRINGING A
STRETCH OF DRIER WEATHER INTO AT LEAST MIDWEEK. EXPECT TEMPS TO BE
BELOW NORMAL THROUGH THE FIRST HALF OF THE WEEK WITH POTENTIAL FOR
SOME EARLY MORNING FROST OR FREEZE ESPECIALLY ON TUESDAY MORNING.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 634 PM CDT WED SEP 17 2014
A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE
REGION THIS EVENING. MAINLY A BAND OF VFR MID LEVEL CLOUDS
EXPECTED DURING PASSAGE...WITH A PERIOD OF MVFR CIGS BEHIND THE
FRONTAL BOUNDARY MAINLY OVER THE NORTH. OTHERWISE VFR CONDITIONS
EXPECTED LATE TONIGHT INTO THURSDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 8 AM CDT THURSDAY FOR WIZ010>013-018-
019.
FREEZE WARNING FROM 1 AM TO 8 AM CDT THURSDAY FOR WIZ005.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......TDH
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
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 LITTLE ROCK AR
122 AM CDT THU SEP 18 2014
.AVIATION...18/06Z TAF CYCLE
DENSE FOG HAS DVLPD ACRS N-CNTRL AR...WITH KHRO AND KBPK SEEING
VBSYS AOB 1/2SM. EXPECT THESE CONDS TO PERSIST THRU THE OVERNIGHT
HRS. THE EXCEPTION WL BE IF ANY UPSTREAM CONVECTION ACRS SWRN MO
MANAGES TO AFFECT THESE LOCATIONS...WITH VCTS INCLUDED.
ELSEWHERE...EXPECT TO SEE LOW CLOUDS AND PTCHY BR DVLP THRU THE
EARLY MRNG HRS...WITH OCNL MVFR CONDS THRU MID THU MRNG. CANNOT
RULE OUT ADDITIONAL CONVECTION LATER IN THE DAY...BUT LOW
CONFIDENCE WL PRECLUSE A MENTION IN THE FCST ATTM. /44/
&&
.PREV DISCUSSION... /ISSUED 1208 AM CDT THU SEP 18 2014/
UPDATE...
UPDATED THE FORECAST TO DECREASE RAIN CHANCES OVERNIGHT IN THE
CENTRAL AND EAST SECTIONS. THUNDERSTORMS CONTINUE TO MOVE SOUTH
ALONG THE OKLAHOMA BORDER AND ARE GENERALLY WEAKENING IN ARKANSAS.
ALSO INCREASED CLOUD COVER OVER THE AREA.
PREV DISCUSSION... /ISSUED 149 PM CDT WED SEP 17 2014/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
AREA OF SHRA/TSRA ONGOING ACROSS SRN MO IS BEGINNING TO ACCELERATE
AS THE STRONGEST CELLS ALONG THE WRN HALF OF THIS COMPLEX DROPS SOUTH
INTO AR. SEVERAL OF THE RECENT RUNS OF THE HIGH-RES HRRR HAVE DONE A
REASONABLE JOB ON THESE FEATURES...AND SHOW THIS ACTIVITY DROPPING
GENERALLY SOUTH THROUGHOUT THE AFTERNOON HRS. EXPECTING THIS
ACTIVITY TO GENERALLY FOLLOW THE HIGHER INSTABILITY AXIS ACROSS
THE WRN HALF TO TWO-THIRDS OF THE STATE WHERE MOST UNSTABLE CAPE
VALUES ARE ON THE ORDER OF 1-3K J/KG AT THIS HR. AS A RESULT...DO
HAVE HIGHEST POPS THROUGH MID AFTERNOON OVER THE NRN AND NWRN
SECTIONS OF THE CWA...THEN DROPPING SOUTH TO SW OVER TIME LATER
THIS AFTERNOON. THE HRRR SOLUTIONS EVEN KEEP THIS ACTIVITY GOING
INTO THE SWRN SECTIONS OF THE AREA BY THIS EVENING...SO HAVE
GENERALLY FOLLOWED THIS TREND WITH POPS. HOWEVER...DO DROP POPS
OVER TIME AS UNCERTAINTY IN COVERAGE AN INTENSITY INCREASES BY
LATE THIS EVENING REGARDING THIS ONGOING CONVECTIVE ACTIVITY.
BEYOND THIS EVENING...THE TIMING AND PLACEMENT OF WHAT MAY BE THE
NEXT UPPER DISTURBANCE MOVING OVER THE STATE BECOMES A BIT
UNCERTAIN. EARLIER SHORT TERM MODEL SOLUTIONS HAVE THE NEXT WAVE
MOVING OVER LATE TONIGHT INTO THU MORNING...BUT THIS MAY NOT BE THE
CASE WITH THE ONGOING ACTIVITY AND ITS EXPECTED PATH. THE NEXT WAVE
MAY BE DELAYED A BIT LONGER...BUT MAY ALSO NOT BE AS INTENSE AS
EARLIER EXPECTED. WITH THAT SAID...CONTINUE WITH GENERALLY LOCATION
OF CHANCE POPS FOR MUCH OF THU...BUT HAVE DECREASED POPS SOME AS A
RESULT OF THE UNCERTAINTY OF WHEN/WHERE THE NEXT WAVE MAY MOVE.
BY FRI INTO EARLY SAT...AN UPPER RIDGE WILL MOVE OVER THE
REGION...DECREASING POPS AND INCREASING TEMPS ACROSS THE STATE. BY
LATE IN THE PERIOD THOUGH...HAVE INCREASING POPS WITH THE APPROACH
OF AN UPPER LOW OR THE REMNANTS OF ODILE AS THEY APPROACH FROM THE
WEST/NW.
LONG TERM...SUNDAY THROUGH WEDNESDAY
A COLD FRONT WILL BE MAKING ITS WAY THROUGH THE STATE AT THE START
OF THE LONG TERM...WITH SOME RAIN CHANCES MAKING THEIR WAY INTO THE
AREA THROUGH MONDAY AFTERNOON. THOUGH...LATEST MODEL SOLUTIONS SEEM
LESS AMBITIOUS ABOUT WIDESPREAD RAINFALL IN THE STATE.
AS RAIN CHANCES DISSIPATE BY MONDAY...COOLER AIR WILL FILTER INTO THE
STATE. BOTH HIGH AND LOW TEMPERATURES WILL BE FAIRLY NORMAL TO
SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF SEPTEMBER IN ARKANSAS.
WINDS WILL GENERALLY BE OUT OF THE NORTH THROUGH THE EXTENDED PERIOD
AND A COOL NORTHWEST FLOW ALOFT WILL BE IN PLACE.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1208 AM CDT THU SEP 18 2014
.UPDATE...
UPDATED THE FORECAST TO DECREASE RAIN CHANCES OVERNIGHT IN THE
CENTRAL AND EAST SECTIONS. THUNDERSTORMS CONTINUE TO MOVE SOUTH
ALONG THE OKLAHOMA BORDER AND ARE GENERALLY WEAKENING IN ARKANSAS.
ALSO INCREASED CLOUD COVER OVER THE AREA.
&&
.PREV DISCUSSION... /ISSUED 647 PM CDT WED SEP 17 2014/
AVIATION...
CONVECTION WILL REMAIN ACROSS THE WEST THIS EVENING..AND HAVE VCTS
IN THE TWO WESTERN TAFS THROUGH THE EVENING HOURS. SHORT TERM
GUIDANCE HAS A BREAK IN THE CONVECTION...BEFORE ANOTHER SYSTEM
POTENTIALLY DEVELOPS OVERNIGHT. DUE TO LOW CONFIDENCE...HAVE VCSH
ACROSS THE NORTH. MVFR CONDITIONS WILL DEVELOP ACROSS THE NORTHERN
HALF WITH THE LOW LEVEL MOISTURE OVERNIGHT...AND MAY BECOME IFR.
PREV DISCUSSION... /ISSUED 149 PM CDT WED SEP 17 2014/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
AREA OF SHRA/TSRA ONGOING ACROSS SRN MO IS BEGINNING TO ACCELERATE
AS THE STRONGEST CELLS ALONG THE WRN HALF OF THIS COMPLEX DROPS SOUTH
INTO AR. SEVERAL OF THE RECENT RUNS OF THE HIGH-RES HRRR HAVE DONE A
REASONABLE JOB ON THESE FEATURES...AND SHOW THIS ACTIVITY DROPPING
GENERALLY SOUTH THROUGHOUT THE AFTERNOON HRS. EXPECTING THIS
ACTIVITY TO GENERALLY FOLLOW THE HIGHER INSTABILITY AXIS ACROSS
THE WRN HALF TO TWO-THIRDS OF THE STATE WHERE MOST UNSTABLE CAPE
VALUES ARE ON THE ORDER OF 1-3K J/KG AT THIS HR. AS A RESULT...DO
HAVE HIGHEST POPS THROUGH MID AFTERNOON OVER THE NRN AND NWRN
SECTIONS OF THE CWA...THEN DROPPING SOUTH TO SW OVER TIME LATER
THIS AFTERNOON. THE HRRR SOLUTIONS EVEN KEEP THIS ACTIVITY GOING
INTO THE SWRN SECTIONS OF THE AREA BY THIS EVENING...SO HAVE
GENERALLY FOLLOWED THIS TREND WITH POPS. HOWEVER...DO DROP POPS
OVER TIME AS UNCERTAINTY IN COVERAGE AN INTENSITY INCREASES BY
LATE THIS EVENING REGARDING THIS ONGOING CONVECTIVE ACTIVITY.
BEYOND THIS EVENING...THE TIMING AND PLACEMENT OF WHAT MAY BE THE
NEXT UPPER DISTURBANCE MOVING OVER THE STATE BECOMES A BIT
UNCERTAIN. EARLIER SHORT TERM MODEL SOLUTIONS HAVE THE NEXT WAVE
MOVING OVER LATE TONIGHT INTO THU MORNING...BUT THIS MAY NOT BE THE
CASE WITH THE ONGOING ACTIVITY AND ITS EXPECTED PATH. THE NEXT WAVE
MAY BE DELAYED A BIT LONGER...BUT MAY ALSO NOT BE AS INTENSE AS
EARLIER EXPECTED. WITH THAT SAID...CONTINUE WITH GENERALLY LOCATION
OF CHANCE POPS FOR MUCH OF THU...BUT HAVE DECREASED POPS SOME AS A
RESULT OF THE UNCERTAINTY OF WHEN/WHERE THE NEXT WAVE MAY MOVE.
BY FRI INTO EARLY SAT...AN UPPER RIDGE WILL MOVE OVER THE
REGION...DECREASING POPS AND INCREASING TEMPS ACROSS THE STATE. BY
LATE IN THE PERIOD THOUGH...HAVE INCREASING POPS WITH THE APPROACH
OF AN UPPER LOW OR THE REMNANTS OF ODILE AS THEY APPROACH FROM THE
WEST/NW.
LONG TERM...SUNDAY THROUGH WEDNESDAY
A COLD FRONT WILL BE MAKING ITS WAY THROUGH THE STATE AT THE START
OF THE LONG TERM...WITH SOME RAIN CHANCES MAKING THEIR WAY INTO THE
AREA THROUGH MONDAY AFTERNOON. THOUGH...LATEST MODEL SOLUTIONS SEEM
LESS AMBITIOUS ABOUT WIDESPREAD RAINFALL IN THE STATE.
AS RAIN CHANCES DISSIPATE BY MONDAY...COOLER AIR WILL FILTER INTO THE
STATE. BOTH HIGH AND LOW TEMPERATURES WILL BE FAIRLY NORMAL TO
SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF SEPTEMBER IN ARKANSAS.
WINDS WILL GENERALLY BE OUT OF THE NORTH THROUGH THE EXTENDED PERIOD
AND A COOL NORTHWEST FLOW ALOFT WILL BE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 62 83 63 87 / 10 10 10 10
CAMDEN AR 68 89 69 90 / 20 10 10 10
HARRISON AR 61 80 63 82 / 10 10 10 20
HOT SPRINGS AR 67 85 67 86 / 20 10 10 20
LITTLE ROCK AR 66 86 66 88 / 20 10 10 10
MONTICELLO AR 67 88 68 89 / 20 10 10 10
MOUNT IDA AR 65 84 67 86 / 20 10 10 20
MOUNTAIN HOME AR 60 81 63 84 / 10 10 10 20
NEWPORT AR 61 83 62 87 / 10 10 10 10
PINE BLUFF AR 66 87 66 89 / 20 10 10 10
RUSSELLVILLE AR 65 84 66 86 / 10 10 10 20
SEARCY AR 63 83 64 87 / 10 10 10 10
STUTTGART AR 65 85 64 87 / 20 10 10 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
51
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
400 AM EDT THU SEP 18 2014
...NUMEROUS SHOWERS RETURN TO THE FORECAST FOR FRIDAY...
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A LONGWAVE PATTERN
CONSISTING OF RIDGING OVER MUCH OF THE INTER-MOUNTAIN WEST AND
DOWNSTREAM TROUGHING INTO THE EASTERN STATES. FLORIDA PENINSULA
RESIDES ON THE SOUTHERN PERIPHERY OF THE EASTERN CONUS TROUGH.
IMPULSES ARE MOVING FAIRLY QUICKLY THROUGH THIS PATTERN AND SO THE
FORECAST WILL BE CHANGING QUICKLY AS WELL THROUGH THE NEXT 24 TO 36
HOURS. SHORTWAVE IMPULSE IS NOW PULLING EAST OF THE REGION WITH A
SWATH OF LARGE SCALE SUBSIDENCE AND RESULTING DRY AIR ALOFT NOW
PROGRESSING OVER THE NORTHERN AND CENTRAL PORTIONS OF THE PENINSULA.
THIS MORE SUPPRESSIVE ENVIRONMENT ALLOWED MUCH OF THE REGION TO DRY
OUT DURING THE SECOND HALF OF WEDNESDAY AND CONTINUE TO SEE MAINLY
DRY CONDITIONS EARLY THIS MORNING. ONLY SHOWERS ARE OCCURRING OVER
THE FAR SOUTHERN ZONES/COASTAL WATERS WITHIN A MORE FAVORABLE
MOISTURE COLUMN AND ALONG THE LEFTOVER FRONT/SURFACE TROUGH NOW DOWN
OVER FAR SOUTHERN FL.
AS MENTIONED ABOVE...WITH THE DRIER AIR ALOFT NOW FIRMLY IN PLACE...
SKIES HAVE BECOME MOSTLY CLEAR FOR ALL BUT THE FAR SOUTHERN AREAS
AROUND KFMY. PLENTY OF GROUND MOISTURE FROM THE RAIN ON WEDNESDAY
ALONG WITH A LITTLE SUPPRESSION IS ALLOWING SOME PATCHY GROUND FOG
EARLY THIS MORNING. NOT EXPECTED A WIDESPREAD EVENT...BUT A FEW MORE
FOG PRONE SPOTS MAY BRIEFLY SEE LOWERED VISIBILITIES BEFORE SUNRISE.
&&
.SHORT TERM (TODAY THROUGH FRIDAY)...
WELL...IT CERTAINLY LOOKS AS THOUGH TODAY WILL BE THE BETTER OF THE
TWO SHORT TERM DAYS IN TERMS OF SENSIBLE WEATHER...AS NUMEROUS
SHOWERS RETURN TO THE FORECAST FOR MUCH OF THE AREA FOR FRIDAY.
STARTING OUT THE DAY HERE IN WEST-CENTRAL FLORIDA ON THE BACKSIDE OF
DEPARTING UPPER LEVEL ENERGY...WITH A SWATH OF DRY AIR AND
SUPPRESSION IN PLACE. THIS PATTERN SHOULD KEEP OUR WEATHER MOSTLY
DRY / RAIN FREE THIS MORNING. ONLY EXCEPTION WILL CONTINUE TO BE
DOWN TOWARD LEE/CHARLOTTE COUNTIES WHERE A FEW SHOWERS WILL REMAIN
POSSIBLE...ESPECIALLY CLOSE TO THE COAST. TEMPERATURES WILL RISE
FROM THE UPPER 60S AND 70S AROUND SUNRISE THROUGH THE 80S DURING THE
MORNING.
THIS AFTERNOON...AS A RESULT OF THE LIGHT GRADIENT AND TERRESTRIAL
WARMING...SHOULD SEE A SEA-BREEZE CIRCULATION DEVELOP ON BOTH COASTS
OF THE PENINSULA AND MOVE INLAND. COMING TO THE END OF THE SUMMER
CONVECTION SEASON...BUT LOOKS AS THROUGH THE SEA-BREEZE TODAY WILL
FIND A GOOD ENOUGH ENVIRONMENT TO SUPPORT A FEW SCT STORMS BY THE
LATER AFTERNOON/EARLY EVENING HOURS. THIS SHOULD ESPECIALLY BE TRUE
OVER THE SOUTHERN ZONES AND AWAY FROM THE BEACHES. WOULD BE A BIT
CONCERNED ABOUT WHETHER CONVECTION COULD BE SUSTAINED IF THE CURRENT
UPPER LEVEL ENVIRONMENT WAS GOING TO LAST...BUT LOOKS AS THOUGH WE
WILL BEGIN TO SEE THE COLUMN MOISTEN BY LATER TODAY. AFTERNOON HIGH
TEMPERATURES SHOULD REACH WITHIN A COUPLE DEGREES EITHER SIDE OF 90.
TONIGHT WILL SEE OUR NEXT "WEATHER MAKER" BEGINNING TO APPROACH FROM
THE WEST IN THE FORM OF A DECENT SHORTWAVE TROUGH DIGGING DOWN THE
BACKSIDE OF THE MAIN LONGWAVE TROUGH...AND SPREADING OUR ACROSS THE
NORTHEAST GULF OF MEXICO. AHEAD OF THIS SHORTWAVE...GFS/ECMWF SHOW A
DECENT SWATH OF DEEP LAYER SYNOPTIC SUPPORT / Q-VECTOR CONVERGENCE
OVER THE EASTERN GULF OF MEXICO. IN ADDITION...THE REGION WILL COME
INCREASINGLY UNDER AN AREA OF UPPER LEVEL DIFFLUENCE WITHIN THE
ENTRANCE REGION OF JET ENERGY ALONG THE SHORTWAVE HEIGHT GRADIENT.
THEREFORE...FOR THIS TIME OF YEAR...WE LOOK TO HAVE HEALTHY SYNOPTIC
SUPPORT FOR LIFT. THIS LIFT WILL BE ALIGNED OVER A REGION OF LOWER
LEVEL FOCUS /CONVERGENCE ASSOCIATED WITH THE SURFACE REFLECTION OF
THE ENERGY PASSING ALOFT. WITH ALL THIS IN MIND...SEE LITTLE REASON
WHY NUMEROUS SHOWERS/STORMS WILL NOT BE BREAKING OUT OVER THE
EASTERN GULF DURING THE SECOND HALF OF THE NIGHT AND PROGRESSION
TOWARD THE FL WEST COAST. WILL KEEP THE HIGHEST RAIN CHANCES OFF THE
COAST DURING THE OVERNIGHT...BU DO NOT THINK IT WILL TAKE LONG AFTER
SUNRISE TO SEE THE SHOWERS COMING ASHORE (IF IT WAITS THAT LONG).
FRIDAY IS LOOKING LIKE AN UNSETTLED AND MOSTLY CLOUDY DAY WITH
PLENTY OF SHOWER ACTIVITY. WILL NOT BE RAINING THE WHOLE DAY...BUT
OUTDOOR ACTIVITIES LOOK TO ALMOST CERTAINLY BE IMPACTED. THE SWATH
OF Q-VECTOR CONVERGENCE AND UPPER LEVEL DIFFLUENCE ARRIVE OVER THE
PENINSULA AS THE UPPER LEVEL SHORTWAVE ENERGY AMPLIFIES OVER THE
EASTERN GULF. HAVE RAIN CHANCES QUICKLY INCREASING DURING THE
MORNING HOURS AND REACHING CATEGORICAL LEVELS FOR THE SECOND HALF OF
THE DAY. BEST MOISTURE/SYNOPTIC SUPPORT WILL ALIGN OVER THE CENTRAL
AND SOUTHERN PORTIONS OF THE AREA...HOWEVER...FEEL THE GUIDANCE IS
UNDERDONE OVER THE NATURE COAST...AND HAVE ALLOWED LIKELY POPS EVEN
FOR THESE ZONES. JUST CAN NOT SEE WITH THE ENERGY ALOFT...AND THE
TIME OF YEAR...THAT WE WILL NOT SUPPORT NUMEROUS SHOWERS TO THE
NORTH OF THE I-4 CORRIDOR. WITH ALL THE CLOUDS AND
SHOWERS...TEMPERATURES SHOULD BE HELD DOWN IN THE 80S. IF THE
SHOWERS ARE NUMEROUS ENOUGH AND START EARLY ENOUGH...THEN SOME SPOTS
MAY HAVE TROUBLE GETTING OUT OF THE LOWER 80S.
&&
.LONG TERM (SATURDAY THROUGH NEXT WEDNESDAY)...
THE PERIOD BEGINS WITH AN UPPER TROUGH OVER THE SOUTHEAST U.S. AND
EASTERN GULF WHILE HIGH PRESSURE OFFSHORE NEW ENGLAND SPRAWLS
SOUTHWARD TO THE GULF AND FL...WITH AN INVERTED TROUGH EAST OF THE
STATE. DURING THE WEEKEND A SHORT WAVE TROUGH SLIDES OUT OF CANADA
TO THE GREAT LAKES REGION...DEEPENING AS IT DOES...WITH THE UPPER
TROUGH BECOMING A BROAD CLOSED LOW OVER FL...SPINNING THE SURFACE
TOUGH INTO A LOW EAST OF THE GA/FL COAST. THESE TWO FEATURES TRACK
NORTHEASTWARD TOWARD THE END OF THE WEEKEND AS THE GREAT LAKES
TROUGH BEGINS TO DROP DOWN TO THE GULF COAST.
FOR THE EARLY PART OF NEXT WEEK THE GREAT LAKES-GULF COAST TROUGH
SLIDES OUT OVER ATLANTIC COASTAL WATERS AS DEEP LAYER RIDGING
BUILDS OVER THE MISSISSIPPI RIVER VALLEY THEN MOVES EAST...PUSHING
A FRONTAL BOUNDARY ACROSS THE GULF COASTAL AND SOUTHEASTERN STATES
AND INTO THE EAST GULF AND FL.
THE TROUGHINESS OVER THE WEEKEND FOLLOWED BY THE FRONTAL BOUNDARY
SAGGING IN WILL MAINTAIN A MOIST ATMOSPHERE WITH ISOLATED TO
SCATTERED SHOWERS AND STORMS. THERE WILL BE SOME MINOR VARIATION IN
TEMPERATURES BUT WITHIN A DEGREE OR TWO OF NORMAL.
&&
.AVIATION...
PATCHY FOG HAS DEVELOPED EARLY THIS MORNING ACROSS THE INTERIOR.
HAVE SEEN PROLONGED IFR OR LOWER VISIBILITIES AT KLAL AND THIS IS
LIKELY TO CONTINUE THROUGH SUNRISE. MAY SEE A BRIEF PERIOD OF VIS
RESTRICTIONS AROUND KPGD AS WELL TOWARD DAWN. ONCE ANY EARLY MORNING
FOG BURNS OFF WILL EXPECT PREVAILING VFR CONDITIONS FOR ALL
TERMINALS THROUGH THE DAY. WILL BE A FEW STORMS AROUND TODAY...WITH
THE BEST CHANCES FROM KPGD TO KFMY/KRSW. PREVAILING VFR CONDITIONS
SHOULD CONTINUE INTO THE EVENING HOURS AWAY FROM ANY SCT STORMS.
THEREAFTER...HEADING INTO FRIDAY...NUMEROUS SHOWERS/AREAS OF RAIN
LOOK TO BE IN THE FORECAST FOR ALL TERMINALS...AND LIKELY WILL BE
ACCOMPANIED BY PERIODS OF MVFR RESTRICTIONS.
&&
.MARINE...
A WEAK FRONT IS NOW STALLED SOUTH OF THE FORECAST WATERS WITH A VERY
WEAK GRADIENT IN PLACE OVER THE EASTERN GULF OF MEXICO. THIS WILL
RESULT IN LIGHT WINDS AND SEAS OVER THE WATERS THROUGH THIS EVENING.
WINDS BECOME EASTERLY ON FRIDAY AND MAY INCREASE TO NEAR CAUTIONARY
LEVELS AT TIMES FRIDAY AFTERNOON INTO EARLY SATURDAY...ESPECIALLY TO
THE NORTH OF ENGLEWOOD. IN ADDITION...SHOWERS AND STORMS LOOK TO
ONCE AGAIN BECOME NUMEROUS IN NATURE OVERNIGHT INTO FRIDAY.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE
UPCOMING WEEKEND. RAIN CHANCES WILL BE LOWER TODAY...BUT BECOME
LIKELY ONCE AGAIN FOR FRIDAY.
PATCHY GROUND FOG THIS MORNING WILL BURN OFF WITHIN A FEW HOURS OF
SUNRISE...AND IS NOT EXPECTED TO BE REPEATED TONIGHT INTO FRIDAY
MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 75 84 71 / 30 30 80 30
FMY 90 74 88 72 / 50 30 80 30
GIF 91 73 86 70 / 40 30 80 30
SRQ 89 73 87 71 / 30 30 80 30
BKV 91 71 84 67 / 30 20 70 30
SPG 89 77 84 73 / 30 30 80 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
416 AM EDT THU SEP 18 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF GEORGIA AND SOUTH CAROLINA INTO THE
WEEKEND. A COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...ISOLATED CONVECTION LINGERED ACROSS PARTS OF AREA THROUGH
1 AM BEFORE GATHERING OFFSHORE AND MOVING OUT INTO THE GULF STREAM.
LATEST EMC RAP ANALYSIS INDICATES INCREASING CIN AND NOT MUCH
RESIDUAL INSTABILITY LEFT THUS WE ARE EXPECTING MAINLY DRY WEATHER
FOR DAWN. AREAS OF STRATUS AND FOG WERE DEVELOPING INLAND AND SOME
SPOTS COULD SEE SOME LOCALLY DENSE FOG. AT THIS TIME...NO REGION
TO SINGLE OUT FOR VSBY PROBLEMS...ALTHOUGH SOUTH OF I-16 IN
GEORGIA WILL BE AN AREA TO WATCH.
MID AND UPPER LEVEL TROUGHING CONTINUES THROUGH TONIGHT ACROSS THE
SOUTHEASTERN SEABOARD WITH A POORLY DEFINED SURFACE FRONT CAMPING
OUT ALONG OR SOUTH OF THE SAVANNAH RIVER ENTRANCE. LOW CLOUDS AND
INLAND FOG SHOULD DISSIPATE AFTER MID MORNING WITH WEAK 850 MB
THETA-E ADVECTION FROM W TO E LIKELY TO GENERATE EXPANDING LATE
MORNING AND AFTERNOON CUMULUS/STRATOCU FIELDS. IN ADDITION...UPPER
JET STRUCTURE APT TO DEVELOP SOME HIGHER LEVEL CLOUDS AT TIMES.
CONVECTION PROGNOSIS TODAY POINTS TO AREAS MAINLY ALONG AND E OF I-95
IN SOUTH CAROLINA AS A WEAK LOW PRES REGION IN THE BOUNDARY LAYER
TAKES SHAPE ALONG THE SAVANNAH RIVER THIS AFTERNOON. A WEAK LOBE OF
MID LEVEL VORTICITY IS FORECAST TO TRAVERSE THE CAROLINAS WITH BETTER
THERMODYNAMICS AND MUCAPES PROGGED ALONG THE SEA BREEZE CORRIDOR
NORTH OF SAVANNAH. WHILE MODELS DO NOT SHOW QUITE AS MUCH OVERALL
INSTABILITY AS WEDNESDAY...A FEW STRONGER TSTMS WITH DOWNPOURS AND
FQT LIGHTNING ARE POSSIBLE. WE BUMPED POPS INTO THE CHANCE RANGE
ALONG AND E OF I-95 IN SOUTH CAROLINA THIS AFTERNOON AND ALONG THE
SE GEORGIA COASTAL ZONES EARLY THIS EVENING AS STORMS DRAIN DOWN THE
SEA BREEZE. INTERESTING TO NOTE THAT THE NSSL WRF HINTS AT SOME
DEVIANT/SPLITTING CELLS AGAIN TODAY...SIMILAR TO YESTERDAY. THE
00Z OPERATIONAL NAM APPEARED TO SUFFER FROM CONVECTIVE FEEDBACK AT
TIMES IN THROUGH TONIGHT.
HIGH TEMPS TODAY DEPENDENT ON HOW LONG THE SUN STAYS OUT MANY
AREAS AND WE BUMPED UP TEMPS CLOSER TO 90 SOUTH OF I-16 IN
GEORGIA.
TONIGHT...THERE COULD BE SOME LINGERING CONVECTION ONCE AGAIN WITH
BEACHES AND BARRIER ISLANDS SUSPECT AFTER MIDNIGHT. INLAND AREAS
MAY ALSO SEE YET ANOTHER BOUT OF LOW CLOUDS AND FOG.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...THE CENTER OF SURFACE HIGH PRESSURE WILL STEADILY TRACK
OVER THE NEW ENGLAND STATES DURING THE DAY...THEN OFF THE
NORTHERN COAST THROUGH THE EVENING AND NIGHTTIME PERIOD. THE
MOVEMENT OF THE HIGH WILL ALLOW AN INLAND WEDGE TO STRENGTHEN DOWN
THE APPALACHIANS...STRETCHING FROM THE MID ATLANTIC STATES
THROUGH THE CAROLINAS AND GEORGIA. THIS PATTERN WILL MAINTAIN
SOLID NORTHEAST FLOW ACROSS THE FORECAST AREA...WITH HIGH
TEMPERATURES REFLECTING THE ASSOCIATED COOLING TREND BY ONLY
PEAKING IN THE LOW TO MID 80S. MOISTURE AND CONVERGENCE ALONG THE
PERIPHERY OF THE INLAND WEDGE NEAR A DEVELOPING TROUGH...AS WELL
AS SHORTWAVE ENERGY EMBEDDED WITHIN THE WEAKENING UPPER
TROUGH...WILL STILL BE SUFFICIENT TO SUPPORT SCATTERED CONVECTION.
EXPECT INITIAL ACTIVITY TO BE FOUND OVER THE WATERS AND COASTLINE
DURING THE MORNING...EVENTUALLY SPREADING INLAND THROUGH THE
AFTERNOON HOURS WITHIN ONSHORE FLOW. BEST SHOWER/THUNDERSTORM
COVERAGE WILL THEN RETURN TO THE COASTLINE AFTER SUNSET. LOW
TEMPERATURES WILL CONTINUE TO TREND COOLER...FALLING INTO THE MID
60S INLAND AND UPPER 60S ALONG THE COAST.
SATURDAY...THE UPPER TROUGH ALONG THE EAST COAST WILL BE IN A
DAMPENING STATE LATE IN THE WEEK...EVENTUALLY TRANSITIONING INTO
A BAGGY UPPER LOW FEATURE AT THE START OF THE WEEKEND. ENERGY
WITHIN THIS LOW ALOFT WILL SUPPORT THE STRENGTHENING OF A COASTAL
TROUGH INTO A SURFACE WAVE OF LOW PRESSURE. THERE IS SOME
DISAGREEMENT BETWEEN MODEL SOLUTIONS REGARDING THE STRENGTH OF
THESE FEATURES...WITH CONSENSUS IN ITS GENERAL TRACK TO THE
NORTH/NORTHEAST OVER THE WATERS AS THE DAY PROGRESSES. INLAND
AREAS WITHIN THE WEDGE OF HIGH PRESSURE WILL REMAIN UNDER A DRIER
REGIME...AS THE BEST CHANCE FOR PRECIPITATION IS FOCUSED ACROSS
THE EASTERN HALF OF THE FORECAST AREA CLOSEST TO MOISTURE AND
CONVERGENCE OFFSHORE. HAVE THUS INDICATED SLIGHT CHANCE POPS FAR
INLAND...INCREASING TO 30 TO 40 PERCENT CLOSER TO THE COASTLINE.
RAIN COVERAGE WILL THEN TRANSITION BACK TO THE COASTLINE AND
MARINE ZONES OVERNIGHT. TEMPERATURES WILL BE EVEN COOLER ON
SATURDAY...AS AFTERNOON HIGHS ARE SUPPRESSED IN THE LOW 80S AND
NIGHTTIME MINIMUMS FALL INTO THE MID 60S.
SUNDAY...THE OFFSHORE SURFACE WAVE WILL CONTINUE TO LIFT
NORTH/NORTHEAST ACROSS THE ATLANTIC WATERS...AS THE WEAK UPPER
LOW BECOMES ABSORBED IN A DEEPENING TROUGH TO THE NORTH. THE
INLAND WEDGE WILL STEADILY BREAK DOWN THROUGH THE DAY AHEAD OF A
RAPIDLY APPROACHING COLD FRONT. THE FORECAST AREA COULD BECOME
LOCATED WITHIN A BAND OF DRY DEEP LAYER AIR BETWEEN THE OFFSHORE
LOW TO THE NORTHEAST AND THE COLD FRONT TO THE WEST. HAVE THUS
INDICATED ONLY A SLIGHT CHANCE FOR RAIN ALONG THE
COASTLINE...EXCEPT FOR A SMALL AREA OF CHANCE POPS SOUTH OF
INTERSTATE 16 IN SOUTHEAST GEORGIA. EXPECT MOST
LOCATIONS...ESPECIALLY INLAND...TO OTHERWISE REMAIN DRY.
TEMPERATURES WILL MODERATE UNDER TRANSITIONING SURFACE FLOW WITHIN
THE ERODING INLAND WEDGE...WITH HIGH TEMPERATURES REACHING THE LOW
TO MID 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A STRONG SHORTWAVE TROUGH WILL SWEEP ACROSS THE NEW ENGLAND AND
MID ATLANTIC STATES ON MONDAY...HELPING TO DRIVE A COLD FRONT
THROUGH THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN DECENT
AGREEMENT THAT THE FRONT WILL BE ASSOCIATED WITH LITTLE SIGNIFICANT
PRECIPITATION...AND WILL THUS CONTINUE TO CAP RAIN CHANCES IN THE
SLIGHT CHANCE RANGE DURING FRONTAL PASSAGE. EXPANSIVE SURFACE HIGH
PRESSURE FOLLOWING IN THE WAKE OF THE COLD FRONT WILL HAVE ORIGINS
FROM THE NORTHERN PLAINS STATES...AND WILL BE ACCOMPANIED BY A
MORE NOTABLE CHANGE IN AIR MASS. AHEAD OF THE FRONT...TEMPERATURES
ON MONDAY WILL ACTUALLY WARM SEVERAL DEGREES WITHIN FRONTAL
COMPRESSION AND DOWNSLOPE FLOW. CONDITIONS WILL THEN QUICKLY
COOL...WITH LOW TEMPERATURES MONDAY NIGHT FALLING INTO THE LOW TO
MID 60S. EXPECT HIGH TEMPERATURES TUESDAY THROUGH MID WEEK TO ONLY
PEAK IN THE LOW 80S. NIGHTTIME LOWS WILL RANGE FROM THE LOW TO
MID 60S. WITH DRY HIGH PRESSURE POSSIBLY LINGERING THROUGH THE
EXTENDED PERIOD...HAVE GENERALLY KEPT RAIN CHANCES IN THE SLIGHT
CHANCE RANGE...HIGHEST ALONG THE COAST AND OFFSHORE.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
BOTH SITES HAVE THE POTENTIAL FOR LATE NIGHT STRATUS AND/OR
FOG...WITH MVFR OR LOWER CONDITIONS TO OCCUR FROM AROUND 09-13Z.
WHILE MOST OF THE REST OF THURSDAY WILL BE VFR...ISOLATED
SHRA/TSRA WILL OCCUR IN THE AFTERNOON AND LATER TAF ISSUANCES MAY
NEED TO ADDRESS THE CONCERN FOR IMPACTS ON BOTH OF EITHER
TERMINAL.
EXTENDED AVIATION OUTLOOK...LOW CLOUDS/FOG WILL BE POSSIBLE WITH
PERIODS OF MVFR OR LOWER CIGS EACH MORNING THROUGH AT LEAST
SATURDAY. OTHERWISE...MAINLY VFR OUTSIDE OF ANY ISOLATED SHOWERS
EACH DAY. IMPROVING CONDITIONS WITH MAINLY VFR SUNDAY AND MONDAY.
&&
.MARINE...
FAIRLY STRAIGHTFORWARD FORECAST THROUGH TONIGHT WITH WIND SPEEDS
MAINLY 10 KT OR LESS TODAY BUT INCREASING A BIT IN ONSHORE FLOW
TONIGHT...NOTHING SUBSTANTIAL. SEAS 2 TO 3 FT IN SWELL WAVE FOR
THE MOST PART. SYNOPTIC PATTERN FAVORS SOME NOCTURNAL CONVECTION
OVER THE WATERS AGAIN TONIGHT.
FRIDAY THROUGH MONDAY...MODERATE NORTHEAST FLOW IS EXPECTED
SATURDAY AND SUNDAY...AS PRESSURE GRADIENT REMAINS TIGHT BETWEEN
INLAND HIGH PRESSURE AND A WAVE OF LOW PRESSURE FARTHER OFFSHORE.
WINDS COULD PEAK AT 15 TO 20 KT WITH SEAS 3 TO 5 FEET
SATURDAY...BEFORE DIMINISHING SUNDAY AND MONDAY AS THE INLAND
WEDGE WEAKENS AHEAD OF AN APPROACHING COLD FRONT.
RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES TODAY. DESPITE ONLY LIGHT ONSHORE WINDS...1-2
FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT AN ENHANCED PERIOD
OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND GEORGIA BEACHES. A
MODERATE RISK OF RIP CURRENTS IS THEREFORE IN PLACE TODAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...
SHORT TERM...WMS
LONG TERM...WMS
AVIATION...
MARINE...WMS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1201 AM MDT THU SEP 18 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 143 PM MDT WED SEP 17 2014
WEAK CONVECTION CURRENTLY DEVELOPING IN EASTERN COLORADO ALONG
PALMER DIVIDE AND WEAK WIND CONVERGENT ZONE WILL MOVE INTO
WESTERN KANSAS THIS AFTERNOON. INITIALLY HIGHER BASED CONVECTION
IN KIT CARSON COUNTY WHERE DEWPOINTS ARE IN THE UPPER 30S SHOULD
EVENTUALLY REACH BETTER MOISTURE AS IT WORKS EAST WHERE DEWPOINTS
ARE IN THE LOW-MID 50S. HRRR RUNS ALL MORNING HAVE CONTINUED TO
INDICATE THE POTENTIAL FOR SCATTERED SHRA/TSRA MAINLY SOUTH OF
I-70 IN KANSAS UNTIL EARLY EVENING. NAM HINTS AT THIS AS WELL.
BOTTOM LINE...HAVE INCLUDED LOW POPS TO ACCOUNT FOR THIS BUT FORCING
APPEARS WEAK AND SOME CINH REMAINS TO BE OVERCOME. OVERALL NOT
EXPECTING A BIG CONVECTIVE EVENT HERE.
WIDESPREAD STRATUS AND LOCALLY DENSE FOG IS LIKELY TO DEVELOP OVER
THE EASTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. SURFACE
DEWPOINTS WILL HOLD IN THE UPPER 50S AND LOWER 60S WITH CONTINUED
LIGHT SOUTHEAST BOUNDARY LAYER FLOW.
POTENTIAL EXISTS FOR OVERNIGHT CONVECTION...MAINLY AFTER MIDNIGHT...
EAST OF A TRENTON NEBRASKA TO HOXIE KANSAS LINE. GFS/NAM GUIDANCE
BOTH GIVE SUPPORT TO A SSE-NNW ORIENTED BAND OF SHOWERS AND
THUNDERSTORMS...ALTHOUGH TIMING AND PLACEMENT DIFFERS SOMEWHAT
BETWEEN MODELS. 500-1000 J/KG OF ELEVATED CAPE IS PRESENT TO
SUPPORT CONVECTION IF INHIBITION IS OVERCOME.
TEMPERATURES SHOULD CHANGE LITTLE NEXT COUPLE DAYS AS UPPER RIDGE
OVER THE ROCKIES SHIFTS EAST TO THE CENTRAL HIGH PLAINS. HIGHS
THURSDAY WILL AGAIN BE ABOVE NORMAL AROUND 90F GIVEN FORECAST 850
MB TEMPS 26-30C.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED SEP 17 2014
THURSDAY NIGHT-SATURDAY...FOCUS FOR THIS PORTION OF THE FORECAST IS
THE TRACK OF WHATS NOW WEAKENING TROPICAL STORM ODILE.
DEEP MOISTURE (WITH PRECIPITABLE WATER VALUES AROUND 1.5 INCHES)
ASSOCIATED WITH THE REMNANTS OF THIS SYSTEM ARE FORECAST TO REACH
AREAS SOUTH OF INTERSTATE 70 LATE FRIDAY AFTERNOON...SLIDING SLOWLY
EAST FRIDAY NIGHT AND OUT OF THE AREA EARLY SATURDAY MORNING. THE
GFS IS SLIGHTLY FURTHER SOUTH WITH THE PLUME OF MOISTURE COMPARED TO
THE 12Z NAM/00Z ECMWF...SO NO SLAM DUNK ON PRECIPITATION AMOUNTS
WITH THIS SYSTEM NOR HOW HIGH TO GO WITH POPS. IT APPEARS THAT
EITHER WAY...AS MENTIONED ABOVE...HIGHEST POPS WILL BE ALONG OR
SOUTH OF THE INTERSTATE. SOME LOCALLY HEAVY RAINFALL IS POSSIBLE IF
THE FURTHER NORTH NAM/ECMWF VERIFY.
SOUTH TO SOUTHWEST WINDS FRIDAY MID MORNING THROUGH AFTERNOON
GUSTING IN THE 25-35 MPH RANGE.
FOR SATURDAY AFTERNOON SOME MOISTURE MOVES IN FROM THE NORTHWEST
ASSOCIATED WITH AN UPPER TROUGH PASSAGE. CANT RULE OUT A FEW SHOWERS
AND MAYBE A THUNDERSTORM WITH IT WITH SLIGHT CHANCE POPS AT BEST.
SATURDAY NIGHT...DRY WITH MAYBE SOME HIGH CLOUDS MOVING IN FROM THE
WEST/SOUTHWEST.
LOWS THURSDAY NIGHT MID 50S TO MID 60S WITH SIMILAR...MAYBE A TAD
COOLER READINGS FRIDAY NIGHT.
HIGHS FRIDAY IN THE 80S WITH UPPER 70S TO LOW 80S SATURDAY.
SUNDAY-SUNDAY NIGHT...DRY WEATHER EXPECTED. MID AND HIGH CLOUDS
INCREASE FROM THE SOUTHWEST...ESPECIALLY LATE IN THE AFTERNOON
THROUGH THE NIGHT...AHEAD OF AN UPPER LEVEL LOW PRESSURE AREA MOVING
NORTHEAST TOWARD THE SLC AREA. HIGHS IN THE MID TO UPPER 70S WITH
LOWS IN THE LOW TO MID 50S. WILL BE INTRODUCING SOME SLIGHT CHANCE
TO LOW CHANCE POPS FOR SHOWERS/ISOLATED THUNDERSTORMS FOR THE
WESTERN 1/2 OF THE AREA. HIGH TEMPERATURES MID 70S TO AROUND 80 WITH
LOWS IN THE LOW TO MID 50S.
MONDAY-MONDAY NIGHT...SCATTERED TO BROKEN CLOUDINESS CONTINUES AS
THE UPPER LOW AND ASSOCIATED TROUGH LIFTS NORTHEAST TOWARD EASTERN
WYOMING. WILL NEED TO MAINTAIN SOME LOW CHANCES FOR
SHOWERS/THUNDERSTORMS. HIGHS IN THE LOW TO MID 70S WITH LOWS IN THE
LOW TO MID 50S.
TUESDAY-WEDNESDAY...UPPER LOW AND ASSOCIATED TROUGH FORECAST TO MOVE
EAST/SOUTHEAST TOWARD NORTHEAST NEBRASKA BY THE END OF THE PERIOD.
CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY SLOWLY DECREASING IN
COVERAGE FROM WEST TO EAST WEDNESDAY AS MOISTURE DECREASES FROM WEST
TO EAST WITH PASSAGE OF UPPER TROUGH. HIGHS TUESDAY IN THE LOW 70S
WITH LOW TO MID 70S WEDNESDAY. LOWS TUESDAY NIGHT IN THE LOW TO MID
50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1147 PM MDT WED SEP 17 2014
VFR TO LIFR CONDITIONS FORECAST FOR THE 6Z TAFS. SOUNDINGS FOR
KMCK SHOW A SATURATED LAYER 1.5K FT DEEP. ABOVE THAT LAYER THE
ENVIRONMENT DRIES OUT...WITH BREEZY SOUTHEAST WINDS AT THE TOP OF
THE SATURATED LAYER POSSIBLY MIXING THE DRIER AIR INTO THE
SATURATED LAYER. SEEMS THIS SETUP USUALLY FAVORS STRATUS MORE
THAN FOG...SO WILL KEEP VIS IN THE MVFR CATEGORY. STRATUS SHOULD
CLEAR BY EARLY AFTERNOON FOR KMCK.
FOR KGLD MVFR VIS SEEMS APPROPRIATE GIVEN COLBY IS ALREADY DOWN TO
4 MILES. THERE COULD BE SOME DENSER FOG JUST NORTH OF THE SITE.
HOWEVER WITH MOS NOT FAVORING MORE THAN MVFR RESTRICTIONS AND
SINCE SOUNDINGS FOR KGLD ALSO SHOW BREEZY WINDS AT THE TOP OF THE
SATURATED LAYER...DO NOT BELIEVE THE VIS. SHOULD DROP BELOW 3SM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...99
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1217 AM CDT THU SEP 18 2014
.AVIATION...
FOR THE 18/06Z TAFS...TWO AREAS OF CONVECTION WILL AFFECT THE AREA
EARLY IN THE TAF PERIOD. A BROKEN LINE OF CONVECTION IS MOVING SWD
INTO SE OK/EXTREME SW AR. THIS LINE HAS SHOWN A TENDENCY TO
BACK-BUILD TOWARDS THE WEST SO BELIEVE THESE STORMS WILL REMAIN W
OF KTXK. THESE STORMS HAVE BEEN CYCLING BUT HAVE SHOWN SOME SIGNS
OF DIMINISHING SO CURRENT THINKING IS THEY WILL NOT PERSIST S OF
I-30 BUT CANNOT RULE OF CONVECTION AFFECTING KTYR/KGG LATER THIS
MORNING. FARTHER S...THE ERN EDGE OF A LARGE AREA OF RAIN MAY
AFFECT KLFK FOR A COUPLE OF HRS.
OTHERWISE...LOW CLOUDS AND FOG ARE LIKELY ACROSS MUCH OF THE AREA
ONCE AGAIN THIS MORNING LEADING TO MVFR/IFR FLIGHT CONDITIONS.
IMPROVEMENT BACK INTO THE VFR RANGE IS EXPECTED BY MID TO LATE
MORNING. MORE CONVECTION IS EXPECTED TO DEVELOP AND AFFECT MUCH OF
THE AREA DURING THE DAY THURSDAY. LINGERING FRONTAL BOUNDARY AND
INCREASING MOISTURE/ASCENT FROM THE REMNANTS OF HURRICANE ODILE
MAY ALLOW CONVECTION TO PERSIST LATE INTO THE TAF PERIOD. /09/
&&
.PREV DISCUSSION... /ISSUED 900 PM CDT WED SEP 17 2014/
DISCUSSION...
LOCAL AND REGIONAL RADARS CONTINUE TO SHOW A WELL DEFINED
DISTURBANCE ACROSS EAST CENTRAL OKLAHOMA INTO WEST CENTRAL
ARKANSAS MOVING SOUTH SOUTHWEST IN WEAK NW FLOW ALOFT. THIS
CLUSTER OF STRONG/SEVERE THUNDERSTORMS HAS DEVELOPED A COLD POOL
WHICH IS HELPING TO INITIATE AND SUSTAIN THE CONVECTION EVEN AFTER
SUNSET. LATEST MESOANALYSIS SHOWS CAPE NEAR 2000 J/KG IN OUR
VICINITY OF SE OK INTO SW AR WHICH SUGGESTS THAT THE CONVECTION
SHOULD CONTINUE TO COME SOUTH AT LEAST INTO OUR FAR NW ZONES LATER
THIS EVENING. LATEST HRRR SUPPORTS THIS SCENARIO WITH THE
CONVECTION WEAKENING QUICKLY JUST BEFORE IT MAKE IT TO TXK. FOR
THIS REASON...HAVE RAISED POPS TO CHANCE CATEGORY ACROSS OUR NW
ZONES THIS EVENING.
ELSEWHERE...CONVECTION IS MORE ISOLATED IN NATURE ACROSS NE TX
DESPITE INCREASING MOISTURE ACROSS OUR SW ZONES. PWATS NEAR 2
INCHES EXIST MAINLY TO THE WEST OF A LINE FROM TYR TO THE LOWER
TOLEDO BEND RESERVOIR AND THIS IS WHERE WE WILL CONTINUE TO
ADVERTISE LOW END CHANCE POPS OVERNIGHT. CONVECTION ACROSS CENTRAL
TEXAS ATTM SHOWING NO TENDENCY TO WANT TO MOVE TOWARDS OUR REGION
FROM THE WEST SO LOW END CHANCE POPS ACROSS THIS REGION SHOULD
SUFFICE.
DEWPOINT TEMPERATURES ARE QUITE A FEW DEGREES HIGHER TONIGHT
COMPARED TO 24 HOURS AGO GIVEN AND GIVEN THE INCREASING MOISTURE
FROM THE SOUTHWEST...THIS WILL LIKELY HAVE AN EFFECT ON OUR
TEMPERATURES ACROSS A FEW LOCATIONS. BUMPED OVERNIGHT LOWS UP
ACROSS OUR EASTERN MOST ZONES MAINLY. ELSEWHERE...LOWER 70S SHOULD
SUFFICE EXCEPT FOR UPPER 60S ACROSS OUR EXTREME NW ZONES WHERE
CONVECTION COULD ALLOW TEMPERATURES TO FALL BELOW 70 DEGREES.
OTHERWISE...ALL OTHER FORECAST PARAMETERS ARE IN PRETTY GOOD SHAPE
WITH NO OTHER CHANGES NECESSARY ATTM.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 68 92 70 91 72 / 10 10 10 10 10
MLU 67 92 68 92 69 / 10 10 10 10 10
DEQ 66 88 67 89 68 / 10 10 10 10 30
TXK 67 89 69 90 70 / 10 10 10 10 20
ELD 67 89 67 90 69 / 10 10 10 10 10
TYR 68 89 70 90 72 / 20 10 10 20 20
GGG 67 90 69 91 71 / 20 10 10 10 10
LFK 69 91 70 91 71 / 20 20 10 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 459 AM EDT THU SEP 18 2014
MAIN FCST CONCERN FOCUSES ON CHCS FOR SHRA FRI THRU SUN AS A SERIES
OF SHRTWVS IN A W-NW FLOW MOVE ACROSS THE UPPER GREAT LAKES REGION.
MODELS COMING INTO BETTER AGREEMENT SHOWING THE FIRST IN A SERIES OF
SHORTWAVES MOVING INTO THE NRN PLAINS ON FRI. STRENGTHENING WAA AND
INCREASINGLY MOIST SW FLOW AHEAD OF THIS SHORTWAVE AND ITS ASSOC
TROUGH/FRONTAL BOUNDARY OVER THE NRN PLAINS WILL INCREASE PWAT
VALUES TO 1.5 INCHES OR HIGHER (MORE THAN 180 PCT OF NORMAL) OVER
THE FCST AREA BY FRI AFTERNOON. MODEL SNDGS INDICATE 500-1000 J/KG
OF MUCAPE AND SHOWALTER INDICES DROPPING AS LOW AS -2 TO -4C BY FRI
AFTERNOON/FRI NIGHT SO WOULD EXPECT AN INCREASING POTENTIAL FOR
ELEVATED TSRA AS THE WARM FRONT APPROACHES LATE IN THE DAY. MODEL
CONSENSUS SUGGESTS THE BEST CHC FOR SHOWERS WL BE OVER THE W HALF
OF THE CWA FRI AFTERNOON AND OVER THE E HALF FRI EVNG...WHEN
ISENTROPIC ASCENT/H925-7 MSTR TRANSPORT AND DEEP LAYER Q-VECT CONV
WL BE MAXIMIZED OVER THOSE AREAS. AS FOR TEMPS...INCREASING CLD COVER
WL HOLD DOWN SFC HI TEMPS INTO THE 60S ON FRI DESPITE INFLUX OF MUCH
WARMER AIR. EXPECT RELATIVELY SMALL TEMP FALL ON FRI NGT WITH STRONG
SW FLOW AND INFLUX OF HIGHER PWAT.
SAT...ANOTHER STRONGER SHRTWV APPROACHING FROM SCNTRL CANADA AND THE
NRN PLAINS WILL PROPEL THE SFC LOW PRES TROUGH AND ASSOC COLD FNT
THRU THE UPR LAKES. THERE MAY BE A BETTER CHANCE OF SHOWERS/TS
AGAIN SAT AFTERNOON MAINLY OVER CENTRAL AND ERN COUNTIES AS DYNAMICS
WITH SHORTWAVE LOOK TO BE IN SYNC WITH DAYTIME HEATING AND TIMING OF
COLD FRONTAL PASSAGE. MLCAPES FCST IN EXCESS OF 1000 J/KG WOULD
SUPPORT THUNDER AND WITH DEEP LAYER SHEAR VALUES OF 45-50 KTS A FEW
STRONG TO POSSIBLY SVR STORMS WOULD NOT BE OUT OF THE QUESTION IF
INSTABILITY IS REALIZED. WILL MENTION THIS POTENTIAL IN HWO.
DEPENDING ON HOW QUICKLY THE SFC COLD FNT PASSES ON SAT AND
POTENTIAL BREAKS IN CLOUD COVER...SOME PLACES MAINLY OVER THE CNTRL
CWA COULD SEE TEMPS RISE WELL INTO THE 70S AS H85 TEMPS ARE FCST TO
PEAK AS HI AS 16-17C.
SAT NGT INTO SUN...ALTHOUGH MODELS SHOW TIMING DIFFERENCES...THEY
SEEM TO BE IN AGREEMENT THAT ADDITIONAL SHRTWVS WILL BE DROPPING
INTO THE GREAT LKS THAT ARE FCST TO DEEPEN AN UPR TROF OVER THE
REGION. THE RESULTING NW CYCLONIC FLOW OVER THE AREA ALONG WITH THE
PASSAGE OF A SECONDARY COLD FRONT SHOULD YIELD A GOOD DEAL OF CLD
COVER...PERIODS OF SHOWERS AND COOLER WX AS H85 TEMPS DROP FM AS HI
AS 15C ON SAT AFTN TO AS LO AS 2-4C BY LATE SUN. IT APPEARS
UNLIKELY THAT H85 TEMPS WL FALL ENOUGH TO REALIZE MUCH OF A LK
ENHANCED COMPONENT TO THE CLDS/SHOWERS SUN AND SUN NGT WITH WSHFT TO
THE N GIVEN FAIRLY CHILLY LAKE SUPERIOR TEMPS OF 8-9C.
EXTENDED...WITH HI PRES AND MUCH DRIER AIR MOVING INTO THE GREAT LKS
EARLY NEXT WEEK...EXPECT DRY WX TO PREVAIL FROM MON THRU WED. MON IS
LIKELY TO BE RATHER COOL...BUT RETURN SW FLOW ON THE NW FLANK OF THE
HI SHIFTING TOWARD THE LOWER LKS WL BRING A WARMING TREND TUE THRU
WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 124 AM EDT THU SEP 18 2014
LOW-LEVEL MOISTURE/CLOUDS BEHIND COLD FRONT THAT PASSED YESTERDAY
WILL CONTINUE TO BE AN ISSUE OVERNIGHT AT KSAW. WITH SOME MOISTURE
OFF LAKE SUPERIOR AND NORTHERLY UPSLOPE FLOW...EXPECT LOW CLOUDS TO
PERSIST UNTIL LATE IN THE NIGHT WHEN WINDS VEER MORE EASTERLY OFF
LAND. VFR CONDITIONS WILL THEN BE THE RULE AT KSAW TODAY UNDER A DRY
AIR MASS. AT KCMX...VFR CONDITIONS SHOULD PREVAIL OVERNIGHT...THOUGH
OCNL MVFR CIGS ARE NOT OUT OF THE QUESTION GIVEN SOME CLOUD COVER
STILL OVER LAKE SUPERIOR. A PERIOD OF MVFR CIGS IS MORE LIKELY
TOWARD DAYBREAK AND THRU MID MORNING AS WINDS VEER MORE EASTERLY AND
UPSLOPE OFF THE WARMER WATER OF KEWEENAW BAY. VFR CONDITIONS WILL
THEN PREVAIL LATE MORNING THRU AFTN AT KCMX. AT KIWD...MVFR CIGS
WILL SCATTER OUT OVERNIGHT AS WINDS VEER TO A DOWNSLOPE E TO SE
DIRECTION. VFR CONDITIONS WILL THEN PREVAIL FOR THE REMAINDER OF THE
FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1152 PM CDT Wed Sep 17 2014
.UPDATE:
Issued at 659 PM CDT Wed Sep 17 2014
Noticed some light returns on radar which looked a lot like
drizzle. Sure enough, light drizzle is now occurring here in Weldon
Spring. Looking at NAM X-sections and RAP soundings, seeing a
fairly deep layer of low level moisture between the surface and
about 800mb coincident with weak lift centered around 850mb.
This lift continues though at least 03Z, ending between 04Z-06Z.
Have therefore gone ahead and added patchy drizzle to the forecast
for this evening for most areas east of Columbia and south of
Bowling Green MO/Pittsfield IL.
Carney
&&
.SHORT TERM: (Through Late Tonight)
Issued at 311 PM CDT Wed Sep 17 2014
Old peripheral upper level energy from the MCS that is now pushing
into northern AR will continue to generate isolated-scattered
showers into the early evening before it either weakens too much to
generate anything or it exits our area to the east.
Otherwise, a warm frontal boundary over southeast KS and extreme
southwest MO, which has been nearly stationary due to the MCS rain,
will try to move northeast later tonight and should generate a new
round of SHRA/TSRA over areas mainly to the south and west of STL
metro. Thunder chances up our way look meager enough to leave out
for now.
Clouds are starting to break in southwest IL now and this trend
should continue and even quicken as the upper level energy
generating the showers there comes to an end or exits. This will
leave the leftover low cloud mainly to the west of the MS river and
the light easterly flow will begin to erode the eastern edge of
this, albeit slowly, this evening. By late tonight, though, a
favorable fog/stratus setup along the periphery of the surviving low
cloud in central-southeast MO may actually allow the leftovers to
grow a bit back to the east again.
Went with a more aggressive cooling on the IL side of the river
tonight due to expected clearing, while preferred the warmer MOS in
central MO. In-between, tended to favor the cooler MOS guidance as
well.
TES
.LONG TERM: (Thursday through Next Wednesday)
Issued at 311 PM CDT Wed Sep 17 2014
Surface ridge to continue building in on Thursday. Could see some
lingering light showers over far southern portions of forecast area
in the morning. Otherwise, clouds to clear out from northeast to
southwest with highs in the low 70s. Lows Thursday night will be in
the 50s.
By Friday, surface ridge moves off to the east allowing warmer
southerly flow to return to the region. However, next weather system
to move in on Saturday with showers and thunderstorms possible and
persist through Saturday night before tapering off on Sunday. Highs
on Friday will be in the mid to upper 70s, in the low to mid 80s on
Saturday, then begin to cool back down on Sunday as next ridge of
high pressure builds in.
Cooler weather to persist through the middle of next week with highs
in the 70s and lows in the 40s and 50s.
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1143 PM CDT Wed Sep 17 2014
MVFR flight conditions remain widespread from southwest IL across
eastern MO where they deteriorate to IFR across central and
western MO. Further north where skies cleared earlier, additional
fog and stratus is quickly developing. Conditions should deteriorate
overnight at KUIN and KCOU with dense fog/LIFR flight conditions
expected. For the St. Louis metro terminals I am expecting it to
remain status quo given the current t/td spreads and thus MVFR
flight conditions. All terminals should see improvement beginning
around 15z and then continued rising of ceiling heights and cloud
cover from late morning into the afternoon.
Specifics for KSTL:
Little change expected overnight with MVFR flight conditions
persisting. Anticipating improvement in cig heights beginning
around 15z, and then continued rising of ceiling heights and
reduction in cloud cover from late morning into the afternoon.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
356 AM CDT THU SEP 18 2014
.SYNOPSIS...
ISSUED AT 355 AM CDT THU SEP 18 2014
SURFACE LOW PRESSURE EXTENDS SOUTH FROM ALBERTA CANADA INTO
NEVADA AND WESTERN ARIZONA. SURFACE HIGH PRESSURE CENTER LOCATED
OVER THE NORTHERN GREAT LAKES. STRATUS IS DEVELOPING AND
EXPANDING FROM NWRN KS INTO SWRN NEBR AND THE SOUTHERN NEBRASKA
PANHANDLE EARLY THIS MORNING. PORTIONS OF CENTRAL AND SOUTHWEST
NEBRASKA REPORTING MAINLY LIGHT FOG 3-5SM WITH LOCALLY DENSE FOG
AT THE KBBW ASOS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU SEP 18 2014
NEAR TERM CONCERN IS DEVELOPMENT OF STRATUS AND FOG DEVELOPMENT
ACROSS PORTIONS OF CENTRAL AND SOUTHWEST NEBRASKA. WHILE LOW
VISIBILITY OF 1/4-1/2SM AT KBBW IS POSSIBLE ACROSS THE
AREA...PREVAILING VISIBILITIES SHOULD RANGE FROM 3-5 SM OR
HIGHER. AREAS TO PATCHY FOG IN THE FORECAST UNTIL 15Z.
OTHERWISE...STRATUS IS FORECAST TO QUICKLY EXPAND NORTHWESTWARD
INTO WESTERN NEBRASKA THIS MORNING. MODELS SHOW A NEARLY
SATURATED H9-H85 LAYER PRESENT WITH RELATIVELY DRY AIR ALOFT. THE
STRATUS IS FORECAST TO EXIT MUCH OF THE PANHANDLE BY 18Z...WHILE
POTENTIALLY PERSISTING OVER PORTIONS OF SWRN INTO CENTRAL
NEBRASKA THROUGH THE AFTERNOON. THIS AGREED UPON BY THE NAM AND
06Z RAP MODEL. THE GFS IS LESS AGGRESSIVE WITH CLOUDS WITH MUCH
HIGHER MOS GUIDANCE. USING 00Z SUPERBLEND OUTPUT...BLENDED WITH
THE 00Z MET GUIDANCE TO REFLECT COOLER HIGHS. WHERE CLEARING
OCCURS ACROSS WRN TIER OF COUNTIES...HIGHS IN THE UPPER 80S
ATTAINABLE. MID 70S FORECAST FOR PORTIONS OF CENTRAL AND SERN
ZONES. ALSO INCREASED PERCENT SKY COVER TO REFLECT MOSTLY CLOUDY
SKIES CENTRAL AND SERN ZONES.
STRONG WARM AIR ADVECTION TONIGHT WITH H85 TEMPS UP TO 25C. THIS
WILL CAUSE LINGERING STRATUS THIS EVENING TO QUICKLY LIFT
NORTHEAST AND DISPERSE AFTER 06Z. LOWS TONIGHT WILL BE MILDER
THAN THE PAST SEVERAL NIGHTS RANGING MAINLY IN THE LOWER 60S.
THERE WILL BE A STRONG INVERSION WITH SOUTH WINDS BECOMING
SOUTHWEST LATE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU SEP 18 2014
FRIDAY WILL BE AN UNSEASONABLE WARM DAY AS A LOW DEVELOPS OVER SW
S DAKOTA ALONG A COLD FRONT STRETCHED FROM THE NORTHERN PLAINS
INTO WYOMING. SOUTHERLY WINDS INCREASE AHEAD OF THE FRONT WHICH
SHOULD MIX OUT ANY BL MOISTURE FOG/STRATUS. 850 MB TEMPS INTO THE
20S C AND MOS GUIDANCE WELL INTO THE 80S AND EVEN SOME LOW 90S.
SHOULD SEE SOME A FEW HIGH CLOUDS FROM STORM SYSTEM TO THE SOUTH
SO KEEP HIGHS CONSERVATIVE. COLD FRONT WILL WILL PUSH ACROSS THE
AREA FRIDAY NIGHT INTO SATURDAY. SOME ELEVATED INSTABILITY
OVERNIGHT...WITH AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY. THE ADDED CLOUDS SHOULD KEEP TEMPS
MILD OVERNIGHT.
COOLER BEHIND THE FRONT WITH PRECIP EXPECTED TO BE PUSHING EAST
IN THE MORNING. SOME SUN BEHIND THE FRONT AND TEMPS REBOUND TO
AROUND 80 ON SATURDAY.
COOL HIGH PRESSURE BUILDS IN OVER THE REST OF THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPS TO SLOWLY TREND DOWN THROUGH MONDAY.
MEANWHILE A DISTURBANCE WILL RIDE ALONG THE FRONT RANGE...HOWEVER
MODELS GENERALLY KEEP PRECIP WEST OF THE CWA.
NEXT WEEK THE HIGH SLIDES EAST WITH RETURN SOUTHERLY FLOW TO
BRING A RETURN OF MORE MOISTURE. A DISTURBANCE SHOULD RIDE ACROSS
THE CENTRAL ROCKIES EARLY MONDAY WITH A CHANCE FOR PRECIP LIFTING
ACROSS THE CWA MONDAY INTO TUESDAY. ALTHOUGH 850 TEMPS ON THE
RISE...CLOUDS /ASSOCIATED WITH THE DISTURBANCE/ LIKELY TO KEEP
TEMPS FROM JUMPING UP TO MUCH. GUIDANCE SUGGEST SEASONAL MID
70S...WHICH SEEMS REASONABLE AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1143 PM CDT WED SEP 17 2014
ONCE AGAIN...THE FORECAST ISSUE TONIGHT AND EARLY THURSDAY IS THE
LIKELIHOOD OF CEILING AND/OR VISIBILITY BELOW INSTRUMENT
THRESHOLDS. CONSENSUS AMONG THE SHORT RANGE MODEL OUTPUT IS THAT
INSTRUMENT OR LOW INSTRUMENT METEOROLOGICAL CONDITIONS ARE LIKELY
IN A LARGE PART OF WESTERN NEBRASKA ALONG AND SOUTH-WEST OF A
VTN-ANW-BBW LINE. THOUGH IT MAKES LITTLE DIFFERENCE IN THE FLIGHT
CATEGORY...THE OTHER QUESTION IS...FOG OR STRATUS? CURRENT
INDICATIONS ARE THAT THE WIND SPEED WILL BE 5-10KT AND THAT WOULD
FAVOR LOW STRATUS VERSUS FOG. THEREFORE...OUR CONFIDENCE IS HIGH
THAT CEILING AT OR BELOW 500 FEET AGL WILL DEVELOP AFTER 09Z FOR
MHN...OGA AND LBF AND CONFIDENCE IS NOT HIGH THAT INSTRUMENT
CONDITIONS WILL DEVELOP FOR VTN...TIF AND BBW. FOR THIS FORECAST
ISSUANCE...WE WILL INCLUDE CEILING BELOW 500 FEET AND VISIBILITY
2-3SM FOR LBF AND CEILING JUST ABOVE 1000 FEET AGL AND VISIBILITY
3-5SM FOR VTN. THE LOW CLOUDS WILL BE SLOW TO SCATTER OUT.
CURRENT INDICATIONS FROM SHORT RANGE MODELS AND CONDITIONAL
CLIMATOLOGY WOULD INDICATE SCATTERING BETWEEN 16Z AND 18Z.
THOUGH THIS IS BEYOND THE 24 HOUR FORECAST WINDOW...INSTRUMENT
METEOROLOGICAL CONDITIONS ARE AGAIN POSSIBLE THURSDAY NIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
121 AM EDT THU SEP 18 2014
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH
PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK. THE NEXT
COLD FRONT WILL MOVE THROUGH ON TUESDAY FOLLOWED BY COOL AND DRY
HIGH PRESSURE THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
ISOLATED CONVECTION HAS CONTINUED ACROSS ROBESON COUNTY AND ALSO
JUST OFF THE NEW HANOVER COUNTY BEACHES THIS EVENING. WITH SURFACE
TEMPERATURES NOW 70-74 DEGREES IN MOST LOCATIONS SURFACE-BASED
CAPE IS BELOW 1000 J/KG WITH 20-40 J/KG OF CONVECTIVE INHIBITION
TO DEAL WITH. HOWEVER LIFTING PARCELS FROM 925 MB GIVES ABOUT THE
SAME INSTABILITY WITH NO SIGNIFICANT CAPPING. THIS IS LIKELY THE
SOURCE REGION FOR THE ONGOING SHOWERS AND THUNDERSTORMS. ACTIVITY
APPEARS TO BE FOCUSED ALONG AN INVERTED TROUGH THAT IS THE LEADING
EDGE OF A MODEST NORTHEASTERLY SURGE OVER EASTERN NORTH CAROLINA.
GIVEN THE VERY MOIST AIRMASS UP THROUGH 850 MB THERE IS NO REASON
THIS INVERTED TROUGH/SURGE LINE CANNOT SERVE AS THE FOCUS FOR
ADDITIONAL SHOWERS OR THUNDERSTORMS ALL THE WAY THROUGH THE NIGHT
AS IT MOVES SOUTHWESTWARD THROUGH EASTERN SOUTH CAROLINA. IN
AGREEMENT WITH THE LATEST HRRR (NCEP PARALLEL VERSION) WILL
MAINTAIN 20-30 POPS ACROSS MOST OF EASTERN SOUTH CAROLINA THROUGH
THE NIGHT. THIS MAY HAVE SOME NEGATIVE IMPACT ON THE DEVELOPMENT
OF FOG AND LOW STRATUS LATE TONIGHT...BUT NO SIGNIFICANT CHANGES
WERE MADE TO THAT PORTION OF THE FORECAST. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
CHANGES TO THE FORECAST EARLY THIS EVENING CENTER ON OBSERVED RADAR
TRENDS. CONVECTION IS FINALLY DIMINISHING IN INTENSITY AND COVERAGE
ACROSS THE CAPE FEAR AREA...BUT A RENEWED CLUSTER OF STORMS IS
CROSSING THE SANTEE RIVER WITH ITS SIGHTS SET ON GEORGETOWN IN THE
NEXT HOUR. STORM MOTION IS BEING DRIVEN PRIMARILY BY BOUNDARIES AND
COLD POOL INTERACTIONS...ALTHOUGH A TREND NOTED WITH THE TALLER MORE
SIGNIFICANT THUNDERSTORMS HAS BEEN TO ACCELERATE EASTWARD DUE TO
STRONG WEST WINDS UP ABOVE 600 MB THAT THE SHALLOWER LESS
SIGNIFICANT CONVECTION ISN`T BEING AFFECTED BY. THE SPC MESOANALYSIS
PAGE SHOWS SURFACE-BASED CAPE IS AROUND 1500 J/KG WITH FAVORABLE
MID-LEVEL LAPSE RATES AROUND 6 DEG C/KM.
CONVECTIVE TRENDS THIS EVENING SHOULD BE TOWARD A SLOW DECREASE IN
ACTIVITY AS THE SURFACE COOLS. PLENTY OF DRY AIR ABOVE 700 MB HAS
BEEN HELPING PRODUCE CONVECTIVE OUTFLOW BOUNDARIES DUE TO
ENTRAINMENT INTO DOWNDRAFTS. THE LATEST FEW HRRR RUNS SHOW THERE MAY
BE A FEW LINGERING SHOWERS ACROSS NE SOUTH CAROLINA ROOTED IN A
LAYER OF UNSTABLE AIR AT 950-925 MB PERSISTING AFTER MIDNIGHT. I`LL
KEEP SOME 20 POPS GOING FROM MYRTLE BEACH AND MARION SOUTHWARD
BETWEEN 03-06Z TO ACCOUNT FOR THIS POTENTIAL.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO OTHER FORECAST ELEMENTS.
LOWS SHOULD STILL FALL INTO THE LOWER TO MID 60S FOR MOST AREAS AS
WEAK COOL ADVECTION DEVELOPS OVERNIGHT ON LIGHT NE WINDS BELOW 850
MB. LINGERING LOW-LEVEL MOISTURE WILL ALMOST CERTAINLY CREATE LOW
STRATUS AND FOG LATE TONIGHT...ESPECIALLY INLAND FROM THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE BUILDING DOWN INTO THE
CAROLINAS FROM THE GREAT LAKES ON THURS WILL SHIFT EAST PRODUCING
A VERY PRONOUNCED WEDGE PATTERN BY FRI AFTN. AT THE SAME TIME THE
MID TO UPPER TROUGH OVER THE EAST COAST WILL LIFT OFF TO THE
NORTHEAST. BEFORE THE TROUGH LIFTS OFF...A COUPLE OF MINOR
PERTURBATIONS RIDING AROUND THE BASE MAY ENHANCE CLOUDS AND LOW
END PCP ON THURS...BUT NOT COUNTING ON MUCH. AS TROUGH LIFTS OFF
THROUGH FRI...IT MAY PROVIDE ENOUGH OF A WEAKNESS TO ALLOW
DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST TO RETROGRADE
BACK TO THE W-NW THROUGH FRI NIGHT. OVERALL EXPECT DECENT
NORTHEAST FLOW AS GRADIENT BECOMES MORE PINCHED AS TROUGH OF LOW
PRESSURE SHIFTS NORTH TOWARD THE SOUTHEAST COAST THROUGH LATE FRI
INTO FRI NIGHT. THE NAM HAS THE LOW MOVING FARTHER WEST WITH A
GREATER ON SHORE FLOW OF MOISTURE THROUGH FRI AND A MUCH WETTER
FORECAST...WHILE THE GFS/ECMWF CONFINE THE GREATEST MOISTURE OFF
SHORE AND JUST ALONG THE COAST. FOR NOW WILL GO WITH BRUNT OF CLOUDS
AND POPS OFF SHORE AND JUST ALONG THE COAST IN NE FLOW THROUGH
FRI NIGHT.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN. LOW TEMPERATURES WILL END UP A
LITTLE ABOVE CLIMO DUE TO CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...POTENTIALLY UNSETTLED TO START THE
PERIOD...BUT EVEN BY D4 THERE IS CONSIDERABLE MODEL SPREAD. STALLED
BOUNDARY OFFSHORE WILL BE A FOCUS FOR LOW PRESSURE DEVELOPMENT...BUT
THE QUESTION REMAINS HOW CLOSE TO THE COAST THIS LOW WILL FORM. THE
NAM/CMC ARE IN ONE CAMP WITH DEEP EASTERLY FLOW AHEAD OF A LOW
PRESSURE MOVING RIGHT ALONG THE COAST...CAUSING WIDESPREAD AND
POSSIBLY HEAVY...RAINFALL. THE GFS/ECMWF ARE FURTHER OFFSHORE...WITH
NE FLOW THROUGH THE WEEKEND AS THE LOW PRESSURE STAYS WELL OFF THE
COAST. WPC FAVORING THE ECMWF AND ITS ENSEMBLES...WHICH HAVE
FLUCTUATED LITTLE FROM LAST WEEK...AND THUS WILL CONTINUE WITH THE
INHERITED FORECAST LEANING SIGNIFICANTLY ON THE ECMWF WITH SOME
BLENDING WITH THE WETTER SOLUTIONS. THIS SUGGESTS AT LEAST
WIDESPREAD CLOUD COVER SATURDAY AS THE LOW PRESSURE MAKES ITS
CLOSEST APPROACH...WITH SHOWERS MOST LIKELY ACROSS THE EASTERN
ZONES. IMPROVEMENT WILL OCCUR ON SUNDAY AS THE LOW PRESSURE PULLS
OFF TO THE NORTHEAST...AND TEMPS WILL BE AROUND SEASONABLE THROUGH
THE WKND...ALTHOUGH SUNDAY WILL LIKELY BE A BIT WARMER.
A BRIEF PERIOD OF RETURN FLOW DEVELOPS AHEAD OF A STRONG COLD FRONT
WHICH IS SLATED TO CROSS TUESDAY AFTN. THIS BRINGS A DAY OR TWO OF
WARMER TEMPERATURES...BEFORE CANADIAN HIGH PRESSURE ENVELOPS THE
REGION FOR MID-WEEK. CONVECTION LOOKS LIKELY ON TUESDAY WITH THE
COLD FRONT...AND WILL BUMP POP TO CHC FOR TUESDAY AS SURFACE
CONVERGENCE...PVA...AND SOME JET-LEVEL DIFFLUENCE COMBINE IN A RICH
THETA-E AIR MASS.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...EXPECT IFR/LIFR BR/STRATUS TO DEVELOP AT KFLO AND KLBT
AFTER 09Z WITH LIGHT/CALM WINDS AND DECREASING CLOUD COVER. ALONG
THE COAST...SLIGHTLY STRONGER NORTHEAST FLOW WILL LIKELY KEEP VSBYS
FROM DROPPING BELOW MVFR LEVELS BEFORE 12Z. THERE IS A CHANCE THAT
SOME TEMPO IFR CIGS COULD DEVELOP AT KCRE/KMYR BETWEEN 10-12Z...BUT
CONFIDENCE IS LOW SO WILL KEEP IFR STRATUS SCT ATTM. MVFR CIGS SEEM
MORE LIKELY FOR KILM/KCRE/KMYR JUST AFTER DAYBREAK. PATCHES OF MVFR
CIGS MAY LINGER THROUGH THE LATE MORNING...BUT EXPECT VFR AT ALL TAF
SITES BY MIDDAY. THEN VFR SHOULD PREVAIL THROUGH THE REST OF THE
PERIOD. NORTHEAST WINDS AOB 10 KT WILL BECOME MORE EASTERLY AFTER
18Z. DO NOT ANTICIPATE MUCH...IF ANY...PCPN DURING THE DAY GIVEN THE
DRY AIR ALOFT SEEN IN THE FCST SOUNDINGS.
EXTENDED OUTLOOK...GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS COOL
HIGH PRESSURE EXTENDS SOUTHWARD INTO THE CAROLINAS. EARLY MORNING
MVFR/IFR STRATUS POSSIBLE SAT/SUN MORNING. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
WINDS ACROSS THE COASTAL WATERS NORTH OF CAPE FEAR ARE A LITTLE
STRONGER THAN ANTICIPATED EARLIER. THIS IS LIKELY DUE TO A
TIGHTENING PRESSURE GRADIENT BEHIND A MODEST SURGE LINE/INVERTED
TROUGH THAT IS DROPPING SLOWLY SOUTHWESTWARD ALONG THE COAST. WIND
GUSTS UP TO 21 KNOTS HAVE BEEN MEASURED AT CAPE LOOKOUT AND
WRIGHTSVILLE BEACH WITHIN THE PAST HOUR. NO MODEL HAS WINDS THIS
STRONG CURRENTLY...BUT I HAVE BUMPED WIND SPEED FORECASTS UP TO A
SOLID 15 KNOTS NORTH OF CAPE FEAR...AND 10-15 KNOTS SOUTH OF CAPE
FEAR TO NEAR MYRTLE BEACH. SEAS ARE UP TO A SOLID 4 FEET NORTH OF
CAPE FEAR IN A COMBINATION OF SWELL AND WIND WAVES. PREVIOUS
DISCUSSION FROM 730 PM FOLLOWS...
WEAK LOW PRESSURE WELL OFF THE SC COAST WILL MAINTAIN A LIGHT NE
WIND OVERNIGHT. HIGH PRESSURE NORTH OF THE GREAT LAKES WILL BEGIN TO
RIDGE SOUTHWARD LATE TONIGHT. A SLIGHT NE SURGE TONIGHT WILL
INCREASE WIND SPEEDS UP TO 10 TO 15 KT. EASTERLY SWELL FROM DISTANT
HURRICANE EDOUARD WILL ALLOW SEAS TO BE CONSIDERABLY HIGHER THAN THE
WIND SPEEDS WOULD OTHERWISE INDICATE... 3 TO 4 FT OUTSIDE OF
SHOALING/NEARSHORE INFLUENCES...WITH DOMINANT PERIODS OF 12 TO 13
SECONDS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE RIDGING DOWN FROM THE NORTH
WILL PRODUCE LIGHT NORTHEAST FLOW ON THU AROUND 10 KTS OR LESS. WINDS
WILL WILL INCREASE SIGNIFICANTLY THROUGH FRI AS DISTINCT HIGH
PRESSURE WEDGE SETS UP AND LOW PRESSURE DEVELOPS OFF THE SOUTHEAST
COAST. NE WINDS WILL INCREASE UP TO 20 KT WITH HIGHER GUSTS THROUGH
FRI INTO FRI NIGHT AND MAY BECOME MORE EASTERLY DEPENDING ON
POSITION AND STRENGTH OF DEVELOPING LOW OFF THE SOUTHEAST COAST.
SEAS 2 TO 4 FT ON THURS WILL DIMINISH SLIGHTLY THROUGH THE DAY AS
LONG PERIOD SWELLS DECREASE. AS NE WINDS INCREASE THROUGH FRI...SEAS
MAY REACH SCA THRESHOLDS INTO FRI EVE...ESPECIALLY NORTH OF CAPE
FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT. MAINLY IN
OUTER WATERS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...CONCERN THROUGH THE EXTENDED INVOLVES A LOW
PRESSURE SYSTEM PROGGED TO DEVELOP ALONG A STALLED COLD FRONT OFF
THE COAST. STILL SIGNIFICANT UNCERTAINTY INTO THE STRENGTH AND EXACT
PLACEMENT OF THIS FEATURE...BUT AT LEAST SOME IMPACTS ARE EXPECTED
LOCALLY. THIS LOW PRESSURE WILL MAKES ITS CLOSEST APPROACH TO THE
WATERS ON SATURDAY...PRODUCING ENHANCED NE WINDS OF 15-20
KTS...POSSIBLY HIGHER IF THE LOW IS CLOSER/STRONGER THAN CURRENTLY
FORECAST. WINDS THEN BECOME VARIABLE ON SUNDAY AS A WEAK RIDGE OF
HIGH PRESSURE BUILDS TOWARDS THE AREA...BEFORE TURNING TO THE SW
WIND SW ON MONDAY...WITH SPEEDS RISING BACK TO 10-15 KTS. WAVES WILL
BE PRIMARILY NE-WIND-WAVE DRIVEN ON SATURDAY WITH HEIGHTS 4-5
FT...BUT AGAIN...IF THE SYSTEM IS STRONGER OR CLOSER AN SCA MAY BE
NEEDED. THEREAFTER...WAVE HEIGHTS FALL TO 2-4 FT ON SUNDAY...AND
THEN 1-3 ON MONDAY WITH A SW WIND WAVE AND WEAK SE SWELL FORMING IN
THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...REK/RJD
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...BJR
MARINE...REK/RJD/JDW/RGZ
AREA FORECAST DISCUSSION
NWS NORMAN OK
1200 AM CDT THU SEP 18 2014
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVERNIGHT. LIGHT SOUTH WINDS WILL
BECOME VARIABLE AT KLAW AND KSPS FROM 08Z THROUGH THE MORNING
HOURS. A WEAK FRONTAL BOUNDARY MAY RESULT IN EASTERLY WINDS FOR A
FEW HOURS DURING THE MORNING AT KPNC. WINDS WILL THEN INCREASE AND
SHIFT BACK TO A MORE SOUTHERLY DIRECTION FOR THE REMAINDER OF THE
DAY. SPOTTY SHRA/TSRA MAY DEVELOP FROM I-40 SOUTHWARD...BUT
CONFIDENCE IN IMPACTS TO ANY ONE TERMINAL REMAINS TOO LOW TO
INCLUDE IN TAFS.
&&
.PREV DISCUSSION... /ISSUED 936 PM CDT WED SEP 17 2014/
DISCUSSION...
WILL CONTINUE WITH LOW POPS MAINLY SOUTH OVERNIGHT WITH WEAK
IMPULSE MOVING OUT OF W TX. LATER HRRR RUNS HAVE BACKED OFF ON
ACTIVITY MOVING FROM KS INTO NRN OK OVERNIGHT...BUT WITH
SHOWERS/TSTMS STILL LINGERING IN ERN OK AND SFC BOUNDARY IN THE
AREA WILL ALSO LEAVE LOW POPS MAINLY E OF I-35.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 90 69 88 / 10 30 10 10
HOBART OK 71 91 69 88 / 10 30 10 20
WICHITA FALLS TX 72 91 70 89 / 20 30 20 20
GAGE OK 64 90 66 87 / 0 10 10 20
PONCA CITY OK 70 89 69 89 / 10 20 10 10
DURANT OK 72 89 69 88 / 20 30 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
02/84
AREA FORECAST DISCUSSION
NWS PENDLETON OR
255 AM PDT THU SEP 18 2014
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...AN UPPER LEVEL TROUGH
IS NEAR THE COAST AS IT SLOWLY SHIFTS EASTWARD. THE TROUGH IS
SPLITTING AS IT MOVES INLAND WITH THE NORTHERN SECTION IN WASHINGTON
AND THE SOUTHERN SECTION IN CALIFORNIA. THERE ARE TWO BANDS OF
PRECIPITATION ON RADAR AND MODELS. ONE IS NEAR THE CASCADES ON THE
EAST SIDE OF THE TROUGH AXIS AND THE SECOND ONE IS IN EASTERN GRANT
COUNTY...WALLOWA COUNTY...AND BAKER COUNTY. HRRR SHOWS THE FIRST
BAND REMAINING IN CENTRAL/NORTH CENTRAL OREGON AND CENTRAL
WASHINGTON THIS MORNING. THE SECOND BAND IS ASSOCIATED WITH A JET
STREAK. HRRR SHOWS THIS BAND REMAINING SEPARATE AND MOVING NORTHEAST
OUT OF THE OREGON BY 16Z. THE MORNING FORECAST HAS THE TWO SEPARATE
BANDS...THEN THE FIRST BAND WILL SPREAD ACROSS CENTRAL TO NORTHEAST
OREGON AS THE TROUGH AXIS MOVES ACROSS EASTERN WASHINGTON AND OREGON
THIS AFTERNOON. THE BEST INSTABILITY WILL MOVE FROM CENTRAL TO
NORTHEAST OREGON WHERE THE DIFFLUENCE FROM THE SPLITTING TROUGH IS
ADDED TO THE INSTABILITY AHEAD OF THE TROUGH. ISOLATED THUNDERSTORMS
MAY DEVELOP IN THIS REGION DURING THE AFTERNOON AND EARLY EVENING.
THE TROUGH AXIS WILL BE IN IDAHO BY 6Z/2300 PDT WITH RAIN SHOWERS
ENDING EXCEPT FOR OROGRAPHIC SHOWERS NEAR THE CASCADE CREST. FRIDAY
AND SATURDAY THE UPPER LEVEL RIDGE WILL BUILD OVER THE PACIFIC
NORTHWEST WITH CLEARING SKIES AND WARMING DAYTIME TEMPERATURES.
COONFIELD
.LONG TERM...SUNDAY THROUGH WEDNESDAY...00Z MODEL RUNS INDICATE VERY
SIMILAR SOLUTIONS OVER FORECAST AREA AND NORTHEAST PACIFIC WITH A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUING OVER THE PACIFIC
NORTHWEST SUNDAY AND MONDAY. MODELS SHOW CONSISTENT SOLUTIONS FOR
TUESDAY AS WELL WITH THE RIDGE MOVING EAST INTO THE NORTHERN PLAINS
BY DAYBREAK TUESDAY AS THE NEXT LONGWAVE TROUGH SPREADS EASTWARD TO
130-140W. THE GFS IS MORE PROGRESSIVE IN TAKING THE AXIS OF AN OPEN
LONGWAVE TROUGH TO 132W BY TUESDAY AFTERNOON WHEREAS THE ECMWF KEEPS
THE LOWEST HEIGHTS IN THE OVERALL TROUGH NEAR 140W WHERE A CLOSED
LOW WITH MUCH LOWER HEIGHTS DEVELOPS IN THE ECMWF SOLUTION. BOTH GFS
AND ECMWF SHOW A VERY WEAK DISTURBANCE MOVING THROUGH FORECAST AREA
MONDAY NIGHT AND TUESDAY SO I HAVE INCREASED POPS A TAD TO SLIGHT
CHANCE FOR POSSIBLE ISOLATED LIGHT SHOWERS IN THE BLUE MOUNTAINS
MONDAY NIGHT AND TUESDAY. THE TROUGH APPROACHES THE COAST TUESDAY
NIGHT AND SPREADS INCREASING CLOUDS, MOISTURE, AND RAIN TO THE
CASCADES JUST BEFORE DAYBREAK ON WEDNESDAY. THE PRECIPITATION
SPREADS ACROSS FORECAST AREA WEDNESDAY MORNING. AS ALREADY
MENTIONED, THE GFS IS FASTER IN TERMS OF BRINGING THE TROUGH AXIS TO
THE COAST BY LATE WEDNESDAY MORNING WHILE THE ECMWF KEEPS THE TROUGH
AXIS WELL OFFSHORE. THIS PHASING DIFFERENCE BETWEEN THE TWO MODELS
ON WEDNESDAY WITH RESPECT TO THE PLACEMENT OF THE TROUGH AXIS
RESULTS IN THE ECMWF TAKING LONGER TO SPREAD RAIN TO THE BLUE
MOUNTAINS UNTIL LATE WEDNESDAY NIGHT OR THURSDAY MORNING. AS SUCH
HAVE LOWER CONFIDENCE IN POP FORECAST FOR WEDNESDAY IN THE EASTERN
SECTIONS OF FORECAST AREA. POLAN
&&
.AVIATION...12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NEXT 24 HOURS. THERE MAY BE SOME LIGHT SHOWERS AT
KDLS...KRDM...KBDN...KPDT AND KALW TODAY WITH POSSIBLY A
THUNDERSTORM AT KRDM AND KBDN IN THE AFTERNOON AND EVENING. WINDS
WILL BE GENERALLY LIGHT ALTHOUGH GUSTY AND ERRATIC WINDS ARE LIKELY
NEAR ANY THUNDERSTORMS. CIGS AND VISIBILITIES WILL REMAIN ABOVE VFR
DUE TO THE DRYNESS OF THE AIR MASS IN THE LOWER LEVELS THROUGH THIS
EVENING. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 82 53 80 52 / 20 10 0 0
ALW 83 59 80 57 / 20 10 0 0
PSC 86 57 85 51 / 10 10 0 0
YKM 82 56 84 54 / 30 10 0 0
HRI 84 54 85 48 / 10 10 0 0
ELN 79 57 83 52 / 30 10 0 0
RDM 76 41 79 40 / 20 20 0 0
LGD 82 50 79 44 / 20 20 0 0
GCD 80 49 81 47 / 20 20 0 0
DLS 79 55 83 52 / 30 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
76/99/99
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1249 AM CDT THU SEP 18 2014
.UPDATE...
UPDATED FOR THE 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 948 PM CDT WED SEP 17 2014/
UPDATE...
DECREASED POPS OVERNIGHT DUE TO CURRENT CONDITIONS. STILL
CONFIDENT IN THE HRRR SOLUTION OF SHOWERS IN THE MORNING.
INCREASED CLOUD COVER THROUGHOUT THE DAY TOMORROW TO REFLECT THE
INCREASED MOISTURE ASSOCIATED WITH THE DISTURBANCE APPROACHING THE
AREA.
JPM3
&&
.PREV DISCUSSION... /ISSUED 321 PM CDT WED SEP 17 2014/
NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE MIDSOUTH THROUGH EARLY
FRIDAY. IN THE SHORT TERM... AN MCS OVER NORTHERN AR WILL DRIFT SE
THIS EVENING. UPSTREAM REAR PROPAGATION TENDENCIES THIS EVENING
MAY RESULT IN ADDITIONAL SHOWERS AND THUNDERSTORMS EVENTUALLY
MOVING INTO EASTERN AR AND PERHAPS WEST TN AND NORTHWEST MS
OVERNIGHT.
SHORT TERM MODELS VARY A BIT WITH UPSTREAM CONVECTIVE INITIATION
EARLY ON THURSDAY. GOES WATER VAPOR IMAGERY SHOWED A WEAK SHORTWAVE
MOVING INTO THE WESTERN NEBR PANHANDLE THAT COULD HELP ENHANCE
CONVECTION OVER THE OZARK PLATEAU AND PERHAPS PORTIONS OF THE
MIDSOUTH ON THURSDAY.
BY FRIDAY... AN UPPER LEVEL HEIGHT RIDGE WILL MOVE INTO THE LOWER
MS RIVER VALLEY FROM THE SOUTHERN PLAINS. RESIDUAL MOISTURE FROM
TROPICAL DEPRESSION ODILE WILL OVERRIDE THE TOP OF THE RIDGE...
EVENTUALLY CONSOLIDATING INTO THE BASE OF A NORTHERN BRANCH
LONGWAVE TROF DROPPING INTO TO THE OHIO VALLEY. THIS MOISTURE WILL
MAKE A BRIEF APPEARANCE IN THE MIDSOUTH ON SUNDAY... FOLLOWED BY
DRY NORTHWEST FLOW ALOFT. 12Z ECMWF AND GFS WERE IN GOOD AGREEMENT
FOR THE SUNDAY THROUGH TUESDAY PERIODS.
UPPER HEIGHTS WILL BUILD AGAIN TOWARD THE MIDDLE PART OF NEXT
WEEK...AS THE EASTERN CONUS LONGWAVE TROF LIFTS OUT TO CANADIAN
MARITIMES. A WEAK SLOW MOVING TROF OVER THE SOUTHERN PLAINS WILL
KEEP RAIN CHANCES WELL TO THE WEST...WHILE DRIER LOW LEVELS AND
UPPER RIDGING LIMIT MIDWEEK RAIN CHANCES FOR THE MIDSOUTH.
PWB
&&
.AVIATION...
06Z TAF SET
MODELS INDICATING REDEVELOPMENT OF SHRAS/TSRAS ACROSS SW MO
OVERNIGHT. THUS FAR ONE CELL HAS DEVELOPED BUT IF MORE DOES DEVELOP
THE ACTIVITY COULD PUSH INTO KJBR AROUND 7-8Z...POSSIBLY GETTING TO
KMEM AROUND 9-10Z. WILL CONTINUE MENTION OF VCTS WORDING. CIGS WILL
GRADUALLY LOWER TO MVFR TONIGHT. SOME PATCHY FOG COULD DEVELOP AT
KMKL AS WELL. SHOULD RETURN TO VFR DURING THE MORNING HOURS.
GENERALLY LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.
KRM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1132 PM CDT WED SEP 17 2014
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
SOME ISO LIGHT NOTED ACROSS MID SOUTH...BUT WITH POTENTIAL IMPACTS MINIMAL
IF DEVELOPMENT NEAR TAF SITES...WILL CONTINUE NOT TO MENTION. NWLY FLOW
ALOFT STILL LOOKS LIKE IT WILL SUPPORT PROGRESSION OF MID TO UPPER LEVEL
MOISTURE ACROSS MID STATE THRU 18/12Z...WITH THE POTENTIAL OF CLRING
BEHIND SHORTWAVE PASSAGE NW TO SE...AND ALONG WITH LIGHT TO CALM WINDS...
SUPPORTING MVFR TO IFR FOG TAF SITES THRU 18/14Z. EXPECT DRIER AIRMASS TO
WORK INTO MID STATE THRU 19/01Z WITH DIURNAL SCT CU/SCT CI IN NWLY FLOW
ALOFT. DRY NW FLOW ALOFT/SFC RIDGING SUPPORT SKC/VFR CONDITIONS TILL 19/06Z.
&&
.PREV DISCUSSION.../ISSUED 746 PM CDT WED SEP 17 2014/
DISCUSSION...
IMPULSE WORKING SOUTHEASTWARD ACROSS NORTHERN AR AT THIS TIME. MID
AND HIGH LEVEL CLOUDINESS DOES EXTEND EASTWARD ACROSS THE MID
STATE WITH LOW CLOUDS BACK ACROSS MISSOURI. LATEST HRRR IS
OVERDOING THE CONVECTION FOR THIS EVENING. IN FACT...NO
PRECIPITATION IS INDICATED ACROSS THE MID STATE CURRENTLY.
MODELS DO SHOW...HOWEVER...A RETURN OF MOISTURE AT THE 700 MB TO
850 MB LEVEL TOWARD AND BEYOND 06Z. LIGHT QPF IS HINTED TOWARD BY
THE MODELS AFTER 06Z TONIGHT...MAINLY WESTERN AREAS. THIS IS IN
LINE WITH THE CURRENT ISC THINKING AS WELL. THUS...WILL REMOVE
EVENING PRECIP BUT INCLUDE A 20 PERCENT CHANCE OF SHOWERS FOR
WESTERN AREAS AFTER MIDNIGHT. WILL ALSO INCREASE THE SKY COVERAGE
TO INCLUDE MOSTLY CLOUDY SKIES FOR A LONGER DURATION ACROSS MUCH
OF THE CENTRAL AND WESTERN AREAS.
AS FOR FOG POTENTIAL...TOVER VALUES WILL BE HIGHER AND ARE NEAR
ZERO FOR THE UPCOMING 12Z PERIOD. ALSO...MODELS ARE NOT AS BULLISH
WITH THE LOW DEWPOINT DEPRESSIONS AROUND 12Z AS WELL. WILL
THEREFORE CONTINUE TO LEAVE THE FOG OUT OF THE FCST.
UPDATE OUT SHORTLY.
PREV DISCUSSION.../ISSUED 705 PM CDT WED SEP 17 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
PER MID TO UPPER LEVEL SHORTWAVE PASSAGE EXPECTED ACROSS MID STATE THRU 18/12Z...
ISO LIGHT SHWR DEVELOPMENT POSSIBLE...BUT LOCATION DEVELOPMENT SO UNCERTAIN/VSBY
IMPACTS MINIMAL...SHOULD HAVE LITTLE IF ANY TAF SITE IMPACTS...THUS DID NOT
MENTION. NWLY FLOW ALOFT SHOULD SUPPORT PROGRESSION OF MID TO UPPER LEVEL
MOISTURE ACROSS MID STATE THRU 18/12Z...WITH THE POTENTIAL OF CLRING BEHIND
SHORTWAVE PASSAGE NW TO SE...AND ALONG WITH LIGHT TO CALM WINDS...SUPPORTING
MVFR TO IFR FOG TAF SITES THRU 18/14Z. EXPECT DRIER AIRMASS TO WORK INTO MID
STATE THRU 18/24Z WITH DIURNAL SCT CU AND SCT CI IN NWLY FLOW ALOFT EXPECTED.
PREV DISCUSSION.../ISSUED 218 PM CDT WED SEP 17 2014/
DISCUSSION...
LATEST INFRARED SHOWING TOPS WARMING ALONG ARKANSAS/MISSOURI BORDER
AS COMPLEX CONTINUES TO DIVE SOUTHEASTWARD IN NORTHWESTERLY FLOW ALOFT.
DEBRIS CLOUDS ALREADY SPILLING INTO MIDDLE TENNESSEE THIS
AFTERNOON. I`M NOT COMFORTABLE LEAVING POPS OUT ALTOGETHER FOR
TONIGHT SINCE MID AND UPPER LEVEL SHORT WAVE IS GOING TO WORK
ACROSS OUR AREA DURING THE NIGHT. EURO AND NAM SHOW SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS AS WE THROUGH THE OVERNIGHT.
MET MOS ACTUALLY HAS A 41 POP WHILE MAV MOS HAS 8 AT NASHVILLE FOR
TONIGHT. H-TRIPLE-R BREAKS SHOWERS AND ISOLATED THUNDER OUT AS
WELL TONIGHT. LATEST SREF RUN KEEPS THUNDER WELL WEST OF MY CWA.
NORTHWESTERLY FLOW WILL CONTINUE WEDNESDAY AND THURSDAY WITH UPPER RIDGE
BUILDING IN OVER THE SOUTHERN U.S. BY FRIDAY WITH WESTERLY BELT ALONG
NORTHERN U.S. CANADIAN BORDER. BELT BUCKLES ON SATURDAY AS UPPER RIDGE
BUILDS UP THROUGH THE ROCKY MOUNTAIN REGION WITH A RATHER DEEP TROUGH
BEING CARVED OUT OVER EASTERN U.S INTO MONDAY. THIS WILL ALLOW FOR
A SERIES OF CANADIAN COLD FRONTS TO MOVE DOWN AND THROUGH THE MID
STATE BEGINNING ON SUNDAY. THIS FRONT WILL BE ACCOMPANIED BY SHOWERS
AND A FEW THUNDERSTORMS SUNDAY INTO MONDAY. ANOTHER FRONT ALBEIT
DRY MOVES DOWN ON TUESDAY OF NEXT WEEK ONLY TO REINFORCE THE CONTINENTAL
POLAR AIRMASS THAT`S ALREADY IN PLACE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
416 AM CDT THU SEP 18 2014
.SHORT TERM (TODAY THROUGH FRIDAY)...AREA OF SLOW MOVING SHOWERS
AND THUNDERSTORMS ASSOCIATED WITH SHORTWAVE TROUGH CONTINUES TO
SLOW SAG TO SOUTH THIS MORNING. LATEST HRRR KEEPS THIS ACTIVITY
NORTH OF THE REGION AS THE MORNING PROGRESSES...BUT WILL CONTINUE
TO MONITOR TRENDS WITH THIS COMPLEX. UPPER DISTURBANCE WILL SHIFT
TO THE SOUTHEAST TODAY. THE BEST SUPPORT AND LOW LEVEL CONVERGENCE
WILL REMAIN OVER THE VICTORIA CROSSROADS REGION...AND HAVE PLACED
THE HIGHEST POPS OVER THIS AREA. FURTHER TO THE WEST AND SOUTHWEST
SUFFICIENT MOISTURE WILL REMAIN IN PLACE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS. AS WITH THE LAST SEVERAL DAYS...THREAT
FOR LOCALLY HEAVY RAIN WILL BE POSSIBLE. PW VALUES WILL REMAIN AT
OR ABOVE 2 INCHES TONIGHT INTO FRIDAY. ANOTHER WEAK DISTURBANCE IN
NW FLOW ALOFT WILL MOVE ACROSS CENTRAL TEXAS ON FRIDAY...RESULTING
IN ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. TEMPERATURES
TODAY AND FRIDAY WILL RANGE FROM THE MIDDLE 90S OVER THE RIO
GRANDE PLAINS WITH UPPER 80S TO LOWER 90S OVER THE VICTORIA
CROSSROADS WHERE BETTER CHANCES OF RAIN WILL EXIST.
&&
.LONG-TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...SURFACE HIGH PRESSURE
BEGINS TO NUDGE INTO THE REGION FROM THE NORTHEAST WITH PWATS
EXPECTED TO SLOWLY DECLINE THROUGH THE WEEKEND. NONETHELESS...THERE
WILL STILL BE ENOUGH MOISTURE AVAILABLE TO LEAD TO ISOLATED TO
SCATTERED DIURNAL ACTIVITY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
CONCERNING THE ADVERTISED COLD FRONT NEXT WEEK...MODEL DISAGREEMENTS
CONTINUE. THE NEXT UPPER TROUGH WILL SWING EAST THROUGH THE CENTRAL
PLAINS WITH THE ASSOCIATED FRONTAL BOUNDARY TO FOLLOW. THE ECMWF
KEEPS THE MAIN TROUGH WELL TO THE NORTH WHICH WOULD SUGGEST LITTLE
TO NO AFFECT FROM THE BOUNDARY. HOWEVER THE GFS AND CMC MAINTAIN A
SLIGHTLY SOUTHERN POSITION WHICH WITH THE AIDE OF A SURFACE LOW
ACROSS THE CENTRAL PLAINS...WOULD HELP ELONGATE THE FRONTAL BOUNDARY
INTO SOUTH TEXAS. WITH A MORE NORTH TO SOUTH FLOW IN
MIDLEVELS...WILL CONTINUE TO BRING THE FRONT THROUGH THE REGION
MONDAY NIGHT/TUESDAY KEEPING A SLIGHT CHANCE THROUGH TUESDAY BEFORE
DRYING THINGS OUT FOR THE REST OF THE WEEK. AS FOR
TEMPERATURES...KEPT NEAR TO SLIGHTLY ABOVE GUIDANCE THROUGH THE
PERIOD...WITH THE EXCEPTION OF COOLER CONDITIONS WITH THE FRONTAL
BOUNDARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 91 77 91 76 91 / 30 20 40 20 20
VICTORIA 89 75 91 74 93 / 60 30 50 10 30
LAREDO 96 77 96 78 96 / 20 20 30 20 30
ALICE 94 76 93 74 93 / 20 20 40 10 30
ROCKPORT 89 78 90 78 90 / 30 30 40 20 20
COTULLA 94 76 95 76 96 / 20 30 30 20 30
KINGSVILLE 94 76 93 75 93 / 20 20 40 10 30
NAVY CORPUS 89 80 89 79 91 / 30 20 40 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...SHORT TERM
CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
322 AM CDT THU SEP 18 2014
.SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
&&
.LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING EAST TO WEST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE DISTURBANCE
PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE SFC WILL VEER
TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD FRONTAL PASSAGE
/WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/. THIS COLD FRONT
WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH SUNDAY...WITH A
NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 63 74 61 82 / 60 60 70 60 30
TULIA 78 64 77 63 80 / 40 50 70 60 50
PLAINVIEW 78 64 77 63 80 / 60 60 70 60 50
LEVELLAND 77 65 76 63 81 / 80 70 70 60 40
LUBBOCK 78 67 77 66 81 / 70 70 70 60 50
DENVER CITY 77 66 78 64 84 / 90 70 70 60 40
BROWNFIELD 77 67 78 64 83 / 90 70 70 60 40
CHILDRESS 84 67 83 67 80 / 40 50 50 60 60
SPUR 80 67 80 65 82 / 60 60 50 60 50
ASPERMONT 83 69 85 69 85 / 60 60 50 60 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>030-033>036-039>042.
&&
$$
26/29
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1148 PM CDT WED SEP 17 2014
.DISCUSSION...
SEE AVIATION FOR 06Z TAF DISCUSSION.
&&
.AVIATION...
LIGHT SHRA MOVING BACK INTO NORTHERN TERMINALS THIS EVENING
ASSOCIATED WITH CONVECTION TO THE WEST BETWEEN AUS AND ACT. HAVE
SEEN SOME IFR CIGS AT CXO ALREADY THIS EVENING AND STILL THINK
THERE IS SOME POTENTIAL FOR IFR CIGS AT OTHER SITES...PRIMARILY SGR
AND POINTS CXO NORTHWARD. CONVECTION WILL DEVELOP AGAIN EARLY
THURSDAY MORNING WITH SOME HEAVY RAINFALL POSSIBLE DURING THE DAY.
EXACT TIMING OF IMPACTS TO TERMINALS REMAINS SOMEWHAT PROBLEMATIC
BUT COVERAGE WILL BE BEST FROM LATE MORNING THROUGH LATE
AFTERNOON. 38
&&
.PREV DISCUSSION... /ISSUED 1122 PM CDT WED SEP 17 2014/
..HEAVY RAINFALL AND FLOOD THREAT FOR THURSDAY...
UPDATE...
EVENING FORECAST UPDATE...
DISCUSSION...
MANY AREAS HAVE RECEIVED 1 TO 3 INCHES OF RAINFALL THE LAST
COUPLE OF DAYS. THIS HAS SATURATED GROUNDS AND LOWERED FLASH FLOOD
GUIDANCE. SOME AREAS COULD SEE FLOODING WITH AS LITTLE AS 1-2
INCHES ESPECIALLY IF THAT MUCH FELL IN AN HOUR. RIGHT NOW LOOKS
LIKE A SHORT WAVE TROUGH OVER THE TX PANHANDLE SHOULD TRACK
TOWARDS E TX AND ARKLATEX THUR. LARGE SCALE ASCENT SHOULD INCREASE
OVER TOP A TROPICAL AIRMASS CHARACTERIZED BY PRECIP WATER VALUES
AROUND 2.2-2.4 INCHES WHICH IS WELL SUPPORTED BY LCH/CRP 00Z
SOUNDINGS AND GOES PRECIP WATER PRODUCT. SHORT RANGE HI RES MODELS
SHOW RAIN SHIELD OVER C TX MOVING INTO THE REGION THE NEXT FEW HRS
WHICH COULD DUMP LIGHT RAIN. LATEST RUNS OF HRRR SHOW FURTHER
DEVELOPMENT WITH DAY TIME HEATING DURING THE LATE MORNING HRS.
QUITE POSSIBLE THAT THIS ACTIVITY WILL SET THE STAGE FOR FLOODING
WITH STORMS PRODUCING HIGH RAIN RATES OF 2 INCHES AN HR. LATEST
00Z SHOWS A BROAD BAND OF CONVECTION FORMING ACROSS THE AREA FROM
15Z TO 21Z WITH EMBEDDED HIGHER RAINFALL AMOUNTS. THINK COLLEGE
STATION TO HOUSTON WILL BE THE MAIN AREA OF CONCERN WITH AREAS TO
THE NORTH OF THAT LINE STILL UNDER THE THREAT. COASTAL AREAS HAVE
A LOWER THREAT BUT GIVEN ACCESS TO HIGH MOISTURE AND MESOSCALE
FORCING FROM OUTFLOW BOUNDARIES...NO ONE CAN BE RULED OUT OF THE
HEAVY RAINFALL/FLOOD DISCUSSION. FLOOD WATCH WILL CONTINUE UNTIL
7PM CDT THURSDAY AND DO NOT THINK THERE WILL BE ANY ADJUSTMENTS.
39/38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 84 71 87 71 / 60 80 40 50 20
HOUSTON (IAH) 74 83 71 87 72 / 40 80 40 60 20
GALVESTON (GLS) 79 84 77 85 79 / 40 70 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLOOD WATCH THROUGH THURSDAY EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1122 PM CDT WED SEP 17 2014
...HEAVY RAINFALL AND FLOOD THREAT FOR THURSDAY...
.UPDATE...
EVENING FORECAST UPDATE...
&&
.DISCUSSION...
MANY AREAS HAVE RECEIVED 1 TO 3 INCHES OF RAINFALL THE LAST
COUPLE OF DAYS. THIS HAS SATURATED GROUNDS AND LOWERED FLASH FLOOD
GUIDANCE. SOME AREAS COULD SEE FLOODING WITH AS LITTLE AS 1-2
INCHES ESPECIALLY IF THAT MUCH FELL IN AN HOUR. RIGHT NOW LOOKS
LIKE A SHORT WAVE TROUGH OVER THE TX PANHANDLE SHOULD TRACK
TOWARDS E TX AND ARKLATEX THUR. LARGE SCALE ASCENT SHOULD INCREASE
OVER TOP A TROPICAL AIRMASS CHARACTERIZED BY PRECIP WATER VALUES
AROUND 2.2-2.4 INCHES WHICH IS WELL SUPPORTED BY LCH/CRP 00Z
SOUNDINGS AND GOES PRECIP WATER PRODUCT. SHORT RANGE HI RES MODELS
SHOW RAIN SHIELD OVER C TX MOVING INTO THE REGION THE NEXT FEW HRS
WHICH COULD DUMP LIGHT RAIN. LATEST RUNS OF HRRR SHOW FURTHER
DEVELOPMENT WITH DAY TIME HEATING DURING THE LATE MORNING HRS.
QUITE POSSIBLE THAT THIS ACTIVITY WILL SET THE STAGE FOR FLOODING
WITH STORMS PRODUCING HIGH RAIN RATES OF 2 INCHES AN HR. LATEST
00Z SHOWS A BROAD BAND OF CONVECTION FORMING ACROSS THE AREA FROM
15Z TO 21Z WITH EMBEDDED HIGHER RAINFALL AMOUNTS. THINK COLLEGE
STATION TO HOUSTON WILL BE THE MAIN AREA OF CONCERN WITH AREAS TO
THE NORTH OF THAT LINE STILL UNDER THE THREAT. COASTAL AREAS HAVE
A LOWER THREAT BUT GIVEN ACCESS TO HIGH MOISTURE AND MESOSCALE
FORCING FROM OUTFLOW BOUNDARIES...NO ONE CAN BE RULED OUT OF THE
HEAVY RAINFALL/FLOOD DISCUSSION. FLOOD WATCH WILL CONTINUE UNTIL
7PM CDT THURSDAY AND DO NOT THINK THERE WILL BE ANY ADJUSTMENTS.
39/38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 84 71 87 71 / 60 80 40 50 20
HOUSTON (IAH) 74 83 71 87 72 / 40 80 40 60 20
GALVESTON (GLS) 79 84 77 85 79 / 40 70 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLOOD WATCH THROUGH THURSDAY EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
344 AM CDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERNS TODAY ARE CLOUD TRENDS.
LATEST 08Z SURFACE ANALYSIS SHOWS WEAK COLD FRONT EXTENDING FROM
EASTERN WISCONSIN INTO WESTERN MINNESOTA. LATEST FOG PRODUCT
SATELLITE IMAGERY INDICATES LOW LEVEL STRATUS OVER PORTIONS OF
NORTHERN AND EASTERN HALF OF WISCONSIN AND EAST CENTRAL
MINNESOTA. THIS LOW LEVEL STRATUS IS MOVING SOUTH AND WEST BEHIND
THE WEAK SURFACE FRONT.
THE 18.00Z GFS/NAM AND 18.06Z RAP APPEAR INITIALIZE AND HANDLE
MOVEMENT/EXPANSION OF LOW LEVEL STRATUS WELL INTO WESTERN WISCONSIN
EARLY THIS MORNING/TODAY PER THE 925MB RELATIVE HUMIDITY FIELDS. THE
BIG QUESTION WILL BE HOW LONG WILL THE LOW LEVEL STRATUS HANGS
AROUND THE FORECAST AREA TODAY. THE 18.00Z GFS/NAM AND 18.06Z RAP
SUGGEST THE CLOUDS WILL ERODE DUE TO DAYTIME HEATING AND LIFT BACK
NORTH INTO NORTHERN WISCONSIN AROUND 18Z TODAY. IF LOW LEVEL STRATUS
ERODES LATER IN THE AFTERNOON...THIS WILL HAVE IMPACTS ON FORECAST
HIGH TEMPERATURES FOR TODAY...ESPECIALLY OVER EASTERN PART OF THE
FORECAST AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY INTO SATURDAY
NIGHT. THE LATEST 18.00Z GFS/NAM/ECMWF SHOW DECENT ISENTROPIC LIFT
AT 305K SURFACE BETWEEN 12-18Z FRIDAY AND ASSOCIATED 925-850MB
MOISTURE TRANSPORT INTO THE WESTERN FORECAST AREA. THE COMBINATION
OF ELEVATED INSTABILITY OF 0-6KM MOST UNSTABLE CAPE OF 300-800
J/KG OVER THE WESTERN FORECAST AREA AND THIS LIFT...WARRANTS A
SMALL PRECIPITATION CHANCE OVER THE WESTERN FORECAST AREA BETWEEN
12-18Z FRIDAY.
AFTER THIS INITIAL WEAK IMPULSE IN ASSOCIATION WITH WARM AIR
ADVECTION...THE 18.0ZZ GFS/NAM/ECMWF INDICATE MUCH OF THE
SOUTHERN FORECAST AREA BECOMES CAPPED AFTER 18Z FRIDAY...AS
SHORTWAVE RIDGE BUILDS INTO THE AREA AND FOCUSES LIFT/MOISTURE
TRANSPORT INTO NORTHERN WISCONSIN. HAVE ADJUSTED PRECIPITATION
CHANCES FURTHER NORTH AFTER 18Z FRIDAY. THE CAP BEGINS TO WEAKEN
AFTER 00Z SATURDAY ACROSS THE FORECAST AREA...IN ADDITION SURFACE
FRONT PUSHES ACROSS FORECAST AREA AND DEEP FORCING/MOISTURE
TRANSPORT/CONVERGENCE WILL ALLOW SHOWERS AND THUNDERSTORMS TO
DEVELOP IN THE 00-06Z SATURDAY TIMEFRAME AND MOVE NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT. ANY SEVERE THREAT
WITH THE THUNDERSTORMS LOOKS TO BE CONFINED NORTH OF THE
INTERSTATE 90 CORRIDOR...WHERE THE BETTER INSTABILITY AND SHEAR
WILL BE OVER THE FORECAST AREA. AT THIS TIME...THE SEVERE THREAT
LOOKS TO BE ISOLATED AND THE MAIN THREATS WOULD BE LARGE HAIL AND
DAMAGING WINDS.
SURFACE FRONT/SHORTWAVE TROUGH PUSHES SOUTH AND EAST OF FORECAST
AREA SATURDAY AND TAKING THE BULK OF LIFT AND BETTER INSTABILITY
SOUTH AND EAST OF FORECAST AREA. THE REGION WILL BE UNDER THE
INFLUENCE OF CYCLONIC FLOW SATURDAY...WITH STEEPENING LAPSE RATES
AND A COUPLE HUNDRED ELEVATED CAPE PER BUFKIT SOUNDINGS. SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ACROSS THE FORECAST
AREA. HAVE LEFT SMALL PRECIPITATION CHANCES IN THE FORECAST.
UPPER LEVEL TROUGH BEGINS TO BREAK DOWN OVER THE GREAT LAKES
REGION AND HEIGHTS RISE OVER THE NORTHERN PLAINS LATE SUNDAY INTO
THE MIDDLE OF NEXT WEEK. THE 18.00Z GFS/ECMWF ARE INDICATING
UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES BY 00Z
THURSDAY. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL EARLY TO
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED SEP 17 2014
SATELLITE AND SURFACE OBSERVATIONS THIS EVENING INDICATE THE
STRATUS CLOUDS HAVE ADVANCED INTO NORTHERN WISCONSIN BUT ARE
MOVING SOUTH A SLOWER PACE THAN EARLIER EXPECTED. THE 18.00Z NAM
NOW SUGGESTS THESE CLOUDS WILL NOT MAKE INTO THE AREA BEFORE SOME
FOG CAN FORM AND THIS IS CONSISTENT WITH WHAT THE RAP HAS BEEN
SHOWING ALL EVENING. BASED ON THESE TRENDS HAVE GONE FOR A VALLEY
FOG EVENT AT KLSE WITH IFR CONDITIONS DEVELOPING AND PERSISTING
THROUGH THE MIDDLE OF THURSDAY MORNING BEFORE LIFTING. WITH A DEEP
LAYER OF LIGHT WINDS...SHOULD ALSO SEE SOME FOG FORM AT KRST WITH
MVFR/IFR VISIBILITIES EXPECTED. ONCE THE FOG LIFTS THURSDAY
MORNING...VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF THE
PERIOD AS HIGH PRESSURE DRIFTS ACROSS THE NORTHERN GREAT
LAKES/SOUTHERN ONTARIO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 318 PM CDT WED SEP 17 2014
AS OF MID AFTERNOON...WATER VAPOR IMAGERY COMBINED WITH 500 MB
RAP HEIGHTS SHOWED LONGWAVE TROUGHING OVER THE GREAT LAKES REGION
WITH SUBTLE SHORTWAVE MOVING THROUGH NORTHERN WISCONSIN. TO THE
WEST...THE REMNANTS OF OLDIE ARE LAID OUT ACROSS SOUTHWEST CONUS
IN THE MIDST OF A LARGE SCALE RIDGE OVER THE INTERMOUNTAIN WEST.
AT THE SURFACE...BACKDOOR COLD FRONT LIES FROM THE BOUNDARY
WATERS REGION OF NORTHERN MINNESOTA THROUGH THE U.P. OF
MICHIGAN...DENOTED BY NORTHEASTERLY FLOW AND LOW STRATUS IN ITS
WAKE. IT IS THIS FEATURE THAT WILL BE THE NEAR/SHORT TERM FORECAST
CONCERN.
17.12Z GUIDANCE IN REASONABLE AGREEMENT SHOWING THE FRONT
ADVANCING SOUTHWESTWARD TONIGHT...REACHING THE I-94 CORRIDOR OF
CENTRAL WISCONSIN AFTER MIDNIGHT. 925 TO 850 MB RH FIELDS SUPPORT
STRATUS DECK CONTINUING ITS MARCH...HOLDING UP JUST ALONG AND EAST
OF THE MS RIVER BY SUNRISE THURSDAY. INCREASED OVERNIGHT SKY COVER
QUITE A BIT ACROSS WEST CENTRAL WISCONSIN. TEMPERATURES DO FALL
OFF WITH ITS PASSAGE...SO STILL LOOKING AT LOWS IN THE UPPER 30S
FOR THOSE AREAS DESPITE CLOUD COVER.
THE REST OF THE FORECAST AREA WILL BE COMPLICATED BY FOG AND/OR
DEVELOPING STRATUS POTENTIAL OVERNIGHT. WIND PROFILES FROM
KLSE/KRST/KDEH AHEAD OF THIS FRONT ARE VERY LIGHT THROUGH
09Z...LESS THAN 10 KTS UP TO 700 MB...THOUGH BEGIN TO INCREASE
BETWEEN 09-12Z. ENVISION INITIALLY PATCHY TO MAYBE AREAS OF FOG
CONCENTRATED IN THE MS AND WISCONSIN RIVER VALLEYS/TRIBS BUT ALSO
GUIDANCE SUGGESTS PATCHY FOG IS POSSIBLE ACROSS NORTHEAST IOWA AND
SOUTHEAST MINNESOTA. AS WINDS AT BLUFF TOP INCREASE...FOG SHOULD
DISSIPATE AND BECOME BROKEN STRATUS. 17.12Z HI-RES MODELS AND SREF
PROBABILITIES SUGGEST THIS THINKING AS WELL.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 PM CDT WED SEP 17 2014
FOCUS IN THIS PERIOD IS ON SHOWER/STORM CHANCES FRIDAY AND
SATURDAY AS WEATHER SYSTEM PASSES THROUGH THE UPPER MIDWEST. BRIEF
UPPER LEVEL RIDGING FRIDAY BECOMES ZONAL FRIDAY AFTERNOON AS
SHORTWAVE TRAVERSES NORTHERN PLAINS. THERE COULD BE SOME FRIDAY
MORNING WARM AIR ADVECTION SHOWERS WEST OF THE MS RIVER BUT IS
LIKELY TO BE WEST OF THE FORECAST AREA. AS THE CAP
STRENGTHENS...THIS WILL SHUT OFF AND/OR MOVE PRECIP TO THE
NORTHEAST. THE BULK OF THE AREA WILL BE CAPPED OFF FRIDAY AS PLUME
OF WARM 700 MB AIR /+12C/ OFF THE HIGH PLAINS NOSES INTO THE UPPER
MIDWEST. THE GFS/NAM ARE AGGRESSIVE WITH THIS CAP...SHUTTING OFF
ANY PRECIP CHANCE DURING THE DAY UP TO KMSP/KEAU AREAS. STRONG
SOUTHERLY FLOW WILL MAKE FOR A BREEZY DAY...ESPECIALLY ACROSS OPEN
AREAS OF SOUTHERN MN. WIND GUSTS 25 TO 35 MPH LIKELY LATE MORNING
THROUGH AFTERNOON.
FINALLY BY FRIDAY EVENING SOME COOLING AND FALLING HEIGHTS WITH
SHORTWAVE TROUGH MOVING THROUGH SHOULD HELP TO BREAK CAP AND ALLOW
CONVECTION TO DEVELOP ACROSS CENTRAL MINNESOTA TO NORTHWEST
WISCONSIN. SHEAR PROFILES ARE IMPRESSIVE NOTED BY 0-6 KM BULK
VALUES 30+ KTS WITH SOME CURVATURE IN THE HODOGRAPHS IN THE
LOWEST 3 KM. AT THE SAME TIME...WARM CLOUD DEPTHS ARE 3.5 TO 4.0
KM...WHICH WILL LIMIT HIGHER HAIL THREAT BUT AID IN THE HEAVY RAIN
PRODUCTION. INITIATION LOOKS TO BE CENTRAL MINNESOTA TO NORTHWEST
WISCONSIN...THEN TRACK EAST/SOUTHEAST THROUGH THE NORTHERN HALF OF
THE FORECAST AREA LATE FRIDAY EVENING. THE BULK OF THE ACTIVITY
LOOKS TO BE IN THE 03-12Z TIME FRAME. SOME STRONGER TO SEVERE
STORMS ARE POSSIBLE INITIALLY...MAINLY DAMAGING WINDS AND HEAVY
RAIN. MARGINAL SEVERE HAIL THREAT. THE GREATEST THREAT IS NORTH
OF I-90.
STILL SOME TIMING DIFFERENCES BETWEEN 17.12Z GUIDANCE BUT COLD FRONT
SHOULD SLIP THROUGH 12-18Z ACROSS MUCH OF THE AREA. AHEAD OF
IT...WEAK CAP REMAINS IN THE PLACE WHICH COULD LIMIT COVERAGE OF
SHOWERS/STORMS WITH THE HIGHER CHANCES LOOKING TO BE NORTHEAST
IOWA INTO SOUTHWEST WISCONSIN.
COOL CANADIAN HIGH PRESSURE THEN LOOKS TO BUILD IN SUNDAY THROUGH
WEDNESDAY PROVIDING THE UPPER MIDWEST WITH SEVERAL
PLEASANT...SEASONABLY COOL DAYS. HIGHS IN THE MIDDLE/UPPER 60S AND
LOWS IN THE 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED SEP 17 2014
SATELLITE AND SURFACE OBSERVATIONS THIS EVENING INDICATE THE
STRATUS CLOUDS HAVE ADVANCED INTO NORTHERN WISCONSIN BUT ARE
MOVING SOUTH A SLOWER PACE THAN EARLIER EXPECTED. THE 18.00Z NAM
NOW SUGGESTS THESE CLOUDS WILL NOT MAKE INTO THE AREA BEFORE SOME
FOG CAN FORM AND THIS IS CONSISTENT WITH WHAT THE RAP HAS BEEN
SHOWING ALL EVENING. BASED ON THESE TRENDS HAVE GONE FOR A VALLEY
FOG EVENT AT KLSE WITH IFR CONDITIONS DEVELOPING AND PERSISTING
THROUGH THE MIDDLE OF THURSDAY MORNING BEFORE LIFTING. WITH A DEEP
LAYER OF LIGHT WINDS...SHOULD ALSO SEE SOME FOG FORM AT KRST WITH
MVFR/IFR VISIBILITIES EXPECTED. ONCE THE FOG LIFTS THURSDAY
MORNING...VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF THE
PERIOD AS HIGH PRESSURE DRIFTS ACROSS THE NORTHERN GREAT
LAKES/SOUTHERN ONTARIO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
332 AM MDT THU SEP 18 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM MDT WED SEP 17 2014
WYOMING TAFS...VFR PREVAILS.
NEBRASKA TAFS...AREAS OF IFR DEVELOPING THROUGH 15Z...OTHERWISE
VFR PREVAILS.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
906 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF RAIN
SHOWERS TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH
AND IN COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL
AVERAGES TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND
SATURDAY. DRY CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT
PACIFIC WEATHER SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD
MIDWEEK.
&&
.DISCUSSION...AS OF 08:52 AM PDT THURSDAY...RAIN SHOWERS CONTINUE
TO MOVE ACROSS THE REGION WITH THE MID/UPPER LEVEL TROUGH
CURRENTLY PUSHING INTO NORTHERN CALIFORNIA. CANNOT RULE OUT A
THUNDERSTORM OR TWO OVER THE NORTH BAY THIS AFTERNOON WITH A
NEARLY 90KT UPPER LEVEL JET AND SHORT-WAVE MOVING ACROSS THE
REGION. PRECIPITATION CHANCES DIMINISH BY TONIGHT AS THE UPPER LEVEL
SUPPORT SHIFTS SOUTHWARD AND THE TROUGH MOVES FURTHER INLAND. THE
ONGOING FORECAST REFLECTS OUR LATEST ANALYSIS AND NO UPDATES ARE
EXPECTED AT THIS TIME.
AS OF THIS MORNING...THE SANTA CRUZ MOUNTAINS HAVE RECEIVED THE
MOST PRECIPITATION WITH AMOUNTS UPWARDS OF 0.60" DURING THE PAST
12 HOURS. NORTH BAY MOUNTAIN LOCATIONS HAVE REPORTED BETWEEN 0.25"
AND 0.50" WHILE AMOUNTS UP TO 0.25" FELL OVER PORTIONS OF THE
SANTA LUCIA MOUNTAINS DURING THE SAME TIME FRAME.
&&
.PREV DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 4:55 AM PDT THURSDAY...SCATTERED RAIN SHOWERS
WILL CONTINUE THROUGH A LEAST MIDDAY TODAY AS A LOW PRESSURE
SYSTEM SLIDES SOUTH ALONG THE COAST. SHOWERS WILL GRADUALLY TAPER
THIS AFTERNOON INTO THE EVENING. MVFR EXPECTED THROUGH MUCH OF THE
DAY WITH LOW CLOUDS ANTICIPATED TO RETURN THURSDAY EVENING. LIGHT
TO MODERATE WINDS WILL PERSIST THROUGH THE FORECAST PERIOD.
MODERATE TO HIGH CONFIDENCE.
VICINITY OF KSFO...LIGHT DRIZZLE HAS FALLEN UPON AREA TERMINALS
OVERNIGHT RESULTING IN WET RUNWAYS THIS MORNING. SCATTERED
SHOWERS POSSIBLE THROUGH THE DAY. MVFR CIGS WILL LIFT THIS
AFTERNOON WITH TEMPO SCATTERING POSSIBLE. LOW CLOUDS EXPECTED TO
RETURN AROUND 06Z-07Z TONIGHT. WINDS WILL REMAIN LIGHT THROUGH THE
MORNING THEN EXPECTED TO STRENGTHEN IN THE AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR TO VFR CIGS ANTICIPATED TO
PERSIST THROUGH TODAY WITH SCATTERED SHOWERS POSSIBLE. IFR CIGS
FORECAST TO RETURN AFTER 06Z TONIGHT. LIGHT WINDS WILL STRENGTHEN
TO AROUND 10 KT IN THE AFTERNOON.
&&
.MARINE...AS OF 2:55 AM PDT THURSDAY...A LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL IMPACT THE WATERS THROUGH THIS EVENING. A
LOW CENTERED APPROX 435 NM DUE WEST OF POINT ARENA WILL MOVE
THROUGH THE NORTHERN WATERS TODAY RESULTING IN LIGHT SOUTHERLY
WINDS AND SCATTERED SHOWERS. THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS NORTH OF POINT REYES AND IN THE SAN FRANCISCO BAY
THIS AFTERNOON. WINDS WILL BECOME LIGHT TO MODERATE NORTHWEST
FRIDAY THROUGH SUNDAY AFTER THE LOW MOVES INLAND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RG/KBB
AVIATION/MARINE: CW
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
509 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF LIGHT
RAIN TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH AND IN
COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL AVERAGES
TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND SATURDAY. DRY
CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT PACIFIC WEATHER
SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD MIDWEEK.
&&
.DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 4:55 AM PDT THURSDAY...SCATTERED RAIN SHOWERS
WILL CONTINUE THROUGH A LEAST MIDDAY TODAY AS A LOW PRESSURE
SYSTEM SLIDES SOUTH ALONG THE COAST. SHOWERS WILL GRADUALLY TAPER
THIS AFTERNOON INTO THE EVENING. MVFR EXPECTED THROUGH MUCH OF THE
DAY WITH LOW CLOUDS ANTICIPATED TO RETURN THURSDAY EVENING. LIGHT
TO MODERATE WINDS WILL PERSIST THROUGH THE FORECAST PERIOD.
MODERATE TO HIGH CONFIDENCE.
VICINITY OF KSFO...LIGHT DRIZZLE HAS FALLEN UPON AREA TERMINALS
OVERNIGHT RESULTING IN WET RUNWAYS THIS MORNING. SCATTERED
SHOWERS POSSIBLE THROUGH THE DAY. MVFR CIGS WILL LIFT THIS
AFTERNOON WITH TEMPO SCATTERING POSSIBLE. LOW CLOUDS EXPECTED TO
RETURN AROUND 06Z-07Z TONIGHT. WINDS WILL REMAIN LIGHT THROUGH THE
MORNING THEN EXPECTED TO STRENGTHEN IN THE AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR TO VFR CIGS ANTICIPATED TO
PERSIST THROUGH TODAY WITH SCATTERED SHOWERS POSSIBLE. IFR CIGS
FORECAST TO RETURN AFTER 06Z TONIGHT. LIGHT WINDS WILL STRENGTHEN
TO AROUND 10 KT IN THE AFTERNOON.
&&
.MARINE...AS OF 2:55 AM PDT THURSDAY...A LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL IMPACT THE WATERS THROUGH THIS EVENING. A
LOW CENTERED APPROX 435 NM DUE WEST OF POINT ARENA WILL MOVE
THROUGH THE NORTHERN WATERS TODAY RESULTING IN LIGHT SOUTHERLY
WINDS AND SCATTERED SHOWERS. THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS NORTH OF POINT REYES AND IN THE SAN FRANCISCO BAY
THIS AFTERNOON. WINDS WILL BECOME LIGHT TO MODERATE NORTHWEST
FRIDAY THROUGH SUNDAY AFTER THE LOW MOVES INLAND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: KBB
AVIATION/MARINE: CW
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
349 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF LIGHT
RAIN TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH AND IN
COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL AVERAGES
TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND SATURDAY. DRY
CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT PACIFIC WEATHER
SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD MIDWEEK.
&&
.DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 10:00 PM PDT WEDNESDAY...RAIN...MOSTLY LIGHT IN
INTENSITY AND ON THE IMMEDIATE COAST CONTINUES TO MOVE SOUTH THIS
EVENING. CIGS AT AREA TERMINALS WILL GRADUALLY LOWER TO MVFR
LEVELS OVERNIGHT.
VICINITY OF KSFO...LIGHT DRIZZLE REPORTED AT KSFO NOW. THE LOWER TO
MID LEVEL CLOUDS WILL MOVE IN LATER TONIGHT. MVFR CIGS WITH LIGHT
RAIN LATE TONIGHT. WET RUNWAYS.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR HOLDING TOGETHER SO FAR BUT POTENTIAL
IS THERE FOR LOW CLOUD DEVELOPMENT AHEAD OF THE INCOMING LOW.
CLOUD LAYERS TONIGHT FORECAST TO BE PRIMARILY MVFR.
&&
.MARINE...AS OF 6:35 PM PDT WEDNESDAY...VERY LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL IMPACT THE WATERS THROUGH THURSDAY. A LOW
IS CENTERED 350 MILES WEST OF UKIAH. THIS LOW WILL MOVE THROUGH
THE NORTHERN WATERS ON THURSDAY RESULTING IN LIGHT SOUTHERLY WINDS
WITH A CHANCE OF SHOWERS. THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS THIS EVENING NORTH OF POINT REYES AND IN THE SAN
FRANCISCO BAY THURSDAY. WINDS WILL BECOME LIGHT TO MODERATE
NORTHWEST FRIDAY THROUGH SUNDAY AFTER THE LOW MOVES INLAND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: KBB
AVIATION: CANEPA
MARINE: W PI/CANEPA
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
930 AM EDT THU SEP 18 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE THROUGH OUR AREA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL THEN BUILD IN TONIGHT INTO FRIDAY,
BEFORE SHIFTING OFFSHORE FRIDAY NIGHT. A WARM FRONT WILL LIFT TO
OUR NORTHWEST SATURDAY, THEN A COLD FRONT IS EXPECTED TO ARRIVE
LATE SUNDAY INTO MONDAY. THIS FRONT WILL SETTLE TO OUR SOUTH AND
EAST DURING MONDAY, THEN AN EXPANSIVE AREA OF HIGH PRESSURE IS
SCHEDULED TO BUILD IN FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE MID-ATLANTIC IS LOCATED TOWARD THE BASE OF AN UPPER TROUGH AS
SEEN ON WATER VAPOR SATELLITE IMAGERY THIS MORNING. THIS LARGE-SCALE
TROUGH IS ASSOCIATED WITH AN UPPER LOW LOCATED JUST TO THE EAST OF
HUDSON BAY. A COLD FRONT STRETCHING FROM THE GULF OF ST LAWRENCE
SOUTHEASTWARD INTO UPSTATE NY WAS RATHER DIFFUSE ON THE 13Z SFC
ANALYSIS. THE COLD FRONT WILL MOVE SOUTHWARD INTO THE MID-ATLANTIC
REGION THIS AFTERNOON.
12Z IAD, APG AND OKX SOUNDINGS ALL OBSERVED A SHALLOW SATURATED
LAYER BETWEEN 800-700 MB WITH MOISTURE TRAPPED BELOW THE MID-LEVEL
SUBSIDENCE INVERSION. MODEST LIFT ASSOCIATED WITH A SHORTWAVE TROUGH
HAS LEAD TO A BAND OF BKN-OVC STRATOCU OVER EASTERN PA, NORTHWEST NJ
AND THE EASTERN MD SO FAR THIS MORNING. TRIED TO TIME EASTWARD
PROGRESSION OF THE TROUGH AND ASSOCIATED STRATOCU IN HOURLY SKY
GRIDS WITH THE MORNING UPDATE. LATEST RAP MODEL, WHICH HAD
INITIALIZED WELL WITH CURRENT CLOUD COVER, HANGS ON TO THE MORNING
CLOUD THE LONGEST INTO THE AFTERNOON OVER SOUTHEASTERN PA AND THE
DELMARVA.
FORECAST MAX TEMPS TODAY IN THE MID 70S ARE ONLY A COUPLE OF DEGREES
BELOW CLIMO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE MID-LEVEL TROF AXIS MOVES OFF THE COAST THIS EVENING. A SURFACE
HIGH BEHIND THE COLD FRONT BEGINS TO BUILD IN ACROSS THE AREA.
TEMPERATURES WILL SETTLE IN THE LOWER 40S ACROSS THE SOUTHERN
POCONOS TO THE MID 50S ACROSS THE COASTAL PLAIN. THIS IS A FEW
DEGREES BELOW NORMAL.
COULD BE A BIT MORE CLOUDINESS ACROSS THE SOUTHERN ZONES, BUT NO
PRECIPITATION IS EXPECTED. SOME PATCHY FOG IS POSSIBLE TOWARD
MORNING.
NORTHWEST WINDS ON THE LIGHTER SIDE WILL SHIFT OUT OF THE NORTH OR
NORTHEAST BY THE FRIDAY SUNRISE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF THE FLOW BECOMING MORE
ZONAL FRIDAY ACROSS THE NORTHERN HALF OF THE NATION. SOME RIDGE
DEVELOPMENT THOUGH OUT WEST LOOKS TO ALLOW A SHORT WAVE TO DIVE INTO
THE MIDWEST SATURDAY, WHICH RESULTS IN A TROUGH AMPLIFYING ACROSS
THE GREAT LAKES AND NORTHEAST SUNDAY THROUGH MONDAY. THIS TROUGH MAY
THEN START TO LIFT OUT LATE TUESDAY. IT APPEARS THE MAIN FRONTAL
PASSAGE OCCURS SUNDAY NIGHT INTO MONDAY, THEN AN EXPANSIVE SURFACE
HIGH IS SCHEDULED TO BUILD ACROSS THE REGION TUESDAY AND WEDNESDAY.
WE USED A GENERAL MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN
BLENDED IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE
THEN MADE AFTER ADDITIONAL COLLABORATION WITH OUR SURROUNDING
OFFICES.
FOR FRIDAY...STRONG SURFACE HIGH PRESSURE SHOULD BE SHIFTING OFF THE
NEW ENGLAND COAST WITH OUR LOW-LEVEL FLOW TURNING EAST AND
SOUTHEAST. THERE IS SOME MOISTURE FORECAST TO BE LINGERING WELL
OFFSHORE ESPECIALLY TO OUR SOUTHEAST, AND THE ONSHORE FLOW INTO OUR
AREA MAY RESULT IN SOME CLOUDINESS ESPECIALLY AT NIGHT. THE
POTENTIAL COMPLICATION IS THAT THE LOW-LEVEL FLOW MAY ACTUALLY VEER
TO MORE SOUTHEAST OR SOUTH THROUGH FRIDAY NIGHT, FOCUSING AN
INCREASE IN MOISTURE NORTHWEST OF THE FALL LINE. IT IS HERE WHERE
PERHAPS SOME STRATUS AND/OR FOG DEVELOPS AS THE LOW-LEVEL MOISTURE
POOLS BENEATH AN INVERSION. AS OF NOW, NOT QUITE SURE HOW MUCH
STRATUS DEVELOPS DUE TO SOME QUESTION ON HOW QUICK THE LOWER LEVELS
MOISTEN UP. FOR NOW, WE INCREASED THE CLOUDS ESPECIALLY AT NIGHT A
BIT MORE. THE COMBINATION OF A NEW AIRMASS AND THE ONSHORE FLOW
SHOULD RESULT IN A COOL DAY ACROSS THE CWA, AND POTENTIALLY BREEZY
ALONG THE COAST.
FOR SATURDAY AND SUNDAY...HIGH PRESSURE BECOMES ELONGATED INTO THE
MID ATLANTIC AS IT WEAKENS AND SHIFTS FARTHER OFFSHORE. THIS OCCURS
AS SOME WAA GETS UNDERWAY AHEAD OF THE NEXT SYSTEM AND HEIGHTS RISE
SOME. THIS SHOULD RESULT IN A NORTHBOUND WARM FRONT THAT MOSTLY
SLIDES JUST TO OUR NORTHWEST, AND WARMER AIR ARRIVES ACROSS OUR CWA
ESPECIALLY SUNDAY WITH A MORE SOUTHWESTERLY LOW-LEVEL FLOW. A SHORT
WAVE DIVING ACROSS THE GREAT LAKES WILL DRIVE A SURFACE LOW
EASTWARD. THE AMPLIFICATION OF THE UPPER-LEVEL TROUGH SHOULD TAKE
THE MAIN SURFACE LOW WELL TO OUR NORTH THOUGH DURING SUNDAY. THE
ASSOCIATED COLD FRONT HOWEVER WILL ARRIVE INTO OUR AREA LATE SUNDAY
WITH SOME SHOWERS. A BAND OF SHOWERS MAY END UP WEAKENING WITH A
SOUTHEASTERN EXTENT DUE TO MUCH OF THE LARGE SCALE LIFT PEELING
AWAY TO THE NORTH. THE INSTABILITY LOOKS LOW THEREFORE WE
CONTINUED WITH NO THUNDER MENTION ATTM. WE GENERALLY FAVORED A
BLEND OF CONTINUITY AND WPC GUIDANCE, WHICH PAINTS SLIGHT CHC TO
LOW CHC POPS ACROSS THE CWA MAINLY SUNDAY NIGHT. MEANWHILE, A LEAD
SHORT WAVE NEAR THE CAROLINAS MAY ORGANIZE A SURFACE LOW ALONG AN
OLD BAROCLINIC ZONE. THIS FEATURE SHOULD TRACK NORTHEAST AND HAVE
NO REAL AFFECT ON OUR SENSIBLE WEATHER.
FOR MONDAY AND TUESDAY...THE MAIN UPPER-LEVEL TROUGH MAY AMPLIFY
SOME MORE ACROSS THE NORTHEAST AND MID ATLANTIC REGIONS MONDAY.
BASED ON SOME RIDGING ENTERING THE PLAINS, AN EXPANSIVE SURFACE HIGH
IS FORECAST TO BUILD ACROSS THE MIDWEST AND GREAT LAKES LATER MONDAY
INTO TUESDAY, WITH THIS FEATURE ARRIVING INTO OUR AREA DURING
TUESDAY. SOME GUIDANCE SHOWS SOME INSTABILITY TYPE SHOWERS OCCURRING
JUST TO OUR NORTH TUESDAY AS ANOTHER SHORT WAVE ROTATES AROUND THE
BASE OF THE UPPER-LEVEL TROUGH. REGARDING POPS, KEPT SOME SLIGHT CHC
TO LOW CHC POPS ESPECIALLY MONDAY MORNING WITH THE DEPARTING COLD
FRONT. WE CARRIED A DRY FORECAST FOR TUESDAY AS THE UPPER-LEVEL
TROUGH MAY START TO LIFT OUT SOME WITH ANY FOCUS GENERALLY TO OUR
NORTH.
FOR WEDNESDAY...AS A RIDGE SLIDES ACROSS THE GREAT LAKES, A
POTENTIALLY STRONG SURFACE HIGH BUILDS ACROSS THE NORTHEAST AND MID
ATLANTIC REGIONS. IF THE CENTER OF THIS HIGH ENDS UP ACROSS NEW
ENGLAND, THEN WE WILL HAVE AN ONSHORE FLOW ONCE AGAIN. AS OF NOW,
LEANED MUCH CLOSER TO THE 00Z WPC GUIDANCE FOR ALL WEATHER ELEMENTS.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS
VFR TDA AND TNGT. STRATOCU BETWEEN 5-9 KFT PROGRESSES EASTWARD
ACROSS THE TERMINALS TDA. NW WINDS UNDER 10 KT TODAY WILL VEER TO
THE N THIS EVE AND NE BY EARLY FRI MRNG.
OUTLOOK...
FRIDAY...VFR THROUGH THE DAY, HOWEVER SOME LOW CLOUDS OR EVEN SOME
FOG COULD DEVELOP OVERNIGHT WITHIN AN ONSHORE FLOW. OUR CONFIDENCE
IS ON THE LOWER SIDE.
SATURDAY AND SUNDAY...SOME LOW CLOUDS AND/OR SOME FOG TO START EACH
DAY, OTHERWISE MOSTLY VFR. A COLD FRONT ARRIVES SUNDAY NIGHT WITH
POSSIBLE SHOWERS AND LOCAL SUB-VFR CONDITIONS.
MONDAY...SOME SHOWERS POSSIBLE ESPECIALLY IN THE MORNING, OTHERWISE
MOSTLY VFR WITH A WIND SHIFT TO THE NORTHWEST.
&&
.MARINE...
BUOY 44065 CAME BACK ON LINE ABOUT 10 PM LAST NIGHT. HOPEFULLY BUOY
44025 WILL NOT BE FAR BEHIND.
TODAY...LONG PERIOD SWELLS GENERATED BY EDOUARD CONTINUE TO REACH
THE EAST COAST TODAY. LATEST OBS SHOW 13-14 SEC WAVE PERIODS THIS
MORNING. SEAS EXPECTED TO REMAIN JUST BELOW SCA LEVELS WIT WAVE
HEIGHTS ARE 4 FT WHILE NORTHERLY WINDS WILL BE AROUND 10 KT
(GUSTING TO 20 KT LATE IN THE DAY).
TONIGHT...SWELLS ARE STILL FORECAST TO BE WITH US THROUGH TONIGHT.
SEAS WILL BE LESS THAN 4 FEET. LIGHT NORTHERLY WINDS WILL INCREASE
TO 20 KT OVERNIGHT ESPECIALLY ACROSS THE NORTHERN WATERS.
OUTLOOK...
FRIDAY...A NORTHEASTERLY WIND SURGE WITH AN INITIAL TIGHTENING OF
THE PRESSURE GRADIENT AND CAA SHOULD THEN EASE SOME AS THE WINDS
TURN EAST-SOUTHEAST BY LATE IN THE DAY AND AT NIGHT. THE SURGE COULD
BE ENOUGH FOR SOME 25-KNOT GUSTS AND SEAS BUILDING TO 5 FEET ON THE
COASTAL WATERS FOR A TIME. AS OF NOW THE WINDS AND SEAS ARE
MARGINAL AND THEREFORE WILL HOLD OFF ON AN ADVISORY.
SATURDAY AND SUNDAY...THE WINDS SHOULD TURN FROM THE SOUTH DURING
THIS TIME FRAME AS HIGH PRESSURE DEPARTS TO THE EAST. THE NEXT COLD
FRONT ARRIVES SUNDAY NIGHT, HOWEVER AN INCREASE IN THE WINDS SHOULD
OCCUR AHEAD OF IT BUT THEY SHOULD BE BELOW ADVISORY CRITERIA. THE
SEAS HOWEVER COULD BE RIGHT NEAR 5 FEET SATURDAY FROM THE EARLIER
ONSHORE COMPONENT.
MONDAY...THE CONDITIONS SHOULD BE BELOW ADVISORY CRITERIA OVERALL AS
WINDS SHIFT FROM THE NORTH AS HIGH PRESSURE STARTS TO BUILD IN LATE.
&&
.RIP CURRENTS...
IN HOUSE GUIDANCE SUGGESTS A MODERATE RISK TODAY FOR NJ/DE BECAUSE OF
LONG PERIOD SWELLS GENERATED BY EDOUARD.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...KLEIN
SHORT TERM...KRUZDLO
LONG TERM...GORSE
AVIATION...GORSE/KLEIN
MARINE...GORSE/KLEIN/KRUZDLO
RIP CURRENTS...KRUZDLO/KLEIN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
11 AM EDT THU SEP 18 2014
.DISCUSSION...
PATCHY LOW CLOUDS LINGERING FROM VERO BEACH AND FORT PIERCE WEST TO
THE KISSIMMEE RIVER WILL LIFT BY NOON. MORNING CAPE SOUNDING SHOWS
MUCH DRIER AIR ABOVE 850 MB BUT SUFFICIENT LOW LEVEL MOISTURE
REMAINS SO EXPECT SCATTERED CU TO DEVELOP. HAVE ADJUSTED POPS JUST A
LITTLE...REDUCING RAIN CHANCES ALONG THE TREASURE COAST TO 20
PERCENT IN ORDER TO SHOW THAT THE BEST CHANCE FOR SHOWERS THIS AFTN
WILL BE OVER THE INTERIOR AND AROUND LAKE OKEECHOBEE. LIGHT N/NW
WINDS THIS MORNING WILL TURN NE TO EAST THIS AFTERNOON. OUR LOCAL
WRF AND THE HRRR MODEL ARE IN GOOD AGREEMENT REGARDING EXPECTED
EVOLUTION OF CONVECTION THIS AFTERNOON SHOWING THE BEST CHANCE FOR
SHOWERS AND A FEW STORMS AROUND LAKE OKEECHOBEE AS WELL AS THE NORTH
INTERIOR. MOTION GENERALLY TOWARD THE S/SW.
PREVIOUS DAY 1 DISCUSSION...
LITTLE IN THE WAY OF ORGANIZED PRECIP TODAY AS THE RELATIVELY STABLE
AIRMASS OVERHEAD LIMITS VERTICAL MOTION...WHILE DRY AIR ALOFT LIMITS
POTENTIAL FOR CU DVLPMNT. BROAD LOW PRES OVER THE W ATLC WILL LIFT
NE...ALLOWING HI PRES TO BUILD DOWN THE ERN SEABOARD IN ITS WAKE. AS
IT DOES...LIGHT NWRLY WINDS THRU THE H100-H85 LYR WILL VEER TO THE
NE BY MIDDAY...THEN TO THE E THRU SUNSET.
NW/NE FLOW REGIMES TYPICALLY DO NOT PRODUCE MUCH IN THE WAY OF
THUNDER OVER CENTRAL FL. CANNOT COMPLETELY RULE OUT PRECIP WITH SFC
DEWPOINTS IN THE L70S AND H100-H70 MEAN RH VALUES RUINING BTWN
70-80PCT. HOWEVER...THE DLVPG ONSHORE FLOW WILL LIMIT THE WINDOW OF
OPPORTUNITY FOR COASTAL TSRA DVLPMNT. INTERIOR WILL HAVE A BETTER
OPPORTUNITY AS NEAR FULL SUN WILL ALLOW TEMPS TO REACH THEIR
CONVECTIVE TRIGGERS BY EARLY AFTN. HOWEVER...WITH PWAT VALUES
EXPECTED TO DROP TO ARND 1.6"...CHANCES WILL BE AOB 20PCT OVER MOST
OF THE AREA....WITH GO WITH 30 POPS ARND LAKE OKEECHOBEE DUE TO
SLIGHTLY HIGHER MOISTURE PROFILE. PRECIP SHOULD BURN OUT BY SUNSET
OR SHORTLY THEREAFTER.
DVLPG ONSHORE FLOW WILL KEEP MAX TEMPS ALONG THE COAST IN THE
M/U80S...INTERIOR WARMING INTO THE L90S. MIN TEMPS HOLDING IN THE
L/M70S AREAWIDE OVERNIGHT AS THE CONTINUING ONSHORE FLOW WILL
QUICKLY MODIFY WHATEVER LOW DEWPOINT AIR THAT MANAGES TO FILTER INTO
THE CWA.
&&
.AVIATION...
LINGERING MVFR CIGS AT VRB/FPR WILL LIFT BY 16Z. BRIEF MVFR CIGS
WILL BE POSSIBLE ELSEWHERE AS SFC HEATING WORKS ON LOW LEVEL
MOISTURE BUT ENTRAINMENT OF DRIER AIR ALOFT SHOULD LIMIT DURATION OF
MVFR CONDS. ISOLATED SHRA/TSRA AFT 17Z PUSHING SOUTHWARD MAY IMPACT
SFB/MCO/LEE. LIGHT N/NW FLOW TURNING NE TO EAST.
&&
.MARINE...
NO SIGNIFICANT CHANGES TO CURRENT COASTAL WATERS FORECAST.
WEAK HI PRES OVER NEW ENGLAND AND THE MID ATLC STATES WILL NUDGE ITS
WAY OFF THE ERN SEABOARD... ALLOWING SFC/BNDRY LYR WINDS OVER THE
LCL ATLC TO VEER TO THE N/NE BY MIDDAY...THEN TO THE E BY LATE
AFTN...STEADY SPEEDS BTWN 8-10KTS. LONG PD SWELLS FROM HURRICANE
EDOUARD WILL DAMPEN OVER THE LCL ATLC THRU THE DAY...SUBSIDING TO
2-3FT NEARSHORE AND 3-4FT OFFSHORE TODAY...THEN 2-3FT AREAWIDE
TONIGHT. ISOLD SHRAS LIMITED TO THE GULF STREAM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 87 74 83 71 / 20 10 60 40
MCO 91 73 87 69 / 20 20 60 50
MLB 87 75 84 73 / 20 10 70 50
VRB 86 73 85 73 / 20 10 70 50
LEE 91 74 88 68 / 20 20 60 40
SFB 91 74 86 70 / 20 20 60 40
ORL 91 74 86 69 / 20 20 60 50
FPR 87 73 86 73 / 30 10 70 50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
KELLY/VOLKMER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1040 AM CDT THU SEP 18 2014
.UPDATE...
WV/IR SATELLITE SHOW INCREASED STRATOCU PUSHING INTO THE AREA. THE
LATEST SHORT TERM GUIDANCE APPEARS TO HAVE A GOOD GRASP OF THE
CURRENT CONDITIONS WITH THE STATIONARY FRONT LOCATED FROM CENTRAL
TEXAS THROUGH NORTHERN LOUISIANA AND A FAIRLY STRONG UPPER LEVEL
DISTURBANCE JUST OFFSHORE. THIS IS FORCING A BROAD AREA OF MOSTLY
STRATOFORM SHOWERS OVER PARTS OF SETX NEAR THE HOUSTON AREA RIGHT
NOW. UPPER LEVEL WINDS ARE RELATIVELY WEAK AND THUS THE STORM
MOTION OF THAT SYSTEM IS EXPECTED TO BE SLOW. LATEST HRRR GUIDANCE
SUGGESTS THAT THE TIMING OF THE ONSET OF THE HEAVIEST SHOWERS
SHOULD BE AROUND 17Z AND NOT PROJECTED TO MOVE VERY QUICKLY ACROSS
SETX. TIMING OF THE SHOWERS MOVING OUT OF THE AREA IS SOMEWHERE
BETWEEN 22Z TO 01Z THIS EVENING. STORM TOTAL QPF OVER SETX IS
STILL IN THE BALL PARK OF 1 TO 2 INCHES SO I CHOOSE TO NOT INCLUDE
A FLASH FLOOD WATCH ALTHOUGH SOME URBAN FLOODING COULD BE
POSSIBLE.
DEAL
&&
.PREV DISCUSSION... /ISSUED 631 AM CDT THU SEP 18 2014/
AVIATION...
A STATIONARY FRONT DRAPES THROUGH DALLAS THROUGH LAFAYETTE THIS
MORNING...SLOPING TOWARD THE GULF AIR WITH HEIGHT. THE FRONTAL
SURFACE SEPARATES MOIST UNSTABLE AIR SOUTH AND WEST...FROM DRIER
STABLE AIR NORTH AND EAST.
NORTHWESTERLY SHORTWAVES ALOFT WILL TRAVEL OVER THE FRONTAL ZONE
..SETTING OFF SCATTERED SHOWERS AND THUNDERSTORMS. THE HEAVIEST
ACTIVITY WILL BE ALONG THE BEAUMONT TO LAKE CHARLES AIR CORRIDOR.
JT
PREV DISCUSSION... /ISSUED 349 AM CDT THU SEP 18 2014/
DISCUSSION...LOCAL RADAR DEPICTING JUST A BIT OF LIGHT RAIN OR
DRIZZLE OVER EAST TEXAS JUST CLIPPING OUR WESTERN MOST COUNTIES.
STRATOFORM PRECIP EXTENTS EAST FROM MORE ROBUST CONVECTION OVER
SOUTH CENTRAL TEXAS WHICH IS ADVANCING SOUTHEAST. SURFACE OBS OVER
THE FORECAST AREA SHOWING LITTLE IN THE WAY OF FOG...AND WITH
EXTENSIVE CLOUDINESS INCOMING EXPECT THAT TO REMAIN THE CASE.
TODAY...NORTHWEST TO SOUTHEAST MOISTURE AXIS SET UP OVER THE
SOUTHERN PORTION OF THE FORECAST AREA WILL CONTINUE TO BE THE
FOCUS FOR SHOWERS AND THUNDERSTORMS. PRECIPITABLE WATER PROGGED
AS HIGH AS 2.5 INCHES AT BPT AT 18Z...BUT TRENDING TOWARD THE NORM
AT AEX COMING IN AT 1.8 INCHES. WITH THAT SAID...POPS WILL
CONTINUE TO BE ALIGNED ACCORDINGLY FROM CATEGORICAL FOR THE
SOUTHWEST PORTION OF THE FORECAST AREA...TO JUST A CHANCE ADVANCING
INTO CENTRAL LOUISIANA. INCREASED ACTIVITY EXPECTED TODAY WITH THE
APPROACH AND PASSAGE OF A VIGOROUS SHORTWAVE TROF. GUIDANCE
SUGGESTING HEAVIEST RAINS OVER LOWER SOUTHEAST TEXAS INCLUDING THE
BEAUMONT AREA. QPF SHOWING 1 TO 2 INCHES.
WITH EASTWARD ADVANCEMENT OF SHORTWAVE AND AMPLIFICATION OF MID-CONUS
TROF...THE AREA WILL COME UNDER A DEEP NORTHERLY FLOW. THIS WILL
SHUNT THE DEEP MOISTURE INTO THE GULF WATERS RESULTING IN DECREASING
RAIN CHANCES OVER THE AREA MOVING THROUGH FRIDAY. WITH EXTENT OF
DRIER AIR INCOMING...HAVE OPTED TO REMOVE ANY RAIN CHANCE FOR SATURDAY.
THE NEW WEEK...COLD FRONT EXPECTED TO MOVE ACROSS THROUGH MONDAY.
MOISTURE WILL BE SOMEWHAT LIMITED AND SIMPLY CARRYING LOW END POPS
AT THIS TIME. SUFFICIENT MOISTURE REMAINS IN PLACE AFTER FROPA TO
MAINTAIN A CONTINUED CHANCE FOR A FEW SHOWERS. OTHERWISE LOOKING
FOR SLIGHTLY COOLER TEMPS AND LOWER HUMIDITY FOR THE WEEK.
MARINE...WIDESPREAD SHOWERS AND THUNDERSTORMS CAN BE EXPECTED
OVER THE NORTHWEST GULF TODAY. THIS AS DEEP TROPICAL MOISTURE
REMAINS IN PLACE...IN CONCERT WITH A VIGOROUS UPPER LEVEL
DISTURBANCE ADVANCING THROUGH. RAIN CHANCES WILL DIMINISH FOR
FRIDAY AND THE WEEKEND AS THE DEEP MOISTURE IS DISPLACE SOUTHWARD
WITH PASSAGE OF THE DISTURBANCE AND AMPLIFICATION OF A MID-CONUS
RIDGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 83 72 86 71 89 / 80 60 30 10 10
KBPT 82 72 85 73 88 / 80 60 50 10 10
KAEX 85 69 87 69 91 / 50 30 20 10 10
KLFT 85 72 86 71 89 / 60 40 20 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSLAKECHARLES
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WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
733 AM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 459 AM EDT THU SEP 18 2014
MAIN FCST CONCERN FOCUSES ON CHCS FOR SHRA FRI THRU SUN AS A SERIES
OF SHRTWVS IN A W-NW FLOW MOVE ACROSS THE UPPER GREAT LAKES REGION.
MODELS COMING INTO BETTER AGREEMENT SHOWING THE FIRST IN A SERIES OF
SHORTWAVES MOVING INTO THE NRN PLAINS ON FRI. STRENGTHENING WAA AND
INCREASINGLY MOIST SW FLOW AHEAD OF THIS SHORTWAVE AND ITS ASSOC
TROUGH/FRONTAL BOUNDARY OVER THE NRN PLAINS WILL INCREASE PWAT
VALUES TO 1.5 INCHES OR HIGHER (MORE THAN 180 PCT OF NORMAL) OVER
THE FCST AREA BY FRI AFTERNOON. MODEL SNDGS INDICATE 500-1000 J/KG
OF MUCAPE AND SHOWALTER INDICES DROPPING AS LOW AS -2 TO -4C BY FRI
AFTERNOON/FRI NIGHT SO WOULD EXPECT AN INCREASING POTENTIAL FOR
ELEVATED TSRA AS THE WARM FRONT APPROACHES LATE IN THE DAY. MODEL
CONSENSUS SUGGESTS THE BEST CHC FOR SHOWERS WL BE OVER THE W HALF
OF THE CWA FRI AFTERNOON AND OVER THE E HALF FRI EVNG...WHEN
ISENTROPIC ASCENT/H925-7 MSTR TRANSPORT AND DEEP LAYER Q-VECT CONV
WL BE MAXIMIZED OVER THOSE AREAS. AS FOR TEMPS...INCREASING CLD COVER
WL HOLD DOWN SFC HI TEMPS INTO THE 60S ON FRI DESPITE INFLUX OF MUCH
WARMER AIR. EXPECT RELATIVELY SMALL TEMP FALL ON FRI NGT WITH STRONG
SW FLOW AND INFLUX OF HIGHER PWAT.
SAT...ANOTHER STRONGER SHRTWV APPROACHING FROM SCNTRL CANADA AND THE
NRN PLAINS WILL PROPEL THE SFC LOW PRES TROUGH AND ASSOC COLD FNT
THRU THE UPR LAKES. THERE MAY BE A BETTER CHANCE OF SHOWERS/TS
AGAIN SAT AFTERNOON MAINLY OVER CENTRAL AND ERN COUNTIES AS DYNAMICS
WITH SHORTWAVE LOOK TO BE IN SYNC WITH DAYTIME HEATING AND TIMING OF
COLD FRONTAL PASSAGE. MLCAPES FCST IN EXCESS OF 1000 J/KG WOULD
SUPPORT THUNDER AND WITH DEEP LAYER SHEAR VALUES OF 45-50 KTS A FEW
STRONG TO POSSIBLY SVR STORMS WOULD NOT BE OUT OF THE QUESTION IF
INSTABILITY IS REALIZED. WILL MENTION THIS POTENTIAL IN HWO.
DEPENDING ON HOW QUICKLY THE SFC COLD FNT PASSES ON SAT AND
POTENTIAL BREAKS IN CLOUD COVER...SOME PLACES MAINLY OVER THE CNTRL
CWA COULD SEE TEMPS RISE WELL INTO THE 70S AS H85 TEMPS ARE FCST TO
PEAK AS HI AS 16-17C.
SAT NGT INTO SUN...ALTHOUGH MODELS SHOW TIMING DIFFERENCES...THEY
SEEM TO BE IN AGREEMENT THAT ADDITIONAL SHRTWVS WILL BE DROPPING
INTO THE GREAT LKS THAT ARE FCST TO DEEPEN AN UPR TROF OVER THE
REGION. THE RESULTING NW CYCLONIC FLOW OVER THE AREA ALONG WITH THE
PASSAGE OF A SECONDARY COLD FRONT SHOULD YIELD A GOOD DEAL OF CLD
COVER...PERIODS OF SHOWERS AND COOLER WX AS H85 TEMPS DROP FM AS HI
AS 15C ON SAT AFTN TO AS LO AS 2-4C BY LATE SUN. IT APPEARS
UNLIKELY THAT H85 TEMPS WL FALL ENOUGH TO REALIZE MUCH OF A LK
ENHANCED COMPONENT TO THE CLDS/SHOWERS SUN AND SUN NGT WITH WSHFT TO
THE N GIVEN FAIRLY CHILLY LAKE SUPERIOR TEMPS OF 8-9C.
EXTENDED...WITH HI PRES AND MUCH DRIER AIR MOVING INTO THE GREAT LKS
EARLY NEXT WEEK...EXPECT DRY WX TO PREVAIL FROM MON THRU WED. MON IS
LIKELY TO BE RATHER COOL...BUT RETURN SW FLOW ON THE NW FLANK OF THE
HI SHIFTING TOWARD THE LOWER LKS WL BRING A WARMING TREND TUE THRU
WED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 731 AM EDT THU SEP 18 2014
EXPECT MVFR LOW CLOUDS TO PERSIST UNTIL MID MORNING AT SAW WHEN WIND
EASTERLY WINDS OFF OF THE LAND BRING CLEARING. VFR CONDITIONS WILL
THEN BE THE RULE AT KSAW TODAY UNDER A DRY AIR MASS. AT KCMX...THE
MVFR CIG MAY LAST TOWARD NOON GIVEN THE AMOUNT OF UPSTREAM CLOUDS AND
UPSLOPE ESE FLOW OFF OF LAKE SUPERIOR. AT IWD...MVFR CIGS WILL GIVE
WAY TO CLEARING AS VEERING WINDS TO SE RESULT IN A DOWNSLOPE FLOW AND
DAYTIME HEATING/MIXING STRENGTHEN. VFR CONDITIONS WILL THEN PREVAIL
FOR THE REMAINDER OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
700 AM CDT THU SEP 18 2014
.SYNOPSIS...
ISSUED AT 355 AM CDT THU SEP 18 2014
SURFACE LOW PRESSURE EXTENDS SOUTH FROM ALBERTA CANADA INTO
NEVADA AND WESTERN ARIZONA. SURFACE HIGH PRESSURE CENTER LOCATED
OVER THE NORTHERN GREAT LAKES. STRATUS IS DEVELOPING AND
EXPANDING FROM NWRN KS INTO SWRN NEBR AND THE SOUTHERN NEBRASKA
PANHANDLE EARLY THIS MORNING. PORTIONS OF CENTRAL AND SOUTHWEST
NEBRASKA REPORTING MAINLY LIGHT FOG 3-5SM WITH LOCALLY DENSE FOG
AT THE KBBW ASOS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU SEP 18 2014
NEAR TERM CONCERN IS DEVELOPMENT OF STRATUS AND FOG DEVELOPMENT
ACROSS PORTIONS OF CENTRAL AND SOUTHWEST NEBRASKA. WHILE LOW
VISIBILITY OF 1/4-1/2SM AT KBBW IS POSSIBLE ACROSS THE
AREA...PREVAILING VISIBILITIES SHOULD RANGE FROM 3-5 SM OR
HIGHER. AREAS TO PATCHY FOG IN THE FORECAST UNTIL 15Z.
OTHERWISE...STRATUS IS FORECAST TO QUICKLY EXPAND NORTHWESTWARD
INTO WESTERN NEBRASKA THIS MORNING. MODELS SHOW A NEARLY
SATURATED H9-H85 LAYER PRESENT WITH RELATIVELY DRY AIR ALOFT. THE
STRATUS IS FORECAST TO EXIT MUCH OF THE PANHANDLE BY 18Z...WHILE
POTENTIALLY PERSISTING OVER PORTIONS OF SWRN INTO CENTRAL
NEBRASKA THROUGH THE AFTERNOON. THIS AGREED UPON BY THE NAM AND
06Z RAP MODEL. THE GFS IS LESS AGGRESSIVE WITH CLOUDS WITH MUCH
HIGHER MOS GUIDANCE. USING 00Z SUPERBLEND OUTPUT...BLENDED WITH
THE 00Z MET GUIDANCE TO REFLECT COOLER HIGHS. WHERE CLEARING
OCCURS ACROSS WRN TIER OF COUNTIES...HIGHS IN THE UPPER 80S
ATTAINABLE. MID 70S FORECAST FOR PORTIONS OF CENTRAL AND SERN
ZONES. ALSO INCREASED PERCENT SKY COVER TO REFLECT MOSTLY CLOUDY
SKIES CENTRAL AND SERN ZONES.
STRONG WARM AIR ADVECTION TONIGHT WITH H85 TEMPS UP TO 25C. THIS
WILL CAUSE LINGERING STRATUS THIS EVENING TO QUICKLY LIFT
NORTHEAST AND DISPERSE AFTER 06Z. LOWS TONIGHT WILL BE MILDER
THAN THE PAST SEVERAL NIGHTS RANGING MAINLY IN THE LOWER 60S.
THERE WILL BE A STRONG INVERSION WITH SOUTH WINDS BECOMING
SOUTHWEST LATE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU SEP 18 2014
FRIDAY WILL BE AN UNSEASONABLE WARM DAY AS A LOW DEVELOPS OVER SW
S DAKOTA ALONG A COLD FRONT STRETCHED FROM THE NORTHERN PLAINS
INTO WYOMING. SOUTHERLY WINDS INCREASE AHEAD OF THE FRONT WHICH
SHOULD MIX OUT ANY BL MOISTURE FOG/STRATUS. 850 MB TEMPS INTO THE
20S C AND MOS GUIDANCE WELL INTO THE 80S AND EVEN SOME LOW 90S.
SHOULD SEE SOME A FEW HIGH CLOUDS FROM STORM SYSTEM TO THE SOUTH
SO KEEP HIGHS CONSERVATIVE. COLD FRONT WILL WILL PUSH ACROSS THE
AREA FRIDAY NIGHT INTO SATURDAY. SOME ELEVATED INSTABILITY
OVERNIGHT...WITH AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY. THE ADDED CLOUDS SHOULD KEEP TEMPS
MILD OVERNIGHT.
COOLER BEHIND THE FRONT WITH PRECIP EXPECTED TO BE PUSHING EAST
IN THE MORNING. SOME SUN BEHIND THE FRONT AND TEMPS REBOUND TO
AROUND 80 ON SATURDAY.
COOL HIGH PRESSURE BUILDS IN OVER THE REST OF THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPS TO SLOWLY TREND DOWN THROUGH MONDAY.
MEANWHILE A DISTURBANCE WILL RIDE ALONG THE FRONT RANGE...HOWEVER
MODELS GENERALLY KEEP PRECIP WEST OF THE CWA.
NEXT WEEK THE HIGH SLIDES EAST WITH RETURN SOUTHERLY FLOW TO
BRING A RETURN OF MORE MOISTURE. A DISTURBANCE SHOULD RIDE ACROSS
THE CENTRAL ROCKIES EARLY MONDAY WITH A CHANCE FOR PRECIP LIFTING
ACROSS THE CWA MONDAY INTO TUESDAY. ALTHOUGH 850 TEMPS ON THE
RISE...CLOUDS /ASSOCIATED WITH THE DISTURBANCE/ LIKELY TO KEEP
TEMPS FROM JUMPING UP TO MUCH. GUIDANCE SUGGEST SEASONAL MID
70S...WHICH SEEMS REASONABLE AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 700 AM CDT THU SEP 18 2014
VLIFR CONDITIONS AT KLBF SHOULD IMPROVE TO IFR AFTER 15Z. STRTUS
AND FOG HAS ALSO MOVED INTO KVTN PRIOR TO 12Z WITH IFR CONDITIONS
EXPECTED TO BECOME VFR BY 18Z. A RETURN TO IFR IS POSSIBLE BY 03Z
19TH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
947 AM CDT THU SEP 18 2014
.UPDATE...
ISSUED AT 936 AM CDT THU SEP 18 2014
CHALLENGES FOR THIS MORNINGS UPDATE INCLUDES LOW STRATUS AND
DISSIPATING FOG. STRATUS DECK ALONG AND EAST OF THE RRV WILL
ERODE AS PRESSURE GRADIENT INCREASES BETWEEN DEPARTING GREAT
LAKES SFC HIGH AND DEVELOPING TROUGH OF LOW PRESSURE IN THE HIGH
PLAINS. THIS MIXING WILL QUICKLY ERODE THE STRATUS IN THE NEXT
COUPLE OF HOURS. THE RAP AND HRRR INDICATE THIS IN THEIR LATEST
SOLNS. ADJUSTED THE SKY GRIDS AND TEMP CURVE THROUGH EARLY
AFTERNOON AND KEPT THE INHERITED MAX TEMPS THE SAME.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
THE MAIN CHALLENGE WILL BE CONVECTIVE CHANCES LATER TODAY THROUGH
SATURDAY. MODELS REMAIN IN VERY GOOD OVERALL AGREEMENT...WITH A
FEW MINOR DIFFERENCES.
FOR TODAY...THERE WILL BE A BAND OF CLOUDS AT LEAST THIS MORNING
AFFECTING AREAS ALONG AND EAST OF THE VALLEY. THERE IS ALSO SOME
PATCHY FOG WITH THIS STRATUS...AND WILL ADD SOME FOR EARLY
MORNING. THIS STRATUS COULD HOLD TEMPS DOWN ONCE AGAIN IF THEY DO NOT
ERODE UNTIL MID/LATE AFTERNOON...SO TEMP FORECAST WILL BE TRICKY
FOR SOME AREAS WHERE CLOUDS HOLD. IT SHOULD REMAIN DRY THROUGH 00Z
FRI...WITH SOUTHEAST WINDS INCREASING THIS AFTERNOON.
FOR TONIGHT...THE CHANCES FOR SHOWERS AND STORMS SHOULD DEVELOP
FROM WEST TO EAST THROUGH THE NIGHT. IT COULD BE WINDY FOR MUCH OF
THE NIGHT WITH GOOD MIXING AT LEAST THIS EVENING...AND 30-40KT TO
MIX. A DEVELOPING INVERSION SHOULD KEEP STRONGER WINDS FROM MIXING
DOWN THOUGH. A STRONG CAP WILL BE IN PLACE MUCH OF THE NIGHT...BUT
THE CAP NEAR 850MB SHOULD ERODE LATE WITH THE BEST FORCING AND MID
LEVEL MOISTURE ADVECTION IN THE NORTH.
ON FRIDAY...THERE COULD BE A FEW BANDS OF SHOWERS AND STORMS...ONE
IN THE MORNING IN THE EAST...AND ANOTHER LATER IN THE AFTERNOON IN
THE WEST. GIVEN THESE TOUGH TO TIME WAVES...WE WILL CONTINUE WITH
MAINLY LOW END CHANCE POPS FOR SHOWERS AND STORMS. IT SHOULD BE
WARM WITH WESTERLY SFC WINDS AND AT LEAST SOME SUNSHINE...WITH
AROUND 80 IN THE WEST AND LOW 70S EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
FOR FRI NIGHT...EXPECT CONTINUED CHANCES FOR SOME CONVECTION...AS
AS A SFC BOUNDARY MOVES THROUGH THE AREA. THE BEST CHANCE FOR
MEASURABLE RAIN WILL OCCUR IN THE NORTHERN AREAS CLOSER TO SFC LOW TRACK.
ON SATURDAY...A STRONG SPEED MAX WILL ENHANCE LARGE SCALE
DIVERGENCE ALOFT. THIS COUPLED WITH PWATS STILL NEAR 1 INCH IN THE
NORTH...AND SOME LINGERING INSTABILITY SHOULD MEAN MAINLY SHOWER
CHANCES AND PERHAPS A RUMBLE OF THUNDER. THE BEST CHANCE FOR
PRECIP COULD OCCUR LATE IN THE MORNING/EARLY AFTERNOON AS
SHORTWAVE MOVES THROUGH. COOL ADVECTION WILL MOVE IN SAT AFTERNOON
WITH NW WINDS INCREASING TO AT LEAST 20KT IN THE NW...ALONG WITH
ADIABATIC SOUNDINGS UP TO AROUND 700MB WITH 35KT TO MIX. TEMPS
WILL BE COOL TO AROUND NORMAL...WITH MORE CLOUDS AND CAA BY
AFTERNOON.
FOR SAT NIGHT...IT SHOULD BE MAINLY DRY WITH PERHAPS A LINGERING
SHOWER MAINLY IN THE NORTHEAST.
LONG WAVE RIDGE AXIS REMAINS OVER WESTERN CANADA THROUGH MUCH OF THE
PERIOD. BY DAY 7 ZONAL FLOW IS ACROSS CANADA. THE GFS IS FASTER THAN
THE ECMWF. WILL PREFER THE SLOWER ECMWF.
UPPER LOW OFF THE WEST COAST IS FORECAST TO MOVE INTO THE PLAINS BY
WED. WILL ADD POPS FOR WED.
TEMPS WERE DECREASED BY A DEGREE FOR SUN AND INCREASED A DEGREE FOR
MON...TUE AND WED COMPARED TO YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 615 AM CDT THU SEP 18 2014
THE BAND OF IFR/LIFR STRATUS AND FOG CONTINUES TO ADVECT WEST INTO
THE VALLEY. THIS WILL BE CHALLENGING TO WHEN IT DISSIPATES...AND
IF KDVL IS AFFECTED. CURRENT THINKING IS IT WILL SLOW ITS WESTWARD
PROGRESSION WITHIN A FEW HOURS THEN DISSIPATE BY 18Z. THIS WILL
NEED TO BE MONITORED CLOSELY THOUGH. SOUTHEAST WINDS WILL INCREASE
THIS AFTERNOON AND COULD GUST TO AROUND 25KT LATE THIS AFTERNOON
INTO THIS EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JK
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...DK
AREA FORECAST DISCUSSION
NWS PENDLETON OR
859 AM PDT THU SEP 18 2014
.UPDATE...THE CURRENT FORECAST REMAINS ON TRACK WITH JUST A FEW
MINOR ADJUSTMENTS TO THE TODAY AND THIS EVENING PERIOD. HAVE MADE
SOME MINOR ADJUSTMENTS TO THE HIGHS TODAY...MAINLY ACROSS THE
WESTERN PORTION OF THE CWA.
EXPECT WINDY CONDITIONS ALONG THE KITTITAS VALLEY AND THE COLUMBIA
RIVER GORGE TODAY...WITH THE BASIN AND FOOTHILL AREAS BEING BREEZY.
EXPECT 20 MPH GUSTING TO 30 MPH FOR THE GORGE AND THE KITTIAS
VALLEY...WITH 15 MPH GUSTING 25 MPH ELSEWHERE ACROSS THE BASIN.
WINDS SHOULD BEGIN TO PICK UP AFTER NOON TODAY...AND ARE EXPECTED TO
BE STRONGEST AROUND 5 PM DIMINISHING AFTER MIDNIGHT.
HAVE ALSO PULLED BACK ON POPS TO GO MOSTLY SLIGHT CHANCE EAST OF THE
CASCADE CREST. THE SPLIT FLOW WILL CUT OFF MOST OF THE MOISTURE
FROM THE TROUGH THAT WILL PROGRESS SOUTH ALONG THE CALIFORNIA COAST
TODAY INTO TONIGHT. SLIGHT CHANCE UPSLOPE SHOWERS CAN BE EXPECTED
ACROSS THE NORTHEAST MOUNTAINS TODAY AND THIS EVENING. HAVE
MENTIONED SLIGHT CHANCE THUNDER ACROSS THE NORTHEAST MOUNTAINS
THROUGH 5 PM...AS IT STILL CAN`T BE RULED OUT. BUT ONCE THE WEST
NORTHWEST FLOW SETS IN THIS EVENING...INSTABILITY WILL BE VERY
LIMITED. SO HAVE PULLED BACK ON THE THUNDER POTENTIAL TO JUST THE
EAGLE CAPS...SOUTHERN GRANT...CROOK...AND DESCHUTES COUNTY FROM 5 TO
8 PM THIS EVENING. WEBER
&&
.PREV DISC... /ISSUED 255 AM PDT THU SEP 18 2014/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...AN UPPER LEVEL TROUGH
IS NEAR THE COAST AS IT SLOWLY SHIFTS EASTWARD. THE TROUGH IS
SPLITTING AS IT MOVES INLAND WITH THE NORTHERN SECTION IN WASHINGTON
AND THE SOUTHERN SECTION IN CALIFORNIA. THERE ARE TWO BANDS OF
PRECIPITATION ON RADAR AND MODELS. ONE IS NEAR THE CASCADES ON THE
EAST SIDE OF THE TROUGH AXIS AND THE SECOND ONE IS IN EASTERN GRANT
COUNTY...WALLOWA COUNTY...AND BAKER COUNTY. HRRR SHOWS THE FIRST
BAND REMAINING IN CENTRAL/NORTH CENTRAL OREGON AND CENTRAL
WASHINGTON THIS MORNING. THE SECOND BAND IS ASSOCIATED WITH A JET
STREAK. HRRR SHOWS THIS BAND REMAINING SEPARATE AND MOVING NORTHEAST
OUT OF THE OREGON BY 16Z. THE MORNING FORECAST HAS THE TWO SEPARATE
BANDS...THEN THE FIRST BAND WILL SPREAD ACROSS CENTRAL TO NORTHEAST
OREGON AS THE TROUGH AXIS MOVES ACROSS EASTERN WASHINGTON AND OREGON
THIS AFTERNOON. THE BEST INSTABILITY WILL MOVE FROM CENTRAL TO
NORTHEAST OREGON WHERE THE DIFFLUENCE FROM THE SPLITTING TROUGH IS
ADDED TO THE INSTABILITY AHEAD OF THE TROUGH. ISOLATED THUNDERSTORMS
MAY DEVELOP IN THIS REGION DURING THE AFTERNOON AND EARLY EVENING.
THE TROUGH AXIS WILL BE IN IDAHO BY 6Z/2300 PDT WITH RAIN SHOWERS
ENDING EXCEPT FOR OROGRAPHIC SHOWERS NEAR THE CASCADE CREST. FRIDAY
AND SATURDAY THE UPPER LEVEL RIDGE WILL BUILD OVER THE PACIFIC
NORTHWEST WITH CLEARING SKIES AND WARMING DAYTIME TEMPERATURES.
COONFIELD
LONG TERM...SUNDAY THROUGH WEDNESDAY...00Z MODEL RUNS INDICATE VERY
SIMILAR SOLUTIONS OVER FORECAST AREA AND NORTHEAST PACIFIC WITH A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUING OVER THE PACIFIC
NORTHWEST SUNDAY AND MONDAY. MODELS SHOW CONSISTENT SOLUTIONS FOR
TUESDAY AS WELL WITH THE RIDGE MOVING EAST INTO THE NORTHERN PLAINS
BY DAYBREAK TUESDAY AS THE NEXT LONGWAVE TROUGH SPREADS EASTWARD TO
130-140W. THE GFS IS MORE PROGRESSIVE IN TAKING THE AXIS OF AN OPEN
LONGWAVE TROUGH TO 132W BY TUESDAY AFTERNOON WHEREAS THE ECMWF KEEPS
THE LOWEST HEIGHTS IN THE OVERALL TROUGH NEAR 140W WHERE A CLOSED
LOW WITH MUCH LOWER HEIGHTS DEVELOPS IN THE ECMWF SOLUTION. BOTH GFS
AND ECMWF SHOW A VERY WEAK DISTURBANCE MOVING THROUGH FORECAST AREA
MONDAY NIGHT AND TUESDAY SO I HAVE INCREASED POPS A TAD TO SLIGHT
CHANCE FOR POSSIBLE ISOLATED LIGHT SHOWERS IN THE BLUE MOUNTAINS
MONDAY NIGHT AND TUESDAY. THE TROUGH APPROACHES THE COAST TUESDAY
NIGHT AND SPREADS INCREASING CLOUDS, MOISTURE, AND RAIN TO THE
CASCADES JUST BEFORE DAYBREAK ON WEDNESDAY. THE PRECIPITATION
SPREADS ACROSS FORECAST AREA WEDNESDAY MORNING. AS ALREADY
MENTIONED, THE GFS IS FASTER IN TERMS OF BRINGING THE TROUGH AXIS TO
THE COAST BY LATE WEDNESDAY MORNING WHILE THE ECMWF KEEPS THE TROUGH
AXIS WELL OFFSHORE. THIS PHASING DIFFERENCE BETWEEN THE TWO MODELS
ON WEDNESDAY WITH RESPECT TO THE PLACEMENT OF THE TROUGH AXIS
RESULTS IN THE ECMWF TAKING LONGER TO SPREAD RAIN TO THE BLUE
MOUNTAINS UNTIL LATE WEDNESDAY NIGHT OR THURSDAY MORNING. AS SUCH
HAVE LOWER CONFIDENCE IN POP FORECAST FOR WEDNESDAY IN THE EASTERN
SECTIONS OF FORECAST AREA. POLAN
AVIATION...12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NEXT 24 HOURS. THERE MAY BE SOME LIGHT SHOWERS AT
KDLS...KRDM...KBDN...KPDT AND KALW TODAY WITH POSSIBLY A
THUNDERSTORM AT KRDM AND KBDN IN THE AFTERNOON AND EVENING. WINDS
WILL BE GENERALLY LIGHT ALTHOUGH GUSTY AND ERRATIC WINDS ARE LIKELY
NEAR ANY THUNDERSTORMS. CIGS AND VISIBILITIES WILL REMAIN ABOVE VFR
DUE TO THE DRYNESS OF THE AIR MASS IN THE LOWER LEVELS THROUGH THIS
EVENING. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 80 55 80 52 / 20 10 0 0
ALW 83 61 80 57 / 20 10 0 0
PSC 85 57 85 51 / 10 10 0 0
YKM 80 56 84 54 / 20 10 0 0
HRI 83 55 85 48 / 10 10 0 0
ELN 80 57 83 52 / 20 10 0 0
RDM 76 43 79 40 / 20 20 0 0
LGD 81 51 79 44 / 20 10 0 0
GCD 78 49 81 47 / 20 10 0 0
DLS 78 58 83 52 / 30 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
89/99/99
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1005 AM CDT THU SEP 18 2014
.UPDATE...
THE FLOOD WATCH HAS BEEN EXPANDED EASTWARD TO INCLUDE MOST OF THE
CWA...EXCLUDING HALL AND CHILDRESS COUNTIES. A LARGE AREA OF
MODERATE RAINFALL CONTINUES TO ENVELOP MUCH OF THE FA...WITH
POCKETS OF HEAVY RAIN. IT APPEARS THE HEAVIEST OF THE RAINFALL IS
GOING TO TEND TO CONVERGE ACROSS OUR SOUTHEAST ZONES OVER THE NEXT
COUPLE OF HOURS...AND FOR THIS REASON WE HAVE DECIDED TO EXPAND
THE FLOOD WATCH EASTWARD. POP...WEATHER AND QPF GRIDS WERE ALSO
ADJUSTED GIVEN CURRENT RADAR TRENDS AND HIGH RESOLUTION MODELS. A
MENTION OF HEAVY RAIN WAS ALSO ADDED TO A GOOD CHUNK OF THE AREA
THIS MORNING...WHILE MAINTAINING THE HEAVY RAIN MENTION ACROSS THE
SOUTHEAST ZONES THIS AFTERNOON. UPDATED PRODUCTS HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 630 AM CDT THU SEP 18 2014/
AVIATION...
FLYING WEATHER FOR VFR PILOTS WILL BE A DISAPPOINTMENT NEXT 24
HOURS. WIDESPREAD RAINFALL WITH EMBEDDED TSTMS WILL LIKELY PERSIST
MUCH OF THE FCST PERIOD. WE MAY SEE SOME PERIOD OF MVFR/VFR AT
KLBB BUT THIS IS LIKELY ONLY TO EXIST BETWEEN STORMS AS WIDESPREAD
RAINFALL IS EXPECTED THIS MORNING WITH PERHAPS AN AFTERNOON BREAK
THEN MORE AGAIN TONIGHT. IFR AIRCRAFT SHOULD BE IMPACTED MUCH LESS
HEAVILY THOUGH MANEUVERING AROUND CONVECTIVE CELLS WILL BE
NECESSARY.
PREV DISCUSSION... /ISSUED 322 AM CDT THU SEP 18 2014/
SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING WEST TO EAST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE
DISTURBANCE PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE
SFC WILL VEER TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD
FRONTAL PASSAGE /WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/.
THIS COLD FRONT WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH
SUNDAY...WITH A NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 63 74 61 82 / 70 60 70 60 30
TULIA 78 64 77 63 80 / 70 50 70 60 50
PLAINVIEW 78 64 77 63 80 / 90 60 70 60 50
LEVELLAND 77 65 76 63 81 / 80 70 70 60 40
LUBBOCK 78 67 77 65 80 / 90 70 70 60 50
DENVER CITY 77 66 78 64 84 / 80 70 70 60 40
BROWNFIELD 77 67 78 64 83 / 80 70 70 60 40
CHILDRESS 84 67 83 67 80 / 70 50 50 60 60
SPUR 80 67 80 65 82 / 90 60 50 60 50
ASPERMONT 83 69 85 69 85 / 80 60 50 60 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>044.
&&
$$
05/23
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
639 AM CDT THU SEP 18 2014
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...CONVECTION TO THE NNW OF THE VCT TERMINAL CONTINUES
TO SINK TO THE SSE THIS MORNING. HAVE INCLUDED VCSH REMARKS AS
CONFIDENCE IS NOT HIGH THAT THIS ACTIVITY WILL DIRECTLY IMPACT THE
TERMINAL. INTERMITTENT MVFR CIGS/VSBYS WILL BE POSSIBLE AT ALI/LRD
FOR A FEW HOURS THIS MORNING BEFORE A RETURN TO VFR CONDITIONS.
WEAK S/W TROUGH WILL CONTINUE TO SLIDE TO THE SE TODAY...WITH
ADDITIONAL CHANCES FOR SHOWERS AND STORMS. HAVE INCLUDED VCTS
REMARKS AT ALI/CRP/VCT WITH BEST CHANCES AT THE VCT TAF SITE.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT THU SEP 18 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...AREA OF SLOW MOVING SHOWERS
AND THUNDERSTORMS ASSOCIATED WITH SHORTWAVE TROUGH CONTINUES TO
SLOW SAG TO SOUTH THIS MORNING. LATEST HRRR KEEPS THIS ACTIVITY
NORTH OF THE REGION AS THE MORNING PROGRESSES...BUT WILL CONTINUE
TO MONITOR TRENDS WITH THIS COMPLEX. UPPER DISTURBANCE WILL SHIFT
TO THE SOUTHEAST TODAY. THE BEST SUPPORT AND LOW LEVEL CONVERGENCE
WILL REMAIN OVER THE VICTORIA CROSSROADS REGION...AND HAVE PLACED
THE HIGHEST POPS OVER THIS AREA. FURTHER TO THE WEST AND SOUTHWEST
SUFFICIENT MOISTURE WILL REMAIN IN PLACE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS. AS WITH THE LAST SEVERAL DAYS...THREAT
FOR LOCALLY HEAVY RAIN WILL BE POSSIBLE. PW VALUES WILL REMAIN AT
OR ABOVE 2 INCHES TONIGHT INTO FRIDAY. ANOTHER WEAK DISTURBANCE IN
NW FLOW ALOFT WILL MOVE ACROSS CENTRAL TEXAS ON FRIDAY...RESULTING
IN ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. TEMPERATURES
TODAY AND FRIDAY WILL RANGE FROM THE MIDDLE 90S OVER THE RIO
GRANDE PLAINS WITH UPPER 80S TO LOWER 90S OVER THE VICTORIA
CROSSROADS WHERE BETTER CHANCES OF RAIN WILL EXIST.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...SURFACE HIGH PRESSURE
BEGINS TO NUDGE INTO THE REGION FROM THE NORTHEAST WITH PWATS
EXPECTED TO SLOWLY DECLINE THROUGH THE WEEKEND. NONETHELESS...THERE
WILL STILL BE ENOUGH MOISTURE AVAILABLE TO LEAD TO ISOLATED TO
SCATTERED DIURNAL ACTIVITY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
CONCERNING THE ADVERTISED COLD FRONT NEXT WEEK...MODEL DISAGREEMENTS
CONTINUE. THE NEXT UPPER TROUGH WILL SWING EAST THROUGH THE CENTRAL
PLAINS WITH THE ASSOCIATED FRONTAL BOUNDARY TO FOLLOW. THE ECMWF
KEEPS THE MAIN TROUGH WELL TO THE NORTH WHICH WOULD SUGGEST LITTLE
TO NO AFFECT FROM THE BOUNDARY. HOWEVER THE GFS AND CMC MAINTAIN A
SLIGHTLY SOUTHERN POSITION WHICH WITH THE AIDE OF A SURFACE LOW
ACROSS THE CENTRAL PLAINS...WOULD HELP ELONGATE THE FRONTAL BOUNDARY
INTO SOUTH TEXAS. WITH A MORE NORTH TO SOUTH FLOW IN
MIDLEVELS...WILL CONTINUE TO BRING THE FRONT THROUGH THE REGION
MONDAY NIGHT/TUESDAY KEEPING A SLIGHT CHANCE THROUGH TUESDAY BEFORE
DRYING THINGS OUT FOR THE REST OF THE WEEK. AS FOR
TEMPERATURES...KEPT NEAR TO SLIGHTLY ABOVE GUIDANCE THROUGH THE
PERIOD...WITH THE EXCEPTION OF COOLER CONDITIONS WITH THE FRONTAL
BOUNDARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 77 91 76 91 75 / 20 40 20 20 20
VICTORIA 75 91 74 93 75 / 30 50 10 30 10
LAREDO 77 96 78 96 78 / 20 30 20 30 20
ALICE 76 93 74 93 75 / 20 40 10 30 10
ROCKPORT 78 90 78 90 78 / 30 40 20 20 20
COTULLA 76 95 76 96 76 / 30 30 20 30 10
KINGSVILLE 76 93 75 93 75 / 20 40 10 30 10
NAVY CORPUS 80 89 79 91 79 / 20 40 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
630 AM CDT THU SEP 18 2014
.AVIATION...
FLYING WEATHER FOR VFR PILOTS WILL BE A DISAPPOINTMENT NEXT 24
HOURS. WIDESPREAD RAINFALL WITH EMBEDDED TSTMS WILL LIKELY PERSIST
MUCH OF THE FCST PERIOD. WE MAY SEE SOME PERIOD OF MVFR/VFR AT
KLBB BUT THIS IS LIKELY ONLY TO EXIST BETWEEN STORMS AS WIDESPREAD
RAINFALL IS EXPECTED THIS MORNING WITH PERHAPS AN AFTERNOON BREAK
THEN MORE AGAIN TONIGHT. IFR AIRCRAFT SHOULD BE IMPACTED MUCH LESS
HEAVILY THOUGH MANEUVERING AROUND CONVECTIVE CELLS WILL BE
NECESSARY.
&&
.PREV DISCUSSION... /ISSUED 322 AM CDT THU SEP 18 2014/
SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING WEST TO EAST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE
DISTURBANCE PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE
SFC WILL VEER TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD
FRONTAL PASSAGE /WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/.
THIS COLD FRONT WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH
SUNDAY...WITH A NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 63 74 61 82 / 60 60 70 60 30
TULIA 78 64 77 63 80 / 40 50 70 60 50
PLAINVIEW 78 64 77 63 80 / 60 60 70 60 50
LEVELLAND 77 65 76 63 81 / 80 70 70 60 40
LUBBOCK 78 67 77 65 80 / 70 70 70 60 50
DENVER CITY 77 66 78 64 84 / 90 70 70 60 40
BROWNFIELD 77 67 78 64 83 / 90 70 70 60 40
CHILDRESS 84 67 83 67 80 / 40 50 50 60 60
SPUR 80 67 80 65 82 / 60 60 50 60 50
ASPERMONT 83 69 85 69 85 / 60 60 50 60 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>030-033>036-039>042.
&&
$$
99/99/26
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
643 AM CDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERNS TODAY ARE CLOUD TRENDS.
LATEST 08Z SURFACE ANALYSIS SHOWS WEAK COLD FRONT EXTENDING FROM
EASTERN WISCONSIN INTO WESTERN MINNESOTA. LATEST FOG PRODUCT
SATELLITE IMAGERY INDICATES LOW LEVEL STRATUS OVER PORTIONS OF
NORTHERN AND EASTERN HALF OF WISCONSIN AND EAST CENTRAL
MINNESOTA. THIS LOW LEVEL STRATUS IS MOVING SOUTH AND WEST BEHIND
THE WEAK SURFACE FRONT.
THE 18.00Z GFS/NAM AND 18.06Z RAP APPEAR INITIALIZE AND HANDLE
MOVEMENT/EXPANSION OF LOW LEVEL STRATUS WELL INTO WESTERN WISCONSIN
EARLY THIS MORNING/TODAY PER THE 925MB RELATIVE HUMIDITY FIELDS. THE
BIG QUESTION WILL BE HOW LONG WILL THE LOW LEVEL STRATUS HANGS
AROUND THE FORECAST AREA TODAY. THE 18.00Z GFS/NAM AND 18.06Z RAP
SUGGEST THE CLOUDS WILL ERODE DUE TO DAYTIME HEATING AND LIFT BACK
NORTH INTO NORTHERN WISCONSIN AROUND 18Z TODAY. IF LOW LEVEL STRATUS
ERODES LATER IN THE AFTERNOON...THIS WILL HAVE IMPACTS ON FORECAST
HIGH TEMPERATURES FOR TODAY...ESPECIALLY OVER EASTERN PART OF THE
FORECAST AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY INTO SATURDAY
NIGHT. THE LATEST 18.00Z GFS/NAM/ECMWF SHOW DECENT ISENTROPIC LIFT
AT 305K SURFACE BETWEEN 12-18Z FRIDAY AND ASSOCIATED 925-850MB
MOISTURE TRANSPORT INTO THE WESTERN FORECAST AREA. THE COMBINATION
OF ELEVATED INSTABILITY OF 0-6KM MOST UNSTABLE CAPE OF 300-800
J/KG OVER THE WESTERN FORECAST AREA AND THIS LIFT...WARRANTS A
SMALL PRECIPITATION CHANCE OVER THE WESTERN FORECAST AREA BETWEEN
12-18Z FRIDAY.
AFTER THIS INITIAL WEAK IMPULSE IN ASSOCIATION WITH WARM AIR
ADVECTION...THE 18.0ZZ GFS/NAM/ECMWF INDICATE MUCH OF THE
SOUTHERN FORECAST AREA BECOMES CAPPED AFTER 18Z FRIDAY...AS
SHORTWAVE RIDGE BUILDS INTO THE AREA AND FOCUSES LIFT/MOISTURE
TRANSPORT INTO NORTHERN WISCONSIN. HAVE ADJUSTED PRECIPITATION
CHANCES FURTHER NORTH AFTER 18Z FRIDAY. THE CAP BEGINS TO WEAKEN
AFTER 00Z SATURDAY ACROSS THE FORECAST AREA...IN ADDITION SURFACE
FRONT PUSHES ACROSS FORECAST AREA AND DEEP FORCING/MOISTURE
TRANSPORT/CONVERGENCE WILL ALLOW SHOWERS AND THUNDERSTORMS TO
DEVELOP IN THE 00-06Z SATURDAY TIMEFRAME AND MOVE NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT. ANY SEVERE THREAT
WITH THE THUNDERSTORMS LOOKS TO BE CONFINED NORTH OF THE
INTERSTATE 90 CORRIDOR...WHERE THE BETTER INSTABILITY AND SHEAR
WILL BE OVER THE FORECAST AREA. AT THIS TIME...THE SEVERE THREAT
LOOKS TO BE ISOLATED AND THE MAIN THREATS WOULD BE LARGE HAIL AND
DAMAGING WINDS.
SURFACE FRONT/SHORTWAVE TROUGH PUSHES SOUTH AND EAST OF FORECAST
AREA SATURDAY AND TAKING THE BULK OF LIFT AND BETTER INSTABILITY
SOUTH AND EAST OF FORECAST AREA. THE REGION WILL BE UNDER THE
INFLUENCE OF CYCLONIC FLOW SATURDAY...WITH STEEPENING LAPSE RATES
AND A COUPLE HUNDRED ELEVATED CAPE PER BUFKIT SOUNDINGS. SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ACROSS THE FORECAST
AREA. HAVE LEFT SMALL PRECIPITATION CHANCES IN THE FORECAST.
UPPER LEVEL TROUGH BEGINS TO BREAK DOWN OVER THE GREAT LAKES
REGION AND HEIGHTS RISE OVER THE NORTHERN PLAINS LATE SUNDAY INTO
THE MIDDLE OF NEXT WEEK. THE 18.00Z GFS/ECMWF ARE INDICATING
UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES BY 00Z
THURSDAY. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL EARLY TO
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 643 AM CDT THU SEP 18 2014
COMPLEX WEATHER PATTERN OVER THE TAF SITES FOR THE NEXT SEVERAL
HOURS WITH VFR OR IFR CONDITIONS. A COLD FRONT IS MOVING OUT OF
WISCONSIN TOWARD MINNESOTA AT 1130Z. AN IFR CLOUD DECK WITH SOME
EMBEDDED IFR VSBYS HAS MADE ITS WAY WESTWARD TO THE MN/WI BORDER.
THIS HAS MADE STEADY WESTWARD PROGRESS OVERNIGHT.
AT KLSE...RIVER VALLEY STRATUS AND FOG WERE FOUND IN THE VALLEY
AND NOW WITH THE IFR CLOUD DECK MOVING OVER THE TOP...BELIEVE IT
WILL SIMPLY REINFORCE THE IFR CONDITIONS...MAKE IT LESS LOCAL TO
THE RIVER VALLEY...AND IMPACT AVIATION THROUGH THE MORNING.
AT KRST...THE WESTWARD PUSH TO THE IFR CIGS AND FRONT SHOULD SLOW
SOME WITH SUNRISE AND MIXING INCREASING. BUT IT IS STILL EARLY
AND HAVE DECIDED TO AT LEAST ADDRESS THE POSSIBILITY THAT THE IFR
CLOUD DECK COULD REACH KRST BEFORE HALTING ITS WESTWARD
PROGRESSION VIA A TEMPO IFR GROUP. CONFIDENCE IS LOWER ON
KRST...IF THE DECK CONTINUES WEST...THE MORNING TAF WILL BE VERY
SIMILAR TO KLSE WITH IFR THROUGH 16-17Z PREVAILING. UPDATES WILL
BE FORTHCOMING AS CONFIDENCE IN A SCENARIO GROWS.
BOTH SITES SHOULD SEE LIFTING CEILINGS BY LATE MORNING WITH A
DECREASE IN CLOUD THIS AFTERNOON AND A RETURN TO VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
529 AM MDT THU SEP 18 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 526 AM MDT THU SEP 18 2014
NEBRASKA TAFS...AREAS OF IFR CEILINGS AND VISIBILITIES IN LOW
CLOUDS AND FOG THROUGH 9 AM...OTHERWISE VFR PREVAILS. WIND GUSTS
OF 20 TO 30 KNOTS LATE THIS MORNING AND THIS AFTERNOON.
WYOMING TAFS...VFR PREVAILS. WIND GUSTS OF 20 TO 30 KNOTS LATE
THIS MORNING AND THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS RENO NV
309 PM PDT THU SEP 18 2014
.SYNOPSIS...
SMOKE FROM THE KING FIRE WILL AFFECT PARTS OF THE REGION THROUGH
TONIGHT. AS WINDS SHIFT TO THE EAST FROM FRIDAY THROUGH THE
WEEKEND, SMOKE WILL REMAIN WEST OF THE SIERRA CREST. LOW PRESSURE
MOVING INTO NORTHERN CALIFORNIA WILL BRING A CHANCE OF
THUNDERSTORMS TODAY AND TONIGHT. THUNDERSTORM CHANCES WILL
DECREASE FRIDAY AS THIS LOW MOVES FARTHER SOUTH.
&&
.SHORT TERM...
UPPER LEVEL LOW CONTINUES TO PUSH DOWN ALONG THE CALIFORNIA COAST
THROUGH TONIGHT WITH SOUTHWEST FLOW ALOFT. TEMPERATURES WILL BE A
BIT COOLER TODAY AND FRIDAY AS THE LOW BRING DOWN TEMPERATURES
ALOFT. BY FRIDAY, THE LOW BECOMES CUT OFF FROM THE MAIN JET OVER
THE PAC NORTHWEST AND MEANDERS AROUND THE CALIFORNIA COAST THROUGH
THE WEEKEND.
SMOKE FROM THE KING FIRE WEST OF TAHOE WILL CONTINUE TO FLOW INTO
THE NORTH TAHOE AND RENO AREAS THROUGH THIS EVENING AND TONIGHT.
BY TONIGHT, WINDS WILL BEGIN TO SHIFT TO THE EAST, HELPING TO
IMPROVE THE SMOKEY SKIES FRIDAY AND SATURDAY. THERE IS MEDIUM TO
HIGH CONFIDENCE THAT THE WINDS WILL REMAIN OUT OF THE EAST THROUGH
THE WEEKEND WITH IMPROVING CONDITIONS OVER WESTERN NEVADA. AS FOR
LAKE TAHOE THIS WEEKEND, SATURDAY LOOKS PRETTY GOOD FOR EASTERLY
WINDS KEEPING SMOKE OUT OF THE BASIN, ALTHOUGH BY SUNDAY THERE MAY
BE SOME SMOKE CREEPING BACK INTO THE BASIN LATE IN THE DAY AS
LIGHT WESTERLY WINDS RETURN. THIS COULD IMPACT WEEKEND EVENTS
AROUND LAKE TAHOE
AS THE LOW CONTINUES TO DROP SOUTH, A FEW SHOWERS AND
THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND TONIGHT IN
WESTERN NEVADA. DEFORMATION ZONE OF THE LOW WILL HELP TO CREATE
SOME ADDED LIFT IN THE ATMOSPHERE. ANY PRECIPITATION FROM THESE
SHOWERS WILL ALSO HELP TO GET SOME OF THE PARTICULATES OUT OF THE
AIR AS WELL. THERE MAY BE AN AREA OF HEAVIER PRECIPITATION IN
WESTERN NEVADA TONIGHT, THE NAM AND HRRR ARE ACTUALLY STARTING TO
SHOW SOME AREAS OF HEAVIER PRECIPITATION ASSOCIATED WITH THIS
DEFORMATION ZONE OVERNIGHT. WE WILL HAVE TO KEEP A CLOSE EYE ON
THIS POTENTIAL.
BY FRIDAY AND SATURDAY, THE LOW DROPS OFF THE CA COAST SLIGHTLY, BUT
HELPS TO BRING SOUTHEAST FLOW AND INCREASED CONVERGENCE/MOISTURE OVER
THE EASTERN SIERRA. THIS WILL KEEP A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST MAINLY SOUTH OF HIGHWAY 50 ON FRIDAY
AND CREEPING UP INTO THE TAHOE BASIN BY SATURDAY AND SATURDAY
NIGHT. HOON
.LONG TERM...SUNDAY THROUGH THURSDAY...
THE MAIN CHANGE TO THE LONG TERM FORECAST WAS TO INCREASE CHANCES
FOR PRECIPITATION ON SUNDAY. THE CLOSED LOW THAT WAS SITTING OVER
SOUTHERN CALIFORNIA WILL BEGIN TO OPEN AND LIFT TOWARD THE NORTHEAST
SUNDAY INTO MONDAY. AS IT LIFTS, WRAP AROUND MOISTURE FORMS A BAND
OF PRECIPITATION ALONG A DEFORMATION AXIS IN THE NORTHEAST QUADRANT
OF THE LOW. YESTERDAY, ONLY THE EC WAS SHOWING THIS SOLUTION, AND
WHILE IT IS STILL THE MOST ROBUST, OTHER OPERATIONAL MODELS ARE NOW
COMING AROUND TO THIS SOLUTION AS WELL. THEREFORE, POPS WERE
INCREASED FOR THE PERIOD, THOUGH DEPENDING ON MODEL TRENDS, IT IS
POSSIBLE THEY WILL NEED TO BE BOOSTED FURTHER. WHILE NOT OVERLY
IMPRESSIVE, THUNDERSTORMS ARE A POSSIBILITY SUNDAY AFTERNOON DUE TO
FORCING FROM THE LOW AND MID-LEVEL INSTABILITY.
SHORTWAVE RIDGING BUILDS IN BEHIND THE EXITING LOW MONDAY INTO
TUESDAY FOR DRY AND STABLE CONDITIONS AND TEMPERATURES NEAR NORMAL.
SOUTHWEST WINDS ARE EXPECTED TO INCREASE WEDNESDAY AND THURSDAY
AHEAD OF AN APPROACHING COLD FRONT AND DEEP TROUGH. IF THE KING FIRE
IS STILL ACTIVELY BURNING, THIS WILL LIKELY BRING ANOTHER LARGE PUSH
OF SMOKE INTO THE SIERRA AND NORTHWEST NEVADA, BUT TIME WILL TELL
HOW THE FIRE EVOLVES. THERE IS DECENT LARGE SCALE MODEL AGREEMENT
WITH THE TROUGH PUSHING INTO NORTHEAST CALIFORNIA AND NORTHWEST
NEVADA ON THURSDAY WITH PRECIPITATION AND MUCH COOLER TEMPERATURES
POSSIBLE. DJ
&&
.AVIATION...
THE GREATEST AVIATION CONCERN CONTINUES TO BE SMOKE FROM THE KING
FIRE WITH MOST DRASTIC VISIBILITY RESTRICTIONS FROM THE WEST SIDE OF
TAHOE EXTENDING NORTHEAST THROUGH THE GREATER RENO AREA, PAST
PYRAMID LAKE AND INTO KWMC. BOTH KTRK AND KRNO ARE REPORTING 2SM
VISIBILITY AND WIDESPREAD TERRAIN OBSCURATION IS PRESENT THROUGHOUT
THE AREA. GUSTY SOUTHWEST TO WEST WINDS WILL BECOME MORE
NORTHWESTERLY IN THE LATE AFTERNOON WHICH COULD SHIFT SMOKE INTO
KTVL AND KCXP AS WELL. SMOKE WILL LIKELY DISSIPATE OVERNIGHT AS THE
WINDS LIGHTEN AND TURN TO THE NORTH, AND WITH EASTERLY FLOW FRIDAY
AND SATURDAY, TERMINALS WILL REMAIN SMOKE FREE.
THUNDERSTORMS ARE LOOKING LESS LIKELY THIS AFTERNOON WITH THE BEST
INSTABILITY IN NORTHEAST NEVADA. THERE IS A 15 PERCENT CHANCE AN
ISOLATED STORM COULD POP UP, BUT ANY STORMS THAT DO FORM WOULD BE
SHORT-LIVED WITH THE BIGGEST THREAT GUSTY AND ERRATIC WINDS. DJ
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1103 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF RAIN
SHOWERS TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH
AND IN COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL
AVERAGES TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND
SATURDAY. DRY CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT
PACIFIC WEATHER SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD
MIDWEEK.
&&
.DISCUSSION...AS OF 08:52 AM PDT THURSDAY...RAIN SHOWERS CONTINUE
TO MOVE ACROSS THE REGION WITH THE MID/UPPER LEVEL TROUGH
CURRENTLY PUSHING INTO NORTHERN CALIFORNIA. CANNOT RULE OUT A
THUNDERSTORM OR TWO OVER THE NORTH BAY THIS AFTERNOON WITH A
NEARLY 90KT UPPER LEVEL JET AND SHORT-WAVE MOVING ACROSS THE
REGION. PRECIPITATION CHANCES DIMINISH BY TONIGHT AS THE UPPER LEVEL
SUPPORT SHIFTS SOUTHWARD AND THE TROUGH MOVES FURTHER INLAND. THE
ONGOING FORECAST REFLECTS OUR LATEST ANALYSIS AND NO UPDATES ARE
EXPECTED AT THIS TIME.
AS OF THIS MORNING...THE SANTA CRUZ MOUNTAINS HAVE RECEIVED THE
MOST PRECIPITATION WITH AMOUNTS UPWARDS OF 0.60" DURING THE PAST
12 HOURS. NORTH BAY MOUNTAIN LOCATIONS HAVE REPORTED BETWEEN 0.25"
AND 0.50" WHILE AMOUNTS UP TO 0.25" FELL OVER PORTIONS OF THE
SANTA LUCIA MOUNTAINS DURING THE SAME TIME FRAME.
&&
.PREV DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 11:03 AM PDT THURSDAY...A PACIFIC STORM SYSTEM
IS WORKING ITS WAY TOWARDS THE CENTRAL COAST THIS MORNING. THE
WARM FRONT PORTION OF THIS STORM SYSTEM IS POSITIONED ALONG THE
COAST PROMOTING SCATTERED SHOWERS. SOUTHERLY WINDS ARE ENHANCING
THE LOCAL DEW POINT BUT THE WINDS ARE ANTICIPATED TO SHIFT TO THE
WEST BEGINNING LATER THIS AFTERNOON AS THE STORM SYSTEM CONTINUES
TO PUSH SOUTH.
VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TO PERSIST TODAY
WITH A POSSIBILITY OF A SHOWER BETWEEN 1800 AND 2100Z. SOUTHERLY
WINDS WILL BECOME WESTERLY THIS EVENING.
CONFIDENCE MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY WITH OCCASIONAL SHOWERS POSSIBLE BETWEEN 1800 AND 2300Z.
CONFIDENCE MODERATE.
&&
.MARINE...AS OF 11:03 AM PDT THURSDAY...A STORM SYSTEM CENTERED
APPROXIMATELY 200 MILES OFF OF CAPE MENDOCINO WILL MAINTAIN LIGHT
TO OCCASIONALLY MODERATE SOUTHERLY WINDS ACROSS THE COASTAL WATERS
INTO THE OVERNIGHT HOURS. WINDS WILL BECOME NORTHWEST FRIDAY AS
THE STORM SYSTEM PUSHES SOUTHEAST. A LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL CONTINUE TO IMPACT THE WATERS THROUGH
THIS EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RG/KBB
AVIATION: LARRY
MARINE: LARRY
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1211 PM EDT THU SEP 18 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE THROUGH OUR AREA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL THEN BUILD IN TONIGHT INTO FRIDAY,
BEFORE SHIFTING OFFSHORE FRIDAY NIGHT. A WARM FRONT WILL LIFT TO
OUR NORTHWEST SATURDAY, THEN A COLD FRONT IS EXPECTED TO ARRIVE
LATE SUNDAY INTO MONDAY. THIS FRONT WILL SETTLE TO OUR SOUTH AND
EAST DURING MONDAY, THEN AN EXPANSIVE AREA OF HIGH PRESSURE IS
SCHEDULED TO BUILD IN FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH THE MIDDAY UPDATE, WE ADDED SOME ISOLATED SHOWERS TO THE
FORECAST FOR THE NEXT COUPLE OF HOURS ACROSS PORTIONS OF FAR
SOUTHEASTERN PENNSYLVANIA, FAR NORTHERN DELAWARE, AND CECIL COUNTY
MARYLAND. LATEST RADAR IMAGERY SHOWS A SMALL AREA OF LIGHT SHOWERS
AND SPRINKLES HOLDING TOGETHER AND SLOWLY MOVING EAST INTO THESE
AREAS. IN ADDITION, HOURLY TEMPS AND DEWPOINTS WERE ALSO TWEAKED
THROUGH THE AFTERNOON USING THE LAV/LAMP GUIDANCE TO ACCOUNT FOR
LATEST OBSERVATIONS AND TRENDS.
OTHERWISE, THE MID-ATLANTIC IS LOCATED TOWARD THE BASE OF AN
UPPER TROUGH AS SEEN ON WATER VAPOR SATELLITE IMAGERY. THIS LARGE-
SCALE TROUGH IS ASSOCIATED WITH AN UPPER LOW LOCATED JUST TO THE
EAST OF HUDSON BAY. A COLD FRONT STRETCHING FROM THE GULF OF ST
LAWRENCE SOUTHEASTWARD INTO UPSTATE NY WAS RATHER DIFFUSE ON THE
13Z SFC ANALYSIS. THE COLD FRONT WILL MOVE SOUTHWARD INTO THE MID-
ATLANTIC REGION THIS AFTERNOON.
12Z IAD, APG AND OKX SOUNDINGS ALL OBSERVED A SHALLOW SATURATED
LAYER BETWEEN 800-700 MB WITH MOISTURE TRAPPED BELOW THE MID-LEVEL
SUBSIDENCE INVERSION. MODEST LIFT ASSOCIATED WITH A SHORTWAVE TROUGH
HAS LEAD TO A BAND OF BKN-OVC STRATOCU OVER EASTERN PA, NORTHWEST NJ
AND THE EASTERN MD SO FAR THIS MORNING. TRIED TO TIME EASTWARD
PROGRESSION OF THE TROUGH AND ASSOCIATED STRATOCU IN HOURLY SKY
GRIDS WITH THE MORNING UPDATE. LATEST RAP MODEL, WHICH HAD
INITIALIZED WELL WITH CURRENT CLOUD COVER, HANGS ON TO THE MORNING
CLOUD THE LONGEST INTO THE AFTERNOON OVER SOUTHEASTERN PA AND THE
DELMARVA.
FORECAST MAX TEMPS TODAY IN THE MID 70S ARE ONLY A COUPLE OF DEGREES
BELOW CLIMO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE MID-LEVEL TROF AXIS MOVES OFF THE COAST THIS EVENING. A SURFACE
HIGH BEHIND THE COLD FRONT BEGINS TO BUILD IN ACROSS THE AREA.
TEMPERATURES WILL SETTLE IN THE LOWER 40S ACROSS THE SOUTHERN
POCONOS TO THE MID 50S ACROSS THE COASTAL PLAIN. THIS IS A FEW
DEGREES BELOW NORMAL.
COULD BE A BIT MORE CLOUDINESS ACROSS THE SOUTHERN ZONES, BUT NO
PRECIPITATION IS EXPECTED. SOME PATCHY FOG IS POSSIBLE TOWARD
MORNING.
NORTHWEST WINDS ON THE LIGHTER SIDE WILL SHIFT OUT OF THE NORTH OR
NORTHEAST BY THE FRIDAY SUNRISE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF THE FLOW BECOMING MORE
ZONAL FRIDAY ACROSS THE NORTHERN HALF OF THE NATION. SOME RIDGE
DEVELOPMENT THOUGH OUT WEST LOOKS TO ALLOW A SHORT WAVE TO DIVE INTO
THE MIDWEST SATURDAY, WHICH RESULTS IN A TROUGH AMPLIFYING ACROSS
THE GREAT LAKES AND NORTHEAST SUNDAY THROUGH MONDAY. THIS TROUGH MAY
THEN START TO LIFT OUT LATE TUESDAY. IT APPEARS THE MAIN FRONTAL
PASSAGE OCCURS SUNDAY NIGHT INTO MONDAY, THEN AN EXPANSIVE SURFACE
HIGH IS SCHEDULED TO BUILD ACROSS THE REGION TUESDAY AND WEDNESDAY.
WE USED A GENERAL MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN
BLENDED IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE
THEN MADE AFTER ADDITIONAL COLLABORATION WITH OUR SURROUNDING
OFFICES.
FOR FRIDAY...STRONG SURFACE HIGH PRESSURE SHOULD BE SHIFTING OFF THE
NEW ENGLAND COAST WITH OUR LOW-LEVEL FLOW TURNING EAST AND
SOUTHEAST. THERE IS SOME MOISTURE FORECAST TO BE LINGERING WELL
OFFSHORE ESPECIALLY TO OUR SOUTHEAST, AND THE ONSHORE FLOW INTO OUR
AREA MAY RESULT IN SOME CLOUDINESS ESPECIALLY AT NIGHT. THE
POTENTIAL COMPLICATION IS THAT THE LOW-LEVEL FLOW MAY ACTUALLY VEER
TO MORE SOUTHEAST OR SOUTH THROUGH FRIDAY NIGHT, FOCUSING AN
INCREASE IN MOISTURE NORTHWEST OF THE FALL LINE. IT IS HERE WHERE
PERHAPS SOME STRATUS AND/OR FOG DEVELOPS AS THE LOW-LEVEL MOISTURE
POOLS BENEATH AN INVERSION. AS OF NOW, NOT QUITE SURE HOW MUCH
STRATUS DEVELOPS DUE TO SOME QUESTION ON HOW QUICK THE LOWER LEVELS
MOISTEN UP. FOR NOW, WE INCREASED THE CLOUDS ESPECIALLY AT NIGHT A
BIT MORE. THE COMBINATION OF A NEW AIRMASS AND THE ONSHORE FLOW
SHOULD RESULT IN A COOL DAY ACROSS THE CWA, AND POTENTIALLY BREEZY
ALONG THE COAST.
FOR SATURDAY AND SUNDAY...HIGH PRESSURE BECOMES ELONGATED INTO THE
MID ATLANTIC AS IT WEAKENS AND SHIFTS FARTHER OFFSHORE. THIS OCCURS
AS SOME WAA GETS UNDERWAY AHEAD OF THE NEXT SYSTEM AND HEIGHTS RISE
SOME. THIS SHOULD RESULT IN A NORTHBOUND WARM FRONT THAT MOSTLY
SLIDES JUST TO OUR NORTHWEST, AND WARMER AIR ARRIVES ACROSS OUR CWA
ESPECIALLY SUNDAY WITH A MORE SOUTHWESTERLY LOW-LEVEL FLOW. A SHORT
WAVE DIVING ACROSS THE GREAT LAKES WILL DRIVE A SURFACE LOW
EASTWARD. THE AMPLIFICATION OF THE UPPER-LEVEL TROUGH SHOULD TAKE
THE MAIN SURFACE LOW WELL TO OUR NORTH THOUGH DURING SUNDAY. THE
ASSOCIATED COLD FRONT HOWEVER WILL ARRIVE INTO OUR AREA LATE SUNDAY
WITH SOME SHOWERS. A BAND OF SHOWERS MAY END UP WEAKENING WITH A
SOUTHEASTERN EXTENT DUE TO MUCH OF THE LARGE SCALE LIFT PEELING
AWAY TO THE NORTH. THE INSTABILITY LOOKS LOW THEREFORE WE
CONTINUED WITH NO THUNDER MENTION ATTM. WE GENERALLY FAVORED A
BLEND OF CONTINUITY AND WPC GUIDANCE, WHICH PAINTS SLIGHT CHC TO
LOW CHC POPS ACROSS THE CWA MAINLY SUNDAY NIGHT. MEANWHILE, A LEAD
SHORT WAVE NEAR THE CAROLINAS MAY ORGANIZE A SURFACE LOW ALONG AN
OLD BAROCLINIC ZONE. THIS FEATURE SHOULD TRACK NORTHEAST AND HAVE
NO REAL AFFECT ON OUR SENSIBLE WEATHER.
FOR MONDAY AND TUESDAY...THE MAIN UPPER-LEVEL TROUGH MAY AMPLIFY
SOME MORE ACROSS THE NORTHEAST AND MID ATLANTIC REGIONS MONDAY.
BASED ON SOME RIDGING ENTERING THE PLAINS, AN EXPANSIVE SURFACE HIGH
IS FORECAST TO BUILD ACROSS THE MIDWEST AND GREAT LAKES LATER MONDAY
INTO TUESDAY, WITH THIS FEATURE ARRIVING INTO OUR AREA DURING
TUESDAY. SOME GUIDANCE SHOWS SOME INSTABILITY TYPE SHOWERS OCCURRING
JUST TO OUR NORTH TUESDAY AS ANOTHER SHORT WAVE ROTATES AROUND THE
BASE OF THE UPPER-LEVEL TROUGH. REGARDING POPS, KEPT SOME SLIGHT CHC
TO LOW CHC POPS ESPECIALLY MONDAY MORNING WITH THE DEPARTING COLD
FRONT. WE CARRIED A DRY FORECAST FOR TUESDAY AS THE UPPER-LEVEL
TROUGH MAY START TO LIFT OUT SOME WITH ANY FOCUS GENERALLY TO OUR
NORTH.
FOR WEDNESDAY...AS A RIDGE SLIDES ACROSS THE GREAT LAKES, A
POTENTIALLY STRONG SURFACE HIGH BUILDS ACROSS THE NORTHEAST AND MID
ATLANTIC REGIONS. IF THE CENTER OF THIS HIGH ENDS UP ACROSS NEW
ENGLAND, THEN WE WILL HAVE AN ONSHORE FLOW ONCE AGAIN. AS OF NOW,
LEANED MUCH CLOSER TO THE 00Z WPC GUIDANCE FOR ALL WEATHER ELEMENTS.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS
VFR TDA AND TNGT. STRATOCU BETWEEN 5-9 KFT PROGRESSES EASTWARD
ACROSS THE TERMINALS TDA. NW WINDS UNDER 10 KT TODAY WILL VEER TO
THE N THIS EVE AND NE BY EARLY FRI MRNG.
OUTLOOK...
FRIDAY...VFR THROUGH THE DAY, HOWEVER SOME LOW CLOUDS OR EVEN SOME
FOG COULD DEVELOP OVERNIGHT WITHIN AN ONSHORE FLOW. OUR CONFIDENCE
IS ON THE LOWER SIDE.
SATURDAY AND SUNDAY...SOME LOW CLOUDS AND/OR SOME FOG TO START EACH
DAY, OTHERWISE MOSTLY VFR. A COLD FRONT ARRIVES SUNDAY NIGHT WITH
POSSIBLE SHOWERS AND LOCAL SUB-VFR CONDITIONS.
MONDAY...SOME SHOWERS POSSIBLE ESPECIALLY IN THE MORNING, OTHERWISE
MOSTLY VFR WITH A WIND SHIFT TO THE NORTHWEST.
&&
.MARINE...
BUOY 44065 CAME BACK ON LINE ABOUT 10 PM LAST NIGHT. HOPEFULLY BUOY
44025 WILL NOT BE FAR BEHIND.
TODAY...LONG PERIOD SWELLS GENERATED BY EDOUARD CONTINUE TO REACH
THE EAST COAST TODAY. LATEST OBS SHOW 13-14 SEC WAVE PERIODS THIS
MORNING. SEAS EXPECTED TO REMAIN JUST BELOW SCA LEVELS WIT WAVE
HEIGHTS ARE 4 FT WHILE NORTHERLY WINDS WILL BE AROUND 10 KT
(GUSTING TO 20 KT LATE IN THE DAY).
TONIGHT...SWELLS ARE STILL FORECAST TO BE WITH US THROUGH TONIGHT.
SEAS WILL BE LESS THAN 4 FEET. LIGHT NORTHERLY WINDS WILL INCREASE
TO 20 KT OVERNIGHT ESPECIALLY ACROSS THE NORTHERN WATERS.
OUTLOOK...
FRIDAY...A NORTHEASTERLY WIND SURGE WITH AN INITIAL TIGHTENING OF
THE PRESSURE GRADIENT AND CAA SHOULD THEN EASE SOME AS THE WINDS
TURN EAST-SOUTHEAST BY LATE IN THE DAY AND AT NIGHT. THE SURGE COULD
BE ENOUGH FOR SOME 25-KNOT GUSTS AND SEAS BUILDING TO 5 FEET ON THE
COASTAL WATERS FOR A TIME. AS OF NOW THE WINDS AND SEAS ARE
MARGINAL AND THEREFORE WILL HOLD OFF ON AN ADVISORY.
SATURDAY AND SUNDAY...THE WINDS SHOULD TURN FROM THE SOUTH DURING
THIS TIME FRAME AS HIGH PRESSURE DEPARTS TO THE EAST. THE NEXT COLD
FRONT ARRIVES SUNDAY NIGHT, HOWEVER AN INCREASE IN THE WINDS SHOULD
OCCUR AHEAD OF IT BUT THEY SHOULD BE BELOW ADVISORY CRITERIA. THE
SEAS HOWEVER COULD BE RIGHT NEAR 5 FEET SATURDAY FROM THE EARLIER
ONSHORE COMPONENT.
MONDAY...THE CONDITIONS SHOULD BE BELOW ADVISORY CRITERIA OVERALL AS
WINDS SHIFT FROM THE NORTH AS HIGH PRESSURE STARTS TO BUILD IN LATE.
&&
.RIP CURRENTS...
IN HOUSE GUIDANCE SUGGESTS A MODERATE RISK TODAY FOR NJ/DE BECAUSE OF
LONG PERIOD SWELLS GENERATED BY EDOUARD.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...KLEIN/KLINE
SHORT TERM...KRUZDLO
LONG TERM...GORSE
AVIATION...GORSE/KLEIN/KRUZDLO
MARINE...GORSE/KLEIN/KRUZDLO
RIP CURRENTS...KRUZDLO/KLEIN
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
337 PM CDT THU SEP 18 2014
.SHORT TERM...
UPPER TROUGH LOCATED OVER THE NORTHEAST UNITED STATES IS IN THE
PROCESS OF LIFTING OUT INTO THE ATLANTIC OCEAN. THIS HAS ALLOWED FOR
MOISTURE THAT GOT PUSHED INTO THE GULF YSTRY...BACK INTO THE AREA.
ALTHOUGH MOST ONGOING SHOWERS IN THE CWA ARE SOUTH OF THE LA
COAST...A FEW HAVE BEGUN TO DEVELOP OVER INLAND AREAS. MCV CURRENTLY
LOCATED ALONG THE SOUTHERN LA/TX BORDER APPEARS TO BE GRADUALLY
SHIFTING SOUTHEAST...MORESO ON THE COASTAL INTERFACE BETWEEN
VERMILLION BAY AND THE TX BORDER. HRRR DOES SHOW SOME BLOWOVER FROM
THAT FEATURE TO MOVE INTO THE CWA ALONG AND SOUTH OF INTERSTATE 10
DURING THE EVENING HOURS. THE INTENSITY WILL LIKELY BE IN A A
DECAYING PHASE. SO ALTHOUGH POPS ARE HIGHER IN THE FORECAST FOR THIS
EVENING...MOST ACTIVITY SHOULD BE QUITE LIGHT WITH NOT TOO HIGH OF
QPF OUTSIDE OF ISOLATED TO SCATTERED THUNDERSTORMS THAT DEVELOP
BEFOREHAND.
.LONG TERM...
FRIDAY THROUGH THE WEEKEND WILL BE A TRANSITION PERIOD AS SLIGHT
UPPER RIDGING TRANSLATES ACROSS THE SOUTHERN CONUS BEFORE THE NEXT
TROUGH MOVES ACROSS THE GREAT LAKES. THIS WILL SUPPRESS MOST
CONVECTION AND HAVE LIMITED CONVECTION FRIDAY THROUGH SUNDAY WITH
ONLY COASTAL AREAS SEEING ANY STORMS. GFS AND ECMWF STILL SHOWING
THE NEXT SOMEWHAT DECENT COLD FRONT MOVING INTO THE AREA EARLY NEXT
WEEK AS THE AFOREMENTIONED TROUGH DIGS INTO THE SOUTHEAST.
TEMPS MAY COOL OFF A FEW DEGREES WITH THE POSSIBILITY IF LOWER 60S
FOR MORNING LOWS IN THE SOUTHWEST MS ZONES. RAIN CHANCES WILL BE LOW
DURING THAT PERIOD AS WELL.
MEFFER
&&
.MARINE...
LIGHT EASTERLY FLOW OF 5 TO 10 KNOTS AND SEAS OF 1 TO 2 FEET WILL BE
FOUND OVER THE WATERS TODAY AND TONIGHT. GRADIENT FLOW WILL INCREASE
BEGINNING TOMORROW WITH A PERIOD OF EXERCISE CAUTION CONDITIONS
EXPECTED OVER THE GULF COASTAL WATERS BY LATE TOMORROW AFTERNOON AND
PERSISTING INTO SATURDAY EVENING. THIS INCREASED EASTERLY FLOW WILL
BE IN RESPONSE TO A WEAK LOW PRESSURE SYSTEM MOVING OFF THE TEXAS
COAST AND THEN PUSHING EASTWARD ACROSS THE CENTRAL GULF TOWARD
FLORIDA COMBINED WITH HIGH PRESSURE BUILDING SOUTHWESTWARD ALONG THE
APPALACHIANS. WITH STRONGER WINDS IN PLACE...SEAS WILL
CORRESPONDINGLY RISE TO AROUND 3 TO 5 FEET FRIDAY NIGHT.
SOME HIGHER THAN NORMAL TIDES WILL ALSO BE POSSIBLE BY SATURDAY
GIVEN THE PERSISTENT STRONG ONSHORE FLOW. TIDES WILL BE MOST
ELEVATED ALONG EAST FACING SHORES. AS THE LOW PULLS EAST OF THE
AREA...THE GRADIENT WILL RELAX THROUGH THE DAY ON SUNDAY...WITH A
RETURN TO LIGHTER EASTERLY FLOW OF 5 TO 10 KNOTS FOR MONDAY. SEAS
WILL ALSO FALL BACK TO 2 TO 3 FEET BY MONDAY. THESE CONDITIONS WILL
PERSIST THROUGH TUESDAY. 35
&&
.AVIATION...
EXTENSIVE CIRRUS SHIELD THIS AFTERNOON ACROSS THE AREA. THERE IS
STILL ENOUGH HEATING GOING ON TO TRIGGER SOME ISOLATED WEAK
CONVECTION ACROSS THE AREA...ALTHOUGH NO LIGHTNING REPORTED YET.
MAIN CONVECTION IS OVER SOUTHEAST TEXAS AND THE GULF OF MEXICO...AS
WELL AS SOUTHERN ARKANSAS AND NORTH CENTRAL MISSISSIPPI. MESOSCALE
MODELING TENDS TO PICK UP ONE OF THESE AREAS...BUT NOT BOTH. IN
EITHER CASE...ANY SIGNIFICANT AREAL COVERAGE IS LIKELY TO HOLD OFF
UNTIL AFTER SUNSET...AND WILL CARRY VCTS IN MOST TERMINALS
OVERNIGHT...WITH THE EXCEPTION OF KGPT AND KASD. HIGH AND MID CLOUDS
SHOULD HANG IN OVERNIGHT WHICH MAY PRECLUDE A REPEAT OF FOG/LOW
CLOUD DEVELOPMENT EARLY FRIDAY MORNING. 35
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT AND SUPPORTING USCG SSW OF PASCAGOULA.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 66 87 67 88 / 30 0 10 10
BTR 68 86 70 87 / 50 10 10 10
ASD 74 84 76 87 / 30 20 10 10
MSY 73 84 76 89 / 50 20 10 10
GPT 75 87 76 86 / 30 20 10 10
PQL 74 87 75 87 / 20 20 10 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
330 PM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM EDT THU SEP 18 2014
UPPER LEVEL PATTERN TRANSITIONS FROM NORTHWEST FLOW ON BACK SIDE OF
TROUGHING OVER EASTERN CANADA TO MORE ZONAL FLOW BY THIS WEEKEND.
MAIN REASON THIS OCCURS IS 125+ KT H25 JET STREAK PLOWING ACROSS
PACIFIC TOWARD BRITISH COLUMBIA AND PACIFIC NORTHWEST. AS THIS JET
ENERGY REACHES NORTHERN PLAINS ON FRIDAY IT WILL HELP DEVELOP TROUGH
ALOFT OVER NORTHERN ONTARIO AND THE LK SUPERIOR REGION. INITIAL WAVE
ON LEADING EDGE OF THIS TROUGH WORKS THROUGH FRIDAY NIGHT INTO
SATURDAY MORNING AND THIS SHOULD BE WHEN MAJORITY OF RAIN OCCURS.
AT THE SFC...A TROUGH WITH A WIND SHIFT AND LOW-LEVEL DRYING WILL
MOVE THROUGH. ANOTHER SHORTWAVE IS FORECAST TO SWING THROUGH
SATURDAY NIGHT INTO SUNDAY MORNING. A STRONGER SFC COLD FRONT
WILL ACCOMPANY THAT SHORTWAVE. WARMER THAN NORMAL TEMPS FRIDAY NIGHT
INTO SATURDAY...BEFORE TEMPERATURES FALL BACK BELOW NORMAL ON SUNDAY.
LOW TEMPS ON FRIDAY NIGHT MAY NOT FALL BLO 60 DEGREES IN SOME AREAS
AS THE WARM SOUTH/SOUTHWEST WINDS PERSIST. THOUGH THERE COULD BE LOW
CLOUDS AROUND TO START THE DAY ON SATURDAY...APPEARS THERE WILL BE
ENOUGH MIXING BY LATE MORNING/EARLY AFTN TO RESULT IN MIXING HEIGHTS
BUILDING TO AT LEAST TO H9/H875 WITH HIGHS POTENTIALLY WELL INTO THE
70S IF THERE IS AT LEAST PARTIAL SUNSHINE. MUCH DIFFERENT STORY ON
SUNDAY WITH HIGHS NEAR LK SUPERIOR BARELY REACHING ABOVE 50 DEGREES
AND ONLY INTO THE 50S FARTHER INLAND AND OVER SOUTHERN CWA AND NEAR
LK MICHIGAN. NOTHING TOO HIGH IMPACT IN TERMS OF NORTH TO NORTHWEST
WINDS IN WAKE OF THE COLD FRONT ON SUNDAY...WITH 20-30 MPH ON LK
SUPERIOR AND NEAR THE SHORE...NOTHING TOO ATYPICAL FOR SEPTEMBER.
BACK TO THE IMPACTS TIED TO SYSTEM MOVING THROUGH FRIDAY NIGHT
THROUGH SATURDAY. DOES NOT APPEAR THAT HEAVY RAIN WILL BE A LARGE
THREAT WITH THIS SYSTEM...MAINLY BECAUSE THE GREATEST SURGE OF H85
THETA-E ADVECTION AND PWATS NEAR 200 PCT OF NORMAL ONLY OCCURS FOR
BRIEF PERIOD ON FRIDAY NIGHT BEFORE THE H85 JET VEERS MORE WEST BY
12Z SATURDAY. SOUTH WINDS AHEAD THE INITIAL LOW PRESSURE SYSTEM AND
SFC TROUGH WILL BE STRONG AND GUSTY FRIDAY EVENING. SOUNDINGS SHOW
STABLE PROFILE BLO AN INVERSION AT H9-H85...BUT BLYR WINDS ARE STILL
IN THE 40-50 MPH RANGE. PRESSURE FALLS OVER EASTERN LK SUPERIOR TO
JAMES BAY WILL ENHANCE THE SOUTH WINDS. OVERALL...COULD SEE SOUTH
WINDS GUSTING OVER 35 MPH VCNTY OF EASTERN LK SUPERIOR AND NORTHERN
LK MICHIGAN WITH SOME GUSTS 30-35 MPH ON THE LAND AREAS OF THE
EASTERN CWA. ATTM THINK THE WIND GUSTS SHOULD STAY BELOW ADVY
CRITERIA OF 45 MPH.
ADDITIONAL IMPACT COULD BE STRONG OR POSSIBLE SEVERE STORMS ON
SATURDAY AFTN AS SFC TROUGH CROSSES THE AREA ALONG WITH SHORTWAVE
AND PUSH OF MID-LEVEL MOISTURE. MLCAPES UP OVER 1500J/KG AND WITH
THE UPPER TROUGH IN THE VCNTY...0-6KM SHEAR IS OVER 40 KTS. NAM
QUITE AGGRESSIVE DEPICTING BUILD UP OF INSTABILITY...WHILE THE GFS
AND ECMWF ARE NOT AS MUCH. SREF PROBABILITIES OF MUCAPE OVER
1000J/KG ALONG WITH SHEAR OVER 30 KTS SHOW SOME INCREASE 15-21Z
SATURDAY OVER MAINLY THE SCNTRL CWA...BUT STILL REMAIN MAINLY BLO 10
PCT. FREEZING LEVEL IS 9-11KFT AND HEIGHT THAT CORES ALOFT WOULD
HAVE TO REACH TO POSSIBLY PRODUCE SEVERE 1 INCH HAIL IS 27-30KFT...
SO LARGE HAIL IS A POSSIBILITY. LOW-LEVEL LAPSE RATES NOT THAT
STEEP...BUT WITH THE DRY AIR H9-H7 AND STRONG WINDS H7-H5...SUPPOSE
STRONG WIND GUSTS COULD MAKE IT TOO SFC. PRIMARY AREA HIGHLIGHTED IN
SPC DAY3 OUTLOOK IS FARTHER EAST AND SOUTH AHEAD OF COLD FRONT
WITHIN SW H85 JET AND WHERE THE SFC DWPNTS ARE WELL INTO THE 60S.
DOES SEEM IF TIMING WORKS OUT WHERE SOME INSTABILITY CAN BUILD OVER
CNTRL UPR MICHIGAN AHEAD OF THE SHORTWAVE...THERE IS ENOUGH OF A
RISK FOR SEVERE...SO WILL CONTINUE TO MENTION IN THE HWO.
INTO SATURDAY NIGHT...COULD STILL SEE SOME TSRA WITH COMBINATION OF
SHORTWAVE AND STEEP H7-H4 LAPSE RATES/COLD POCKET AT H5/. NO STRONG
STORMS EXPECTED THROUGH AS EFFECTIVE SHEAR DIMINISHES TO LESS THAN
20 KTS BY THIS TIME. BESIDES THE CHILL THAT WILL BE IN THE AIR ON
SUNDAY...ANOTHER SHORTWAVE DROPPING THROUGH IN NW FLOW ALOFT AND THE
H85-H5 THERMAL TROUGHING/EXTENSIVE MOISTURE WILL LIKELY BE ENOUGH TO
KICK OFF SOME SHOWERS OVER MAINLY INLAND AREAS. WATER TEMPS OVER
MUCH OF LK SUPERIOR ARE IN THE 6-8C RANGE BASED ON BUOYS AND SHIP
REPORTS. IMMEDIATE NSH AREAS OF SCNTRL LK SUPERIOR MAY BE OVER 10C
IN SOME SPOTS BUT THAT IS LOCALIZED. THEREFORE WITH H85 TEMPS STAYING
ABOVE 0C WILL NOT BE LOOKING AT MUCH LAKE ENHANCEMENT ESPECIALLY AS
LOW-LEVEL FLOW WILL BE TRENDING MORE ANTICYCLONIC THROUGH THE DAY
WITH SFC RIDGE EXPANDING EAST FM THE NORTHERN PLAINS.
EXTENDED...TROUGHING ALOFT DOMINATES EARLY NEXT WEEK. HINT OF
STRONGER SHORTWAVE AND RE-INFORCING SFC TROUGH DROPPING ACROSS
THE UPPER GREAT LAKES ON MONDAY. GFS FARTHER WEST WITH THE WAVE AND
WOULD INDICATE AT LEAST ISOLD SHRA ON MONDAY. ECMWF AND GEM-NH AND
PREVIOUS FORECASTS...KEEP BULK OF WAVE AND MOISTURE TOO FAR EAST TO
RESULT IN MUCH SHRA. SINCE GFS IS ALSO TRENDING THIS WAY WITH 12Z
RUN...WILL KEEP IT DRY ATTM. HIGH PRESSURE INITIALLY AT THE SFC THEN
ALOFT AS WELL BUILDS ACROSS REGION TUESDAY THROUGH THURSDAY. PWATS
LESS THAN 50 PCT OF NORMAL AND AFTN SFC DWPNTS IN THE 30S INDICATE
THERE COULD BE FROST TUESDAY NIGHT/WEDNESDAY NIGHT FOR ALL INLAND
AREAS AND MAYBE EVEN THURSDAY NIGHT FOR INLAND AREAS OF EASTERN CWA.
DAYTIME TEMPS WILL LIKELY BE AT OR ABOVE NORMAL...ESPECIALLY
WEDNESDAY INTO THURSDAY AS WARMER AIR WORKS IN ALOFT /H85 TEMPS OVER
10C/ WITH THE BUILDING UPPER RIDGE. SINCE IT LOOKS LIKE THERE WILL
BE LITTLE IN WAY OF CLOUD COVER EITHER DAY...TEMPS COULD EVEN REACH
THE 70S. NORMAL HIGHS FOR MID-LATE SEPTEMBER ARE IN THE MID TO UPPER
60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 146 PM EDT THU SEP 18 2014
LOW-LEVEL MOISTURE WRAPPING AROUND THE BACKSIDE OF HIGH PRESSURE
OVER THE REGION WILL CONTINUE WITH MVFR CIGS AT IWD...AND BRING MVFR
CIGS TO CMX AND SAW OVERNIGHT THROUGH MUCH OF FRIDAY. AN INCREASING
PRESSURE GRADIENT ACROSS THE REGION WILL ALLOW FOR GUSTY S TO SSW
WINDS AT ALL SITES BEGINNING FRIDAY MORNING...ESPECIALLY AT SAW.
EXPECT GUSTS AS HIGH AS 30KTS DURING THE AFTERNOON HOURS. AN
APPROACHING LOW-LEVEL TROUGH IS EXPECTED TO BRING -SHRA TO WESTERN
UPPER MI DURING THE AFTERNOON...BUT ANY PRECIP SHOULD HOLD OFF AT
IWD OR CMX UNTIL AFTER 18Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KLUBER
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
147 PM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 459 AM EDT THU SEP 18 2014
MAIN FCST CONCERN FOCUSES ON CHCS FOR SHRA FRI THRU SUN AS A SERIES
OF SHRTWVS IN A W-NW FLOW MOVE ACROSS THE UPPER GREAT LAKES REGION.
MODELS COMING INTO BETTER AGREEMENT SHOWING THE FIRST IN A SERIES OF
SHORTWAVES MOVING INTO THE NRN PLAINS ON FRI. STRENGTHENING WAA AND
INCREASINGLY MOIST SW FLOW AHEAD OF THIS SHORTWAVE AND ITS ASSOC
TROUGH/FRONTAL BOUNDARY OVER THE NRN PLAINS WILL INCREASE PWAT
VALUES TO 1.5 INCHES OR HIGHER (MORE THAN 180 PCT OF NORMAL) OVER
THE FCST AREA BY FRI AFTERNOON. MODEL SNDGS INDICATE 500-1000 J/KG
OF MUCAPE AND SHOWALTER INDICES DROPPING AS LOW AS -2 TO -4C BY FRI
AFTERNOON/FRI NIGHT SO WOULD EXPECT AN INCREASING POTENTIAL FOR
ELEVATED TSRA AS THE WARM FRONT APPROACHES LATE IN THE DAY. MODEL
CONSENSUS SUGGESTS THE BEST CHC FOR SHOWERS WL BE OVER THE W HALF
OF THE CWA FRI AFTERNOON AND OVER THE E HALF FRI EVNG...WHEN
ISENTROPIC ASCENT/H925-7 MSTR TRANSPORT AND DEEP LAYER Q-VECT CONV
WL BE MAXIMIZED OVER THOSE AREAS. AS FOR TEMPS...INCREASING CLD COVER
WL HOLD DOWN SFC HI TEMPS INTO THE 60S ON FRI DESPITE INFLUX OF MUCH
WARMER AIR. EXPECT RELATIVELY SMALL TEMP FALL ON FRI NGT WITH STRONG
SW FLOW AND INFLUX OF HIGHER PWAT.
SAT...ANOTHER STRONGER SHRTWV APPROACHING FROM SCNTRL CANADA AND THE
NRN PLAINS WILL PROPEL THE SFC LOW PRES TROUGH AND ASSOC COLD FNT
THRU THE UPR LAKES. THERE MAY BE A BETTER CHANCE OF SHOWERS/TS
AGAIN SAT AFTERNOON MAINLY OVER CENTRAL AND ERN COUNTIES AS DYNAMICS
WITH SHORTWAVE LOOK TO BE IN SYNC WITH DAYTIME HEATING AND TIMING OF
COLD FRONTAL PASSAGE. MLCAPES FCST IN EXCESS OF 1000 J/KG WOULD
SUPPORT THUNDER AND WITH DEEP LAYER SHEAR VALUES OF 45-50 KTS A FEW
STRONG TO POSSIBLY SVR STORMS WOULD NOT BE OUT OF THE QUESTION IF
INSTABILITY IS REALIZED. WILL MENTION THIS POTENTIAL IN HWO.
DEPENDING ON HOW QUICKLY THE SFC COLD FNT PASSES ON SAT AND
POTENTIAL BREAKS IN CLOUD COVER...SOME PLACES MAINLY OVER THE CNTRL
CWA COULD SEE TEMPS RISE WELL INTO THE 70S AS H85 TEMPS ARE FCST TO
PEAK AS HI AS 16-17C.
SAT NGT INTO SUN...ALTHOUGH MODELS SHOW TIMING DIFFERENCES...THEY
SEEM TO BE IN AGREEMENT THAT ADDITIONAL SHRTWVS WILL BE DROPPING
INTO THE GREAT LKS THAT ARE FCST TO DEEPEN AN UPR TROF OVER THE
REGION. THE RESULTING NW CYCLONIC FLOW OVER THE AREA ALONG WITH THE
PASSAGE OF A SECONDARY COLD FRONT SHOULD YIELD A GOOD DEAL OF CLD
COVER...PERIODS OF SHOWERS AND COOLER WX AS H85 TEMPS DROP FM AS HI
AS 15C ON SAT AFTN TO AS LO AS 2-4C BY LATE SUN. IT APPEARS
UNLIKELY THAT H85 TEMPS WL FALL ENOUGH TO REALIZE MUCH OF A LK
ENHANCED COMPONENT TO THE CLDS/SHOWERS SUN AND SUN NGT WITH WSHFT TO
THE N GIVEN FAIRLY CHILLY LAKE SUPERIOR TEMPS OF 8-9C.
EXTENDED...WITH HI PRES AND MUCH DRIER AIR MOVING INTO THE GREAT LKS
EARLY NEXT WEEK...EXPECT DRY WX TO PREVAIL FROM MON THRU WED. MON IS
LIKELY TO BE RATHER COOL...BUT RETURN SW FLOW ON THE NW FLANK OF THE
HI SHIFTING TOWARD THE LOWER LKS WL BRING A WARMING TREND TUE THRU
WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 146 PM EDT THU SEP 18 2014
LOW-LEVEL MOISTURE WRAPPING AROUND THE BACKSIDE OF HIGH PRESSURE
OVER THE REGION WILL CONTINUE WITH MVFR CIGS AT IWD...AND BRING MVFR
CIGS TO CMX AND SAW OVERNIGHT THROUGH MUCH OF FRIDAY. AN INCREASING
PRESSURE GRADIENT ACROSS THE REGION WILL ALLOW FOR GUSTY S TO SSW
WINDS AT ALL SITES BEGINNING FRIDAY MORNING...ESPECIALLY AT SAW.
EXPECT GUSTS AS HIGH AS 30KTS DURING THE AFTERNOON HOURS. AN
APPROACHING LOW-LEVEL TROUGH IS EXPECTED TO BRING -SHRA TO WESTERN
UPPER MI DURING THE AFTERNOON...BUT ANY PRECIP SHOULD HOLD OFF AT
IWD OR CMX UNTIL AFTER 18Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...KLUBER
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
332 PM MDT THU SEP 18 2014
.SHORT TERM...VALID FOR FRI AND SAT...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR TONIGHT
AND ISOLATED STRONG OR EVEN SEVERE STORMS ARE POSSIBLE THROUGH THE
MID EVENING HOURS.
AS OF MID AFTERNOON...THERE HAVE BEEN ENOUGH BREAKS IN CLOUD COVER
TO ENABLE TEMPERATURES IN THE 70S F BEHIND THE EARLIER SHOWERS AND
THUS MLCAPE VALUES HAVE RISEN TO 500-1000 J/KG IN SOUTHWESTERN AND
SOUTH CENTRAL MT PER RAP-BASED SPC MESOANALYSIS DATA. HEIGHT FALLS
HAVE CONTRIBUTED TO SEVERAL STORMS FROM THE ID PANHANDLE TO AROUND
LIVINGSTON AS OF 21 UTC. WE EXPECT FURTHER EXPANSION OF THAT STORM
ACTIVITY AS IT PROPAGATES EAST-NORTHEAST ACROSS THE AREA AND SO WE
ARE CARRYING LIKELY POPS ACROSS SOUTH CENTRAL MT AND NORTH CENTRAL
WY THIS EVENING. RECENT HRRR RUNS APPEAR TO MATCH THIS IDEA AND SO
WE LEANED TOWARD ITS SOLUTIONS TO BUILD THE EVENING FORECAST. SOME
RISK OF STRONG OR EVEN MARGINALLY SEVERE STORMS EXISTS WITH 0-6-KM
BULK SHEAR AROUND 40 KT. WELL-ORGANIZED...PERSISTENT CELLS WITH 50
DBZ HEIGHTS OVER 25 THOUSAND FEET AGL AND/OR BASE VELOCITIES OF 50
KT OR BETTER AT HEIGHTS UNDER 2000 FT AGL MAY NEED SEVERE THUNDER-
STORM WARNINGS...THOUGH WE NEED TO STRESS THAT WILL BE AN ISOLATED
OCCURRENCE AT MOST. A CHANCE OF SHOWERS AND WEAK STORMS WILL EXIST
OVER THE AREA AFTER MIDNIGHT TOO...BUT MAINLY IN SOUTHEASTERN MT.
A DRIER NORTHWEST FLOW ALOFT WILL TAKE OVER FRI AND BY SAT HEIGHTS
ALOFT WILL BE RISING STEADILY AS A RIDGE DEVELOPS OVER THE REGION.
WE ARE NOW ADVERTISING A DRY FORECAST IN MOST AREAS FRI EXCEPT FOR
THE MOUNTAINS AND IN FAR SOUTHEASTERN MT IN THE MORNING AS NONE OF
THE 12 UTC GUIDANCE SIMULATED ANY PRECIPITATION AND SOUNDINGS FROM
THOSE MODELS SHOWED STABLE PROFILES WITH A MID-LEVEL INVERSION. WE
EXPECT HIGHS NEAR 80 F FRI IN A WELL-MIXED AIR MASS AND IN THE 70S
F SAT WITH LIGHTER WINDS IN A MORE SHALLOW BOUNDARY LAYER. SCHULTZ
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
RELATIVELY WARM...LOW-KEY WEATHER IS EXPECTED FOR MUCH OF THE LONG
TERM FORECAST PERIOD AND WE ACCORDINGLY LEANED ON THE CONSENSUS OF
12 UTC GUIDANCE TO BUILD THE GRIDDED FORECAST DATABASE. WE DO HAVE
A CHANCE OF SHOWERS AND STORMS IN PLAY ACROSS NORTH CENTRAL WY AND
PARTS OF SOUTHERN MT SUN NIGHT THROUGH TUE IN RESPECT TO POTENTIAL
FOR A WEAK UPPER-LEVEL LOW MEANDERING ACROSS WY. GUIDANCE HAS BEEN
TRENDING A BIT NORTH WITH THAT FEATURE AND AN IN-HOUSE SET OF MOS-
BASED POP DATA SUPPORTED LOW-END PRECIPITATION CHANCES DURING THAT
TIME FRAME. HOWEVER...THE TRACK OF THE LOW IS QUESTIONABLE BECAUSE
IT WILL BE UNDERCUTTING MEAN RIDGING ALOFT WHICH ITSELF LOOKS LIKE
IT WILL MOVE EASTWARD WITH TIME AS A TROUGH BECOMES ESTABLISHED IN
THE PACIFIC NORTHWEST BY LATE IN THE WEEK. A WARMING TREND WILL BE
IN PLACE WITH WARM AIR ADVECTION AHEAD OF THAT TROUGH. SCHULTZ
&&
.AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS MUCH OF THE
REGION THIS AFTERNOON...AND ARE EXPECTED TO CONTINUE INTO
TONIGHT. MVFR TO IFR CONDITIONS CAN BE EXPECTED WITH THE
THUNDERSTORMS. OBSCURATION OVER AREA MOUNTAINS WILL CONTINUE INTO
TONIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CLEAR FROM WEST
TO EAST EARLY FRIDAY MORNING. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 059/080 052/075 049/076 053/075 054/077 054/078 054/079
61/B 10/U 00/U 12/T 22/T 11/U 12/T
LVM 051/078 043/077 043/076 047/077 049/078 048/079 049/079
61/N 10/U 00/U 12/T 22/T 21/B 22/T
HDN 058/082 050/077 045/078 052/078 052/078 052/080 052/081
61/B 10/U 00/U 12/T 22/T 11/U 12/T
MLS 061/082 051/075 045/076 052/078 054/076 053/079 053/081
42/T 00/U 00/U 01/U 12/T 21/U 11/B
4BQ 061/082 051/076 046/076 053/076 054/075 052/079 052/082
42/T 10/U 00/U 12/T 22/T 21/U 11/U
BHK 060/080 049/074 041/073 047/076 051/072 049/076 050/078
32/T 10/U 00/U 01/U 12/T 21/U 11/B
SHR 058/080 048/076 045/077 051/073 049/075 049/078 050/080
62/T 20/U 00/U 22/T 22/T 21/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1005 AM MDT THU SEP 18 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
UPDATE...ONLY TWEAK TO THE FORECAST THIS MORNING WAS TO INCREASE POPS
SOUTH OF THE MISSOURI RIVER GIVEN ONGOING PRECIP ACROSS SOUTH
CENTRAL MONTANA AND THE HRRR PROGGING SAID PRECIP THROUGH THE
AREA. REMAINDER OF FORECAST UNCHANGED. GILCHRIST
PREVIOUS DISCUSSION...UPPER RIDGE WILL BE FLATTENED TODAY BY A
WEAK SHORTWAVE MOVING ACROSS MONTANA. THIS WAVE WILL INTERACT WITH
A WARM AND UNSTABLE AIRMASS TO PRODUCE A FEW THUNDERSTORMS MAINLY
THIS AFTERNOON AND EVENING. A THERMAL RIDGE WILL ALLOW
TEMPERATURES TO RISE INTO THE 80S IN MOST AREAS... MAY SEE AN
ISOLATED 90 DEGREE HIGH IN THE SOUTH.
A COLD FRONT LATE TONIGHT AND FRIDAY MORNING ALONG WITH A
SHORTWAVE TROUGH ON ZONAL FLOW ALOFT WILL BRING A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS TONIGHT AND FRIDAY. NORTHWEST WINDS MAY
BE STRONG ENOUGH ON FRIDAY FOR A LAKE WIND ADVISORY ON FORT PECK
LAKE.
NORTHWEST FLOW ALOFT WILL BRING COOLER TEMPERATURES ON SATURDAY AS
A HIGH PRESSURE SYSTEM BUILDS INTO THE AREA WITH DRY WEATHER. FORRESTER
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
THERE SEEM TO BE THREE DIFFERENT FEATURES INTERACTING WITH EACH
OTHER THROUGH THE EXTENDED FORECAST PERIOD. FIRST IS THE RIDGE OF
HIGH PRESSURE. NEXT IS THE WEAK CLOSED LOW OR AREA OF WEAK LOW
PRESSURE UNDER THE RIDGE. THE THIRD IS THE LARGE LOW PRESSURE
TROUGH OFF THE WEST COAST OF U S AND CANADA.
MODEL AGREEMENT IS NEAR PERFECT FROM SATURDAY NIGHT THROUGH MONDAY
AFTERNOON KEEPING THE RIDGE OF HIGH PRESSURE OVER THE NORTHERN
HIGH PLAINS AND KEEPING OUR TEMPERATURES WARM AND WEATHER
CONDITIONS DRY.
STARTING MONDAY NIGHT...MODELS BEGIN TO SHOW SOME SLIGHT
DISAGREEMENTS. THE AREA OF WEAK LOW PRESSURE UNDER THE RIDGE VERY
SLOWLY EMERGES FROM THE CENTRAL ROCKIES TO OVER THE NORTHERN HIGH
PLAINS...BUT AS IT DOES SO...THE GFS DISSOLVES IT NEARLY
COMPLETELY EAST OF US BY WEDNESDAY MORNING WHILE THE EC MAINTAINS
IT AND PULLS IT DIRECTLY THROUGH NORTHEAST MONTANA THROUGH
WEDNESDAY AFTERNOON. CONSEQUENTLY...AS THIS MOISTURE APPROACHES
FROM THE SOUTHWEST...THE EC SHOWS A WETTER FORECAST FOR TUESDAY
NIGHT THROUGH WEDNESDAY WHILE THE GFS KEEPS THING DRY. AS THE
DISTURBANCE IS OVERALL WEAK...CHOSE TO BLEND THE TWO CAMPS HERE
AND KEEP THE FORECAST DRY WITH SUB-SLIGHT CHANCE POPS UNTIL
MODELS COME INTO BETTER AGREEMENT.
LASTLY...THE CHAOS ENSUES BEGINNING THURSDAY MORNING AS THE MODELS
TRY TO DEPICT SOME KIND OF PATTERN CHANGE AND LOW PRESSURE STORM
SYSTEM DIVING DOWN FROM THE CANADIAN ROCKIES. CHOSE TO INTRODUCE
SOME BROAD-BRUSHED SLIGHT CHANCE POPS GIVEN THE LIKELIHOOD OF THE
OVERALL PATTERN CHANGE...BUT DETAILS ARE OBVIOUSLY STILL
FORTHCOMING. THE GFS BRINGS DOWN A LARGE AND LONG-WAVE TROUGH
WHILE THE EC KEEPS A MORE NARROW TROUGH...EVENTUALLY CLOSING OFF
AN UPPER LOW AND SEPARATING FROM THE NORTHERN STREAM. WE WILL
LIKELY SEE SOME KIND OF A STRONG COLD FRONTAL SYSTEM APPROACHING
THE REGION BY THIS TIME NEXT WEEK. BMICKELSON
&&
.AVIATION...
FLIGHT CATEGORY: MAINLY VFR. IFR POSSIBLE.
SYNOPSIS: THE UPPER-LEVEL RIDGE IS TOPPLING AS AN UPPER-LEVEL
TROUGH ENTERS FROM THE WEST AND UNSETTLES THE WEATHER THROUGH THE
AFTERNOON HOURS.
SHOWERS & THUNDERSTORMS: SOME VICINITY SHOWERS ARE CURRENTLY
PLANNED AROUND KGDV DURING THE AFTERNOON AND EVENING HOURS. THE
OTHER TERMINALS HAVE A SLIGHT CHANCE FOR SHOWERS BUT CONFIDENCE IS
TOO LOW TO BE DIRECTLY IN THE TAFS. AMENDMENTS WILL BE NEEDED IF A
STRONGER STORM APPROACHES DURING THE AFTERNOON AND EVENING HOURS
WHICH COULD BRING PERIODS OF BRIEF IFR CONDITIONS.
AREA WINDS: SOUTHWEST 5 TO 15 KTS.
GAH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
104 PM CDT THU SEP 18 2014
.SYNOPSIS...
ISSUED AT 355 AM CDT THU SEP 18 2014
SURFACE LOW PRESSURE EXTENDS SOUTH FROM ALBERTA CANADA INTO
NEVADA AND WESTERN ARIZONA. SURFACE HIGH PRESSURE CENTER LOCATED
OVER THE NORTHERN GREAT LAKES. STRATUS IS DEVELOPING AND
EXPANDING FROM NWRN KS INTO SWRN NEBR AND THE SOUTHERN NEBRASKA
PANHANDLE EARLY THIS MORNING. PORTIONS OF CENTRAL AND SOUTHWEST
NEBRASKA REPORTING MAINLY LIGHT FOG 3-5SM WITH LOCALLY DENSE FOG
AT THE KBBW ASOS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU SEP 18 2014
NEAR TERM CONCERN IS DEVELOPMENT OF STRATUS AND FOG DEVELOPMENT
ACROSS PORTIONS OF CENTRAL AND SOUTHWEST NEBRASKA. WHILE LOW
VISIBILITY OF 1/4-1/2SM AT KBBW IS POSSIBLE ACROSS THE
AREA...PREVAILING VISIBILITIES SHOULD RANGE FROM 3-5 SM OR
HIGHER. AREAS TO PATCHY FOG IN THE FORECAST UNTIL 15Z.
OTHERWISE...STRATUS IS FORECAST TO QUICKLY EXPAND NORTHWESTWARD
INTO WESTERN NEBRASKA THIS MORNING. MODELS SHOW A NEARLY
SATURATED H9-H85 LAYER PRESENT WITH RELATIVELY DRY AIR ALOFT. THE
STRATUS IS FORECAST TO EXIT MUCH OF THE PANHANDLE BY 18Z...WHILE
POTENTIALLY PERSISTING OVER PORTIONS OF SWRN INTO CENTRAL
NEBRASKA THROUGH THE AFTERNOON. THIS AGREED UPON BY THE NAM AND
06Z RAP MODEL. THE GFS IS LESS AGGRESSIVE WITH CLOUDS WITH MUCH
HIGHER MOS GUIDANCE. USING 00Z SUPERBLEND OUTPUT...BLENDED WITH
THE 00Z MET GUIDANCE TO REFLECT COOLER HIGHS. WHERE CLEARING
OCCURS ACROSS WRN TIER OF COUNTIES...HIGHS IN THE UPPER 80S
ATTAINABLE. MID 70S FORECAST FOR PORTIONS OF CENTRAL AND SERN
ZONES. ALSO INCREASED PERCENT SKY COVER TO REFLECT MOSTLY CLOUDY
SKIES CENTRAL AND SERN ZONES.
STRONG WARM AIR ADVECTION TONIGHT WITH H85 TEMPS UP TO 25C. THIS
WILL CAUSE LINGERING STRATUS THIS EVENING TO QUICKLY LIFT
NORTHEAST AND DISPERSE AFTER 06Z. LOWS TONIGHT WILL BE MILDER
THAN THE PAST SEVERAL NIGHTS RANGING MAINLY IN THE LOWER 60S.
THERE WILL BE A STRONG INVERSION WITH SOUTH WINDS BECOMING
SOUTHWEST LATE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU SEP 18 2014
FRIDAY WILL BE AN UNSEASONABLE WARM DAY AS A LOW DEVELOPS OVER SW
S DAKOTA ALONG A COLD FRONT STRETCHED FROM THE NORTHERN PLAINS
INTO WYOMING. SOUTHERLY WINDS INCREASE AHEAD OF THE FRONT WHICH
SHOULD MIX OUT ANY BL MOISTURE FOG/STRATUS. 850 MB TEMPS INTO THE
20S C AND MOS GUIDANCE WELL INTO THE 80S AND EVEN SOME LOW 90S.
SHOULD SEE SOME A FEW HIGH CLOUDS FROM STORM SYSTEM TO THE SOUTH
SO KEEP HIGHS CONSERVATIVE. COLD FRONT WILL WILL PUSH ACROSS THE
AREA FRIDAY NIGHT INTO SATURDAY. SOME ELEVATED INSTABILITY
OVERNIGHT...WITH AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY. THE ADDED CLOUDS SHOULD KEEP TEMPS
MILD OVERNIGHT.
COOLER BEHIND THE FRONT WITH PRECIP EXPECTED TO BE PUSHING EAST
IN THE MORNING. SOME SUN BEHIND THE FRONT AND TEMPS REBOUND TO
AROUND 80 ON SATURDAY.
COOL HIGH PRESSURE BUILDS IN OVER THE REST OF THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPS TO SLOWLY TREND DOWN THROUGH MONDAY.
MEANWHILE A DISTURBANCE WILL RIDE ALONG THE FRONT RANGE...HOWEVER
MODELS GENERALLY KEEP PRECIP WEST OF THE CWA.
NEXT WEEK THE HIGH SLIDES EAST WITH RETURN SOUTHERLY FLOW TO
BRING A RETURN OF MORE MOISTURE. A DISTURBANCE SHOULD RIDE ACROSS
THE CENTRAL ROCKIES EARLY MONDAY WITH A CHANCE FOR PRECIP LIFTING
ACROSS THE CWA MONDAY INTO TUESDAY. ALTHOUGH 850 TEMPS ON THE
RISE...CLOUDS /ASSOCIATED WITH THE DISTURBANCE/ LIKELY TO KEEP
TEMPS FROM JUMPING UP TO MUCH. GUIDANCE SUGGEST SEASONAL MID
70S...WHICH SEEMS REASONABLE AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1254 PM CDT THU SEP 18 2014
AN AREA OF STRATUS AND ASSOCIATED MVFR AND LOCAL IFR WILL PERSIST
THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTH CENTRAL
NEBRASKA...SOUTHWARD INTO SOUTHWEST AND PORTIONS OF SOUTH CENTRAL
NEBRASKA. THIS WILL LOWER TONIGHT WITH POSSIBLE LIFR CONDITIONS IN
SPOTS. AS WINDS JUST ABOVE THE SURFACE BECOME SOUTHWEST LATE TONIGHT
AND FRIDAY MORNING...THE LOW CEILINGS SHOULD QUICKLY MOVE OUT OF THE
REGION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1003 AM PDT THU SEP 18 2014
.SYNOPSIS...SOUTHWEST FLOW AHEAD OF A LOW PRESSURE SYSTEM WILL
CONTINUE TO PUSH DRIER AIR INTO THE AREA. ENOUGH MOISTURE WILL STILL
BE IN PLACE FOR A CHANCE OF THUNDERSTORMS OVER MAINLY LINCOLN AND
MOHAVE COUNTIES TODAY. MOST OF THE AREA WILL BE DRY FRIDAY AS A
SOUTHWEST FLOW PERSISTS. SOUTHEAST FLOW WILL PULL MOISTURE BACK INTO
THE AREA OVER THE WEEKEND LEADING TO A CHANCE OF THUNDERSTORMS.
&&
.UPDATE...
DEWPOINTS CONTINUE TO DECREASE FROM WEST TO EAST AS DRY SOUTHWEST
FLOW PUSHES INTO THE REGION. ISOLATED TO SCATTERED THUNDERSTORM
DEVELOPMENT REMAINS POSSIBLE ACROSS LINCOLN...FAR EASTERN
CLARK...AND MOHAVE COUNTY THIS AFTERNOON AND EARLY EVENING /WHERE
LOW LEVEL MOISTURE LINGERS/. WITH LOSS OF HEATING EXPECT ANY
ACTIVITY TO DIMINISH RAPIDLY WITH A DRY OVERNIGHT ANTICIPATED. MADE
A FEW ADJUSTMENTS THIS MORNING TO QUICKLY TREND POPS DOWN THIS
EVENING AND DRY FOR ALL LOCATIONS OVERNIGHT...WHICH CORRELATES WELL
WITH THE 14Z AND 15Z RUNS OF THE HRRR AND OUR LOCAL HIRES MODELS.
&&
.PREVIOUS DISCUSSION...
317 AM PDT THU SEP 18 2014
.SHORT TERM...THROUGH FRIDAY NIGHT...AN UPPER TROUGH WILL MOVE INTO
NORTHERN CALIFORNIA TODAY WITH SOUTHWEST FLOW CONTINUING TO PUSH
DRIER AIR INTO OUR FORECAST AREA. THE MODELS...ESPECIALLY THE
NAM12...CONTINUE TO INDICATE A TONGUE OF PRETTY MOIST AND UNSTABLE
AIR AHEAD OF THIS DRY AIR WHICH WILL KEEP A CHANCE OF THUNDERSTORMS
TODAY OVER MAINLY LINCOLN AND MOHAVE COUNTIES. THE UPPER TROUGH IS
THEN FORECAST TO BECOME A CLOSED LOW JUST OFF THE CENTRAL CALIFORNIA
COAST BY FRIDAY WHILE SOUTHWEST FLOW BRINGS FURTHER DRYING TO OUR
FORECAST AREA. THERE MAY STILL BE JUST ENOUGH LINGERING MOISTURE FOR
A SLIGHT CHANCE OF THUNDERSTORMS FRIDAY OVER EASTERN PORTIONS OF
LINCOLN AND MOHAVE COUNTIES. CANNOT RULE OUT ISOLATED THUNDERSTORMS
OVER THE SIERRA FRIDAY AFTERNOON DUE TO THE PROXIMITY OF THE UPPER
LOW. TEMPERATURES WILL COOL TO NEAR NORMAL BY FRIDAY AS HEIGHTS FALL
DUE TO THE APPROACHING UPPER LOW.
.LONG TERM...MODELS IN GOOD AGREEMENT THAT AN UPPER LEVEL LOW WILL
BE SITUATED NEAR THE SOUTHERN CALIFORNIA COAST SATURDAY MORNING. AS
THE SLOW STARTS TO TRACK SLOWLY NORTHEAST ITS FORECAST TO START
PULLING MOISTURE INTO THE FORECAST AREA FROM SOUTHEAST ARIZONA BY
SATURDAY AFTERNOON. HOW MUCH MOISTURE WILL BE PULLED INTO THE AREA
IS STILL IN QUESTION...BUT HAVE GENERALLY INCLUDED SLIGHT CHANCE
POPS OVER THE ENTIRE REGION WITH THE BETTER CHANCES OVER THE SOUTH
AND EAST. CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE
SATURDAY NIGHT AND SUNDAY AS THE LOW AND ASSOCIATED DYNAMICS TRACKS
THROUGH THE AREA. HAVE UPPED POPS A BIT AS THE MODELS HAVE TRENDED
WETTER OVER THE COUPLE OF RUNS. TEMPERATURES WILL BE CLOSE TO NORMAL
WITH READINGS BELOW NORMAL IN AREAS OF THICKER CLOUD COVER.
THE LOW WILL CONTINUE TO TRACK NORTHEAST SUNDAY NIGHT AND MONDAY
WITH PRECIPITATION CHANCES ENDING ACROSS THE AREA WITH DRIER
CONDITIONS MOVING IN FROM THE WEST. THE SOUTHWEST FLOW WILL INCREASE
BY MONDAY AND TUESDAY AS A TROUGH DEVELOPS OFF THE COAST AND IN TURN
WILL BRING ABOVE NORMAL TEMPERATURES BACK INTO THE REGION.
&&
.AVIATION...FOR MCCARRAN...THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON
IN THE PEACH SPRINGS CORRIDOR WITH DRY AIR MOVING IN FROM THE WEST.
SIGNIFICANT CLOUD COVER IS NOT EXPECTED AT THE TERMINAL TODAY. SOUTH
WINDS UP TO 10 KTS EARLY THIS MORNING WILL TRANSITION TO
EAST/SOUTHEAST UNDER 8 KTS AFTER 14Z BEFORE BECOMING SOUTHWEST NEAR
15 KTS WITH GUSTS AROUND 20 KTS AFTER 21Z.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...LIGHT WINDS WILL BECOME SOUTH/SOUTHWEST 10-20 KTS BY
LATE MORNING OR EARLY AFTERNOON. GUSTS AROUND 25 KTS POSSIBLE IN
PORTIONS OF SOUTHEAST CALIFORNIA AND IN NYE COUNTY. DRY AIR WILL
CONTINUE TO PUSH IN FROM THE WEST TODAY BUT SCATTERED THUNDERSTORMS
ARE EXPECTED IN LINCOLN AND MOHAVE COUNTIES.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS
ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE...PADDOCK
SHORT TERM/AVIATION...HARRISON
LONG TERM...GORELOW
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
224 PM EDT THU SEP 18 2014
.SYNOPSIS...HIGH PRESSURE CENTERED NORTHEAST OF THE GREAT LAKES WILL
EXTEND DOWN THROUGH VIRGINIA AND THE CAROLINAS THROUGH THE
WEEKEND... AS IT SLIDES EAST. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST LATE SUNDAY... THEN MOVE SOUTHEAST THROUGH THE REGION
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 220 PM THURSDAY...
THROUGH TONIGHT: QUIET AND DRY NIGHT FOR MOST. SURFACE MAP SHOWS A
WEAK MSLP PATTERN OVER NC WITH A WEAK INVERTED TROUGH OVER THE WRN
PIEDMONT... HELPING TO FOCUS MOISTURE IN THE LOWEST 5-6 THOUSAND FT
IN THIS AREA AND FOSTERING DEVELOPMENT OF VERY ISOLATED SHALLOW
SHOWERS. THESE SHOULD PERSIST INTO THE EVENING HOURS... GIVEN THIS
WEAK LOW LEVEL MASS CONVERGENCE IN CONJUNCTION WITH WEAK TERRAIN
UPGLIDE... BUT WITH A CAPPING INVERSION EVIDENT AT 775-750 MB AND
WARM/DRY/STABLE AIR ABOVE... EXPECT DEVELOPMENT TO BE STUNTED BOTH
VERTICALLY AND IN COVERAGE... AS PW REMAINS BELOW NORMAL. THE LATEST
SEVERAL HRRR RUNS SUPPORT THIS AS WELL. WILL KEEP AN ISOLATED SHOWER
CHANCE IN THE WRN AND EXTREME SW CWA THROUGH THE EVENING.
OTHERWISE... FORECAST SOUNDINGS SHOW THE LOW LEVEL MOISTURE
GRADUALLY DISPERSING WITH TIME... STILL GREATER OVER THE WRN CWA
THAN IN THE EAST... SO EXPECT MOSTLY CLEAR SKIES EAST AND PARTLY
CLOUDY WEST. SLOWLY LOWERING SURFACE DEWPOINTS SHOULD LOWER THE RISK
OF FOG... EXCEPT PERHAP IN THE WRN CWA NEAR THE SURFACE TROUGH.
BASED ON LAST NIGHT`S LOWS AND STATISTICAL GUIDANCE... EXPECT LOWS
OF 58-63.
FOR FRI/FRI NIGHT: RAIN CHANCES WILL REMAIN LOW. THE MID LEVEL
TROUGH AXIS IS EXPECTED TO BE SHIFTING TO OUR SE WITH RISING HEIGHTS
ALOFT. LOW LEVEL MOISTURE TRANSPORT PERSISTS BUT IS CONFINED TO THE
FAR SRN AND SE CWA... WHERE PW VALUES WILL HOVER NEAR 1.4-1.5". THE
ONSHORE-DIRECTED LOW LEVEL STEERING FLOW COULD DRAW SHALLOW SEA
BREEZE SHOWERS INLAND OVER THE FAR SE CWA. ISOLATED UPSLOPE-
SUPPORTED SHOWERS REMAIN POSSIBLE IN THE FAR WRN CWA AS WELL. IN
GENERAL HOWEVER... THE TRADITIONAL MODELS REMAIN TOO WET... SHOWING
PRECIP COVERING THE MAJORITY OF THE CWA... WHICH APPEARS UNLIKELY
GIVEN THE LACK OF FORCING AND INSTABILITY WITH LIMITED MOISTURE.
WILL KEEP ISOLATED POPS ALONG THE WRN/SRN AND SE EDGES OF THE CWA
FRI AFTERNOON INTO THE EVENING. THICKNESSES ARE EXPECTED TO DIP
SLIGHTLY... INDICATING HIGHS OF 76-81. LOWS 56-61 WITH PARTLY CLOUDY
SKIES WEST AND MOSTLY CLEAR EAST. -GIH
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 224 PM THURSDAY...
SATURDAY AND SATURDAY NIGHT: HEIGHTS ALOFT WILL CONTINUE TO RISE
OVER THE CAROLINAS ON SATURDAY...AS AN EXTENSION OF THE MID LEVEL
RIDGE CENTERED OVER THE CENTRAL US RIDGE NOSES NORTHEASTWARD INTO
THE AREA...SANDWICHED BETWEEN THE AMPLIFYING NORTHERN STREAM DIVING
SEWD OUT OF SOUTHERN CANADA AND THE REMNANT LOW ALONG THE SOUTHEAST
COAST. AT THE SURFACE...DRY AIR SURFACE RIDGE AXIS WILL WEDGE
SOUTHWESTWARD DOWN THE MID ATLANTIC STATES AND THROUGH THE CAROLINAS
AND GEORGIA. RESULTANT LOW PWATS AND A STABLE AIR COLUMN WILL SECURE
DRY CONDITIONS. HIGHS IN THE UPPER 70S TO LOWER 80S. LOWS SATURDAY
NIGHT UPPER 50S TO LOWER 60S.
SUNDAY: AMPLIFYING/DIGGING NORTHERN STREAM TROUGH AND ASSOCIATED
POLAR WESTERLIES WILL PICK UP THE LINGERING AREA OF LOW PRESSURE
NEAR THE SOUTHEAST COAST AND KICK IT EAST-NORTHEASTWARD...LIFTING UP
THE NC COAST AND THEN OUT INTO THE ATLANTIC ON SUNDAY. LITTLE TO NO
SENSIBLE WEATHER IMPACTS ARE EXPECTED FROM THIS FEATURE...BUT A PRE-
FRONTAL TROUGH IS EXPECTED TO DEVELOP IN THE LEE OF THE MOUNTAINS
SUNDAY AFTERNOON...OWING TO THE APPROACH OF THE NORTHERN STREAM
TROUGH. WOULD NOT BE SURPRISED TO SEE AN ISOLATED SHOWER DEVELOP
INVOF OF THIS TROUGH...BUT WILL KEEP FORECAST DRY. SUNDAY LOOKS TO
BE THE WARMEST DAY IN THE NEXT FORESEEABLE FUTURE WITH LOW-LEVEL
THICKNESSES PROJECTED TO CLIMB 20 METERS ABOVE NORMAL...HIGHS IN THE
LOWER TO MID 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 224 PM THURSDAY...
SUNDAY NIGHT THROUGH MONDAY: 40 TO 60 METER HEIGHT FALLS TRAVERSING
THE REGION IN ADVANCE OF THE AMPLIFYING NORTHER STREAM TROUGH
ADVANCING EASTWARD INTO THE EASTERN US WILL DRIVE A SURFACE COLD
FRONT INTO THE AREA LATE SUNDAY NIGHT/EARLY MONDAY MORNING . WRT THE
COLD FRONTAL PASSAGE ON MONDAY...THE GFS HAS TRENDED TOWARDS THE
FASTER SOLUTION OF THE EC...WHICH HAS THE FRONT SOUTH AND EAST OF
THE AREA BY 18Z MONDAY. GIVEN THE FASTER TIMING...SUFFICIENT
INSTABILITY WILL BE LACKING AND GIVEN LIMITED MOISTURE
AVAILABILITY...CONVECTIVE/RAIN CHANCES REMAIN UNIMPRESSIVE. WILL
LEAVE IN SLIGHT CHANCE POPS...BUT FROPA COULD END BEING A NON-
MEASURABLE/SPRINKLE EVENT FOR MUCH OF THE CWA. FASTER FROPA WILL
RESULT IN SLIGHTLY COOLER TEMPERATURES MONDAY AFTERNOON. HIGHS IN
THE UPPER 70S NW TO LOWER 80S SE.
TUESDAY THROUGH THURSDAY: LIKE CLOCKWORK...A STRONG +1030MB CANADIAN
SURFACE HIGH... ANCHORED UNDERNEATH THE UPPER CONFLUENCE ZONE IN THE
WAKE OF THE EXITING UPPER TROUGH/CLOSED LOW OVER SOUTHERN NEW
ENGLAND...WILL PROVIDE THE FIRST DAYS OF FALL(AUTUMNAL EQUINOX
BEGINS MONDAY SEPT 22 AT 10:29 PM EDT)WITH BONA FIDE FALL
CONDITIONS. DRY WITH TEMPERATURES 5-8 DEGREES BELOW NORMAL. HIGHS 70
TO 75. LOWS IN THE LOWER TO MID 50S...WITH SOME UPPER 40S POSSIBLE
WEDNESDAY NIGHT ACROSS THE NORTHERN PIEDMONT.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 145 PM THURSDAY...
VFR CONDITIONS ARE LIKELY TO HOLD THROUGH THE TAF FORECAST PERIOD.
EARLIER MVFR CIGS AT INT/GSO HAVE MIXED OUT TO SCATTERED... ALTHOUGH
THESE MAY STILL GO BROKEN BRIEFLY PRIOR TO 20Z. OTHERWISE... ANY
CLOUDS THROUGH TONIGHT AND FRI MORNING SHOULD BE BASED ABOVE 3 000
FT AGL... MORE LIKELY TO BE BROKEN AT INT/GSO WITH LESS COVERAGE AT
RDU/RWI/FAY. LIGHT AND VARIABLE WINDS MAINLY FROM THE NE WILL
CONTINUE TONIGHT AT SPEEDS MAINLY UNDER 6 KTS... THEN SHOULD
INCREASE TO 7-10 KTS FROM THE ENE AFTER 14Z FRI.
LOOKING BEYOND 18Z FRI... VFR CONDITIONS SHOULD DOMINATE THROUGH AT
LEAST SUNDAY... ALTHOUGH MVFR FOG IS POSSIBLE EARLY SAT MORNING AS
THE LIGHT ONSHORE LOW LEVEL FLOW PERSISTS. A PERIOD OF MVFR CIGS IS
POSSIBLE LATE SUN INTO SUN NIGHT AHEAD OF A COLD FRONT. VFR
CONDITIONS SHOULD THEN RETURN FOR MON/TUE WITH HIGH PRESSURE
BUILDING IN FROM THE NW. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 PM EDT THU SEP 18 2014
.SYNOPSIS...HIGH PRESSURE CENTERED NORTHEAST OF THE GREAT LAKES WILL
EXTEND DOWN THROUGH VIRGINIA AND THE CAROLINAS THROUGH THE
WEEKEND... AS IT SLIDES EAST. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST LATE SUNDAY... THEN MOVE SOUTHEAST THROUGH THE REGION
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 220 PM THURSDAY...
THROUGH TONIGHT: QUIET AND DRY NIGHT FOR MOST. SURFACE MAP SHOWS A
WEAK MSLP PATTERN OVER NC WITH A WEAK INVERTED TROUGH OVER THE WRN
PIEDMONT... HELPING TO FOCUS MOISTURE IN THE LOWEST 5-6 THOUSAND FT
IN THIS AREA AND FOSTERING DEVELOPMENT OF VERY ISOLATED SHALLOW
SHOWERS. THESE SHOULD PERSIST INTO THE EVENING HOURS... GIVEN THIS
WEAK LOW LEVEL MASS CONVERGENCE IN CONJUNCTION WITH WEAK TERRAIN
UPGLIDE... BUT WITH A CAPPING INVERSION EVIDENT AT 775-750 MB AND
WARM/DRY/STABLE AIR ABOVE... EXPECT DEVELOPMENT TO BE STUNTED BOTH
VERTICALLY AND IN COVERAGE... AS PW REMAINS BELOW NORMAL. THE LATEST
SEVERAL HRRR RUNS SUPPORT THIS AS WELL. WILL KEEP AN ISOLATED SHOWER
CHANCE IN THE WRN AND EXTREME SW CWA THROUGH THE EVENING.
OTHERWISE... FORECAST SOUNDINGS SHOW THE LOW LEVEL MOISTURE
GRADUALLY DISPERSING WITH TIME... STILL GREATER OVER THE WRN CWA
THAN IN THE EAST... SO EXPECT MOSTLY CLEAR SKIES EAST AND PARTLY
CLOUDY WEST. SLOWLY LOWERING SURFACE DEWPOINTS SHOULD LOWER THE RISK
OF FOG... EXCEPT PERHAP IN THE WRN CWA NEAR THE SURFACE TROUGH.
BASED ON LAST NIGHT`S LOWS AND STATISTICAL GUIDANCE... EXPECT LOWS
OF 58-63.
FOR FRI/FRI NIGHT: RAIN CHANCES WILL REMAIN LOW. THE MID LEVEL
TROUGH AXIS IS EXPECTED TO BE SHIFTING TO OUR SE WITH RISING HEIGHTS
ALOFT. LOW LEVEL MOISTURE TRANSPORT PERSISTS BUT IS CONFINED TO THE
FAR SRN AND SE CWA... WHERE PW VALUES WILL HOVER NEAR 1.4-1.5". THE
ONSHORE-DIRECTED LOW LEVEL STEERING FLOW COULD DRAW SHALLOW SEA
BREEZE SHOWERS INLAND OVER THE FAR SE CWA. ISOLATED UPSLOPE-
SUPPORTED SHOWERS REMAIN POSSIBLE IN THE FAR WRN CWA AS WELL. IN
GENERAL HOWEVER... THE TRADITIONAL MODELS REMAIN TOO WET... SHOWING
PRECIP COVERING THE MAJORITY OF THE CWA... WHICH APPEARS UNLIKELY
GIVEN THE LACK OF FORCING AND INSTABILITY WITH LIMITED MOISTURE.
WILL KEEP ISOLATED POPS ALONG THE WRN/SRN AND SE EDGES OF THE CWA
FRI AFTERNOON INTO THE EVENING. THICKNESSES ARE EXPECTED TO DIP
SLIGHTLY... INDICATING HIGHS OF 76-81. LOWS 56-61 WITH PARTLY CLOUDY
SKIES WEST AND MOSTLY CLEAR EAST. -GIH
&&
.SHORT TERM / /...
AS OF 310 AM THURSDAY...
TO BE UPDATED.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
A PORTION OF THE LONGWAVE TROUGH INITIALLY ALONG THE EAST COAST WILL
BE LEFT BEHIND AND SUPPORT WEAK FRONTAL WAVE DEVELOPMENT OFFSHORE
THE SE US COAST THIS WEEKEND...BUT THE OTHERWISE DEAMPLIFYING/LIFTING
TROUGH WILL YIELD TO RISING HEIGHTS ALOFT OVER THE CAROLINAS...AS A
FLAT MID LEVEL RIDGE RIDGE NOSES EASTWARD FROM THE SOUTHERN PLAINS
AND LOWER MS VALLEY. THE RE-ESTABLISHMENT AND AMPLIFICATION OF A
WESTERN NOAM RIDGE WILL THEN RESULT IN DOWNSTREAM TROUGH
AMPLIFICATION FROM SOUTH-CENTRAL CANADA TO THE EAST-CENTRAL US THIS
WEEKEND-EARLY NEXT WEEK. THE WESTERN RIDGE...IN PROGRESSIVE FLOW
ALOFT...WILL BUILD EAST ACROSS THE MID-LATITUDES OF THE CENTRAL AND
EASTERN STATES MID TO LATE NEXT WEEK.
BENEATH THE CONTINUED RISING HEIGHTS ALOFT SAT...A CANADIAN SFC HIGH
(AROUND 1030 MB) WILL BUILD FROM CENTRAL CANADA TO THE CANADIAN
MARITIMES AND RIDGE SOUTH/SOUTHWESTWARD THROUGH THE EASTERN STATES
THROUGH THE FIRST HALF OF THE WEEKEND...BEFORE YIELDING - AMIDST
FALLING HEIGHTS DOWNSTREAM OF THE AFOREMENTIONED REDEVELOPING TROUGH
ALOFT HEADED FOR THE EAST-CENTRAL US - TO APPALACHIAN-LEE SFC TROUGH
DEVELOPMENT SUN...AND A PASSING COLD FRONT MON. ANOTHER STRONG
CANADIAN HIGH WILL EXPAND AND STRENGTHEN ACROSS MUCH OF THE CENTRAL
AND EASTERN CONUS IN THE WAKE OF THE PASSING COLD FRONT...WHICH
GUIDANCE SUGGESTS WILL CLEAR ALL BUT PERHAPS SOUTHERN FL BY MID NEXT
WEEK.
WITH THE BRUNT OF THE COOLER AND DRIER AIR ASSOCIATED WITH THE LEAD
HIGH LIKELY TO HOLD OVER THE NORTHERN MIDDLE ATLANTIC AND NORTHEAST
STATES THIS WEEKEND...CENTRAL NC TEMPERATURES ARE APT TO WARM TO ABOVE
AVG...IN THE LOWER TO MIDDLE 80S - WARMEST SUNDAY. ANY SIGNIFICANT
LOW-MID LEVEL CLOUD COVER ATTENDING THE OFFSHORE FRONTAL WAVE IS
FORECAST AT THIS TIME TO HOLD ALONG COASTAL AREAS...WITH MORE OF A
NORTHWESTERLY FLOW COMPONENT OVER CENTRAL NC...INTO THE OFFSHORE
LOW/FRONTAL ZONE.
FRONTAL PASSAGE TIMING HAS SPED FOR MON...SUCH THAT A FEW LINGERING
SHOWERS FROM UPSTREAM CONVECTION MAY DRIFT INTO THE NW PIEDMONT SUN
NIGHT...AND LEAVE MAINLY THE FAR SOUTHEAST CWFA IN THE WARM SECTOR
THROUGH EARLY AFTERNOON...WITH EARLIER/UNFAVORABLE DIURNAL FRONTAL
TIMING ACROSS THE REMAINDER OF THE AREA. SHOWER CHANCES WILL BE
RELATIVELY LOW...THROUGHOUT THIS PERIOD...HOWEVER...AS GULF MOISTURE
RETURN WILL BE LIMITED. COOLER TUE-WED...WITH HIGHS IN THE 70S IN
THE POST-FRONTAL CANADIAN HIGH...WITH SFC DEWPOINTS IN THE 40S-50S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 145 PM THURSDAY...
VFR CONDITIONS ARE LIKELY TO HOLD THROUGH THE TAF FORECAST PERIOD.
EARLIER MVFR CIGS AT INT/GSO HAVE MIXED OUT TO SCATTERED... ALTHOUGH
THESE MAY STILL GO BROKEN BRIEFLY PRIOR TO 20Z. OTHERWISE... ANY
CLOUDS THROUGH TONIGHT AND FRI MORNING SHOULD BE BASED ABOVE 3 000
FT AGL... MORE LIKELY TO BE BROKEN AT INT/GSO WITH LESS COVERAGE AT
RDU/RWI/FAY. LIGHT AND VARIABLE WINDS MAINLY FROM THE NE WILL
CONTINUE TONIGHT AT SPEEDS MAINLY UNDER 6 KTS... THEN SHOULD
INCREASE TO 7-10 KTS FROM THE ENE AFTER 14Z FRI.
LOOKING BEYOND 18Z FRI... VFR CONDITIONS SHOULD DOMINATE THROUGH AT
LEAST SUNDAY... ALTHOUGH MVFR FOG IS POSSIBLE EARLY SAT MORNING AS
THE LIGHT ONSHORE LOW LEVEL FLOW PERSISTS. A PERIOD OF MVFR CIGS IS
POSSIBLE LATE SUN INTO SUN NIGHT AHEAD OF A COLD FRONT. VFR
CONDITIONS SHOULD THEN RETURN FOR MON/TUE WITH HIGH PRESSURE
BUILDING IN FROM THE NW. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...MWS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
326 PM CDT THU SEP 18 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 326 PM CDT THU SEP 18 2014
CONVECTIVE FORECAST CONTINUES TO BE COMPLICATED BY A RELATIVELY
STRONG LOW LEVEL CAPPING INVERSION ACROSS CENTRAL AND EASTERN
NORTH DAKOTA BUT WITH MID AND HIGH CAPE ABOVE AS MOST FLOW
OVERRIDES. WARM FRONT CURRENTLY EXTENDS FROM LOW PRESSURE IN
SOUTH CENTRAL SASKATCHEWAN SOUTHEAST THROUGH WESTERN NORTH DAKOTA.
WARM ADVECTION OVER THE WARM FRONT CURRENTLY GENERATING SOME
ELEVATED CONVECTION ACROSS NORTH CENTRAL NORTH DAKOTA AS CURRENT
NAM MODEL FAIRLY WELL PREDICTS. LATEST HRRR DOES NOT HANDLE THIS
WELL. CURRENT THINKING HAS THE MAJORITY OF CONVECTION WITH THE
COLD FRONT LATER TONIGHT. POPS FOR TONIGHT ARE STILL A BIT SPOTTY
OWING TO THE CAP...MOSTLY 20 TO 30 POPS. BY FRIDAY NORTHWEST FLOW
BEHIND THE COLD FRONT WILL SUPPRESS THUNDERSTORMS SOUTH AND
FOCUSED ON THE NORTH HALF FRIDAY AFTERNOON. LOWS TONIGHT 55 TO 65
AND HIGHS FRIDAY 78 TO 86.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 326 PM CDT THU SEP 18 2014
FRIDAY NIGHT THROUGH SATURDAY THE FORECAST AREA WILL BE UNDER THE
INFLUENCE OF NORTHWEST FLOW ALOFT WITH WEAK SHORT WAVES EMBEDDED IN
THE FLOW. THUS WILL KEEP THE SMALL CHANCE MENTION OF THUNDERSTORMS
MAINLY OVER NORTHERN COUNTIES.
THEN THE UPPER LEVEL WESTERN RIDGE PUSHES EASTWARD...ALONG WITH
SURFACE HIGH PRESSURE...BRINGING DRY CONDITIONS TO WESTERN AND
CENTRAL NORTH DAKOTA THROUGH MONDAY.
ALONG WITH THE WESTERN RIDGE...AN UPPER LEVEL LOW OVER CALIFORNIA
SATURDAY WILL MEANDER SLOWLY BENEATH THE RIDGE CREATING A REX BLOCK
OVER THE ROCKIES. BY EARLY NEXT WEEK THE WESTERN RIDGE BEGINS TO
PROGRESS EASTWARD AND THE MEANDERING UPPER LOW IS FORECAST TO MOVE
INTO THE PLAINS. MODELS ARE COMING INTO BETTER AGREEMENT AND LIFTING
THE UPPER LOW NORTHEASTWARD - APPROACHING NORTH DAKOTA ON TUESDAY.
THIS SLOW-MOVING LOW WILL BRING SOME CHANCE OF SHOWERS/THUNDER TO
THE REGION TUESDAY THROUGH THURSDAY...BUT CONFIDENCE IS NOT HIGH
REGARDING ITS IMPLICATIONS FOR PLACEMENT/TIMING OF PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 326 PM CDT THU SEP 18 2014
LOW PRESSURE IN SOUTH CENTRAL SASKATCHEWAN WITH AN ASSOCIATED WARM
FRONT WILL MOVE EAST TONIGHT. THIS WILL BE FOLLOWED BY A COLD FRONT
LATE TONIGHT AND FRIDAY. SCATTERED TO WIDELY SCATTERED THUNDERSTORMS
WILL BE ASSOCIATED WITH THE WARM FRONT ACROSS CENTRAL NORTH DAKOTA
THIS EVENING. THE COLD FRONT WILL BE THE FOCUS FOR THUNDERSTORMS
ACROSS WEST AND CENTRAL TONIGHT...AND ACROSS NORTHERN NORTH DAKOTA
FRIDAY. USED VCTS TO DESCRIBE THE THUNDERSTORM THREAT EARLY ON BUT
OVERALL TO UNCERTAIN TO INCLUDE TSRA IN TAFS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
LONG TERM...JV
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1255 PM CDT THU SEP 18 2014
.UPDATE...
ISSUED AT 1249 PM CDT THU SEP 18 2014
AFTERNOON FORECAST ON TRACK AS JUST A FINGER OF STRATUS LEFT ON
VISIBLE SATELLITE IMAGERY IMPACTING THE ND SIDE OF THE RRV. TEMPS
WARMING RAPIDLY WITH SUN...UP 10 DEGREES AT CROOKSTON IN THE PAST
90 MIN. STILL SEE NO REASON FOR ADJUSTING MAX TEMPS SO WILL LEAVE
THEM IN THE 70S VALLEY AND WEST WITH UPPER 60S IN THE MN PINES.
UPDATE ISSUED AT 936 AM CDT THU SEP 18 2014
CHALLENGES FOR THIS MORNINGS UPDATE INCLUDES LOW STRATUS AND
DISSIPATING FOG. STRATUS DECK ALONG AND EAST OF THE RRV WILL
ERODE AS PRESSURE GRADIENT INCREASES BETWEEN DEPARTING GREAT
LAKES SFC HIGH AND DEVELOPING TROUGH OF LOW PRESSURE IN THE HIGH
PLAINS. THIS MIXING WILL QUICKLY ERODE THE STRATUS IN THE NEXT
COUPLE OF HOURS. THE RAP AND HRRR INDICATE THIS IN THEIR LATEST
SOLNS. ADJUSTED THE SKY GRIDS AND TEMP CURVE THROUGH EARLY
AFTERNOON AND KEPT THE INHERITED MAX TEMPS THE SAME.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
THE MAIN CHALLENGE WILL BE CONVECTIVE CHANCES LATER TODAY THROUGH
SATURDAY. MODELS REMAIN IN VERY GOOD OVERALL AGREEMENT...WITH A
FEW MINOR DIFFERENCES.
FOR TODAY...THERE WILL BE A BAND OF CLOUDS AT LEAST THIS MORNING
AFFECTING AREAS ALONG AND EAST OF THE VALLEY. THERE IS ALSO SOME
PATCHY FOG WITH THIS STRATUS...AND WILL ADD SOME FOR EARLY
MORNING. THIS STRATUS COULD HOLD TEMPS DOWN ONCE AGAIN IF THEY DO NOT
ERODE UNTIL MID/LATE AFTERNOON...SO TEMP FORECAST WILL BE TRICKY
FOR SOME AREAS WHERE CLOUDS HOLD. IT SHOULD REMAIN DRY THROUGH 00Z
FRI...WITH SOUTHEAST WINDS INCREASING THIS AFTERNOON.
FOR TONIGHT...THE CHANCES FOR SHOWERS AND STORMS SHOULD DEVELOP
FROM WEST TO EAST THROUGH THE NIGHT. IT COULD BE WINDY FOR MUCH OF
THE NIGHT WITH GOOD MIXING AT LEAST THIS EVENING...AND 30-40KT TO
MIX. A DEVELOPING INVERSION SHOULD KEEP STRONGER WINDS FROM MIXING
DOWN THOUGH. A STRONG CAP WILL BE IN PLACE MUCH OF THE NIGHT...BUT
THE CAP NEAR 850MB SHOULD ERODE LATE WITH THE BEST FORCING AND MID
LEVEL MOISTURE ADVECTION IN THE NORTH.
ON FRIDAY...THERE COULD BE A FEW BANDS OF SHOWERS AND STORMS...ONE
IN THE MORNING IN THE EAST...AND ANOTHER LATER IN THE AFTERNOON IN
THE WEST. GIVEN THESE TOUGH TO TIME WAVES...WE WILL CONTINUE WITH
MAINLY LOW END CHANCE POPS FOR SHOWERS AND STORMS. IT SHOULD BE
WARM WITH WESTERLY SFC WINDS AND AT LEAST SOME SUNSHINE...WITH
AROUND 80 IN THE WEST AND LOW 70S EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
FOR FRI NIGHT...EXPECT CONTINUED CHANCES FOR SOME CONVECTION...AS
AS A SFC BOUNDARY MOVES THROUGH THE AREA. THE BEST CHANCE FOR
MEASURABLE RAIN WILL OCCUR IN THE NORTHERN AREAS CLOSER TO SFC LOW TRACK.
ON SATURDAY...A STRONG SPEED MAX WILL ENHANCE LARGE SCALE
DIVERGENCE ALOFT. THIS COUPLED WITH PWATS STILL NEAR 1 INCH IN THE
NORTH...AND SOME LINGERING INSTABILITY SHOULD MEAN MAINLY SHOWER
CHANCES AND PERHAPS A RUMBLE OF THUNDER. THE BEST CHANCE FOR
PRECIP COULD OCCUR LATE IN THE MORNING/EARLY AFTERNOON AS
SHORTWAVE MOVES THROUGH. COOL ADVECTION WILL MOVE IN SAT AFTERNOON
WITH NW WINDS INCREASING TO AT LEAST 20KT IN THE NW...ALONG WITH
ADIABATIC SOUNDINGS UP TO AROUND 700MB WITH 35KT TO MIX. TEMPS
WILL BE COOL TO AROUND NORMAL...WITH MORE CLOUDS AND CAA BY
AFTERNOON.
FOR SAT NIGHT...IT SHOULD BE MAINLY DRY WITH PERHAPS A LINGERING
SHOWER MAINLY IN THE NORTHEAST.
LONG WAVE RIDGE AXIS REMAINS OVER WESTERN CANADA THROUGH MUCH OF THE
PERIOD. BY DAY 7 ZONAL FLOW IS ACROSS CANADA. THE GFS IS FASTER THAN
THE ECMWF. WILL PREFER THE SLOWER ECMWF.
UPPER LOW OFF THE WEST COAST IS FORECAST TO MOVE INTO THE PLAINS BY
WED. WILL ADD POPS FOR WED.
TEMPS WERE DECREASED BY A DEGREE FOR SUN AND INCREASED A DEGREE FOR
MON...TUE AND WED COMPARED TO YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1249 PM CDT THU SEP 18 2014
IFR CLD COVER RAPIDLY ERODING WITH VFR CONDITIONS ARRIVING AT VALLEY
AIRFIELDS. GRADIENT WIND FROM SOUTH STARTING TO INCREASE
NOW...EXPECT 15 TO 20 KTS G25 EVERYWHERE BY MID AFTERNOON. RW/TRW TO
APPROACH OVERNIGHT INTO THUR...SUFFICIENTLY LOW POP WARRANTS
OMISSION FROM TAFS AT THIS TIME.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JK
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...WJB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
700 PM EDT THU SEP 18 2014
.SYNOPSIS...
HIGH PRESSURE THROUGH SATURDAY. COLD FRONT SUNDAY. HIGH PRESSURE
NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
LOWER DEW POINTS HAVE FILTERED INTO SOUTHEAST OHIO AND NORTHERN WEST
VIRGINIA LATE THURSDAY AFTERNOON. WILL LOWER MINIMUM TEMPERATURE
THERE A FEW DEGREES.
AT 2245Z...VAD WINDS AT 925 MB STILL FM THE NNE. RAP MODEL QUICKLY
VEERS THE 925 MB FLOW TO EAST BY 06Z. THUS CLOUDS SHOULD INCREASE
ALONG THE EASTERN SLOPES OVERNIGHT. WILL FAVOR CLOUDS OVER FOG FOR
THE UPPER GREENBRIER VALLEY IN POCAHONTAS COUNTY.
DEW POINTS THE HIGHEST CRW ON SOUTH NEAR SUNSET. THINKING THAT AREA
HAS THE BEST CHANCE FOR DIURNAL FOG...FORMING FIRST OVER THE
HEADWATERS OF THE TUG FORK AND GUYANDOTTE RIVER VALLEYS.
NO CHANGES TO POPS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A HIGH PRESSURE SYSTEM CONTINUES OVER THE AREA FOR FRIDAY NIGHT AND
SATURDAY. NAM IS SHOWING SOME MOISTURE IN THE MOUNTAINS SATURDAY
AFTERNOON...POSSIBLY ALLOWING FOR A COUPLE OF SHOWERS.
A COLD FRONT THEN MOVES THROUGH ON SUNDAY. THE ECMWF AND GFS ARE THE
FASTEST WITH THIS SYSTEM...WITH THE NAM THE SLOWEST...AND THE SREF
AND CANADIAN IN BETWEEN. UPPER AIR SUPPORT WOULD LEND TOWARD A
SLOWER SOLUTION...BUT WITHOUT A LOT OF MODEL SUPPORT...WILL STAY
TOWARD THE MIDDLE GROUND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
USED WPC THINKING WITH SOME MINOR TWEAKS. COLD FRONT WILL PUSH
SOUTHEAST OF THE MOUNTAINS SUNDAY NIGHT WITH HIGH PRESSURE TAKING
CONTROL BY MONDAY AFTERNOON. THE HIGH SHOULD BE IN CONTROL THROUGH
THE REMAINDER OF THE PERIOD...RESULTING IN DRY AND SEASONABLY COOL
TEMPERATURES.
WPC TEMPS LOOKED GOOD AND WERE GENERALLY USED.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AT 2245Z...VAD WINDS AT 925 MB LEVEL STILL FM THE NNE. RAP MODEL
QUICKLY VEERS THE 925 MB FLOW TO EAST BY 06Z. THUS CLOUDS SHOULD
INCREASE ALONG THE EASTERN SLOPES IN THE 06Z TO 12Z FRIDAY TIME
FRAME. TIMING THE LOWER CEILINGS INTO BKW TRICKY...BUT HELD OFF
UNTIL AFTER 06Z. WILL TRY TO KEEP CEILINGS MOSTLY 1 TO 2 THSD FT
AND MVFR. SOME IFR CEILINGS POSSIBLE THOUGH OVER THE HIGHER RIDGES.
WILL FAVOR CLOUDS OVER FOG FOR THE UPPER GREENBRIER VALLEY IN
POCAHONTAS COUNTY. BUT FURTHER WEST...FAVORED FOG OVER CLOUDS FOR
ELKINS VCNTY.
DEW POINTS THE HIGHEST CRW ON SOUTH NEAR SUNSET. THINKING THAT AREA
HAS THE BEST CHANCE FOR IFR/LIFR DIURNAL FOG...FORMING FIRST OVER
THE HEADWATERS OF THE TUG FORK AND GUYANDOTTE RIVER
VALLEYS...FORECASTING IFR IN FOG REACHING CRW 06Z TO 08Z.
IN THE DRIER AIR FURTHER WEST AND NORTHWEST...SOME RIVER VALLEY FOG
OVER THE OHIO RIVER MAY FORM FOR 09Z TO 12Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING LOWERING CEILING INTO SRN WV MOUNTAINS
WITH THE DEVELOPING EASTERLY UPSLOPE FLOW AROUND BKW MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H M M L L
HTS CONSISTENCY H H H H H H H H H H M M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H M L L L M
PKB CONSISTENCY H H H H H H H H H M L L
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 00Z SATURDAY...
BRIEF IFR CONDITIONS POSSIBLE SUNDAY IN SHOWERS/STORMS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...50/26
NEAR TERM...KTB
SHORT TERM...RPY
LONG TERM...JSH
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS PENDLETON OR
1028 AM PDT THU SEP 18 2014
UPDATED AVIATION DISCUSSION
.UPDATE...THE CURRENT FORECAST REMAINS ON TRACK WITH JUST A FEW
MINOR ADJUSTMENTS TO THE TODAY AND THIS EVENING PERIOD. HAVE MADE
SOME MINOR ADJUSTMENTS TO THE HIGHS TODAY...MAINLY ACROSS THE
WESTERN PORTION OF THE CWA.
EXPECT WINDY CONDITIONS ALONG THE KITTITAS VALLEY AND THE COLUMBIA
RIVER GORGE TODAY...WITH THE BASIN AND FOOTHILL AREAS BEING BREEZY.
EXPECT 20 MPH GUSTING TO 30 MPH FOR THE GORGE AND THE KITTIAS
VALLEY...WITH 15 MPH GUSTING 25 MPH ELSEWHERE ACROSS THE BASIN.
WINDS SHOULD BEGIN TO PICK UP AFTER NOON TODAY...AND ARE EXPECTED TO
BE STRONGEST AROUND 5 PM DIMINISHING AFTER MIDNIGHT.
HAVE ALSO PULLED BACK ON POPS TO GO MOSTLY SLIGHT CHANCE EAST OF THE
CASCADE CREST. THE SPLIT FLOW WILL CUT OFF MOST OF THE MOISTURE
FROM THE TROUGH THAT WILL PROGRESS SOUTH ALONG THE CALIFORNIA COAST
TODAY INTO TONIGHT. SLIGHT CHANCE UPSLOPE SHOWERS CAN BE EXPECTED
ACROSS THE NORTHEAST MOUNTAINS TODAY AND THIS EVENING. HAVE
MENTIONED SLIGHT CHANCE THUNDER ACROSS THE NORTHEAST MOUNTAINS
THROUGH 5 PM...AS IT STILL CAN`T BE RULED OUT. BUT ONCE THE WEST
NORTHWEST FLOW SETS IN THIS EVENING...INSTABILITY WILL BE VERY
LIMITED. SO HAVE PULLED BACK ON THE THUNDER POTENTIAL TO JUST THE
EAGLE CAPS...SOUTHERN GRANT...CROOK...AND DESCHUTES COUNTY FROM 5 TO
8 PM THIS EVENING. WEBER
.AVIATION...18Z TAFS...VFR CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NEXT 24 HOURS. THERE MAY BE SOME LIGHT SHOWERS AROUND
THE REGION TODAY WITH THE REMOTE POSSIBILITY OF A THUNDERSTORM AT
KRDM AND KBDN IN THE AFTERNOON AND EVENING...THEN PARTIAL CLEARING
OVERNIGHT. WESTERLY WINDS WILL BE INCREASE SLIGHTLY TODAY AT 10 TO
20 MPH THEN DECREASE OVERNIGHT.
&&
.PREV DISC... /ISSUED 255 AM PDT THU SEP 18 2014/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...AN UPPER LEVEL TROUGH
IS NEAR THE COAST AS IT SLOWLY SHIFTS EASTWARD. THE TROUGH IS
SPLITTING AS IT MOVES INLAND WITH THE NORTHERN SECTION IN WASHINGTON
AND THE SOUTHERN SECTION IN CALIFORNIA. THERE ARE TWO BANDS OF
PRECIPITATION ON RADAR AND MODELS. ONE IS NEAR THE CASCADES ON THE
EAST SIDE OF THE TROUGH AXIS AND THE SECOND ONE IS IN EASTERN GRANT
COUNTY...WALLOWA COUNTY...AND BAKER COUNTY. HRRR SHOWS THE FIRST
BAND REMAINING IN CENTRAL/NORTH CENTRAL OREGON AND CENTRAL
WASHINGTON THIS MORNING. THE SECOND BAND IS ASSOCIATED WITH A JET
STREAK. HRRR SHOWS THIS BAND REMAINING SEPARATE AND MOVING NORTHEAST
OUT OF THE OREGON BY 16Z. THE MORNING FORECAST HAS THE TWO SEPARATE
BANDS...THEN THE FIRST BAND WILL SPREAD ACROSS CENTRAL TO NORTHEAST
OREGON AS THE TROUGH AXIS MOVES ACROSS EASTERN WASHINGTON AND OREGON
THIS AFTERNOON. THE BEST INSTABILITY WILL MOVE FROM CENTRAL TO
NORTHEAST OREGON WHERE THE DIFFLUENCE FROM THE SPLITTING TROUGH IS
ADDED TO THE INSTABILITY AHEAD OF THE TROUGH. ISOLATED THUNDERSTORMS
MAY DEVELOP IN THIS REGION DURING THE AFTERNOON AND EARLY EVENING.
THE TROUGH AXIS WILL BE IN IDAHO BY 6Z/2300 PDT WITH RAIN SHOWERS
ENDING EXCEPT FOR OROGRAPHIC SHOWERS NEAR THE CASCADE CREST. FRIDAY
AND SATURDAY THE UPPER LEVEL RIDGE WILL BUILD OVER THE PACIFIC
NORTHWEST WITH CLEARING SKIES AND WARMING DAYTIME TEMPERATURES.
COONFIELD
LONG TERM...SUNDAY THROUGH WEDNESDAY...00Z MODEL RUNS INDICATE VERY
SIMILAR SOLUTIONS OVER FORECAST AREA AND NORTHEAST PACIFIC WITH A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUING OVER THE PACIFIC
NORTHWEST SUNDAY AND MONDAY. MODELS SHOW CONSISTENT SOLUTIONS FOR
TUESDAY AS WELL WITH THE RIDGE MOVING EAST INTO THE NORTHERN PLAINS
BY DAYBREAK TUESDAY AS THE NEXT LONGWAVE TROUGH SPREADS EASTWARD TO
130-140W. THE GFS IS MORE PROGRESSIVE IN TAKING THE AXIS OF AN OPEN
LONGWAVE TROUGH TO 132W BY TUESDAY AFTERNOON WHEREAS THE ECMWF KEEPS
THE LOWEST HEIGHTS IN THE OVERALL TROUGH NEAR 140W WHERE A CLOSED
LOW WITH MUCH LOWER HEIGHTS DEVELOPS IN THE ECMWF SOLUTION. BOTH GFS
AND ECMWF SHOW A VERY WEAK DISTURBANCE MOVING THROUGH FORECAST AREA
MONDAY NIGHT AND TUESDAY SO I HAVE INCREASED POPS A TAD TO SLIGHT
CHANCE FOR POSSIBLE ISOLATED LIGHT SHOWERS IN THE BLUE MOUNTAINS
MONDAY NIGHT AND TUESDAY. THE TROUGH APPROACHES THE COAST TUESDAY
NIGHT AND SPREADS INCREASING CLOUDS, MOISTURE, AND RAIN TO THE
CASCADES JUST BEFORE DAYBREAK ON WEDNESDAY. THE PRECIPITATION
SPREADS ACROSS FORECAST AREA WEDNESDAY MORNING. AS ALREADY
MENTIONED, THE GFS IS FASTER IN TERMS OF BRINGING THE TROUGH AXIS TO
THE COAST BY LATE WEDNESDAY MORNING WHILE THE ECMWF KEEPS THE TROUGH
AXIS WELL OFFSHORE. THIS PHASING DIFFERENCE BETWEEN THE TWO MODELS
ON WEDNESDAY WITH RESPECT TO THE PLACEMENT OF THE TROUGH AXIS
RESULTS IN THE ECMWF TAKING LONGER TO SPREAD RAIN TO THE BLUE
MOUNTAINS UNTIL LATE WEDNESDAY NIGHT OR THURSDAY MORNING. AS SUCH
HAVE LOWER CONFIDENCE IN POP FORECAST FOR WEDNESDAY IN THE EASTERN
SECTIONS OF FORECAST AREA. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 80 55 80 52 / 20 10 0 0
ALW 83 61 80 57 / 20 10 0 0
PSC 85 57 85 51 / 10 10 0 0
YKM 80 56 84 54 / 20 10 0 0
HRI 83 55 85 48 / 10 10 0 0
ELN 80 57 83 52 / 20 10 0 0
RDM 76 43 79 40 / 20 20 0 0
LGD 81 51 79 44 / 20 10 0 0
GCD 78 49 81 47 / 20 10 0 0
DLS 78 58 83 52 / 30 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
89/99/99
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1250 PM CDT THU SEP 18 2014
.AVIATION...
TROPICAL MOISTURE PROFILE ACROSS THE AREA NEXT 24 HOURS WITH THE
REMAINS OF TS ODILE EXPECTED TO MOVE SLOWLY FROM SOUTHWEST TO
CENTRAL NEW MEXICO. IN ADDITION TO DEEP MOISTURE...THIS WILL FAVOR
DEEP LIFT AND PREVAILING RAIN AND THUNDER CHANCES FOR KLBB.
AIRMASS JUST WEST AND SOUTHWEST OF KLBB APPEARS TO BE QUICKLY
DESTABILIZING AGAIN EARLY THIS AFTERNOON AND SHOULD SUPPORT
INCREASING THUNDER CHANCES. A WESTWARD MOVING CONVECTIVE OUTFLOW
NOW IN WESTERN OKLAHOMA WILL MOVE THROUGH KCDS BY 20Z AND APPROACH
KLBB 22Z-00Z TIME FRAME WHICH ALSO SHOULD HELP ENHANCE THUNDER
CHANCES. DO NOT ANTICIPATE NECESSARILY CONTINUOUS PRECIPITATION
CHANCES AT KLBB BUT THE BREAKS ARE DIFFICULT TO SUPPORT OR TIME.
MORE STRATIFORM ENVIRONMENT SEEMS MORE LIKELY OVERNIGHT WITH LOW
CEILING AND VISIBILITY RISK KLBB ESPECIALLY AND MOSTLY IFR
POSSIBLY LIFR CONDITIONS. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 1005 AM CDT THU SEP 18 2014/
UPDATE...
THE FLOOD WATCH HAS BEEN EXPANDED EASTWARD TO INCLUDE MOST OF THE
CWA...EXCLUDING HALL AND CHILDRESS COUNTIES. A LARGE AREA OF
MODERATE RAINFALL CONTINUES TO ENVELOP MUCH OF THE FA...WITH
POCKETS OF HEAVY RAIN. IT APPEARS THE HEAVIEST OF THE RAINFALL IS
GOING TO TEND TO CONVERGE ACROSS OUR SOUTHEAST ZONES OVER THE NEXT
COUPLE OF HOURS...AND FOR THIS REASON WE HAVE DECIDED TO EXPAND
THE FLOOD WATCH EASTWARD. POP...WEATHER AND QPF GRIDS WERE ALSO
ADJUSTED GIVEN CURRENT RADAR TRENDS AND HIGH RESOLUTION MODELS. A
MENTION OF HEAVY RAIN WAS ALSO ADDED TO A GOOD CHUNK OF THE AREA
THIS MORNING...WHILE MAINTAINING THE HEAVY RAIN MENTION ACROSS THE
SOUTHEAST ZONES THIS AFTERNOON. UPDATED PRODUCTS HAVE BEEN SENT.
PREV DISCUSSION... /ISSUED 630 AM CDT THU SEP 18 2014/
AVIATION...
FLYING WEATHER FOR VFR PILOTS WILL BE A DISAPPOINTMENT NEXT 24
HOURS. WIDESPREAD RAINFALL WITH EMBEDDED TSTMS WILL LIKELY PERSIST
MUCH OF THE FCST PERIOD. WE MAY SEE SOME PERIOD OF MVFR/VFR AT
KLBB BUT THIS IS LIKELY ONLY TO EXIST BETWEEN STORMS AS WIDESPREAD
RAINFALL IS EXPECTED THIS MORNING WITH PERHAPS AN AFTERNOON BREAK
THEN MORE AGAIN TONIGHT. IFR AIRCRAFT SHOULD BE IMPACTED MUCH LESS
HEAVILY THOUGH MANEUVERING AROUND CONVECTIVE CELLS WILL BE
NECESSARY.
PREV DISCUSSION... /ISSUED 322 AM CDT THU SEP 18 2014/
SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING WEST TO EAST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE
DISTURBANCE PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE
SFC WILL VEER TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD
FRONTAL PASSAGE /WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/.
THIS COLD FRONT WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH
SUNDAY...WITH A NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 63 74 61 82 59 / 60 70 60 30 30
TULIA 64 77 63 80 62 / 50 70 60 50 30
PLAINVIEW 64 77 63 80 62 / 60 70 60 50 30
LEVELLAND 65 76 63 81 63 / 70 70 60 40 40
LUBBOCK 67 77 66 81 65 / 70 70 60 50 40
DENVER CITY 66 78 64 84 63 / 70 70 60 40 40
BROWNFIELD 67 78 64 83 64 / 70 70 60 40 40
CHILDRESS 67 83 67 80 66 / 50 50 60 60 40
SPUR 67 80 65 82 66 / 60 50 60 50 50
ASPERMONT 69 85 69 85 68 / 60 50 60 50 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>044.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1239 PM CDT THU SEP 18 2014
.DISCUSSION...
SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...
AVIATION CONDITIONS WILL BRIEFLY IMPROVE AT KIAH AND KHOU THROUGH
THE EVENING BUT AM EXPECTING CONDS TO DETERIORATE AT KCLL/KUTS AND
KGLS THROUGH THE AFTERNOON AS CONVECTION MOVES TOWARD THE
PERIPHERY OF THE HGX CWA. LEANED TOWARD A HRRR/NAM12 AND RAP BLEND
WHICH SETS UP LOW LEVEL CONVERGENCE WITH EAST WINDS OVER LAND AND
SE WINDS OVER THE WATER. SHRA SHOULD REDEVELOP SOUTH OF I-10
BETWEEN 08-11Z FRIDAY AND EXPAND INLAND. GFS LOOKS TO BE TOO
AGGRESSIVE WITH DRYING FRI MORNING. 43
&&
.PREV DISCUSSION... /ISSUED 1042 AM CDT THU SEP 18 2014/
UPDATE...
ANOTHER DAY OF SLOW-MOVING CLUSTERS OF MODERATE TO HEAVY RAIN
CELLS...WITH EMBEDDED THUNDERSTORMS...THAT HAVE PRODUCED NUISANCE
FLOODING AROUND HOUSTON METRO. COMMUNITIES OF WESTERN HARRIS...
SOUTHEASTERN MONTGOMERY...AND SOUTHERN SAN JACINTO COUNTIES HAVE
RECEIVED THE HIGHEST RAINFALL THIS MORNING. UPPER LAYER SOIL
SATURATION INDICATES THAT THE SOUTHEASTERN CWA ARE THE COUNTIES
THAT CAN PICK UP THE LEAST AMOUNT OF RAINFALL BEFORE DEALING WITH
FLOODING ISSUES. THE CORE RAINS ARE MOVING A LITTLE FASTER OFF TO
THE NORTHEAST AT 15 TO 20 MPH...AND THIS IS THE GOOD NEWS. THE
LESS GOOD NEWS IS THAT THERE IS WESTERN COUNTY PRECIPITATION RE-
DEVELOPMENT...WITH AN APPROACHING NORTH CENTRAL TEXAS SHORTWAVE
DISTURBANCE EMBEDDED WITHIN THE MID-LEVEL SOUTHEASTERLY STEERING
FLOW. THE AIR MASS REMAINS UNCHANGED AND...OTHER THAN SOME BRIEF
MOMENTS OF RESPITE AFTER PASSING RAIN AS THE ATMOSPHERE QUICKLY
RE-CHARGES...THE SITUATION WILL BE OF RETURNING PRECIPITATION. IT
ALL DEPENDS UPON THE NEAR TERM AREAL EXTENT AND IMPACT OF AFTERNOON
RAIN/STORM ACTIVITY OVER THE NEXT 6 HOURS IN DETERMINING WHETHER
THE FLOOD WATCH NEEDS TO BE EXTENDED INTO FRIDAY. RAIN AND OVERCAST
EQUATE TO MANY ONLY ACHIEVING THE MID 80S FOR MAXIMUM TEMPERATURES.
AS OF NOW...IT APPEARS THAT FRIDAY WILL BE A TRANSITION DAY TO
RELATIVELY DRIER WEEKEND CONDITIONS. HIGHER RAIN CHANCES SHOULD BE
FOCUSED ALONG THE COAST AND POINTS SOUTHWESTWARD...OR WHERE THE
HIGHER MOISTURE RESIDES. THIS ASSUMPTION IS BASED UPON A DRIER AIR
AIR MASS OVER THE SABINE REGION MODELED TO PUSH INTO THE EASTERN
CWA BEHIND A VERY WEAK NORTHEASTERN BOUNDARY PASSAGE EARLY FRIDAY
MORNING. 31
PREV DISCUSSION... /ISSUED 455 AM CDT THU SEP 18 2014/
DISCUSSION...
WET FCST TO CONTINUE TODAY BUT WITH A CONTINUED THREAT OF FLOODING.
GROUNDS WET FROM RAINS THE PREVIOUS FEW DAYS ALONG WITH THE POTENTIAL
OF ADDITIONAL RAINS TODAY WILL KEEP THE FLOOD WATCH IN PLACE THROUGH
THIS EVENING.
ALREADY SEEING DEVELOPMENT OVER THE NEARSHORE WATERS THIS MORNING
AS THE CONTINUED WAA FLOW COLLIDES WITH THE MORE S/SE MOVING DISTURBANCE
COMING OUT OF SOUTH CENTRAL TX. ALSO SEEING HINTS OF YET ANOTHER
DISTURBANCE TRYING TO DIVE DOWN FROM NORTH TX. THESE SYSTEMS COMBINED
WITH THIS STILL VERY MOIST/TROPICAL AIR MASS ALREADY IN PLACE SHOULD
PRODUCE WIDESPREAD CONVECTION ACROSS THE CWA THRU THIS AFTN/EVE.
PER THE LATEST MODEL RUNS...THE REST OF THE WEEK/WEEKEND FORECAST SHOULD
SEE SOME DRYING BUT CONSENSUS NOT AS STRONG WITH THIS NEXT COLD FRONT
EARLY NEXT WEEK. PROGS APPEAR TO BE HAVING ISSUES WITH THE HANDLING
OF THE REMNANTS OF ODILE AND MAY BE EXAGGERATING ITS IMPACT ON THE
MAIN UPPER FLOW/PATTERN. AS SUCH WILL NOT BE CHANGING THE EXTENDED
FCSTS (TOO MUCH) OF FROPA MON (ALONG WITH COOLER AND DRIER CONDTIONS
NEXT WEEK). 41
MARINE...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS MORNING
AND MAY HAVE A CLUSTER MOVE INTO THE COASTAL WATERS THIS AFTERNOON
WITH GUSTY WINDS. SOUTHEAST WINDS WILL BECOME MORE EASTERLY ON
FRIDAY...AND INCREASE FRIDAY NIGHT AND SATURDAY. WEAK HIGH
PRESSURE SETTLES OVER SETX/LA AND WINDS SHOULD SLOWLY RELAX ON
MONDAY. A COLD FRONT SHOULD (IF THE ECMWF IS CORRECT-FAVORING IT
ATTM) MOVE INTO THE COASTAL WATERS ON TUESDAY OF COURSE DEPENDING
ON HOW WELL THE MODELS HANDLE ODILE AND THE NEXT TROUGH THROUGH
THE EASTERN U.S.. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 71 88 71 91 73 / 60 50 20 30 20
HOUSTON (IAH) 71 88 72 90 74 / 60 70 20 30 20
GALVESTON (GLS) 77 86 79 88 79 / 60 60 30 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...31
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1231 PM CDT THU SEP 18 2014
.DISCUSSION...UPDATED FOR 18Z AVIATION.
&&
.AVIATION...VICINITY THUNDERSTORMS FOR KVCT AND KCRP THIS
AFTERNOON DUE TO ONGOING AND ANTICIPATED CONVECTIVE ACTIVITY.
RAIN CHANCES ARE HIGHER FOR KVCT. CONSIDERED PUTTING A MENTION OF
VCTS OR VCSH AT KALI...BUT WITH POP GRIDS SITTING AT 20% LEFT OUT
OF THE TAF FOR CONSISTENCY`S SAKE. ACTIVITY WILL TAPER OFF AFTER
SUNSET...LEAVING CIRRUS BLOWOFF IN ITS WAKE...PARTICULARLY OVER
THE EASTERN THREE TERMINALS. VFR CIGS AND VIS WILL LIKELY GIVE WAY
TO MVFR CIGS/VIS AT KLRD AND KVCT. HAVE INCLUDED TEMPO IFR AT KALI
DUE TO TRENDS OVER THE PAST COUPLE OF DAYS AND NO SIGNIFICANT
CHANGES TO THE SYNOPTIC PATTERN.
&&
.PREV DISCUSSION... /ISSUED 639 AM CDT THU SEP 18 2014/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...CONVECTION TO THE NNW OF THE VCT TERMINAL CONTINUES
TO SINK TO THE SSE THIS MORNING. HAVE INCLUDED VCSH REMARKS AS
CONFIDENCE IS NOT HIGH THAT THIS ACTIVITY WILL DIRECTLY IMPACT THE
TERMINAL. INTERMITTENT MVFR CIGS/VSBYS WILL BE POSSIBLE AT ALI/LRD
FOR A FEW HOURS THIS MORNING BEFORE A RETURN TO VFR CONDITIONS.
WEAK S/W TROUGH WILL CONTINUE TO SLIDE TO THE SE TODAY...WITH
ADDITIONAL CHANCES FOR SHOWERS AND STORMS. HAVE INCLUDED VCTS
REMARKS AT ALI/CRP/VCT WITH BEST CHANCES AT THE VCT TAF SITE.
PREV DISCUSSION... /ISSUED 416 AM CDT THU SEP 18 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...AREA OF SLOW MOVING SHOWERS
AND THUNDERSTORMS ASSOCIATED WITH SHORTWAVE TROUGH CONTINUES TO
SLOW SAG TO SOUTH THIS MORNING. LATEST HRRR KEEPS THIS ACTIVITY
NORTH OF THE REGION AS THE MORNING PROGRESSES...BUT WILL CONTINUE
TO MONITOR TRENDS WITH THIS COMPLEX. UPPER DISTURBANCE WILL SHIFT
TO THE SOUTHEAST TODAY. THE BEST SUPPORT AND LOW LEVEL CONVERGENCE
WILL REMAIN OVER THE VICTORIA CROSSROADS REGION...AND HAVE PLACED
THE HIGHEST POPS OVER THIS AREA. FURTHER TO THE WEST AND SOUTHWEST
SUFFICIENT MOISTURE WILL REMAIN IN PLACE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS. AS WITH THE LAST SEVERAL DAYS...THREAT
FOR LOCALLY HEAVY RAIN WILL BE POSSIBLE. PW VALUES WILL REMAIN AT
OR ABOVE 2 INCHES TONIGHT INTO FRIDAY. ANOTHER WEAK DISTURBANCE IN
NW FLOW ALOFT WILL MOVE ACROSS CENTRAL TEXAS ON FRIDAY...RESULTING
IN ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. TEMPERATURES
TODAY AND FRIDAY WILL RANGE FROM THE MIDDLE 90S OVER THE RIO
GRANDE PLAINS WITH UPPER 80S TO LOWER 90S OVER THE VICTORIA
CROSSROADS WHERE BETTER CHANCES OF RAIN WILL EXIST.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...SURFACE HIGH PRESSURE
BEGINS TO NUDGE INTO THE REGION FROM THE NORTHEAST WITH PWATS
EXPECTED TO SLOWLY DECLINE THROUGH THE WEEKEND. NONETHELESS...THERE
WILL STILL BE ENOUGH MOISTURE AVAILABLE TO LEAD TO ISOLATED TO
SCATTERED DIURNAL ACTIVITY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
CONCERNING THE ADVERTISED COLD FRONT NEXT WEEK...MODEL DISAGREEMENTS
CONTINUE. THE NEXT UPPER TROUGH WILL SWING EAST THROUGH THE CENTRAL
PLAINS WITH THE ASSOCIATED FRONTAL BOUNDARY TO FOLLOW. THE ECMWF
KEEPS THE MAIN TROUGH WELL TO THE NORTH WHICH WOULD SUGGEST LITTLE
TO NO AFFECT FROM THE BOUNDARY. HOWEVER THE GFS AND CMC MAINTAIN A
SLIGHTLY SOUTHERN POSITION WHICH WITH THE AIDE OF A SURFACE LOW
ACROSS THE CENTRAL PLAINS...WOULD HELP ELONGATE THE FRONTAL BOUNDARY
INTO SOUTH TEXAS. WITH A MORE NORTH TO SOUTH FLOW IN
MIDLEVELS...WILL CONTINUE TO BRING THE FRONT THROUGH THE REGION
MONDAY NIGHT/TUESDAY KEEPING A SLIGHT CHANCE THROUGH TUESDAY BEFORE
DRYING THINGS OUT FOR THE REST OF THE WEEK. AS FOR
TEMPERATURES...KEPT NEAR TO SLIGHTLY ABOVE GUIDANCE THROUGH THE
PERIOD...WITH THE EXCEPTION OF COOLER CONDITIONS WITH THE FRONTAL
BOUNDARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 77 91 76 91 75 / 20 40 20 20 20
VICTORIA 75 91 74 93 75 / 30 50 10 30 10
LAREDO 77 96 78 96 78 / 20 30 20 30 20
ALICE 76 93 74 93 75 / 20 40 10 30 10
ROCKPORT 78 90 78 90 78 / 30 40 20 20 20
COTULLA 76 95 76 96 76 / 30 30 20 30 10
KINGSVILLE 76 93 75 93 75 / 20 40 10 30 10
NAVY CORPUS 80 89 79 91 79 / 20 40 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
IB/90...AVIATION
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 241 PM CDT THU SEP 18 2014
BREEZY AND MILD THE NEXT COUPLE DAYS...THEN COOLER AGAIN FOR THE
LATTER PART OF THE WEEKEND AND EARLY NEXT WEEK.
DEAMPLIFICATION OF THE FLOW ACRS NOAM WL CONT A BIT LONGER...THEN
THE PATTERN WL IMMEDIATELY GO BACK INTO AN AMPLIFICATION PHASE...
WHICH WL PEAK EARLY NEXT WEEK...AS A GRADUAL PROGRESSION OF THE
LARGE SCALE FEATURES CONTINUES. THE MAIN WESTERLIES WL RECEDE NWD
INTO CANADA BY LATE IN THE PERIOD.
TEMPERATURES WL BE ON SOMEWHAT OF A ROLLERCOASTER...WITH MAXES
MAINLY VARYING BETWEEN NORMAL AND ABOVE NORMAL...WHILE MINS VARY
BETWEEN NORMAL AND BELOW NORMAL. PCPN TOTALS FOR THE PERIOD WL
DEPEND PRIMARILY ON WHAT FALLS IN THE NEXT 24-48 HRS...AND WL MOST
LIKELY END UP AOB NORMAL.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 241 PM CDT THU SEP 18 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LAST
NIGHTS COLD FRONT HAS STALLED OVER SOUTHERN MINNESOTA TO SOUTHERN
WISCONSIN TO SOUTHERN LOWER MICHIGAN EARLY THIS AFTERNOON. NORTH
OF THIS BOUNDARY...WIDESPREAD LOW STRATUS REMAINS SOLID OVER MUCH
OF WISCONSIN EXCEPT FOR FAR NORTHEAST WISCONSIN WHERE CANADIAN
HIGH PRESSURE IS NOSING SOUTH. ANTICIPATE THESE CLOUDS TO RETURN
NORTHWARD LATER THIS AFTERNOON AS THE SURFACE HIGH RETREATS
NORTHEAST. THE NEXT SHORTWAVE IS MOVING EAST OVER SOUTHEAST
BRITISH COLUMBIA AND WILL ENTER THE GREAT LAKES REGION TOMORROW.
CLOUD TRENDS ARE THE FIRST FORECAST CONCERN TONIGHT...FOLLOWED BY
PRECIP CHANCES TOMORROW.
TONIGHT...THE COLD CANADIAN HIGH RETREATS TO THE NORTHEAST AS
MID-LEVEL HEIGHT FALLS MOVE INTO THE NORTHERN PLAINS. WITH RETURN
FLOW STRENGTHENING...LOW LEVEL TEMPS WILL SLOWLY MODERATE AS THE
COLD FRONT RETURNS NORTHEAST...WHICH WILL HELP DISSIPATE THE LOW
STRATUS DECK FROM SOUTHWEST TO NORTHEAST. NORTH-CENTRAL WISCONSIN
SHOULD SEE THE CLOUDS DISSIPATE LAST. IF AND WHERE SKIES DO CLEAR
FOR A PERIOD (MOST LIKELY OVER CENTRAL AND EAST-CENTRAL
WISCONSIN)...SOME POSSIBILITY OF LOW STRATUS REDEVELOPING AS
MOISTURE WILL REMAIN TRAPPED BENEATH A LOWERING INVERSION AND WINDS
SHOULD NOT DECOUPLE. CONFIDENCE IS LOW THAT THIS WILL OCCUR SO WILL
LEAVE OUT OF THE FORECAST. SHOULD SEE A WARMER NIGHT WITH LOWS
MAINLY IN THE LOWER TO MIDDLE 40S.
FRIDAY...AS LOW CLOUDS CONTINUE THEIR RETREAT TO THE NORTHEAST...MID
AND HIGH CLOUDS WILL BE INCREASING DURING THE MORNING AHEAD OF
SHORTWAVE ENERGY MOVING EAST OUT OF NORTHERN MINNESOTA INTO LAKE
SUPERIOR. THE TAIL END OF THAT VORT MAX MAY CREATE A FEW SHOWERS
AND AN ISOLATED THUNDERSTORM OVER NORTH-CENTRAL AND FAR NE WISCONSIN
DURING THE AFTERNOON. HIGH TEMPS WILL BE CONSIDERABLY WARMER
DESPITE PLENTY OF MID AND HIGH CLOUDS AND WILL GO WITH A RANGE FROM
THE MIDDLE 60S NORTH TO LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 241 PM CDT THU SEP 18 2014
FRONTAL SYSTEM WL BE APPROACHING THE AREA FRI NGT AND CROSS THE
AREA SAT. LARGE SCALE UPR TROF WL BE AMPIFYING AS IT ACCOMPANIES
THE FRONT ACRS THE AREA. SO LARGE SCALE FORCING FOR PCPN WL BE
DECENT. A BIT CONCERNED HOWEVER THAT THE RETURN OF MOISTURE FM THE
S IS BEING OVERESTIMATED BY THE GUIDANCE. STUCK CLOSE TO PREV FCST
WITH POPS...WHICH BASICALLY MEANT HAVING LIKELY POPS IN THE N AND
CHC POPS IN THE S. LOW-LEVEL WINDS START TO VEER AHEAD OF THE SFC
FRONT ON SAT...CUTTING DOWN ON THE CONVERGENCE ALONG THE BOUNDARY.
MODELS SEEM TO HAVE CAUGHT ON TO THIS BY SHOWING ONLY LIMITED PCPN
WITH THE FRONT AS IT CROSSES THE AREA...WITH THE BEST DEVELOPMENT
OCCURRING TO OUR S AND E LATE IN THE DAY. THIS ALSO FITS WITH
SPC/S SWODY3 OUTLOOK WHICH INDICATED A 5 PCT CHC OF SVR OVER SERN
WI.
UPR SPEED MAX AND SECONDARY SHRTWV WL DIG ACRS THE AREA SAT NGT...
WITH SECONDARY SFC BOUNDARY LIKELY DROPPING THROUGH ON SUN. THESE
FEATURES WL KEEP THE CHC FOR SHRA ALIVE...ESP ACRS THE N. WENT
WITH THE HIGHEST POPS ACRS THE N IN BOTH PERIODS.
UPPER RIDGING BUILDING INTO THE AREA COMBINED WITH SFC HIGH
PASSING TO OUR SW FOR THE EARLY TO MIDDLE PART OF NEXT WK WL LEAD
TO A PERIOD OF QUIET AUTUMN WEATHER. TEMPS WL START OUT A LITTLE
COOL AND THEN MODERATE. THE DRY AIR WL ALLOW AFTN MAXES TO WARM TO
ABV NORMAL LEVELS...WHILE NIGHT TIME LOWS DROP TO AOB NORMAL. MADE
A FEW TWEAKS TO THE EXTENDED FCST INITIALIZATION GRIDS TO BETTER
DEPICT THE ABV MENTIONED TEMPERATURE TRENDS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1137 AM CDT THU SEP 18 2014
PLENTY OF MVFR AND IFR BKN/OVC CIGS NORTH OF A STALLED
COLD FRONT ACROSS THE REGION. THOUGH CIGS SHOULD RISE TO MVFR
EVERYWHERE THIS AFTERNOON...THE CLOUDS WILL BE SLOW TO DISSIPATE
TONIGHT UNTIL WARMER LOW LEVEL AIR ARRIVES. THIS WARMER AIR WILL
GRADUALLY MOVE FROM NORTH TO SOUTH ACROSS THE REGION LATE THIS
EVENING AND OVERNIGHT. IF SKIES DO CLEAR FOR A PERIOD...THERE WILL
BE POTENTIAL FOR LOW STRATUS TO REDEVELOP BUT CONFIDENCE IS LOW.
ANY LINGERING LOW CIGS TO IMPROVE QUICKLY TO VFR FRIDAY MORNING
THOUGH MID AND HIGH CLOUDS WILL BE ON THE INCREASE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1236 PM CDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERNS TODAY ARE CLOUD TRENDS.
LATEST 08Z SURFACE ANALYSIS SHOWS WEAK COLD FRONT EXTENDING FROM
EASTERN WISCONSIN INTO WESTERN MINNESOTA. LATEST FOG PRODUCT
SATELLITE IMAGERY INDICATES LOW LEVEL STRATUS OVER PORTIONS OF
NORTHERN AND EASTERN HALF OF WISCONSIN AND EAST CENTRAL
MINNESOTA. THIS LOW LEVEL STRATUS IS MOVING SOUTH AND WEST BEHIND
THE WEAK SURFACE FRONT.
THE 18.00Z GFS/NAM AND 18.06Z RAP APPEAR INITIALIZE AND HANDLE
MOVEMENT/EXPANSION OF LOW LEVEL STRATUS WELL INTO WESTERN WISCONSIN
EARLY THIS MORNING/TODAY PER THE 925MB RELATIVE HUMIDITY FIELDS. THE
BIG QUESTION WILL BE HOW LONG WILL THE LOW LEVEL STRATUS HANGS
AROUND THE FORECAST AREA TODAY. THE 18.00Z GFS/NAM AND 18.06Z RAP
SUGGEST THE CLOUDS WILL ERODE DUE TO DAYTIME HEATING AND LIFT BACK
NORTH INTO NORTHERN WISCONSIN AROUND 18Z TODAY. IF LOW LEVEL STRATUS
ERODES LATER IN THE AFTERNOON...THIS WILL HAVE IMPACTS ON FORECAST
HIGH TEMPERATURES FOR TODAY...ESPECIALLY OVER EASTERN PART OF THE
FORECAST AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY INTO SATURDAY
NIGHT. THE LATEST 18.00Z GFS/NAM/ECMWF SHOW DECENT ISENTROPIC LIFT
AT 305K SURFACE BETWEEN 12-18Z FRIDAY AND ASSOCIATED 925-850MB
MOISTURE TRANSPORT INTO THE WESTERN FORECAST AREA. THE COMBINATION
OF ELEVATED INSTABILITY OF 0-6KM MOST UNSTABLE CAPE OF 300-800
J/KG OVER THE WESTERN FORECAST AREA AND THIS LIFT...WARRANTS A
SMALL PRECIPITATION CHANCE OVER THE WESTERN FORECAST AREA BETWEEN
12-18Z FRIDAY.
AFTER THIS INITIAL WEAK IMPULSE IN ASSOCIATION WITH WARM AIR
ADVECTION...THE 18.0ZZ GFS/NAM/ECMWF INDICATE MUCH OF THE
SOUTHERN FORECAST AREA BECOMES CAPPED AFTER 18Z FRIDAY...AS
SHORTWAVE RIDGE BUILDS INTO THE AREA AND FOCUSES LIFT/MOISTURE
TRANSPORT INTO NORTHERN WISCONSIN. HAVE ADJUSTED PRECIPITATION
CHANCES FURTHER NORTH AFTER 18Z FRIDAY. THE CAP BEGINS TO WEAKEN
AFTER 00Z SATURDAY ACROSS THE FORECAST AREA...IN ADDITION SURFACE
FRONT PUSHES ACROSS FORECAST AREA AND DEEP FORCING/MOISTURE
TRANSPORT/CONVERGENCE WILL ALLOW SHOWERS AND THUNDERSTORMS TO
DEVELOP IN THE 00-06Z SATURDAY TIMEFRAME AND MOVE NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT. ANY SEVERE THREAT
WITH THE THUNDERSTORMS LOOKS TO BE CONFINED NORTH OF THE
INTERSTATE 90 CORRIDOR...WHERE THE BETTER INSTABILITY AND SHEAR
WILL BE OVER THE FORECAST AREA. AT THIS TIME...THE SEVERE THREAT
LOOKS TO BE ISOLATED AND THE MAIN THREATS WOULD BE LARGE HAIL AND
DAMAGING WINDS.
SURFACE FRONT/SHORTWAVE TROUGH PUSHES SOUTH AND EAST OF FORECAST
AREA SATURDAY AND TAKING THE BULK OF LIFT AND BETTER INSTABILITY
SOUTH AND EAST OF FORECAST AREA. THE REGION WILL BE UNDER THE
INFLUENCE OF CYCLONIC FLOW SATURDAY...WITH STEEPENING LAPSE RATES
AND A COUPLE HUNDRED ELEVATED CAPE PER BUFKIT SOUNDINGS. SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ACROSS THE FORECAST
AREA. HAVE LEFT SMALL PRECIPITATION CHANCES IN THE FORECAST.
UPPER LEVEL TROUGH BEGINS TO BREAK DOWN OVER THE GREAT LAKES
REGION AND HEIGHTS RISE OVER THE NORTHERN PLAINS LATE SUNDAY INTO
THE MIDDLE OF NEXT WEEK. THE 18.00Z GFS/ECMWF ARE INDICATING
UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES BY 00Z
THURSDAY. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL EARLY TO
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM CDT THU SEP 18 2014
AN IFR/MVFR STRATUS FIELD HAS SLOWLY LIFTED TO THE NORTHEAST IN
WESTERN WISCONSIN WITH LSE NOW INTO VFR CONDITIONS. SOME VFR CU
WILL FORM THIS AFTERNOON BEFORE SKIES CLEAR OUT TONIGHT. WINDS
WILL BE ON THE INCREASE OVERNIGHT AS A RIDGE OF HIGH PRESSURE
SHIFTS TO THE EAST AND THE PRESSURE GRADIENT TIGHTENS UP ACROSS
THE REGION. THIS SHOULD HELP TO KEEP ANY FOG FROM FORMING
OVERNIGHT...BUT WILL HAVE TO WATCH FOR ANY POSSIBLE LOW STRATUS
THAT COULD FORM UNDER THE INVERSION. RIGHT NOW...IT APPEARS THAT
THE BETTER CHANCES FOR THIS STRATUS WILL BE IN NORTHERN WISCONSIN
AND FURTHER TO THE WEST...SO WILL KEEP SKIES CLEAR OVERNIGHT.
WINDS WILL PICK UP QUICKLY IN THE MORNING WITH SOME GUSTS IN THE
20-30KT RANGE EXPECTED OUT OF THE SOUTH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1145 AM MDT THU SEP 18 2014
.UPDATE...
ISSUED AT 1006 AM MDT THU SEP 18 2014
FOG HAS BEEN LIFTING ACROSS THE PANHANDLE LATE THIS MORNING. WENT
AHEAD AND TOOK FOG OUT OF THE FORECAST THE REST OF THE MORNING.
UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH NOON FRIDAY)
ISSUED AT 1145 AM MDT THU SEP 18 2014
FOG AND LOW STRATUS HAVE LIFTED ACROSS PORTIONS OF THE NEBRASKA
PANHANDLE LATE THIS MORNING...WITH VFR CONDITIONS EXPECTED THROUGH
THE DAY AND INTO TONIGHT. WINDS SHOULD REMAIN RELIATVELY LIGHT TODAY
WITH SOUTH WINDS STRENGTHENING OVER THE NEBRASKA PANHANDLE TONIGHT
AS A SURFACE LOW MOVES EASTWARD OVER THE NORTHERN GREAT PLAINS. VFR
CONDITIONS WILL PREVAIL ACROSS SOUTHEAST WYOMING THROUGH THE PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...TJT
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1008 AM MDT THU SEP 18 2014
.UPDATE...
ISSUED AT 1006 AM MDT THU SEP 18 2014
FOG HAS BEEN LIFTING ACROSS THE PANHANDLE LATE THIS MORNING. WENT
AHEAD AND TOOK FOG OUT OF THE FORECAST THE REST OF THE MORNING.
UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 526 AM MDT THU SEP 18 2014
NEBRASKA TAFS...AREAS OF IFR CEILINGS AND VISIBILITIES IN LOW
CLOUDS AND FOG THROUGH 9 AM...OTHERWISE VFR PREVAILS. WIND GUSTS
OF 20 TO 30 KNOTS LATE THIS MORNING AND THIS AFTERNOON.
WYOMING TAFS...VFR PREVAILS. WIND GUSTS OF 20 TO 30 KNOTS LATE
THIS MORNING AND THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...JAMSKI