Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/19/14
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
149 PM CDT WED SEP 17 2014
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
AREA OF SHRA/TSRA ONGOING ACROSS SRN MO IS BEGINNING TO ACCELERATE
AS THE STRONGEST CELLS ALONG THE WRN HALF OF THIS COMPLEX DROPS SOUTH
INTO AR. SEVERAL OF THE RECENT RUNS OF THE HIGH-RES HRRR HAVE DONE A
REASONABLE JOB ON THESE FEATURES...AND SHOW THIS ACTIVITY DROPPING
GENERALLY SOUTH THROUGHOUT THE AFTERNOON HRS. EXPECTING THIS
ACTIVITY TO GENERALLY FOLLOW THE HIGHER INSTABILITY AXIS ACROSS
THE WRN HALF TO TWO-THIRDS OF THE STATE WHERE MOST UNSTABLE CAPE
VALUES ARE ON THE ORDER OF 1-3K J/KG AT THIS HR. AS A RESULT...DO
HAVE HIGHEST POPS THROUGH MID AFTERNOON OVER THE NRN AND NWRN
SECTIONS OF THE CWA...THEN DROPPING SOUTH TO SW OVER TIME LATER
THIS AFTERNOON. THE HRRR SOLUTIONS EVEN KEEP THIS ACTIVITY GOING
INTO THE SWRN SECTIONS OF THE AREA BY THIS EVENING...SO HAVE
GENERALLY FOLLOWED THIS TREND WITH POPS. HOWEVER...DO DROP POPS
OVER TIME AS UNCERTAINTY IN COVERAGE AN INTENSITY INCREASES BY
LATE THIS EVENING REGARDING THIS ONGOING CONVECTIVE ACTIVITY.
BEYOND THIS EVENING...THE TIMING AND PLACEMENT OF WHAT MAY BE THE
NEXT UPPER DISTURBANCE MOVING OVER THE STATE BECOMES A BIT
UNCERTAIN. EARLIER SHORT TERM MODEL SOLUTIONS HAVE THE NEXT WAVE
MOVING OVER LATE TONIGHT INTO THU MORNING...BUT THIS MAY NOT BE THE
CASE WITH THE ONGOING ACTIVITY AND ITS EXPECTED PATH. THE NEXT WAVE
MAY BE DELAYED A BIT LONGER...BUT MAY ALSO NOT BE AS INTENSE AS
EARLIER EXPECTED. WITH THAT SAID...CONTINUE WITH GENERALLY LOCATION
OF CHANCE POPS FOR MUCH OF THU...BUT HAVE DECREASED POPS SOME AS A
RESULT OF THE UNCERTAINTY OF WHEN/WHERE THE NEXT WAVE MAY MOVE.
BY FRI INTO EARLY SAT...AN UPPER RIDGE WILL MOVE OVER THE
REGION...DECREASING POPS AND INCREASING TEMPS ACROSS THE STATE. BY
LATE IN THE PERIOD THOUGH...HAVE INCREASING POPS WITH THE APPROACH
OF AN UPPER LOW OR THE REMNANTS OF ODILE AS THEY APPROACH FROM THE
WEST/NW.
&&
.LONG TERM...SUNDAY THROUGH WEDNESDAY
A COLD FRONT WILL BE MAKING ITS WAY THROUGH THE STATE AT THE START
OF THE LONG TERM...WITH SOME RAIN CHANCES MAKING THEIR WAY INTO THE
AREA THROUGH MONDAY AFTERNOON. THOUGH...LATEST MODEL SOLUTIONS SEEM
LESS AMBITIOUS ABOUT WIDESPREAD RAINFALL IN THE STATE.
AS RAIN CHANCES DISSIPATE BY MONDAY...COOLER AIR WILL FILTER INTO THE
STATE. BOTH HIGH AND LOW TEMPERATURES WILL BE FAIRLY NORMAL TO
SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF SEPTEMBER IN ARKANSAS.
WINDS WILL GENERALLY BE OUT OF THE NORTH THROUGH THE EXTENDED PERIOD
AND A COOL NORTHWEST FLOW ALOFT WILL BE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 64 80 62 83 / 30 30 10 10
CAMDEN AR 71 88 68 89 / 40 40 20 10
HARRISON AR 63 78 61 80 / 40 30 10 10
HOT SPRINGS AR 69 86 67 85 / 50 30 20 10
LITTLE ROCK AR 69 85 66 86 / 50 30 20 10
MONTICELLO AR 71 88 67 88 / 30 30 20 10
MOUNT IDA AR 67 85 65 84 / 40 30 20 10
MOUNTAIN HOME AR 63 78 60 81 / 30 30 10 10
NEWPORT AR 64 80 61 83 / 30 30 10 10
PINE BLUFF AR 70 87 66 87 / 40 30 20 10
RUSSELLVILLE AR 67 85 65 84 / 40 30 10 10
SEARCY AR 66 82 63 83 / 40 30 10 10
STUTTGART AR 68 84 65 85 / 40 30 20 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...62 / LONG TERM...226
AREA FORECAST DISCUSSION
NWS RENO NV
811 PM PDT THU SEP 18 2014
.UPDATE...
WESTERLY WINDS ARE STARTING TO DECREASE OVER WRN NV THIS EVENING
AND BEGINNING A SLOW SHIFT TO THE WNW OR NW. DURING THE LAST HOUR
VISIBILITY HAS STARTED TO IMPROVE OVER THE RENO AREA BUT REMAINS
LOW IN SOME OTHER SPOTS. THE LESSENING OF THE WINDS SHOULD HELP
THIS PROCESS AS LESS SMOKE IS ADVECTED INTO THE REGION THROUGH THE
NIGHT. CONVECTION HAS DECREASED QUITE A BIT OVER WRN NV AND
CHANGES WERE MADE TO DROP THE CONVECTION FOR NE CA LATE THIS
EVENING.
LATEST WATER VAPOR IMAGERY IS SHOWING THE UPPER LOW MAY BE TRYING
TO CLOSE OFF A LITTLE FARTHER WSW THAN ORIGINALLY FORECAST. THIS
WOULD BE IN RESPONSE TO A JET STREAK DIGGING INTO THE BACK SIDE OF
THE TROUGH. THIS WOULD MAKE THE FORECAST A BIT MORE PROBLEMATIC
OVERNIGHT. LATEST NAM STILL WANTS TO DEVELOP PCPN IN A DEFORMATION
BAND OVER WRN NV. THIS WAS MAINTAINED...BUT IF LOW CLOSES OFF
FARTHER WEST THEN WE MAY BE TOO FAR EAST TO SEE MUCH OF THIS PCPN.
AND...THIS COULD ALSO DELAY THE INCREASE IN LOW TO MID LVL EASTERLY
FLOW THAT WOULD HELP TO MOVE THE SMOKE OUT OF OUR AREA. FOR NOW
WILL BANK ON MOST OF THE SMOKE DISSIPATING BY DAYBREAK. 20
&&
.PREVIOUS DISCUSSION... /ISSUED 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 DENVER/BOULDER CO
221 PM MDT WED SEP 17 2014
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 220 PM MDT WED SEP 17 2014
CONVERGENCE BOUNDARY CONTINUES TO SPARK SCATTERED SHOWERS AND
THUNDERSTORMS OVER ELBERT AND LINCOLN COUNTIES THIS AFTERNOON.
ADDITIONAL OUTFLOW BOUNDARIES FROM THE SHOWERS WILL HELP TO AID
IN ADDITIONAL DEVELOPMENT FOR THE REST OF THE AFTERNOON AND EARLY
EVENING. THE OTHER AREA FOR POTENTIAL STORMS IS OVER THE
CYS RIDGE AND FAR NORTHEAST PLAINS. STRONGER STORMS IN WYOMING
EXPECTED TO MOVE INTO THE FAR NE PLAINS LATER THIS AFTERNOON AND
TAP INTO A BIT HIGHER LOW LEVEL MOISTURE. THIS MAY LEAD TO A
STRONGER/POTENTIAL ISOLATED SEVERE STORM WITH SURFACE BASED CAPES
OF 800-1500J/KG. LATEST HRRR STILL SUGGESTS ISOLATED THUNDERSTORMS
OVER THE NE PLAINS AND WILL EXPAND COVERAGE A BIT FOR EVENING
FORECAST BASED ON LATEST TRENDS.
A RIDGE OF HIGH PRESSURE WILL CENTER ITSELF OVER CO ON THURSDAY.
INCREASING MID LEVEL SUBSIDENCE ASSOCIATED WITH THE RIDGE MAY NIX
AFTN TSTM COMPLETELY FM THE FORECAST. SOME LOW LOW MOISTURE IS
PROGGED TO ADVECT INTO THE NORTHEAST CORNER OF THE STATE LATE
TONIGHT AND EARLY THURSDAY MORNING SO WL KEEP THE MENTION OF
PATCHY FOG THERE AS WELL. HIGH TEMPERATURES SIMILAR TO
TODAY...MAYBE EVEN A DEGREE OR TWO WARMER WITH LESS SUBTROPICAL
MOISTURE AROUND.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1013 AM MDT WED SEP 17 2014
THE UPPER LEVEL RIDGE WILL BREAK DOWN AND MOVE EASTWARD THROUGH
FRIDAY. FLOW WILL BE FROM THE SSW WITH THE LOW OVER THE SW COMING
IN UNDER THE RIDGE. THIS SYSTEM WILL REMAIN TO THE SOUTH WITH MOST
OF THE MOISTURE COMING BEHIND THE SURFACE FRONT THAT WILL MOVE
THROUGH FRIDAY. THE FRONT WILL BRING IN STRONG SOUTHERLY FLOW TO
THE EASTERN PORTIONS OF THE REGION WITH INCREASED MOISTURE BEHIND
IT. THERE IS ALSO SOME WEAK QG LIFT BEHIND THE FRONT THAT WILL
ALLOW FOR SOME SHOWER/TS DEVELOPMENT OVER THE MOUNTAINS AND
FOOTHILLS FRIDAY AFTERNOON AND EVENING.
FOR SATURDAY SUBSIDENCE AND DOWNSLOPE WINDS BEHIND THE FRONT WITH
UPPER LEVEL RIDGING RETURNING WILL HELP TO DRY THINGS OUT AND KEEP
TEMPS AT OR JUST ABOVE SEASONAL NORMALS. ON SUNDAY FLOW AROUND THE
UPPER RIDGE WILL COMBINE WITH MOISTURE OUT AHEAD OF THE NEXT
SYSTEM MOVING INTO THE GREAT BASIN BY SUNDAY AFTERNOON TO KEEP THE
WEATHER UNSETTLED THROUGH THE PERIOD. FOR SUNDAY THERE IS A SLIGHT
CHANCE OF TS DURING THE AFTERNOON WITH TEMPS IN THE MID 70S
BECOMING COOLER ON MONDAY.
THE UPPER TROUGH/CLOSED LOW WILL TRACK IN BY MONDAY AFTERNOON
WITH PWS RANGING FROM 0.90-1.00 AND DEWPOINTS IN THE MID 50S BY
12Z MONDAY. THIS COMBINED WITH DECENT QG LIFT WILL BRING A GOOD CHANCE
OF WIDESPREAD SHOWERS/TS ON MONDAY THROUGH TUESDAY AS THE LOW
CONTINUES TO TRACK TOWARD THE NE. TEMPS WILL BE AT OR BELOW
SEASONAL NORMALS IN THE LOWER 70S AT THE START OF THE WEEK SLOWLY
INCREASING BY WEDNESDAY BACK TO THE UPPER 70S AND LOWER 80S.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1013 AM MDT WED SEP 17 2014
NO CIG/VSBY RESTRICTIONS OVER THE NEXT 24 HOURS. TYPICAL
DIURNAL WINDS EXPECTED AS WELL. ANY TSTM DEVELOPMENT THIS EVENING
WILL BE WELL TO THE EAST AND SOUTH OF DENVER.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN/COOPER
LONG TERM...BOWEN
AVIATION...COOPER
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
137 PM EDT WED SEP 17 2014
.UPDATE...
THE WINDS WILL REMAIN WESTERLY THIS AFTERNOON AT 5 TO 10 KNOTS
BEFORE DECREASING TO 5 KNOTS OR LESS TONIGHT AT ALL OF THE TAF
SITES. ISOLATED SHOWERS AND THUNDERSTORMS ARE DEVELOPING OVER THE
INTERIOR AREAS OF SOUTH FLORIDA EARLY THIS AFTERNOON. THIS
ACTIVITY WILL CONTINUE TO DEVELOP AND PUSH EAST INTO THE EAST
COAST METRO AREAS AFTER 19Z TODAY. SO WILL CONTINUE THE VCTS IN
THE EAST COAST TAF SITES WITH EVEN A TEMPO GROUP BETWEEN 19Z AND
21Z FOR REDUCE VIS AND CEILING...AS THE HRRR SHORT RANGE MODLES
ARE SHOWING SHOWERS AND THUNDERSTORMS AFFECTING THE EAST COAST TAF
SITES DURING THIS TIME FRAME.
THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD DISSIPATE AFTER 00Z
TONIGHT OVER THE EAST COAST TAF SITES. SO HAVE KEPT THE EAST COAST
TAF SITES DRY FOR TONIGHT.
KAPF TAF SITE SHOULD ALSO SEE SHOWER AND THUNDERSTORM ACTIVITY FOR
EARLY THIS AFTERNOON...AS A LINE OF SHOWERS AND THUNDERSTORMS ARE
MOVING SOUTHWEST TOWARD THIS TAF SITE. THEREFORE...A TEMPO GROUP
HAS ALSO BEEN ADDED FOR KAPF TAF SITE FROM 18Z UNTIL 20Z. THE
WEATHER AT KAPF TAF SITE SHOULD ALSO BECOME DRY TONIGHT AS THE
SHOWER AND THUNDERSTORM ACTIVITY DISSIPATES.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 951 AM EDT WED SEP 17 2014/
UPDATE...
MINOR CHANGES WERE MADE TO THE PREVIOUS FORECAST. THE LATEST
SHORT RANGE MODEL GUIDANCE LOOKS ON TRACK WITH SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE INTERIOR BY THE LATE MORNING AND
EARLY AFTERNOON HOURS AS A COLD FRONT CONTINUES TO MOVE THROUGH
NORTHERN AND CENTRAL FLORIDA. WITH THE SOUTHWESTERLY FLOW IN
PLACE, THESE SHOWERS AND THUNDERSTORMS WILL THEN MOVE OVER THE
EAST COAST METRO AREAS THROUGHOUT THE AFTERNOON AND THEN DISSIPATE
AS THEY MOVE OVER THE ATLANTIC COASTAL WATERS DURING THE EVENING.
THE STRONGEST STORMS COULD PRODUCE WIND GUSTS UP TO 40 MPH AS WELL
AS FREQUENT LIGHTNING. THEREFORE POPS HAVE BEEN RAISED A LITTLE
BIT OVER THE EAST COAST AND LOWERED A LITTLE BIT OVER THE WEST
COAST FOR TODAY.
&&
PREV DISCUSSION... /ISSUED 745 AM EDT WED SEP 17 2014/
UPDATE...
THE WIND FLOW TODAY WILL BE FROM THE WESTERLY DIRECTION AT ALL OF
THE TAF SITES WITH WIND SPEEDS OF 5 TO 10 KNOTS. SHOWERS AND
THUNDERSTORMS SHOULD START TO DEVELOP OVER THE WEST COAST LATE
THIS MORNING AND PUSH EAST ACROSS THE AREA THROUGH THE EARLY
AFTERNOON HOURS. THE SHOWERS AND THUNDERSTORMS SHOULD THEN BE
MOVING INTO THE EAST COAST TAF SITES BETWEEN 19Z AND 01Z TODAY.
SO VCSH WILL CONTINUE OVER THE EAST COAST TAF SITES FROM 15Z UNTIL
19Z BEFORE VCTS BETWEEN 19Z AND 01Z. FOR KAPF TAF SITE...VCTS FROM
16Z UNTIL 21Z THEN VCSH FOR REST OF THE EVENING HOURS.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS AT THIS TIME
FOR THE TAF SITES ACROSS SOUTH FLORIDA. HOWEVER...ANY SHOWERS AND
THUNDERSTORMS THAT DO MOVE THROUGH THE AREA COULD REDUCE THE
CEILING AND VIS DOWN TO MVFR CONDITIONS WHICH SHOULD ONLY LAST
ABOUT 30 MINUTES. IF IT LOOKS LIKE THE REDUCED VIS OR CEILING WILL
LAST LONGER WITH THE SHOWERS AND THUNDERSTORMS THEN A SHORT TEMPO
GROUP WILL BE NEEDED.
&&
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 411 AM EDT WED SEP 17 2014/
SHORT TERM...
HIGH PRESSURE OVER THE GULF IS WEAKENING AS A TROUGH OVER THE
EASTERN UNITED STATES DIGS SOUTH. THIS WILL KEEP MAINLY AFTERNOON
SHOWERS AND THUNDERSTORMS IN THE FORECAST TODAY. A BROAD LOW OVER
THE ATLANTIC, JUST OFF THE GEORGIA COAST, WILL SLOWLY DEEPEN AND
DRIFT EASTWARD THROUGH THE DAY TODAY. THE DEVELOPING LOW AND
UPPER LEVEL TROUGH HAVE CHANGED THE FLOW FROM NORTHERLY YESTERDAY
TO MORE WEST TO SOUTHWESTERLY TODAY. THIS WILL CAUSE MOST OF THE
CONVECTION TO BE IN THE INTERIOR AND EAST COAST, AS OPPOSED TO
THE GULF SIDE YESTERDAY. MODELS ARE SHOWING IT MAY BE A LITTLE
DRIER TODAY, WITH PWATS AROUND 1.8 INCHES, RATHER THAN JUST OVER 2
INCHES YESTERDAY. 500 MB TEMPS, ON THE NAM FORECAST SOUNDING,
LOOKS TO BE A LITTLE WARMER THAN YESTERDAY, WITH IT SITTING AROUND
-6.0C. NORMALIZED CAPE LOOKS TO BE AROUND .1, COMPARED TO THE .18
YESTERDAY. THAT WOULD INDICATE WEAK VERTICAL ACCELERATIONS. SO,
EXPECT SHOWERS TO DEVELOP THIS AFTERNOON. THUNDERSTORMS WILL ALSO
BE POSSIBLE, GIVEN THE UPPER LEVEL TROUGH IN THE AREA. MOST, IF
NOT ALL THE STORMS SHOULD BE GARDEN VARIETY THUNDERSTORMS TODAY.
BY TOMORROW, PWATS DO GO BACK TO JUST OVER 2 INCHES AND THERE IS
AN INVERTED TROUGH OVER SOUTH FLORIDA, ACCORDING TO THE GFS. THE
ECMWF DOESNT SHOW THE INVERTED TROUGH, BUT IT DOES HAVE WEAK LOW
PRESSURE OVER THE AREA. WINDS TOMORROW WILL BEGIN SOUTHWESTERLY,
BUT SHOULD TURN MORE SOUTHERLY IN THE LATE AFTERNOON. THIS WOULD
MAKE THE EASTERN LAKE REGION THE MOST LIKELY TO SEE ACTIVE
WEATHER TOMORROW. MODELS ALSO SHOW A WEAK COLD FRONT TRYING TO
PUSH SOUTH INTO THE AREA. HOWEVER, IT IS STILL PRETTY EARLY IN
THE SEASON FOR A FRONT AND WOULD NOT BE SURPRISED TO SEE IT STALL
OVER CENTRAL FLORIDA INSTEAD. BUT THIS WILL BRING SOME ADDITIONAL
INSTABILITY TO THE AREA, ESPECIALLY IN THE LAKE REGION.
AS WE MOVE FORWARD TO FRIDAY, MODELS ARE STILL INDICATING THE COLD
FRONT WILL PUSH SOUTH OF THE LAKE IN THE EARLY FRIDAY MORNING
HOURS. BUT AGAIN, IT MAY NOT MAKE IT THIS FAR SOUTH. BUT, AHEAD
OF IT THERE SHOULD BE GENERAL INSTABILITY AND WEAK SURFACE FLOW.
THIS SHOULD ALLOW FOR THE SEA BREEZE AND LAKE BREEZE TO DEVELOP.
THIS WILL CAUSE SOME AREAS OF CONVERGENCE FRIDAY, THAT WILL
TRIGGER CONVECTION BY THE AFTERNOON HOURS. PWATS REMAIN AROUND 2
INCHES AND THE UPPER LEVEL TROUGH DOES LOOK TO DIG FURTHER SOUTH.
SO, HAVE SOMEWHAT HIGHER POPS IN THE FORECAST FOR FRIDAY.WITH
LIGHT FLOW, AND PLENTY OF MOISTURE, THE SHOWERS AND STORMS COULD
BRING HEAVY RAIN AND POSSIBLY SOME MINOR URBAN FLOODING FRIDAY
AFTERNOON TO THE SOUTH FLORIDA ATLANTIC COAST METRO AREAS.
LONG TERM...
FOR SATURDAY THROUGH TUESDAY NIGHT...
THE MODELS BRING A STRONGER UPPER LEVEL LOW TO THE AREA BY
SATURDAY MORNING. THIS MAY BRING INCREASING CHANCES FOR SHOWERS
AND STORMS. HOWEVER, BOTH THE GFS AND THE ECMWF ARE INDICATING
BETTER CHANCES JUST TO THE NORTH IN CENTRAL FLORIDA. GIVEN THIS,
HAVE KEPT POPS AT 50 PERCENT FOR NOW. BY SUNDAY MORNING, THE LOW
WEAKEN CONSIDERABLE AND AN UPPER LEVEL FRONT IS PROGGED TO MOVE
ACROSS SOUTH FLORIDA. THE MODELS ARE IN SOME DISAGREEMENT HOW FAST
IT WILL MOVE THROUGH , WITH THE GFS BEING MORE AGGRESSIVE. THE
ECMWF ACTUALLY LOOKS TO STALL IT OVER THE SOUTHERN PORTION OF THE
CWA ON SUNDAY. EITHER WAY, IT WILL SERVE TO BRING A SOMEWHAT
BETTER CHANCE FOR PRECIP ON SUNDAY. SO HAVE KEPT LIKELY POPS IN
THE FORECAST THAT DAY.
BY THE BEGINNING OF THE WEEK, THE BOUNDARY WILL EITHER BE OUT OF
THE AREA, OR WASHING OUT. HOWEVER, THERE WILL STILL BE A TROUGH
OVER THE EASTERN US, WITH THE BASE IN THE AREA. THIS WILL KEEP
CHANCES OF SHOWERS AND STORMS ELEVATED INTO NEXT WEEK, WITH LIKELY
POPS EACH AFTERNOON THROUGH TUESDAY. THE TROUGH WILL BEGIN TO WEAK
LATE TUESDAY, ALLOWING POPS TO DROP OFF THROUGH THE NIGHT AND INTO
WEDNESDAY MORNING.
AVIATION...
WEAK HIGH PRESSURE ACROSS THE SOUTHEASTERN GULF OF MEXICO WILL
TURN FLOW MORE SOUTHWESTERLY ACROSS SOUTH FLORIDA THROUGH THE DAY.
THIS SHOULD KEEP THE MAJORITY OF THE AFTERNOON CONVECTION ACROSS
THE INTERIOR AND EAST COASTAL AREAS. KEPT SOUTHWEST TO SOUTH-
SOUTHWEST FLOW ACROSS ALL EAST COAST SITES THROUGH THE
AFTERNOON. HOWEVER...ANY EAST COAST SEA BREEZE THAT DEVELOPS
SHOULD NOT PUSH TOO FAR INLAND BUT COULD BRIEFLY AFFECT ANY OF THE
EAST COAST SITES.
MARINE...
HIGH PRESSURE OVER THE GULF IS WEAKENING TODAY AS A WEAK COLD
FRONT SLOWLY PROGRESSES TOWARDS THE REGION. THIS WILL ALLOW FOR
CONTINUED CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH AT LEAST
THE WEEKEND, AS THE FRONT SHOULD STALL BETWEEN CENTRAL FLORIDA AND
LAKE OKEECHOBEE. ALSO, A LONG PERIOD SWELL WILL CONTINUE IN THE
ATLANTIC WATERS FOR AT LEAST THE NEXT COUPLE OF DAYS. THE HIGHEST
SWELL, OF AROUND 3 FEET, WILL BE OFF THE PALM BEACH COUNTY COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 87 74 85 / 50 60 30 60
FORT LAUDERDALE 76 88 77 86 / 50 60 40 70
MIAMI 76 88 76 86 / 50 60 30 60
NAPLES 76 87 75 86 / 40 50 30 70
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH LATE TONIGHT FOR FLZ168.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....55/CWC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS MELBOURNE FL
500 AM EDT WED SEP 17 2014
.DISCUSSION...
CURRENT...
NEARLY SATURATED AIRMASS OVER CENTRAL FL WITH EVENING RAOBS
MEASURING PWAT VALUES BTWN 2.0"-2.2". LATEST RUC ANALYSIS SHOWS A
WELL DEFINED H100-H70 TROF EXTENDING FROM THE NC OUTER BANKS TO THE
NE GOMEX...ASSOCD WITH A STALLED FRONTAL BNDRY OVER THE DEEP SOUTH.
ALOFT...A FEW POCKETS OF NOTEWORTHY MID LVL VORTICITY OVER THE
GOMEX/N FL...UPR LVL DIVERGENCE IS WEAK AS THE CLOSEST H30-H20 JET
STREAK IS LAGGING BACK OVER THE LWR MS VALLEY. MID LVL TEMPS ARE
RUNNING BTWN 7-8C AT H70...AND ARND -7C AT H50...RESULTING IN
UNIMPRESSIVE LAPSE RATES ARND 5.5C/KM.
TODAY-TONIGHT...
A BROAD SFC LOW OVER GA/SC WILL SLOWLY CRANK THE STATIONARY FRONT
INTO CENTRAL FL. PROGRESS WILL BE SLOW...HOWEVER...AS THE JET STREAK
HAS A STRONG ZONAL ORIENTATION THAT PROVIDE LITTLE SWD PUSH. ATLC
RIDGE OVER S FL STRAITS WILL SLOW IT FURTHER...BUT IS QUITE WEAK AND
WILL NOT BE ABLE STOP THE FRONT AS THE LOW LIFTS UP THE ERN SEABOARD.
DEEP MOISTURE COUPLED WITH A THE MID LVL VORTICITY SHOULD ALLOW NMRS
SHRAS AND SCT TSRAS TO DVLP...BUT IT WILL TAKE A WHILE FOR THE LOW
LVL AIRMASS TO DESTABILIZE ENOUGH TO OVERCOME THE WEAK MID LVL LAPSE
RATES. FURTHERMORE...DEEP MOISTURE ALOFT SHOULD PRODUCE MID/UPR LVL
CLOUD DECKS THAT WILL HINDER SFC HEATING. EVEN SO...CANNOT OVERLOOK
SHRA/TSRA ACTIVITY OVER THE ATLC/GOMEX THAT HAS BEEN ONGOING THRU
THE EVENING...ONCE SFC TEMPS REACH THEIR CONVECTIVE TRIGGERS...
PRECIP WILL LIKELY AREAWIDE. OVERALL INSTABILITY LOOKS MODEST AT
BEST...STRONG/SVR TSTM THREAT WILL BE QUITE LOW. SCT SHRAS/TSRAS AFT
SUNSET MAY LINGER INTO EARLY MORNING BUT WILL END AS WINDS VEER TO
THE NW AND PUSH DRIER AND MORE STABLE AIR INTO CENTRAL FL.
CLOUD COVER AND RAIN COOLED AIR WILL KEEP MAX TEMPS NEAR AVG...
GENERALLY IN THE M/U80S. NO MEANINGFUL COLD AIR ADVECTION WILL OCCUR
BEHIND THE FRONT...MIN TEMPS IN THE L/M70S WILL BE SLIGHTLY ABV AVG
DUE TO LINGERING CLOUD COVER.
THU-SAT...
SHORT WAVE ENERGY WILL DIG INTO THE BROAD TROUGH COVERING THE ERN
CONUS AND WRN ATLC...RESULTING IN THE FORMATION OF A CUTOFF LOW
(ALBEIT ELONGATED WITH A POS TILTED AXIS) ACROSS NORTH/CENTRAL FL
AND EXTENDING INTO THE ADJCT ATLC. DEW PT FRONT INITIALLY OVER THE
NORTHERN PENINSULA WILL DRIFT SWD OVER THE REGION AND THEN STALL NEAR
LAKE OKEE AS WEAK LOW PRES WAVE DEVELOPS OFFSHORE THE SERN SEABOARD.
AFTER AN INITIALLY DRIER DAY ON THU...MEAN MOISTURE WILL SHOW SOME
SLIGHT NWD CREEP INTO THE WEEKEND WITH POPS COMING BACK UP TO NEAR
THE CLIMO NORMS (40-50). DEEPEST MOISTURE AND HIGHEST RAIN CHCS WILL
GENERALLY REMAIN CLOSER THE LAKE THROUGH THE PERIOD. TEMPS WILL
TREND SLIGHTLY LOWER ON FRI-SAT COMPARED TO THU OWING TO INCREASING
CLOUD COVER.
SUN-TUE...
THE GFS/ECM MODELS DIFFER SLIGHTLY WITH RESPECT TO THE SPEED IN
WHICH THE (BRIEFLY) CUTOFF LOW OVHD OPENS UP INTO A TROUGH AND
EJECTS NEWD. THE GFS IS FASTER...AND A BIT STRONGER WITH THE
ATTENDANT SFC LOW/WAVE...WHICH DRIES THINGS OUT TO A LITTLE MORE
EXTENT THAN THE ECM SUN. BOTH MODELS SHOW ANOTHER EARLY FALL SEASON
FRONTAL BOUNDARY ENCROACHING UPON THE NORTHERN PENINSULA BY TUE...
POSSIBLY SAGGING SWD INTO THE REGION BY THE MIDDLE OF NEXT WEEK...
BUT TOO EARLY TO SPECULATE AT LENGTH ABOUT ANY SWD PUSH JUST YET.
OVERALL POP TREND WILL BE SLOWLY UPWARD FOR EARLY NEXT WEEK. TEMPS
NOT TOO FAR FROM CLIMO.
&&
.AVIATION...
THRU 17/14Z...PREVAILING VFR ALL SITES WITH W/SW SFC WNDS ARND
5KTS...CIGS AOA FL120...SLGT CHC MVFR SHRAS. BTWN 17/14Z-17/17Z...
SFC WNDS BCMG W BTWN 5-10KTS...PREVAILING CIGS DCRSG TO FL060-080
WITH CHC OF MVFR SHRAS ALL SITES. BTWN 17/17Z-17/24...OCNL WRLY SFC
WND G18KTS...NMRS MVFR SHRAS/SCT IFR TSRAS. BTWN 18/00Z-18/03Z...
SFC WINDS BCMG W/NW AOB 5KTS...SCT MVFR SHRAS/ISOLD IFR TSRAS
ENDING...CIGS AOA FL120.
&&
.MARINE...
TODAY-TONIGHT...
LOW LVL TROF AXIS EXTENDING FROM THE NC OUTER BANKS TO THE NE GOMEX
HAS SUPPRESSED THE ATLC RIDGE AXIS INTO S FL AND THE FL STRAITS.
INTERACTION BTWN THESE TWO WX FEATURES WILL GENERATE A GENTLE TO
MODERATE WRLY BREEZE ACRS THE LCL ATLC THRU THE DAY...BCMG W/NW
OVERNIGHT AS THE TROF AXIS DRIFTS INTO S FL. LATEST OBS FROM BUOY010
SHOW THE MUCH ANTICIPATED SWELL FROM HURRICANE EDOUARD STARTING TO
WORK ITS WAY INTO THE LCL ATLC...THOUGH A BIT SLOWER THAN INDICATED
BY THE WAVE MODELS. SEAS WILL BUILD THRU THE DAY... REACHING 3-4FT
NEARSHORE AND 5-6FT OFFSHORE WITH DOMINANT PDS AOA 13SEC. THIS MAY
CAUSE VERY ROUGH CONDITIONS NEAR THE MOUTHS OF INLETS DURING THE
OUTGOING MORNING TIDE.
RIP CURRENTS: LONG PERIOD SWELLS WILL START TO AFFECT THE COAST WED
MORNING...RESULTING IN DANGEROUS SURF CONDITIONS AND A HIGH RISK OF
DANGEROUS RIP CURRENTS.
THU-SUN...
ANY RESIDUAL SWELL FROM EDOUARD WILL BE WANING THU...WITH MINIMAL
WIND CHOP INDICATED INTO THIS WEEKEND. WINDS GENERALLY BELOW 15KT
WITH SEAS MOSTLY IN THE 2-3FT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 87 73 89 73 / 60 30 20 10
MCO 90 73 92 72 / 60 30 20 10
MLB 89 73 87 75 / 60 40 20 10
VRB 89 72 89 73 / 60 40 20 10
LEE 89 73 93 74 / 60 30 20 10
SFB 90 73 92 75 / 60 30 20 10
ORL 90 73 91 75 / 60 30 20 10
FPR 88 72 89 72 / 60 40 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....CRISTALDI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 AM EDT WED SEP 17 2014
.DISCUSSION...
CURRENT...
NEARLY SATURATED AIRMASS OVER CENTRAL FL WITH EVENING RAOBS
MEASURING PWAT VALUES BTWN 2.0"-2.2". LATEST RUC ANALYSIS SHOWS A
WELL DEFINED H100-H70 TROF EXTENDING FROM THE NC OUTER BANKS TO THE
NE GOMEX...ASSOCD WITH A STALLED FRONTAL BNDRY OVER THE DEEP SOUTH.
ALOFT...A FEW POCKETS OF NOTEWORTHY MID LVL VORTICITY OVER THE
GOMEX/N FL...UPR LVL DIVERGENCE IS WEAK AS THE CLOSEST H30-H20 JET
STREAK IS LAGGING BACK OVER THE LWR MS VALLEY. MID LVL TEMPS ARE
RUNNING BTWN 7-8C AT H70...AND ARND -7C AT H50...RESULTING IN
UNIMPRESSIVE LAPSE RATES ARND 5.5C/KM.
TODAY-TONIGHT...
A BROAD SFC LOW OVER GA/SC WILL SLOWLY CRANK THE STATIONARY FRONT
INTO CENTRAL FL. PROGRESS WILL BE SLOW...HOWEVER...AS THE JET STREAK
HAS A STRONG ZONAL ORIENTATION THAT PROVIDE LITTLE SWD PUSH. ATLC
RIDGE OVER S FL STRAITS WILL SLOW IT FURTHER...BUT IS QUITE WEAK AND
WILL NOT BE ABLE STOP THE FRONT AS THE LOW LIFTS UP THE ERN SEABOARD.
DEEP MOISTURE COUPLED WITH A THE MID LVL VORTICITY SHOULD ALLOW NMRS
SHRAS AND SCT TSRAS TO DVLP...BUT IT WILL TAKE A WHILE FOR THE LOW
LVL AIRMASS TO DESTABILIZE ENOUGH TO OVERCOME THE WEAK MID LVL LAPSE
RATES. FURTHERMORE...DEEP MOISTURE ALOFT SHOULD PRODUCE MID/UPR LVL
CLOUD DECKS THAT WILL HINDER SFC HEATING. EVEN SO...CANNOT OVERLOOK
SHRA/TSRA ACTIVITY OVER THE ATLC/GOMEX THAT HAS BEEN ONGOING THRU
THE EVENING...ONCE SFC TEMPS REACH THEIR CONVECTIVE TRIGGERS...
PRECIP WILL LIKELY AREAWIDE. OVERALL INSTABILITY LOOKS MODEST AT
BEST...STRONG/SVR TSTM THREAT WILL BE QUITE LOW. SCT SHRAS/TSRAS AFT
SUNSET MAY LINGER INTO EARLY MORNING BUT WILL END AS WINDS VEER TO
THE NW AND PUSH DRIER AND MORE STABLE AIR INTO CENTRAL FL.
CLOUD COVER AND RAIN COOLED AIR WILL KEEP MAX TEMPS NEAR AVG...
GENERALLY IN THE M/U80S. NO MEANINGFUL COLD AIR ADVECTION WILL OCCUR
BEHIND THE FRONT...MIN TEMPS IN THE L/M70S WILL BE SLIGHTLY ABV AVG
DUE TO LINGERING CLOUD COVER.
THU-SAT...
SHORT WAVE ENERGY WILL DIG INTO THE BROAD TROUGH COVERING THE ERN
CONUS AND WRN ATLC...RESULTING IN THE FORMATION OF A CUTOFF LOW
(ALBEIT ELONGATED WITH A POS TILTED AXIS) ACROSS NORTH/CENTRAL FL
AND EXTENDING INTO THE ADJCT ATLC. DEW PT FRONT INITIALLY OVER THE
NORTHERN PENINSULA WILL DRIFT SWD OVER THE REGION AND THEN STALL NEAR
LAKE OKEE AS WEAK LOW PRES WAVE DEVELOPS OFFSHORE THE SERN SEABOARD.
AFTER AN INITIALLY DRIER DAY ON THU...MEAN MOISTURE WILL SHOW SOME
SLIGHT NWD CREEP INTO THE WEEKEND WITH POPS COMING BACK UP TO NEAR
THE CLIMO NORMS (40-50). DEEPEST MOISTURE AND HIGHEST RAIN CHCS WILL
GENERALLY REMAIN CLOSER THE LAKE THROUGH THE PERIOD. TEMPS WILL
TREND SLIGHTLY LOWER ON FRI-SAT COMPARED TO THU OWING TO INCREASING
CLOUD COVER.
SUN-TUE...
THE GFS/ECM MODELS DIFFER SLIGHTLY WITH RESPECT TO THE SPEED IN
WHICH THE (BRIEFLY) CUTOFF LOW OVHD OPENS UP INTO A TROUGH AND
EJECTS NEWD. THE GFS IS FASTER...AND A BIT STRONGER WITH THE
ATTENDANT SFC LOW/WAVE...WHICH DRIES THINGS OUT TO A LITTLE MORE
EXTENT THAN THE ECM SUN. BOTH MODELS SHOW ANOTHER EARLY FALL SEASON
FRONTAL BOUNDARY ENCROACHING UPON THE NORTHERN PENINSULA BY TUE...
POSSIBLY SAGGING SWD INTO THE REGION BY THE MIDDLE OF NEXT WEEK...
BUT TOO EARLY TO SPECULATE AT LENGTH ABOUT ANY SWD PUSH JUST YET.
OVERALL POP TREND WILL BE SLOWLY UPWARD FOR EARLY NEXT WEEK. TEMPS
NOT TOO FAR FROM CLIMO.
&&
.AVIATION...
THRU 17/14Z...VFR ALL SITES WITH W/SW SFC WNDS ARND 5KTS...CIGS AOA
FL120...SLGT CHC MVFR SHRAS W OF KLEE-KOBE. BTWN 17/14Z-17/17Z...SFC
WNDS BCMG W BTWN 5-10KTS...PREVAILING CIGS DCRSG TO FL060-080 WITH
CHC OF MVFR SHRAS ALL SITES. BTWN 17/17Z-17/24...OCNL WRLY SFC WND
G18KTS...NMRS MVFR SHRAS/SCT IFR TSRAS. AFT 18/00Z...
&&
.MARINE...
TODAY-TONIGHT...
LOW LVL TROF AXIS EXTENDING FROM THE NC OUTER BANKS TO THE NE GOMEX
HAS SUPPRESSED THE ATLC RIDGE AXIS INTO S FL AND THE FL STRAITS.
INTERACTION BTWN THESE TWO WX FEATURES WILL GENERATE A GENTLE TO
MODERATE WRLY BREEZE ACRS THE LCL ATLC THRU THE DAY...BCMG W/NW
OVERNIGHT AS THE TROF AXIS DRIFTS INTO S FL. LATEST OBS FROM BUOY010
SHOW THE MUCH ANTICIPATED SWELL FROM HURRICANE EDOUARD STARTING TO
WORK ITS WAY INTO THE LCL ATLC...THOUGH A BIT SLOWER THAN INDICATED
BY THE WAVE MODELS. SEAS WILL BUILD THRU THE DAY... REACHING 3-4FT
NEARSHORE AND 5-6FT OFFSHORE WITH DOMINANT PDS AOA 13SEC. THIS MAY
CAUSE VERY ROUGH CONDITIONS NEAR THE MOUTHS OF INLETS DURING THE
OUTGOING MORNING TIDE.
RIP CURRENTS: LONG PERIOD SWELLS WILL START TO AFFECT THE COAST WED
MORNING...RESULTING IN DANGEROUS SURF CONDITIONS AND A HIGH RISK OF
DANGEROUS RIP CURRENTS.
THU-SUN...
ANY RESIDUAL SWELL FROM EDOUARD WILL BE WANING THU...WITH MINIMAL
WIND CHOP INDICATED INTO THIS WEEKEND. WINDS GENERALLY BELOW 15KT
WITH SEAS MOSTLY IN THE 2-3FT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 87 73 89 73 / 60 30 20 10
MCO 90 73 92 72 / 60 30 20 10
MLB 89 73 87 75 / 60 40 20 10
VRB 89 72 89 73 / 60 40 20 10
LEE 89 73 93 74 / 60 30 20 10
SFB 90 73 92 75 / 60 30 20 10
ORL 90 73 91 75 / 60 30 20 10
FPR 88 72 89 72 / 60 40 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....CRISTALDI
AREA FORECAST DISCUSSION
NWS TOPEKA KS
346 PM CDT Wed Sep 17 2014
.SHORT TERM...(This Evening through Thursday)
Issued at 346 PM CDT WED SEP 17 2014
20 water vapor imagery shows mid level ridging over the Rockies with
the remnants of Odile moving across northern Mexico underneath the
ridge. Northwest flow persists across the central plains and a
shortwave was noted over the MT/ND boarder with another disturbance
coming across southeast WY. At the surface, a frontal boundary
remains just to the south and west of the forecast area with
easterly low level flow helping low clouds to hold strong. Where the
clouds have persisted, temps remain in the mid 70s.
For tonight model progs show some fairly dry air in the 900MB to
700MB layer over eastern KS through the night and that the better
isentropic assent combined with saturation is likely to be across
central KS where the surface boundary is located. However the
persistence of the stratus brings into question whether the models
are handling the low level moisture profile very well. Additionally
the models want to shear out the vort max that is currently
producing some lightning strikes in southeastern WY. The forecast
anticipates the better chances for elevated precip to be mainly
along the southwestern boarder where stronger low level
baroclinicity exists and where some mid level saturation is
indicated on the isentropic surfaces. However there is some doubt
especially if the disturbance coming from WY remains better defined
overnight. Mid level lapse rates are forecast to be steep enough
that some of the storms may produce some small hail over night if
they area able to develop.
Late tonight the models want to develop some dense fog overnight
with temp dewpoint spreads approaching zero. It does not look like a
classic radiational fog set up with an easterly wind persisting
through the night. In fact models show 925MB winds of 15KT or better
through the night helping to keep some mixing of the boundary layer.
If in fact there is dry air just above the surface, it is hard to
imagine a lot of fog forming. Add on the chance for some mid level
clouds and I don`t have the confidence to go with anything but
patchy fog across the northern counties where is has clear out
already. Lows tonight should fall into the lower and middle 60s for
most locations.
Thinking that fog and stratus will not be a major issue overnight,
have a forecast for Thursday with decreasing POPs and skies becoming
partly cloudy. Of course if widespread fog develops, the temp
forecast and decreasing clouds may be a little optimistic. For now
with some insolation anticipated and mixing to around 900MB, highs
are expected to be in the mid 70s to lower 80s. This is slightly
cooler from todays original forecast as models show some weak cold
air advection and cooler temps at 925MB for Thursday.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 346 PM CDT WED SEP 17 2014
First few periods of this portion of the forecast still looking dry
for the most part. Still have minor potential for more elevated
convection Thursday night, mainly in northeastern locations, as
isentropic lift picks up on increasing low level jet. Moisture
availability looks meager by this point so have kept a mention out,
but could see an isolated storm or two in the late evening and early
morning hours. Deeper mixing and good insolation expected for the
bulk of Friday for highs approaching 90.
Cold front continues on its slightly slower track with its upper
trough even weaker keeping forcing with the front meager.
Operational models and most GFS ensemble members keep the remnants
of Odile in southern Kansas with again some concern for weaker
forcing/subsidence just to its north. Given these concerns have
lowered PoPs and raised highs a bit area-wide. With upper flow
weakening could see lingering precip in southern areas into Sunday
as well. Models in fairly good agreement in cut-off upper trough
over the southwest states making east to northeast progress into the
Plains toward the mid-week. Have much uncertainty in timing and lift
potential with this and have kept chances small. As Canadian high
pressure builds southeast into the Mississippi Valley, temps are
expected to be somewhat below normal for Monday into Wednesday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1226 PM CDT WED SEP 17 2014
The terminals are expected to remain within a northeast to
easterly low level flow through the period with little or no dry
air advection at the surface. Confidence in when the stratus will
burn off is marginal, but there are signs from satellite and
recent obs that it is starting to erode. Initially based the timing
of improvements to CIGS on the RAP forecast soundings but adjusted
them to hold onto the CIGS slightly longer since there seems to be
a expansive deck of clouds still to the east and northeast.
Models have backed off on elevated precip overnight. Think this
may be due to some dry air in the 900MB to 700MB layer seen in the
isentropic surfaces. With models shearing out the upstream
vorticity or keeping the vort max to the northeast of the
terminals, think it is more likely to remain dry overnight at the
terminals and will not insert a mention of precip at this time.
MOS guidance also wants to redevelop fog (possibly dense) for
Thursday morning. However forecast soundings from the RAP and NAM
suggest any moisture will be very shallow and that 925MB winds of
15 to 20KT should keep some dry air mixing into the boundary layer
through the night. Additionally models show some possible mid
level clouds moving overhead limiting the radiational effects for
ground fog. Because of this, I`m not ready to put IFR VSBY in the
forecast.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
200 PM MDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 143 PM MDT WED SEP 17 2014
WEAK CONVECTION CURRENTLY DEVELOPING IN EASTERN COLORADO ALONG
PALMER DIVIDE AND WEAK WIND CONVERGENT ZONE WILL MOVE INTO
WESTERN KANSAS THIS AFTERNOON. INITIALLY HIGHER BASED CONVECTION
IN KIT CARSON COUNTY WHERE DEWPOINTS ARE IN THE UPPER 30S SHOULD
EVENTUALLY REACH BETTER MOISTURE AS IT WORKS EAST WHERE DEWPOINTS
ARE IN THE LOW-MID 50S. HRRR RUNS ALL MORNING HAVE CONTINUED TO
INDICATE THE POTENTIAL FOR SCATTERED SHRA/TSRA MAINLY SOUTH OF
I-70 IN KANSAS UNTIL EARLY EVENING. NAM HINTS AT THIS AS WELL.
BOTTOM LINE...HAVE INCLUDED LOW POPS TO ACCOUNT FOR THIS BUT FORCING
APPEARS WEAK AND SOME CINH REMAINS TO BE OVERCOME. OVERALL NOT
EXPECTING A BIG CONVECTIVE EVENT HERE.
WIDESPREAD STRATUS AND LOCALLY DENSE FOG IS LIKELY TO DEVELOP OVER
THE EASTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. SURFACE
DEWPOINTS WILL HOLD IN THE UPPER 50S AND LOWER 60S WITH CONTINUED
LIGHT SOUTHEAST BOUNDARY LAYER FLOW.
POTENTIAL EXISTS FOR OVERNIGHT CONVECTION...MAINLY AFTER MIDNIGHT...
EAST OF A TRENTON NEBRASKA TO HOXIE KANSAS LINE. GFS/NAM GUIDANCE
BOTH GIVE SUPPORT TO A SSE-NNW ORIENTED BAND OF SHOWERS AND
THUNDERSTORMS...ALTHOUGH TIMING AND PLACEMENT DIFFERS SOMEWHAT
BETWEEN MODELS. 500-1000 J/KG OF ELEVATED CAPE IS PRESENT TO
SUPPORT CONVECTION IF INHIBITION IS OVERCOME.
TEMPERATURES SHOULD CHANGE LITTLE NEXT COUPLE DAYS AS UPPER RIDGE
OVER THE ROCKIES SHIFTS EAST TO THE CENTRAL HIGH PLAINS. HIGHS
THURSDAY WILL AGAIN BE ABOVE NORMAL AROUND 90F GIVEN FORECAST 850
MB TEMPS 26-30C.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED SEP 17 2014
THURSDAY NIGHT-SATURDAY...FOCUS FOR THIS PORTION OF THE FORECAST IS
THE TRACK OF WHATS NOW WEAKENING TROPICAL STORM ODILE.
DEEP MOISTURE (WITH PRECIPTABLE WATER VALUES AROUND 1.5 INCHES)
ASSOCIATED WITH THE REMNANTS OF THIS SYSTEM ARE FORECAST TO REACH
AREAS SOUTH OF INTERSTATE 70 LATE FRIDAY AFTERNOON...SLIDING SLOWLY
EAST FRIDAY NIGHT AND OUT OF THE AREA EARLY SATURDAY MORNING. THE
GFS IS SLIGHTLY FURTHER SOUTH WITH THE PLUME OF MOISTURE COMPARED TO
THE 12Z NAM/00Z ECMWF...SO NO SLAM DUNK ON PRECIPITATION AMOUNTS
WITH THIS SYSTEM NOR HOW HIGH TO GO WITH POPS. IT APPEARS THAT
EITHER WAY...AS MENTIONED ABOVE...HIGHEST POPS WILL BE ALONG OR
SOUTH OF THE INTERSTATE. SOME LOCALLY HEAVY RAINFALL IS POSSIBLE IF
THE FURTHER NORTH NAM/ECMWF VERIFY.
SOUTH TO SOUTHWEST WINDS FRIDAY MID MORNING THROUGH AFTERNOON
GUSTING IN THE 25-35 MPH RANGE.
FOR SATURDAY AFTERNOON SOME MOISTURE MOVES IN FROM THE NORTHWEST
ASSOCIATED WITH AN UPPER TROUGH PASSAGE. CANT RULE OUT A FEW SHOWERS
AND MAYBE A THUNDERSTORM WITH IT WITH SLIGHT CHANCE POPS AT BEST.
SATURDAY NIGHT...DRY WITH MAYBE SOME HIGH CLOUDS MOVING IN FROM THE
WEST/SOUTHWEST.
LOWS THURSDAY NIGHT MID 50S TO MID 60S WITH SIMILAR...MAYBE A TAD
COOLER READINGS FRIDAY NIGHT.
HIGHS FRIDAY IN THE 80S WITH UPPER 70S TO LOW 80S SATURDAY.
SUNDAY-SUNDAY NIGHT...DRY WEATHER EXPECTED. MID AND HIGH CLOUDS
INCREASE FROM THE SOUTHWEST...ESPECIALLY LATE IN THE AFTERNOON
THROUGH THE NIGHT...AHEAD OF AN UPPER LEVEL LOW PRESSURE AREA MOVING
NORTHEAST TOWARD THE SLC AREA. HIGHS IN THE MID TO UPPER 70S WITH
LOWS IN THE LOW TO MID 50S. WILL BE INTRODUCING SOME SLIGHT CHANCE
TO LOW CHANCE POPS FOR SHOWERS/ISOLATED THUNDERSTORMS FOR THE
WESTERN 1/2 OF THE AREA. HIGH TEMPERATURES MID 70S TO AROUND 80 WITH
LOWS IN THE LOW TO MID 50S.
MONDAY-MONDAY NIGHT...SCATTERED TO BROKEN CLOUDINESS CONTINUES AS
THE UPPER LOW AND ASSOCIATED TROUGH LIFTS NORTHEAST TOWARD EASTERN
WYOMING. WILL NEED TO MAINTAIN SOME LOW CHANCES FOR
SHOWERS/THUNDERSTORMS. HIGHS IN THE LOW TO MID 70S WITH LOWS IN THE
LOW TO MID 50S.
TUESDAY-WEDNESDAY...UPPER LOW AND ASSOCIATED TROUGH FORECAST TO MOVE
EAST/SOUTHEAST TOWARD NORTHEAST NEBRASKA BY THE END OF THE PERIOD.
CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY SLOWLY DECREASING IN
COVERAGE FROM WEST TO EAST WEDNESDAY AS MOISTURE DECREASES FROM WEST
TO EAST WITH PASSAGE OF UPPER TROUGH. HIGHS TUESDAY IN THE LOW 70S
WITH LOW TO MID 70S WEDNESDAY. LOWS TUESDAY NIGHT IN THE LOW TO MID
50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1220 PM MDT WED SEP 17 2014
VFR THROUGH THE TAF PERIOD AT KGLD. SCATTERED CONVECTION IS
EXPECTED TO DEVELOP OVER EASTERN COLORADO EARLY THIS AFTERNOON AND
MOVE INTO WESTERN KANSAS. AT THIS TIME...THE PRECIP IS NOT
EXPECTED TO HAVE AN IMPACT ON THE TERMINAL AREA DUE TO LIMITED
COVERAGE.
MOIST LOW LEVEL FLOW WITH DEWPOINTS IN THE LOWER 60S CONTINUES
ACROSS THE KMCK AREA. IFR/LIFR CONDITIONS IN STRATUS AND DENSE FOG
EXPECTED TO DEVELOP AT KMCK AFTER AROUND 08Z AND CONTINUE THROUGH
MID-MORNING THURSDAY. SCATTERED TO BROKEN CONVECTION IS ALSO
POSSIBLE OVERNIGHT ACROSS PARTS OF NC KANSAS INTO SW NEBRASKA. SOME
UNCERTAINTY STILL EXISTS AS TO LOCATION AND IMPACT ON KMCK
TERMINAL WITH BETTER COVERAGE SEEN FURTHER EAST. CONVECTION WOULD
MOST LIKELY OCCUR IN THE 06-12Z TIME FRAME IF IT DOES DEVELOP NEAR
THE TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...99
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
143 PM MDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 143 PM MDT WED SEP 17 2014
WEAK CONVECTION CURRENTLY DEVELOPING IN EASTERN COLORADO ALONG
PALMER DIVIDE AND WEAK WIND CONVERGENT ZONE WILL MOVE INTO
WESTERN KANSAS THIS AFTERNOON. INITIALLY HIGHER BASED CONVECTION
IN KIT CARSON COUNTY WHERE DEWPOINTS ARE IN THE UPPER 30S SHOULD
EVENTUALLY REACH BETTER MOISTURE AS IT WORKS EAST WHERE DEWPOINTS
ARE IN THE LOW-MID 50S. HRRR RUNS ALL MORNING HAVE CONTINUED TO
INDICATE THE POTENTIAL FOR SCATTERED SHRA/TSRA MAINLY SOUTH OF
I-70 IN KANSAS UNTIL EARLY EVENING. NAM HINTS AT THIS AS WELL.
BOTTOM LINE...HAVE INCLUDED LOW POPS TO ACCOUNT FOR THIS BUT FORCING
APPEARS WEAK AND SOME CINH REMAINS TO BE OVERCOME. OVERALL NOT
EXPECTING A BIG CONVECTIVE EVENT HERE.
WIDESPREAD STRATUS AND LOCALLY DENSE FOG IS LIKELY TO DEVELOP OVER
THE EASTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. SURFACE
DEWPOINTS WILL HOLD IN THE UPPER 50S AND LOWER 60S WITH CONTINUED
LIGHT SOUTHEAST BOUNDARY LAYER FLOW.
POTENTIAL EXISTS FOR OVERNIGHT CONVECTION...MAINLY AFTER MIDNIGHT...
EAST OF A TRENTON NEBRASKA TO HOXIE KANSAS LINE. GFS/NAM GUIDANCE
BOTH GIVE SUPPORT TO A SSE-NNW ORIENTED BAND OF SHOWERS AND
THUNDERSTORMS...ALTHOUGH TIMING AND PLACEMENT DIFFERS SOMEWHAT
BETWEEN MODELS. 500-1000 J/KG OF ELEVATED CAPE IS PRESENT TO
SUPPORT CONVECTION IF INHIBITION IS OVERCOME.
TEMPERATURES SHOULD CHANGE LITTLE NEXT COUPLE DAYS AS UPPER RIDGE
OVER THE ROCKIES SHIFTS EAST TO THE CENTRAL HIGH PLAINS. HIGHS
THURSDAY WILL AGAIN BE ABOVE NORMAL AROUND 90F GIVEN FORECAST 850
MB TEMPS 26-30C.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 250 AM MDT WED SEP 17 2014
GOING INTO THURSDAY MORNING THERE WILL BE SOME REMNANTS SHOWERS
AND FOG ASSOCIATED WITH TROUGH PUSHING EAST OUT OF THE REGION.
UPPER RIDGE THEN SETTLES OVER THE CENTRAL PORTIONS OF THE COUNTRY
CONTINUING THE WARM TREND WITH ABOVE NORMAL TEMPS RIGHT INTO
FRIDAY NIGHT. THE REST OF THURSDAY AFTER PRECIP/CLDS CLR REGION
WILL BE DECENT SUMMER-LIKE DAY...AND TRANSLATE INTO A WARM
OVERNIGHT PERIOD AS SFC RIDGE REMAINS MAIN WX FEATURE. FOR FRIDAY
AND FRIDAY NIGHT...MODELS DO SHOW THE REMNANTS OF ODILE PASSING
JUST TO OUR SOUTH AND AN UPPER LEVEL TROUGH TO OUR NORTH. THE
COMBINATION OF THESE TWO SYSTEMS WILL BRING A CHANCE FOR RW/TRW TO
THE AREA. BEST CHANCES FOR PRECIP WILL BE IN EASTERN/SOUTHERN
ZONES CLOSEST TO ODILE REMNANTS...DUE TO ABUNDANT TROPICAL
MOISTURE IN PLACE. OVERNIGHT LOWS WILL RANGE FROM THE MID 50S INTO
THE MID 60S...WARMEST EAST.
ON SATURDAY...THE UPPER TROUGH WILL MOVE EAST TOWARD THE GREAT LAKES
WITH RISING HEIGHTS OVER THE CENTRAL HIGH PLAINS. SHORTWAVE RIDGING
BETWEEN THE AFOREMENTIONED TROUGH AND A CLOSED UPPER LOW IN THE WEST
WILL RESULT IN DRY WEATHER LATE SATURDAY THROUGH MONDAY. UNCERTAINTY
IS RATHER HIGH TOWARD THE END OF THE EXTENDED GIVEN DISCREPANCIES
WITHIN MEDIUM RANGE GUIDANCE. GFS TRANSITIONS TO AN OPEN WAVE AND
MOVES THE SYSTEM ALONG FASTER THAN THE ECMWF...ALTHOUGH THE LATEST
RUN OF THE ECMWF HAS TRENDED TOWARD THE MORE PROGRESSIVE GFS. HAVE
MAINTAINED LOW POPS ON TUESDAY BUT THE TYPICAL LOW PREDICTABILITY
WITH THESE TYPE SYSTEMS THIS FAR OUT MEANS THAT ADJUSTMENTS WILL MAY
BE NEEDED. ANOTHER DIFFERENCE IS THAT ECMWF IS MORE AGGRESSIVE WITH
A COLD FRONT/SURGE ASSOCIATED WITH ANOTHER UPPER TROUGH MOVING
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY.
HAVE TRENDED TEMPERATURES FOR BOTH MONDAY AND TUESDAY DOWN CLOSER TO
THE CONSENSUS OF THE LATEST RUNS TO ACCOUNT FOR THIS. LOW LEVEL
MOISTURE/WARMTH LOOKS TO BE INSUFFICIENT FOR MEANINGFUL INSTABILITY
TOWARD TUESDAY SO KEPT THUNDER OUT OF THE GRIDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1220 PM MDT WED SEP 17 2014
VFR THROUGH THE TAF PERIOD AT KGLD. SCATTERED CONVECTION IS
EXPECTED TO DEVELOP OVER EASTERN COLORADO EARLY THIS AFTERNOON AND
MOVE INTO WESTERN KANSAS. AT THIS TIME...THE PRECIP IS NOT
EXPECTED TO HAVE AN IMPACT ON THE TERMINAL AREA DUE TO LIMITED
COVERAGE.
MOIST LOW LEVEL FLOW WITH DEWPOINTS IN THE LOWER 60S CONTINUES
ACROSS THE KMCK AREA. IFR/LIFR CONDITIONS IN STRATUS AND DENSE FOG
EXPECTED TO DEVELOP AT KMCK AFTER AROUND 08Z AND CONTINUE THROUGH
MID-MORNING THURSDAY. SCATTERED TO BROKEN CONVECTION IS ALSO
POSSIBLE OVERNIGHT ACROSS PARTS OF NC KANSAS INTO SW NEBRASKA. SOME
UNCERTAINTY STILL EXISTS AS TO LOCATION AND IMPACT ON KMCK
TERMINAL WITH BETTER COVERAGE SEEN FURTHER EAST. CONVECTION WOULD
MOST LIKELY OCCUR IN THE 06-12Z TIME FRAME IF IT DOES DEVELOP NEAR
THE TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...JN/BRB
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1226 PM CDT Wed Sep 17 2014
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 323 AM CDT WED SEP 17 2014
The low level jet has becomes focused directly over the forecast
area and showers/storms are now developing in response to the
isentropic lift. The instability above this lift is around 1000 j/kg
with effective bulk shear near 40 kt. Given the environment can not
rule out a storm capable of producing hail likely under quarter
sized. Expect this activity to increase in coverage as it moves
eastward the next few hours. The low level jet will continue to veer
as it noses more into western MO and isentropic lift becomes better
focused there. A majority of this morning activity should stay
mainly south of interstate 70, and clear out of the area around
sunrise or shortly after. Short term models are suggesting a
potential for fog centered around sunrise especially in north
central KS. Soundings show that any fog and low level stratus will
begin to lift and scatter out from west to east. There are some
indications that the stratus could hold on longer in spots across
east central KS into the afternoon hours. By the afternoon a warm
front should be located from near Salina to Emporia or just south of
there. This is where the cap is weak and surface convergence is
present. The only limiting factor will be no mid/upper level support
to enhance the lift. With steep mid level lapse rates in place the
surface based cape will approach 3500 j/kg. Hodographs will also be
impressive with decent turning with height within the northwest flow
aloft and southerly surface flow. Deep layer shear of 35 to 40 kt
means any storm that is able to develop near the front could quickly
become strong to severe around the 21-01Z time frame. Have kept
slight chances along the southern border of the forecast area
through the evening hours. Further north of the front stratus tries
to linger as a fairly strong cap remains in place so do not expect
any development in those areas. Later in the evening the front
retreats south of the area and southerly flow increases over the
stable air mass. Elevated convection will again be possible, which
should hold off until around 03-06Z. This mornings temperatures will
remain steady with the expansive cloud cover. Highs today should
reach the mid to upper 80s in central KS, and low 80s in northeast
KS if the clouds lift as forecasted.
.LONG TERM...(Thursday through Tuesday)
Issued at 323 AM CDT WED SEP 17 2014
Thursday, scattered to isolated elevated thunderstorms will be
ongoing into the morning hours across the eastern and southern
counties of the the CWA. An upper level ridge across the high plains
will amplify through day. A stronger EML will overspread the area by
Thursday afternoon and the elevated thunderstorms across the
southeast counties should dissipate. Skies will begin to clear from
west to east across the CWA during the afternoon hours. Highs will
vary dependent on afternoon insolation. The southwest counties will
warm into the mid 80s while the eastern counties may keep cloud
cover longer through the afternoon hours and only see highs in the
upper 70s.
Thursday night through Friday night, The upper level ridge axis will
shift east across the central and southern plains into to the the
mid and lower MS river valley by Friday night. The remnants of Odile
will lift northeast around the upper ridge axis across NM into
western KS Friday night. Rain and thunderstorms will slowly spread
northeast across western KS through the night but remain west of the
CWA. Friday highs will be warm with the upper level ridge across the
southern and central plains. Highs Friday afternoon will reach the
mid to upper 80s and it will feel more humid with deeper gulf
moisture in place.
Saturday into Saturday Night, The remnants of Odile will begin to
phase with an upper level trough digging southeast across the
northern plains and upper Midwest. Rain and thunderstorm chances
will increase from west to east across the CWA during the day on
Saturday. The 6Z run of the ECMWF is slower and would bring the
heaviest rain across the CWA Saturday night. The GFS and GEM models
are more progressive in the speed of the upper trough digging
southeast across the northern plains into the upper Midwest. Both
models show the remnants of Odile remaining south of the CWA across
OK and southern KS. ATTM, I`m leaning more towards the ECMWF which
will phase the remnants of Odile with the the northern plains H5
trough during the late afternoon hours across central KS then move
both systems east-southeast across eastern KS during the evening
hours. The ECMWF forecast QPF of 1 to 3 inches rainfall Saturday
into Sunday along and south of I-70, with only a quarter inch of
QPF along the NE border. The other operational models keep the
heavier rainfall south of the CWA with half inch of QPF south of
I-70 and only about a tenth of an inch of rainfall across the
northern counties of the CWA.
Sunday Afternoon through Tuesday, If the 6Z ECMWF solution verifies
the rain and thunderstorms may continue through the morning hours
of Sunday but should end by Sunday afternoon. It looks dry into
early next week, as the H5 trough across the upper Midwest digs
southeast into the Great Lakes and amplifies. The coldest airmass
will remain east of the CWA. Highs will generally be in the mid to
upper 70s with overnight lows in the 50s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1226 PM CDT WED SEP 17 2014
The terminals are expected to remain within a northeast to
easterly low level flow through the period with little or no dry
air advection at the surface. Confidence in when the stratus will
burn off is marginal, but there are signs from satellite and
recent obs that it is starting to erode. Initally based the timing
of improvements to CIGS on the RAP forecast soundings but adjusted
them to hold onto the CIGS slightly longer since there seems to be
a expansive deck of clouds still to the east and northeast.
Models have backed off on elevated precip overnight. Think this
may be due to some dry air in the 900MB to 700MB layer seen in the
isentropic surfaces. With models shearing out the upstream
vorticity or keeping the vort max to the northeast of the
terminals, think it is more likely to remain dry overnight at the
terminals and will not insert a mention of precip at this time.
MOS guidance also wants to redevelop fog (possibly dense) for
Thursday morning. However forecast soundings from the RAP and NAM
suggest any moisture will be very shallow and that 925MB winds of
15 to 20KT should keep some dry air mixing into the boundary layer
through the night. Additionally models show some possible mid
level clouds moving overhead limiting the radiational effects for
ground fog. Because of this, I`m not ready to put IFR VSBY in the
forecast.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Gargan
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1158 PM MDT TUE SEP 16 2014
.UPDATE...
ISSUED AT 823 PM MDT TUE SEP 16 2014
BASED ON LATEST MODEL DATA AND SINCE THERE HAS NOT BEEN ANY FOG
DEVELOPMENT OVER THE LAST 3 MORNINGS WHEN MODELS WERE FORECASTING
FOG...HAVE CUT BACK ON THE AREA/COVERAGE OF FOG FOR THE
OVERNIGHT/MORNING HOURS. DID KEEP A MENTION OF FOG IN THE FORECAST
WHERE THE SREF HAS ATLEAST 50 PERCENT CONFIDENCE OF LESS THAN
A MILE VISIBILITY. AM NOT TOO CONCERNED AT THIS TIME ABOUT
REDUCED VISIBILITIES IF FOG DOES DEVELOP...BUT WILL SEE HOW THE
NIGHT GOES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 147 PM MDT TUE SEP 16 2014
AS OF 2 PM CDT...1 PM MDT...SKIES ACROSS THE TRI-STATE AREA WITH THE
REMAINING EXCEPTION OF ERODING STRATUS EAST OF A MCCOOK NEBRASKA TO
GOVE KANSAS LINE. TEMPERATURES WERE IN THE MID 70S TO MID 80S WHERE
SKIES HAVE CLEARED AND IN THE UPPER 60S TO LOW 70S WHERE STRATUS
REMAINS. WINDS WERE FROM THE SOUTH TO SOUTHWEST AT 10 TO 15 MPH...
GUSTING AS HIGH AS 25 MPH. A LEE TROUGH WAS LOCATED OVER NORTHEAST
COLORADO...SLOWLY PROGRESSING EAST INTO SOUTHWEST NEBRASKA. NO
SIGNIFICANT WEATHER DISTURBANCES WERE NOTED MOVING TOWARDS THE TRI-
STATE AREA.
FOR TONIGHT INTO TOMORROW...MAIN FORECAST CONCERN IS THE CHANCE FOR
FOG LATE TONIGHT/EARLY WEDNESDAY MORNING. BASED ON THE ANTICIPATED
LOCATION OF THE LEE TROUGH...POOLING MOISTURE EAST OF THE TROUGH AND
LIGHT/CALM WINDS...LIMITED THE POTENTIAL FOG TO PORTIONS OF
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. THE BEST CHANCES FOR FOG
SHOULD RESIDE NORTH AND EAST OF A LINE FROM STRATTON NEBRASKA TO
HOXIE TO HILL CITY KANSAS. IT IS INTERESTING TO NOTE THAT THE
NAM...WRF NMM...AND THE RUC13 INDICATE A POTENTIAL FOR DENSE FOG.
FUTURE SHIFTS WILL NEED TO MONITOR THIS THREAT BUT FOR NOW...DID NOT
PLACE DENSE WORDING INTO THE GRIDS.
FOR TOMORROW...WARMER WEATHER IS ANTICIPATED REGION-WIDE AS MOST OF
THE AREA SHOULD REMAIN FREE OF CLOUD COVER AND LOCATIONS THAT
EXPERIENCE FOG SHOULD SEE FOG LIFT AND DISSIPATE MUCH QUICKER THAN
STRATUS TODAY. ONE ITEM TO NOTE IS THE ECMWF...NAM12 AND WRF-NMM
DEVELOP A COUPLE SHOWERS/THUNDERSTORMS OVER EAST CENTRAL COLORADO
AND WEST CENTRAL KANSAS. INSTABILITY IS AROUND 1000-1500 J/KG OF
CAPE. HOWEVER...WITH A STRONG CAPE IN PLACE...WEAK SURFACE
CONVERGENCE AND LITTLE INDICATION OF A STRONG ENOUGH SHORTWAVE TO
OVERCOME THE CAP...DID NOT FEEL CONFIDENT ENOUGH TO MENTION A CHANCE
OF THUNDERSTORMS TOMORROW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM MDT TUE SEP 16 2014
WEDNESDAY NIGHT-THURSDAY NIGHT...UPPER RIDGE AXIS SHIFTS EAST OVER
THE AREA THURSDAY THEN SLOWLY EAST THURSDAY NIGHT. NAM MODEL HAS
BACKED OFF ON WESTWARD PUSH OF FRONTAL BOUNDARY AND POST-FRONTAL
STRATUS WEDNESDAY NIGHT...NOW LIMITING IT TO AREAS ACROSS FAR
SOUTHWEST NEBRASKA TO NORTON AND HILL CITY AREAS...SIMILAR TO THE
06Z GFS. NAM VISIBILITY FORECASTS FOR FOG IN THE STRATUS HAVE BEEN
HORRIBLE THE PAST WEEK OR SO...OVERDOING IT SIGNIFICANTLY.
HOWEVER...WITH A LIGHT EAST WIND VS SOUTHERLY THE PAST FEW POTENTIAL
EVENTS CANT RULE OUT SOME FOG SO HAVE KEPT IT GOING BUT BACKED OFF
COVERAGE JUST A BIT.
SOME ELEVATED THUNDERSTORMS POSSIBLE THROUGH MIDNIGHT WEDNESDAY
NIGHT FROM MCCOOK TO HILL CITY AND POINTS EAST WITH DECREASING
CHANCES SHORTLY AFTER AS INSTABILITY AXIS SLOWLY SHIFTS EAST.
SUNNY/MOSTLY SUNNY AND DRY THURSDAY WITH MOSTLY CLEAR CONDITIONS
THURSDAY NIGHT. A FEW CLOUDS MAY CREEP INTO THE FAR SOUTH AND
SOUTHWEST PARTS OF THE AREA HEAD OF (AS OF THIS WRITING) TROPICAL
STORM ODILE.
LOWS WEDNESDAY NIGHT IN THE MID 50S TO LOW 60S...WARMING A FEW
DEGREES FOR THURSDAY NIGHT. HIGHS THURSDAY MID 80S TO AROUND 90/LOW
90S.
FRIDAY-FRIDAY NIGHT...MOISTURE ASSOCIATED WITH (AS OF THIS WRITING)
TROPICAL STORM ODILE FORECAST TO REACH AREAS GENERALLY ALONG AND
SOUTH OF THE INTERSTATE BY 00Z SATURDAY WITH THE NAM/ECMWF FURTHEST
NORTH AND GFS QUITE A BIT TO THE SOUTH...NOT EVEN REACHING KANSAS.
FOR THIS FORECAST CYCLE HAVE TRIMMED BACK ON NORTHWARD EXTENT OF
PRECIPITATION CHANCES BY 18Z TO AREAS SOUTH OF A TRIBUNE AND LEOTI LINE.
FOR FRIDAY NIGHT GENERAL IDEA IS FOR ODILES MOISTURE TO CONTINUE
TOWARD NORTON AND HILL CITY BY 06Z BEFORE EXITING TO THE EAST AS
AN UPPER TROUGH APPROACHES FROM THE NORTHWEST.
HIGHS IN THE 80S. LOWS IN THE MID 50S TO LOW 60S...COOLEST IN FAR
EASTERN COLORADO.
SATURDAY...MID AND HIGH CLOUDS INCREASE FROM THE NORTHWEST
ASSOCIATED UPPER TROUGH PASSAGE. PLENTY OF LOW CLOUDS REMAIN ACROSS
THE SOUTHEAST HALF OF THE AREA DURING THE MORNING BEFORE DECREASING
FROM NORTHWEST TO SOUTHEAST WITH THE TROUGH. ENOUGH INSTABILITY
PRESENT TO WARRANT A SLIGHT CHANCE OF THUNDERSTORMS. DRY WEATHER
EXPECTED SATURDAY NIGHT. HIGHS IN THE MID 70S TO LOW 80S. LOWS IN
THE LOW TO MID 50S.
SUNDAY...DRY WEATHER EXPECTED. HIGHS IN THE MID TO UPPER 70S
WITH LOWS IN THE LOW TO MID 50S.
MONDAY-TUESDAY...WILL BE WATCHING MOISTURE/CLOUDINESS WORKS ITS WAY
TOWARD THE WESTERN 1/2 OF THE AREA AHEAD OF AN UPPER LOW PRESSURE
SYSTEM MAKING ITS WAY INTO THE GREAT BASIN AREA FROM THE SOUTHWEST.
MAY SEE A FEW SHOWERS/THUNDERSTORMS GENERALLY ALONG/WEST OF THE
CO/KS BORDER TUESDAY.
HIGHS BOTH DAYS IN THE 70S WITH LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1153 PM MDT TUE SEP 16 2014
VFR TO MVFR CONDITIONS FORECAST FOR THE 6Z TAFS. LATEST MODEL DATA
CONTINUING TO SUGGEST LOW VIS/CEILINGS FOR THE MORNING AT KMCK.
AM STILL HESITANT TO GO MUCH BELOW MVFR DUE TO PERSISTENT FROM
PREVIOUS DAYS...SO WILL GO TOWARD THE LOWER END OF MVFR.
CLIMATOLOGY SUGGESTS MVFR CEILINGS ARE SLIGHTLY MORE PROBABLE THAN
IFR WHICH ADDS A BIT MORE CONFIDENCE TO THE FORECAST...ALTHOUGHIFR
SLIGHTLY MORE LIKELY THAN MVFR FOR THE VIS. IN THE CLIMATOLOGY.
OTHERWISE LIGHT WINDS WILL PREVAIL THROUGH THE TAF WINDOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...RRH
LONG TERM...99
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS JACKSON KY
149 AM EDT WED SEP 17 2014
.UPDATE...
ISSUED AT 149 AM EDT WED SEP 17 2014
UPDATED TO RAMP UP THE SKY COVER HAS STRATUS IS CONTINUING TO EXPAND
THIS MORNING. ALSO...TWEAKED TEMPERATURES UP A TAD AS THE CLOUDS ARE
NOT ALLOWING TEMPERATURES TO COOL BY QUITE AS MUCH AS EARLIER
ANTICIPATED. OTHERWISE...NO OTHER CHANGES.
UPDATE ISSUED AT 1135 PM EDT TUE SEP 16 2014
ADJUSTED OVERNIGHT LOWS BASED ON CURRENT TRENDS...GENERALLY A LITTLE
COOLER IN THE NORTH. AFTERNOON POST FRONTAL CLOUDS CONTINUE TO ERODE
AS SUBSIDENCE ALOFT DRIES OUT THE ATMOSPHERE JUST ABOVE THE BOUNDARY
LAYER. CONSEQUENTLY AS SKIES CLEAR...LOWER STRATUS AND FOG HAVE BEEN
REDEVELOPING DUE TO NEAR IDEAL RADIATIVE CONDITIONS ALOFT AT THE TOP
OF THE RESIDUAL MOIST BOUNDARY/SURFACE LAYER OVER OUR FORECAST AREA.
BEEFED UP FOG IN THE GRIDS AND ZONES. ATTM NOT EXACTLY SURE HOW
WIDESPREAD FOG FORMATION WILL BE OVERNIGHT DUE TO EVENTUAL STRENGTH
OF SFC WINDS AND MIXING. AFTER DISCUSSIONS WITH NEIGHBORS...DECIDED
TO ISSUE A SPECIAL WEATHER STATEMENT TO HIGHLIGHT FOG POTENTIAL.
UPDATE ISSUED AT 858 PM EDT TUE SEP 16 2014
QUICK UPDATE TO THE ZONES TO REMOVE SPRINKLES. BROUGHT GRIDS IN LINE
WITH HOURLY OBS...TEMPS DROPPING A BIT FASTER THAN ANTICIPATED WITH
PARTIAL CLEARING. HOWEVER OVERNIGHT MINS STILL LOOK ON TRACK FOR NOW.
UPDATE ISSUED AT 713 PM EDT TUE SEP 16 2014
FORECAST IS IN GOOD SHAPE. TWEAKED GRIDS TO HOURLY OBSERVATIONS.
STILL SEEING SOME VERY LIGHT ECHOS ACROSS THE SOUTHEAST. THEREFORE
WILL HOLD OFF ON ANY UPDATE TO THE ZFP FOR A BIT LONGER BEFORE
REMOVING LIGHT SPRINKLE ACTIVITY. REGIONAL SATELLITE IS SHOWING DECENT
AMOUNT OF CLOUD EROSION AS DRY AIR FROM DEVELOPING SUBSIDENCE
INVERSION ALOFT MIXES INTO THE TOP OF THE BOUNDARY LAYER. RELATIVELY
HIGH SFC DEW POINTS REMAIN HOWEVER. CONCERN IS THAT WITH STRONG
SUBSIDENCE AND THEREFORE DRYING TAKING PLACE JUST ABOVE THE BOUNDARY
LAYER...RADIATIVE COOLING WILL BE THE CATALYST FOR LOW STRATUS AND
FOG TO REDEVELOP OVERNIGHT. WILL KEEP A CLOSE EYE ON OBSERVATIONS
THROUGH THE EVENING IN CASE A HEADLINE IS NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 350 PM EDT TUE SEP 16 2014
19Z SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXITING FAR SOUTHEAST
KENTUCKY AS A COOL AND DRY AREA OF HIGH PRESSURE PUSHES DEEPER INTO
THE OHIO VALLEY. BEHIND THIS BOUNDARY...A FEW LIGHT SHOWERS AND
PLENTY OF SPRINKLES/DRIZZLE REMAIN OVER A GOOD PORTION OF THE CWA.
ON SATELLITE...THE LOW CLOUDS ARE BREAKING UP OVER THE SOUTHERN
PORTION OF EAST KENTUCKY WHILE THEY ARE HOLDING TIGHT OVER JKL AND
POINTS NORTH. THE EXTENSIVE CLOUD COVER AND POCKETS OF LIGHT PCPN
KEPT TEMPERATURES WELL BELOW NORMAL FOR THE DAY WITH READINGS
CURRENTLY RANGING FROM A CHILLY 60 DEGREES ALONG AND NORTH OF
INTERSTATE 64 WHILE SOME 70 DEGREE READINGS HAVE SHOWN UP TO THE
SOUTH THANKS TO PARTIAL SUNSHINE. DEW POINTS VARY FROM THE MID 50S
NORTH TO THE LOWER AND MIDDLE 60S SOUTH. LIGHT NORTH WINDS ARE ADDING
TO THE CHILL THROUGH MOST OF THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH EAST KENTUCKY STILL IN
THE GRIP OF A BROAD AND UNSEASONABLY DEEP TROUGH THROUGH THE EASTERN
HALF OF THE NATION. FAIRLY FAST NORTHWEST FLOW AT THE BASE OF THIS
TROUGH WILL KEEP A SERIES OF WEAK DISTURBANCES MOVING THROUGH EAST
KENTUCKY DURING THE SHORT TERM PORTION OF THE FORECAST. THE
HEALTHIEST OF THESE ACTUALLY PASSES THROUGH DURING THE DAY WEDNESDAY
WITH A KINK IN THE FLOW LINES. GIVEN THE MODEL SIMILARITIES ALOFT
HAVE GONE WITH A GENERAL BLEND WHILE FAVORING THE HRRR AND NAM12
THROUGH THE FIRST 18 TO 24 HOURS.
SENSIBLE WEATHER WILL FEATURE THE LINGERING SHOWERS AND POCKETS OF
SPRINKLES/DRIZZLE DRYING UP BY EARLY EVENING WITH SOME CLEARING
EXPECTED FOR A TIME. HOWEVER...THIS CLEARING...WITH LITTLE IN THE
WAY OF SFC WINDS...WILL LIKELY ALLOW AREAS OF DENSE FOG AND LOW
STRATUS TO DEVELOP...RESTRICTING VISIBILITY IN MOST PLACES ACROSS
EAST KENTUCKY BY DAWN. HAVE HIT THIS HARD IN THE GRIDS AND ALSO THE
HWO. WILL LEAVE IT TO LATER SHIFTS TO MONITOR THE CLEARING...
ADVECTION...AND PRELIMINARY FOG PRODUCTION FOR A POTENTIAL ADVISORY
OR SPS. ONCE THE FOG BURNS OFF ON WEDNESDAY MORNING SOME SUNSHINE CAN
BE EXPECTED... BUT THE UPPER LEVEL ENERGY WILL LIKELY BRING IN MORE
LOW AND MID LEVEL CLOUDS. IN FACT...CANNOT COMPLETELY RULE OUT SOME
MORE SPRINKLES OR A LIGHT SHOWER AS THIS WAVE MOVES BY ALOFT
WEDNESDAY AFTERNOON. FOR NOW...THOUGH...HAVE KEPT THE POPS JUST BELOW
MENTIONING. THE WAKE OF THIS WILL SET UP ANOTHER NIGHT OF AT LEAST
PARTIAL CLEARING ALONG WITH AREAS OF FOG...LOCALLY DENSE FORMING LATE
AT NIGHT. THIS SHOULD BE THE COLDER OF THE NIGHTS WITH SOME UPPER 40S
POSSIBLE IN THE VALLEYS THROUGH THE NORTHERN HALF OF THE AREA...AND
ELSEWHERE IF THE CLEARING AND FOG ALLOW IT.
AGAIN USED THE CONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE FIRST 24 HOURS BEFORE LOADING THE SUPER BLEND THEREAFTER.
DID NUDGE THE LOWS TONIGHT AND ESPECIALLY WEDNESDAY NIGHT FOR RIDGE
AND VALLEY DIFFERENCES. AS FOR POPS...ENDED UP HIGHER THAN MOS IN THE
NEAR TERM AND ALSO FOR LATER WEDNESDAY...OTHERWISE KEPT THE POPS LOW
SIMILAR TO THE GUIDANCE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 PM EDT TUE SEP 16 2014
THURSDAY MORNING STARTS THE EXTENDED PERIOD WITH AN AMPLIFIED UPPER
LEVEL PATTERN. STRONG TROUGHING WILL EXIST ACROSS MUCH OF THE
EASTERN THIRD OF THE CONUS...WHILE HIGH PRESSURE RIDGING REMAINS
PARKED ACROSS THE SOUTHWESTERN STATES. THIS PATTERN WILL REMAIN IN
PLACE THROUGH FRIDAY...BEFORE IT STARTS TO BREAK DOWN AND HEIGHTS
BEGIN TO BUILD ACROSS EASTERN KY INTO THE DAY SATURDAY. N/NW WINDS
WILL USHER IN COLD WINDS DURING THE DAY THURSDAY...WITH HIGHS ONLY
REACHING THE LOW TO MID 70S. THIS WILL NOT
CONTINUE...HOWEVER...AS A SHORTWAVE MOVES TOWARDS THE REGION DURING
THE DAY FRIDAY. AT THE SURFACE...A POTENT COLD FRONT WILL BE MAKING
ITS WAY FROM THE NORTHERN PLAINS TOWARDS KY...WITH SRLY WINDS
PULLING UP WARM AIR OUT AHEAD OF THE FRONT. THIS WILL RESULT IN
INCREASING TEMPERATURES FRIDAY...REACHING MORE SEASONABLE UPPER 70S
AND LOW 80S FOR BOTH FRIDAY AND SATURDAY.
THE FRONT WILL LOSE STRENGTH AS IT MOVES TOWARDS THE EASTERN KY
REGION AS UPPER LEVEL HEIGHTS CONTINUE TO BUILD INTO THE WEEKEND. BY
THE TIME THE SYSTEM REACHES EASTERN KY...THERE WILL BE VERY LITTLE
INSTABILITY LEFT...AS WELL AS VERY LITTLE CONCERN FOR PWAT VALUES.
MODELS ARE STILL SLIGHTLY DIFFERENT ON THE EXACT TIMING AND EXTENT
OF THE PRECIPITATION...SO WILL CONTINUE TO STICK CLOSE TO A MODEL
BLEND. AS SUCH...EXPECT THE PRECIP TO MOVE AHEAD OF THE FRONT AND
INTO EASTERN KY BETWEEN 12 AND 18Z SUNDAY...AND CONTINUE INTO EARLY
AFTERNOON MONDAY. DESPITE LACK OF INSTABILITY...NEIGHBORING OFFICES
CONTINUE TO FAVOR THE FACT THAT THE FRONTAL BOUNDARY LIFT ALONE MAY
BE ENOUGH TO INITIATE SOME THUNDER. AS SUCH...KEPT IN ONLY SLIGHT
MENTION OF THUNDER AS THE LINE MAKES IT THROUGH KY SUNDAY INTO
MONDAY...WITH THE EXCEPTION OF SUNDAY AFTERNOON...WHERE IT SEEMS THE
INCOMING FRONT WILL BRING A BRIEF PERIOD OF HEIGHTENED INSTABILITY
WITH AFTERNOON HEATING...AND THEREFORE CHANCES WERE INCLUDED.
TEMPS WILL COOL SUBSTANTIALLY BEHIND THE FRONTAL PASSAGE BY DURING
THE DAY MONDAY. UPPER LEVEL RIDGING WILL SLOWLY MOVE IN OVERHEAD
INTO THE DAY TUESDAY...WHILE AT THE SURFACE BROAD HIGH PRESSURE
TAKES CONTROL. SURFACE WINDS WILL BECOME MORE NORTHERLY...AS STRONG
W/NW WINDS ALOFT. THIS WILL RESULT IN THE RETURN OF ANOTHER
UNSEASONABLY COOL AIR MASS AND HIGH TEMPERATURES ONLY TOPPING OUT IN
THE LOW TO MID 70S. TEMPS WILL CONTINUE TO DETERIORATE BY THE DAY
TUESDAY...WITH HIGHS IN THE UPPER 60S TO AROUND 70S EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 149 AM EDT WED SEP 17 2014
STRATUS CONTINUES TO DEVELOP AND SLOWLY BUILD DOWN. THIS WILL
CONTINUE THROUGH DAYBREAK...WITH THE RIDGE TOPS REALLY GETTING SOCKED
IN OVER THE NEXT FEW HOURS. FOG MAY BE MORE SPORADIC IN THE VALLEYS
AND NOT QUITE AS DENSE. HOWEVER...GIVEN MANY OF THE RIDGETOP
AIRPORTS...THIS WILL BRING MANY SPOTS BELOW AIRPORT MINIMUMS LATE
TONIGHT. FOG/STRATUS WILL BEGIN TO LIFT/BURN OFF AFTER SUNRISE...BUT
MAY TAKE A GOOD 2 TO 3 HOURS BEFORE THIS PROCESS IS COMPLETE. WE
SHOULD SEE A RETURN TO VFR CONDITIONS FOR ALL AREAS BY LATE MORNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
229 PM EDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT WED SEP 17 2014
LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A SHORTWAVE MOVING
INTO WRN ONTARIO WITH ITS ASSOC UPPER JET MAX PASSING ACROSS THE TIP
OF JAMES BAY. 850 MB FGEN ALONG THE SYSTEMS COLD FRONT IS SUPPORTING
BAND OF SHRA FROM JUST NORTH OF MN BDR EXTENDING ACROSS NCNTRL AND
ERN LAKE SUPERIOR AS NOTED ON CANADIAN RADAR MOSIAC. SOME OF THESE
SHRA HAVE BRUSHED THE KEWEENAW PENINSULA EARLY THIS MORNING AND LOW
CLOUDS HAVE REACHED INTO KCMX AS WELL. OTHERWISE THE REST OF THE CWA
HAS STAYED DRY THUS FAR.
TODAY...AS THE ONTARIO SHORTWAVE DIVES ACROSS THE NRN TIP OF LAKE
SUPERIOR LATER THIS MORNING IT WILL HELP DRIVE THE COLD FRONT ACROSS
UPPER MI LATE THIS MORNING INTO THE AFTERNOON HRS. MODELS SHOW
SUPPORTING 850 MB FGEN FORCING FOR SHRA ACTIVITY GENERALLY WEAKENING
AND MOVING EAST BY LATE MORNING WITH DEPARTING SHORTWAVE AND ASSOC
UPPER JET MAX AS COLD FRONT SLOWLY BEGINS TO SHIFT SOUTH ACROSS THE
AREA. SINCE THE MODELS INDICATE THE BEST FGEN FORCING GENERALLY
STAYING OUT OVER LAKE SUPERIOR OR NORTH OF THE LAKE THROUGH LATE
MORNING HAVE KEPT HIGHER CHC/LIKELY POPS WELL NORTH OVER LAKE
SUPERIOR THIS MORNING WITH ONLY SLIGHT CHC TO LOW CHC POPS BRUSHING
THE KEWEENAW PENINSULA AND THE FAR NE CWA. THE REST OF THE CWA SHOULD
STAY GENERALLY DRY TODAY AS FGEN WILL BE WEAKENING QUICKLY ALONG THE
FRONT AS IT BEGINS TO MOVE SOUTH ACROSS UPPER MI THIS AFTERNOON.
SINCE COLD FRONTAL PASSAGE WILL BE LATER IN THE DAY FOR ALL BUT THE
NW QUARTER OF THE CWA...EXPECT TEMPS TO WARM UP INTO THE 60S OVER
SCNTRL AND ERN PORTIONS OF THE CWA WITH THE COOLEST TEMPS (AROUND
50F) ACROSS THE KEWEENAW PENINSULA. TEMPS ACROSS THE N WILL LIKELY
FALL INTO THE 40S IN THE AFTN UNDER A BRISK DEVELOPING NRLY WIND AND
STRATUS DECK FOLLOWING FROPA.
TONIGHT...CANADIAN HIGH PRESSURE BUILDING ACROSS THE AREA AND
BECOMING CENTERED NE OF LAKE SUPERIOR WILL BRING CLEARING SKIES AND
LIGHT EASTERLY WINDS. PWATS LESS THAN 30 PCT OF NORMAL OR LESS THAN
.25 INCH WILL ALLOW FOR IDEAL RADIATIONAL COOLING CONDITIONS. EXPECT
FREEZING TO BLO FREEZING TEMPS ACROSS MUCH OF THE INTERIOR OF THE
UPPER MI. HAVE POSTED FREEZE WARNINGS FOR THE INTERIOR WRN COUNTIES
AND HAVE FROST ADVISORIES OUT FOR THE REST OF THE CWA WITH THE
EXCEPTION OF KEWEENAW COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM EDT WED SEP 17 2014
NOT MUCH CHANGE IN THINKING FROM PREVIOUS SHIFT. THU WILL START WITH
LINGERING COLD AND FROST FROM WED NIGHT AS A 1025MB SFC HIGH WILL BE
CENTERED JUST NE OF THE CWA AT 12Z THU. THE HIGH WILL MOVE TO NEW
ENGLAND...WHILE STRENGTHENING TO 1030MB...BY 12Z FRI WHILE A SFC
TROUGH MOVES TO THE DAKOTAS. RETURN FLOW/WAA WILL JUST BE STARTING
LATE THU...SO DRY AIR LINGERING OVER THE REGION WILL MAKE FOR MOSTLY
SUNNY SKIES ON THU. TEMPS ON THU WILL TOP OUT IN THE MID TO UPPER
50S.
MOISTURE BEGINS TO INCREASE THU NIGHT AS THE RETURN FLOW
INCREASES...BUT MOST PRECIP LOOKS TO HOLD OFF UNTIL FRI WHEN AMPLE
MOISTURE WILL BE ESTABLISHED...A SERIES OF SHORTWAVE TROUGHS BEGINS
A TREK ACROSS THE AREA...AND THE PRESSURE GRADIENT/RETURN FLOW
INCREASES. MODELS ARE IN GOOD AGREEMENT ON THE START TIME OF PRECIP
FRI IN THE WAA REGIME...BUT HOW THINGS SHAPE UP ON FRIDAY AND
ESPECIALLY THE END TIME OF PRECIP ON SAT NIGHT OR SUN IS MORE
UNCERTAIN. EVEN THOUGH MODELS AGREE THAT THE STRONGEST SHORTWAVE
WILL ENTER THE REGION LATE SAT INTO SAT NIGHT...MODELS DISAGREE WITH
EACH OTHER AND FROM RUN TO RUN DUE TO THE COMPLEX NATURE OF PHASING
THE THREE WAVES OVER THE AREA. WILL LIKELY NOT HAVE GREATER
CERTAINTY ON END TIME OF PRECIP UNTIL CLOSER TO THE WEEKEND. HAVE
THE GREATEST POPS FROM LATE FRI THROUGH SAT. CONTINUED TO HAVE
CHANCES FOR THUNDERSTORMS LATE FRI INTO SAT NIGHT WHEN SOME ELEVATED
INSTABILITY IS EXPECTED...NO SEVERE WEATHER IS EXPECTED THOUGH.
850MB TEMPS WILL TOP OUT AROUND 15C FRI NIGHT INTO SAT...RESULTING
IN HIGH TEMPS IN THE MID 60S TO LOW 70S /WHICH IS AROUND AVERAGE/.
THE AIRMASS WILL BE COLDER SUN THROUGH TUE UNDER STRONGER NW FLOW
ALONG AND INCOMING SFC HIGH PRESSURE...RESULTING IN COOLER AND DRIER
CONDITIONS MON AND TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 227 PM EDT WED SEP 17 2014
LIGHT SHOWERS ASSOCIATED WITH THE EXITING FRONTAL BOUNDARY SINKING
ACROSS CENTRAL UPPER MI WILL CONTINUE ACROSS THE AREA WILL CONTINUE
ACROSS WI AND N LOWER MI THIS AFTERNOON. THE INCREASE IN MOISTURE
AND FAVORABLE UPSLOPE CONDITIONS HAS RESULTED IN BR OVER THE HIGHER
TERRAIN OF CENTRAL UPPER MI...AND LIFR CEILINGS AT IWD AND SAW.
CURRENT LIFR CEILINGS AT CMX AND SAW WILL SLOWLY IMPROVE THROUGH THE
LATE AFTERNOON HOURS. CURRENT TRACKING OF THE BACK SIDE OF THE
CLOUDS ACROSS CENTRAL LAKE SUPERIOR BRINGS VFR CEILINGS BACK BY
AROUND 21Z AT CMX...AND BY 23Z AT SAW AND IWD. WINDS WILL SLOWLY
TURN MORE NE TO E OVERNIGHT...AS DRIER AIR FILTER IN. EXPECT WINDS
TO REMAIN BELOW 10KTS WITH VFR CEILINGS TONIGHT THROUGH
THURSDAY...UNDER VFR CEILINGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT WED SEP 17 2014
EXPECT WINDS GENERALLY 10-20KT AS THE FRONT STALLS OVER THE LAKE
EARLY THIS MORNING. FRONT WILL GET A PUSH S LATE THIS MORNING INTO
THE AFTERNOON WITH NE WINDS BEHIND THE FRONT INCREASING TO 15-25KT FOR
AT LEAST A TIME. OVER FAR WRN LAKE SUPERIOR...COASTAL
CONVERGENCE/FUNNELING MAY RESULT IN WINDS BRIEFLY AS HIGH AS 30KT.
WINDS WILL THEN DIMINISH TO UNDER 20KT TONIGHT/THU AS HIGH PRES
SETTLES OVER NRN ONTARIO IN THE VCNTY OF LAKE SUPERIOR. AS THE HIGH
THEN SHIFTS TOWARD NEW ENGLAND AND A LOW PRES TROF APPROACHES FROM
THE W...S WINDS WILL INCREASE THU NIGHT/FRI. WITH S WINDS A MORE
FAVORABLE DIRECTION FOR STRONGER WINDS OVER ERN LAKE SUPERIOR THAN
OVER THE W...WINDS SHOULD REACH 20-30KT OVER THE ERN LAKE ON FRI.
ALTHOUGH WINDS WILL DIMINISH ON SAT AS THE TROF ARRIVES OVER THE
UPPER LAKES...W TO NW WINDS WILL AGAIN INCREASE TO AS HIGH AS
20-30KT BEHIND THE TROF SAT NIGHT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ003-005>007-012>014-085.
FREEZE WARNING FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...KF
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM EDT WED SEP 17 2014
LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A SHORTWAVE MOVING
INTO WRN ONTARIO WITH ITS ASSOC UPPER JET MAX PASSING ACROSS THE TIP
OF JAMES BAY. 850 MB FGEN ALONG THE SYSTEMS COLD FRONT IS SUPPORTING
BAND OF SHRA FROM JUST NORTH OF MN BDR EXTENDING ACROSS NCNTRL AND
ERN LAKE SUPERIOR AS NOTED ON CANADIAN RADAR MOSIAC. SOME OF THESE
SHRA HAVE BRUSHED THE KEWEENAW PENINSULA EARLY THIS MORNING AND LOW
CLOUDS HAVE REACHED INTO KCMX AS WELL. OTHERWISE THE REST OF THE CWA
HAS STAYED DRY THUS FAR.
TODAY...AS THE ONTARIO SHORTWAVE DIVES ACROSS THE NRN TIP OF LAKE
SUPERIOR LATER THIS MORNING IT WILL HELP DRIVE THE COLD FRONT ACROSS
UPPER MI LATE THIS MORNING INTO THE AFTERNOON HRS. MODELS SHOW
SUPPORTING 850 MB FGEN FORCING FOR SHRA ACTIVITY GENERALLY WEAKENING
AND MOVING EAST BY LATE MORNING WITH DEPARTING SHORTWAVE AND ASSOC
UPPER JET MAX AS COLD FRONT SLOWLY BEGINS TO SHIFT SOUTH ACROSS THE
AREA. SINCE THE MODELS INDICATE THE BEST FGEN FORCING GENERALLY
STAYING OUT OVER LAKE SUPERIOR OR NORTH OF THE LAKE THROUGH LATE
MORNING HAVE KEPT HIGHER CHC/LIKELY POPS WELL NORTH OVER LAKE
SUPERIOR THIS MORNING WITH ONLY SLIGHT CHC TO LOW CHC POPS BRUSHING
THE KEWEENAW PENINSULA AND THE FAR NE CWA. THE REST OF THE CWA SHOULD
STAY GENERALLY DRY TODAY AS FGEN WILL BE WEAKENING QUICKLY ALONG THE
FRONT AS IT BEGINS TO MOVE SOUTH ACROSS UPPER MI THIS AFTERNOON.
SINCE COLD FRONTAL PASSAGE WILL BE LATER IN THE DAY FOR ALL BUT THE
NW QUARTER OF THE CWA...EXPECT TEMPS TO WARM UP INTO THE 60S OVER
SCNTRL AND ERN PORTIONS OF THE CWA WITH THE COOLEST TEMPS (AROUND
50F) ACROSS THE KEWEENAW PENINSULA. TEMPS ACROSS THE N WILL LIKELY
FALL INTO THE 40S IN THE AFTN UNDER A BRISK DEVELOPING NRLY WIND AND
STRATUS DECK FOLLOWING FROPA.
TONIGHT...CANADIAN HIGH PRESSURE BUILDING ACROSS THE AREA AND
BECOMING CENTERED NE OF LAKE SUPERIOR WILL BRING CLEARING SKIES AND
LIGHT EASTERLY WINDS. PWATS LESS THAN 30 PCT OF NORMAL OR LESS THAN
.25 INCH WILL ALLOW FOR IDEAL RADIATIONAL COOLING CONDITIONS. EXPECT
FREEZING TO BLO FREEZING TEMPS ACROSS MUCH OF THE INTERIOR OF THE
UPPER MI. HAVE POSTED FREEZE WARNINGS FOR THE INTERIOR WRN COUNTIES
AND HAVE FROST ADVISORIES OUT FOR THE REST OF THE CWA WITH THE
EXCEPTION OF KEWEENAW COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM EDT WED SEP 17 2014
NOT MUCH CHANGE IN THINKING FROM PREVIOUS SHIFT. THU WILL START WITH
LINGERING COLD AND FROST FROM WED NIGHT AS A 1025MB SFC HIGH WILL BE
CENTERED JUST NE OF THE CWA AT 12Z THU. THE HIGH WILL MOVE TO NEW
ENGLAND...WHILE STRENGTHENING TO 1030MB...BY 12Z FRI WHILE A SFC
TROUGH MOVES TO THE DAKOTAS. RETURN FLOW/WAA WILL JUST BE STARTING
LATE THU...SO DRY AIR LINGERING OVER THE REGION WILL MAKE FOR MOSTLY
SUNNY SKIES ON THU. TEMPS ON THU WILL TOP OUT IN THE MID TO UPPER
50S.
MOISTURE BEGINS TO INCREASE THU NIGHT AS THE RETURN FLOW
INCREASES...BUT MOST PRECIP LOOKS TO HOLD OFF UNTIL FRI WHEN AMPLE
MOISTURE WILL BE ESTABLISHED...A SERIES OF SHORTWAVE TROUGHS BEGINS
A TREK ACROSS THE AREA...AND THE PRESSURE GRADIENT/RETURN FLOW
INCREASES. MODELS ARE IN GOOD AGREEMENT ON THE START TIME OF PRECIP
FRI IN THE WAA REGIME...BUT HOW THINGS SHAPE UP ON FRIDAY AND
ESPECIALLY THE END TIME OF PRECIP ON SAT NIGHT OR SUN IS MORE
UNCERTAIN. EVEN THOUGH MODELS AGREE THAT THE STRONGEST SHORTWAVE
WILL ENTER THE REGION LATE SAT INTO SAT NIGHT...MODELS DISAGREE WITH
EACH OTHER AND FROM RUN TO RUN DUE TO THE COMPLEX NATURE OF PHASING
THE THREE WAVES OVER THE AREA. WILL LIKELY NOT HAVE GREATER
CERTAINTY ON END TIME OF PRECIP UNTIL CLOSER TO THE WEEKEND. HAVE
THE GREATEST POPS FROM LATE FRI THROUGH SAT. CONTINUED TO HAVE
CHANCES FOR THUNDERSTORMS LATE FRI INTO SAT NIGHT WHEN SOME ELEVATED
INSTABILITY IS EXPECTED...NO SEVERE WEATHER IS EXPECTED THOUGH.
850MB TEMPS WILL TOP OUT AROUND 15C FRI NIGHT INTO SAT...RESULTING
IN HIGH TEMPS IN THE MID 60S TO LOW 70S /WHICH IS AROUND AVERAGE/.
THE AIRMASS WILL BE COLDER SUN THROUGH TUE UNDER STRONGER NW FLOW
ALONG AND INCOMING SFC HIGH PRESSURE...RESULTING IN COOLER AND DRIER
CONDITIONS MON AND TUE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 721 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW TONIGHT AS LOW LEVELS
REMAIN DRY. COLD FRONT CURRENTLY OVER ONTARIO WILL DROP S INTO
PORTIONS OF NRN UPPER MI TONIGHT BEFORE STALLING AS SUBTLE SFC LOW
PRES DEVELOPS AND TRACKS ESE ALONG FRONT TOWARD THE UPPER GREAT
LAKES. IT IS EXPECTED THAT LOW CLOUDS AND BAND OF RAIN THAT WILL
DEVELOP N OF FRONT WILL PASS JUST N OF KCMX LATE TONIGHT. AS THE
VERY WEAK SFC LOW PASSES WED MORNING...COLD FRONT WILL PUSH
S...BRINGING LOW MVFR CIGS TO ALL TERMINALS. IFR NOT OUT OF THE
QUESTION AT KCMX AND ESPECIALLY KSAW WHICH WILL SEE A MORE DIRECT
UPSLOPE WIND AFTER FROPA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 456 AM EDT WED SEP 17 2014
EXPECT WINDS GENERALLY 10-20KT AS THE FRONT STALLS OVER THE LAKE
EARLY THIS MORNING. FRONT WILL GET A PUSH S LATE THIS MORNING INTO
THE AFTERNOON WITH NE WINDS BEHIND THE FRONT INCREASING TO 15-25KT FOR
AT LEAST A TIME. OVER FAR WRN LAKE SUPERIOR...COASTAL
CONVERGENCE/FUNNELING MAY RESULT IN WINDS BRIEFLY AS HIGH AS 30KT.
WINDS WILL THEN DIMINISH TO UNDER 20KT TONIGHT/THU AS HIGH PRES
SETTLES OVER NRN ONTARIO IN THE VCNTY OF LAKE SUPERIOR. AS THE HIGH
THEN SHIFTS TOWARD NEW ENGLAND AND A LOW PRES TROF APPROACHES FROM
THE W...S WINDS WILL INCREASE THU NIGHT/FRI. WITH S WINDS A MORE
FAVORABLE DIRECTION FOR STRONGER WINDS OVER ERN LAKE SUPERIOR THAN
OVER THE W...WINDS SHOULD REACH 20-30KT OVER THE ERN LAKE ON FRI.
ALTHOUGH WINDS WILL DIMINISH ON SAT AS THE TROF ARRIVES OVER THE
UPPER LAKES...W TO NW WINDS WILL AGAIN INCREASE TO AS HIGH AS
20-30KT BEHIND THE TROF SAT NIGHT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ003-005>007-012>014-085.
FREEZE WARNING FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
304 AM EDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 409 PM EDT TUE SEP 16 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A RIDGE OVER WRN NAMERICA
AND A TROF OVER ERN NAMERICA. IN THE TROF...ONE SHORTWAVE IS MOVING
E OF JAMES BAY WITH SECOND JUST UPSTREAM IN FAR NRN ONTARIO. NW FLOW
ACROSS CNTRL CANADA IS SENDING THE NEXT SHORTWAVE SE INTO NRN
SASKATCHEWAN/NRN MANITOBA. AT THE SFC...COLD FRONT ASSOCIATED WITH
THE FIRST SHORTWAVE EXTENDS FROM SRN JAMES BAY TO JUST N OF LAKE
SUPERIOR TO FAR SRN MANITOBA. REGIONAL RADAR DISPLAY HAS SHOWN -SHRA
IN THE VCNTY OF THE COLD FRONT WITH PCPN AS FAR S AS NRN LAKE
SUPERIOR. PCPN HAS BEEN WEAKENING/DISSIPATING OVER THE LAST FEW HRS.
OVER UPPER MI...MOSTLY SUNNY SKIES HAVE ALLOWED TEMPS TO RISE TO 60
TO 70 THIS AFTN.
WHILE COLD FRONT TO THE N WILL CONTINUE TO DRIFT S AND THEN STALL
TONIGHT...IT WILL BE THE THIRD IN THE AFORMENTIONED TRIO OF
SHORTWAVES THAT WILL HELP PROPEL IT S THRU THE AREA ON WED. IN
RESPONSE TO THAT THIRD SHORTWAVE AND UNDER THE RIGHT ENTRANCE OF
UPPER JET OVER NRN ONTARIO/QUEBEC...A SUBTLE SFC WAVE IS ALSO
EXPECTED TO DEVELOP ALONG THE COLD FRONT AND TRACK ACROSS SOUTHERN
LAKE SUPERIOR OR UPPER MI VERY LATE TONIGHT THRU WED MORNING. A NICE
CORRESPONDING RIBBON OF LOW-LEVEL FRONTOGENESIS ALSO DEVELOPS.
SO...MODELS LOOK ON TRACK IN GENERATING A BAND OF -SHRA N OF COLD
FRONT AND PATH OF WEAK SFC WAVE TONIGHT/WED. UTILIZED A CONSENSUS OF
MODEL GUIDANCE IN PARTICULAR HIGHER RES MODELS TO CONSTRUCT PCPN
FCST FOR TONIGHT/WED IN ORDER TO MINIMIZE SLIGHT DIFFERENCES NOTED
IN COLD FRONT WHICH AFFECTS PCPN PLACEMENT. BASED ON LOCATION OF THE
STREAK OF FRONTOGENESIS...EXPECT MOST OF THE -SHRA TO PASS JUST N
AND E OF UPPER MI VERY LATE TONIGHT AND WED MORNING. SO...CHC POPS
WERE PAINTED ACROSS THE KEWEENAW AND ERN FCST AREA. OTHERWISE...
NOTHING MORE THAN SCHC POPS WERE USED.
TEMPS WED ARE TRICKY AS THERE WILL BE AN OPPORTUNITY FOR SOME
WARMING BEFORE FROPA. ACROSS THE N...FRONT SHOULD PASS EARLY ENOUGH
TO LIMIT MUCH WARMING. HIGHS OVER THE N SHOULD RANGE FROM THE UPPER
40S ACROSS THE TIP OF THE KEWEENAW TO MID 50S ELSEWHERE. AFTER
FROPA...TEMPS ACROSS THE N WILL LIKELY FALL INTO THE 40S IN THE
AFTN UNDER A BRISK NRLY WIND AND STRATUS DECK FOLLOWING FROPA.
ACROSS THE S...NUDGED HIGH TEMPS UP...TO AS HIGH AS THE UPPER 60S
FAR SCNTRL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 AM EDT WED SEP 17 2014
NOT MUCH CHANGE IN THINKING FROM PREVIOUS SHIFT. THU WILL START WITH
LINGERING COLD AND FROST FROM WED NIGHT AS A 1025MB SFC HIGH WILL BE
CENTERED JUST NE OF THE CWA AT 12Z THU. THE HIGH WILL MOVE TO NEW
ENGLAND...WHILE STRENGTHENING TO 1030MB...BY 12Z FRI WHILE A SFC
TROUGH MOVES TO THE DAKOTAS. RETURN FLOW/WAA WILL JUST BE STARTING
LATE THU...SO DRY AIR LINGERING OVER THE REGION WILL MAKE FOR MOSTLY
SUNNY SKIES ON THU. TEMPS ON THU WILL TOP OUT IN THE MID TO UPPER
50S.
MOISTURE BEGINS TO INCREASE THU NIGHT AS THE RETURN FLOW
INCREASES...BUT MOST PRECIP LOOKS TO HOLD OFF UNTIL FRI WHEN AMPLE
MOISTURE WILL BE ESTABLISHED...A SERIES OF SHORTWAVE TROUGHS BEGINS
A TREK ACROSS THE AREA...AND THE PRESSURE GRADIENT/RETURN FLOW
INCREASES. MODELS ARE IN GOOD AGREEMENT ON THE START TIME OF PRECIP
FRI IN THE WAA REGIME...BUT HOW THINGS SHAPE UP ON FRIDAY AND
ESPECIALLY THE END TIME OF PRECIP ON SAT NIGHT OR SUN IS MORE
UNCERTAIN. EVEN THOUGH MODELS AGREE THAT THE STRONGEST SHORTWAVE
WILL ENTER THE REGION LATE SAT INTO SAT NIGHT...MODELS DISAGREE WITH
EACH OTHER AND FROM RUN TO RUN DUE TO THE COMPLEX NATURE OF PHASING
THE THREE WAVES OVER THE AREA. WILL LIKELY NOT HAVE GREATER
CERTAINTY ON END TIME OF PRECIP UNTIL CLOSER TO THE WEEKEND. HAVE
THE GREATEST POPS FROM LATE FRI THROUGH SAT. CONTINUED TO HAVE
CHANCES FOR THUNDERSTORMS LATE FRI INTO SAT NIGHT WHEN SOME ELEVATED
INSTABILITY IS EXPECTED...NO SEVERE WEATHER IS EXPECTED THOUGH.
850MB TEMPS WILL TOP OUT AROUND 15C FRI NIGHT INTO SAT...RESULTING
IN HIGH TEMPS IN THE MID 60S TO LOW 70S /WHICH IS AROUND AVERAGE/.
THE AIRMASS WILL BE COLDER SUN THROUGH TUE UNDER STRONGER NW FLOW
ALONG AND INCOMING SFC HIGH PRESSURE...RESULTING IN COOLER AND DRIER
CONDITIONS MON AND TUE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 721 PM EDT TUE SEP 16 2014
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW TONIGHT AS LOW LEVELS
REMAIN DRY. COLD FRONT CURRENTLY OVER ONTARIO WILL DROP S INTO
PORTIONS OF NRN UPPER MI TONIGHT BEFORE STALLING AS SUBTLE SFC LOW
PRES DEVELOPS AND TRACKS ESE ALONG FRONT TOWARD THE UPPER GREAT
LAKES. IT IS EXPECTED THAT LOW CLOUDS AND BAND OF RAIN THAT WILL
DEVELOP N OF FRONT WILL PASS JUST N OF KCMX LATE TONIGHT. AS THE
VERY WEAK SFC LOW PASSES WED MORNING...COLD FRONT WILL PUSH
S...BRINGING LOW MVFR CIGS TO ALL TERMINALS. IFR NOT OUT OF THE
QUESTION AT KCMX AND ESPECIALLY KSAW WHICH WILL SEE A MORE DIRECT
UPSLOPE WIND AFTER FROPA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT TUE SEP 16 2014
AHEAD OF AN APPROACHING COLD FRONT FROM THE N...SW WINDS AS HIGH AS
15-25KT THIS EVENING WILL FALL BACK TO GENERALLY 10-20KT TONIGHT AS
THE FRONT STALLS OVER THE AREA. FRONT WILL GET A PUSH S ON WED...AND
NE WINDS BEHIND THE FRONT WILL INCREASE TO 15-25KT FOR AT LEAST A
TIME. OVER FAR WRN LAKE SUPERIOR...COASTAL CONVERGENCE/FUNNELING
WILL PROBABLY RESULT IN WINDS AS HIGH AS 30KT LOCALLY. WINDS WILL
THEN DIMINISH TO UNDER 20KT WED NIGHT/THU AS HIGH PRES SETTLES OVER
NRN ONTARIO IN THE VCNTY OF LAKE SUPERIOR. AS THE HIGH THEN SHIFTS
TOWARD NEW ENGLAND AND A LOW PRES TROF APPROACHES FROM THE W...S
WINDS WILL INCREASE THU NIGHT/FRI. WITH S WINDS A MORE FAVORABLE
DIRECTION FOR STRONGER WINDS OVER ERN LAKE SUPERIOR THAN OVER THE
W...WINDS SHOULD REACH 20-30KT OVER THE ERN LAKE ON FRI. ALTHOUGH
WINDS WILL DIMINISH ON SAT AS THE TROF ARRIVES OVER THE UPPER
LAKES...W TO NW WINDS WILL AGAIN INCREASE TO AS HIGH AS 20-30KT
BEHIND THE TROF SAT NIGHT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ003-005>007-012>014-085.
FREEZE WARNING FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO 10 AM
EDT /9 AM CDT/ THURSDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
135 AM CDT Wed Sep 17 2014
.UPDATE:
Issued at 129 AM CDT Wed Sep 17 2014
Based on latest vsby trends of surface obs as well as HRRR and
lamp guidance will be going out with a dense fog advisory for our
eastern counties shortly...until 10am. It`s possible we may need
to expand a bit west and north in a few hours, and will at least
mention patchy fog as far west as eastern MO. However, upstream
clouds heading our direction should limit threat of widespread
dense fog, especially west of the Mississippi River.
Truett
&&
.SHORT TERM: (Through Tonight)
Issued at 230 PM CDT Tue Sep 16 2014
A weak s/w will approach the CWA late tonight bringing a chance
for storms to wrn and srn portions of the CWA late tonight.
Otherwise, expect clouds to continue to break up during the
afternoon and into the evening. Clouds are expected to build into
the region from the W tonight ahead of the s/w. Have trended twd
a compromise of guidance for wrn portions of the CWA and twd the
cooler guidance for ern portions. Latest guidance suggests FG will
develop late tonight impacting srn and ern portions of the CWA
where radiational cooling will be greatest.
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 309 PM CDT Tue Sep 16 2014
(Wednesday through Friday)
Main concern continues to be rain chances tomorrow into tomorrow
night over mainly central and southeast Missouri. GFS/NAM/ECMWF are
still in relatively good agreement in dropping a weak shortwave
trough across Missouri during the day tomorrow. Each of these
models shows some weak low level moisture lingering across central
and southeast Missouri into Wednesday night, so will continue a
chance of showers and thunderstorms in this area. This scenario is
depicted pretty well at least through 00Z by the reflectivity on the
NSSL WRF. Thereafter will maintain a dry forecast Thursday and
Friday as a surface ridge moves across the area at the same time a
upper ridge builds in from the west.
Went on the cooler side of guidance for highs the next couple of
days given the easterly surface flow and it matches up better with
mixing down the 900mb temperatures. Likewise followed the cooler
NAM MOS for lows.
(Saturday through next Tuesday)
While there is still some disagreement between the GFS/ECMWF
regarding the speed and depth of a trough that will pass through the
area this weekend, it still appears that the attendant cold front
will move through on Saturday night and early Sunday. Will keep
chances of showers and thunderstorms going Saturday into Sunday.
Will keep Monday and Tuesday dry at this point as we will be on the
back side of the the upper trough, though the latest runs of the GFS
is showing a secondary through dropping down in the northwesterly
flow on Tuesday. This is a new trend that the ECMWF is not
showing. Still expect at or just above normal temperatures ahead of
the front on Saturday before they drop back below normal for early
next week given expected 850mb temperatures in the 6-9C
range.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1104 PM CDT Tue Sep 16 2014
Northwest flow aloft will keep the mid Fall like conditions in
place. Upper air wave will move through overnight to reinforce the
northwest flow. Models trying to generate precitation at the nose
of a low level (5000 ft) jet of 30 knots over the MO/KS border. So
far no sign of anything develping. COU looks to be the only
location with a shot at rain, but will keep them dry for now. Band
of 4k to 5k clouds rapidly advancing SE. That may put a stop to
any MVFR ceilings. Lower clouds over southern MO are slowly
expanding a bit to the north. Some fog at SUS and CPS will will
bring temporary MVFR conditions until the clouds arrive. Wednesday
looks to be VFR.
Specifics for KSTL: 4k to 5k deck should arrive from 08 to 09z.
Will go with that and hold off on any MVFR ceilings. Lower clouds
over south central MO may work their way north and the MAV
guiidance brings them in for a short time. Not that confident they
will arrive, so will leave out for now.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...DENSE FOG ADVISORY until 10 AM CDT this morning FOR Bond IL-
Clinton IL-Fayette IL-Marion IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1116 PM CDT Tue Sep 16 2014
.UPDATE:
Issued at 845 PM CDT Tue Sep 16 2014
Going forecast looks on track this evening. Sky is clear/mostly
clear across the area with just a bit of cloud cover hanging in
across our SE MO counties. Short range guidance continues to show
an increasing amount of low level moisture convergence over
eastern Kansas/western Missouri this evening with convection
breaking out between 06Z-08Z. Models are pretty consistent in
keeping all but perhaps a few showers out of our area through 12Z
with the lion`s share of the precip back over southwest Missouri.
Should see scattered showers and thunderstorms spread into parts
of central and eastern Missouri later Wednesday morning. RAP and
HRRR seem to want to bring some showers into northeast Missouri by
15Z as well...and I may tweak the PoPs up before sending out the
midnight update if the new 00Z NAM and GFS agree.
Carney
&&
.SHORT TERM: (Through Tonight)
Issued at 230 PM CDT Tue Sep 16 2014
A weak s/w will approach the CWA late tonight bringing a chance
for storms to wrn and srn portions of the CWA late tonight.
Otherwise, expect clouds to continue to break up during the
afternoon and into the evening. Clouds are expected to build into
the region from the W tonight ahead of the s/w. Have trended twd
a compromise of guidance for wrn portions of the CWA and twd the
cooler guidance for ern portions. Latest guidance suggests FG will
develop late tonight impacting srn and ern portions of the CWA
where radiational cooling will be greatest.
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 309 PM CDT Tue Sep 16 2014
(Wednesday through Friday)
Main concern continues to be rain chances tomorrow into tomorrow
night over mainly central and southeast Missouri. GFS/NAM/ECMWF are
still in relatively good agreement in dropping a weak shortwave
trough across Missouri during the day tomorrow. Each of these
models shows some weak low level moisture lingering across central
and southeast Missouri into Wednesday night, so will continue a
chance of showers and thunderstorms in this area. This scenario is
depicted pretty well at least through 00Z by the reflectivity on the
NSSL WRF. Thereafter will maintain a dry forecast Thursday and
Friday as a surface ridge moves across the area at the same time a
upper ridge builds in from the west.
Went on the cooler side of guidance for highs the next couple of
days given the easterly surface flow and it matches up better with
mixing down the 900mb temperatures. Likewise followed the cooler
NAM MOS for lows.
(Saturday through next Tuesday)
While there is still some disagreement between the GFS/ECMWF
regarding the speed and depth of a trough that will pass through the
area this weekend, it still appears that the attendant cold front
will move through on Saturday night and early Sunday. Will keep
chances of showers and thunderstorms going Saturday into Sunday.
Will keep Monday and Tuesday dry at this point as we will be on the
back side of the the upper trough, though the latest runs of the GFS
is showing a secondary through dropping down in the northwesterly
flow on Tuesday. This is a new trend that the ECMWF is not
showing. Still expect at or just above normal temperatures ahead of
the front on Saturday before they drop back below normal for early
next week given expected 850mb temperatures in the 6-9C
range.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1104 PM CDT Tue Sep 16 2014
Northwest flow aloft will keep the mid Fall like conditions in
place. Upper air wave will move through overnight to reinforce the
northwest flow. Models trying to generate precitation at the nose
of a low level (5000 ft) jet of 30 knots over the MO/KS border. So
far no sign of anything develping. COU looks to be the only
location with a shot at rain, but will keep them dry for now. Band
of 4k to 5k clouds rapidly advancing SE. That may put a stop to
any MVFR ceilings. Lower clouds over southern MO are slowly
expanding a bit to the north. Some fog at SUS and CPS will will
bring temporary MVFR conditions until the clouds arrive. Wednesday
looks to be VFR.
Specifics for KSTL: 4k to 5k deck should arrive from 08 to 09z.
Will go with that and hold off on any MVFR ceilings. Lower clouds
over south central MO may work their way north and the MAV
guiidance brings them in for a short time. Not that confident they
will arrive, so will leave out for now.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
848 PM MDT THU SEP 18 2014
.UPDATE...
LOW AMPLITUDE TROUGH AND ASSOCIATED SHORT WAVE ACTIVITY RIDING
ALONG A PLUME OF PACIFIC/SUBTROPICAL MOISTURE HAS RESULTED IN A
RAINY EVENING ACROSS MUCH OF OUR FORECAST AREA THIS EVENING. STILL
LIGHTNING UPSTREAM IN NW WYOMING AND SOUTHERN IDAHO. TRAJECTORY
MOVES MUCH OF THIS ACROSS OUR SOUTH AND EAST OVERNIGHT. I HAVE
ADJUSTED POPS TO ACCOUNT FOR THESE EXPECTATIONS...KEEPING HIGHEST
POPS MAINLY EAST OF A RED LODGE TO HYSHAM LINE OVERNIGHT.
BILLINGS STILL HAS A CHANCE OF ANOTHER SURGE...BUT GENERALLY
LOOKS LIKE IT WILL STAY SOUTH OF CITY OVERNIGHT. BT
&&
.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
EARLY 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 EVENING...AND WILL CONTINUE INTO TONIGHT...WITH MVFR
TO IFR CONDITIONS EXPECTED WITH THE THUNDERSTORMS. OBSCURATION
OVER AREA MOUNTAINS WILL CLEAR OVERNIGHT. 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
41/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
31/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
71/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
82/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
62/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
62/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
52/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 HASTINGS NE
1250 PM CDT WED SEP 17 2014
.UPDATE...
ISSUED AT 705 AM CDT WED SEP 17 2014
SURE ENOUGH...LOCALLY DENSE FOG HAS GRADUALLY SHOWN ITS HAND
ACROSS MAINLY OUR NORTH CENTRAL KS ZONES...ALONG WITH PRIMARILY
OUR WESTERN-MOST COLUMN OF SOUTH CENTRAL NEBRASKA COUNTIES.
ALTHOUGH GROUND-TRUTH IS LIMITED...IT SEEMS THAT COUNTIES WITHIN
OUR CWA ARE MAINLY ON THE FRINGES OF MORE WIDESPREAD DENSE FOG
ISSUES MAINLY AFFECTING WESTERN NEB AND NORTHWEST KS. AS A
RESULT...HAVE OPTED AGAINST A FORMAL DENSE FOG ADVISORY AT THIS
TIME...BUT DID RECENTLY ISSUE A SPECIAL WEATHER STATEMENT TO
HEIGHTEN AWARENESS. IF CONDITIONS CONTINUE TO DETERIORATE THE
ONCOMING DAY SHIFT MAY HAVE TO CONSIDER A SHORT-FUSE ADVISORY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM CDT WED SEP 17 2014
THE MAIN FORECAST ISSUES DURING THESE NEXT 24 HOURS CONSIST
OF...FIRSTLY: WHETHER OR NOT POTENTIALLY IMPACTFUL FOG WILL YET
DEVELOP THIS MORNING AND IF SO...WILL IT REMAIN MOSTLY HIT-AND-
MISS OR BECOME MORE WIDESPREAD IN SOME AREAS. SECONDLY: WILL AT
LEAST ISOLATED THUNDERSTORMS FLARE UP THIS EVENING AND ESPECIALLY
LATE TONIGHT...AND IF SO COULD A FEW EVEN BECOME STRONG TO
MARGINALLY SEVERE. THIRDLY: ALTHOUGH STEADIER SURFACE BREEZES
SHOULD ACT AGAINST FOG FORMATION A BIT MORE SO ON WEDNESDAY NIGHT
VERSUS THIS MORNING...AT LEAST PATCHY DEVELOPMENT AGAIN APPEARS
POSSIBLE AS LOW LEVEL MOISTURE AGAIN KICKS UP ANOTHER NOTCH.
TEMP-WISE...ASSUMING NO UNEXPECTED ENHANCED CLOUD ISSUES...BY FAR
THE BIG STORY IS THAT HIGHS TODAY ARE FORECAST TO BREACH THE 80+
MARK NEARLY CWA-WIDE...IN MANY PLACES FOR THE FIRST TIME IN 9
DAYS SINCE SEP. 8TH...A PRETTY NOTABLE STRETCH CONSIDERING MOST OF
IT OCCURRED DURING THE FIRST HALF OF SEPTEMBER.
STARTING WITH THE HERE AND NOW AS OF 0830Z/330 AM...OVERALL
ANOTHER VERY QUIET NIGHT ACROSS THE CWA...AS ANY WINDOW OF
OPPORTUNITY FOR ELEVATED CONVECTION IN SOUTHEAST ZONES HAS ALL
BUT PASSED BY...AS SEVERAL MODELS CORRECTLY SUGGESTED THAT THIS
ACTIVITY WOULD INITIATE AND FOCUS AT LEAST A FEW COUNTIES OUTSIDE
THE AREA OVER EASTERN KS/WESTERN MO AND THIS IN FACT HAS BEEN THE
CASE. MEANWHILE...11-3.9 MICRON SATELLITE IMAGERY REVEALS NEARLY
CLOUD-FREE SKIES OVER THE CWA...ALTHOUGH A RECENTLY FORMED RIBBON
OF LOW STRATUS RACING NORTH OUT OF CENTRAL KS TOWARD SOUTHEAST NEB
APPEARS POISED TO POSSIBLY BARELY BRUSH OUR EXTREME SOUTHEAST
ZONES AS IT TRACKS NORTH-NORTHEAST. AT THE SURFACE...A RATHER
DISORGANIZED VERY LIGHT/VARIABLE WIND REGIME IS IN PLACE OVER THE
CWA...AS THE LOCAL AREA LIES WELL TO THE WEST OF THE PRIMARY RIDGE
AXIS OVER THE IL/IN AREA...AND JUST TO THE NORTH OF A VERY WEAK
LOW AND TROUGH AXIS OVER SOUTHWEST KS. AS SUSPECTED 24 HOURS
AGO...THE COMBO OF MAINLY CLEAR SKIES/LIGHT BREEZES HAS FOSTERED
AT LEAST SOME LIMITED FOG DEVELOPMENT...BUT BASED ON AUTOMATED
AIRPORT OBS AT LEAST SO FAR ANY FOG HAS BEEN PRETTY HIT AND MISS
IN NATURE AND LIKELY FAVORING TYPICAL LOW LYING AREAS VERSUS MORE
WIDESPREAD. THAT BEING SAID...A FEW AUTOMATED WITHIN OR VERY NEAR
THE CWA HAVE AT LEAST BRIEFLY REPORTED VISIBILITY UNDER 1
MILE...INCLUDING A LOCALIZED QUARTER MILE AT ORD. AS FOR LOW TEMPS
THIS MORNING...PARTS OF ESPECIALLY THE NORTHWEST HALF OF THE CWA
ARE HEADING TOWARD LOWS A FEW DEGREES COOLER THAN EXPECTED AS A
FEW SPOTS HAVE EVEN DIPPED INTO THE UPPER 40S...WHILE MUCH OF THE
SOUTHEAST HALF OF THE CWA SHOULD BOTTOM OUT LOW-MID 50S AND EVEN
CLOSER TO 60 FAR SOUTH. IN THE MID-UPPER LEVEL PICTURE...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM FAIRLY STEADY-
STATE NORTHWESTERLY FLOW OVER THE CENTRAL PLAINS...DIRECTED
BETWEEN A LARGE SCALE WESTERN CONUS RIDGE AND EASTERN CANADA
TROUGH. WELL TO THE SOUTHWEST...WEAKENING TROPICAL STORM ODILE IS
IN THE PROCESS OF SHIFTING OUT OF THE BAJA AREA TOWARD SOUTHERN
AZ. CLOSER TO HOME...A LOW AMPLITUDE DISTURBANCE ZIPPING SOUTHEAST
OVER THE NEB/IA/SD BORDER AREA TOWARD NORTHERN MO HAS HELPED
STRENGTHEN A WEST-SOUTHWESTERLY LOW LEVEL JET MAINLY OVER
KS...AND ITS NO COINCIDENCE THAT ITS EXIT REGION INTO THE KS/MO
BORDER REGION IS WHERE THE INCREASINGLY ACTIVE BAND OF MORNING
ELEVATED CONVECTION HAS FIRED UP.
LOOKING AHEAD AND NOW AND STARTING WITH THESE NEXT FEW HOURS
THROUGH AROUND SUNRISE...OBVIOUSLY FOG TRENDS ARE THE MAIN
CONCERN. ALTHOUGH FOG IS OFTEN A VERY FICKLE ENTITY...VERY SHORT
TERM VISIBILITY PROGS FROM THE RAP13 AND HRRR SUGGEST THAT THINGS
COULD CERTAINLY WORSEN/BECOME MORE WIDESPREAD YET THIS MORNING
PRIMARILY IN WESTERN AND SOUTHERN PORTIONS OF THE CWA...BUT MAYBE
ON A LOCALIZED BASIS ALMOST ANYWHERE. THINGS WOULD HAVE TO GET
CONSIDERABLE WORSE/WIDESPREAD TO EVEN BEGIN TO CONSIDER ANY KIND
OF FORMAL ADVISORY...BUT IT WILL LIKELY BE AT LEAST 14-15Z/9-10AM
BEFORE WE ARE COMPLETELY OUT OF THE WOODS ON SOME AREAS SEEING
VISIBILITIES NEAR/BELOW 1 MILE AND LOCALLY DENSE. THE BOTTOM LINE:
A MIX OF PATCHY FOG AND AREAS-OF FOG WORDING REMAINS IN THE
FORECAST FOR A FEW HOURS PAST SUNRISE...AND THESE TRENDS WILL BE
CLOSELY MONITORED.
GETTING BEYOND ANY MORNING FOG CONCERNS TO THE HEART OF THE
DAYTIME PERIOD...THE MAIN THEME HERE IS DRY CONDITIONS PERSISTING
IN THE PRESENCE OF NOTABLY WARMER CONDITIONS THAN OBSERVED LATELY.
IN THE MID-UPPER LEVELS...FAIRLY CONSISTENT AND LARGELY UNEVENTFUL
NORTHWESTERLY FLOW WILL CONTINUE OVER THE CENTRAL PLAINS AS THE
AFOREMENTIONED SUBTLE DISTURBANCE CURRENTLY JUST NORTHEAST OF THE
CWA DEPARTS WELL SOUTHEAST INTO THE OH VALLEY AREA BY DAYS END.
GIVEN THE LACK OF PERCEPTIBLE FORCING...CONFIDENCE IS RATHER HIGH
IN A DRY-DAY CWA-WIDE AS NEARLY ALL MODEL QPF AND REFLECTIVITY
FIELDS SUGGEST...AS ANY APPRECIABLE CONVECTIVE INSTABILITY THAT
MIGHT MANAGE TO BUILD SHOULD REMAIN CAPPED PER NAM FORECAST
SOUNDINGS. AT THE SURFACE...THE VERY LIGHT/VARIABLE BREEZES OF
THIS MORNING SHOULD GRADUALLY GIVE WAY TO PREVAILING EAST-
SOUTHEAST WINDS ONLY AROUND 10 MPH IN RESPONSE TO WEAK HIGH PLAINS
PRESSURE FALLS TO THE WEST. ONCE ANY MORNING LOWER STRATUS/FOG
THAT DEVELOPS BURNS OFF...SKIES SHOULD AVERAGE NO WORSE THAN
PARTLY CLOUDY DESPITE A FEW PASSING BATCHES OF MID-HIGH
CLOUDS...IN OTHER WORDS NO PESKY LOWER DAYTIME STRATUS DECK
ENVELOPING MUCH OF THE CWA DURING PEAK HEATING AS DID IN FACT
OCCUR YESTERDAY. THE OBVIOUS RESULT SHOULD BE A NOTICEABLE RISE
IN TEMPS VERSUS LATELY. THAT BEING SAID...DID NUDGE HIGHS DOWN
1-2 DEGREES FROM PREVIOUS FCST MAINLY ACROSS THE SOUTHERN CWA
WHILE LEAVING MUCH OF THE NORTH UNCHANGED. THE NET RESULT IS LOW
80S ACROSS MOST CENTRAL/NORTHEAST ZONES AND MAINLY MID 80S
SOUTHWEST WITH UPPER 80S MOST FAVORED IN FAR SOUTHWEST COUNTIES
SUCH AS ROOKS. THE AIRMASS WILL ALSO GET ANOTHER BOOST IN THE
HUMIDITY DEPARTMENT AS DEWPOINTS RISE INTO AT LEAST THE LOW 60S
MOST AREAS FOR THIS AFTERNOON.
TURNING TO THIS EVENING TONIGHT...THE BEST WAY TO DESCRIBE THINGS
IS THAT IT COULD BE A FAIRLY ACTIVE NIGHT IN PARTS OF THE CWA WITH
AT LEAST LIMITED STRONG THUNDERSTORM DEVELOPMENT AND AT LEAST
LIMITED FOG DEVELOPMENT...OR IT COULD ALMOST JUST AS EASILY BE
ANOTHER FAIRLY UNEVENTFUL NIGHT. SUCH IS THE FICKLE NATURE OF
NORTHWESTERLY-FLOW-ALOFT SITUATIONS WHEN LARGE-SCALE FORCING
REMAINS WEAK. SPEAKING OF THE MID-UPPER LEVELS...THE NORTHWESTERLY
FLOW PERSISTS BUT ACTUALLY MIGHT WEAKEN VERY SLIGHTLY AS THE MAIN
RIDGE AXIS ALIGNED OVER THE ROCKIES EDGES EVER SO SLIGHTLY FARTHER
EAST. THERE WILL UNDOUBTEDLY BE AT LEAST 1 OR 2 VERY LOW AMPLITUDE
DISTURBANCES WORKING SOUTHEASTWARD OVER/NEAR THE CWA TONIGHT...AND
COMPARED TO THIS MORNING THIS TIME AROUND IT APPEARS THERE WILL BE
MORE PRONOUNCED LOW-MID LEVEL CONVERGENCE OVER ESPECIALLY THE
SOUTHWESTERN 1/2 OF THE CWA TONIGHT AS NOTED IN 315K ISENTROPIC
SURFACE FORECASTS AND ALSO NOTED IN THE MORE WESTERLY FLOW AND
RESULTANT ELEVATED THETA-E ADVECTION BASED MAINLY IN THE 800-700MB
LAYER. PER VARIOUS DETERMINISTIC AND HIGHER-RES REFLECTIVITY MODEL
SOLUTIONS...AT LEAST A FEW THUNDERSTORMS ARE EXPECTED TO FLARE UP
ALONG THIS ELEVATED CONVERGENCE ZONE...WITH THE GREATEST
LIKELIHOOD WITHIN THE SOUTHWESTERN 1/2 OF THE CWA AFTER MIDNIGHT.
THAT BEING SAID...STORMS CANNOT BE COMPLETELY BE RULED OUT BEFORE
MIDNIGHT EITHER AND HAVE MAINTAINED SOME 20 POPS IN SOUTHWESTERN
AREAS DURING THE EVENING WHILE EXPANDING AT LEAST 20 POPS TO ALL
AREAS AFTER MIDNIGHT BUT FOCUSING HIGHEST 30S IN SOUTHERN ZONES.
SHOULD CONVECTION MATERIALIZE...CERTAINLY A FEW STRONG STORMS
CAPABLE OF PRODUCING HAIL TO AT LEAST NICKEL SIZE OR SLIGHTLY
LARGER CANNOT BE RULED OUT GIVEN ELEVATED CAPE OF 1000-1500 J/KG
IN THE PRESENCE OF AROUND 40KT OF DEEP LAYER SHEAR. MEANWHILE AT
THE SURFACE...FAIRLY LIGHT BUT STEADY EASTERLY BREEZES GENERALLY
5-10 MPH SHOULD PERSIST OVERNIGHT...WHICH SHOULD HELP WORK AGAINST
ANY WIDESPREAD/IMPACTFUL FOG FORMATION...ALONG WITH OF COURSE ANY
LOCALIZED MIXING FROM CONVECTIVE ACTIVITY. THAT BEING SAID...AT
LEAST PATCHY LIGHT FOG CERTAINLY CANNOT BE RULED OUT IN THE MOIST
EASTERLY FLOW...SO HAVE INTRODUCED PATCHY FOG TO THE LATE NIGHT
FORECAST. THE EARLIER 00Z NAM SUGGESTED THAT POTENTIALLY
WIDESPREAD LOW STRATUS AND POSSIBLE LIGHT DRIZZLE COULD
MATERIALIZE AS WELL...BUT THE LATEST 06Z NAM SUGGESTS THAT LOW
LEVEL MOISTURE DEPTH WILL LIKELY REMAIN INSUFFICIENT FOR DRIZZLE
PRODUCTION. MADE VERY LITTLE ALTERATION TO LOW TEMPERATURES...AS
ANOTHER UPWARD CLIMB FROM ONE NIGHT TO THE NEXT CONTINUES...WITH
LOWS AIMED FROM THE UPPER 50S NORTH...LOW 60S CENTRAL AND MID 60S
SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED SEP 17 2014
SUMMARY...FRIDAY...WITH HIGHS IN THE MID 80S...STILL APPEARS TO THE
BE THE WARMEST DAY OF THE NEXT 7 DAYS FOR MOST AREAS...ALTHOUGH IT
WILL NOT BE ALL THAT MUCH WARMER THAN TODAY. RAIN CHANCES IN THE
EXTENDED PERIOD ARE NOT THAT GOOD AND CHANCES HAVE EVEN FALLEN OFF A
LITTLE BIT DURING THE PERIODS WHERE 24HRS EARLIER THEY LOOKING THE
BEST...FRIDAY NIGHT INTO SATURDAY. OVERALL IT WILL BE A FAIRLY
TYPICAL MID SEPTEMBER PERIOD WITH HIGHS ON MOST DAYS AVERAGING OUT
IN THE 70S TO AROUND 80.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES SHOULD DECREASE. THERE IS
WEAK ISENTROPIC LIFT IN THE LOWEST LAYER FROM AROUND AND BELOW 850
MB AND FORECAST MODELS INDICATE THAT A LOW STRATUS DECK COULD
PERSIST THROUGH MUCH OF THE DAY. INITIALLY THIS STRATUS DECK MAY BE
LOW ENOUGH TO BE FOG RIGHT AFTER SUNRISE. SOME FORECAST MODELS ARE
TRYING TO GENERATE A HUNDREDTH OR TWO OF SPLOTCHY QPF. TYPICALLY
THIS COULD BE SPRINKLES...DRIZZLE...OR EVEN ISOLATED THUNDERSTORMS.
IN THIS CASE THE FORECAST SOUNDINGS INDICATE THAT THE SATURATED
STRATUS DECK WILL BE BELOW 850 MB AND NOT THICK ENOUGH TO PRODUCE
DRIZZLE. THERE COULD BE SOME CLOUD SEEDING FROM PASSING MID CLOUDS
GENERATING A FEW SPRINKLES...BUT MOST AREAS WILL BE DRY. THERE IS
SOME WEAK INSTABILITY SO WE CAN NOT RULE OUT THUNDERSTORMS...BUT
ODDS OF THUNDER ARE LOW ENOUGH TO CONTINUE TO KEEP IT OUT OF THE
FORECAST FOR NOW. THE STRATUS DECK WILL KEEP TEMPERATURES DOWN
ESPECIALLY ACROSS NEBRASKA ZONES WHERE STRATUS WILL LIKELY LINGER
LONGER. HIGHS WILL RANGE FROM THE MID 70S IN THE TRI CITIES TO THE
MID 80S ACROSS OUR SOUTHWEST KANSAS COUNTIES.
THURSDAY NIGHT INTO FRIDAY AFTERNOON...THERE IS GOOD AGREEMENT IN
NUMEROUS FORECAST MODELS AND MODEL BLENDS THAT THIS WILL BE A DRY
PERIOD ACROSS OUR FORECAST AREA. THE REMNANTS OF HURRICANE ODILE WILL
BE HEADING NORTHEAST INTO THE TEXAS PANHANDLE AND POSSIBLY INTO FAR
SOUTHWEST KANSAS BY FRIDAY AFTERNOON...BUT STILL OUTSIDE OF OUR
FORECAST AREA. AN UPPER TROUGH COMING OUT OF THE NORTHERN STREAM
WILL BE BREAKING OFF A VORT MAX OVER CALIFORNIA RESULTING IN A LESS
VIGOROUS WAVE FOR OUR FORECAST AREA THAN WAS INDICATED IN MODEL RUNS
24HRS AGO.
FRIDAY NIGHT INTO SATURDAY...THE UPPER TROUGH SWINGING THROUGH THE
PLAINS IS LOOKING LESS IMPRESSIVE WITH RECENT FORECAST RUNS AS SOME
OF THE ENERGY IS BEING LEFT BEHIND OVER CALIFORNIA WHERE IT LEAVES
BEHIND A CUT OFF LOW. MODEL BLENDS HAVE REDUCED POPS SOME IN THIS
PERIOD...AND IT SEEMS JUSTIFIED GIVEN THE SYNOPTIC SITUATION. WILL
HAVE TO REALLY KEEP AN EYE ON THE REMNANTS OF ODILE DURING THIS
PERIOD AS THE REMAINING VORT MAX AND MOISTURE WILL BE COMING UP
THROUGH KANSAS AND MIGHT BE FAR ENOUGH NORTH TO IMPACT OUR CWA.
HOWEVER...THE BETTER BET AT THIS TIME FOR ODILE RELATED
MOISTURE/RAINFALL WILL BE JUST TO THE SOUTH OF OUR FORECAST AREA.
SUNDAY THROUGH TUESDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH GENERALLY DRY WEATHER LIKELY FOR OUR FORECAST
AREA. CAN NOT COMPLETELY RULE OUT A SHORT WAVE SLIDING DOWN INTO OUR
FORECAST AREA ON THE EAST SIDE OF THE RIDGE BY TUESDAY...BUT MOST
AREAS APPEAR DRY AT THIS TIME. HIGH TEMPERATURES WILL BE NEAR NORMAL
AVERAGING OUT IN THE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM CDT WED SEP 17 2014
SKIES WILL BE MAINLY CLEAR TO START THE TAF PERIOD HOWEVER
OVERNIGHT...WITH AN INCREASE IN LLVL MOISTURE LOW CLOUDS WILL
INCREASE/THICKEN WITH LIFR CONDITIONS POSSIBLE. THE POTENTIAL ALSO
EXISTS FOR RESTRICTED VSBYS IN BR/FOG LATE TONIGHT WHICH WILL
LINGER INTO THURSDAY MORNING. VSBYS ARE EXPECTED TO IMPROVE MID
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
705 AM CDT WED SEP 17 2014
.UPDATE...
ISSUED AT 705 AM CDT WED SEP 17 2014
SURE ENOUGH...LOCALLY DENSE FOG HAS GRADUALLY SHOWN ITS HAND
ACROSS MAINLY OUR NORTH CENTRAL KS ZONES...ALONG WITH PRIMARILY
OUR WESTERN-MOST COLUMN OF SOUTH CENTRAL NEBRASKA COUNTIES.
ALTHOUGH GROUND-TRUTH IS LIMITED...IT SEEMS THAT COUNTIES WITHIN
OUR CWA ARE MAINLY ON THE FRINGES OF MORE WIDESPREAD DENSE FOG
ISSUES MAINLY AFFECTING WESTERN NEB AND NORTHWEST KS. AS A
RESULT...HAVE OPTED AGAINST A FORMAL DENSE FOG ADVISORY AT THIS
TIME...BUT DID RECENTLY ISSUE A SPECIAL WEATHER STATEMENT TO
HEIGHTEN AWARENESS. IF CONDITIONS CONTINUE TO DETERIORATE THE
ONCOMING DAY SHIFT MAY HAVE TO CONSIDER A SHORT-FUSE ADVISORY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM CDT WED SEP 17 2014
THE MAIN FORECAST ISSUES DURING THESE NEXT 24 HOURS CONSIST
OF...FIRSTLY: WHETHER OR NOT POTENTIALLY IMPACTFUL FOG WILL YET
DEVELOP THIS MORNING AND IF SO...WILL IT REMAIN MOSTLY HIT-AND-
MISS OR BECOME MORE WIDESPREAD IN SOME AREAS. SECONDLY: WILL AT
LEAST ISOLATED THUNDERSTORMS FLARE UP THIS EVENING AND ESPECIALLY
LATE TONIGHT...AND IF SO COULD A FEW EVEN BECOME STRONG TO
MARGINALLY SEVERE. THIRDLY: ALTHOUGH STEADIER SURFACE BREEZES
SHOULD ACT AGAINST FOG FORMATION A BIT MORE SO ON WEDNESDAY NIGHT
VERSUS THIS MORNING...AT LEAST PATCHY DEVELOPMENT AGAIN APPEARS
POSSIBLE AS LOW LEVEL MOISTURE AGAIN KICKS UP ANOTHER NOTCH.
TEMP-WISE...ASSUMING NO UNEXPECTED ENHANCED CLOUD ISSUES...BY FAR
THE BIG STORY IS THAT HIGHS TODAY ARE FORECAST TO BREACH THE 80+
MARK NEARLY CWA-WIDE...IN MANY PLACES FOR THE FIRST TIME IN 9
DAYS SINCE SEP. 8TH...A PRETTY NOTABLE STRETCH CONSIDERING MOST OF
IT OCCURRED DURING THE FIRST HALF OF SEPTEMBER.
STARTING WITH THE HERE AND NOW AS OF 0830Z/330 AM...OVERALL
ANOTHER VERY QUIET NIGHT ACROSS THE CWA...AS ANY WINDOW OF
OPPORTUNITY FOR ELEVATED CONVECTION IN SOUTHEAST ZONES HAS ALL
BUT PASSED BY...AS SEVERAL MODELS CORRECTLY SUGGESTED THAT THIS
ACTIVITY WOULD INITIATE AND FOCUS AT LEAST A FEW COUNTIES OUTSIDE
THE AREA OVER EASTERN KS/WESTERN MO AND THIS IN FACT HAS BEEN THE
CASE. MEANWHILE...11-3.9 MICRON SATELLITE IMAGERY REVEALS NEARLY
CLOUD-FREE SKIES OVER THE CWA...ALTHOUGH A RECENTLY FORMED RIBBON
OF LOW STRATUS RACING NORTH OUT OF CENTRAL KS TOWARD SOUTHEAST NEB
APPEARS POISED TO POSSIBLY BARELY BRUSH OUR EXTREME SOUTHEAST
ZONES AS IT TRACKS NORTH-NORTHEAST. AT THE SURFACE...A RATHER
DISORGANIZED VERY LIGHT/VARIABLE WIND REGIME IS IN PLACE OVER THE
CWA...AS THE LOCAL AREA LIES WELL TO THE WEST OF THE PRIMARY RIDGE
AXIS OVER THE IL/IN AREA...AND JUST TO THE NORTH OF A VERY WEAK
LOW AND TROUGH AXIS OVER SOUTHWEST KS. AS SUSPECTED 24 HOURS
AGO...THE COMBO OF MAINLY CLEAR SKIES/LIGHT BREEZES HAS FOSTERED
AT LEAST SOME LIMITED FOG DEVELOPMENT...BUT BASED ON AUTOMATED
AIRPORT OBS AT LEAST SO FAR ANY FOG HAS BEEN PRETTY HIT AND MISS
IN NATURE AND LIKELY FAVORING TYPICAL LOW LYING AREAS VERSUS MORE
WIDESPREAD. THAT BEING SAID...A FEW AUTOMATED WITHIN OR VERY NEAR
THE CWA HAVE AT LEAST BRIEFLY REPORTED VISIBILITY UNDER 1
MILE...INCLUDING A LOCALIZED QUARTER MILE AT ORD. AS FOR LOW TEMPS
THIS MORNING...PARTS OF ESPECIALLY THE NORTHWEST HALF OF THE CWA
ARE HEADING TOWARD LOWS A FEW DEGREES COOLER THAN EXPECTED AS A
FEW SPOTS HAVE EVEN DIPPED INTO THE UPPER 40S...WHILE MUCH OF THE
SOUTHEAST HALF OF THE CWA SHOULD BOTTOM OUT LOW-MID 50S AND EVEN
CLOSER TO 60 FAR SOUTH. IN THE MID-UPPER LEVEL PICTURE...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM FAIRLY STEADY-
STATE NORTHWESTERLY FLOW OVER THE CENTRAL PLAINS...DIRECTED
BETWEEN A LARGE SCALE WESTERN CONUS RIDGE AND EASTERN CANADA
TROUGH. WELL TO THE SOUTHWEST...WEAKENING TROPICAL STORM ODILE IS
IN THE PROCESS OF SHIFTING OUT OF THE BAJA AREA TOWARD SOUTHERN
AZ. CLOSER TO HOME...A LOW AMPLITUDE DISTURBANCE ZIPPING SOUTHEAST
OVER THE NEB/IA/SD BORDER AREA TOWARD NORTHERN MO HAS HELPED
STRENGTHEN A WEST-SOUTHWESTERLY LOW LEVEL JET MAINLY OVER
KS...AND ITS NO COINCIDENCE THAT ITS EXIT REGION INTO THE KS/MO
BORDER REGION IS WHERE THE INCREASINGLY ACTIVE BAND OF MORNING
ELEVATED CONVECTION HAS FIRED UP.
LOOKING AHEAD AND NOW AND STARTING WITH THESE NEXT FEW HOURS
THROUGH AROUND SUNRISE...OBVIOUSLY FOG TRENDS ARE THE MAIN
CONCERN. ALTHOUGH FOG IS OFTEN A VERY FICKLE ENTITY...VERY SHORT
TERM VISIBILITY PROGS FROM THE RAP13 AND HRRR SUGGEST THAT THINGS
COULD CERTAINLY WORSEN/BECOME MORE WIDESPREAD YET THIS MORNING
PRIMARILY IN WESTERN AND SOUTHERN PORTIONS OF THE CWA...BUT MAYBE
ON A LOCALIZED BASIS ALMOST ANYWHERE. THINGS WOULD HAVE TO GET
CONSIDERABLE WORSE/WIDESPREAD TO EVEN BEGIN TO CONSIDER ANY KIND
OF FORMAL ADVISORY...BUT IT WILL LIKELY BE AT LEAST 14-15Z/9-10AM
BEFORE WE ARE COMPLETELY OUT OF THE WOODS ON SOME AREAS SEEING
VISIBILITIES NEAR/BELOW 1 MILE AND LOCALLY DENSE. THE BOTTOM LINE:
A MIX OF PATCHY FOG AND AREAS-OF FOG WORDING REMAINS IN THE
FORECAST FOR A FEW HOURS PAST SUNRISE...AND THESE TRENDS WILL BE
CLOSELY MONITORED.
GETTING BEYOND ANY MORNING FOG CONCERNS TO THE HEART OF THE
DAYTIME PERIOD...THE MAIN THEME HERE IS DRY CONDITIONS PERSISTING
IN THE PRESENCE OF NOTABLY WARMER CONDITIONS THAN OBSERVED LATELY.
IN THE MID-UPPER LEVELS...FAIRLY CONSISTENT AND LARGELY UNEVENTFUL
NORTHWESTERLY FLOW WILL CONTINUE OVER THE CENTRAL PLAINS AS THE
AFOREMENTIONED SUBTLE DISTURBANCE CURRENTLY JUST NORTHEAST OF THE
CWA DEPARTS WELL SOUTHEAST INTO THE OH VALLEY AREA BY DAYS END.
GIVEN THE LACK OF PERCEPTIBLE FORCING...CONFIDENCE IS RATHER HIGH
IN A DRY-DAY CWA-WIDE AS NEARLY ALL MODEL QPF AND REFLECTIVITY
FIELDS SUGGEST...AS ANY APPRECIABLE CONVECTIVE INSTABILITY THAT
MIGHT MANAGE TO BUILD SHOULD REMAIN CAPPED PER NAM FORECAST
SOUNDINGS. AT THE SURFACE...THE VERY LIGHT/VARIABLE BREEZES OF
THIS MORNING SHOULD GRADUALLY GIVE WAY TO PREVAILING EAST-
SOUTHEAST WINDS ONLY AROUND 10 MPH IN RESPONSE TO WEAK HIGH PLAINS
PRESSURE FALLS TO THE WEST. ONCE ANY MORNING LOWER STRATUS/FOG
THAT DEVELOPS BURNS OFF...SKIES SHOULD AVERAGE NO WORSE THAN
PARTLY CLOUDY DESPITE A FEW PASSING BATCHES OF MID-HIGH
CLOUDS...IN OTHER WORDS NO PESKY LOWER DAYTIME STRATUS DECK
ENVELOPING MUCH OF THE CWA DURING PEAK HEATING AS DID IN FACT
OCCUR YESTERDAY. THE OBVIOUS RESULT SHOULD BE A NOTICEABLE RISE
IN TEMPS VERSUS LATELY. THAT BEING SAID...DID NUDGE HIGHS DOWN
1-2 DEGREES FROM PREVIOUS FCST MAINLY ACROSS THE SOUTHERN CWA
WHILE LEAVING MUCH OF THE NORTH UNCHANGED. THE NET RESULT IS LOW
80S ACROSS MOST CENTRAL/NORTHEAST ZONES AND MAINLY MID 80S
SOUTHWEST WITH UPPER 80S MOST FAVORED IN FAR SOUTHWEST COUNTIES
SUCH AS ROOKS. THE AIRMASS WILL ALSO GET ANOTHER BOOST IN THE
HUMIDITY DEPARTMENT AS DEWPOINTS RISE INTO AT LEAST THE LOW 60S
MOST AREAS FOR THIS AFTERNOON.
TURNING TO THIS EVENING TONIGHT...THE BEST WAY TO DESCRIBE THINGS
IS THAT IT COULD BE A FAIRLY ACTIVE NIGHT IN PARTS OF THE CWA WITH
AT LEAST LIMITED STRONG THUNDERSTORM DEVELOPMENT AND AT LEAST
LIMITED FOG DEVELOPMENT...OR IT COULD ALMOST JUST AS EASILY BE
ANOTHER FAIRLY UNEVENTFUL NIGHT. SUCH IS THE FICKLE NATURE OF
NORTHWESTERLY-FLOW-ALOFT SITUATIONS WHEN LARGE-SCALE FORCING
REMAINS WEAK. SPEAKING OF THE MID-UPPER LEVELS...THE NORTHWESTERLY
FLOW PERSISTS BUT ACTUALLY MIGHT WEAKEN VERY SLIGHTLY AS THE MAIN
RIDGE AXIS ALIGNED OVER THE ROCKIES EDGES EVER SO SLIGHTLY FARTHER
EAST. THERE WILL UNDOUBTEDLY BE AT LEAST 1 OR 2 VERY LOW AMPLITUDE
DISTURBANCES WORKING SOUTHEASTWARD OVER/NEAR THE CWA TONIGHT...AND
COMPARED TO THIS MORNING THIS TIME AROUND IT APPEARS THERE WILL BE
MORE PRONOUNCED LOW-MID LEVEL CONVERGENCE OVER ESPECIALLY THE
SOUTHWESTERN 1/2 OF THE CWA TONIGHT AS NOTED IN 315K ISENTROPIC
SURFACE FORECASTS AND ALSO NOTED IN THE MORE WESTERLY FLOW AND
RESULTANT ELEVATED THETA-E ADVECTION BASED MAINLY IN THE 800-700MB
LAYER. PER VARIOUS DETERMINISTIC AND HIGHER-RES REFLECTIVITY MODEL
SOLUTIONS...AT LEAST A FEW THUNDERSTORMS ARE EXPECTED TO FLARE UP
ALONG THIS ELEVATED CONVERGENCE ZONE...WITH THE GREATEST
LIKELIHOOD WITHIN THE SOUTHWESTERN 1/2 OF THE CWA AFTER MIDNIGHT.
THAT BEING SAID...STORMS CANNOT BE COMPLETELY BE RULED OUT BEFORE
MIDNIGHT EITHER AND HAVE MAINTAINED SOME 20 POPS IN SOUTHWESTERN
AREAS DURING THE EVENING WHILE EXPANDING AT LEAST 20 POPS TO ALL
AREAS AFTER MIDNIGHT BUT FOCUSING HIGHEST 30S IN SOUTHERN ZONES.
SHOULD CONVECTION MATERIALIZE...CERTAINLY A FEW STRONG STORMS
CAPABLE OF PRODUCING HAIL TO AT LEAST NICKEL SIZE OR SLIGHTLY
LARGER CANNOT BE RULED OUT GIVEN ELEVATED CAPE OF 1000-1500 J/KG
IN THE PRESENCE OF AROUND 40KT OF DEEP LAYER SHEAR. MEANWHILE AT
THE SURFACE...FAIRLY LIGHT BUT STEADY EASTERLY BREEZES GENERALLY
5-10 MPH SHOULD PERSIST OVERNIGHT...WHICH SHOULD HELP WORK AGAINST
ANY WIDESPREAD/IMPACTFUL FOG FORMATION...ALONG WITH OF COURSE ANY
LOCALIZED MIXING FROM CONVECTIVE ACTIVITY. THAT BEING SAID...AT
LEAST PATCHY LIGHT FOG CERTAINLY CANNOT BE RULED OUT IN THE MOIST
EASTERLY FLOW...SO HAVE INTRODUCED PATCHY FOG TO THE LATE NIGHT
FORECAST. THE EARLIER 00Z NAM SUGGESTED THAT POTENTIALLY
WIDESPREAD LOW STRATUS AND POSSIBLE LIGHT DRIZZLE COULD
MATERIALIZE AS WELL...BUT THE LATEST 06Z NAM SUGGESTS THAT LOW
LEVEL MOISTURE DEPTH WILL LIKELY REMAIN INSUFFICIENT FOR DRIZZLE
PRODUCTION. MADE VERY LITTLE ALTERATION TO LOW TEMPERATURES...AS
ANOTHER UPWARD CLIMB FROM ONE NIGHT TO THE NEXT CONTINUES...WITH
LOWS AIMED FROM THE UPPER 50S NORTH...LOW 60S CENTRAL AND MID 60S
SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED SEP 17 2014
SUMMARY...FRIDAY...WITH HIGHS IN THE MID 80S...STILL APPEARS TO THE
BE THE WARMEST DAY OF THE NEXT 7 DAYS FOR MOST AREAS...ALTHOUGH IT
WILL NOT BE ALL THAT MUCH WARMER THAN TODAY. RAIN CHANCES IN THE
EXTENDED PERIOD ARE NOT THAT GOOD AND CHANCES HAVE EVEN FALLEN OFF A
LITTLE BIT DURING THE PERIODS WHERE 24HRS EARLIER THEY LOOKING THE
BEST...FRIDAY NIGHT INTO SATURDAY. OVERALL IT WILL BE A FAIRLY
TYPICAL MID SEPTEMBER PERIOD WITH HIGHS ON MOST DAYS AVERAGING OUT
IN THE 70S TO AROUND 80.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES SHOULD DECREASE. THERE IS
WEAK ISENTROPIC LIFT IN THE LOWEST LAYER FROM AROUND AND BELOW 850
MB AND FORECAST MODELS INDICATE THAT A LOW STRATUS DECK COULD
PERSIST THROUGH MUCH OF THE DAY. INITIALLY THIS STRATUS DECK MAY BE
LOW ENOUGH TO BE FOG RIGHT AFTER SUNRISE. SOME FORECAST MODELS ARE
TRYING TO GENERATE A HUNDREDTH OR TWO OF SPLOTCHY QPF. TYPICALLY
THIS COULD BE SPRINKLES...DRIZZLE...OR EVEN ISOLATED THUNDERSTORMS.
IN THIS CASE THE FORECAST SOUNDINGS INDICATE THAT THE SATURATED
STRATUS DECK WILL BE BELOW 850 MB AND NOT THICK ENOUGH TO PRODUCE
DRIZZLE. THERE COULD BE SOME CLOUD SEEDING FROM PASSING MID CLOUDS
GENERATING A FEW SPRINKLES...BUT MOST AREAS WILL BE DRY. THERE IS
SOME WEAK INSTABILITY SO WE CAN NOT RULE OUT THUNDERSTORMS...BUT
ODDS OF THUNDER ARE LOW ENOUGH TO CONTINUE TO KEEP IT OUT OF THE
FORECAST FOR NOW. THE STRATUS DECK WILL KEEP TEMPERATURES DOWN
ESPECIALLY ACROSS NEBRASKA ZONES WHERE STRATUS WILL LIKELY LINGER
LONGER. HIGHS WILL RANGE FROM THE MID 70S IN THE TRI CITIES TO THE
MID 80S ACROSS OUR SOUTHWEST KANSAS COUNTIES.
THURSDAY NIGHT INTO FRIDAY AFTERNOON...THERE IS GOOD AGREEMENT IN
NUMEROUS FORECAST MODELS AND MODEL BLENDS THAT THIS WILL BE A DRY
PERIOD ACROSS OUR FORECAST AREA. THE REMNANTS OF HURRICANE ODILE WILL
BE HEADING NORTHEAST INTO THE TEXAS PANHANDLE AND POSSIBLY INTO FAR
SOUTHWEST KANSAS BY FRIDAY AFTERNOON...BUT STILL OUTSIDE OF OUR
FORECAST AREA. AN UPPER TROUGH COMING OUT OF THE NORTHERN STREAM
WILL BE BREAKING OFF A VORT MAX OVER CALIFORNIA RESULTING IN A LESS
VIGOROUS WAVE FOR OUR FORECAST AREA THAN WAS INDICATED IN MODEL RUNS
24HRS AGO.
FRIDAY NIGHT INTO SATURDAY...THE UPPER TROUGH SWINGING THROUGH THE
PLAINS IS LOOKING LESS IMPRESSIVE WITH RECENT FORECAST RUNS AS SOME
OF THE ENERGY IS BEING LEFT BEHIND OVER CALIFORNIA WHERE IT LEAVES
BEHIND A CUT OFF LOW. MODEL BLENDS HAVE REDUCED POPS SOME IN THIS
PERIOD...AND IT SEEMS JUSTIFIED GIVEN THE SYNOPTIC SITUATION. WILL
HAVE TO REALLY KEEP AN EYE ON THE REMNANTS OF ODILE DURING THIS
PERIOD AS THE REMAINING VORT MAX AND MOISTURE WILL BE COMING UP
THROUGH KANSAS AND MIGHT BE FAR ENOUGH NORTH TO IMPACT OUR CWA.
HOWEVER...THE BETTER BET AT THIS TIME FOR ODILE RELATED
MOISTURE/RAINFALL WILL BE JUST TO THE SOUTH OF OUR FORECAST AREA.
SUNDAY THROUGH TUESDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH GENERALLY DRY WEATHER LIKELY FOR OUR FORECAST
AREA. CAN NOT COMPLETELY RULE OUT A SHORT WAVE SLIDING DOWN INTO OUR
FORECAST AREA ON THE EAST SIDE OF THE RIDGE BY TUESDAY...BUT MOST
AREAS APPEAR DRY AT THIS TIME. HIGH TEMPERATURES WILL BE NEAR NORMAL
AVERAGING OUT IN THE 70S.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH THURSDAY MORNING)
ISSUED AT 700 AM CDT WED SEP 17 2014
ALTHOUGH CONFIDENCE IS FAIRLY HIGH IN VFR CEILING/VISIBILITY
THROUGH THE MIDDLE 12-18 HOURS OF THE VALID PERIOD...THERE IS
QUITE A BIT UNCERTAINTY REGARDING BOTH THE INITIAL FEW HOURS RIGHT
AWAY THIS MORNING...AND THEN AGAIN LATE TONIGHT. IN
ADDITION...THERE IS AT LEAST A LOW RISK FOR SHOWERS/THUNDERSTORMS
AT ONE OR BOTH TERMINALS ESPECIALLY DURING THE OVERNIGHT
HOURS...BUT CONFIDENCE IN OCCURRENCE IS STILL TOO LOW AT THIS TIME
RANGE TO EVEN JUSTIFY A VICINITY THUNDERSTORM (VCTS). STARTING
WITH THE FIRST FEW HOURS THIS MORNING...THERE IS STILL A CHANCE
THAT AT LEAST LIGHT FOG AND OR BRIEF LOW STRATUS COULD MOVE INTO
THE AREA...BUT IT HAS REMAINED AT LEAST SLIGHTLY WEST AND/OR SOUTH
OF THE AREA THUS FAR. GIVEN CONSIDERABLE UNCERTAINTY...WILL RUN A
TEMPO GROUP FOR MVFR VISIBILITY WITH AMENDMENTS VERY POSSIBLE.
ONCE ANY MORNING FOG/STRATUS BURNS...SEVERAL HOURS OF
HIGH-CONFIDENCE VFR COMMENCES. THEN LATE TONIGHT...MOIST EASTERLY
FLOW COULD SPARK ANOTHER ROUND OF STRATUS AND FOG...AND HAVE
INTRODUCED MVFR CATEGORIES IN EACH STARTING AT 08Z. SURFACE
BREEZES SHOULD NOT BE MUCH OF AN ISSUE THROUGH THE PERIOD...WITH
SUSTAINED SPEEDS AVERAGING UNDER 10KT AND FROM AN EAST-SOUTHEAST
DIRECTION THROUGH MOST OF THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
446 AM CDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM CDT WED SEP 17 2014
THE MAIN FORECAST ISSUES DURING THESE NEXT 24 HOURS CONSIST
OF...FIRSTLY: WHETHER OR NOT POTENTIALLY IMPACTFUL FOG WILL YET
DEVELOP THIS MORNING AND IF SO...WILL IT REMAIN MOSTLY HIT-AND-
MISS OR BECOME MORE WIDESPREAD IN SOME AREAS. SECONDLY: WILL AT
LEAST ISOLATED THUNDERSTORMS FLARE UP THIS EVENING AND ESPECIALLY
LATE TONIGHT...AND IF SO COULD A FEW EVEN BECOME STRONG TO
MARGINALLY SEVERE. THIRDLY: ALTHOUGH STEADIER SURFACE BREEZES
SHOULD ACT AGAINST FOG FORMATION A BIT MORE SO ON WEDNESDAY NIGHT
VERSUS THIS MORNING...AT LEAST PATCHY DEVELOPMENT AGAIN APPEARS
POSSIBLE AS LOW LEVEL MOISTURE AGAIN KICKS UP ANOTHER NOTCH.
TEMP-WISE...ASSUMING NO UNEXPECTED ENHANCED CLOUD ISSUES...BY FAR
THE BIG STORY IS THAT HIGHS TODAY ARE FORECAST TO BREACH THE 80+
MARK NEARLY CWA-WIDE...IN MANY PLACES FOR THE FIRST TIME IN 9
DAYS SINCE SEP. 8TH...A PRETTY NOTABLE STRETCH CONSIDERING MOST OF
IT OCCURRED DURING THE FIRST HALF OF SEPTEMBER.
STARTING WITH THE HERE AND NOW AS OF 0830Z/330 AM...OVERALL
ANOTHER VERY QUIET NIGHT ACROSS THE CWA...AS ANY WINDOW OF
OPPORTUNITY FOR ELEVATED CONVECTION IN SOUTHEAST ZONES HAS ALL
BUT PASSED BY...AS SEVERAL MODELS CORRECTLY SUGGESTED THAT THIS
ACTIVITY WOULD INITIATE AND FOCUS AT LEAST A FEW COUNTIES OUTSIDE
THE AREA OVER EASTERN KS/WESTERN MO AND THIS IN FACT HAS BEEN THE
CASE. MEANWHILE...11-3.9 MICRON SATELLITE IMAGERY REVEALS NEARLY
CLOUD-FREE SKIES OVER THE CWA...ALTHOUGH A RECENTLY FORMED RIBBON
OF LOW STRATUS RACING NORTH OUT OF CENTRAL KS TOWARD SOUTHEAST NEB
APPEARS POISED TO POSSIBLY BARELY BRUSH OUR EXTREME SOUTHEAST
ZONES AS IT TRACKS NORTH-NORTHEAST. AT THE SURFACE...A RATHER
DISORGANIZED VERY LIGHT/VARIABLE WIND REGIME IS IN PLACE OVER THE
CWA...AS THE LOCAL AREA LIES WELL TO THE WEST OF THE PRIMARY RIDGE
AXIS OVER THE IL/IN AREA...AND JUST TO THE NORTH OF A VERY WEAK
LOW AND TROUGH AXIS OVER SOUTHWEST KS. AS SUSPECTED 24 HOURS
AGO...THE COMBO OF MAINLY CLEAR SKIES/LIGHT BREEZES HAS FOSTERED
AT LEAST SOME LIMITED FOG DEVELOPMENT...BUT BASED ON AUTOMATED
AIRPORT OBS AT LEAST SO FAR ANY FOG HAS BEEN PRETTY HIT AND MISS
IN NATURE AND LIKELY FAVORING TYPICAL LOW LYING AREAS VERSUS MORE
WIDESPREAD. THAT BEING SAID...A FEW AUTOMATED WITHIN OR VERY NEAR
THE CWA HAVE AT LEAST BRIEFLY REPORTED VISIBILITY UNDER 1
MILE...INCLUDING A LOCALIZED QUARTER MILE AT ORD. AS FOR LOW TEMPS
THIS MORNING...PARTS OF ESPECIALLY THE NORTHWEST HALF OF THE CWA
ARE HEADING TOWARD LOWS A FEW DEGREES COOLER THAN EXPECTED AS A
FEW SPOTS HAVE EVEN DIPPED INTO THE UPPER 40S...WHILE MUCH OF THE
SOUTHEAST HALF OF THE CWA SHOULD BOTTOM OUT LOW-MID 50S AND EVEN
CLOSER TO 60 FAR SOUTH. IN THE MID-UPPER LEVEL PICTURE...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM FAIRLY STEADY-
STATE NORTHWESTERLY FLOW OVER THE CENTRAL PLAINS...DIRECTED
BETWEEN A LARGE SCALE WESTERN CONUS RIDGE AND EASTERN CANADA
TROUGH. WELL TO THE SOUTHWEST...WEAKENING TROPICAL STORM ODILE IS
IN THE PROCESS OF SHIFTING OUT OF THE BAJA AREA TOWARD SOUTHERN
AZ. CLOSER TO HOME...A LOW AMPLITUDE DISTURBANCE ZIPPING SOUTHEAST
OVER THE NEB/IA/SD BORDER AREA TOWARD NORTHERN MO HAS HELPED
STRENGTHEN A WEST-SOUTHWESTERLY LOW LEVEL JET MAINLY OVER
KS...AND ITS NO COINCIDENCE THAT ITS EXIT REGION INTO THE KS/MO
BORDER REGION IS WHERE THE INCREASINGLY ACTIVE BAND OF MORNING
ELEVATED CONVECTION HAS FIRED UP.
LOOKING AHEAD AND NOW AND STARTING WITH THESE NEXT FEW HOURS
THROUGH AROUND SUNRISE...OBVIOUSLY FOG TRENDS ARE THE MAIN
CONCERN. ALTHOUGH FOG IS OFTEN A VERY FICKLE ENTITY...VERY SHORT
TERM VISIBILITY PROGS FROM THE RAP13 AND HRRR SUGGEST THAT THINGS
COULD CERTAINLY WORSEN/BECOME MORE WIDESPREAD YET THIS MORNING
PRIMARILY IN WESTERN AND SOUTHERN PORTIONS OF THE CWA...BUT MAYBE
ON A LOCALIZED BASIS ALMOST ANYWHERE. THINGS WOULD HAVE TO GET
CONSIDERABLE WORSE/WIDESPREAD TO EVEN BEGIN TO CONSIDER ANY KIND
OF FORMAL ADVISORY...BUT IT WILL LIKELY BE AT LEAST 14-15Z/9-10AM
BEFORE WE ARE COMPLETELY OUT OF THE WOODS ON SOME AREAS SEEING
VISIBILITIES NEAR/BELOW 1 MILE AND LOCALLY DENSE. THE BOTTOM LINE:
A MIX OF PATCHY FOG AND AREAS-OF FOG WORDING REMAINS IN THE
FORECAST FOR A FEW HOURS PAST SUNRISE...AND THESE TRENDS WILL BE
CLOSELY MONITORED.
GETTING BEYOND ANY MORNING FOG CONCERNS TO THE HEART OF THE
DAYTIME PERIOD...THE MAIN THEME HERE IS DRY CONDITIONS PERSISTING
IN THE PRESENCE OF NOTABLY WARMER CONDITIONS THAN OBSERVED LATELY.
IN THE MID-UPPER LEVELS...FAIRLY CONSISTENT AND LARGELY UNEVENTFUL
NORTHWESTERLY FLOW WILL CONTINUE OVER THE CENTRAL PLAINS AS THE
AFOREMENTIONED SUBTLE DISTURBANCE CURRENTLY JUST NORTHEAST OF THE
CWA DEPARTS WELL SOUTHEAST INTO THE OH VALLEY AREA BY DAYS END.
GIVEN THE LACK OF PERCEPTIBLE FORCING...CONFIDENCE IS RATHER HIGH
IN A DRY-DAY CWA-WIDE AS NEARLY ALL MODEL QPF AND REFLECTIVITY
FIELDS SUGGEST...AS ANY APPRECIABLE CONVECTIVE INSTABILITY THAT
MIGHT MANAGE TO BUILD SHOULD REMAIN CAPPED PER NAM FORECAST
SOUNDINGS. AT THE SURFACE...THE VERY LIGHT/VARIABLE BREEZES OF
THIS MORNING SHOULD GRADUALLY GIVE WAY TO PREVAILING EAST-
SOUTHEAST WINDS ONLY AROUND 10 MPH IN RESPONSE TO WEAK HIGH PLAINS
PRESSURE FALLS TO THE WEST. ONCE ANY MORNING LOWER STRATUS/FOG
THAT DEVELOPS BURNS OFF...SKIES SHOULD AVERAGE NO WORSE THAN
PARTLY CLOUDY DESPITE A FEW PASSING BATCHES OF MID-HIGH
CLOUDS...IN OTHER WORDS NO PESKY LOWER DAYTIME STRATUS DECK
ENVELOPING MUCH OF THE CWA DURING PEAK HEATING AS DID IN FACT
OCCUR YESTERDAY. THE OBVIOUS RESULT SHOULD BE A NOTICEABLE RISE
IN TEMPS VERSUS LATELY. THAT BEING SAID...DID NUDGE HIGHS DOWN
1-2 DEGREES FROM PREVIOUS FCST MAINLY ACROSS THE SOUTHERN CWA
WHILE LEAVING MUCH OF THE NORTH UNCHANGED. THE NET RESULT IS LOW
80S ACROSS MOST CENTRAL/NORTHEAST ZONES AND MAINLY MID 80S
SOUTHWEST WITH UPPER 80S MOST FAVORED IN FAR SOUTHWEST COUNTIES
SUCH AS ROOKS. THE AIRMASS WILL ALSO GET ANOTHER BOOST IN THE
HUMIDITY DEPARTMENT AS DEWPOINTS RISE INTO AT LEAST THE LOW 60S
MOST AREAS FOR THIS AFTERNOON.
TURNING TO THIS EVENING TONIGHT...THE BEST WAY TO DESCRIBE THINGS
IS THAT IT COULD BE A FAIRLY ACTIVE NIGHT IN PARTS OF THE CWA WITH
AT LEAST LIMITED STRONG THUNDERSTORM DEVELOPMENT AND AT LEAST
LIMITED FOG DEVELOPMENT...OR IT COULD ALMOST JUST AS EASILY BE
ANOTHER FAIRLY UNEVENTFUL NIGHT. SUCH IS THE FICKLE NATURE OF
NORTHWESTERLY-FLOW-ALOFT SITUATIONS WHEN LARGE-SCALE FORCING
REMAINS WEAK. SPEAKING OF THE MID-UPPER LEVELS...THE NORTHWESTERLY
FLOW PERSISTS BUT ACTUALLY MIGHT WEAKEN VERY SLIGHTLY AS THE MAIN
RIDGE AXIS ALIGNED OVER THE ROCKIES EDGES EVER SO SLIGHTLY FARTHER
EAST. THERE WILL UNDOUBTEDLY BE AT LEAST 1 OR 2 VERY LOW AMPLITUDE
DISTURBANCES WORKING SOUTHEASTWARD OVER/NEAR THE CWA TONIGHT...AND
COMPARED TO THIS MORNING THIS TIME AROUND IT APPEARS THERE WILL BE
MORE PRONOUNCED LOW-MID LEVEL CONVERGENCE OVER ESPECIALLY THE
SOUTHWESTERN 1/2 OF THE CWA TONIGHT AS NOTED IN 315K ISENTROPIC
SURFACE FORECASTS AND ALSO NOTED IN THE MORE WESTERLY FLOW AND
RESULTANT ELEVATED THETA-E ADVECTION BASED MAINLY IN THE 800-700MB
LAYER. PER VARIOUS DETERMINISTIC AND HIGHER-RES REFLECTIVITY MODEL
SOLUTIONS...AT LEAST A FEW THUNDERSTORMS ARE EXPECTED TO FLARE UP
ALONG THIS ELEVATED CONVERGENCE ZONE...WITH THE GREATEST
LIKELIHOOD WITHIN THE SOUTHWESTERN 1/2 OF THE CWA AFTER MIDNIGHT.
THAT BEING SAID...STORMS CANNOT BE COMPLETELY BE RULED OUT BEFORE
MIDNIGHT EITHER AND HAVE MAINTAINED SOME 20 POPS IN SOUTHWESTERN
AREAS DURING THE EVENING WHILE EXPANDING AT LEAST 20 POPS TO ALL
AREAS AFTER MIDNIGHT BUT FOCUSING HIGHEST 30S IN SOUTHERN ZONES.
SHOULD CONVECTION MATERIALIZE...CERTAINLY A FEW STRONG STORMS
CAPABLE OF PRODUCING HAIL TO AT LEAST NICKEL SIZE OR SLIGHTLY
LARGER CANNOT BE RULED OUT GIVEN ELEVATED CAPE OF 1000-1500 J/KG
IN THE PRESENCE OF AROUND 40KT OF DEEP LAYER SHEAR. MEANWHILE AT
THE SURFACE...FAIRLY LIGHT BUT STEADY EASTERLY BREEZES GENERALLY
5-10 MPH SHOULD PERSIST OVERNIGHT...WHICH SHOULD HELP WORK AGAINST
ANY WIDESPREAD/IMPACTFUL FOG FORMATION...ALONG WITH OF COURSE ANY
LOCALIZED MIXING FROM CONVECTIVE ACTIVITY. THAT BEING SAID...AT
LEAST PATCHY LIGHT FOG CERTAINLY CANNOT BE RULED OUT IN THE MOIST
EASTERLY FLOW...SO HAVE INTRODUCED PATCHY FOG TO THE LATE NIGHT
FORECAST. THE EARLIER 00Z NAM SUGGESTED THAT POTENTIALLY
WIDESPREAD LOW STRATUS AND POSSIBLE LIGHT DRIZZLE COULD
MATERIALIZE AS WELL...BUT THE LATEST 06Z NAM SUGGESTS THAT LOW
LEVEL MOISTURE DEPTH WILL LIKELY REMAIN INSUFFICIENT FOR DRIZZLE
PRODUCTION. MADE VERY LITTLE ALTERATION TO LOW TEMPERATURES...AS
ANOTHER UPWARD CLIMB FROM ONE NIGHT TO THE NEXT CONTINUES...WITH
LOWS AIMED FROM THE UPPER 50S NORTH...LOW 60S CENTRAL AND MID 60S
SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED SEP 17 2014
SUMMARY...FRIDAY...WITH HIGHS IN THE MID 80S...STILL APPEARS TO THE
BE THE WARMEST DAY OF THE NEXT 7 DAYS FOR MOST AREAS...ALTHOUGH IT
WILL NOT BE ALL THAT MUCH WARMER THAN TODAY. RAIN CHANCES IN THE
EXTENDED PERIOD ARE NOT THAT GOOD AND CHANCES HAVE EVEN FALLEN OFF A
LITTLE BIT DURING THE PERIODS WHERE 24HRS EARLIER THEY LOOKING THE
BEST...FRIDAY NIGHT INTO SATURDAY. OVERALL IT WILL BE A FAIRLY
TYPICAL MID SEPTEMBER PERIOD WITH HIGHS ON MOST DAYS AVERAGING OUT
IN THE 70S TO AROUND 80.
THURSDAY...THE UPPER RIDGE OVER THE ROCKIES WILL SLIDE FURTHER EAST
INTO THE PLAINS AND PRECIPITATION CHANCES SHOULD DECREASE. THERE IS
WEAK ISENTROPIC LIFT IN THE LOWEST LAYER FROM AROUND AND BELOW 850
MB AND FORECAST MODELS INDICATE THAT A LOW STRATUS DECK COULD
PERSIST THROUGH MUCH OF THE DAY. INITIALLY THIS STRATUS DECK MAY BE
LOW ENOUGH TO BE FOG RIGHT AFTER SUNRISE. SOME FORECAST MODELS ARE
TRYING TO GENERATE A HUNDREDTH OR TWO OF SPLOTCHY QPF. TYPICALLY
THIS COULD BE SPRINKLES...DRIZZLE...OR EVEN ISOLATED THUNDERSTORMS.
IN THIS CASE THE FORECAST SOUNDINGS INDICATE THAT THE SATURATED
STRATUS DECK WILL BE BELOW 850 MB AND NOT THICK ENOUGH TO PRODUCE
DRIZZLE. THERE COULD BE SOME CLOUD SEEDING FROM PASSING MID CLOUDS
GENERATING A FEW SPRINKLES...BUT MOST AREAS WILL BE DRY. THERE IS
SOME WEAK INSTABILITY SO WE CAN NOT RULE OUT THUNDERSTORMS...BUT
ODDS OF THUNDER ARE LOW ENOUGH TO CONTINUE TO KEEP IT OUT OF THE
FORECAST FOR NOW. THE STRATUS DECK WILL KEEP TEMPERATURES DOWN
ESPECIALLY ACROSS NEBRASKA ZONES WHERE STRATUS WILL LIKELY LINGER
LONGER. HIGHS WILL RANGE FROM THE MID 70S IN THE TRI CITIES TO THE
MID 80S ACROSS OUR SOUTHWEST KANSAS COUNTIES.
THURSDAY NIGHT INTO FRIDAY AFTERNOON...THERE IS GOOD AGREEMENT IN
NUMEROUS FORECAST MODELS AND MODEL BLENDS THAT THIS WILL BE A DRY
PERIOD ACROSS OUR FORECAST AREA. THE REMNANTS OF HURRICANE ODILE WILL
BE HEADING NORTHEAST INTO THE TEXAS PANHANDLE AND POSSIBLY INTO FAR
SOUTHWEST KANSAS BY FRIDAY AFTERNOON...BUT STILL OUTSIDE OF OUR
FORECAST AREA. AN UPPER TROUGH COMING OUT OF THE NORTHERN STREAM
WILL BE BREAKING OFF A VORT MAX OVER CALIFORNIA RESULTING IN A LESS
VIGOROUS WAVE FOR OUR FORECAST AREA THAN WAS INDICATED IN MODEL RUNS
24HRS AGO.
FRIDAY NIGHT INTO SATURDAY...THE UPPER TROUGH SWINGING THROUGH THE
PLAINS IS LOOKING LESS IMPRESSIVE WITH RECENT FORECAST RUNS AS SOME
OF THE ENERGY IS BEING LEFT BEHIND OVER CALIFORNIA WHERE IT LEAVES
BEHIND A CUT OFF LOW. MODEL BLENDS HAVE REDUCED POPS SOME IN THIS
PERIOD...AND IT SEEMS JUSTIFIED GIVEN THE SYNOPTIC SITUATION. WILL
HAVE TO REALLY KEEP AN EYE ON THE REMNANTS OF ODILE DURING THIS
PERIOD AS THE REMAINING VORT MAX AND MOISTURE WILL BE COMING UP
THROUGH KANSAS AND MIGHT BE FAR ENOUGH NORTH TO IMPACT OUR CWA.
HOWEVER...THE BETTER BET AT THIS TIME FOR ODILE RELATED
MOISTURE/RAINFALL WILL BE JUST TO THE SOUTH OF OUR FORECAST AREA.
SUNDAY THROUGH TUESDAY...UPPER LEVEL RIDGING WILL RESUME ACROSS THE
WESTERN CONUS WITH GENERALLY DRY WEATHER LIKELY FOR OUR FORECAST
AREA. CAN NOT COMPLETELY RULE OUT A SHORT WAVE SLIDING DOWN INTO OUR
FORECAST AREA ON THE EAST SIDE OF THE RIDGE BY TUESDAY...BUT MOST
AREAS APPEAR DRY AT THIS TIME. HIGH TEMPERATURES WILL BE NEAR NORMAL
AVERAGING OUT IN THE 70S.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY)
ISSUED AT 100 AM CDT WED SEP 17 2014
CONFIDENCE IS FAIRLY HIGH IN PREVALENT VFR CEILING/VISIBILITY
THROUGH THE MAJORITY OF THE PERIOD...WITH THE MAIN ISSUE BEING THE
POSSIBILITY OF REDUCED VISIBILITY IN FOG DEVELOPMENT THIS MORNING
MAINLY WITHIN A FEW HOURS EITHER SIDE OF SUNRISE. OPTED TO REMAIN
QUITE CONSISTENT WITH PREVIOUS FORECAST IN DEPICTING A PERIOD OF
PREVAILING MVFR VISIBILITY AT BOTH SITES 10Z-14Z...BUT OF COURSE
THIS IS JUST A BEST STAB AT VISIBILITY...AS CONSIDERABLE
FLUCTUATION ON EITHER SIDE OF THIS RANGE (FROM VFR TO IFR OR
WORSE) CANNOT BE COMPLETELY RULED OUT. AT ANY RATE...ONCE ANY
POSSIBLE MORNING FOG VACATES EXPECT FAIRLY TRANQUIL AVIATION
CONDITIONS THROUGH THE REMAINDER OF THE PERIOD. ANOTHER ROUND OF
AT LEAST LIGHT FOG AND MAYBE SOME STRATUS WITH A HEIGHTENED RISK
FOR A LOW CEILING COULD MATERIALIZE SHORTLY BEYOND THE CURRENT
VALID PERIOD LATE WEDNESDAY NIGHT. AS FOR SHOWER/THUNDERSTORM
POTENTIAL...IT IS ESSENTIALLY NIL THROUGH THE FIRST 18 HOURS OR
SO...BUT THERE IS MAYBE A SMALL CHANCE AT PLAY DURING THE EVENING
HOURS. HOWEVER...THIS CHANCE APPEARS TOO SMALL TO JUSTIFY EVEN A
VICINITY (VCTS) MENTION AT THIS JUNCTURE. SURFACE BREEZES SHOULD
NOT BE MUCH OF AN ISSUE THROUGH THE PERIOD...WITH SUSTAINED SPEEDS
AVERAGING UNDER 10KT AND FROM AN EAST-SOUTHEAST DIRECTION AT MOST
TIMES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
334 AM CDT WED SEP 17 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM CDT WED SEP 17 2014
NORTHWESTERLY FLOW ALOFT CONTINUES OVER THE REGION THIS MORNING AS
AN UPPER LEVEL RIDGE AXIS EXTENDS ACROSS THE ROCKIES. TROPICAL STORM
ODILE CONTINUES TO MOVE ACROSS THE NORTHERN GULF OF CALIFORNIA AND
TOWARD THE SOUTHWESTERN UNITED STATES. AT THE SURFACE...HIGH
PRESSURE HAS MOVED INTO THE EASTERN CONUS WHILE A WARM FRONT
EXTENDS EAST ACROSS KANSAS FROM LOW PRESSURE CENTERED OVER
SOUTHEAST COLORADO/SOUTHWEST KANSAS. LOW LEVEL WARM AIR/THETA-E
ADVECTION TO OUR SOUTH HAS GENERATED ISOLATED SHOWERS AND
THUNDERSTORMS OVER NORTHEAST KANSAS SO WILL KEEP THE SMALL CHANCE
OVER OUR EXTREME SOUTHERN COUNTIES THROUGH THE EARLY MORNING
HOURS. AN AREA OF LOW CLOUDS THAT DEVELOPED LAST EVENING SHOULD
MIX OUT LATER THIS MORNING...ALLOWING SFC TEMPERATURES TO RISE
INTO THE UPPER 70S TO LOW 80S TODAY.
WE HAVE REMOVED THE SMALL POPS THAT HAD BEEN IN OUR SOUTHERN
COUNTIES FOR THIS EVENING DUE TO LACK OF ANY STRONG FORCING
MECHANISM. A MAJORITY OF MODEL SOLUTIONS MAINTAIN A DRY PERIOD
THIS AFTERNOON AND EVENING AS WELL. LOW LEVEL MOIST ADVECTION WILL
CONTINUE THROUGH THE OVERNIGHT HOWEVER. A FEW THUNDERSTORMS COULD
DEVELOP ACROSS NORTHEAST KANSAS NEAR 850MB FRONT AND SPREAD INTO
FAR SOUTHEAST NEBRASKA. WILL CARRY A SMALL POP IN OUR FAR
SOUTHWESTERN CWA AFTER 06Z. FORECAST SOUNDINGS DO INDICATE
POTENTIAL FOR DRIZZLE/FOG OVERNIGHT SO HAVE INCLUDED A MENTION AS
LOW LEVEL MOISTURE STREAMS NORTH.
CLOUDS LOOK SLOW TO MOVE OUT ON THURSDAY WHICH WOULD KEEP HIGHS
ABOUT 5 DEGREES COOLER THAN WEDNESDAY. STRONG LOW LEVEL WARM AIR
ADVECTION WILL CONTINUE INTO FRIDAY WHICH SHOULD BE OUR WARMEST DAY
OF THE FORECAST WITH HIGHS IN THE MID TO UPPER 80S. MOISTURE WILL
REMAIN IN PLACE AS WELL WITH SFC DEWPOINTS FORECAST AROUND 70.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 AM CDT WED SEP 17 2014
UPPER RIDGE WILL FLATTEN AND MOVE OVERHEAD WHILE A SHORTWAVE
TROUGH OVER THE NORTHERN PLAINS WILL ALLOW A WEAK COLD FRONT TO
DROP SOUTH INTO THE NORTHERN CWA AROUND 06Z/SAT. EARLIER THIS WEEK
WE WERE A BIT CONCERNED WITH THE AMOUNT OF MOISTURE TS ODILE WAS
GOING TO BRING TO THE FORECAST AREA BUT LATEST MODEL RUNS
CONTINUE TO SHOW THIS WILL MOVE JUST TO OUR SOUTH ACROSS KANSAS.
THE 00Z ECMWF WASHES THE COLD FRONT OUT OVER THE AREA WITH A LACK
OF UPPER LEVEL SUPPORT. THE 00Z GFS HOLDS ON TO A MORE DEFINED
COLD FRONT AND DROPS IT THROUGH THE CWA BY SATURDAY EVENING. IN
ANY CASE...THE FRONTAL BOUNDARY SEEMS TO BE SLOWED DOWN SOMEWHAT
FROM PREVIOUS RUNS SO THERE IS A BIT OF CONCERN FOR LINGERING
PCPN IN OUR SOUTHERN CWA SATURDAY EVENING.
THE REMAINDER OF THE FORECAST LOOKS DRY WITH SLIGHTLY BELOW NORMAL
TEMPERATURES INTO EARLY NEXT WEEK AS A DEEPENING TROUGH TO OUR
NORTHEAST DRAGS COOLER TEMPS INTO THE AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1134 PM CDT TUE SEP 16 2014
BKN-OVC CLOUD LAYER AROUND FL045 CONTINUES TO SLOWLY WORK
SOUTHEAST ACROSS EASTERN NEBRASKA AT THE START OF THE PERIOD.
BIG QUESTION IS WHETHER SKIES CLEAR OR SOME CLOUDS LINGER THROUGH
THE MORNING. RAP MAINTAINS 850MB RH OVER FAR EASTERN NEBRASKA
THROUGH SUNRISE SO IF THIS IS THE CASE FOG WILL BE LESS LIKELY.
OTHERWISE VFR CONDITIONS EXPECTED AFTER 15Z AT ALL SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1142 PM CDT TUE SEP 16 2014
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 300 PM CDT TUE SEP 16 2014
ALTHOUGH FORECAST CONCERNS ARE RELATIVELY MINOR IN THE SHORT
TERM...THERE ARE SEVERAL MOVING PARTS THAT COULD CREATE A
CHANGEABLE FORECAST.
FORECAST AREA WILL REMAIN IN NWRLY UPPER FLOW THROUGH LATE
THURSDAY BEFORE SHORTWAVE ENERGY FLATTENS UPPER RIDGE EWD ACROSS
THE FA. ANY UPPER WAVES IMPACTING THE AREA ARE WEAK AND ILL-
DEFINED...WITH LOW LEVEL THETA E ADVECTION PROBABLY PROVIDING MUCH
OF ANY LIFT ACROSS THE AREA. SOME OF THIS WARM ADVECTION ARRIVES
ACROSS MOSTLY SERN ZONES LATE TONIGHT AND THUS A SMALL TSTM
CHANCE WAS MAINTAINED GENERALLY S THRU SE OF LINCOLN. ALSO AN AREA
OF LOW CLOUDS...ROUGHLY MARKING THE EDGE OF THE H85 MOISTURE
RETURN...WILL BE SPREADING ACROSS THE FA EARLY AND MAY LIMIT FOG
REDEVELOPMENT. HOWEVER...WILL MENTION PATCHY FOG MAINLY SRN AREAS
OUTSIDE OF WHERE THUNDERSTORM CHANCES WILL BE CARRIED AS LOW/MID
50 DEWPTS SPREAD NE. CLOUDS SHOULD BRING MILDER LOWS TO THE FA
WITH LITTLE CHANGES. THE LOWER CLOUDS APPEAR TO MIX OUT ON
WEDNESDAY AND 12Z GFS/NAM/ECMWF POINT TO MAX TEMPS PERHAPS A
CATEGORY WARMER THAN EARLIER FORECAST AND THESE WERE RAISED TO
NEAR MET GUIDANCE. HEATING AND INCREASED MOISTURE/INSTABILITY
COULD ALLOW FOR LATE AFTN CONVECTION TO DEVELOP SWRN ZONES...WITH
SREF INCREASING RISK LAST FEW RUNS...AND A SMALL CHANCE WAS
INSERTED LATE WITH POPS CARRIED INTO WED NIGHT FAR S. WITH NW FLOW
ALOFT...A SMALL CONDITIONAL SEVERE THREAT DOES EXIST AS SHEAR IS A
LITTLE SUPPORTIVE.
AS H85/SFC DWPTS CONTINUING RISING INTO WED NIGHT LOW CLOUDS
AGAIN LOOK LIKELY BY THURSDAY MORNING. ALTHOUGH FOG AND DRIZZLE
ALSO POSSIBLE...WILL WAIT FOR ANOTHER MODEL RUN OR TWO TO ASSESS
DEPTH AND OTHER FACTORS. WITH INCREASING SERLY WINDS THU AFTN SOME
BREAKS EXPECTED...BUT POSSIBLY NOT QUICKLY ENOUGH TO ALLOW MAX
TEMPS TO GET AS WARM AS THOSE FORECAST FOR WED.
AS UPPER FLOW FLATTENS OVER THE FA TOWARD FRIDAY...LEFT IN SMALL
POPS NERN ZONES THU NGT AS LOW LEVEL JET STRENGTHENS AHEAD OF THIS
ALLOWING MORE UNSTABLE AIR TO SPREAD NE AS WELL. FRIDAY LOOKS LIKE
THE WARMEST DAY OF AT LEAST THE NEXT 7...WITH GOOD MIXING ON
MODERATELY STRONG SW WINDS. BOOSTED BOTH WINDS AND TEMPS A BIT.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE SEP 16 2014
LOOKS LIKE 12Z ECMWF TAKES REMNANTS OF TS ODILE THRU KS...
FOLLOWING LEAD OF FARTHER S GFS WHICH CONTINUED TO DO SO WITH 12Z
RUN. HOWEVER...SOME SUBTROPICAL MOISTURE ON ITS NORTH END COULD
STILL BE OVER THE FA AND WITH NRN STREAM WAVE DRIVING A COLD
FRONT ACROSS...HIGH CHANCE/LIKELY POPS WERE MAINTAINED SERN ZONES
ON SATURDAY. LINGERED SMALL POPS FAR SE SAT NIGHT...BUT COULD
VERY WELL SEE THE ACTIVITY SE OF THE FA BY THEN. REST OF THE
FORECAST WAS DRY.
WITH BULK OF MOISTURE FM ODILE POSSIBLY REMAINING TO OUR
SOUTH...AMOUNT OF PREFRONTAL CONVECTION AND/OR CLOUDS MAY BE
LACKING ENOUGH TO ALLOW MAX TEMPS ON SATURDAY TO APPROACH THOSE
OF FRIDAY...SPECLY CNTRL/SRN ZONES. BUT FOR NOW LEFT MODEL BLEND
ALONE WITH MOSTLY 70S FOR HIGHS. PLEASANT TEMPERATURES LOOK TO
PREVAIL SUNDAY-TUESDAY WITH GFS/ECMWF BLEND SUGGESTING LOWER-MID
70S FOR MAX TEMPS. ALTHOUGH COULD SEE THE NEED TO LOWER MAX/MINS
SOME IF TROUGH DEEPENING TO OUR EAST DOES SO A BIT FARTHER SW.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1134 PM CDT TUE SEP 16 2014
BKN-OVC CLOUD LAYER AROUND FL045 CONTINUES TO SLOWLY WORK
SOUTHEAST ACROSS EASTERN NEBRASKA AT THE START OF THE PERIOD.
BIG QUESTION IS WHETHER SKIES CLEAR OR SOME CLOUDS LINGER THROUGH
THE MORNING. RAP MAINTAINS 850MB RH OVER FAR EASTERN NEBRASKA
THROUGH SUNRISE SO IF THIS IS THE CASE FOG WILL BE LESS LIKELY.
OTHERWISE VFR CONDITIONS EXPECTED AFTER 15Z AT ALL SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS ELKO NV
806 PM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC LOW IS ON DECK AND WILL BRING GUSTY AND
UNSTABLE CONDITIONS TO THE SILVER STATE. THIS SYSTEM HAS PROVEN TO
HAVE SUFFICIENT MOISTURE THAT WILL CONTINUE TO TRIGGER
THUNDERSTORM ACTIVITY TODAY. ISOLATED SHOWERS AND THUNDERSTORMS
WILL LINGER OVER NIGHT AND INTO THE MORNING. ADDITIONALLY...SMOKE
FROM THE CALIFORNIA FIRES WILL IMPACT PORTIONS OF NORTHERN NEVADA
FOR A COUPLE OF DAYS.
&&
.UPDATE...ADDED ISOLATED POPS IN FOR HUMBOLDT COUNTY THIS EVENING
AND OVERNIGHT BASED ON CURRENT TRENDS AND LATEST 3KM HRRR RUN.
ALSO ADDED SMOKE FOR THE OVERNIGHT PERIOD DUE TO ONGOING FIRES IN
CALIFORNIA. OTHER GRIDS WERE CHANGED AS REQUIRED. TEXT PRODUCTS
WILL BE SENT SOON.
&&
.PREV DISCUSSION... /ISSUED AT 207 PM /
SHORT TERM...TODAY THROUGH SATURDAY. MULTIPLE THUNDERSTORMS HAVE
ALREADY DEVELOPED OVER NE NV TODAY...MAINLY ELKO COUNTY. THE PW
FROM THE LATEST ELKO SOUNDING WAS .84 OF AN INCH WHICH IS 188
PERCENT OF NORMAL....AND THE PROGGED SOUNDING FOR BOTH ELY AND
ELKO HOLD ONTO THE MOISTURE OVER NIGHT. FOR THE REMAINDER OF THE
DAY...THE NAM 12 PUMMELS THE EASTERN ZONES WITH -3 TO -4
LIS...WIDESPREAD +1000 J/KG OF CAPE AND SPIKED BULK RICHARDSON
NUMBERS...WHICH GETS SUPPORT FROM THE HRRR. THE GFS AND THE EC
BOTH HAVE THE H5 LOW PLUNGING OVER THE COAST OF CA...WHICH WILL
RESULT IN A TEMPORARY REPRIEVE IN TS ACTIVITY BEFORE THE LOW
RECURVES AND TRACKS INLAND RESULTING IN ANOTHER ROUND OF
CONVECTION LATE IN THE FORECAST PERIOD...PUSHING FROM
SOUTHERN/CENTRAL NV INTO NORTHERN NV.
LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY. CUTOFF LOW MOVING
INTO WESTERN NEVADA SATURDAY NIGHT WEAKENS INTO SUNDAY AS IT PUSHES
EAST-NORTHEAST INTO UTAH AND IDAHO BY SUNDAY NIGHT. MODELS IN PRETTY
GOOD AGREEMENT THROUGH THE WEEKEND HANDLING THE LOW/OPEN WAVE. MINOR
DISCREPANCIES WITH TIMING AND TRACK DO HOWEVER RESULT IN DIFFERENCES
ON WHERE PRECIPITATION SETS UP. ECMWF AND GFS ARE BOTH A LITTLE
QUICKER TO BRING THE MOISTURE UP INTO CENTRAL NEVADA SATURDAY
NIGHT...AND INTO NORTHERN NEVADA BY EARLY SUNDAY MORNING. NAM MODEL
BEING SLOWER BY 6-8HRS ON THE NORTHERN MOISTURE PUSH. MODELS ALL
AGREE THAT THE LOW/OPEN WAVE WILL HAVE QUITE A BIT OF ASSOCIATED
MOISTURE/QPF...WITH A QUARTER TO HALF AN INCH OF RAIN POSSIBLE OVER
THE CENTRAL NEVADA HIGHLAND AREAS AND NORTH INTO THE RUBY MOUNTAINS.
SHOWERS DIMINISH BY SUNDAY EVENING IN ALL AREAS EXCEPT NORTHEASTERN
ELKO COUNTY WHERE LIGHT SHOWERS ARE POSSIBLE OVERNIGHT AND THROUGH
MONDAY AFTERNOON. REGION WILL BE BETWEEN STORMS MONDAY NIGHT THROUGH
WEDNESDAY...HOWEVER EXPECT WINDS TO INCREASE TUESDAY INTO MID-WEEK
AHEAD OF AN APPROACHING TROUGH. WESTERN HUMBOLDT COUNTY MAY SEE SOME
SHOWERS RETURNING BY THURSDAY AFTERNOON...THOUGH THE REMAINDER OF
NORTHERN AND CENTRAL NEVADA SHOULD REMAIN DRY MONDAY NIGHT THROUGH
THURSDAY. TEMPERATURES TO REMAIN ABOVE NORMAL THIS WEEKEND DUE TO
THE CLOUD COVER...AND NEXT WEEK AS WARMER AIR SPREADS UP UNDER THE
SOUTHWESTERLY FLOW ALOFT.
AVIATION...SMOKE FROM CENTRAL CALIFORNIA WILDFIRES WILL RESULT IN
PERIODS OF REDUCED VISIBILITY AT KWMC THROUGH AT LEAST THIS
AFTERNOON AND LIKELY INTO TONIGHT. STRONG THUNDERSTORMS WILL IMPACT
THE KEKO TERMINAL FROM EARLY TO MID-AFTERNOON TODAY...WHILE STORMS
AT KELY WILL BE A LITTLE LATER IN DEVELOPING...GENERALLY EXPECTED
FROM MID-AFTERNOON THROUGH THE MID-EVENING HOURS. KTPH SHOULD BE
STORM-FREE TODAY WITH SOME CU TO THE NORTH AND EAST.
FIRE WEATHER...NUMEROUS LIGHTNING STRIKES OBSERVED EARLIER TODAY OVER
468...469 AND 470 TODAY. ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO IMPACT PORTIONS OF EASTERN AND
NORTHERN NEVADA TONIGHT.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
86/93
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1145 AM MDT WED SEP 17 2014
.AVIATION...
18Z TAF CYCLE
DEEP ATMOSPHERIC MOISTURE TO REMAIN OVER NORTHERN AND CENTRAL NEW
MEXICO FOR THE NEXT 24 HOURS AS ODILE/S REMAINS TRACK INTO THE REGION.
BANDS OF -RA TO CONTINUE TO MOVE OVER THE REGION WITH ISOLD TO SCT
TSTMS DEVELOPING WHERE CLOUDS TEMPORARILY BREAK. MTS WILL BE
FREQUENTLY OBSCURED IN MVFR TO IFR CIGS/VSBYS ESPECIALLY ALONG
AND SOUTH OF INTERSTATE 40 THROUGH 18/12Z.
&&
.PREV DISCUSSION...406 AM MDT WED SEP 17 2014...
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ODILE WILL CONTINUE TO IMPACT THE
AREA THE REMAINDER OF THE WORK WEEK. RAIN AND EMBEDDED THUNDERSTORMS
WILL BE MOST WIDESPREAD ACROSS CENTRAL AND SOUTHERN AREAS THROUGH
TONIGHT...EXPANDING NORTHEASTWARD AND INTENSIFYING THURSDAY INTO
THURSDAY NIGHT AS THE CORE OF THE REMNANT LOW PASSES OVER THE
HEART OF THE STATE. THE THREAT OF AREAL FLOODING AND POTENTIALLY
LIFE-THREATENING FLASH FLOODING WILL BE GREATEST IN THE SOUTHWESTERN
AND SOUTH CENTRAL MOUNTAINS AND ADJACENT HIGHLANDS BUT LOCALIZED
FLASH FLOODING WILL BE A THREAT AREAWIDE. A SLOW AND GRADUAL
DRYING AND CLEARING TREND IS EXPECTED IN WESTERN NEW MEXICO ON
FRIDAY...BUT EASTERN SECTIONS OF THE STATE COULD CONTINUE TO SEE
SHOWERS AND THUNDERSTORMS WITH A LOCALLY HEAVY RAINFALL THREAT.
FOLLOWING A BRIEF BREAK IN THE SHOWER PATTERN SATURDAY...AN ACTIVE
PATTERN RETURNS EARLY NEXT WEEK.
&&
.DISCUSSION...
ONLY CHANGES TO PREVIOUS FLASH FLOOD WATCH WAS TO EXTEND IT THROUGH
THURSDAY...AND TO ADD THE REMAINDER OF CHAVES COUNTY. FURTHER TIME
AND AREAL EXTENSIONS CAN BE EXPECTED BY LATER SHIFTS TO COVER THURSDAY
NIGHT INTO FRIDAY AS THE EVENT CONTINUES TO UNFOLD.
PER NHC 3AM MDT UPDATE...THE CENTER OF ODILE WAS ABOUT 85 MILES
SOUTH OF PUERTO PENASCO MX AND SLOWLY MOVING NNE AT 6 MPH. A TURN
TOWARD THE NE IS EXPECTED TODAY AS THE TROPICAL CYCLONE RAPIDLY
WEAKENS OVER LAND. THAT PROCESS MAY BE UNDER WAY ALREADY THIS
MORNING WITH EVIDENCE IN WATER VAPOR/INFRARED SATELLITE IMAGERY
THAT THE MID/UPPER CIRCULATION IS BEGINNING TO GET INCREASINGLY SHEARED
NEWD.
THE OFFICIAL TRACK BRINGS THE REMNANT CIRCULATION CLOSE TO TUCSON
LATE THIS EVENING AND THEN INTO OUR SW ZONES SOMETIME THURSDAY
MORNING. THE GFS AND ECMWF ARE PRETTY CLOSE SHOWING THE REMNANT
CIRCULATION OVER CATRON COUNTY NEAR THE NM/AZ LINE BY MIDDAY
THURSDAY. THEREAFTER...SIGNIFICANT TRENDING DIFFERENCES CONTINUE WITH
THE ECMWF KEEPING A BROAD BUT WELL- DEFINED LOW CENTER BETWEEN
FARMINGTON AND ALBUQUERQUE WHILE THE GFS...WHICH APPEARS TO
SUFFER FROM CONVECTIVE FEEDBACK ISSUES IN LATER PERIODS...GENERALLY
DRIVES THE REMNANT CIRCULATION MORE EASTERLY THAN NELY. TRACKING
THE CORE OF THIS REMNANT CIRCULATION WILL BE CRITICAL AS IT WILL
GENERATE TREMENDOUS RAINFALL RATES AS IT CONTRACTS AND INTERACTS
WITH THE COMPLEX TERRAIN OF WC/SW NEW MEXICO. POTENTIAL FOR LIFE-
THREATENING FLOODING/FLASH FLOODING WILL BE GREATEST FOR THE GILA AS WELL
AS BURN SCARS ACROSS LINCOLN COUNTY...BUT THE POTENTIAL FOR
SERIOUS FLASH FLOODING WILL EXIST THROUGH OUT THE CURRENT WATCH
AREA PARTICULARLY LOWLAND AREAS OF SOCORRO/CATRON COUNTIES THAT
HAVE ALREADY RECEIVED SIGNIFICANT RAINFALL.
MEANWHILE...POP PLACEMENT FOR WEST-CENTRAL...MIDDLE RIO GRANDE VALLEY AND
NEIGHBORING CENTRAL HIGHLAND ZONES CONTINUES TO BE CHALLENGING AS
PRECIP BANDS MIGRATING NORTHWARD SEEM TO BE STRUGGLING BENEATH A
BROADLY CONFLUENT FLOW ALOFT. THE LATEST HRRR IS QUITE BULLISH ON
PROSPECT FOR THE ABOVE MENTIONED AREAS AND ESPECIALLY TOWARD
GRANTS/GALLUP AND TRENDED POP UPWARD CLOSER TO MAV GUIDANCE.
OTHERWISE...NOT CONVINCED WE WILL SEE WIDESPREAD/NUMEROUS
THUNDERSTORM ACTIVITY OVER SC/SW ZONES TODAY GIVEN THE LACK OF
STRONG SURFACE HEATING/INSTABILITY BUT THE WRF/HRRR DO SUGGEST A
SIGNIFICANT INCREASE IN CONVECTIVE PRECIP FOR THE SE PLAINS LATER
TODAY/EVENING.
LINGERING TROPICAL MOISTURE AND MORE SUNSHINE MAY SPELL A MORE
ACTIVE DAY ON FRIDAY ACROSS THE CENTRAL/WEST THAN CURRENTLY
ADVERTISED BUT TRENDING LESS ACTIVE BY SATURDAY BEFORE NEXT UPTICK
IN SHOWER/STORM COVERAGE SUNDAY/MONDAY. SEE BELOW FOR A MORE DETAILED
EXTENDED ANALYSIS. KJ
&&
.FIRE WEATHER...
MODELS CONTINUE TO HAVE GOOD AGREEMENT ON THE REMNANTS OF NOW
TROPICAL STORM ODILE TRACKING NORTHEASTWARD FROM THE UPPER GULF OF
CALIFORNIA ACROSS THE FIRE WEATHER FORECAST AREA TODAY THROUGH
FRIDAY. ONCE THE SYSTEM BECOMES EXTRATROPICAL...THE CENTER OF UPPER
LEVEL LOW PRESSURE IS PROGGED TO TRACK NORTHEASTWARD OVER TUCSON
TONIGHT...GALLUP THURSDAY...THEN CHAMA/TAOS ON FRIDAY. THIS WILL
PLACE SOUTHWEST/WEST CENTRAL...CENTRAL...THEN NORTHEAST PARTS OF THE
FORECAST AREA UNDER ROBUST DYNAMICS FOR LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE FOREBODING PRECIPITATION FORECAST FROM THE
WEATHER PREDICTION CENTER CALLS FOR AN ADDITIONAL 2 TO 6 INCHES OF
RAIN FROM THE GALLINAS MOUNTAINS WESTWARD ACROSS SOCORRO COUNTY AND
THE WEST CENTRAL HIGHLANDS. AMOUNTS TREND GRADUALLY DOWNWARD NORTH
AND NORTHEASTWARD WITH 1 INCH ACCUMULATIONS POSSIBLE AS FAR NORTH AS THE
SOUTHERN CHUSKAS...THE BRAZOS AND CLAYTON. EXCEPT FOR THE FOUR
CORNERS REGION...THE WHOLE FORECAST AREA HAS A GOOD SHOT OF WETTING
PRECIPITATION THIS WEEK. IT MAY TAKE TIL THURSDAY NIGHT AND FRIDAY
FOR SIGNIFICANT PRECIP TO REACH THE NORTHERN BORDER.
IN THE WAKE OF ODILES REMNANTS MODELS AGREE BETTER ON AN UPPER LEVEL
LOW PRESSURE SYSTEM STALLING OFF THE CA COAST FRIDAY NIGHT AND
SATURDAY. THEY THEN DIVERGE IN TRACK AND TIMING WITH THE STORM EJECTING
NORTHEASTWARD EITHER ACROSS THE CENTRAL OR NORTHERN ROCKIES LATE IN
THE WEEKEND AND EARLY IN THE COMING WEEK. HOWEVER...MODELS DO
GENERALLY AGREE ON THE SYSTEM DRAWING A BACK DOOR COLD FRONT INTO
THE FORECAST AREA FROM THE NE FRIDAY NIGHT AND INTO AZ SATURDAY
NIGHT. THIS MAY RESULT IN A FAIRLY STRONG EAST CANYON WIND IN THE
RIO GRANDE VALLEY SATURDAY NIGHT. HUMIDITIES SHOULD TREND DOWNWARD
BY 10 TO 20 PERCENT ON SATURDAY...ONLY TO REBOUND A FEW TO 16
PERCENT ON SUNDAY BEHIND THE COLD FRONT. WITH THE DECREASE IN
MOISTURE THERE WILL BE A SIGNIFICANT DOWNTICK IN THUNDERSTORM
COVERAGE ON SATURDAY. THEN...THE CHANCE FOR THUNDERSTORMS WILL TREND
UPWARD AGAIN SUNDAY INTO THE COMING WORK WEEK AS THE UPPER LOW
PASSING NORTH OF NM DRAWS A ROBUST MONSOON MOISTURE PLUME NORTHWARD
OVER THE STATE. AT THIS TIME...CENTRAL AND WESTERN AREAS LOOK
FAVORED FOR WETTING THUNDERSTORM CHANCES SUNDAY AND MONDAY. THE
MOISTURE PLUME MAY THEN FAVOR CENTRAL AND EASTERN AREAS FOR WETTING
PRECIPITATION TUESDAY...DEPENDING ON THE TRACK OF THE UPPER LOW AND
HOW QUICKLY IT EXITS THE ROCKIES ONTO THE PLAINS.
WITH BANDS OF PRECIPITATION LIKELY TO TRACK NORTHWARD INTO THE
FORECAST AREA TODAY AND THURSDAY...HIGH TEMPERATURES SHOULD VARY A
FEW TO 11 DEGREES BELOW NORMAL. NEAR TO ABOVE NORMAL READINGS ARE
EXPECTED ALONG THE NORTHERN BORDER. LOW TEMPERATURES DURING THIS
PERIOD SHOULD REMAIN ABOVE NORMAL DUE TO GENERALLY SOUTHERLY FLOW
AND OVERNIGHT CLOUD COVER. TEMPERATURES SHOULD BEGIN TO REBOUND
TOWARD NORMAL ON FRIDAY...EXCEPT PERHAPS ACROSS THE EAST WHERE SOME
OF THE BETTER SUBTROPICAL MOISTURE MAY LINGER. HIGH TEMPS SHOULD
THEN REACH NEAR AND ABOVE NORMAL AREAWIDE ON SATURDAY...ONLY TO DROP
AGAIN ON SUNDAY IN THE WAKE OF THE COLD FRONT.
IN ADDITION...POCKETS OF POOR VENTILATION ARE FORECAST
TODAY...FRIDAY...MONDAY AND TUESDAY...WITH SOME IMPROVEMENT
THURSDAY...SATURDAY AND SUNDAY. MEAGER HAINES VALUES ARE ALSO
EXPECTED OVER THE NEXT 7 DAYS. 44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ508-509-520-524>526-538>540.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
610 AM MDT WED SEP 17 2014
.AVIATION...
12Z TAF CYCLE
AN ORGANIZED BAND OF PCPN SHOULD CONTINUE TO SHIFT SLOWLY N AND NEWD
FROM THE LOWER RIO GRANDE VALLEY ACROSS CENTRAL AND E PARTS OF THE
FORECAST AREA THOUGH MID DAY AND INTO THE EARLY AFTN. THIS WILL
BRING LIGHT TO MDT RAIN WITH RISK OF MVFR CEILINGS TO AIRPORTS
LIKE KABQ...KSAF...KLVS...KSRR...AND POSSIBLY KTCC. THE HIGH
RESOLUTION RAPID REFRESH MODEL SEEMS TO HAVE PICKED UP ON THIS
BAND...AND SUGGESTS SCT TO ISOLD THUNDERSTORMS MAY DEVELOP IN ITS
WAKE MAINLY EAST OF THE CENTRAL MT CHAIN. KROW LOOKS TO BE A BIT
TOO SE OF THIS BAND FOR MUCH PRECIP...BUT RUNS THE RISK OF IFR AND
LIFR CONDITIONS UNTIL LATE MORNING. THUNDERSTORMS COULD REACH KROW
TOO IN THE AFTN. OTHERWISE...WDSPR MT OBSCURATIONS ARE EXPECTED
TODAY. MODELS SUGGEST ANOTHER ORGANIZED BAND OF PRECIPITATION WITH
MVFR AND POSSIBLY IFR CONDITIONS WILL IMPACT AREAS S OF I-40
TONIGHT.
44
&&
.PREV DISCUSSION...406 AM MDT WED SEP 17 2014...
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ODILE WILL CONTINUE TO IMPACT THE
AREA THE REMAINDER OF THE WORK WEEK. RAIN AND EMBEDDED THUNDERSTORMS
WILL BE MOST WIDESPREAD ACROSS CENTRAL AND SOUTHERN AREAS THROUGH
TONIGHT...EXPANDING NORTHEASTWARD AND INTENSIFYING THURSDAY INTO
THURSDAY NIGHT AS THE CORE OF THE REMNANT LOW PASSES OVER THE
HEART OF THE STATE. THE THREAT OF AREAL FLOODING AND POTENTIALLY
LIFE-THREATENING FLASH FLOODING WILL BE GREATEST IN THE SOUTHWESTERN
AND SOUTH CENTRAL MOUNTAINS AND ADJACENT HIGHLANDS BUT LOCALIZED
FLASH FLOODING WILL BE A THREAT AREAWIDE. A SLOW AND GRADUAL
DRYING AND CLEARING TREND IS EXPECTED IN WESTERN NEW MEXICO ON
FRIDAY...BUT EASTERN SECTIONS OF THE STATE COULD CONTINUE TO SEE
SHOWERS AND THUNDERSTORMS WITH A LOCALLY HEAVY RAINFALL THREAT.
FOLLOWING A BRIEF BREAK IN THE SHOWER PATTERN SATURDAY...AN ACTIVE
PATTERN RETURNS EARLY NEXT WEEK.
&&
.DISCUSSION...
ONLY CHANGES TO PREVIOUS FLASH FLOOD WATCH WAS TO EXTEND IT THROUGH
THURSDAY...AND TO ADD THE REMAINDER OF CHAVES COUNTY. FURTHER TIME
AND AREAL EXTENSIONS CAN BE EXPECTED BY LATER SHIFTS TO COVER THURSDAY
NIGHT INTO FRIDAY AS THE EVENT CONTINUES TO UNFOLD.
PER NHC 3AM MDT UPDATE...THE CENTER OF ODILE WAS ABOUT 85 MILES
SOUTH OF PUERTO PENASCO MX AND SLOWLY MOVING NNE AT 6 MPH. A TURN
TOWARD THE NE IS EXPECTED TODAY AS THE TROPICAL CYCLONE RAPIDLY
WEAKENS OVER LAND. THAT PROCESS MAY BE UNDER WAY ALREADY THIS
MORNING WITH EVIDENCE IN WATER VAPOR/INFRARED SATELLITE IMAGERY
THAT THE MID/UPPER CIRCULATION IS BEGINNING TO GET INCREASINGLY SHEARED
NEWD.
THE OFFICIAL TRACK BRINGS THE REMNANT CIRCULATION CLOSE TO TUCSON
LATE THIS EVENING AND THEN INTO OUR SW ZONES SOMETIME THURSDAY
MORNING. THE GFS AND ECMWF ARE PRETTY CLOSE SHOWING THE REMNANT
CIRCULATION OVER CATRON COUNTY NEAR THE NM/AZ LINE BY MIDDAY
THURSDAY. THEREAFTER...SIGNIFICANT TRENDING DIFFERENCES CONTINUE WITH
THE ECMWF KEEPING A BROAD BUT WELL- DEFINED LOW CENTER BETWEEN
FARMINGTON AND ALBUQUERQUE WHILE THE GFS...WHICH APPEARS TO
SUFFER FROM CONVECTIVE FEEDBACK ISSUES IN LATER PERIODS...GENERALLY
DRIVES THE REMNANT CIRCULATION MORE EASTERLY THAN NELY. TRACKING
THE CORE OF THIS REMNANT CIRCULATION WILL BE CRITICAL AS IT WILL
GENERATE TREMENDOUS RAINFALL RATES AS IT CONTRACTS AND INTERACTS
WITH THE COMPLEX TERRAIN OF WC/SW NEW MEXICO. POTENTIAL FOR LIFE-
THREATENING FLOODING/FLASH FLOODING WILL BE GREATEST FOR THE GILA AS WELL
AS BURN SCARS ACROSS LINCOLN COUNTY...BUT THE POTENTIAL FOR
SERIOUS FLASH FLOODING WILL EXIST THROUGH OUT THE CURRENT WATCH
AREA PARTICULARLY LOWLAND AREAS OF SOCORRO/CATRON COUNTIES THAT
HAVE ALREADY RECEIVED SIGNIFICANT RAINFALL.
MEANWHILE...POP PLACEMENT FOR WEST-CENTRAL...MIDDLE RIO GRANDE VALLEY AND
NEIGHBORING CENTRAL HIGHLAND ZONES CONTINUES TO BE CHALLENGING AS
PRECIP BANDS MIGRATING NORTHWARD SEEM TO BE STRUGGLING BENEATH A
BROADLY CONFLUENT FLOW ALOFT. THE LATEST HRRR IS QUITE BULLISH ON
PROSPECT FOR THE ABOVE MENTIONED AREAS AND ESPECIALLY TOWARD
GRANTS/GALLUP AND TRENDED POP UPWARD CLOSER TO MAV GUIDANCE.
OTHERWISE...NOT CONVINCED WE WILL SEE WIDESPREAD/NUMEROUS
THUNDERSTORM ACTIVITY OVER SC/SW ZONES TODAY GIVEN THE LACK OF
STRONG SURFACE HEATING/INSTABILITY BUT THE WRF/HRRR DO SUGGEST A
SIGNIFICANT INCREASE IN CONVECTIVE PRECIP FOR THE SE PLAINS LATER
TODAY/EVENING.
LINGERING TROPICAL MOISTURE AND MORE SUNSHINE MAY SPELL A MORE
ACTIVE DAY ON FRIDAY ACROSS THE CENTRAL/WEST THAN CURRENTLY
ADVERTISED BUT TRENDING LESS ACTIVE BY SATURDAY BEFORE NEXT UPTICK
IN SHOWER/STORM COVERAGE SUNDAY/MONDAY. SEE BELOW FOR A MORE DETAILED
EXTENDED ANALYSIS. KJ
&&
.FIRE WEATHER...
MODELS CONTINUE TO HAVE GOOD AGREEMENT ON THE REMNANTS OF NOW
TROPICAL STORM ODILE TRACKING NORTHEASTWARD FROM THE UPPER GULF OF
CALIFORNIA ACROSS THE FIRE WEATHER FORECAST AREA TODAY THROUGH
FRIDAY. ONCE THE SYSTEM BECOMES EXTRATROPICAL...THE CENTER OF UPPER
LEVEL LOW PRESSURE IS PROGGED TO TRACK NORTHEASTWARD OVER TUCSON
TONIGHT...GALLUP THURSDAY...THEN CHAMA/TAOS ON FRIDAY. THIS WILL
PLACE SOUTHWEST/WEST CENTRAL...CENTRAL...THEN NORTHEAST PARTS OF THE
FORECAST AREA UNDER ROBUST DYNAMICS FOR LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE FOREBODING PRECIPITATION FORECAST FROM THE
WEATHER PREDICTION CENTER CALLS FOR AN ADDITIONAL 2 TO 6 INCHES OF
RAIN FROM THE GALLINAS MOUNTAINS WESTWARD ACROSS SOCORRO COUNTY AND
THE WEST CENTRAL HIGHLANDS. AMOUNTS TREND GRADUALLY DOWNWARD NORTH
AND NORTHEASTWARD WITH 1 INCH ACCUMULATIONS POSSIBLE AS FAR NORTH AS THE
SOUTHERN CHUSKAS...THE BRAZOS AND CLAYTON. EXCEPT FOR THE FOUR
CORNERS REGION...THE WHOLE FORECAST AREA HAS A GOOD SHOT OF WETTING
PRECIPITATION THIS WEEK. IT MAY TAKE TIL THURSDAY NIGHT AND FRIDAY
FOR SIGNIFICANT PRECIP TO REACH THE NORTHERN BORDER.
IN THE WAKE OF ODILES REMNANTS MODELS AGREE BETTER ON AN UPPER LEVEL
LOW PRESSURE SYSTEM STALLING OFF THE CA COAST FRIDAY NIGHT AND
SATURDAY. THEY THEN DIVERGE IN TRACK AND TIMING WITH THE STORM EJECTING
NORTHEASTWARD EITHER ACROSS THE CENTRAL OR NORTHERN ROCKIES LATE IN
THE WEEKEND AND EARLY IN THE COMING WEEK. HOWEVER...MODELS DO
GENERALLY AGREE ON THE SYSTEM DRAWING A BACK DOOR COLD FRONT INTO
THE FORECAST AREA FROM THE NE FRIDAY NIGHT AND INTO AZ SATURDAY
NIGHT. THIS MAY RESULT IN A FAIRLY STRONG EAST CANYON WIND IN THE
RIO GRANDE VALLEY SATURDAY NIGHT. HUMIDITIES SHOULD TREND DOWNWARD
BY 10 TO 20 PERCENT ON SATURDAY...ONLY TO REBOUND A FEW TO 16
PERCENT ON SUNDAY BEHIND THE COLD FRONT. WITH THE DECREASE IN
MOISTURE THERE WILL BE A SIGNIFICANT DOWNTICK IN THUNDERSTORM
COVERAGE ON SATURDAY. THEN...THE CHANCE FOR THUNDERSTORMS WILL TREND
UPWARD AGAIN SUNDAY INTO THE COMING WORK WEEK AS THE UPPER LOW
PASSING NORTH OF NM DRAWS A ROBUST MONSOON MOISTURE PLUME NORTHWARD
OVER THE STATE. AT THIS TIME...CENTRAL AND WESTERN AREAS LOOK
FAVORED FOR WETTING THUNDERSTORM CHANCES SUNDAY AND MONDAY. THE
MOISTURE PLUME MAY THEN FAVOR CENTRAL AND EASTERN AREAS FOR WETTING
PRECIPITATION TUESDAY...DEPENDING ON THE TRACK OF THE UPPER LOW AND
HOW QUICKLY IT EXITS THE ROCKIES ONTO THE PLAINS.
WITH BANDS OF PRECIPITATION LIKELY TO TRACK NORTHWARD INTO THE
FORECAST AREA TODAY AND THURSDAY...HIGH TEMPERATURES SHOULD VARY A
FEW TO 11 DEGREES BELOW NORMAL. NEAR TO ABOVE NORMAL READINGS ARE
EXPECTED ALONG THE NORTHERN BORDER. LOW TEMPERATURES DURING THIS
PERIOD SHOULD REMAIN ABOVE NORMAL DUE TO GENERALLY SOUTHERLY FLOW
AND OVERNIGHT CLOUD COVER. TEMPERATURES SHOULD BEGIN TO REBOUND
TOWARD NORMAL ON FRIDAY...EXCEPT PERHAPS ACROSS THE EAST WHERE SOME
OF THE BETTER SUBTROPICAL MOISTURE MAY LINGER. HIGH TEMPS SHOULD
THEN REACH NEAR AND ABOVE NORMAL AREAWIDE ON SATURDAY...ONLY TO DROP
AGAIN ON SUNDAY IN THE WAKE OF THE COLD FRONT.
IN ADDITION...POCKETS OF POOR VENTILATION ARE FORECAST
TODAY...FRIDAY...MONDAY AND TUESDAY...WITH SOME IMPROVEMENT
THURSDAY...SATURDAY AND SUNDAY. MEAGER HAINES VALUES ARE ALSO
EXPECTED OVER THE NEXT 7 DAYS. 44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ508-509-520-524>526-539-540.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ538.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
406 AM MDT WED SEP 17 2014
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ODILE WILL CONTINUE TO IMPACT THE
AREA THE REMAINDER OF THE WORK WEEK. RAIN AND EMBEDDED THUNDERSTORMS
WILL BE MOST WIDESPREAD ACROSS CENTRAL AND SOUTHERN AREAS THROUGH
TONIGHT...EXPANDING NORTHEASTWARD AND INTENSIFYING THURSDAY INTO
THURSDAY NIGHT AS THE CORE OF THE REMNANT LOW PASSES OVER THE
HEART OF THE STATE. THE THREAT OF AREAL FLOODING AND POTENTIALLY
LIFE-THREATENING FLASH FLOODING WILL BE GREATEST IN THE SOUTHWESTERN
AND SOUTH CENTRAL MOUNTAINS AND ADJACENT HIGHLANDS BUT LOCALIZED
FLASH FLOODING WILL BE A THREAT AREAWIDE. A SLOW AND GRADUAL
DRYING AND CLEARING TREND IS EXPECTED IN WESTERN NEW MEXICO ON
FRIDAY...BUT EASTERN SECTIONS OF THE STATE COULD CONTINUE TO SEE
SHOWERS AND THUNDERSTORMS WITH A LOCALLY HEAVY RAINFALL THREAT.
FOLLOWING A BRIEF BREAK IN THE SHOWER PATTERN SATURDAY...AN ACTIVE
PATTERN RETURNS EARLY NEXT WEEK.
&&
.DISCUSSION...
ONLY CHANGES TO PREVIOUS FLASH FLOOD WATCH WAS TO EXTEND IT THROUGH
THURSDAY...AND TO ADD THE REMAINDER OF CHAVES COUNTY. FURTHER TIME
AND AREAL EXTENSIONS CAN BE EXPECTED BY LATER SHIFTS TO COVER THURSDAY
NIGHT INTO FRIDAY AS THE EVENT CONTINUES TO UNFOLD.
PER NHC 3AM MDT UPDATE...THE CENTER OF ODILE WAS ABOUT 85 MILES
SOUTH OF PUERTO PENASCO MX AND SLOWLY MOVING NNE AT 6 MPH. A TURN
TOWARD THE NE IS EXPECTED TODAY AS THE TROPICAL CYCLONE RAPIDLY
WEAKENS OVER LAND. THAT PROCESS MAY BE UNDER WAY ALREADY THIS
MORNING WITH EVIDENCE IN WATER VAPOR/INFRARED SATELLITE IMAGERY
THAT THE MID/UPPER CIRCULATION IS BEGINNING TO GET INCREASINGLY SHEARED
NEWD.
THE OFFICIAL TRACK BRINGS THE REMNANT CIRCULATION CLOSE TO TUCSON
LATE THIS EVENING AND THEN INTO OUR SW ZONES SOMETIME THURSDAY
MORNING. THE GFS AND ECMWF ARE PRETTY CLOSE SHOWING THE REMNANT
CIRCULATION OVER CATRON COUNTY NEAR THE NM/AZ LINE BY MIDDAY
THURSDAY. THEREAFTER...SIGNIFICANT TRENDING DIFFERENCES CONTINUE WITH
THE ECMWF KEEPING A BROAD BUT WELL- DEFINED LOW CENTER BETWEEN
FARMINGTON AND ALBUQUERQUE WHILE THE GFS...WHICH APPEARS TO
SUFFER FROM CONVECTIVE FEEDBACK ISSUES IN LATER PERIODS...GENERALLY
DRIVES THE REMNANT CIRCULATION MORE EASTERLY THAN NELY. TRACKING
THE CORE OF THIS REMNANT CIRCULATION WILL BE CRITICAL AS IT WILL
GENERATE TREMENDOUS RAINFALL RATES AS IT CONTRACTS AND INTERACTS
WITH THE COMPLEX TERRAIN OF WC/SW NEW MEXICO. POTENTIAL FOR LIFE-
THREATENING FLOODING/FLASH FLOODING WILL BE GREATEST FOR THE GILA AS WELL
AS BURN SCARS ACROSS LINCOLN COUNTY...BUT THE POTENTIAL FOR
SERIOUS FLASH FLOODING WILL EXIST THROUGH OUT THE CURRENT WATCH
AREA PARTICULARLY LOWLAND AREAS OF SOCORRO/CATRON COUNTIES THAT
HAVE ALREADY RECEIVED SIGNIFICANT RAINFALL.
MEANWHILE...POP PLACEMENT FOR WEST-CENTRAL...MIDDLE RIO GRANDE VALLEY AND
NEIGHBORING CENTRAL HIGHLAND ZONES CONTINUES TO BE CHALLENGING AS
PRECIP BANDS MIGRATING NORTHWARD SEEM TO BE STRUGGLING BENEATH A
BROADLY CONFLUENT FLOW ALOFT. THE LATEST HRRR IS QUITE BULLISH ON
PROSPECT FOR THE ABOVE MENTIONED AREAS AND ESPECIALLY TOWARD
GRANTS/GALLUP AND TRENDED POP UPWARD CLOSER TO MAV GUIDANCE.
OTHERWISE...NOT CONVINCED WE WILL SEE WIDESPREAD/NUMEROUS
THUNDERSTORM ACTIVITY OVER SC/SW ZONES TODAY GIVEN THE LACK OF
STRONG SURFACE HEATING/INSTABILITY BUT THE WRF/HRRR DO SUGGEST A
SIGNIFICANT INCREASE IN CONVECTIVE PRECIP FOR THE SE PLAINS LATER
TODAY/EVENING.
LINGERING TROPICAL MOISTURE AND MORE SUNSHINE MAY SPELL A MORE
ACTIVE DAY ON FRIDAY ACROSS THE CENTRAL/WEST THAN CURRENTLY
ADVERTISED BUT TRENDING LESS ACTIVE BY SATURDAY BEFORE NEXT UPTICK
IN SHOWER/STORM COVERAGE SUNDAY/MONDAY. SEE BELOW FOR A MORE DETAILED
EXTENDED ANALYSIS. KJ
&&
.FIRE WEATHER...
MODELS CONTINUE TO HAVE GOOD AGREEMENT ON THE REMNANTS OF NOW
TROPICAL STORM ODILE TRACKING NORTHEASTWARD FROM THE UPPER GULF OF
CALIFORNIA ACROSS THE FIRE WEATHER FORECAST AREA TODAY THROUGH
FRIDAY. ONCE THE SYSTEM BECOMES EXTRATROPICAL...THE CENTER OF UPPER
LEVEL LOW PRESSURE IS PROGGED TO TRACK NORTHEASTWARD OVER TUCSON
TONIGHT...GALLUP THURSDAY...THEN CHAMA/TAOS ON FRIDAY. THIS WILL
PLACE SOUTHWEST/WEST CENTRAL...CENTRAL...THEN NORTHEAST PARTS OF THE
FORECAST AREA UNDER ROBUST DYNAMICS FOR LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE FOREBODING PRECIPITATION FORECAST FROM THE
WEATHER PREDICTION CENTER CALLS FOR AN ADDITIONAL 2 TO 6 INCHES OF
RAIN FROM THE GALLINAS MOUNTAINS WESTWARD ACROSS SOCORRO COUNTY AND
THE WEST CENTRAL HIGHLANDS. AMOUNTS TREND GRADUALLY DOWNWARD NORTH
AND NORTHEASTWARD WITH 1 INCH ACCUMULATIONS POSSIBLE AS FAR NORTH AS THE
SOUTHERN CHUSKAS...THE BRAZOS AND CLAYTON. EXCEPT FOR THE FOUR
CORNERS REGION...THE WHOLE FORECAST AREA HAS A GOOD SHOT OF WETTING
PRECIPITATION THIS WEEK. IT MAY TAKE TIL THURSDAY NIGHT AND FRIDAY
FOR SIGNIFICANT PRECIP TO REACH THE NORTHERN BORDER.
IN THE WAKE OF ODILES REMNANTS MODELS AGREE BETTER ON AN UPPER LEVEL
LOW PRESSURE SYSTEM STALLING OFF THE CA COAST FRIDAY NIGHT AND
SATURDAY. THEY THEN DIVERGE IN TRACK AND TIMING WITH THE STORM EJECTING
NORTHEASTWARD EITHER ACROSS THE CENTRAL OR NORTHERN ROCKIES LATE IN
THE WEEKEND AND EARLY IN THE COMING WEEK. HOWEVER...MODELS DO
GENERALLY AGREE ON THE SYSTEM DRAWING A BACK DOOR COLD FRONT INTO
THE FORECAST AREA FROM THE NE FRIDAY NIGHT AND INTO AZ SATURDAY
NIGHT. THIS MAY RESULT IN A FAIRLY STRONG EAST CANYON WIND IN THE
RIO GRANDE VALLEY SATURDAY NIGHT. HUMIDITIES SHOULD TREND DOWNWARD
BY 10 TO 20 PERCENT ON SATURDAY...ONLY TO REBOUND A FEW TO 16
PERCENT ON SUNDAY BEHIND THE COLD FRONT. WITH THE DECREASE IN
MOISTURE THERE WILL BE A SIGNIFICANT DOWNTICK IN THUNDERSTORM
COVERAGE ON SATURDAY. THEN...THE CHANCE FOR THUNDERSTORMS WILL TREND
UPWARD AGAIN SUNDAY INTO THE COMING WORK WEEK AS THE UPPER LOW
PASSING NORTH OF NM DRAWS A ROBUST MONSOON MOISTURE PLUME NORTHWARD
OVER THE STATE. AT THIS TIME...CENTRAL AND WESTERN AREAS LOOK
FAVORED FOR WETTING THUNDERSTORM CHANCES SUNDAY AND MONDAY. THE
MOISTURE PLUME MAY THEN FAVOR CENTRAL AND EASTERN AREAS FOR WETTING
PRECIPITATION TUESDAY...DEPENDING ON THE TRACK OF THE UPPER LOW AND
HOW QUICKLY IT EXITS THE ROCKIES ONTO THE PLAINS.
WITH BANDS OF PRECIPITATION LIKELY TO TRACK NORTHWARD INTO THE
FORECAST AREA TODAY AND THURSDAY...HIGH TEMPERATURES SHOULD VARY A
FEW TO 11 DEGREES BELOW NORMAL. NEAR TO ABOVE NORMAL READINGS ARE
EXPECTED ALONG THE NORTHERN BORDER. LOW TEMPERATURES DURING THIS
PERIOD SHOULD REMAIN ABOVE NORMAL DUE TO GENERALLY SOUTHERLY FLOW
AND OVERNIGHT CLOUD COVER. TEMPERATURES SHOULD BEGIN TO REBOUND
TOWARD NORMAL ON FRIDAY...EXCEPT PERHAPS ACROSS THE EAST WHERE SOME
OF THE BETTER SUBTROPICAL MOISTURE MAY LINGER. HIGH TEMPS SHOULD
THEN REACH NEAR AND ABOVE NORMAL AREAWIDE ON SATURDAY...ONLY TO DROP
AGAIN ON SUNDAY IN THE WAKE OF THE COLD FRONT.
IN ADDITION...POCKETS OF POOR VENTILATION ARE FORECAST
TODAY...FRIDAY...MONDAY AND TUESDAY...WITH SOME IMPROVEMENT
THURSDAY...SATURDAY AND SUNDAY. MEAGER HAINES VALUES ARE ALSO
EXPECTED OVER THE NEXT 7 DAYS. 44
&&
.AVIATION...
06Z TAF CYCLE
TROPICAL STORM ODILE REMNANTS OVER THE NORTHERN GULF OF CALIFORNIA
WILL DRIFT INTO SOUTHEAST ARIZONA OVER THE NEXT 24 HOURS KEEPING
MOUNTAINS OBSCURED AND WIDESPREAD CLOUD COVER IN PLAY. HEAVIEST
RAINFALL WILL SET UP OVER SOUTHERN HALF OF NEW MEXICO...WITH ONLY
SPOTTY SHOWER COVERAGE TO THE NORTH. HAVE VCSH CARRIED IN TAFS TO
COVER EXPECTED PERIOD OF SHOWER COVERAGE...WITH SCT LAYERS
PLACE HOLDING FOR POSSIBLE EXCURSIONS INTO IFR/MVFR CIGS IN HEAVIER
SHOWERS. ROW CURRENTLY IN FOG WILL BATTLE LOW VIZ OVERNIGHT...WITH
VIZ IMPROVING FROM 17Z ONWARD WED MORNING.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 82 56 80 60 / 20 20 10 20
DULCE........................... 81 46 78 51 / 40 30 20 40
CUBA............................ 74 50 75 53 / 60 20 40 50
GALLUP.......................... 74 52 72 55 / 60 50 60 40
EL MORRO........................ 67 49 66 52 / 60 70 80 60
GRANTS.......................... 71 53 69 54 / 60 50 80 60
QUEMADO......................... 70 52 65 53 / 80 90 90 60
GLENWOOD........................ 72 57 68 58 / 80 100 100 60
CHAMA........................... 75 43 73 47 / 40 20 30 40
LOS ALAMOS...................... 75 52 72 54 / 40 20 40 60
PECOS........................... 73 52 68 54 / 40 30 50 60
CERRO/QUESTA.................... 76 45 73 49 / 30 20 20 30
RED RIVER....................... 67 43 65 45 / 30 10 20 40
ANGEL FIRE...................... 73 41 69 47 / 30 20 30 50
TAOS............................ 77 47 73 51 / 30 20 10 30
MORA............................ 73 49 69 52 / 30 20 40 60
ESPANOLA........................ 80 54 77 57 / 30 20 20 40
SANTA FE........................ 74 53 71 55 / 40 30 40 60
SANTA FE AIRPORT................ 77 54 73 56 / 40 30 50 60
ALBUQUERQUE FOOTHILLS........... 72 57 72 59 / 60 30 70 70
ALBUQUERQUE HEIGHTS............. 74 60 72 61 / 60 40 70 70
ALBUQUERQUE VALLEY.............. 76 58 74 60 / 60 40 70 70
ALBUQUERQUE WEST MESA........... 76 59 75 60 / 60 30 70 60
LOS LUNAS....................... 76 59 73 61 / 60 50 70 70
RIO RANCHO...................... 75 60 76 60 / 50 30 60 60
SOCORRO......................... 71 60 73 61 / 80 80 80 70
SANDIA PARK/CEDAR CREST......... 75 53 72 56 / 50 30 70 80
TIJERAS......................... 75 54 72 57 / 60 40 70 70
MORIARTY/ESTANCIA............... 74 52 69 55 / 60 40 70 70
CLINES CORNERS.................. 71 54 66 55 / 50 30 70 80
GRAN QUIVIRA.................... 69 55 66 57 / 80 60 90 70
CARRIZOZO....................... 69 59 69 59 / 80 70 80 70
RUIDOSO......................... 64 53 64 55 / 80 80 100 80
CAPULIN......................... 82 49 77 53 / 5 10 10 30
RATON........................... 83 49 79 54 / 5 10 10 30
SPRINGER........................ 84 50 78 55 / 10 10 20 40
LAS VEGAS....................... 75 50 70 54 / 30 20 40 60
CLAYTON......................... 86 58 82 59 / 5 5 10 20
ROY............................. 81 54 75 57 / 20 10 30 40
CONCHAS......................... 84 61 77 62 / 20 20 40 50
SANTA ROSA...................... 80 59 72 60 / 30 20 50 60
TUCUMCARI....................... 84 60 78 63 / 20 20 30 40
CLOVIS.......................... 78 61 73 62 / 40 30 50 50
PORTALES........................ 78 61 72 63 / 50 40 50 50
FORT SUMNER..................... 78 61 71 62 / 40 30 60 50
ROSWELL......................... 75 64 72 65 / 60 60 70 70
PICACHO......................... 70 60 68 60 / 70 60 80 80
ELK............................. 64 57 64 58 / 80 80 100 80
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ508-509-520-524>526-538>540.
&&
$$
41
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 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.
A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE SUNDAY... THEN
MOVE SOUTHEAST THROUGH THE REGION MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 950 PM THURSDAY...
A FEW SHOWERS OVER THE WESTERN PIEDMONT EARLIER THIS AFTERNOON HAVE
BECOME PRIMARILY FOCUSED OVER THE SOUTHERN PIEDMONT THIS EVENING.
AIDED BY WEAK TROUGH ALOFT APPROACHING FROM THE NORTHWEST...THE
SHOWERS SHOULD CONTINUE TO PERCOLATE WITHIN A RIDGE OF THETA-E AND
SOME SHALLOW INSTABILITY...ABOUT 500 J/KG MUCAPE... BELOW 600MB.
NOCTURNAL COOLING WILL SLOWLY ERODE THE CAPE AND INCREASE THE
CINH...BUT THE HRRR SUGGESTS SHOWERS MAY CONTINUE WELL PAST
MIDNIGHT. THE FREEZING LEVEL ON THE KGSO RAOB WAS AROUND 10K
FT...SO CANNOT RULE OUT AN ISOLATED THUNDERSTORM...THOUGH THIS WILL
BECOME LESS LIKELY AS THE NIGHT WEARS ON. HAVE INCREASED POPS OVER
THE SOUTHERN PIEDMONT TO LIKELY FOR THE NEXT FEW HOURS WITH A TREND
DOWNWARD AFTER 06Z. LOWS UPPER 50S/LOWER 60S NORTHEAST TO MID 60S SOUTHWEST.
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 /00Z FRIDAY THROUGH TUESDAY/...
AS OF 816 PM THURSDAY...
CONDITIONS ARE EXPECTED TO REMAIN VFR OVER THE NEXT 24 HOURS.
ISOLATED SHOWERS MAY AFFECT KINT...KGSO...AND KRDU FOR THE NEXT FEW
HOURS BEFORE DIMINISHING. WINDS WILL REMAIN LIGHT AND EAST TO
NORTHEASTERLY OVERNIGHT... BECOMING 5-10 KTS FRIDAY AFTERNOON.
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/BLS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...SEC/HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
817 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 /00Z FRIDAY THROUGH TUESDAY/...
AS OF 816 PM THURSDAY...
CONDITIONS ARE EXPECTED TO REMAIN VFR OVER THE NEXT 24 HOURS.
ISOLATED SHOWERS MAY AFFECT KINT...KGSO...AND KRDU FOR THE NEXT FEW
HOURS BEFORE DIMINISHING. WINDS WILL REMAIN LIGHT AND EAST TO
NORTHEASTERLY OVERNIGHT... BECOMING 5-10 KTS FRIDAY AFTERNOON.
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...SEC/HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
611 AM EDT WED SEP 17 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE EARLY THIS MORNING. HIGH PRESSURE
WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM WEDNESDAY...PRECIPITATION ASSOCIATED WITH A COLD
FRONT DROPPING SOUTH ACROSS THE FORECAST AREA HS MOSTLY PETERED
OUT THIS MORNING AS THE ATMOSPHERE HAS STABILIZED OUT. HAVE
LOWERED POPS TO SLIGHT CHANCE FOR THIS MORNING...REST OF FORECAST
REMAINS INTACT. PREVIOUS DISCUSSION FOLLOWS:
PRECIPITATION ASSOCIATED WITH A COLD FRONT DROPPING SOUTH ACROSS
THE FORECAST AREA IS MOVING EAST AND TRANSITIONING TO A MORE
STRATIFORM EVENT AS THE ATMOSPHERE CONTINUES TO STABILIZE.
HOWEVER..THERE IS STILL SOME SHOWER/THUNDERSTORM ACTIVITY AS AN
UPPER DISTURBANCE IMPINGES UPON THE AREA. THIS DISTURBANCE IS
INDUCING CYCLOGENESIS ALONG THE FRONT...LIKELY OVER OUR FAR
WESTERN COUNTIES...WHERE THE STRONGEST CONVECTION IS OCCURRING.
A CONSENSUS OF GUIDANCE JUMPS FRONT OFFSHORE AND SOUTH OF THE
EASTERN CAROLINAS BY DAYBREAK AS CYCLOGENESIS STRENGTHENS OFF THE
COAST. FOR THE REMAINDER OF THE DAY AND OVERNIGHT...THE COMBINATION
OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND LOW PRESSURE
OFFSHORE WILL BRING A SEASONALLY COOL EAST TO NORTHEASTERLY FLOW TO
THE AREA. HIGHS WILL RANGE FROM THE LOWER 80S UP NORTH TO THE MID
80S FURTHER SOUTH. WILL RETAIN THE LOW CHANCE OF CONVECTION TODAY
AND THIS EVENING AS MODEL SOUNDINGS INDICATE A MARGINALLY TO
MODERATELY UNSTABLE AIRMASS IN CONJUNCTION WITH A SERIES OF WEAK
UPPER IMPULSES DROPPING INTO THE BASE OF THE H/5 LONGWAVE TROUGH
LINGERING OVER EASTERN CONUS. A ADDITIONAL FACTOR FAVORING
PRECIPITATION TODAY WILL BE THE LOW LEVEL CONVERGENCE RESULTING FROM
WESTERLY WINDS ALOFT RIDING OVER EASTERLY WINDS BELOW.
OVERNIGHT LOWS WILL CONTINUE IN THE SEASONAL VEIN...WITH LOW RANGING
FROM THE LOWER 60S INLAND TO THE MID 60S CLOSER TO THE COAST AND
UPPER 60S AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SURFACE HIGH OVER THE GREAT LAKES THU WILL
SHIFT EAST TO NEW ENGLAND FRI...SETTING UP A CLASSIC WEDGE. LIGHT
NORTHEAST FLOW THU AND LIMITED LOW LEVEL MOISTURE MAY ALLOW FOR SOME
SUNSHINE BUT INCREASED NORTHEAST FLOW AND LOW LEVEL MOISTURE FRI
WILL LIKELY LEAD TO AN INCREASE IN CLOUD COVER. PRECIP CHANCES ARE
RATHER LIMITED EACH DAY WITH WEAK SUBSIDENCE ALOFT KEEPING THE MID
LEVELS DRY. THE ONLY REAL THREAT APPEARS TO BE ALONG THE IMMEDIATE
COAST WHERE LOW LEVEL MOISTURE IS HIGHEST...ESPECIALLY FRI...AND
SOME LIGHT RAIN COULD DEVELOP. MEASURABLE RAINFALL WILL BE DIFFICULT
TO COME BY EVEN IF LIGHT RAIN DEVELOPS SO PLAN TO CONTINUE CARRYING
SLIGHT CHC/LOW CHC ALONG THE COAST WITH POP AROUND 10 INLAND.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN AND A LITTLE LESS MARINE
INFLUENCE. LOW TEMPERATURES WILL END UP A LITTLE ABOVE CLIMO DUE TO
CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...HIGH PRESSURE WEDGE IN PLACE AT THE START OF
THE PERIOD WILL HOLD ON INTO AT LEAST THE SECOND HALF OF THE
WEEKEND...KEEPING TEMPERATURES IN MOST AREAS A LITTLE BELOW CLIMO.
GUIDANCE IS SHOWING HINTS THE WEDGE COULD HOLD ON INTO MON GIVEN THE
LACK OF SURFACE AND MID LEVEL FEATURES. THIS WOULD MAINTAIN LOW
CLOUDS AND LIGHT PRECIP...MAINLY ALONG THE COAST...INTO NEXT WEEK.
FARTHER INLAND THERE IS LIKELY TO BE A NARROW GRADIENT BETWEEN
MOSTLY CLOUDY AND MOSTLY SUNNY. THIS IS COMPLICATED SOMEWHAT BY
POTENTIAL WEAK LOW PRESSURE DEVELOPING ALONG THE FRONT STALLED
OFFSHORE. THIS FEATURE COULD ENHANCE THE WEDGE AS IT MOVES UP THE
COAST BEFORE HELPING TO BREAK THE WEDGE AS IT EXITS NORTHEAST.
HOWEVER ITS INFLUENCE ON THE AREA REMAINS IN QUESTION WITH MANY OF
THE MEDIUM RANGE SOLUTIONS KEEPING THIS FEATURE ON THE WEAK SIDE AND
FARTHER OFF THE COAST.
COLD FRONT APPROACHES FROM THE NORTHWEST MON...DRIVEN SOUTH BY
STRONG MID LEVEL TROUGH DIVING SOUTH ACROSS THE GREAT LAKES AND
CANADIAN HIGH PRESSURE. FROPA DURING THE DAY MON WILL HAVE SOME
DIURNAL INSTABILITY TO WORK WITH...BUT HOW MUCH REMAINS A QUESTION.
EXPECT CONVECTION AHEAD OF THE FRONT BUT STRENGTH AND COVERAGE WILL
PARTLY DEPEND ON TIMING. FRONT STALLS OFFSHORE MON NIGHT INTO
TUE...SIMILAR TO THIS WEEKS COLD FRONT AS SURFACE HIGH BUILDS IN
FROM THE GREAT LAKES.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE HRRR SUGGESTS SLOW-MOVING SHOWER/TSTM ACTIVITY
ALONG THE COLD FRONT MAY STILL PLAGUE OUR INLAND TAF SITES AT THE
START OF THE PERIOD. THEREFORE WILL INCLUDE VCSH FOR KFLO/KLBT
FROM 06-08Z. INCREASING DEBRIS CLOUDS FROM FRONTAL CONVECTION WILL
LIKELY LIMIT FOG POTENTIAL OVERNIGHT. HAVE JUST INCLUDED TEMPO
MVFR VSBYS... MAINLY EARLY IN THE PERIOD AS THE NORTHEASTERLY
SURGE AFTER 09Z OR SO SHOULD MIX OUT ANY LINGERING BR. COULD ALSO
SEE SOME MVFR CIGS DEVELOP BEHIND THE FRONT THIS MORNING...BUT IFR
POTENTIAL APPEARS LOW EVEN FOR THE INLAND TERMS. MVFR CIGS COULD
LINGER THROUGH THE LATE MORNING HOURS BEFORE IMPROVING TO VFR BY
MIDDAY. EXPECT NE WINDS AOB 10 KT BEHIND THE FRONT TO PERSIST
THROUGH THE PERIOD.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
A LIGHT EAST TO NORTHEASTERLY FLOW OF AROUND 10 KTS WILL DEVELOP
OVER THE WATERS TODAY AND TONIGHT AS A COLD FRONT DROPS SOUTH OF
THE AREA. WIND WAVES WILL BE IN THE MODEST 1 TO 2 FT RANGE...BUT
WILL BE SUPPLEMENTED BY SWELL FROM DISTANT HURRICANE
EDOUARD...BRINGING A COMBINED SEA HEIGHT RANGING FROM 2 TO 4 FT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...LIGHT NORTHEAST FLOW ON THU WILL INCREASE
SIGNIFICANTLY FRI AS HIGH PRESSURE BUILDS DOWN THE COAST AND
GRADIENT BECOMES PINCHED. THU NORTHEAST FLOW WILL BE IN THE REALM OF
10 KT BUT BY MIDDAY FRI SOLID 20 KT WITH HIGHER GUSTS IS EXPECTED.
SEAS 2 TO 4 FT THU FLIRTS WITH HEADLINE CRITERIA FRI...ESPECIALLY
NORTH OF CAPE FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT
ACROSS PARTS OF NC WATERS.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...ELEVATED NORTHEAST FLOW CONTINUES SAT AS
HIGH PRESSURE RIDGES DOWN THE COAST. GRADIENT WILL MAINTAIN 15 TO 20
KT WINDS SAT BUT WEAKENING GRADIENT SUN WILL ALLOW FOR A REDUCTION
IN SPEEDS. WEAK LOW PRESSURE PASSES EAST OF THE WATERS SUN. IN THE
WAKE OF THIS LOW SUN NIGHT LIGHT SOUTHWEST FLOW WILL DEVELOP. SEAS 3
TO 5 FT WITH OCCASIONAL 6 FT POSSIBLE SAT DECREASE TO 2 TO 4 FT SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...BJR
MARINE...REK/III
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
320 AM EDT WED SEP 17 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE EARLY THIS MORNING. HIGH PRESSURE
WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...PRECIPITATION ASSOCIATED WITH A COLD FRONT
DROPPING SOUTH ACROSS THE FORECAST AREA IS MOVING EAST AND
TRANSITIONING TO A MORE STRATIFORM EVENT AS THE ATMOSPHERE
CONTINUES TO STABILIZE. HOWEVER..THERE IS STILL SOME
SHOWER/THUNDERSTORM ACTIVITY AS AN UPPER DISTURBANCE IMPINGES UPON
THE AREA. THIS DISTURBANCE IS INDUCING CYCLOGENESIS ALONG THE
FRONT...LIKELY OVER OUR FAR WESTERN COUNTIES...WHERE THE STRONGEST
CONVECTION IS OCCURRING.
A CONSENSUS OF GUIDANCE JUMPS FRONT OFFSHORE AND SOUTH OF THE
EASTERN CAROLINAS BY DAYBREAK AS CYCLOGENESIS STRENGTHENS OFF THE
COAST. FOR THE REMAINDER OF THE DAY AND OVERNIGHT...THE COMBINATION
OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND LOW PRESSURE
OFFSHORE WILL BRING A SEASONALLY COOL EAST TO NORTHEASTERLY FLOW TO
THE AREA. HIGHS WILL RANGE FROM THE LOWER 80S UP NORTH TO THE MID
80S FURTHER SOUTH. WILL RETAIN THE LOW CHANCE OF CONVECTION TODAY
AND THIS EVENING AS MODEL SOUNDINGS INDICATE A MARGINALLY TO
MODERATELY UNSTABLE AIRMASS IN CONJUNCTION WITH A SERIES OF WEAK
UPPER IMPULSES DROPPING INTO THE BASE OF THE H/5 LONGWAVE TROUGH
LINGERING OVER EASTERN CONUS. A ADDITIONAL FACTOR FAVORING
PRECIPITATION TODAY WILL BE THE LOW LEVEL CONVERGENCE RESULTING FROM
WESTERLY WINDS ALOFT RIDING OVER EASTERLY WINDS BELOW.
OVERNIGHT LOWS WILL CONTINUE IN THE SEASONAL VEIN...WITH LOW RANGING
FROM THE LOWER 60S INLAND TO THE MID 60S CLOSER TO THE COAST AND
UPPER 60S AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SURFACE HIGH OVER THE GREAT LAKES THU WILL
SHIFT EAST TO NEW ENGLAND FRI...SETTING UP A CLASSIC WEDGE. LIGHT
NORTHEAST FLOW THU AND LIMITED LOW LEVEL MOISTURE MAY ALLOW FOR SOME
SUNSHINE BUT INCREASED NORTHEAST FLOW AND LOW LEVEL MOISTURE FRI
WILL LIKELY LEAD TO AN INCREASE IN CLOUD COVER. PRECIP CHANCES ARE
RATHER LIMITED EACH DAY WITH WEAK SUBSIDENCE ALOFT KEEPING THE MID
LEVELS DRY. THE ONLY REAL THREAT APPEARS TO BE ALONG THE IMMEDIATE
COAST WHERE LOW LEVEL MOISTURE IS HIGHEST...ESPECIALLY FRI...AND
SOME LIGHT RAIN COULD DEVELOP. MEASURABLE RAINFALL WILL BE DIFFICULT
TO COME BY EVEN IF LIGHT RAIN DEVELOPS SO PLAN TO CONTINUE CARRYING
SLIGHT CHC/LOW CHC ALONG THE COAST WITH POP AROUND 10 INLAND.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN AND A LITTLE LESS MARINE
INFLUENCE. LOW TEMPERATURES WILL END UP A LITTLE ABOVE CLIMO DUE TO
CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...HIGH PRESSURE WEDGE IN PLACE AT THE START OF
THE PERIOD WILL HOLD ON INTO AT LEAST THE SECOND HALF OF THE
WEEKEND...KEEPING TEMPERATURES IN MOST AREAS A LITTLE BELOW CLIMO.
GUIDANCE IS SHOWING HINTS THE WEDGE COULD HOLD ON INTO MON GIVEN THE
LACK OF SURFACE AND MID LEVEL FEATURES. THIS WOULD MAINTAIN LOW
CLOUDS AND LIGHT PRECIP...MAINLY ALONG THE COAST...INTO NEXT WEEK.
FARTHER INLAND THERE IS LIKELY TO BE A NARROW GRADIENT BETWEEN
MOSTLY CLOUDY AND MOSTLY SUNNY. THIS IS COMPLICATED SOMEWHAT BY
POTENTIAL WEAK LOW PRESSURE DEVELOPING ALONG THE FRONT STALLED
OFFSHORE. THIS FEATURE COULD ENHANCE THE WEDGE AS IT MOVES UP THE
COAST BEFORE HELPING TO BREAK THE WEDGE AS IT EXITS NORTHEAST.
HOWEVER ITS INFLUENCE ON THE AREA REMAINS IN QUESTION WITH MANY OF
THE MEDIUM RANGE SOLUTIONS KEEPING THIS FEATURE ON THE WEAK SIDE AND
FARTHER OFF THE COAST.
COLD FRONT APPROACHES FROM THE NORTHWEST MON...DRIVEN SOUTH BY
STRONG MID LEVEL TROUGH DIVING SOUTH ACROSS THE GREAT LAKES AND
CANADIAN HIGH PRESSURE. FROPA DURING THE DAY MON WILL HAVE SOME
DIURNAL INSTABILITY TO WORK WITH...BUT HOW MUCH REMAINS A QUESTION.
EXPECT CONVECTION AHEAD OF THE FRONT BUT STRENGTH AND COVERAGE WILL
PARTLY DEPEND ON TIMING. FRONT STALLS OFFSHORE MON NIGHT INTO
TUE...SIMILAR TO THIS WEEKS COLD FRONT AS SURFACE HIGH BUILDS IN
FROM THE GREAT LAKES.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE HRRR SUGGESTS SLOW-MOVING SHOWER/TSTM ACTIVITY
ALONG THE COLD FRONT MAY STILL PLAGUE OUR INLAND TAF SITES AT THE
START OF THE PERIOD. THEREFORE WILL INCLUDE VCSH FOR KFLO/KLBT
FROM 06-08Z. INCREASING DEBRIS CLOUDS FROM FRONTAL CONVECTION WILL
LIKELY LIMIT FOG POTENTIAL OVERNIGHT. HAVE JUST INCLUDED TEMPO
MVFR VSBYS... MAINLY EARLY IN THE PERIOD AS THE NORTHEASTERLY
SURGE AFTER 09Z OR SO SHOULD MIX OUT ANY LINGERING BR. COULD ALSO
SEE SOME MVFR CIGS DEVELOP BEHIND THE FRONT THIS MORNING...BUT IFR
POTENTIAL APPEARS LOW EVEN FOR THE INLAND TERMS. MVFR CIGS COULD
LINGER THROUGH THE LATE MORNING HOURS BEFORE IMPROVING TO VFR BY
MIDDAY. EXPECT NE WINDS AOB 10 KT BEHIND THE FRONT TO PERSIST
THROUGH THE PERIOD.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...A LIGHT EAST TO NORTHEASTERLY FLOW OF
AROUND 10 KTS WILL DEVELOP OVER THE WATERS TODAY AND TONIGHT AS A
COLD FRONT DROPS SOUTH OF THE AREA. WIND WAVES WILL BE IN THE
MODEST 1 TO 2 FT RANGE...BUT WILL BE SUPPLEMENTED BY SWELL FROM
DISTANT HURRICANE EDOUARD...BRINGING A COMBINED SEA HEIGHT RANGING
FROM 2 TO 4 FT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY....LIGHT NORTHEAST FLOW ON THU WILL INCREASE
SIGNIFICANTLY FRI AS HIGH PRESSURE BUILDS DOWN THE COAST AND
GRADIENT BECOMES PINCHED. THU NORTHEAST FLOW WILL BE IN THE REALM OF
10 KT BUT BY MIDDAY FRI SOLID 20 KT WITH HIGHER GUSTS IS EXPECTED.
SEAS 2 TO 4 FT THU FLIRTS WITH HEADLINE CRITERIA FRI...ESPECIALLY
NORTH OF CAPE FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT
ACROSS PARTS OF NC WATERS.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY....ELEVATED NORTHEAST FLOW CONTINUES SAT AS
HIGH PRESSURE RIDGES DOWN THE COAST. GRADIENT WILL MAINTAIN 15 TO 20
KT WINDS SAT BUT WEAKENING GRADIENT SUN WILL ALLOW FOR A REDUCTION
IN SPEEDS. WEAK LOW PRESSURE PASSES EAST OF THE WATERS SUN. IN THE
WAKE OF THIS LOW SUN NIGHT LIGHT SOUTHWEST FLOW WILL DEVELOP. SEAS 3
TO 5 FT WITH OCCASIONAL 6 FT POSSIBLE SAT DECREASE TO 2 TO 4 FT SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
119 AM EDT WED SEP 17 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE LATE TONIGHT. HIGH PRESSURE WILL
EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH BEHIND THIS
FRONT...PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK.
THE NEXT COLD FRONT WILL MOVE THROUGH BY MONDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:30 AM WEDNESDAY...LINE OF CONVECTION DROPPING FROM THE
NORTH BREAKING UP TO SOME EXTENT AND IS NOT AS STRONG/SOLID AS
BEFORE. THIS TREND WILL CONTINUE UNTIL ACTIVITY MOVES OFFSHORE IN
THE EARLY MORNING HOURS. PREVIOUS DISCUSSION FOLLOWS:
QUITE A LINE OF CONVECTION HAS DEVELOPED OVER THE PAST FEW HOURS
EXTENDING FROM THE SOUTH SIDE OF CHARLOTTE EASTWARD ACROSS
ROCKINGHAM...FAYETTEVILLE...AND APPROACHING CLINTON. SPC
MESOANALYSIS INDICATES SURFACE-BASED PARCELS ARE CAPPED...WHICH
MAKES SENSE GIVEN SURFACE TEMPERATURES IN THE LOWER 70S. ELEVATED
CAPE OF 750-1000 J/KG WITH MINIMAL CAPPING IS AVAILABLE WHEN
PARCELS AROUND 950-925 MB ARE CONSIDERED. MID-LEVEL LAPSE RATES
ARE RATHER STEEP AT 6 DEG C/KM. ALTHOUGH CONVECTION HAS MERGED
INTO A LINE EARLIER THERE WERE HINTS OF SUPER CELLULAR
CHARACTERISTICS AS A BELT OF STRONGER MID-LEVEL FLOW ACROSS NORTH-
CENTRAL NORTH CAROLINA IS PRODUCING 0-6 KM BULK SHEAR VALUES NEAR
30 KNOTS.
THE SURFACE COLD FRONT IS LOCATED 50-100 MILES BEHIND THE
CONVECTION...CURRENTLY EXTENDING ACROSS THE NORTHERNMOST ROW OF
COUNTIES IN NORTH CAROLINA. ALTHOUGH PRESSURES ARE CURRENTLY STEADY
ACROSS THE AREA WE ANTICIPATE FALLING PRESSURES TO DEVELOP ALONG THE
COAST AND OFFSHORE SHORTLY AS LOW PRESSURE DEVELOPS. THIS LOW WILL
PULL THE FRONT DOWN LATE TONIGHT AND OFFSHORE BY DAYBREAK.
SINCE THE CONVECTION IS ELEVATED AND BASED WITHIN A UNIFORM 950-900
MB LAYER IT SHOULD RESPOND MORE TO OVERALL SYNOPTIC FORCING THAN TO
ANYTHING GOING ON HERE AT THE SURFACE. THE UPPER DISTURBANCE IS
LOCATED NEAR I-77 NORTH OF CHARLOTTE AND SHOULD MOVE
EAST-NORTHEASTWARD THROUGH THE NIGHT. AS THE STORMS DRIFT SOUTH THEY
WILL MOVE OUT OF THE INFLUENCE OF THE UPPER TROUGH AND SHOULD
WEAKEN. THIS IS SHOWN BY THE 23Z RUN OF THE HRRR...WHICH ALSO
INDICATES THE CONVECTION MAY JUMP WILMINGTON AND
SOUTHPORT...REDEVELOPING OFFSHORE AFTER 2-3 A.M. WITHIN A REGION OF
SURFACE-BASED INSTABILITY OVER THE WARM OCEAN WATER.
NO CHANGES HAVE BEEN MADE TO FORECAST LOWS...STILL ANTICIPATED TO
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEAK LOW PRESSURE ALONG LINGERING FRONT
WILL GET PUSHED FARTHER OFF SHORE AS HIGH PRESSURE BUILDS DOWN
FROM THE NORTHWEST THROUGH MID WEEK. THE EASTERLY FLOW AROUND THE
TOP OF THE LOW WILL COME UP AGAINST W-NW FLOW AS HIGH PRESSURE
BUILDS IN. THIS WILL PRODUCE SOME LOW LEVEL CONVERGENCE THROUGH WED
AND THE LAST BIT OF ENERGY IN THE MID LEVELS WILL ROUND THE BASE
OF THE TROUGH BEFORE IT LIFTS OFF TO THE NORTHEAST. THEREFORE WILL
KEEP SOME CLOUDS AND POPS IN FORECAST ON WED. THE MID TO UPPER
TROUGH RUNNING DOWN THE EAST COAST WILL SHIFT SLOWLY EAST AND WILL
LIFT FARTHER OFF TO THE NORTHEAST WED INTO THURS. AS TROUGH AXIS
CROSSES THE COAST EARLY THURS...A DEEPER N-NW FLOW WILL ESTABLISH
ITSELF OVER THE CAROLINAS WITH CONSIDERABLE DRYING AND SUBSIDENCE
THROUGH THE MID LEVELS. HIGH PRESSURE WILL BUILD IN WITH LIGHT
NORTHERLY WINDS VEERING AROUND TO THE NE THROUGH LATE THURS. PCP
WATER VALUES DROP FROM AROUND 1.5 INCHES WED AFTN DOWN CLOSER TO
AN INCH BY THURS EVE. DEWPOINT TEMPS IN THE MID TO UPPER 60S WED
AFTN WILL DROP INTO THE LOWER 60S THROUGH THURS. OVERALL EXPECT
CONDITIONS TO IMPROVE WITH INCREASING SUNSHINE AND MORE FALL LIKE
WEATHER.
AS AIR MASS TRANSITIONS TO A DRIER MORE SEASONABLE AIR MASS...SO
WILL THE TEMPS. TEMPS OVERNIGHT WED WILL BE WARMER THAN THURS
NIGHT BY A COUPLE OF DEGREES...MID 60S BOTH NIGHTS. TEMPS WILL
REACH INTO THE 80S ON WED BUT ON THURS TEMPS WILL RUN A FEW
DEGREES COOLER EVEN WITH A GREATER AMOUNT OF SUNSHINE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...ON FRIDAY A LARGE AREA OF COOL HIGH PRESSURE
WILL BE SLIDING EAST ACROSS NEW ENGLAND. THIS ANTICYCLONE WILL HAVE
A RIDGE AXIS EXTENDING ALL THE WAY DOWN INTO THE CAROLINAS. FLOW
ALOFT WILL BE VERY WEAK BUT STILL HAVE SOME SENSE OF TROUGHINESS.
MODELS HAVING A HARD TIME TELLING HOW MUCH THIS TROUGHINESS ERODES
THE EASTERN PERIPHERY OF THE SURFACE RIDGE. THE MORE AGGRESSIVE GFS
MANAGES TO FLING MOISTURE ASHORE AND HAS THE SUPPORT OF THE CMC. THE
(00Z) ECMWF DOES THE SAME BUT WITH A MUCH SLOWER SENSE OF TIMING
KEEPING MOST PLACES DRY TIL SUNDAY. WILL SHOW JUST SLIGHT CHANCE
POPS ALONG THE COAST THROUGH THESE DAYS. THE WEDGE APPEARS TO WASH
OUT BY MONDAY AT WHICH TIME RAIN CHANCES SHIFT TO BEING TIED TO A
DEVELOPING PIEDMONT TROUGH AND TEMPS REBOUND TO NORMAL OR HIGHER. A
COLD FRONT APPEARS SLATED FOR A MONDAY NIGHT ARRIVAL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE HRRR SUGGESTS SLOW-MOVING SHOWER/TSTM ACTIVITY
ALONG THE COLD FRONT MAY STILL PLAGUE OUR INLAND TAF SITES AT THE
START OF THE PERIOD. THEREFORE WILL INCLUDE VCSH FOR KFLO/KLBT
FROM 06-08Z. INCREASING DEBRIS CLOUDS FROM FRONTAL CONVECTION WILL
LIKELY LIMIT FOG POTENTIAL OVERNIGHT. HAVE JUST INCLUDED TEMPO
MVFR VSBYS... MAINLY EARLY IN THE PERIOD AS THE NORTHEASTERLY
SURGE AFTER 09Z OR SO SHOULD MIX OUT ANY LINGERING BR. COULD ALSO
SEE SOME MVFR CIGS DEVELOP BEHIND THE FRONT THIS MORNING...BUT IFR
POTENTIAL APPEARS LOW EVEN FOR THE INLAND TERMS. MVFR CIGS COULD
LINGER THROUGH THE LATE MORNING HOURS BEFORE IMPROVING TO VFR BY
MIDDAY. EXPECT NE WINDS AOB 10 KT BEHIND THE FRONT TO PERSIST
THROUGH THE PERIOD.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS POSSIBLE ON THU.
GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS THE COOL AIR WEDGE
STRENGTHENS OVER THE CAROLINAS. VFR ON SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
WINDS ACROSS THE NC WATERS ARE GENERALLY FROM THE SOUTH OR
SOUTHEAST WITH A MORE VARIABLE PATTERN NOTED ACROSS THE SOUTH
CAROLINA WATERS. PRESSURES SHOULD BEGIN TO FALL SHORTLY ALONG THE
COAST AS LOW PRESSURE DEVELOPS OFFSHORE. THIS LOW WILL PULL THE
COLD FRONT...CURRENTLY ACROSS NORTHERN NORTH CAROLINA...SOUTHWARD
AND OFF THE COAST BY DAYBREAK WITH NORTHERLY WINDS EXPECTED TO
DEVELOP. A LINE OF THUNDERSTORMS ACROSS THE INTERIOR COASTAL PLAIN
WILL PROBABLY WEAKEN BEFORE MAKING IT TO THE BEACHES...HOWEVER
CONDITIONS FAVOR THE DEVELOPMENT OF SCATTERED THUNDERSTORMS OUT
AHEAD OF THIS LINE AFTER MIDNIGHT...MOST LIKELY IN THE 2-4 AM TIME
FRAME. SEAS CURRENTLY 1-2 FT MAY BEGIN TO BUILD TOWARD 3 FEET
ACROSS THE OUTERMOST PORTION OF THE COASTAL WATERS LATE TONIGHT AS
SWELL FROM DISTANT HURRICANE EDOUARD FINALLY MAKES IT TO THE
COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WILL MAINTAIN E-NE WINDS THROUGH MID WEEK
AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH. INITIALLY WINDS WILL
BE LIGHTER AND MORE EASTERLY. THE ON SHORE FLOW UP TO 10 KTS ON
WED WILL COMBINE WITH THE SEA BREEZE AND A LONG PERIOD UP TO 16
SEC EASTERLY SWELL TO PUSH SEAS UP TO 2 TO 4 FT WITH SOME 5 FTERS
IN OUTER WATERS WED AFTN. THE LONGER PERIOD EASTERLY SWELLS FROM
EDOUARD WELL OUT IN THE ATLANTIC WATERS WILL PEAK AROUND 16
SECONDS VERY EARLY WED AND WILL DIMINISH SLOWLY THROUGH THURS.
SEAS WILL ACTUALLY DROP SLIGHTLY THROUGH EARLY THURS BUT A SLIGHT
INCREASE IN NE WINDS UP TO 10-15 KNOTS THROUGH THUR NIGHT SHOULD
PRODUCE ANOTHER SPIKE IN SEAS BY FRI MORNING.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A WEDGE OF HIGH PRESSURE MORE REMINISCENT OF
THE COOL SEASON WILL DEVELOP ON FRIDAY. THE PINCHED NORTHEASTERLY
GRADIENT COULD YIELD A FEW ADVISORY-WORTHY 6 FT SEAS INTO NRN
ZONES...BUT WNA GUIDANCE HAS COME DOWN FROM PREVIOUS RUNS AND IT
MAY BE QUITE MARGINAL. CURRENT FCST STILL SHOWING A RAMP UP TO 4
TO 6 THOUGH. WAVE SHADOWING WILL PRECLUDE ADVISORY OVER SOUTHERN
WATERS. A MODERATE NORTHEASTERLY FLOW WILL REMAIN IN PLACE FOR THE
REST OF THE PERIOD WITH A GRADUAL DECREASE IN STRENGTH. BORDERLINE
SCEC/ADVISORY MAY CONTINUE OVER NRN ZONES INTO SATURDAY. FURTHER
WEAKENING OF THE HIGH PRESSURE WILL BRING QUIETER CONDITIONS COME
SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...REK/RJD/TRA
SHORT TERM...RGZ
LONG TERM...MBB
AVIATION...BJR
MARINE...REK/RJD/TRA/MBB/RGZ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
936 PM CDT THU SEP 18 2014
.UPDATE...
ISSUED AT 936 PM CDT THU SEP 18 2014
FORECAST REMAINS ON TRACK FOR THE LATE EVENING UPDATE. MAIN
MODIFICATIONS WERE TO POPS...TO ACCOUNT FOR THE EASTWARD
PROGRESSION OF CURRENT SHOWER ACTIVITY ACROSS THE SOUTH
CENTRAL...AND FOR A LARGE AREA OF SHOWERS/ISOLD THUNDER ACROSS
SOUTHEASTERN MONTANA MOVING EAST-NORTHEAST TOWARDS MY SOUTHWEST.
UPDATE
ISSUED AT 710 PM CDT THU SEP 18 2014
ROBUST CAPPING INVERSION KEEPING A LID ON STRONG CONVECTION EARLY
THIS EVENING ACROSS WESTERN AND CENTRAL NORTH DAKOTA DESPITE 1-2K
JOULES OF CAPE AND STRONG 0-6KM WIND SHEAR OF 40-45KTS. AN AREA OF
ELEVATED SHOWERS OVER THE SOUTHWESTERN QUARTER OF NORTH
DAKOTA...ASSOCIATED WITH A MID LEVEL IMPULSE...CONTINUES EASTWARD.
MODIFIED POPS BASED ON LATEST RADAR AND NEAR TERM HR MODEL
OUTPUT...TAKING THIS AREA OF PRECIPITATION EAST-NORTHEAST OVER THE
NEXT SEVERAL HOURS. GIVEN THE INSTABILITY PRESENT WILL MENTION AT
LEAST AN ISOLATED THUNDERSTORM CHANCE.
MID LEVEL SHORT WAVE APPROACHING THE INTERMOUNTAIN WEST AND
FORECAST TO MOVE EAST ACROSS THE NORTHERN PLAIN FRIDAY MORNING WILL
BRING A CONTINUED CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS THE LOCAL AREA OVERNIGHT TONIGHT THROUGH FRIDAY MORNING.
&&
.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 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 710 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 SHOWERS
AND THUNDERSTORMS WILL BE ASSOCIATED WITH THE WARM FRONT ACROSS
CENTRAL NORTH DAKOTA THIS EVENING. THE COLD FRONT WILL BE THE
FOCUS FOR SHOWERS AND THUNDERSTORMS ACROSS WEST AND CENTRAL
TONIGHT INTO FRIDAY MORNING...AND ACROSS NORTHERN NORTH DAKOTA
FRIDAY AFTERNOON. GIVEN THE STRONG CAPPING INVERSION...OPTED TO
USE VCSH AS THE OVERALL THUNDERSTORM THREAT WILL BE ISOLATED AT
BEST. OVERALL VFR IS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...WAA
LONG TERM...JV
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
710 PM CDT THU SEP 18 2014
.UPDATE...
ISSUED AT 710 PM CDT THU SEP 18 2014
ROBUST CAPPING INVERSION KEEPING A LID ON STRONG CONVECTION EARLY
THIS EVENING ACROSS WESTERN AND CENTRAL NORTH DAKOTA DESPITE 1-2K
JOULES OF CAPE AND STRONG 0-6KM WIND SHEAR OF 40-45KTS. AN AREA OF
ELEVATED SHOWERS OVER THE SOUTHWESTERN QUARTER OF NORTH
DAKOTA...ASSOCIATED WITH A MID LEVEL IMPULSE...CONTINUES EASTWARD.
MODIFIED POPS BASED ON LATEST RADAR AND NEAR TERM HR MODEL
OUTPUT...TAKING THIS AREA OF PRECIPITATION EAST-NORTHEAST OVER THE
NEXT SEVERAL HOURS. GIVEN THE INSTABILITY PRESENT WILL MENTION AT
LEAST AN ISOLATED THUNDERSTORM CHANCE.
MID LEVEL SHORT WAVE APPROACHING THE INTERMOUNTAIN WEST AND
FORECAST TO MOVE EAST ACROSS THE NORTHERN PLAIN FRIDAY MORNING WILL
BRING A CONTINUED CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS THE LOCAL AREA OVERNIGHT TONIGHT THROUGH FRIDAY MORNING.
&&
.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 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 710 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 SHOWERS
AND THUNDERSTORMS WILL BE ASSOCIATED WITH THE WARM FRONT ACROSS
CENTRAL NORTH DAKOTA THIS EVENING. THE COLD FRONT WILL BE THE
FOCUS FOR SHOWERS AND THUNDERSTORMS ACROSS WEST AND CENTRAL
TONIGHT INTO FRIDAY MORNING...AND ACROSS NORTHERN NORTH DAKOTA
FRIDAY AFTERNOON. GIVEN THE STRONG CAPPING INVERSION...OPTED TO
USE VCSH AS THE OVERALL THUNDERSTORM THREAT WILL BE ISOLATED AT
BEST. OVERALL VFR IS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...WAA
LONG TERM...JV
AVIATION...NH
AREA FORECAST DISCUSSION
NWS TULSA OK
640 AM CDT WED SEP 17 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FLIGHT CONDITIONS WILL BE HIGHLY VARIABLE THE FIRST COUPLE HOURS
OF THE FORECAST PERIOD DUE TO AREAS OF LOW CLOUDS AND FOG.
CONDITIONS SHOULD IMPROVE TO VFR BY MIDDAY AT ALL SITES. SCATTERED
SHOWERS AND THUNDERSTORMS WILL AFFECT MAINLY THE NORTHWEST
ARKANSAS SITES LATE THIS AFTERNOON AND TONIGHT. AREAS OF LOW
CLOUDS AND LIGHT FOG MAY DEVELOP AGAIN LATE TONIGHT RESULTING IN
MVFR CONDITIONS AT TIMES.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT WED SEP 17 2014/
DISCUSSION...
THUNDERSTORMS HAVE BLOSSOMED OVER EASTERN KANSAS WITHIN THE PAST
HOUR OR TWO IN RESPONSE TO A DISTURBANCE IN THE CENTRAL PLAINS AND
THE APPROACH OF A STRONG UPPER JET. MOVEMENT OF THE CURRENT
ACTIVITY CONFIRMS THE LOCAL WRF AND HRRR SOLUTIONS THAT KEEP THE
BULK OF THIS NORTH OF THE OKLAHOMA AND ARKANSAS BORDERS UNTIL THIS
AFTERNOON. WILL CONTINUE WITH SMALL POPS IN FAR NORTHEAST OKLAHOMA
AND FAR NORTHWEST ARKANSAS THROUGH THE MORNING HOURS...WITH HIGHER
CHANCES THIS AFTERNOON AND INTO TONIGHT. ONGOING PATCHY BUT
OCCASIONALLY DENSE FOG IN NORTHWEST ARKANSAS SHOULD BE GONE
SHORTLY AFTER SUNRISE. PER SURFACE OBS...VISIBILITIES HAVE VARIED
WILDLY THIS MORNING AT ANY ONE LOCATION WHICH COULD MAKE FOR A
DIFFICULT COMMUTE ESPECIALLY IN THE BENTON AND WASHINGTON
COUNTIES. AFTERNOON TEMPERATURES TODAY LOOK TO BE ABOVE NORMAL IN
MOST AREAS...WITH SOME SPOTS ALONG AND WEST OF HIGHWAY 75 LIKELY
TO TOUCH 90 DEGREES.
ANOTHER ROUND OF THUNDERSTORMS SHOULD DEVELOP AND AFFECT A BIGGER
SECTION OF EASTERN OKLAHOMA AND WESTERN ARKANSAS LATE TONIGHT AND
PERHAPS INTO TOMORROW AS ANOTHER SEGMENT OF THE UPPER JET
STRENGTHENS TO OUR EAST AND A DISTURBANCE MOVES THROUGH MISSOURI
AND ARKANSAS. A BRIEF DRYING TREND STILL APPEARS TO BE IN THE
OFFING FOR FRIDAY AND INTO FRIDAY NIGHT...AS UPPER RIDGING QUICKLY
BUILDS INTO THE PLAINS.
THE PATTERN WILL REMAIN FAIRLY PROGRESSIVE...HOWEVER...AS A STRONG
COLD FRONT IS STILL ON TRACK FOR THE WEEKEND. WITH THE REMNANTS OF
ODILE MOVING INTO THE REGION...A HEAVY RAIN EVENT CONTINUES TO
LOOK LIKELY SOMEWHERE IN THE SOUTHERN OR CENTRAL PLAINS. WITH THE
EXCEPTION OF YESTERDAYS 12Z RUN OF THE ECMWF...MOST MEDIUM RANGE
MODEL SOLUTIONS STILL PLACE THE HEAVY RAIN AXIS TO OUR
NORTH...WHILE STILL ALLOWING FOR SOME BENEFICIAL RAIN AMOUNTS
ACROSS PARTS OF NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS.
TIMING OF THE HEAVIEST RAIN CURRENTLY LOOKS TO BE BETWEEN 18Z
SATURDAY AND 06Z SUNDAY. THE RAIN SHOULD CLEAR QUICKLY ENOUGH TO
ALLOW FOR A DRY BUT COOL BEGINNING TO NEXT WEEK.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS TULSA OK
333 AM CDT WED SEP 17 2014
.DISCUSSION...
THUNDERSTORMS HAVE BLOSSOMED OVER EASTERN KANSAS WITHIN THE PAST
HOUR OR TWO IN RESPONSE TO A DISTURBANCE IN THE CENTRAL PLAINS AND
THE APPROACH OF A STRONG UPPER JET. MOVEMENT OF THE CURRENT
ACTIVITY CONFIRMS THE LOCAL WRF AND HRRR SOLUTIONS THAT KEEP THE
BULK OF THIS NORTH OF THE OKLAHOMA AND ARKANSAS BORDERS UNTIL THIS
AFTERNOON. WILL CONTINUE WITH SMALL POPS IN FAR NORTHEAST OKLAHOMA
AND FAR NORTHWEST ARKANSAS THROUGH THE MORNING HOURS...WITH HIGHER
CHANCES THIS AFTERNOON AND INTO TONIGHT. ONGOING PATCHY BUT
OCCASIONALLY DENSE FOG IN NORTHWEST ARKANSAS SHOULD BE GONE
SHORTLY AFTER SUNRISE. PER SURFACE OBS...VISIBILITIES HAVE VARIED
WILDLY THIS MORNING AT ANY ONE LOCATION WHICH COULD MAKE FOR A
DIFFICULT COMMUTE ESPECIALLY IN THE BENTON AND WASHINGTON
COUNTIES. AFTERNOON TEMPERATURES TODAY LOOK TO BE ABOVE NORMAL IN
MOST AREAS...WITH SOME SPOTS ALONG AND WEST OF HIGHWAY 75 LIKELY
TO TOUCH 90 DEGREES.
ANOTHER ROUND OF THUNDERSTORMS SHOULD DEVELOP AND AFFECT A BIGGER
SECTION OF EASTERN OKLAHOMA AND WESTERN ARKANSAS LATE TONIGHT AND
PERHAPS INTO TOMORROW AS ANOTHER SEGMENT OF THE UPPER JET
STRENGTHENS TO OUR EAST AND A DISTURBANCE MOVES THROUGH MISSOURI
AND ARKANSAS. A BRIEF DRYING TREND STILL APPEARS TO BE IN THE
OFFING FOR FRIDAY AND INTO FRIDAY NIGHT...AS UPPER RIDGING QUICKLY
BUILDS INTO THE PLAINS.
THE PATTERN WILL REMAIN FAIRLY PROGRESSIVE...HOWEVER...AS A STRONG
COLD FRONT IS STILL ON TRACK FOR THE WEEKEND. WITH THE REMNANTS OF
ODILE MOVING INTO THE REGION...A HEAVY RAIN EVENT CONTINUES TO
LOOK LIKELY SOMEWHERE IN THE SOUTHERN OR CENTRAL PLAINS. WITH THE
EXCEPTION OF YESTERDAYS 12Z RUN OF THE ECMWF...MOST MEDIUM RANGE
MODEL SOLUTIONS STILL PLACE THE HEAVY RAIN AXIS TO OUR
NORTH...WHILE STILL ALLOWING FOR SOME BENEFICIAL RAIN AMOUNTS
ACROSS PARTS OF NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS.
TIMING OF THE HEAVIEST RAIN CURRENTLY LOOKS TO BE BETWEEN 18Z
SATURDAY AND 06Z SUNDAY. THE RAIN SHOULD CLEAR QUICKLY ENOUGH TO
ALLOW FOR A DRY BUT COOL BEGINNING TO NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 89 69 88 69 / 10 30 30 10
FSM 86 68 85 67 / 20 40 40 10
MLC 88 71 87 68 / 10 20 30 10
BVO 90 67 87 67 / 10 40 30 10
FYV 83 65 83 64 / 30 60 40 10
BYV 82 64 80 64 / 50 60 40 10
MKO 87 68 86 67 / 10 20 40 10
MIO 85 67 84 66 / 50 60 40 10
F10 87 69 87 68 / 10 20 30 10
HHW 88 70 88 68 / 10 20 40 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...05
LONG TERM....22
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
401 PM CDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
PICTURE PERFECT WEATHER CONDITIONS ACROSS THE REGION THIS AFTERNOON
AS TEMPERATURES HAVE RISEN INTO THE 70S AND WINDS REMAIN LIGHT.
ONLY MINOR FORECAST CONCERNS THROUGH THE DAYBREAK HOURS. MINOR
SHORTWAVE OVER EASTERN MONTANA WILL DROP SOUTHEAST LATER THIS
EVENING. LATEST HRRR AND HOPWRF RUNS INDICATING THIS WAVE SHOULD
BEGIN PRODUCING WIDELY SCATTERED SHOWERS AS IT MOVES INTO THE AREA.
GENERALLY THESE WILL BE HIGH-BASED SHOWERS...AND GIVEN A RATHER
SUBSTANTIAL DRY SUB-CLOUD LAYER...ANTICIPATE A CONSIDERABLE
AMOUNT OF VIRGA OR A FEW SPRINKLES MAINLY WEST OF I-29 THROUGH
MIDNIGHT.
THE PASSAGE OF THIS UPPER WAVE WILL ALLOW A WEAK SURFACE BOUNDARY TO
DRIFT NORTHWARD EARLY TOMORROW MORNING..WITH LOW-LEVEL MOISTURE
STEADILY ADVECTING NORTHWARD. SHOULD SEE STRATUS DEVELOPMENT TOWARDS
DAYBREAK...AND CANNOT RULE OUT PATCHY FOG ESPECIALLY ALONG EDGE OF
ADVANCING STRATUS. LOW LEVEL ISENTROPIC PLOTS SHOW VERY WEAK LIFT
WITHIN THE CLOUD LAYER...BUT FEEL LIFT TOO WEAK TO SUPPORT DRIZZLE.
CLOUDS ARE EXPECTED TO HANG AROUND FOR MUCH OF THURSDAY...GRADUALLY
LIFTING AND SCATTERING IN THE AFTERNOON. TEMPERATURES WILL REMAIN
IN THE 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 306 PM CDT WED SEP 17 2014
LITTLE DOUBT THAT EXTENSIVE STRATUS WILL EXPAND/DEVELOP THURSDAY
NIGHT INTO EARLY FRIDAY WITH ENHANCED LOW LEVEL JET AND STRENGTHENING
INVERSION. FOG A BIT MORE PROBLEMATIC...LIKELY FAVORING WESTERN
EDGE OF THE CLOUD AREA...AND NEAR SURFACE SOUTHEAST TO SOUTH FLOW
PROVIDING INCREASING MOISTURE. SREF PROBABILITIES OF LOW CLOUDS
ARE EXTREMELY HIGH...BUT MODEST IN THE REALM OF LOWEST
VISIBILITIES...GENERALLY SUPPORTING THIS EXPECTATION. NOT TOO
ENTHUSIASTIC ABOUT PRECIPITATION CHANCES...ESPECIALLY IN THE
EVENING. A LITTLE ENHANCEMENT OF LIFT ON LEADING EDGE OF THE
WARMING TEMPS ALOFT OCCURS ACROSS NORTHEAST NEBRASKA BY AROUND
06Z...AND COULD BE JUST ENOUGH ELEVATED FORCING AND WEAK
INSTABILITY TO SHAKE OUT AN ISOLATED THUNDERSTORM HEADING THROUGH
SOUTHWEST MINNESOTA AND NORTHWEST IOWA ALONG ELEVATED THETA E
ADVECTION ZONE.
IF NOT FOR A MINIMAL CHANCE OF A SHOWER OR THUNDERSTORM LINGERING
EARLY FRIDAY IN THE FAR EAST/NORTHEAST...FRIDAY WILL BE A CAPPED
DAY AS TEMPS 800-750 HPA TEMPS WARM TO +15 TO +22C...WITH THE
MAIN BATTLE OF THE DAY OVER MAX TEMPERATURES SET BETWEEN THE
STRATUS AND THE SOUTHWESTERLY FLOW ALOFT. TREND HAS BEEN TO SLOW
DOWN THE EASTWARD PROGRESSION...WITH EARLY DAY CLOUDS AT LEAST
BACK TO WEST OF THE JAMES RIVER...AND PERHAPS HOLDING TOUGH INTO
VERY EARLY AFTERNOON TOWARD I 29. SHOULD EVENTUALLY CLEAR WITH
GOOD PUSH FROM WESTERLY COMPONENT AHEAD OF ADVANCING FRONTAL ZONE
REACHING THE FAR WESTERN CWA BY LATE DAY. ENOUGH INTERFERENCE
EARLY IN THE DAY EAST TO HOLD READINGS CLOSER TO 80 DEGREES...BUT
SOME AREAS TO THE WEST TOWARD LOWER JAMES AND LOWER BRULE WILL
GIVE A GOOD RUN AT UPPER 80S TO NEAR 90.
PRECIPITATION SHOULD BE EXCLUSIVELY POST FRONTAL ON FRIDAY
NIGHT...SOMEWHAT SCARCE EARLY ON...BUT GRADUALLY TAKING HOLD WITH
DEEPER POST FRONTAL QG LIFT...AND PERHAPS A LITTLE MID LEVEL
WEAK CONTRIBUTION TO MOISTURE BY THE TIME DEFORMATION REACHES THE
SOUTHEASTERN HALF OF THE CWA LATER AT NIGHT. NOT LOOKING FOR ANY
SEVERE STORMS WITH INSTABILITY LIMITED...AND EFFECTIVE SHEAR
REDUCED BY NOCTURNAL DECOUPLING AND THE DEGREE OF WESTERLY
PREFRONTAL COMPONENT.
BEHIND ANY LINGERING SHOWERS/THUNDER SATURDAY MORNING...LOOKS TO
BE A WELL-MIXED DAY...AND WITH MAIN COOLING HOLDING OFF UNTIL
SECONDARY WAVE PASSAGE TO THE EAST ON SATURDAY EVENING... WILL
LIKELY BE A FAIRLY WARM DAY...AND LAST ABOVE NORMAL FOR A FEW
DAYS. MIXING WOULD FAVOR MAINLY UPPER 70S TO LOWER 80S...ALONG
WITH BRISK MIDDAY AND AFTERNOON WINDS OF 15 TO 25 MPH.
FOR SUNDAY THROUGH WEDNESDAY...LOOKS LIKE A FAIRLY QUIET TIME
AS FLOW AMPLIFIES A BIT INTO EARLY WEEK WITH WESTERN RIDGE AND
EASTERN TROUGH...THEN WEAKENS AND TRANSLATES EASTWARD AS SEVERAL
SOLUTIONS INDICATE A WESTERN TROUGH PROGRESSING INTO THE AREA BY
LATER TUESDAY OR EARLY WEDNESDAY. WOULD NOT BE SURPRISED TO NEED
TO ADD IN A THREAT FOR SHOWER/THUNDER FOR TUESDAY NIGHT INTO
WEDNESDAY...BUT TIMING AND LOCATION OF UPPER TROUGH IN FLUX AT
THIS POINT AND NOT WORTH CLUTTERING UP THE FORECAST...ESPECIALLY
CONSIDERING THE RUN TO RUN SIGNIFICANT CHANGES IN MODELS OVER LAST
24 HOURS. STRETCHED OUT DIURNAL RANGE JUST A TOUCH ON MONDAY AND
TUESDAY WITH DRY SURFACE RIDGE SLIPPING THROUGH THE AREA...AND
MAINTAINING A TRAJECTORY INTO THE EAST ON TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1159 AM CDT WED SEP 17 2014
EASTERLY WINDS WILL PREVAIL INTO THE EVENING HOURS...BEFORE
TURNING MORE SOUTHERLY AFTER MIDNIGHT. SCATTERED CU FIELD LIKELY
THIS AFTERNOON...WITH MODELS SUGGESTING A SCATTERED 10K FT AGL
DECK MOVING IN THIS EVENING AS WEAK SHORTWAVE PASSES THROUGH.
MODELS STILL SUGGEST LOW LEVEL MVFR/IFR STRATUS DEVELOPING TOWARD
DAYBREAK WITH LOCALIZED MVFR VISIBILITY RESTRICTIONS...WHICH WILL
GRADUALLY LIFT THROUGH THE MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...DUX
LONG TERM...CHAPMAN
AVIATION...DUX
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1031 PM CDT THU SEP 18 2014
.DISCUSSION...
IMPULSE CONTINUES TO WORK SOUTHWARD ACROSS WESTERN TN. LATEST IR
IMAGERY SHOWS A SLIGHT NORTHWARD JOG IN REGARD TO THE COOLER CLOUD
TOPS/ REFLECTIVITY LOOP ALSO SHOWS A FEW SHOWERS MAKING INTO OUR
FAR SW. WILL GO AHEAD AND UPDATE FCST AND INCLUDE A SLIGHT CHANCE
OF SHOWERS ACROSS OUR FAR SOUTHWEST. THE ACTIVITY SHOULD FINALLY
SLIP SOUTH OF OUR AREAS AFTER MIDNIGHT.
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT THU SEP 18 2014/
DISCUSSION...
WILL REMOVE THE EVENING POPS ACROSS THE SOUTHWESTERN ZONES. THE
ACTIVITY IS WELL TO THE SOUTH OF THE AREA AND THE HRRR HAS
SIGNALED NO ADDITIONAL OVERNIGHT DEVELOPMENT. OTW...UPDATE WILL
REMOVE THE AFT WORDING. REMAINDER OF FCST IN GOOD SHAPE.
PREV DISCUSSION... /ISSUED 613 PM CDT THU SEP 18 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
MAYBE SOME ISO SHWRS W/SW OF TAF SITES THRU 19/03Z...BUT NO FORMATION/IMPACTS
AT TAF SITES EXPECTED. GENERALLY DRIER AIR IS EXPECTED TO WORK INTO MID STATE
THRU 19/24Z...BUT EXPECT CKV/CSV TO STILL EXPERIENCE MVFR FOG...TEMPO IFR FOG
CSV...19/10Z-19/14Z. RIDGING INFLUENCES SFC/ALOFT SHOULD PROVIDE FOR SOME
SCT DIURNAL CU DEVELOPMENT 19/15Z-19/24Z.
PREV DISCUSSION.../ISSUED 242 PM CDT THU SEP 18 2014/
DISCUSSION...ACTIVE WEATHER OCCURRING OVER THE SW CORNER OF
MIDDLE TENNESSEE, WHERE LOW-LEVEL MOISTURE AND INSTABILITY ARE
GREATEST. MAY SEE A FEW SHOWERS LINGER THERE INTO THE EARLY
EVENING. OTHERWISE, SURFACE HIGH PRESSURE CENTERED OVER THE GREAT
LAKES CONTINUES TO INFLUENCE OUR WEATHER. UPPER TROUGH IS NOW
SITUATED TO OUR EAST, WITH A NW FLOW ALOFT. AT THE SURFACE, LOOK
FOR TEMPERATURES TO CONTINUE WARMING AS WE HEAD INTO THE WEEKEND.
THE NEXT SURFACE FRONT WILL ENTER MIDDLE TENNESSEE FROM THE NW
SATURDAY NIGHT OR SUNDAY MORNING, WITH MAINLY SCATTERED POP`S WITH
THE FRONT. FORECAST SOUNDINGS DO SHOW SOME INSTABILITY WITH THIS
SYSTEM, SO WILL INCLUDE THUNDERSTORMS IN THE FORECAST. LOOK FOR
SLIGHTLY COOLER TEMPERATURES HEADING INTO NEXT WEEK WITH VERY
LITTLE CHANCE OF PRECIPITATION MONDAY THRU THURSDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
650 PM CDT THU SEP 18 2014
.DISCUSSION...
WILL REMOVE THE EVENING POPS ACROSS THE SOUTHWESTERN ZONES. THE
ACTIVITY IS WELL TO THE SOUTH OF THE AREA AND THE HRRR HAS
SIGNALED NO ADDITIONAL OVERNIGHT DEVELOPMENT. OTW...UPDATE WILL
REMOVE THE AFT WORDING. REMAINDER OF FCST IN GOOD SHAPE.
&&
.PREV DISCUSSION... /ISSUED 613 PM CDT THU SEP 18 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
MAYBE SOME ISO SHWRS W/SW OF TAF SITES THRU 19/03Z...BUT NO FORMATION/IMPACTS
AT TAF SITES EXPECTED. GENERALLY DRIER AIR IS EXPECTED TO WORK INTO MID STATE
THRU 19/24Z...BUT EXPECT CKV/CSV TO STILL EXPERIENCE MVFR FOG...TEMPO IFR FOG
CSV...19/10Z-19/14Z. RIDGING INFLUENCES SFC/ALOFT SHOULD PROVIDE FOR SOME
SCT DIURNAL CU DEVELOPMENT 19/15Z-19/24Z.
PREV DISCUSSION.../ISSUED 242 PM CDT THU SEP 18 2014/
DISCUSSION...ACTIVE WEATHER OCCURRING OVER THE SW CORNER OF
MIDDLE TENNESSEE, WHERE LOW-LEVEL MOISTURE AND INSTABILITY ARE
GREATEST. MAY SEE A FEW SHOWERS LINGER THERE INTO THE EARLY
EVENING. OTHERWISE, SURFACE HIGH PRESSURE CENTERED OVER THE GREAT
LAKES CONTINUES TO INFLUENCE OUR WEATHER. UPPER TROUGH IS NOW
SITUATED TO OUR EAST, WITH A NW FLOW ALOFT. AT THE SURFACE, LOOK
FOR TEMPERATURES TO CONTINUE WARMING AS WE HEAD INTO THE WEEKEND.
THE NEXT SURFACE FRONT WILL ENTER MIDDLE TENNESSEE FROM THE NW
SATURDAY NIGHT OR SUNDAY MORNING, WITH MAINLY SCATTERED POP`S WITH
THE FRONT. FORECAST SOUNDINGS DO SHOW SOME INSTABILITY WITH THIS
SYSTEM, SO WILL INCLUDE THUNDERSTORMS IN THE FORECAST. LOOK FOR
SLIGHTLY COOLER TEMPERATURES HEADING INTO NEXT WEEK WITH VERY
LITTLE CHANCE OF PRECIPITATION MONDAY THRU THURSDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1239 PM CDT WED SEP 17 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...A LITTLE STRONGER SOUTHERLY FLOW IS PRODUCING AN
EXTENSIVE CUMULUS FIELD ALONG AND EAST HIGHWAY 77. FLIGHT
CATEGORIES ARE DOMINATE VFR WITHIN THIS CLOUD FIELD BUT COULD
BRIEFLY TOUCH MVFR AROUND 2500-3000 FEET. ISOLATED CONVECTION IS
POSSIBLE BUT CHANCES HAVE BEEN REDUCED THIS AFTERNOON BUT REMAIN
HIGHEST ALONG AND EAST OF THE COASTLINE. WESTERN AREAS WILL
EXPERIENCE GOOD FLYING CONDITIONS WITH FEW-SCT CLOUDS. WEAK
SURFACE INVERSION DEVELOPS OVERNIGHT WITH STRATUS DEVELOPING LATE
OR A FEW HOURS EITHER SIDE OF SUNRISE. BEST PROBABILITIES FOR MVFR
CIGS WILL BE WEST OF HIGHWAY 77 WITH BRIEF IMPACTS AT KMFE AND
POSSIBLY AT KHRL THURSDAY MORNING. MODERATE SOUTH TO SOUTHEAST
WINDS THIS AFTERNOON AND INTO THE EVENING WITH SOME GUSTS
APPROACHING 20 KNOTS MAYBE A LITTLE STRONGER THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1133 AM CDT WED SEP 17 2014/
DISCUSSION...REDUCED POPS FOR THIS AFTERNOON WITH HIGH PRESSURE
BUILDING ACROSS NORTHEAST MEXICO AND SOUTHWEST PORTIONS OF DEEP
SOUTH TEXAS. FORECAST SOUNDINGS INDICATE SOME WARMING TAKING PLACE
BETWEEN 850-700MB THIS AFTERNOON AND SOUTHERLY WINDS NOT
CONDUCIVE FOR THE SEA BREEZE TO MAKE HEADWAY TOO FAR WEST. RAP AND
SREF AS WELL AS A CONSALL MODEL BLEND KEEP THE BEST CHANCES ALONG
THE COASTAL COUNTIES WITH KENEDY COUNTY HAVE THE HIGHEST CHANCES.
ADJUSTED CLOUD COVER AS WELL TO ACCOMMODATE WHERE POPS ARE MORE
LIKELY TO DEVELOP. TEMPERATURES LOOK WITHIN THE BALL PARK WITH NO
CHANGES AT THIS TIME. NEW TEMP/POP TABLE BELOW.
PREV DISCUSSION... /ISSUED 606 AM CDT WED SEP 17 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR TAFS NEXT 24 HOURS. RADAR IS QUIETER THIS MORNING
WITH ONLY A FEW MARINE SHOWERS DEPICTED. LOOKING AT JUST A FEW
MID VALLEY LOW CLOUDS FROM OBSERVATIONS AND JUST A FEW HIGH
CLOUDS ON SATELLITE ORIGINATING FROM TROPICAL STORM ODILE IN THE
NORTHERN GULF OF CALIFORNIA. PATCHY LIGHT FOG IN A FEW SPOTS IS
NOT SIGNIFICANT. OTHERWISE...LIGHT SOUTH SOUTHEAST WINDS EXPECTED
TODAY...WITH SCT TO BKN LOW CLOUDS MOSTLY ABOVE 3 KFT BY LATE
MORNING DUE TO AMPLE RESIDUAL LOW LEVEL MOISTURE. MID LEVEL
RIDGING OVERHEAD WILL HELP STABILIZE THE ATMOSPHERE...BUT ISOLD
SHOWERS MAY STILL DEVELOP TODAY...INCLUDING ALONG THE SEA BREEZE.
PREV DISCUSSION... /ISSUED 334 AM CDT WED SEP 17 2014/
SHORT TERM /TODAY THROUGH THURSDAY/...COLUMN MOISTURE WILL REMAIN
ELEVATED ACROSS DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY THROUGH
THE SHORT TERM...WITH PWAT HOVERING AROUND TWO INCHES. MID LEVEL
RIDGING OVERHEAD...SUPPORTING HIGH PRESSURE OVER THE NORTHWEST
GULF...WILL TEND TO STABILIZE WEATHER CONDITIONS HOWEVER...WITH A
SITUATION MORE LIKELY TO SUPPORT A SEA BREEZE RATHER THAN WIDESPREAD
PRECIP. NONETHELESS...A FEW HEAVIER SHOWERS COULD DEVELOP...WHICH
COULD BE OF CONCERN TO AREAS WHICH RECENTLY RECEIVED A LOT OF RAIN.
MID LEVEL RIDGING WILL SLOWLY SUCCEED IN DEVELOPING SOME SUBSIDENCE
AND INHIBITION IN THE SOUNDING...AND FEEL THAT TODAY MIGHT BE BETTER
FOR WESTWARD MVG SEA BREEZE CONVECTION THAN TOMORROW...BUT ANOTHER
SEA BREEZE ROUND WILL STILL BE POSSIBLE ON THURSDAY. SHOULD SEE A
MIX OF CLOUDS AND SUN TODAY WITH NEAR NORMAL TEMPS AND LIGHT TO
MODERATE SOUTH SOUTHEAST WINDS. A FEW HIGH CLOUDS ORIGINATING WITH
ODILE WILL STILL BE IN THE MIX. MID 70S WILL BE ON TAP TONIGHT WITH
A FEW MORE LOW CLDS DUE TO WINDS BACKING A BIT TO A MORE SOUTHEAST
ONSHORE FLOW. LOOK FOR INCREASED LOW CLOUDS THURSDAY DUE TO A WEAK
CAP BUT STILL PARTLY CLOUDY WITH MODERATE SOUTHEAST WINDS. TEMPS
WILL AGAIN BE NEAR NORMAL. MAINTAINED MUCH OF THE INHERITED FORECAST
PACKAGE...BUT TRENDED POPS DOWN JUST A WEE BIT...10 PERCENT HERE AND
THERE...BASED ON MORE STABILITY AND A LESSER SOURCE OF MOISTURE FROM
THE SOUTH. USED A BLEND FOR TEMPS BUT BUMPED UP HIGH TEMPS A DEGREE
FROM THE BLEND BASED ON TUESDAY`S PERFORMANCE AND CHANCE OF SEEING
SOME SUN AGAIN TODAY.
LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THURSDAY NIGHT INTO FRIDAY WE WILL RETAIN RICH COLUMN MOISTURE WITH
850-700MB RH VALUES OVER 70 PERCENT. NORTHWESTERLY 300-500MB FLOW
WILL DEVELOP AS RIDGING DEVELOPS IN THAT LAYER OVER WEST/CENTRAL
TEXAS AND NORTHERN MEXICO. EMBEDDED IN THIS FLOW IS WEAK
PERTURBATIONS AND RESIDUAL MOISTURE FROM THE REMNANTS OF ODILE. LOW
LEVEL FLOW WILL BE MODERATE OUT OF THE SOUTHEAST. KEPT 20 TO 30 PCT
POPS IN THE FORECAST IN THE MORNING HOURS INCREASING TO 40 PCT VALLEY
WIDE IN THE AFTERNOON WITH 50 PCT OVER THE RANCHLANDS WHERE SLIGHTLY
BETTER MID LEVEL ASCENT IS FORECAST TO BE IN PLACE ENHANCING
SEABREEZE CONVERGENCE. PRECIPITABLE WATER VALUES AROUND 2.0 TO 2.2
INCHES WILL POSITION ANY CELL THAT GETS GOING TO BE A VERY HEAVY
RAINFALL PRODUCER...ALTHOUGH STORM MOTION AND COVERAGE SHOULD
PREVENT A WIDESPREAD FLOODING RISK...ASSUMING LIMITED CONVECTIVE
COVERAGE IN THE DAYS LEADING UP TO FRIDAY.
SATURDAY THE GFS DISRUPTS THE EAST TO SOUTHEAST 850 TO 700MB
MOISTURE TAP FROM THE GULF OF MEXICO WHILE THE ECMWF KEEPS ABOUT 10
TO 15 KNOT FLOW GOING. BOTH SEEM TO BE KEYING IN ON WEAK WAVES
DEVELOPED BY CONVECTION OVER BELIZE AND THE YUCATAN. THE ECMWF
APPEARS TO HAVE A BETTER HANDLE BASED ON HOW THESE SYSTEMS HAVE
BEHAVED THIS SEASON AND LEANED THE FORECAST IN THE DIRECTION OF THE
ECMWF...WHICH MATCHES WITH THE EXISTING FORECAST WELL. THIS CALLS
FOR LOW POPS IN THE MORNING PEAKING IN THE AFTERNOON AT 20 TO 30 PCT.
SUNDAY AND MONDAY THE SYNOPTIC PATTERN REMAINS LITTLE CHANGED. MID
LEVEL RIDGING PERSISTS OVER NORTHERN MEXICO AND CENTRAL TEXAS. WE
REMAIN IN MOIST 850-700MB SOUTHEASTERLY TO EASTERLY FLOW WITH NO
REAL DISCERNIBLE WAVES TO ENHANCE SHOWERS/STORMS. WENT WITH POP
PATTERN FAVORING OVERNIGHT SHOWERS ON THE GULF OF MEXICO WORKING
INTO SEABREEZE INITIATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON
WITH 30 PCT POPS IN THE FAVORED ZONES...BASICALLY VALLEY WIDE SUNDAY
AND IN A RAYMONDVILLE/HEBBRONVILLE/FALFURRIAS TRIANGLE ON MONDAY
SURROUNDED BY 20 PCT POPS. THIS IS BELOW GUIDANCE CONSENSUS BUT
PERSISTENT 500MB SUBSIDENCE IN THE VICINITY WILL LIKELY LIMIT MID
LEVEL LAPSE RATES AND INSTABILITY AND ULTIMATELY CONVECTIVE COVERAGE
BY MAKING NEW UPDRAFTS FIGHT A MORE HOSTILE AIRMASS.
TUESDAY THE ECMWF PUSHES A FRONT INTO THE AREA FROM THE NORTHWEST
WHILE THE GFS HOLDS OFF. THE ECMWF IS SLOWER AND MORE AMPLIFIED WITH
RIDGING OVER THE DAKOTAS WHICH ULTIMATELY HELPS PUSH THE FRONT
THROUGH THE AREA. THE GFS BRINGS A JET MAX INTO THE PACIFIC
NORTHWEST FROM NEARLY DUE WEST WHILE THE ECMWF IS MORE AMPLIFIED
WHICH BETTER AGREES WITH THE ONGOING PATTERN OVER THE CENTRAL AND
NORTHWEST CONUS. GFS ENSEMBLE MEMBERS ALSO LEAN IN A SLIGHT MAJORITY
TOWARDS THE MORE NORTHWESTWARD ORIENTED SPEED MAX WHICH LENDS
CREDIBILITY TO THE ECMWF SOLUTION WHICH IS LESS PROGRESSIVE AND
STRONGER WITH RIDGING THAT RESULTS IN THE FRONT PUSHING THROUGH.
INTRODUCED 20/SLIGHT CHANCE POPS ON TUESDAY GIVEN THE PRESENCE OF
THE FRONT. THIS IS BELOW GUIDANCE CONSENSUS BUT RUN TO RUN
CONTINUITY HAS BEEN POOR OVER THE LAST FEW RUNS.
WEDNESDAY THE GFS SENDS A FAIRLY ROBUST COLD FRONT THROUGH THE AREA
WHILE THE ECMWF HOLDS OFF. THE ECMWF IS SLOWER AND LESS AMPLIFIED
WITH A 300MB WEST TEXAS TROUGH WHILE THE GFS SHOWS AN
ANOMALOUSLY STRONG TROUGH WHICH GENERATES A WEST TEXAS SFC CYCLONE
THAT RIDES OVER A STALLED FRONT IN THE AREA PRODUCING WIDESPREAD
RAINFALL. THE ECMWF HOLDS UP BETTER RUN TO RUN AND GIVEN THE ANOMALOUS
STRENGTH OF THE 00Z GFS TROUGH WENT WITH THAT FOR THE FORECAST JUST
HOLDING A SLIGHT CHANCE OF SHOWERS IN THE FORECAST. A SHIFT THOUGH
TOWARDS A FINAL GFS SOLUTION WILL RESULT IN SIGNIFICANT INCREASES IN
RAIN CHANCES BY THE MIDDLE OF NEXT WEEK. /68-JGG/
MARINE...
TODAY THROUGH THURSDAY...BROAD HIGH PRESSURE OVER THE NORTH WEST
GULF WILL SUPPORT LIGHT TO MODERATE SOUTH SOUTHEAST WINDS THROUGH
THE SHORT TERM PERIOD. TWO TO FOUR FEET SEAS WILL PERSIST ON THE
GULF...WITH A LGT TO MODERATE CHOP ON THE BAY. AN ISOLATED MARINE
SHOWER MAY DEVELOP FROM TIME TO TIME.
THURSDAY NIGHT THROUGH MONDAY...
MODERATE EAST TO SOUTHEAST FLOW AND LOW TO MODERATE SEAS ARE
FORECAST THURSDAY NIGHT THROUGH MONDAY ALONG THE LOWER TEXAS COAST.
MORNING SHOWER AND THUNDERSTORM CHANCES WILL PERSIST THROUGH THE DAY
BUT WIDESPREAD SHOWERS AND THUNDERSTORMS ARE NOT CURRENTLY FORECAST.
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW EXERCISE CAUTION LEVELS
FOR THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 90 80 90 79 / 20 20 40 20
BROWNSVILLE 91 78 91 78 / 20 20 40 20
HARLINGEN 92 78 93 77 / 20 20 40 20
MCALLEN 94 78 94 78 / 10 10 30 20
RIO GRANDE CITY 94 77 95 78 / 10 10 20 20
SOUTH PADRE ISLAND 87 81 87 80 / 30 20 30 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
59/58
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1133 AM CDT WED SEP 17 2014
.DISCUSSION...REDUCED POPS FOR THIS AFTERNOON WITH HIGH PRESSURE
BUILDING ACROSS NORTHEAST MEXICO AND SOUTHWEST PORTIONS OF DEEP
SOUTH TEXAS. FORECAST SOUNDINGS INDICATE SOME WARMING TAKING PLACE
BETWEEN 850-700MB THIS AFTERNOON AND SOUTHERLY WINDS NOT
CONDUCIVE FOR THE SEA BREEZE TO MAKE HEADWAY TOO FAR WEST. RAP AND
SREF AS WELL AS A CONSALL MODEL BLEND KEEP THE BEST CHANCES ALONG
THE COASTAL COUNTIES WITH KENEDY COUNTY HAVE THE HIGHEST CHANCES.
ADJUSTED CLOUD COVER AS WELL TO ACCOMMODATE WHERE POPS ARE MORE
LIKELY TO DEVELOP. TEMPERATURES LOOK WITHIN THE BALL PARK WITH NO
CHANGES AT THIS TIME. NEW TEMP/POP TABLE BELOW.
&&
.PREV DISCUSSION... /ISSUED 606 AM CDT WED SEP 17 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR TAFS NEXT 24 HOURS. RADAR IS QUIETER THIS MORNING
WITH ONLY A FEW MARINE SHOWERS DEPICTED. LOOKING AT JUST A FEW
MID VALLEY LOW CLOUDS FROM OBSERVATIONS AND JUST A FEW HIGH
CLOUDS ON SATELLITE ORIGINATING FROM TROPICAL STORM ODILE IN THE
NORTHERN GULF OF CALIFORNIA. PATCHY LIGHT FOG IN A FEW SPOTS IS
NOT SIGNIFICANT. OTHERWISE...LIGHT SOUTH SOUTHEAST WINDS EXPECTED
TODAY...WITH SCT TO BKN LOW CLOUDS MOSTLY ABOVE 3 KFT BY LATE
MORNING DUE TO AMPLE RESIDUAL LOW LEVEL MOISTURE. MID LEVEL
RIDGING OVERHEAD WILL HELP STABILIZE THE ATMOSPHERE...BUT ISOLD
SHOWERS MAY STILL DEVELOP TODAY...INCLUDING ALONG THE SEA BREEZE.
PREV DISCUSSION... /ISSUED 334 AM CDT WED SEP 17 2014/
SHORT TERM /TODAY THROUGH THURSDAY/...COLUMN MOISTURE WILL REMAIN
ELEVATED ACROSS DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY THROUGH
THE SHORT TERM...WITH PWAT HOVERING AROUND TWO INCHES. MID LEVEL
RIDGING OVERHEAD...SUPPORTING HIGH PRESSURE OVER THE NORTHWEST
GULF...WILL TEND TO STABILIZE WEATHER CONDITIONS HOWEVER...WITH A
SITUATION MORE LIKELY TO SUPPORT A SEA BREEZE RATHER THAN WIDESPREAD
PRECIP. NONETHELESS...A FEW HEAVIER SHOWERS COULD DEVELOP...WHICH
COULD BE OF CONCERN TO AREAS WHICH RECENTLY RECEIVED A LOT OF RAIN.
MID LEVEL RIDGING WILL SLOWLY SUCCEED IN DEVELOPING SOME SUBSIDENCE
AND INHIBITION IN THE SOUNDING...AND FEEL THAT TODAY MIGHT BE BETTER
FOR WESTWARD MVG SEA BREEZE CONVECTION THAN TOMORROW...BUT ANOTHER
SEA BREEZE ROUND WILL STILL BE POSSIBLE ON THURSDAY. SHOULD SEE A
MIX OF CLOUDS AND SUN TODAY WITH NEAR NORMAL TEMPS AND LIGHT TO
MODERATE SOUTH SOUTHEAST WINDS. A FEW HIGH CLOUDS ORIGINATING WITH
ODILE WILL STILL BE IN THE MIX. MID 70S WILL BE ON TAP TONIGHT WITH
A FEW MORE LOW CLDS DUE TO WINDS BACKING A BIT TO A MORE SOUTHEAST
ONSHORE FLOW. LOOK FOR INCREASED LOW CLOUDS THURSDAY DUE TO A WEAK
CAP BUT STILL PARTLY CLOUDY WITH MODERATE SOUTHEAST WINDS. TEMPS
WILL AGAIN BE NEAR NORMAL. MAINTAINED MUCH OF THE INHERITED FORECAST
PACKAGE...BUT TRENDED POPS DOWN JUST A WEE BIT...10 PERCENT HERE AND
THERE...BASED ON MORE STABILITY AND A LESSER SOURCE OF MOISTURE FROM
THE SOUTH. USED A BLEND FOR TEMPS BUT BUMPED UP HIGH TEMPS A DEGREE
FROM THE BLEND BASED ON TUESDAY`S PERFORMANCE AND CHANCE OF SEEING
SOME SUN AGAIN TODAY.
LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THURSDAY NIGHT INTO FRIDAY WE WILL RETAIN RICH COLUMN MOISTURE WITH
850-700MB RH VALUES OVER 70 PERCENT. NORTHWESTERLY 300-500MB FLOW
WILL DEVELOP AS RIDGING DEVELOPS IN THAT LAYER OVER WEST/CENTRAL
TEXAS AND NORTHERN MEXICO. EMBEDDED IN THIS FLOW IS WEAK
PERTURBATIONS AND RESIDUAL MOISTURE FROM THE REMNANTS OF ODILE. LOW
LEVEL FLOW WILL BE MODERATE OUT OF THE SOUTHEAST. KEPT 20 TO 30 PCT
POPS IN THE FORECAST IN THE MORNING HOURS INCREASING TO 40 PCT VALLEY
WIDE IN THE AFTERNOON WITH 50 PCT OVER THE RANCHLANDS WHERE SLIGHTLY
BETTER MID LEVEL ASCENT IS FORECAST TO BE IN PLACE ENHANCING
SEABREEZE CONVERGENCE. PRECIPITABLE WATER VALUES AROUND 2.0 TO 2.2
INCHES WILL POSITION ANY CELL THAT GETS GOING TO BE A VERY HEAVY
RAINFALL PRODUCER...ALTHOUGH STORM MOTION AND COVERAGE SHOULD
PREVENT A WIDESPREAD FLOODING RISK...ASSUMING LIMITED CONVECTIVE
COVERAGE IN THE DAYS LEADING UP TO FRIDAY.
SATURDAY THE GFS DISRUPTS THE EAST TO SOUTHEAST 850 TO 700MB
MOISTURE TAP FROM THE GULF OF MEXICO WHILE THE ECMWF KEEPS ABOUT 10
TO 15 KNOT FLOW GOING. BOTH SEEM TO BE KEYING IN ON WEAK WAVES
DEVELOPED BY CONVECTION OVER BELIZE AND THE YUCATAN. THE ECMWF
APPEARS TO HAVE A BETTER HANDLE BASED ON HOW THESE SYSTEMS HAVE
BEHAVED THIS SEASON AND LEANED THE FORECAST IN THE DIRECTION OF THE
ECMWF...WHICH MATCHES WITH THE EXISTING FORECAST WELL. THIS CALLS
FOR LOW POPS IN THE MORNING PEAKING IN THE AFTERNOON AT 20 TO 30 PCT.
SUNDAY AND MONDAY THE SYNOPTIC PATTERN REMAINS LITTLE CHANGED. MID
LEVEL RIDGING PERSISTS OVER NORTHERN MEXICO AND CENTRAL TEXAS. WE
REMAIN IN MOIST 850-700MB SOUTHEASTERLY TO EASTERLY FLOW WITH NO
REAL DISCERNIBLE WAVES TO ENHANCE SHOWERS/STORMS. WENT WITH POP
PATTERN FAVORING OVERNIGHT SHOWERS ON THE GULF OF MEXICO WORKING
INTO SEABREEZE INITIATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON
WITH 30 PCT POPS IN THE FAVORED ZONES...BASICALLY VALLEY WIDE SUNDAY
AND IN A RAYMONDVILLE/HEBBRONVILLE/FALFURRIAS TRIANGLE ON MONDAY
SURROUNDED BY 20 PCT POPS. THIS IS BELOW GUIDANCE CONSENSUS BUT
PERSISTENT 500MB SUBSIDENCE IN THE VICINITY WILL LIKELY LIMIT MID
LEVEL LAPSE RATES AND INSTABILITY AND ULTIMATELY CONVECTIVE COVERAGE
BY MAKING NEW UPDRAFTS FIGHT A MORE HOSTILE AIRMASS.
TUESDAY THE ECMWF PUSHES A FRONT INTO THE AREA FROM THE NORTHWEST
WHILE THE GFS HOLDS OFF. THE ECMWF IS SLOWER AND MORE AMPLIFIED WITH
RIDGING OVER THE DAKOTAS WHICH ULTIMATELY HELPS PUSH THE FRONT
THROUGH THE AREA. THE GFS BRINGS A JET MAX INTO THE PACIFIC
NORTHWEST FROM NEARLY DUE WEST WHILE THE ECMWF IS MORE AMPLIFIED
WHICH BETTER AGREES WITH THE ONGOING PATTERN OVER THE CENTRAL AND
NORTHWEST CONUS. GFS ENSEMBLE MEMBERS ALSO LEAN IN A SLIGHT MAJORITY
TOWARDS THE MORE NORTHWESTWARD ORIENTED SPEED MAX WHICH LENDS
CREDIBILITY TO THE ECMWF SOLUTION WHICH IS LESS PROGRESSIVE AND
STRONGER WITH RIDGING THAT RESULTS IN THE FRONT PUSHING THROUGH.
INTRODUCED 20/SLIGHT CHANCE POPS ON TUESDAY GIVEN THE PRESENCE OF
THE FRONT. THIS IS BELOW GUIDANCE CONSENSUS BUT RUN TO RUN
CONTINUITY HAS BEEN POOR OVER THE LAST FEW RUNS.
WEDNESDAY THE GFS SENDS A FAIRLY ROBUST COLD FRONT THROUGH THE AREA
WHILE THE ECMWF HOLDS OFF. THE ECMWF IS SLOWER AND LESS AMPLIFIED
WITH A 300MB WEST TEXAS TROUGH WHILE THE GFS SHOWS AN
ANOMALOUSLY STRONG TROUGH WHICH GENERATES A WEST TEXAS SFC CYCLONE
THAT RIDES OVER A STALLED FRONT IN THE AREA PRODUCING WIDESPREAD
RAINFALL. THE ECMWF HOLDS UP BETTER RUN TO RUN AND GIVEN THE ANOMALOUS
STRENGTH OF THE 00Z GFS TROUGH WENT WITH THAT FOR THE FORECAST JUST
HOLDING A SLIGHT CHANCE OF SHOWERS IN THE FORECAST. A SHIFT THOUGH
TOWARDS A FINAL GFS SOLUTION WILL RESULT IN SIGNIFICANT INCREASES IN
RAIN CHANCES BY THE MIDDLE OF NEXT WEEK. /68-JGG/
MARINE...
TODAY THROUGH THURSDAY...BROAD HIGH PRESSURE OVER THE NORTH WEST
GULF WILL SUPPORT LIGHT TO MODERATE SOUTH SOUTHEAST WINDS THROUGH
THE SHORT TERM PERIOD. TWO TO FOUR FEET SEAS WILL PERSIST ON THE
GULF...WITH A LGT TO MODERATE CHOP ON THE BAY. AN ISOLATED MARINE
SHOWER MAY DEVELOP FROM TIME TO TIME.
THURSDAY NIGHT THROUGH MONDAY...
MODERATE EAST TO SOUTHEAST FLOW AND LOW TO MODERATE SEAS ARE
FORECAST THURSDAY NIGHT THROUGH MONDAY ALONG THE LOWER TEXAS COAST.
MORNING SHOWER AND THUNDERSTORM CHANCES WILL PERSIST THROUGH THE DAY
BUT WIDESPREAD SHOWERS AND THUNDERSTORMS ARE NOT CURRENTLY FORECAST.
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW EXERCISE CAUTION LEVELS
FOR THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 90 80 90 79 / 20 20 40 20
BROWNSVILLE 91 78 91 78 / 20 20 40 20
HARLINGEN 92 78 93 77 / 20 20 40 20
MCALLEN 94 78 94 78 / 10 10 30 20
RIO GRANDE CITY 94 77 95 78 / 10 10 20 20
SOUTH PADRE ISLAND 87 81 87 80 / 30 20 30 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
59...SHORT TERM
58...LONG TERM
CAMPBELL...GRAPHICS
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
233 AM PDT THU SEP 18 2014
.SYNOPSIS...
A weak cold front will move through Washington and Idaho today.
The front will push temperatures closer to normal and bring the
potential for widely scattered showers. A strong high pressure
ridge will return Friday and promote warm and dry weather through
the weekend. High temperatures Sunday should be ten degrees above
normal. The breakdown of this ridge...and a return to cooler
conditions...will begin Monday. However...precipitation is not
expected until late Tuesday or Wednesday for most towns.
&&
.DISCUSSION...
Today and Tonight...Scattered showers will develop across the
Inland Northwest today as moisture continues to stream into the
region from the southwest. So far the light radar returns on
regional radar mosaic have not resulted in any precipitation
reports from observation sites across the forecast area. The dry
lower levels of the atmosphere, as seen on 00Z OTX sounding, will
take a while to moisten up. The best chance of showers across the
area will be this afternoon as the cold front and shortwave trough
slide across the region. Modest instability may allow isolated
thunderstorms to develop across extreme eastern WA and the
panhandle of Idaho. As daytime instability increases this
afternoon, bulk shear decreases substantially so organized storm
cells are not anticipated. Winds will increase behind the cold
front, with gusts of 25 to 30 mph common from the Cascade gap
valleys, across the basin and into the Palouse and west plains.
Daytime temperatures will be somewhat cooler for the western zones
but pretty close to Wednesday`s readings for extreme eastern WA
and north Idaho. Overnight temperatures tonight will remain above
normal thanks to gusty winds behind the front. /Kelch
Fri through Mon Nt: With a rapidly building upper ridge Fri
through the weekend, we`re not expecting any pcpn as large-scale
subsidence/warming aloft accompanies clear skies and light winds.
Fri morning should be the coolest morning, with some NE Wa and N
Idaho valleys seeing some patchy fog. The warmest day should be
Sunday with high temps generally in the 80s... 10 degrees warmer
than normal for a number of towns. The breakdown of the
ridge...and the approach of a strong Ern Pacific trough...still
looks to be on track for the Mon through Tue time frame. Based on
trends in model guidance, the lack of sufficient instability, and
a deep sub-cloud dry lyr, the first minor wave that ejects from
the offshore trough Tues morning is not expected to produce any
pcpn outside of the mtns across the E Slopes of the Cascades.bz
Tuesday through Thursday: A cold front will be pushing through the
region during this period bringing a small taste of autumn along
with it. Poor consistency among the models is keeping the exact
timing of the front a little unclear. It is expected to a chance
of precip to the entire Inland Northwest and temperatures will
decrease around 10 degrees from the beginning of the period. /JDC
&&
.AVIATION...
06Z TAFS: A moist southwest flow and incoming cold front/upper
trough impact the Inland NW, providing 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. A threat will come up
through the Blue Mountain and toward the Central Panhandle of ID
late overnight into Thursday morning, potentially near LWS and PUW
between 09-15Z. Other chances will be found in the vcnty of GEG to
COE in the afternoon with the passing front. There is also the
slight risk for -tsra across the MTNS of far eastern WA and north
ID. Expect increased winds Thursday afternoon, with gusts in the
20 to 25kt range, locally higher near EAT. Winds will gradually
abate after Thursday evening (after 02-04Z). /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 80 55 76 48 81 52 / 20 10 0 0 0 0
Coeur d`Alene 79 54 76 46 80 49 / 30 20 10 0 0 0
Pullman 81 53 76 45 81 49 / 20 10 0 0 0 0
Lewiston 86 60 82 53 86 55 / 20 10 0 0 0 0
Colville 83 52 80 45 84 47 / 40 20 10 0 0 0
Sandpoint 75 47 74 39 78 44 / 40 30 10 10 0 0
Kellogg 77 53 73 46 78 46 / 30 20 10 0 0 0
Moses Lake 85 57 84 49 85 53 / 10 0 0 0 0 0
Wenatchee 82 61 83 54 84 55 / 20 10 0 0 0 0
Omak 82 55 82 48 85 49 / 30 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
233 AM PDT THU SEP 18 2014
.SYNOPSIS...
A weak cold front will move through Washington and Idaho today.
The front will push temperatures closer to normal and bring the
potential for widely scattered showers. A strong high pressure
ridge will return Friday and promote warm and dry weather through
the weekend. High temperatures Sunday should be ten degrees above
normal. The breakdown of this ridge...and a return to cooler
conditions...will begin Monday. However...precipitation is not
expected until late Tuesday or Wednesday for most towns.
&&
.DISCUSSION...
Today and Tonight...Scattered showers will develop across the
Inland Northwest today as moisture continues to stream into the
region from the southwest. So far the light radar returns on
regional radar mosaic have not resulted in any precipitation
reports from observation sites across the forecast area. The dry
lower levels of the atmosphere, as seen on 00Z OTX sounding, will
take a while to moisten up. The best chance of showers across the
area will be this afternoon as the cold front and shortwave trough
slide across the region. Modest instability may allow isolated
thunderstorms to develop across extreme eastern WA and the
panhandle of Idaho. As daytime instability increases this
afternoon, bulk shear decreases substantially so organized storm
cells are not anticipated. Winds will increase behind the cold
front, with gusts of 25 to 30 mph common from the Cascade gap
valleys, across the basin and into the Palouse and west plains.
Daytime temperatures will be somewhat cooler for the western zones
but pretty close to Wednesday`s readings for extreme eastern WA
and north Idaho. Overnight temperatures tonight will remain above
normal thanks to gusty winds behind the front. /Kelch
Fri through Mon Nt: With a rapidly building upper ridge Fri
through the weekend, we`re not expecting any pcpn as large-scale
subsidence/warming aloft accompanies clear skies and light winds.
Fri morning should be the coolest morning, with some NE Wa and N
Idaho valleys seeing some patchy fog. The warmest day should be
Sunday with high temps generally in the 80s... 10 degrees warmer
than normal for a number of towns. The breakdown of the
ridge...and the approach of a strong Ern Pacific trough...still
looks to be on track for the Mon through Tue time frame. Based on
trends in model guidance, the lack of sufficient instability, and
a deep sub-cloud dry lyr, the first minor wave that ejects from
the offshore trough Tues morning is not expected to produce any
pcpn outside of the mtns across the E Slopes of the Cascades.bz
Tuesday through Thursday: A cold front will be pushing through the
region during this period bringing a small taste of autumn along
with it. Poor consistency among the models is keeping the exact
timing of the front a little unclear. It is expected to a chance
of precip to the entire Inland Northwest and temperatures will
decrease around 10 degrees from the beginning of the period. /JDC
&&
.AVIATION...
06Z TAFS: A moist southwest flow and incoming cold front/upper
trough impact the Inland NW, providing 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. A threat will come up
through the Blue Mountain and toward the Central Panhandle of ID
late overnight into Thursday morning, potentially near LWS and PUW
between 09-15Z. Other chances will be found in the vcnty of GEG to
COE in the afternoon with the passing front. There is also the
slight risk for -tsra across the MTNS of far eastern WA and north
ID. Expect increased winds Thursday afternoon, with gusts in the
20 to 25kt range, locally higher near EAT. Winds will gradually
abate after Thursday evening (after 02-04Z). /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 80 55 76 48 81 52 / 20 10 0 0 0 0
Coeur d`Alene 79 54 76 46 80 49 / 30 20 10 0 0 0
Pullman 81 53 76 45 81 49 / 20 10 0 0 0 0
Lewiston 86 60 82 53 86 55 / 20 10 0 0 0 0
Colville 83 52 80 45 84 47 / 40 20 10 0 0 0
Sandpoint 75 47 74 39 78 44 / 40 30 10 10 0 0
Kellogg 77 53 73 46 78 46 / 30 20 10 0 0 0
Moses Lake 85 57 84 49 85 53 / 10 0 0 0 0 0
Wenatchee 82 61 83 54 84 55 / 20 10 0 0 0 0
Omak 82 55 82 48 85 49 / 30 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
233 AM PDT THU SEP 18 2014
.SYNOPSIS...
A weak cold front will move through Washington and Idaho today.
The front will push temperatures closer to normal and bring the
potential for widely scattered showers. A strong high pressure
ridge will return Friday and promote warm and dry weather through
the weekend. High temperatures Sunday should be ten degrees above
normal. The breakdown of this ridge...and a return to cooler
conditions...will begin Monday. However...precipitation is not
expected until late Tuesday or Wednesday for most towns.
&&
.DISCUSSION...
Today and Tonight...Scattered showers will develop across the
Inland Northwest today as moisture continues to stream into the
region from the southwest. So far the light radar returns on
regional radar mosaic have not resulted in any precipitation
reports from observation sites across the forecast area. The dry
lower levels of the atmosphere, as seen on 00Z OTX sounding, will
take a while to moisten up. The best chance of showers across the
area will be this afternoon as the cold front and shortwave trough
slide across the region. Modest instability may allow isolated
thunderstorms to develop across extreme eastern WA and the
panhandle of Idaho. As daytime instability increases this
afternoon, bulk shear decreases substantially so organized storm
cells are not anticipated. Winds will increase behind the cold
front, with gusts of 25 to 30 mph common from the Cascade gap
valleys, across the basin and into the Palouse and west plains.
Daytime temperatures will be somewhat cooler for the western zones
but pretty close to Wednesday`s readings for extreme eastern WA
and north Idaho. Overnight temperatures tonight will remain above
normal thanks to gusty winds behind the front. /Kelch
Fri through Mon Nt: With a rapidly building upper ridge Fri
through the weekend, we`re not expecting any pcpn as large-scale
subsidence/warming aloft accompanies clear skies and light winds.
Fri morning should be the coolest morning, with some NE Wa and N
Idaho valleys seeing some patchy fog. The warmest day should be
Sunday with high temps generally in the 80s... 10 degrees warmer
than normal for a number of towns. The breakdown of the
ridge...and the approach of a strong Ern Pacific trough...still
looks to be on track for the Mon through Tue time frame. Based on
trends in model guidance, the lack of sufficient instability, and
a deep sub-cloud dry lyr, the first minor wave that ejects from
the offshore trough Tues morning is not expected to produce any
pcpn outside of the mtns across the E Slopes of the Cascades.bz
Tuesday through Thursday: A cold front will be pushing through the
region during this period bringing a small taste of autumn along
with it. Poor consistency among the models is keeping the exact
timing of the front a little unclear. It is expected to a chance
of precip to the entire Inland Northwest and temperatures will
decrease around 10 degrees from the beginning of the period. /JDC
&&
.AVIATION...
06Z TAFS: A moist southwest flow and incoming cold front/upper
trough impact the Inland NW, providing 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. A threat will come up
through the Blue Mountain and toward the Central Panhandle of ID
late overnight into Thursday morning, potentially near LWS and PUW
between 09-15Z. Other chances will be found in the vcnty of GEG to
COE in the afternoon with the passing front. There is also the
slight risk for -tsra across the MTNS of far eastern WA and north
ID. Expect increased winds Thursday afternoon, with gusts in the
20 to 25kt range, locally higher near EAT. Winds will gradually
abate after Thursday evening (after 02-04Z). /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 80 55 76 48 81 52 / 20 10 0 0 0 0
Coeur d`Alene 79 54 76 46 80 49 / 30 20 10 0 0 0
Pullman 81 53 76 45 81 49 / 20 10 0 0 0 0
Lewiston 86 60 82 53 86 55 / 20 10 0 0 0 0
Colville 83 52 80 45 84 47 / 40 20 10 0 0 0
Sandpoint 75 47 74 39 78 44 / 40 30 10 10 0 0
Kellogg 77 53 73 46 78 46 / 30 20 10 0 0 0
Moses Lake 85 57 84 49 85 53 / 10 0 0 0 0 0
Wenatchee 82 61 83 54 84 55 / 20 10 0 0 0 0
Omak 82 55 82 48 85 49 / 30 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
233 AM PDT THU SEP 18 2014
.SYNOPSIS...
A weak cold front will move through Washington and Idaho today.
The front will push temperatures closer to normal and bring the
potential for widely scattered showers. A strong high pressure
ridge will return Friday and promote warm and dry weather through
the weekend. High temperatures Sunday should be ten degrees above
normal. The breakdown of this ridge...and a return to cooler
conditions...will begin Monday. However...precipitation is not
expected until late Tuesday or Wednesday for most towns.
&&
.DISCUSSION...
Today and Tonight...Scattered showers will develop across the
Inland Northwest today as moisture continues to stream into the
region from the southwest. So far the light radar returns on
regional radar mosaic have not resulted in any precipitation
reports from observation sites across the forecast area. The dry
lower levels of the atmosphere, as seen on 00Z OTX sounding, will
take a while to moisten up. The best chance of showers across the
area will be this afternoon as the cold front and shortwave trough
slide across the region. Modest instability may allow isolated
thunderstorms to develop across extreme eastern WA and the
panhandle of Idaho. As daytime instability increases this
afternoon, bulk shear decreases substantially so organized storm
cells are not anticipated. Winds will increase behind the cold
front, with gusts of 25 to 30 mph common from the Cascade gap
valleys, across the basin and into the Palouse and west plains.
Daytime temperatures will be somewhat cooler for the western zones
but pretty close to Wednesday`s readings for extreme eastern WA
and north Idaho. Overnight temperatures tonight will remain above
normal thanks to gusty winds behind the front. /Kelch
Fri through Mon Nt: With a rapidly building upper ridge Fri
through the weekend, we`re not expecting any pcpn as large-scale
subsidence/warming aloft accompanies clear skies and light winds.
Fri morning should be the coolest morning, with some NE Wa and N
Idaho valleys seeing some patchy fog. The warmest day should be
Sunday with high temps generally in the 80s... 10 degrees warmer
than normal for a number of towns. The breakdown of the
ridge...and the approach of a strong Ern Pacific trough...still
looks to be on track for the Mon through Tue time frame. Based on
trends in model guidance, the lack of sufficient instability, and
a deep sub-cloud dry lyr, the first minor wave that ejects from
the offshore trough Tues morning is not expected to produce any
pcpn outside of the mtns across the E Slopes of the Cascades.bz
Tuesday through Thursday: A cold front will be pushing through the
region during this period bringing a small taste of autumn along
with it. Poor consistency among the models is keeping the exact
timing of the front a little unclear. It is expected to a chance
of precip to the entire Inland Northwest and temperatures will
decrease around 10 degrees from the beginning of the period. /JDC
&&
.AVIATION...
06Z TAFS: A moist southwest flow and incoming cold front/upper
trough impact the Inland NW, providing 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. A threat will come up
through the Blue Mountain and toward the Central Panhandle of ID
late overnight into Thursday morning, potentially near LWS and PUW
between 09-15Z. Other chances will be found in the vcnty of GEG to
COE in the afternoon with the passing front. There is also the
slight risk for -tsra across the MTNS of far eastern WA and north
ID. Expect increased winds Thursday afternoon, with gusts in the
20 to 25kt range, locally higher near EAT. Winds will gradually
abate after Thursday evening (after 02-04Z). /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 80 55 76 48 81 52 / 20 10 0 0 0 0
Coeur d`Alene 79 54 76 46 80 49 / 30 20 10 0 0 0
Pullman 81 53 76 45 81 49 / 20 10 0 0 0 0
Lewiston 86 60 82 53 86 55 / 20 10 0 0 0 0
Colville 83 52 80 45 84 47 / 40 20 10 0 0 0
Sandpoint 75 47 74 39 78 44 / 40 30 10 10 0 0
Kellogg 77 53 73 46 78 46 / 30 20 10 0 0 0
Moses Lake 85 57 84 49 85 53 / 10 0 0 0 0 0
Wenatchee 82 61 83 54 84 55 / 20 10 0 0 0 0
Omak 82 55 82 48 85 49 / 30 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1032 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...
06Z TAFS: A moist southwest flow and incoming cold front/upper
trough impact the Inland NW, providing 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. A threat will come up
through the Blue Mountain and toward the Central Panhandle of ID
late overnight into Thursday morning, potentially near LWS and PUW
between 09-15Z. Other chances will be found in the vcnty of GEG to
COE in the afternoon with the passing front. There is also the
slight risk for -tsra across the MTNS of far eastern WA and north
ID. Expect increased winds Thursday afternoon, with gusts in the
20 to 25kt range, locally higher near EAT. Winds will gradually
abate after Thursday evening (after 02-04Z). /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
1030 PM CDT THU SEP 18 2014
UPDATED AVIATION PORTION FOR 06Z TAF 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 06Z TAF ISSUANCE
ISSUED AT 1029 PM CDT THU SEP 18 2014
OVERALL VFR CONDITIONS EXPECTED OVERNIGHT INTO FRIDAY
OVER MOST PLACES. HOWEVER PATCHES OF IFR/MVFR CIGS AND VSBYS WITH
FOG MAY DEVELOP OVERNIGHT. LLWS CONDITIONS MAY DEVELOP OVER THE
WEST HALF OF THE STATE LATE TONIGHT FOLLOWED WITH GUSTY SOUTH
WINDS OVER MOST LOCATIONS STARTING LATE FRIDAY MORNING AND
CONTINUE INTO THE AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
704 PM CDT THU SEP 18 2014
UPDATED AVIATION PORTION FOR 00Z TAF 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 00Z TAF ISSUANCE
ISSUED AT 704 PM CDT THU SEP 18 2014
OVERALL VFR CONDITIONS EXPECTED OVERNIGHT INTO FRIDAY OVER
MOST PLACES. HOWEVER PATCHES OF MVFR CIGS AND VSYBS WITH FOG WILL
LINGER OVER EASTERN WISCONSIN THIS EVENING AND PATCHY IFR CIGS AND
VSBYS MAY DEVELOP OVER NORTH CENTRAL WISCONSIN OVERNIGHT. LLWS
CONDITIONS MAY DEVELOP OVER THE WEST HALF OF THE STATE LATE
TONIGHT FOLLOWED WITH GUSTY SOUTH WINDS OVER MOST LOCATIONS
STARTING LATE FRIDAY MORNING ND CONTINUE INTO THE AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......TDH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE
TROUGH MOVING SOUTHEAST OVER THE UPPER PENINSULA AND A STRONG COLD
FRONT DROPPING SOUTH OVER THE UPPER PENINSULA OF MICHIGAN.
SCATTERED SHOWERS OVER LAKE SUPERIOR ARE EXITING THE REGION AHEAD OF
THE SHORTWAVE. BUT THERE IS A FAIRLY WIDESPREAD AREA OF LOW STRATUS
BEHIND THE FRONT...THOUGH STARTING TO SEE SOME BREAKS IN THE
OVERCAST OCCUR OVER NORTHERN MINNESOTA AND LAKE SUPERIOR. NORTHEAST
WINDS ARE ALSO QUITE GUSTY RIGHT BEHIND THE FRONT COINCIDENT WITH
MODEST PRESSURE RISES...AND SOME GUSTS ARE REACHING 30 KTS OVER
SOUTHERN LAKE SUPERIOR. A CANADIAN SURFACE HIGH IS BUILDING
SOUTHEAST BEHIND THE FRONT AND USHERING IN ANOTHER COLD POLAR
AIRMASS WITH SOME SNOW BEING REPORTED JUST NORTH OF LAKE SUPERIOR.
AS THE FRONT DROPS SOUTH...SMALL PRECIP CHANCES...FROST/FREEZE
HEADLINES...AND WIND GUSTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE BACKDOOR COLD FRONT WILL CONTINUE TO SLIDE SOUTH
ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING
HOURS...BEFORE SETTLING OVER SOUTHERN WISCONSIN OVERNIGHT.
MID-LEVEL MOISTURE WILL BE EXITING WITH THE SHORTWAVE THIS
AFTERNOON...SO NOT ANTICIPATING ANY SHOWERS WITH THE FRONT. BUT DO
EXPECT A BAND OF LOW CLOUDS TO ACCOMPANY THE FRONT...ALONG WITH A
WIND SHIFT TO THE NORTHEAST. WITH THE WIND SHIFT...WINDS COULD
BECOME QUITE GUSTY OVER NORTHEAST WISCONSIN...AS TRAJECTORIES WILL
BE FAVORABLE FOR FUNNELING DOWN THE BAY OF GREEN BAY. SOME GUSTS TO
30 MPH ARE POSSIBLE. SOME LOW STRATUS WILL LIKELY LINGER OVER
CENTRAL AND EAST-CENTRAL WISCONSIN THROUGH THE NIGHT...BUT
SUBSIDENCE WILL LIKELY LEAD TO CLEARING OVER N-C WISCONSIN
OVERNIGHT. AS WINDS DIMINISH...THE LEADING GUIDANCE SHOWS LOW TEMPS
FALLING INTO THE UPPER 20S TO MID 30S OVER N-C WISCONSIN. WILL
HOIST A FROST ADVISORY FOR THAT REGION. GREATER CLOUD COVER AND
WIND SPEEDS SHOULD KEEP AREAS SAFE FROM THE FROST FURTHER SOUTH AND
EAST.
THURSDAY...PLENTY OF LOW LEVEL MOISTURE WILL LINGER BEHIND THE FRONT
OVER CENTRAL AND EAST-CENTRAL WISCONSIN IN THE MORNING...WHICH WILL
GRADUALLY RETURN NORTHWARD DURING THE AFTERNOON.
THEREFORE...ANTICIPATE SCT TO BKN CLOUDS TO EXPAND WITH HEATING OF
THE DAY. WITH THE CLOUD COVER AND SHALLOW COLD AIRMASS...HIGHS WILL
RANGE FROM THE MIDDLE 50S TO LOWER 60S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 256 PM CDT WED SEP 17 2014
ZONAL FLOW OVER THE NORTHERN CONUS LATE THIS WEEK WILL QUICKLY
TRANSITION TO MORE HIGHLY AMPLIFIED PATTERN...CHARACTERIZED BY DEEP
TROUGH OVER THE GREAT LAKES AND RIDGE OVER WESTERN CANADA...BY EARLY
NEXT WEEK. FORECAST CHALLENGE EARLY IN THE EXTENDED WILL BE CENTERED
AROUND TIMING AND INTENSITY OF INITIAL SHORTWAVE IMPULSES EMBEDDED
WITHIN ZONAL FLOW FRIDAY INTO SATURDAY. THEREAFTER GREAT LAKES
WILL BE DOMINATED NORTHWESTERLY UPPER-LEVEL FLOW AND BROAD HIGH
PRESSURE DURING THE FIRST HALF OF NEXT WEEK. BEST OPPORTUNITY FOR
SUBSTANTIAL RAINFALL WILL BE EARLY IN THE PERIOD FOLLOWED BY
MAINLY DRY CONDITIONS AT LEAST THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL START OUT ABOVE NORMAL FRIDAY AND SATURDAY...THEN
FALL BACK TO WELL BELOW NORMAL TOWARD THE MIDDLE PART OF NEXT
WEEK...WITH CHILLY NIGHTS AND POTENTIAL FOR AREAS OF FROST ACROSS
PARTS OF CENTRAL AND NORTHERN WISCONSIN.
INITIAL FORECAST CHALLENGE WILL BE TIMING OF SHOWER AND SCATTERED
THUNDERSTORMS ACTIVITY FRIDAY AFTERNOON AND EVENING WITH
APPROACHING SHORTWAVE IMPULSE...IN CONCERT WITH INCREASING LOW-
LEVEL WAA IN WAKE OF DEPARTING HIGH PRESSURE. WARM ADVECTION
BECOMES QUITE ROBUST BY 00Z SATURDAY AS 850 MB SOUTHWESTERLY WINDS
APPROACH 40 KTS. APPEARS MAJORITY OF LATEST MODEL GUIDANCE ARE A
BIT SLOWER ON INITIAL SHORTWAVE IMPULSE THUS HAVE TRIMMED BACK POPS
ACROSS THE EASTERN HALF OF THE FORECAST AREA IN THE 12Z TO 18Z
TIME FRAME FOR FRIDAY. APPEARS BEST FORCING WILL BE OVER NORTHERN
PORTION OF THE FORECAST AREA LATE FRIDAY AFTERNOON INTO FRIDAY
AND HAVE ADJUSTED POPS ACCORDINGLY. ON FRIDAY NIGHT...THE FORECAST
AREA SHOULD BE BECOME INCREASINGLY UNDER THE INFLUENCE OF THE RRQ
OF AN UPPER LEVEL JET THUS EXPECT GENERAL INCREASE IN ORGANIZED SCALE
SYNOPTIC SCALE LIFT AND DESTABILIZATION AHEAD OF SURFACE COLD
FRONT MOVING INTO CENTRAL MINNESOTA BY 06Z. ALTHOUGH STILL MODEL
DIFFERENCES IN LOCATION OF HEAVIEST QPF OVERNIGHT...ALL GUIDANCE
SUGGEST AN OVERALL INCREASE IN COVERAGE OF SHOWER AND THUNDERSTORM
ACTIVITY.
SATURDAY A BIT MORE UNCERTAIN AS STILL A FAIR AMOUNT OF MODEL
SPREAD ON TIMING OF COLD FRONT ACROSS THE FORECAST AREA. ECMWF
FASTER THAN MOST OF THE OTHER GUIDANCE. OPTED TO LEAN MORE TOWARD
A BLEND OF THE SREF MEAN AND ECMWF WHICH SUGGEST A SOMEWHAT FASTER
PROGRESSION. ADJUSTED POPS ACCORDINGLY WITH LIKELY POPS IN THE
MORNING AND TAPERED TOWARD CHANCE DURING THE AFTERNOON. GIVEN
THIS SCENARIO APPEARS ANY DEEP CONVECTION THAT CAN DEVELOP ALONG
THE COLD FRONT DURING THE AFTERNOON WILL MOST LIKELY OCCUR OVER
THE SOUTHEAST HALF OF THE STATE. IF ECMWF IS CORRECT...SATURDAY
AFTERNOON COULD BE MAINLY DRY. IF ENOUGH CLEARING CAN OCCUR
DAYTIME TEMPS SHOULD BE ABLE TO RESPOND AND RISE WELL INTO THE 70S
AS 850 TEMPS REALLY DO NOT FALL MUCH BEHIND THE COLD FRONT
INITIALLY.
ON SATURDAY NIGHT PRONOUNCED LFQ OF UPPER JET THEN PUSHES INTO
THE AREA WITH PRIMARY SHORTWAVE TROUGH CONTINUING TO DEEPEN OVER
THE AREA. WOULD EXPECT TO SEE SHOWER ACTIVITY INCREASE OVERNIGHT
SATURDAY ESPECIALLY ACROSS THE NORTH. UPPER TROUGH AXIS WILL
PERSIST OVER THE AREA ON SUNDAY WITH CAA CONTINUING. SCENARIO
FAVORABLE FOR AFTERNOON DIURNAL SHOWER ACTIVITY TO DEVELOP OVER
THE NORTHERN PORTION OF THE FORECAST AREA. LEFT SMALL POPS IN FOR
SUNDAY TO ACCOUNT FOR THIS.
HIGH PRESSURE FINALLY BUILDS IN SUNDAY NIGHT AND MONDAY BRINGING A
STRETCH OF DRIER WEATHER INTO AT LEAST MIDWEEK. EXPECT TEMPS TO BE
BELOW NORMAL THROUGH THE FIRST HALF OF THE WEEK WITH POTENTIAL FOR
SOME EARLY MORNING FROST OR FREEZE ESPECIALLY ON TUESDAY MORNING.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1133 AM CDT WED SEP 17 2014
A BACKDOOR COLD FRONT WILL DROP SOUTH ACROSS THE REGION
LATE THIS AFTERNOON AND EVENING. MOISTURE IS LACKING SO EXPECT ONLY
CLOUDS AS THE FRONT GOES BY. PLENTY OF MVFR CIGS BEHIND THE
FRONT...AND THINK THESE CIGS WILL MAKE IT INTO THE NORTH-CENTRAL AND
CENTRAL WISCONSIN TAF SITES. SOME CLEARING IS LIKELY ACROSS
NORTH-CENTRAL WISCONSIN LATE...WHICH WILL RESULT IN A FROST OR
FREEZE. SKIES WILL BECOME MOSTLY CLOUDY ONCE AGAIN THURSDAY
MORNING OVER N-C WISCONSIN WITH MVFR CIGS...BUT PARTLY SUNNY
FARTHER EAST.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 8 AM CDT THURSDAY FOR WIZ010>013-018-
019.
FREEZE WARNING FROM 1 AM TO 8 AM CDT THURSDAY FOR WIZ005.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 AM CDT WED SEP 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT WED SEP 17 2014
LATEST INFARED SATELLITE IMAGERY INDICATE STRATOCUMULUS DECK ACROSS
SOUTHERN MINNESOTA INTO IOWA. THIS IS IN ASSOCIATION WITH A WEAK
IMPULSE OVER SOUTHWEST MINNESOTA AND NORTHWEST IOWA EVIDENT ON
LATEST WATER VAPOR SATELLITE IMAGERY. LATEST 07Z SURFACE ANALYSIS
SHOWS RIDGE OF HIGH PRESSURE EXTENDING FROM NORTHERN ILLINOIS
INTO NORTHERN WISCONSIN. WITH CLEAR SKIES AND LIGHT WINDS EAST OF
THE MISSISSIPPI RIVER...TEMPERATURES HAVE FALLEN INTO THE MIDDLE
TO UPPER 30S ACROSS CENTRAL WISCONSIN PER LATEST 07Z METARS.
MAIN FORECAST CONCERN TONIGHT IS FOG POTENTIAL IN RIVER VALLEYS
AND CLOUD FORMATION OVER NORTHERN WISCONSIN.
THE LATEST 17.00Z GFS/NAM PUSH WEAK IMPULSE SOUTH OF THE FORECAST
AREA THIS MORNING AND THIS WILL CONTINUE TO ADVECT THE STRATOCUMULUS
DECK OVER THE FORECAST AREA THROUGH 18Z. ANY RESIDUAL MOISTURE
LEFT WITH DEPARTING IMPULSE WILL EVAPORATE DUE DAYTIME HEATING AND
ALLOW SKIES TO BECOME MOSTLY SUNNY AFTER 18Z.
FOCUS TURNS TO FOG POTENTIAL TONIGHT. THE LATEST 17.00Z
GFS/NAM/ECMWF CONTINUE TO PUSH WEAK SURFACE FRONT NORTH TO SOUTH
ACROSS THE FORECAST AREA THIS EVENING. ALL MODELS INDICATE 850MB
MOISTURE ALONG WEAK SURFACE FRONT AND PRODUCE CLOUDS EAST OF THE
MISSISSIPPI RIVER...MAINLY OVER CENTRAL WISCONSIN. THE QUESTION WILL
BE HOW FAR SOUTH AND WEST THE DECK OF CLOUDS WILL BE TO INHIBIT ANY
RIVER VALLEY FOG FORMATION AFTER 06Z THURSDAY. THE 17.00Z GFS/NAM
BUFKIT SOUNDINGS SHOW WINDS LIGHT ENOUGH UNDER INVERSION AFTER 06Z
THURSDAY AND NEAR SURFACE BOUNDARY LAYER MOISTENING. THIS WOULD
SUGGEST FOG IS POSSIBLE IN RIVER VALLEYS AND WILL DEPEND ON IF ANY
CLOUDS MOVE OVER SOUTHWEST AND WESTERN WISCONSIN TO INHIBIT
FORMATION OF FOG. FOR NOW...HAVE LEFT MENTION OF FOG IN RIVER
VALLEYS IN FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 318 AM CDT WED SEP 17 2014
THE 17.00Z GFS/NAM/ECMWF LINGER THE 900-850MB MOISTURE OVER
CENTRAL WISCONSIN INTO THURSDAY PER BUFKIT SOUNDINGS. IF CLOUDS
FORM AND LINGER OVER THIS AREA. TEMPERATURES MAY NOT REACH THE
CURRENT FORECAST HIGHS OVER CENTRAL WISCONSIN.
MAIN FORECAST CONCERNS THURSDAY NIGHT THROUGH SATURDAY ARE
PRECIPITATION CHANCES. THE 17.00Z GFS/NAM/ECMWF/GEM CONTINUE TO
INDICATE TIMING DIFFERENCES WITH SHORTWAVE TROUGH AND ASSOCIATED
SURFACE FRONT MOVING INTO THE GREAT LAKES REGION. THE 17.00Z ECMWF
IS TRENDING TOWARDS A BROADER AND MORE PROGRESSIVE SOLUTION THAN THE
GFS/GEM. THE 17.00Z GFS/GEM/ECMWF/NAM FOCUS LIFT/MOISTURE
TRANSPORT AND CONVERGENCE OVER THE NORTHERN SECTIONS OF THE
FORECAST AREA MAINLY AFTER 18Z FRIDAY IN ASSOCIATION WITH THE FIRST
IMPULSE. HENCE...HIGHER PRECIPITATION CHANCES OVER THIS AREA.
SHORTWAVE RIDGE REMAINS ENTRENCHED OVER THE SOUTHERN FORECAST AREA
AND ALLOW FOR LESSER TO NO PRECIPITATION CHANCES OVER THE SOUTHERN
FORECAST AREA FRIDAY.
MAIN SHORTWAVE TROUGH DIGS INTO THE GREAT LAKES REGION AND SURFACE
FRONT MOVES ACROSS THE FORECAST AREA FRIDAY NIGHT INTO SATURDAY
MORNING. WITH THE TIMING DIFFERENCES BETWEEN THE 17.00Z
GFS/NAM/ECMWF/GEM...CONFIDENCE IN EXACT TIMING OF THUNDERSTORMS
CONTINUES TO BE LOW. THE 17.00Z GFS/GEM/ECMWF/NAM INDICATE DECENT QG
FORCING/LIFT/MOISTURE TRANSPORT AND CONVERGENCE ASSOCIATED WITH
TROUGH/SURFACE FRONT FRIDAY NIGHT INTO SATURDAY MORNING. MUCH OF
THE AREA SHOULD SEE SHOWERS AND THUNDERSTORMS. MODELS CONTINUE TO
PROG HIGH PRECIPITABLE WATER VALUES...INSTABILITY AND SHEAR WITH
THE SURFACE FRONT/SHORTWAVE TROUGH. A FEW OF THE THUNDERSTORMS
COULD POTENTIALLY BECOME SEVERE.
SURFACE RIDGE BUILDS INTO THE GREAT LAKES REGION SUNDAY NIGHT INTO
TUESDAY AND PROVIDE DRIER WEATHER CONDITIONS ACROSS THE FORECAST
AREA. COOLER AIR WILL FILTER IN BEHIND THE SURFACE FRONT/SHORTWAVE
TROUGH AND TEMPERATURES SHOULD BE NEAR NORMAL EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CDT TUE SEP 16 2014
STILL SOME UNCERTAINTIES AS TO WHETHER FOG WILL FORM IN THE
MISSISSIPPI RIVER VALLEY TONIGHT. THE 17.02Z RAP AND 17.00Z NAM
BOTH CONTINUE TO SHOW THE WINDS JUST ABOVE THE SURFACE INCREASING
OVERNIGHT AS THE SURFACE HIGH OVER ILLINOIS MOVES OFF INTO THE
OHIO RIVER VALLEY. HAVE NOTICED THROUGH THE EVENING THAT THE FLAG
HERE AT THE OFFICE HAS BEEN MOVING AROUND AT TIMES AND THE VWP
WINDS FOR THE KARX RADAR HAVE BEEN SHOWING 10 KNOTS AT 1000 FEET
ALL EVENING WITH INCREASING WINDS ABOVE THAT. BOTH MODELS ALSO
CONTINUE TO SHOW SATURATION OCCURRING RIGHT AT THE SURFACE AND
WITH A 4 DEGREE TEMP/DEW POINT SPREAD AT 17.04Z THIS COULD ALLOW
SOME FOG TO FORM NEAR THE AIRPORT AND WILL CONTINUE WITH BCFG BUT
NOT SHOW ANYTHING MORE THAN THAT GIVEN THE WINDS ALOFT.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS A WEAK
COLD FRONT SLIDES THROUGH WEDNESDAY AFTERNOON FOLLOWED BY ANOTHER
AREA OF HIGH PRESSURE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1144 PM CDT TUE SEP 16 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 228 PM CDT TUE SEP 16 2014
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING AGAIN OVER WESTERN NORTH AMERICA WHILE TROUGHING
DOMINATES EASTERN CANADA INTO THE GREAT LAKES AND OHIO VALLEY. THIS
PLACES THE FORECAST AREA IN A SUBSIDENT NORTHWEST FLOW REGIME...
FAVORING DRY CONDITIONS AND HIGH PRESSURE AT THE SURFACE. LATEST
SURFACE ANALYSIS SHOWED THE HIGH CENTERED OVER ILLINOIS WITH A RIDGE
AXIS EXTENDING INTO WESTERN WI. AIRMASS OVER THE AREA HAS WARMED
SLIGHTLY FROM YESTERDAY WITH 925MB TEMPS UP TO 10C. HOWEVER...MORE
SUNSHINE AND A DRIER AIRMASS REFLECTED BY PRECIPITABLE WATER VALUES
OF 0.3-0.5 INCHES PER PRECIPITABLE WATER IMAGERY HAS ALLOWED
TEMPERATURES TO CLIMB INTO THE 60S.
THE SHORT TERM PERIOD AGAIN LOOKS QUIET...RESULTING FROM PLENTIFUL
DRY AIR IN PLACE OVER THE NEXT 24 HOURS TO PREVENT PRECIPITATION.
HOWEVER...THERE ARE A FEW ISSUES TO CONTEND WITH...
1. POTENTIAL FOR VALLEY FOG TONIGHT. THE RIDGE AXIS EXTENDING FROM
THE SURFACE HIGH IN ILLINOIS INTO WESTERN WI IS PROGGED TO STAY IN
PLACE THROUGH WEDNESDAY MORNING. WITH DRY AIR IN PLACE...LIGHT WINDS
AND CURRENTLY CLEAR SKIES...TEMPERATURES SHOULD DROP QUICKLY.
HOWEVER...THERE ARE 3 PROBLEMS FOR VALLEY FOG. THE FIRST IS THAT THE
AIR IS MUCH DRIER TODAY COMPARED TO YESTERDAY AT THIS TIME...AND ALL
RAIN FROM YESTERDAY HAS BEEN ABSORBED. SECOND...THE GFS...NAM AND
RAP HAVE ALL TRENDED STRONGER WITH THE WIND FIELD AFTER MIDNIGHT...
WITH POTENTIAL OF UP TO 20 KT SUGGESTED RIGHT ABOVE THE SURFACE.
THESE WINDS COULD REALLY HAMPER FOG AND EVEN STRATUS TRYING TO STICK
AROUND IN THE MISSISSIPPI VALLEY. THIRD...A NEW DISCOVERY TODAY IS
THAT BOTH THE GFS AND NAM SHOW A BAND OF MID CLOUDS MOVING INTO THE
WESTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. THESE CLOUDS MATCH
UP VERY WELL WITH ISENTROPIC LIFT SEEN ON THE 300K SURFACE...WHICH
COULD ALSO HAMPER FOG AND STRATUS FROM STICKING AROUND...EVEN IN THE
TRIBS. THUS...HAVE BACKED DOWN THE COVERAGE OF VALLEY FOG AND
STRATUS OVERNIGHT INTO WEDNESDAY MORNING.
2. TEMPS AND FROST POTENTIAL TONIGHT. RELATED TO THE VALLEY FOG
DISCUSSION ABOVE... READINGS IN CENTRAL WISCONSIN LOOK TO PLUMMET
AGAIN. FOLLOWED PREVIOUS FORECAST IN DROPPING TEMPERATURES TOWARDS
THE MID 30S. THEY SHOULD STAY HIGH ENOUGH TO PRECLUDE FROST
FORMATION...THOUGH. ALONG/WEST OF THE RIVER...INCREASING WIND AND
INCOMING CLOUDS RESULT IN WARMER READINGS.
3. BACKDOOR COLD FRONT WEDNESDAY AFTERNOON. THIS FRONT HAS BEEN
SHOWN FOR MANY DAYS TO COME INTO THE REGION FROM THE NORTH. DRY AIR
WILL PREVENT PRECIPITATION...HOWEVER...THE FRONT SHOULD PULL SOME
WARMER AIR IN AHEAD OF IT TO ALLOW FOR HIGHS TO BE ABOUT 5 DEGREES
WARM THAN TODAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 228 PM CDT TUE SEP 16 2014
QUIET WEATHER CONTINUES FOR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
AS A CANADIAN HIGH DROPS DOWN INTO THE GREAT LAKES REGION BEHIND THE
BACKDOOR COLD FRONT. MAY HAVE TO CONTEND WITH SOME STRATUS IN THE
WAKE OF THE FRONT...AS WELL AS AN INCREASING EAST-SOUTHEAST
WIND...BOTH OF WHICH COULD IMPACT VALLEY FOG FORMATION/PERSISTENCE.
MUCH OF THE COOLING BEHIND THE FRONT STILL APPEARS TO GET DEFLECTED
TO THE EAST...THUS HIGHS ON THURSDAY ARE ONLY ANTICIPATED TO BE
SLIGHTLY COOLER THAN WEDNESDAY.
MUCH OF THE LONG TERM FOCUS IS AFTER MIDNIGHT THURSDAY NIGHT THROUGH
SATURDAY. MODELS REMAIN IN GOOD AGREEMENT ON BUILDING UPPER RIDGING
INTO THE REGION ON FRIDAY...AHEAD OF A SHORTWAVE TROUGH CROSSING THE
NORTHERN ROCKIES. THIS SETS UP A FAIRLY SIGNIFICANT WARM ADVECTION
REGIME OVER THE FORECAST AREA...WITH 850MB TEMPS CLIMBING 8-10C
BETWEEN 00Z FRI AND 00Z SAT. THIS REGIME ALSO COMES WITH MORE
MOISTURE...AS PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.7 INCHES
AT 00Z FRI TO AROUND 1.5 INCHES BY 18Z FRI. THESE TWO PARAMETERS
INCREASING SIGNIFICANTLY BRINGS UP A CONCERN FOR ELEVATED
CONVECTION. 850MB MOISTURE TRANSPORT PROGS FROM THE 16.12Z
NAM/GFS/ECMWF WOULD SUGGEST POSSIBLE CONVECTION FIRING WEST OF I-35
IN MN AND IA BETWEEN 06-12Z FRI...THEN LIFTING NORTHEAST INTO
NORTHERN WI BY 00Z SAT AS CAPPING BUILDS IN. THUS...SOME SHOWER AND
THUNDERSTORM CHANCES PERSIST FOR FRI...ESPECIALLY NORTH OF I-90.
CAPE AND SHEAR PROFILES WOULD SUGGEST NO SEVERE WEATHER WITH THIS
ACTIVITY. GREATER CHANCES FOR WIDESPREAD RAIN LOOK TO COME AFTER
MIDNIGHT FRIDAY NIGHT INTO SATURDAY. THIS IS WHEN THE TROUGH MAKES
ITS WAY EAST AND THROUGH THE REGION...FOLLOWED WITH AN ASSOCIATED
SURFACE COLD FRONT FOR CONVERGENCE. PLENTIFUL MOISTURE CHARACTERIZED
BY THE AFOREMENTIONED 1.5 INCH PRECIPITABLE WATER WILL ALSO HELP.
HARD TO SAY AT THIS TIME IF THE MID LEVEL CIRCULATION OF TROPICAL
STORM ODILE OVER BAJA CALIFORNIA WILL GET PULLED UP INTO THE REGION
OR NOT. IF IT DOES...THE CHANCES FOR PRECIPITATION...AND HEAVY
PRECIPITATION AT THAT WOULD INCREASE. TIMING OF THE FRONT WILL BE
CRITICAL TO WHEN AND WHERE POTENTIAL EXISTS FOR SEVERE WEATHER.
16.12Z ECMWF POINTS TO FRIDAY EVENING ACROSS THE NORTHWEST HALF OF
THE FORECAST AREA...WHILE THE 16.12Z GFS WOULD BE SATURDAY AFTERNOON
OVER THE SOUTHEAST HALF.
SOMETHING ALSO TO KEEP A CLOSE EYE ON IS WINDS ON FRIDAY ACROSS
SOUTHEAST MN. WITH 40 TO PERHAPS AS HIGH AS 60KT SOUTHWEST
WINDS...STRONGEST IF YOU BELIEVE THE NAM...PROGGED BETWEEN 3000-5000
FT ABOVE THE GROUND...MIXING SHOULD EASILY CREATE GUSTS NEAR 30 KT.
THESE IN LATER FORECASTS COULD GET CLOSE TO WIND ADVISORY CRITERIA
IF MORE SUN OCCURS.
FOR SUNDAY INTO TUESDAY...MODELS REAMPLIFY TROUGHING OVER EASTERN
CANADA INTO THE GREAT LAKES REGION...SIMILAR TO WHAT IS GOING ON
TODAY. THERE REMAINS UNCERTAINTY IF A MORE POTENT SHORTWAVE WILL
DIVE THROUGH THE TROUGH AND THROUGH THE FORECAST AREA...BUT TRENDS
SEEM TO SUGGEST THAT THE TRACK OF SUCH WAVE WILL END UP NORTHEAST OF
THE AREA. THEREFORE...THE FORECAST STAYS DRY WITH THE COOLER AIR
STAYING TO THE NORTH AND EAST. STILL...WE SHOULD SEE TEMPERATURES
FALL BACK TO JUST BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CDT TUE SEP 16 2014
STILL SOME UNCERTAINTIES AS TO WHETHER FOG WILL FORM IN THE
MISSISSIPPI RIVER VALLEY TONIGHT. THE 17.02Z RAP AND 17.00Z NAM
BOTH CONTINUE TO SHOW THE WINDS JUST ABOVE THE SURFACE INCREASING
OVERNIGHT AS THE SURFACE HIGH OVER ILLINOIS MOVES OFF INTO THE
OHIO RIVER VALLEY. HAVE NOTICED THROUGH THE EVENING THAT THE FLAG
HERE AT THE OFFICE HAS BEEN MOVING AROUND AT TIMES AND THE VWP
WINDS FOR THE KARX RADAR HAVE BEEN SHOWING 10 KNOTS AT 1000 FEET
ALL EVENING WITH INCREASING WINDS ABOVE THAT. BOTH MODELS ALSO
CONTINUE TO SHOW SATURATION OCCURRING RIGHT AT THE SURFACE AND
WITH A 4 DEGREE TEMP/DEW POINT SPREAD AT 17.04Z THIS COULD ALLOW
SOME FOG TO FORM NEAR THE AIRPORT AND WILL CONTINUE WITH BCFG BUT
NOT SHOW ANYTHING MORE THAN THAT GIVEN THE WINDS ALOFT.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS A WEAK
COLD FRONT SLIDES THROUGH WEDNESDAY AFTERNOON FOLLOWED BY ANOTHER
AREA OF HIGH PRESSURE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
300 AM PDT FRI SEP 19 2014
.SYNOPSIS...
WEAK UPPER LEVEL LOW PRESSURE WILL BRING BELOW NORMAL TEMPERATURES
TO MUCH OF THE REGION THROUGH THE WEEKEND. TEMPERATURES WILL LIKELY
WARM TO NEAR NORMAL EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
HIGH PRESSURE BRIEFLY RETURNS. ANOTHER TROUGH OF LOW PRESSURE MAY
BRING A COOLING TREND FOR THE SECOND HALF OF NEXT WEEK.
&&
.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED
PLENTY OF LOW LEVEL MOISTURE LINGERING ACROSS COAST AND VALLEYS N OF
POINT CONCEPTION...WHILE LOW CLOUDS WERE MORE RANDOM IN NATURE FOR
AREAS SOUTH OF POINT CONCEPTION. LOW CLOUDS SHOULD FILL IN ACROSS
COAST AND VALLEYS OF LOS ANGELES...VENTURA AND SANTA BARBARA
COUNTIES BY DAWN. THERE WILL BE ENOUGH LOW LEVEL LIFT TO CAUSE SOME
PATCHY DRIZZLE TO OCCUR JUST ABOUT ANYWHERE WEST OF THE MOUNTAINS
THIS MORNING. LATEST ACARS SOUNDING NEAR LAX SHOWED A VERY WEAK
INVERSION IN PLACE WHICH MAKES SENSE WHY CLOUDS ARE NOT MORE UNIFORM
S OF POINT CONCEPTION THIS MORNING. WIND PATTERNS ARE INTERESTING
THIS MORNING. OVER THE COASTAL AREAS INTO LA COUNTY THE FLOW IS
MOSTLY CYCLONIC NW BECOMING SW OVER LA COUNTY. HOWEVER...NORTHERLY
WINDS WERE OCCURRING OVER THE MOUNTAINS AND SAN JOAQUIN VALLEY. THIS
NORTHERLY FLOW WAS CAUSING ADDITIONAL CLOUDS TO PILE UP ALONG THE
NORTHERN SLOPES OF THE LOCAL MOUNTAINS THIS MORNING INCLUDING THE
I-5 CORRIDOR.
SYNOPTICALLY...A CLOSED 578 DM UPPER LOW CURRENTLY OFF THE CENTRAL
COAST WILL DRIFT SLOWLY SOUTH JUST WEST OF POINT CONCEPTION BY THIS
AFTERNOON. THE PROXIMITY OF THE UPPER LOW WILL ALLOW FAVORABLE COOL
CYCLONIC FLOW OVER MOST OF LOS ANGELES...VENTURA AND SANTA BARBARA
COUNTIES TODAY. THERE IS NOT MUCH IN THE WAY OF MOISTURE ASSOCIATED
WITH THE UPPER LOW...BUT THERE WILL BE PLENTY LOW CLOUDS LINGERING
ACROSS THE COAST AND VALLEYS THROUGH THIS MORNING AND INTO THE
AFTERNOON ACROSS MOST COASTAL AREAS. RAP AND NAM-WRF MODELS
INDICATED THAT THERE WOULD BE ENOUGH INSTABILITY AND LIMITED MID
LEVEL MOISTURE TO WARRANT A SLIGHT CHANCE FOR SHOWERS OR
THUNDERSTORMS TO DEVELOP OVER THE VENTURA COUNTY MOUNTAINS AS WELL
AS PORTIONS OF THE SANTA BARBARA COUNTY MOUNTAINS THIS AFTERNOON AND
EVENING HOURS. TEMPERATURES WILL CONTINUE TO TREND COOLER THROUGH
SATURDAY AS THE UPPER LOW MOVES DIRECTLY OVER SBA/VENTURA
COUNTIES SATURDAY AFTERNOON. THERE IS NOT MUCH DIFFLUENCE ASSOCIATED
WITH THE UPPER LOW FOR SATURDAY AND MODELS WERE NOT PICKING UP ON
ANY ADDITIONAL MOISTURE OR CONVECTIVE PARAMETERS ACROSS THE LOCAL
MOUNTAINS. WILL LET LATER SHIFT LOOK CLOSER TO SEE IF SLIGHT CHANCE
POPS WILL BE NEEDED FOR SAT IN THE LOCAL MTNS ONCE AGAIN.EXPECT HIGH
TEMPS TO BE NEAR OR JUST BELOW NORMAL TODAY AND SATURDAY.
BY SUNDAY...THE UPPER LOW WILL FILL IN AND MOVE NE INTO NEVADA
ALLOWING HEIGHTS AND THICKNESS LVLS TO RISE. THERE WILL BE NIGHT
THROUGH MORNING LOW CLOUDS BUT A QUICKER BURNOFF AND HIGH TEMPS WILL
BE A FEW DEGREES HIGHER...ESPECIALLY ACROSS INTERIOR
LOCATIONS...WITH WARMEST VALLEY LOCATIONS IN THE MID 80S...AND MID
TO UPPER 70S ALONG THE COAST.
.LONG TERM (MON-THU)...BOTH GFS AND ECMWF STAY IN PRETTY GOOD
AGREEMENT OVER THE LONG TERM PERIOD. A WEAK RIDGE WILL BEGIN TO
BUILD OVER BAJA CALIFORNIA WHILE MUCH OF NORTHERN CALIFORNIA REMAIN
UNDER A BROAD UPPER TROUGH THROUGH WED. EXPECT NIGHT THROUGH MORNING
LOW CLOUDS FOR COASTAL AREAS AND POSSIBLY SOME COASTAL VALLEYS
THROUGH WED MORNING. TEMPS WILL CONTINUE TO REBOUND MONDAY AND
TUESDAY WITH HIGHS REACHING THE LOWER 90S ACROSS WARMEST VALLEY
LOCATIONS. FOR WED AND THU...A BROAD UPPER TROUGH WILL BEGIN TO DIG
FARTHER SOUTH. THE GFS IS SHOWING A SHARPER TROUGH WHICH WOULD MEAN
MORE SIGNIFICANT COOLING BY THURSDAY...WHERE THE EUROPEAN MODEL IS
LESS PRONOUNCED. AT THIS POINT HAVE TRENDED HIGH TEMPS DOWN SLIGHTLY
FOR WED...WITH A FEW MORE DEGREES OF COOLING FOR THURSDAY TO
SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...WILL BE UPDATED WITH 12Z TAFS.
&&
.MARINE...18/800 PM
SMALL CRAFT ADVISORY CONDITIONS IN THE VICINITY OF THE NORTHERN
CHANNEL ISLANDS EXTENDING INTO THE WESTERN SANTA BARBARA CHANNEL AND
SOUTHWARD TO SAN NICOLAS ISLAND WILL CONTINUE THROUGH LATE TONIGHT.
WINDS ARE BEGINNING TO SUBSIDE OVER PZZ655 AND MAINLY LIGHT WINDS
EXIST ELSEWHERE. LARGER SHORT PERIOD SEAS WILL BEGIN TO SUBSIDE LATE
TONIGHT AS WINDS BEGIN TO EASE.
SEAS FROM LOW PRESSURE SYSTEM OVER THE NORTHERN CA OFFSHORE WATERS
WILL ARRIVE FROM THE WEST NORTHWEST DIRECTION THROUGH SATURDAY
NIGHT. THE SOUTH SWELL WILL CONTINUE TO SUBSIDE WHILE LINGERING
THROUGH SATURDAY. A 982MB LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP
NEXT WEEK TUESDAY OVER THE EASTERN PACIFIC AND SWELLS GENERATED BY
NEAR STORM FORCE WINDS ARE EXPECTED TO ARRIVE FROM 295-310 DEGREES
WEDNESDAY AFTERNOON AND PEAK WEDNESDAY NIGHT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...KAPLAN
AVIATION/MARINE...DB
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
405 AM EDT FRI SEP 19 2014
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN AMPLIFIED
UPPER LEVEL PATTERN OVER THE CONUS THIS MORNING. MAIN NORTHERN
STREAM FLOW ARRIVES OVER THE PACIFIC NORTHWEST AND RIDGES UP INTO
SOUTH-CENTRAL CANADA OVER TOP A LARGE RIDGE ACROSS THE
ROCKIES/CENTRAL PLAINS. THE FLOW THE DIVES SOUTHEAST INTO LONGWAVE
TROUGHING OVER THE ENTIRE EASTERN CONUS. OUR FORECAST AREA RESIDES
WITHING THE BASE OF THIS EASTERN CONUS TROUGH...AND IT WILL BE A
SHORTWAVE IMPULSE/ENERGY ROUNDING THE TROUGH BASE TODAY AND TONIGHT
THAT WILL BRING SOME SHOWERY AND CLOUDY WEATHER TO THE REGION TODAY.
SHORTWAVE ENERGY CAN CURRENTLY BE SEEN ON WV IMAGERY DROPPING
SOUTHEAST DOWN THE BACKSIDE OF THE TROUGH OVER THE SOUTHERN MS
VALLEY. THIS FEATURE WILL CONTINUE TO PROGRESS SOUTHEASTWARD TODAY
REACHING THE NE GULF OF MEXICO AND EVENTUALLY THE NORTHERN/CENTRAL
FL PENINSULA. HOWEVER...THE SYNOPTIC LIFT IS AHEAD OF THE
FEATURE...SO EXPECTING SHOWERS TO ARRIVE LONG BEFORE THE SHORTWAVE
AXIS APPROACHES OUR VICINITY. AS THE ENERGY BEGINS TO ARRIVE OVER
THE NORTH-CENTRAL GULF COAST...HAVE WATCHED CLOUD TOPS COOL THE PAST
FEW HOURS...WITH SHOWERS/AREAS LIGHT RAIN BREAKING OUT TO THE SOUTH
OF THE FL PANHANDLE PER EGLIN/TLH RADARS. MUCH OF THE REFLECTIVITY
HAS TENDED TO BE ALOFT SO FAR...BUT THE COLUMN IS QUICKLY MOISTENING
AND MORE AND MORE OF THIS WILL START TO REACH THE GROUND OVER THE
COMING HOURS. MODELS HAVE BEEN STRUGGLING WITH THEIR HANDLING OF
THIS MORE NORTHERN PRECIP ZONE...HOWEVER LATEST RAP IS BEGINNING TO
CATCH ON...AND HAS BEEN BECOME MORE AGGRESSIVE WITH ITS PRECIP PUSH
TOWARD THE NATURE COAST LATER THIS MORNING. MORE ABOUT THAT BELOW.
AT THE SURFACE...FORECAST AREA SITS BETWEEN A LARGE EXPANSE OF HIGH
PRESSURE OVER THE EASTERN CONUS...AND A FRONTAL BOUNDARY/SURFACE
TROUGH EXTENDING ACROSS THE EASTERN GULF/SOUTH FLORIDA. PRESSURE
GRADIENT IS CURRENTLY RATHER LOOSE...WITH JUST A LIGHT EASTERLY
FLOW...HOWEVER...AS THE ENERGY APPROACHES...A KINDA WEDGE EFFECT
TAKES PLACE ALLOWING THE SURFACE HIGH TO TRY AND WORK SOUTHWARD.
THIS RIDGING SOUTHWARD WORKS TO TIGHTENS THE GRADIENT OVER THE NE
GULF AND WILL LIKELY SEE SOME BREEZY CONDITIONS FOR THE COASTAL
WATERS NORTH OF ENGLEWOOD LATER TODAY INTO TONIGHT. CURRENT LAND
BREEZE CONVERGENCE OVER THE COASTAL WATERS ALONG WITH SOME SLOW
INCREASE IN SYNOPTIC FORCING IS ALLOWING FOR SCT STORMS OFFSHORE
THIS MORNING...THESE ARE GENERALLY PROGRESSING SLOWLY WESTWARD WITH
THE LOW LEVEL FLOW. IT IS THE MORE SYNOPTIC SCALE ACTIVITY STILL
OVER THE NORTH-CENTRAL GULF THAT WILL EVENTUALLY GIVE US OUR SHOWERS
LATER TODAY.
&&
.SHORT TERM (TODAY THROUGH SATURDAY)...
NOT THE EASIEST OF FORECASTS IN TERMS OF ADDING A LOT OF SPATIAL AND
TEMPORAL DETAIL TO THE RAIN CHANCES AND TEMPERATURES. FAIRLY
CONFIDENT THAT MOST PLACES WILL SEE SOME RAIN BEFORE THE DAY IS
THROUGH...HOWEVER...VERY SUBTLE DIFFERENCES IN THE GUIDANCE ARE
RESULTING IN SOME FAIRLY SIGNIFICANT DIFFERENCES IN THE PRECIP
PATTERNS. HAVE BEEN MENTIONING THE PAST COUPLE NIGHTS...THAT IT WILL
WOULD SEEM VERY DIFFICULT THIS TIME OF YEAR WITH THE FORCING
PROJECTED TO NOT SEE NUMEROUS SHOWERS BREAKING OUT OF THE EASTERN
GULF AND ROLLING ONSHORE. THE GFS HAS AN INTERESTING SCENARIO FROM A
NWP PERSPECTIVE WHERE IT SHOWS MAINLY LIGHT PRECIP OF THE STABLE
VARIETY INTO THE NATURE COAST...AND MAINLY PRECIP FROM THE
CONVECTIVE SCHEMES FURTHER SOUTH. NOW...THIS MAKES SENSE GIVEN THE
THERMODYNAMIC PROFILE FROM NORTH TO SOUTH...BUT RAISES QUESTIONS
ABOUT WHETHER THE ACTUAL MOISTURE SURGE NORTHWARD IS BEING
ARTIFICIALLY SUPPRESSED BY THIS NWP CONVECTIVE PROCESS. THIS MIGHT
ACCOUNT FOR WHY SOME OF THE OTHER MEMBERS ARE STRUGGLING TO PRODUCE
PRECIP INTO THE NATURE COAST...AND IF TRUE SHOULD SUGGEST A WETTER
DAY UP THERE THAN HAS BEEN PREVIOUS FORECAST. AS WAS MENTIONED ABOVE
THE LATEST RAP SEEMS TO BE GRABBING ONTO THE PRECIP TRENDS OFF THE
FL PANHANDLE AND IS CLOSER TO THE GFS SOLUTION FOR MORE SHOWER
ACTIVITY OVER THE NATURE COAST TO THE NORTH OF TAMPA BAY. WILL TREND
TOWARD MORE SHOWERS IN THE FORECAST AND SHOW LIKELY POPS FOR ALL OF
OUR NORTHERN ZONES.
SO LETS BREAK IT DOWN...DECENT LATE SEPT SHORTWAVE WILL APPROACH
FROM THE NW TODAY. DEEP LAYER Q-VECTOR CONVERGENCE ARRIVES AHEAD OF
THIS FEATURE ALONG WITH A FAIRLY DIFFLUENT UPPER LEVEL PATTERN OVER
THE PENINSULA. THIS UPPER LEVEL SUPPORT WILL BE FED BY MODEST BUT
DEEP LAYER ISENTROPIC UPGLIDE BETWEEN THE 300-315K SURFACES. THE
UPGLIDE IS CERTAINLY NOT STRONG...BUT IT IS THERE. THE RESULT IS A
MOSTLY CLOUDY FRIDAY...WITH PERIODS OF SHOWERS. A FEW RUMBLES OF
THUNDER ARE POSSIBLE...BUT ALL IN ALL...NOT GOING FOR MUCH IN THE
WAY OF THUNDER ACTIVITY. SHOWALTER INDICES ARE ALL ABOVE ZERO...AND
WELL ABOVE ZERO TO THE NORTH OF TAMPA BAY. IF WE ARE GOING TO SEE
ANY STORMS THAT WOULD FIT THE BILL OF "FREQUENT LIGHTNING" IT SHOULD
BE DOWN TOWARD SARASOTA COUNTY AND SOUTHWARD. SHOWALTER INDICES
THIS FAR SOUTH ARE POSITIVE...BUT IN THE RANGE OF 1-3 RANGE...WHICH
SUGGESTS AT LEAST SOME ELEVATED INSTABILITY IS EXPECTED.
SO...NOT EXPECTING IT TO RAIN ALL DAY IN ANY PARTICULAR PLACE...BUT
RATHER BE ON THE PERIODIC SIDE. LOCALLY HEAVIER RAINFALL AMOUNTS ARE
POSSIBLE...ESPECIALLY WITH MORE CONVECTIVE TYPE PRECIP SOUTH OF
TAMPA BAY THIS AFTERNOON...HOWEVER...GENERALLY EXPECTING TOTALS OF
LESS THAN 1/2 INCH. THE CLOUDS AND PERIODS OF RAIN WILL HOWEVER KEEP
TEMPERATURES DOWN. MAXED OUT TEMPS IN THE 80S TODAY...AND WHERE THE
SHOWERS START EARLY...GETTING TEMPS OUT OF THE LOWER 80S MIGHT BE A
CHALLENGE.
TONIGHT INTO SATURDAY THE FORECAST DOES NOT GET ANY EASIER. THE BEST
SYNOPTIC FORCING CERTAINLY EXITS TO OUR EAST...HOWEVER...THE UPPER
TROUGH TENDS TO CLOSE OFF ALONG THE SE CONUS COAST AND LINGER BACK
SOUTHWEST INTO THE GULF OF MEXICO. DEEP CYCLONIC FLOW OVER THE WARM
WATERS OF THE OCEAN MEANS SCT SHOWERS COULD POP UP JUST ABOUT ANY
TIME. THE ACTIVITY WILL BE MOST PREVALENT DURING THE OVERNIGHT
ACROSS THE COASTAL WATERS...BUT ANY DAYTIME HEATING DURING
SATURDAY...AND THE SCT SHOWERS AND STORMS WILL BURST FORTH ACROSS
THE PENINSULA AS WELL. SOME QUESTION AS TO HOW MUCH SUN WE WILL SEE
ON SATURDAY. THIS IS A SITUATION WHERE MORE BREAKS OF SUN MAY LEAD
TO HIGHER RAIN CHANCES THE SECOND HALF OF THE DAY...ESPECIALLY IF
THIS TERRESTRIAL HEATING LEADS TO A WEAK SEA-BREEZE...AS SUGGESTED
BY THE NAM. PLAYED IT DOWN THE MIDDLE OF THE ROAD WITH CHANCE POPS
40-50% FOR SATURDAY. THESE NUMBERS COULD EASILY BE HIGHER ACROSS THE
INTERIOR...AND WILL LET THE NEXT SHIFT RE-EVALUATE THE POTENTIAL FOR
DIURNAL HEATING AND AND INSTABILITY.
&&
.LONG TERM (SUNDAY THROUGH NEXT THURSDAY)...
THE PERIOD STARTS WITH AN UPPER RIDGE FROM THE SOUTHERN PLAINS TO
THE CANADIAN ROCKIES AND UPPER LEVEL TROUGHINESS FROM THE GREAT
LAKES REGION TO THE SOUTHEAST U.S. WHERE A BROAD CLOSED LOW WAS OFF
THE COAST. AT THE SURFACE HIGH PRESSURE SPRAWLED ACROSS THE NORTHERN
AND MUCH OF THE CENTRAL PLAINS WHILE A FRONT STRETCHED FROM THE
SOUTH-CENTRAL PLAINS TO THE GREAT LAKES. ATLANTIC HIGH PRESSURE
RIDGED ACROSS THE MID-ATLANTIC COAST INTO THE SOUTHEASTERN STATES. A
LOW EAST OF THE SC/GA COAST TRAILED A TROUGH THAT REACHED ACROSS FL
TO THE SOUTHEASTERN GULF.
THROUGH MON...THE UPPER RIDGE ROTATES AROUND THE SOUTHERN PLAINS
WHILE THE UPPER TROUGH SHIFTS EAST. THE UPPER LOW AND IT/S SURFACE
REFLECTION TRACKS NORTHWARD OVER THE OPEN ATLANTIC ALTHOUGH THE
TRAILING TROUGH CONTINUES ACROSS FL AND THE BAHAMAS. THE COLD FRONT
DROPS DOWN ACROSS THE GULF COAST AND SOUTHEAST STATES AS THE PLAINS
HIGH PRESSURE SHIFTS TO THE GREAT LAKES.
FOR TUE THROUGH THU...THE UPPER RIDGE MOVES EAST BUT WEAKENING
TROUGHINESS LINGERS DOWN THE EASTERN SEA BOARD THROUGH WED. THE
SURFACE HIGH SLIPS FROM THE GREAT LAKES TO NEW ENGLAND COASTAL
AREAS WITH THE COLD FRONT CONTINUING A SOUTHWARD TREK DOWN FL
AS IT RUNS OUT OF ENERGY AND SLOWS CONSIDERABLY.
THE FORECAST...THE LATEST GFS AND ECMWF ARE FAIRLY CONSISTENT
ALTHOUGH THE GFS DIVERGES ON THE LAST DAY WITH A ROBUST INVERTED
SURFACE TROUGH OFF THE FL/GA/SC COAST. FOR NOW HAVE DISCOUNTED THIS
AND USED A GFS/ECMWF BLEND FOR THE MOST PART. THE LINGERING TROUGH
THEN THE FRONT WILL PROVIDE ADEQUATE MOISTURE AND LIFT FOR SLIGHT
CHANCE TO CHANCE SHOWERS AND STORMS. ALTHOUGH SOME SLIGHTLY DRIER
AIR WORKS IN BEHIND THE FRONT THE ATMOSPHERE QUICKLY MOISTENS BACK
UP. TEMPERATURES WILL RUN NEAR TO JUST BELOW NORMAL FOR THE LOWS
WHILE THE HIGHS ARE WITH IN A COUPLE OF DEGREES OF NORMAL.
&&
.AVIATION...
TAFS ARE VFR THIS MORNING AND DO NOT EXPECT ANY SIGNIFICANT
RESTRICTIONS INTO THE MIDDLE MORNING HOURS. THEREAFTER EXPECTING SCT
TO NMRS SHOWERS TO ARRIVE AT ALL TERMINALS. CLOUD BASES WILL BE
LOWERING...BUT DO NOT EXPECT A WIDESPREAD MVFR EVENT FOR THE SECOND
HALF OF THE DAY. HOWEVER...PERIODS OF MVFR CIGS/VIS ARE CERTAINLY
POSSIBLE WITH THE SHOWERS. BETTER CHANCES FOR A PERIOD OF MVFR CIGS
AFTER SUNSET THIS EVENING AND INTO THE OVERNIGHT. HAVE NOT INCLUDED
MENTION IN THE TAFS QUITE YET...BUT WILL NEED TO BE MONITORED
CLOSELY THROUGH THE DAY.
&&
.MARINE...
EAST TO NORTHEAST WINDS ARE EXPECTED TO INCREASE TODAY INTO EARLY
SATURDAY AS THE PRESSURE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE TO
OUR NORTH AND A SURFACE TROUGH TO OUR SOUTH. THE EASTERLY FLOW MAY
APPROACH CAUTIONARY LEVELS AT TIMES LATER TODAY AND
TONIGHT...ESPECIALLY TO THE NORTH OF ENGLEWOOD. IN ADDITION NUMEROUS
SHOWERS AND ISOLATED STORMS WILL BE IN THE FORECAST FOR MUCH OF
TODAY. WINDS AND RAIN CHANCES WILL DIMINISH FOR THE SECOND HALF OF
THE WEEKEND AND INTO THE EARLY PORTION OF NEXT WEEK.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH THE UPCOMING WEEKEND. NUMEROUS
SHOWERS ARE EXPECTED TODAY ALONG WITH LOTS OF CLOUDS AND COOLER
TEMPERATURES. SHOWERS WILL CONTINUE INTO THE WEEKEND...BUT COVERAGE
AND DURATIONS SHOULD BE LESS THAN TODAY. RELATIVE HUMIDITY WILL
REMAIN WELL ABOVE CRITICAL LEVELS THE NEXT SEVERAL DAYS.
NO SIGNIFICANT FOG EVENTS ARE EXPECTED THE NEXT COUPLE OF
NIGHT...HOWEVER PATCHY FOG IS EXPECTED AFTER MIDNIGHT TONIGHT INTO
EARLY SATURDAY MORNING TO THE NORTH OF I-4.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 87 72 86 73 / 70 30 40 40
FMY 88 72 86 72 / 80 50 50 40
GIF 87 70 87 71 / 80 30 50 50
SRQ 87 72 84 72 / 80 40 40 40
BKV 86 68 87 68 / 60 20 50 50
SPG 86 74 86 75 / 80 30 40 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DSS...RUDE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
325 AM EDT FRI SEP 19 2014
.DISCUSSION...
...WEAK LOW TO DEVELOP OFF OUR SE COAST TONIGHT/SATURDAY...
CURRENT...QSTNRY FRONT LIES NEAR THE FLORIDA-GEORGIA BORDER EARLY
THIS MORNING...WITH A WEAK SURFACE TROUGH AXIS FARTHER SOUTH...
EXTENDING FROM OFFSHORE FMY TO JUST NORTH OF GRAND BAHAMA ISLAND.
WATER VAPOR AND RUC IMAGERY SHOW CYCLONIC FLOW ALOFT...WITH A MID
LEVEL SHORT WAVE TROUGH AXIS...FROM MS/AL THRU INTO THE APPALACHIAN
SPINE...DROPPING SE TWD THE STATE. STATEWIDE RADAR MOSAIC STARTED
OFF FAIRLY QUIET...HOWEVER PROLIFERATION OF MARINE CONVECTION HAS
BEEN ONGOING...MAINLY TO THE SOUTH AND WEST OF ECFL. ACTIVITY HAS
BEEN AIDED BY INCREASINGLY DIFFLUENT/WEAKLY DVGT H25 FLOW.
TODAY/TONIGHT...
THE WELL-ADVERTISED DEVELOPMENT OF THE TRANSIENT POSITIVE TILT
CUTOFF MID LEVEL LOW AND ATTENDANT SURFACE WAVE/LOW FORMATION OFF
TO OUR E-SE REMAINS ON TAP FOR THE SHORT RANGE. 00Z MODEL RAOBS
INDICATE SIGNIFICANT "TOP-DOWN" MOISTENING OF THE LOCAL AIR
MASS...WHICH WILL VERY LIKELY LIMIT INSOLATION AND KEEP MAX TEMPS
DOWN MOSTLY IN THE L-M80S FOR MOST AREAS. INCREASING FORCED ASCENT
SHOULD RESULT IN BREAKOUT OF LIGHT RAIN WITH EMBEDDED WEAK
CONVECTION...ESPECIALLY LATE AFTERNOON-EARLY EVENING. AS THE LOW
BEGINS TO TAKE SHAPE JUST OFF THE SEFL COAST TONIGHT...CONTINUED
ASCENT ALOFT...INCREASING LOW LEVEL CYCLONIC/CONVGT FLOW NEAR/ALONG
THE COAST COUPLED WITH WRAP BACK MOISTURE AND THE NOCTURNAL INCREASE
IN MARINE INSTABILITY SHOULD RESULT IN DECENT CHC FOR POPS...
ESPECIALLY ALONG COASTAL AREAS WELL INTO THE OVERNIGHT HOURS.
SAT-SUN...
BOTH THE 19/00Z GFS AND 18/12Z ECMWF SIMILAR IN SHOWING AN UPPER
LEVEL LOW MOVING ACROSS THE UPPER TIER OF THE U.S. CATCHING THE
CLOSED LOW EAST OF FLORIDA AND JUST NORTH OF GRAND BAHAMA ISLAND AND
LIFTING IT NORTHEAST TO NEW ENGLAND AND EASTERN CANADA. ENOUGH
MOISTURE PRESENT SATURDAY AND A VORT MAX PROVIDING SUFFICIENT LIFT
AS IT ROUNDS THE BASE OF THE UPPER LOW OVER THE SOUTHEAST AND MID
ATLANTIC COASTAL REGIONS TO PRODUCE LIKELY...60 POP... RAIN CHANCES
SATURDAY AFTERNOON AND CHANCE...30-50 POP NORTH TO SOUTH...ON SUNDAY
AS MOISTURE RIBBON SLIDES DOWN THE STATES INTO SOUTHERN FLORIDA.
HIGHS MID AND UPPER 80S BOTH DAYS. LOWS SUN AND MON MORNING LOW 70S
EXCEPT UPPER 60S WEST OF INTERSTATE 95 INDIAN RIVER TO MARTIN AND
WEST ACROSS SOUTH OSCEOLA AND OKEECHOBEE COUNTIES.
MON...
STRONGER UPPER LEVEL TROUGH PUSHES ACROSS THE SOUTHEAST AND FLORIDA.
THE STRONGER SOUTHWEST FLOW AHEAD OF THE TROUGH PUSHES MOISTURE BACK
INTO CENTRAL FLORIDA. THE MOISTURE RETURN IS ENOUGH TO PUT 50 POP
OVER THE SOUTHERN AREAS AND RAIN CHANCES DECREASING TO AROUND 30
PERCENT ORLANDO AND NORTH. SOUTHWEST FLOW HELPS TO PUSH AFTERNOON
HIGHS INTO THE LOWER 90S EXCEPT RIGHT AT THE COAST AND DOWN WIND OF
LAKE OKEECHOBEE.
TUE-THU...
HIGH PRESSURE BUILDS INTO THE EASTERN THIRD OF THE U.S. AND RIDGES
SOUTH ACROSS FLORIDA RESULTING IN AN EASTERLY FLOW TUE AND WED. ON
THU THE GFS APPEARS AS IF IT MAY BE OVERDONE IN THE DEVELOPMENT OF A
SHARP INVERTED TROUGH ALONG THE FL EAST COAST AND THE SERN SEABOARD
THROUGH LATE NEXT WEEK. THE ECMWF FOR THE SAME MODEL RUN OF 19/00Z
SHOWS A MUCH WEAKER/DIFFUSE FEATURE. SUFFICIENT MOISTURE WILL EXIST
FOR AT LEAST MID RANGE SCATTERED POPS WITH SHOWERS BEING DOMINANT
PRECIP TYPE...ALONG WITH A SLIGHTLY LOWER CHC FOR TS...AS THE ECSB
WILL BE DIFFUSE/FAST MOVING IN A MODERATE ONSHORE FLOW REGIME.
&&
.AVIATION...INCREASING THREAT FOR SHOWERS THROUGHOUT THE DAY WITH TS
COVERAGE LIKELY TO ISOLD DUE TO THICKENING CLOUD COVER LIMITING SFC
HEATING. 06Z PACKAGE DID NOT INCLUDE VSBY RESTRICTIONS IN WHAT WILL
BE MOSTLY LIGHT RAIN AND PSBLY SOME HEAVIER EMBEDDED CONVECTION. AM
LEANING TWD PREVAILING MVFR VSBYS...MAINLY FROM VRB NWD LATE TODAY
INTO TONIGHT.
&&
.MARINE...TODAY/TONIGHT...DECAYING LONG PD (11-13S) SWELL FROM VERY
DISTANT T.S. EDOUARD WILL GIVE WAY TO INCREASING WIND CHOP ON NORTH
SIDE OF DEVELOPING SFC TROUGH/LOW OFF OUR SE COAST THROUGH TONIGHT.
AS SEAS BUILD SLIGHTLY TO 3-4FT AS PDS WILL SHORTEN...AND WAVE MODEL
GUIDANCE IS AT A TOSS UP W/R/T DOMINANT PDS. USED SORT OF A BLEND...
TRENDING FROM THE WNAWAVE HGTS/PDS EARLY TODAY...MORE TWD THE NWPS
MODEL FOR TONIGHT.
SAT-SUN...LOW EAST OF THE FLORIDA PENINSULA GIVES THE WINDS MORE OF
A NORTHERLY COMPONENT SAT SHIFTING TO THE WEST SUN AS THE LOW LIFTS
NORTHEAST AND AWAY FROM FLORIDA. ON SUN...THE WESTERLY WINDS SUN
LOOK LIGHT ENOUGH TO ALLOW AN AFTERNOON TO FORM BUT STAY AT THE
COAST.
MON-TUE...SOUTHWEST FLOW AHEAD OF A TROUGH BECOMES LIGHT AND
VARIABLE MON BEFORE SHIFTING TO THE NORTHEAST AND EAST TUE AS HIGH
PRESSURE OVER THE EASTERN U.S. RIDGES ACROSS THE SOUTHEAST AND INTO
FLORIDA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 83 72 86 71 / 60 50 50 30
MCO 85 71 87 70 / 60 40 50 30
MLB 84 74 85 71 / 70 50 60 30
VRB 84 72 87 70 / 70 50 60 30
LEE 84 70 88 71 / 60 40 40 30
SFB 85 70 88 72 / 60 40 50 30
ORL 85 71 87 72 / 60 40 50 30
FPR 85 73 86 69 / 70 50 60 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS JACKSON KY
407 AM EDT FRI SEP 19 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM EDT FRI SEP 19 2014
THROUGH TONIGHT...UPPER LEVEL RIDGING CURRENTLY CENTERED OVER THE
PLAINS STATES WILL BUILD EAST INTO THE LOWER OH VALLEY REGION TODAY
AND INTO TONIGHT. MEANWHILE A WEAK UPPER LOW/TROUGH OF LOW PRESSURE
WILL REMAIN ACROSS THE SOUTHEASTERN CONUS. FURTHER TO THE NORTHWEST A
SERIES OF SHORTWAVES IS EXPECTED TO LEAD TO AN UPPER LEVEL TROUGH
WORKING INTO THE GREAT LAKES REGION BY THE END OF THE PERIOD. AT THE
SFC...HIGH PRESSURE CURRENTLY CENTERED OVER QUEBEC AND EXTENDING
SOUTHWEST INTO THE OH VALLEY REGION WILL MOVE EAST SOUTHEAST TO NEAR
CAPE COD THIS EVENING AND THEN OFF THE NORTHEAST US COAST TONIGHT AND
INTO SATURDAY. AS THE HIGH MOVES EAST...AN INVERTED TROUGH IS
EXPECTED TO DEVELOP ACROSS THE REGION TODAY AND THEN SHIFT WEST AND
WEAKEN TONIGHT. TO THE EAST OF THE CREST OF THE APPALACHIANS...A
RIDGE OF HIGH PRESSURE IS EXPECTED TO EXTEND SOUTHWEST FROM THIS SFC
HIGH INTO THE APPALACHIANS GENERALLY ALONG OR JUST TO THE EAST OF THE
BLUE RIDGE MOUNTAINS LATER TODAY THROUGH EARLY ON SATURDAY. THIS WILL
RESULT IN A RATHER TIGHT PRESSURE GRADIENT...RATHER BRIEFLY THIS
EVENING INTO THE OVERNIGHT HOURS ACROSS THE HIGHER TERRAIN NEAR THE
VA BORDER.
ON SATURDAY THIS RIDGE WILL WEAKEN AS THE UPPER LEVEL TROUGH
APPROACHES THE LOWER OH VALLEY AS THE RIDGE RETREATS WEST AND
BUILDS TOWARD THE NORTHERN ROCKIES. A SFC COLD FRONT WILL ALSO
APPROACH THE LOWER OH VALLEY REGION AT THE END OF THE PERIOD.
ONCE EARLY MORNING VALLEY FOG DISSIPATES...A GENERAL WARMING TREND
IS EXPECTED THROUGH SATURDAY AS THE HIGH DEPARTS TO THE EAST. SOME
MOISTURE SHOULD BE DRAWN WEST AROUND THE DEPARTING HIGH LEADING TO
CU DEVELOPMENT ACROSS THE SOUTHEASTERN PART OF THE CWA FORM MIDDAY
INTO THE AFTERNOON. SOME OF THIS MAY BECOME DEEP ENOUGH FOR A FEW
ISOLATED SHOWERS BELOW THE MID LEVEL CAP. THE NAM IS GENERALLY THE
MOST AGGRESSIVE WITH THIS AMONG THE OPERATIONAL MODELS. THE END OF THE
THE 5Z HRRR RUN GENERALLY KEEPS THE ACTIVITY SOUTH OF THE REGION
THROUGH 20Z.
DIURNAL CU SHOULD DISSIPATE THIS EVENING...BUT MODELS KEEP THE LAYER
NEAR 800 TO 850 MB RATHER MOIST TONIGHT. SOME STRATOCU NEAR THE LEVEL
WILL BE POSSIBLE TONIGHT. PATCHY VALLEY FOG SHOULD STILL
DEVELOP...ESPECIALLY NORTH OF THE VA BORDER COUNTIES. MEANWHILE
DURING THE EVENING WHEN THE PRESSURE GRADIENT IS HIGHEST NEAR THE VA
BORDER AND A PERIOD OF SUSTAINED WINDS OF 10 TO 15 MPH IS
POSSIBLE...ESPECIALLY ACROSS THE EXPOSED RIDGETOPS SUCH AS THE
FLATWOODS AREA OF PIKE COUNTY...PORTIONS OF THE CREST OF PINE
MOUNTAINS AND BLACK MOUNTAINS. MOST LOCATIONS WILL EXPERIENCE LIGHTER
WINDS...WITH VALLEYS FURTHER NORTHWEST LIKELY DECOUPLED. HIGHER
ANTICIPATED DEWPOINTS...A LARGER PRESSURE GRADIENT AND THE POTENTIAL
FOR A FEW CLOUDS SHOULD BRING WARMER MIN T TONIGHT. SOUTH TO
EVENTUALLY SOUTHWEST FLOW WILL BRING WARMER AIR INTO THE REGION ON
SATURDAY. OUTSIDE OF THE HIGH TERRAIN...MAX TEMPS SHOULD REACH THE
LOW TO MID 80S. PRECIPITATION CHANCES ASSOCIATED WITH THE NEXT SYSTEM
SHOULD HOLD OFF UNTIL THE LONG TERM PERIOD.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 307 AM EDT FRI SEP 19 2014
THE EXTENDED PERIOD WILL START OFF ON 0Z SUNDAY WITH A DEEPENING
TROUGH IN THE LONGWAVE PATTERN ACROSS THE DAKOTAS. THIS WILL QUICKLY
MOVE SOUTHEASTWARD ACROSS THE UPPER GREAT LAKES BY SUNDAY
MORNING...QUICKLY PUSHING LOWERING HEIGHTS INTO THE OHIO RIVER
VALLEY THROUGHOUT THE DAY. AT THE SURFACE...A COLD FRONTAL BOUNDARY
WILL PUSH SE TOWARDS KY AS WELL...AND REACH THE OHIO RIVER JUST
AFTER 0Z SUNDAY. MODELS ARE FINALLY COMING INTO A MUCH BETTER
AGREEMENT FOR TIMING OF THE PRECIP ACCOMPANYING THE FRONT...WITH
POPS EXPECTED TO MOVE INTO THE NW PART OF THE CWA AS EARLY AS 12Z
SUNDAY...THEN QUICKLY SPREAD ACROSS THE REMAINING CWA DURING THE
AFTERNOON...BEFORE EXITING SE OF THE REGION BETWEEN 0 AND 6Z MONDAY.
LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL
INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...THOUGH IT HAS
IMPROVED SLIGHTLY FROM RUN TO RUN OVER THE LAST SEVERAL DAYS. WILL
CONTINUE TO SUPPORT IDEA FOR SOME SCATTERED THUNDERSTORMS DURING THE
DAY SUNDAY...WITH THE BEST CHANCE AROUND AND JUST AFTER 18Z...THEN
DROPPING OFF QUICKLY AS A LOW LEVEL INVERSION SETS UP AFTER 0Z
MONDAY AND WINDS QUICKLY TURN MORE NRLY BEHIND THE FRONTAL PASSAGE.
SOUTHERLY WINDS LEADING UP TO THIS FRONTAL PASSAGE WILL BRING ENOUGH
WAA TO KEEP TEMPS NEAR THE 80 DEGREE MARK FOR DURING THE DAY SUNDAY.
HOWEVER...AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY
WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING
PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO
THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL
PREVAIL. YET HIGH TEMPS ON MONDAY ARE ONLY EXPECTED TO MAKE IT INTO
THE LOW 70S THANKS TO THIS CANADIAN AIR MASS. TUESDAY WILL BE
SIMILAR...AS UPPER LEVEL RIDGING FINALLY MOVES IN OVERHEAD AND
LESSONS THE PRESSURE GRADIENT/STRONGEST NWRLY WINDS. AIRMASS
MODIFICATION WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE
REMAINDER OF THE EXTENDED...HOWEVER WE LIKELY WON/T SEE TEMPS HIT
ABOVE THE 80 DEGREE MARK UNTIL AT LEAST NEXT FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 145 AM EDT FRI SEP 19 2014
ASIDE FROM GENERALLY VALLEY FOG THAT MAY LIFT ONTO SOME OF THE
ADJACENT RIDGETOP LOCATIONS...ESPECIALLY IN THE BIG SANDY REGION.
SOME OF THIS FOG MAY BE PATCHY DENSE AND VI`S BELOW AIRPORT MI NS IS
POSSIBLE AT SJS. OTHERWISE...FOG SHOULD BE MVFR OR VFR AT THE TAF
SITES DURING THE 8Z TO 13Z PERIOD. OUTSIDE OF THIS VFR CONDITIONS AND
LIGHT WINDS WILL PREVAIL. A FEW SHOWERS MAY DEVELOP BETWEEN 16Z AND
22Z ACROSS THE FAR SOUTHEASTERN COUNTIES GENERALLY SOUTH AND EAST OF
A LOZ TO JKL TO SJS LINE. WHERE THESE SHOWERS OCCUR...BRIEF MVFR IS
POSSIBLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
520 AM EDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT FRI SEP 19 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A LOW AMPLITUDE PATTERN WITH A
MID/UPPER LEVEL RIDGE FROM THE PLAINS TOWARD THE UPPER MS VALLEY AND
A TROUGH FROM SRN SASK INTO THE NRN ROCKIES. AT THE SFC...SRLY FLOW
WAS INCREASING OVER THE UPPER MS VALLEY INTO THE WRN LAKES AS THE
PRES GRADIENT STRENGTHENS BETWEEN A TROUGH FROM MANITOBA INTO THE
NRN PLAINS AND HIGH PRES OVER QUEBEC. INCREASED LOW LEVEL MOISTURE
ADVECTION HAS ALSO BROUGHT SOME LOW CLOUDS INTO MUCH OF CNTRL WI AND
UPPER MI. SOME LIGHT SHOWERS OVER NR CNTRL MN WERE SUPPORTED BY
310K-315K ISENTROPIC ASCENT WITH FAVORABLE 850 MB THETA-E ADVECTION
ON 40-50 KNOT WINDS.
TODAY...RAIN SHOULD CONTINUE TO SPREAD TOWARD UPPER MI AS A WEAK
SHORTWAVE AND THE STRONGER 850 MB THETA-E ADVECTION MOVE IN. WITH
MODEL TRENDS HAVE SLOWING THE ARRIVAL OF THE PCPN INTO UPPER MI AND
THE PRESENCE OF A DRY 850-600 MB LAYER...RAIN CHANCES WILL INCREASE
INTO THE WEST HALF OF THE CWA MAINLY IN THE MID TO LATE AFTERNOON.
ONLY CHANCE FOR TSRA WAS MENTIONED OVER THE FAR WEST WHERE MUCAPE
VALUES CLIMB TO NEAR 800 J/KG. AS THE LOW CLOUDS MIX OUT TOWARD
AFTERNOON AND DAYTIME HEATING INCREASES...A BETTER PORTION OF THE
40-50 KNOT 900-850 MB WINDS MAY MIX TOWARD THE SFC. HOWEVER...THE
DEPTH OF THE MIXED LAYER SHOULD MAINLY ALLOW WIND GUSTS TO NEAR 30
KNOTS. HOWEVER...THERE MAY BE A PERIOD LATE THIS AFTERNOON OVER THE
EAST WHERE THE STRONG WINDS ABOVE THE LAKE MI MARINE LAYER ARE ABLE
TO MIX TOWARD THE SFC OVER THE EAST AND WINDS GUST INTO THE 30-40 MPH
RANGE FOR A TIME...ESPECIALLY FROM NEAR GRAND MARAIS TO NEWBERRY.
TONIGHT...SCT/NMRS SHOWERS AND A FEW THUNDERSTORMS WILL SPREAD
THROUGH THE CWA IN THE EVENING AS THE SFC AND MID LEVEL TROUGH APPROACH
AND THE AXIS OF HIGHER MOISTURE(PWAT TO 1.5 INCHES)/INSTABILITY
(MUCPAE TO NEAR 1K J/KG) MOVE IN. THE POTENTIAL FOR ELEVATED TSRA
REMAINS WITH 850 MB DEWPOINTS TO NEAR 14C.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI SEP 19 2014
NAM SHOWS A 500 MB TROUGH OVER THE UPPER GREAT LAKES 12Z SAT WITH
MORE UPPER LEVEL ENERGY DROPPING SOUTHEAST AND REINFORCING THE
TROUGH ON SUN AND INTO SUN NIGHT. DID NOT MAKE TOO MANY CHANGES TO
THE GOING FORECAST EXCEPT MOVED POPS A BIT FURTHER SOUTH LATER
SUNDAY AS A COLD FRONT MOVES THROUGH THE AREA. WENT WITH CHANCE POPS
MOSTLY FOR SAT INTO SUN...BUT HAVE SOME LIKELY POPS ACROSS THE
CENTRAL CWA SAT NIGHT AS NEXT ENERGY ARRIVES WITH MORE MOISTURE. DID
NOT CHANGE TEMPERATURES MUCH EITHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE WESTERN
U.S. 12Z MON WITH A TROUGH OVER THE EASTERN U.S. AND A TROUGH IN THE
DESERT SW. THE RIDGE MOVES INTO THE NORTHERN AND CENTRAL PLAINS 12Z
TUE WITH A TROUGH IN THE CENTRAL ROCKIES. THE RIDGE MOVES INTO THE
UPPER GREAT LAKES 12Z WED WITH THE TROUGH MOVING INTO THE NORTHERN
PLAINS. THE UPPER PATTERN DOES NOT CHANGE MUCH FOR 12Z THU. WHAT
THIS WILL MEAN IS A WARMING TREND IN THE EXTENDED WITH TEMPERATURES
GOING ABOVE NORMAL AND QUIET WEATHER FOR THE FORECAST PERIOD. WILL
ALSO REMAIN DRY FOR THE EXTENDED FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 121 AM EDT FRI SEP 19 2014
VEERING LOW-LEVEL WINDS IN RESPONSE TO DEPARTING SFC HIGH PRES WILL
BRING TRAJECTORIES OFF LAKE MICHIGAN FOR A TIME EARLY THIS MORNING.
THIS UPSLOPE FLOW OF LAKE MOISTENED AIR INTO COOLER AIR OVER UPPER
MI SHOULD RESULT IN STRATUS (IFR CIGS) SPREADING N TO KSAW TOWARD
DAYBREAK. THESE LOWER CLOUDS SHOULD LIFT AND SCATTER OUT MID MORNING
THRU EARLY AFTN AT KSAW. WHILE S WINDS ARE DOWNSLOPING AT KIWD...LOW
MVFR CIGS MAY DEVELOP THERE AS WELL TOWARD DAYBREAK AND THRU MID
MORNING. WITH FLOW UNDERGOING MORE SUBSTANTIAL DOWNSLOPING BEFORE
REACHING KCMX...OPTED TO MAINTAIN VFR CONDITIONS AT THAT TERMINAL.
OTHERWISE...TIGHTENING PRES GRADIENT AHEAD OF APPROACHING SFC TROF
WILL BRING GUSTY S WINDS TO ALL TERMINALS TODAY. FLOW IS ESPECIALLY
FAVORABLE FOR KSAW...AND EXPECT GUSTS TO 30KT OR PERHAPS HIGHER
THERE THIS AFTN. WITH UNCERTAIN COVERAGE OF SHRA AHEAD OF TROF...
ONLY VCSH WAS INCLUDED IN FCST AT KIWD/KCMX LATE IN THE AFTN/EARLY
EVENING. BETTER CHC OF SHRA AND PERHAPS A TSTM WILL ARRIVE AT
KCMX/KIWD DURING THE EVENING. CONDITIONS MAY FALL TO MVFR AT THAT
TIME.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT FRI SEP 19 2014
SOUTHERLY WINDS WILL INCREASE TODAY WITH LOW PRESSURE APPROACHING
FROM THE WEST AND HIGH PRESSURE JUST EAST OF LAKE SUPERIOR SHIFTING
EASTWARD. 20-30KT SOUTHERLY WINDS ARE EXPECTED ACROSS THE CENTRAL
AND EAST TODAY. A FEW GALES TO 35 KNOTS WILL BE POSSIBLE FOR THE
HIGHER PLATFORMS AND CLOSER TO THE UPPER MI SHORELINE. THE 20-30KT
SOUTH WINDS WILL GRADUALLY DIMINISH ACROSS THE EAST HALF OF THE LAKE
FRIDAY NIGHT THROUGH SATURDAY AS THE TROUGH MOVES ACROSS LAKE
SUPERIOR. EXPECT A PERIOD OF WESTERLY WINDS OF UP TO 20 KNOTS
SATURDAY AFTERNOON AND NW WINDS TO 20 KNOTS SUNDAY BEHIND THIS
TROUGH. WINDS WILL REMAIN UNDER 20 KNOTS THROUGH MUCH OF NEXT WEEK AS
A SERIES OF HIGH PRESSURE SYSTEMS MOVES OVER THE UPPER GREAT LAKES.
THE ONE EXCEPTION WILL BE THE CHANCE OF NORTH WINDS UP TO 25 KNOTS
MONDAY AFTERNOON AND EVENING BEHIND A QUICK-MOVING LOW PRESSURE
TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...
LONG TERM...07
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
339 AM MDT FRI SEP 19 2014
.SHORT TERM...VALID FOR TDY AND SAT...
AREAS OF SHOWERS AND THUNDERSTORMS WERE MOVING NE THROUGH MT IN A
POST-FRONTAL ENVIRONMENT AND AHEAD OF AN APPROACHING UPPER TROUGH.
MOST OF THE ACTIVITY WAS OVER SE MT EARLY THIS MORNING. THE
RIGHT-REAR QUADRANT OF AN UPPER JET WAS ALSO SUPPORTING THE
PRECIPITATION.
MODELS WERE SIMILAR IN MOVING THE UPPER TROUGH INTO E MT TODAY.
WHILE THE SSEO DID NOT HAVE A GOOD HANDLE ON THE PRECIPITATION
EARLY THIS MORNING...THE HRRR WAS DOING WELL AND MOVED EVERYTHING
OUT OF THE AREA AROUND 12Z. CONCERNED THIS MOVEMENT MAY BE A
LITTLE FAST GIVEN RADAR TRENDS...SO HAVE KEPT POPS OVER THE AREA
THIS MORNING...MAINLY E AND S OF KBIL. ALSO RAISED POPS TO CHANCE
IN SE MT. GIVEN STEEP MID AND UPPER LEVEL LAPSE RATES ON FORECAST
SOUNDINGS...WILL KEEP THUNDER IN THE FORECAST THIS MORNING. FOR
THE AFTERNOON...REMOVED POPS OVER KSHR DUE TO DOWNSLOPING AND KEPT
A LOW POP OVER THE NE BIG HORNS. MODELS AGREED THAT AIRMASS WILL
STABILIZE THIS AFTERNOON AS IT DRIES OUT. BASED ON MODEL
SOUNDINGS...WILL HAVE A BREEZY TO WINDY DAY OVER MOST AREAS WITH
THE FAST FLOW ALOFT. LOWERED TEMPERATURES A COUPLE OF DEGREES
BASED ON MIXING PROFILES AND WENT CLOSE TO CONSALL GUIDANCE.
WILL HAVE A FLAT NW FLOW OVER THE AREA TONIGHT...THEN UPPER
RIDGING AND DRY WEATHER BUILDS IN FOR THE REMAINDER OF THE
PERIOD. HAVE DRIED OUT THE EVENING WITH LIFT AND MOISTURE
CONTINUING TO EXIT THE REGION.
SAT WILL BE LESS WINDY THAN TODAY...AS FAST FLOW ALOFT SHIFTS E
WITH THE UPPER TROUGH. HOWEVER IT WILL STILL BE WINDY OVER PLACES
LIKE KBHK AND EKALAKA. EASTERLY WINDS ON SAT WILL INHIBIT MIXING
OVER THE AREA SO LOWERED TEMPERATURES SLIGHTLY TOWARD THE
SUPERBLEND GUIDANCE. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
MADE A FEW CHANGES TO THE EXTENDED FORECAST PACKAGE FOR A COUPLE
OF REASONS. THE FIRST CHANGE WAS TO RAISE POPS A BIT FOR THE
SUNDAY NIGHT THROUGH MONDAY NIGHT PERIOD. THIS IS IN RESPONSE TO
THE UPPER LOW CURRENTLY SITTING OVER CENTRAL CALIFORNIA. MODELS
PULL THIS SYSTEM INTO NORTHERN WYOMING AND SOUTHERN MONTANA SUNDAY
NIGHT AND EARLY MONDAY. MODELS HAVE TRENDED FARTHER NORTH WITH
THIS FEATURE AND BECAUSE OF SUCH PULL PRECIPITABLE WATERS AS HIGH
AS 1.5 INCHES INTO THE EASTERN HALF OF MONTANA...WHICH IS QUITE
HIGH FOR THIS TIME OF YEAR. JET FORCING WITH THE UPPER LOW IS
MINIMAL...BUT GIVEN THE AMOUNT OF PWAT AVAILABLE...SHOULD NOT BE
TERRIBLY DIFFICULT TO GET SHOWERS TO FORM.
THE SYSTEM KICKS OUT TUESDAY AFTERNOON AND NIGHT. THIS WILL DRY
THINGS OUT FROM WEST TO EAST. RIDGING FOLLOWS FOR WEDNESDAY. THIS
RIDING WILL QUICKLY BE REPLACED BY STRONG SOUTHWEST FLOW FOR A
STRONG DOWNSLOPE PATTERN. THIS IS THE SECOND CHANGE TO THE
FORECAST PACKAGE MADE...A CHANGE TO RAISE TEMPERATURES WEDNESDAY
INTO FRIDAY WITH THIS STRONG DOWNSLOPE PATTERN. WOULD EXPECT DRY
AIR TO GET PULLED UP FROM THE DESERT SOUTHWEST AND BECAUSE OF
THAT...MID 80S ARE QUITE POSSIBLE WEDNESDAY AND THURSDAY. THE FLY
IN THE OINTMENT OF WARMER TEMPERATURES COULD BE SOME CLOUD COVER
AS MID TO HIGH LEVEL MOISTURE TRIES TO INCREASE AHEAD OF AN
ADVANCING COLD FRONT. THIS FRONT APPROACHES THE WEST THURSDAY
EVENING AND WILL LEAD TO COOLER TEMPERATURES FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. TWH
&&
.AVIATION...
A FEW SHOWERS AND THUNDERSTORMS WILL LINGER OVER SOUTHEAST
MONTANA THIS MORNING. THIS PRECIPITATION WILL QUICKLY EXIT THE
AREA EARLY THIS MORNING. THE REST OF THE DAY WILL BE DRY AS WEST
TO NORTHWEST WINDS INCREASE. EXPECT GUSTS TO 20KTS ACROSS MUCH OF
THE AREA TODAY. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 078 052/074 049/076 053/076 054/080 054/082 054/080
1/B 00/U 00/U 13/T 31/B 11/U 11/B
LVM 075 043/076 041/076 047/074 049/078 048/080 049/078
1/N 10/U 00/U 23/T 21/B 11/B 12/T
HDN 080 050/076 045/078 052/078 052/080 052/084 052/082
2/T 00/U 00/U 13/T 31/B 11/U 11/B
MLS 080 051/075 045/076 052/079 054/078 053/083 053/084
2/T 00/U 00/U 02/T 21/B 11/U 11/B
4BQ 081 051/076 046/076 053/079 054/077 052/082 052/084
3/T 00/U 00/U 12/T 32/T 11/B 11/B
BHK 078 049/073 041/073 047/077 051/073 049/079 050/081
3/T 00/N 00/U 02/T 22/T 11/U 11/B
SHR 077 048/075 045/077 051/075 049/076 049/080 050/080
2/T 10/U 00/U 24/T 42/T 10/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
210 AM EDT FRI SEP 19 2014
.SYNOPSIS...
STRONG CANADIAN HIGH PRESSURE WILL BUILD ACROSS SOUTHERN QUEBEC
OVERNIGHT...THEN BUILD INTO NEW ENGLAND ON FRIDAY. FOLLOWING A
CHILLY MORNING...FRIDAY WILL BE MOSTLY SUNNY AND COOL. THEN AS
THE HIGH MOVES OFF THE COAST...ITS CLOCKWISE CIRCULATION WILL PUMP
NOTICEABLY WARMER AIR ACROSS OUR REGION FOR SATURDAY. A FRONTAL
SYSTEM WILL LIKELY GENERATE SOME SHOWERS FOR THE SECOND HALF OF
THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
TEMPERATURES OVERNIGHT WILL LARGELY DEPEND ON CLOUD COVER...WITH
SUB-FREEZING TEMPERATURES EXPECTED IN PORTIONS OF THE CWA. 11-3.9U
SATELLITE IMAGERY SHOWS PATCHY CLOUD COVER SOUTH OF LAKE
ONTARIO...WITH ANOTHER AREA OF CLOUDS ALONG A CONVERGENCE BOUNDARY
ON THE LAKE. CLOUDS ARE LIKELY TO EXPAND OVERNIGHT WITH THE 00Z BUF
SOUNDING SHOWING AN INVERSION DEVELOPING AT AROUND 900MB. CLOUDS
WILL SHIFT...HOWEVER...AS WINDS ALOFT VEER FROM NORTH TO EAST
OVERNIGHT. THIS WILL CAUSE THE CLOUDS ON LAKE ONTARIO TO MOVE ONTO
LAND OVERNIGHT...SIMILAR TO WHAT THE HRRR DEPICTS. THESE SUBTLETIES
MAKE THE TEMPERATURE FORECAST OVERNIGHT ESPECIALLY TRICKY.
HOWEVER...LINGERING CLOUD COVER AND DEW POINTS IN THE MID TO UPPER
40S ACROSS THE WESTERN TWO-THIRDS OF THE CWA SUGGEST TEMPERATURES
WILL LARGELY STAY ABOVE FREEZING OVERNIGHT WITH PERHAPS SOME PATCHY
FROST IN AREAS THAT CLEAR AND THE COOLEST OF VALLEYS. IN THESE
LOCATIONS...EXPECT INTERIOR LOCATIONS TO DROP INTO THE UPPER
30S...WITH LOWER 40S MORE COMMONPLACE ALONG THE LAKE SHORES...AND
WHERE CLOUD COVER PERSISTS. FOR THE NORTH COUNTRY...CLEARING SKIES
AND LIGHT SFC WINDS WILL PROMOTE FAVORABLE RADIATIONAL COOLING
CONDITIONS UP HERE. TEMPERATURES EAST OF LAKE ONTARIO WILL DROP INTO
UPPER 20S TO LOWER 30S WITH THE COOLEST LOCATIONS ACROSS THE TUG
HILL AND WESTERN ADIRONDACKS. WITH THIS IN MIND...FREEZE WARNING
REMAINS IN EFFECT FOR JEFFERSON/LEWIS COUNTIES...WITH A FROST
ADVISORY IN EFFECT FOR OSWEGO COUNTY.
HIGH PRESSURE WILL DRIFT SOUTHEAST ACROSS NEW ENGLAND FRIDAY
PROVIDING A NICE DAY...WITH MAINLY CLEAR TO PARTLY CLOUDY SKIES
ACROSS THE AREA. SOUTHEASTERLY FLOW ON THE BACK SIDE OF THE HIGH
WILL HELP BOOST HIGHS INTO THE LOW TO MID 60S ACROSS WESTERN NEW
YORK...WITH COOLER UPPER 50S TO AROUND 60 EAST OF LAKE ONTARIO WHERE
SOUTHERLY FLOW WILL NOT COMMENCE UNTIL A BIT LATER IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
THE STABLE ANTICYCLONE WILL RETREAT OFF THE NEW ENGLAND COAST FRIDAY
NIGHT AND SATURDAY. A SOUTHWESTERLY RETURN FLOW WILL DEVELOP AND
STRENGTHEN WITH TIME...AS THE PRESSURE GRADIENT INCREASES
SUBSTANTIALLY OVER PORTIONS OF THE EASTERN GREAT LAKES. THE WARM
ADVECTION PATTERN SHOULD REALLY BECOME PRONOUNCED DURING THIS TIME
WITH A POTENTIALLY VERY WARM DAY SATURDAY...ESPECIALLY AWAY FROM ANY
COOLING INFLUENCES DOWNWIND OF THE LAKES. FORECAST SOUNDINGS SUGGEST
A DECENT AMOUNT OF SUNSHINE...ESPECIALLY FROM MID DAY THROUGH EARLY
AFTERNOON. SUNSHINE COMBINED WITH THE FLOW OF INCOMING WARM AIR
SHOULD BOOST TEMPERATURES IN THE LOWER TO MID 70S...BY THIS MAY BE A
TAD CONSERVATIVE WITH 850 MB TEMPERATURES SURGING TO NEAR +14C
ESPECIALLY IF MORE SUNSHINE IS REALIZED. SOME OF THE FAVORED
DOWNSLOPE AREAS COULD GET INTO THE LOWER 80S. THE STRENGTHENING
GRADIENT FLOW WILL MAKE FOR A BREEZY DAY WITH GUSTS DOWNWIND OF THE
LAKES TO NEAR 40 MPH.
THE COLD FRONT IS STILL SLATED TO WORK ACROSS THE AREA DURING THE
DAY SUNDAY. THIS WILL BRING A PERIOD OF SHOWERS AND POSSIBLE THUNDER
STARTING LATE SATURDAY NIGHT AND LIKELY LASTING THROUGH MUCH OF
SUNDAY.
BY SUNDAY EVENING...THE SHOWER ACTIVITY SHOULD BE LARGELY TO OUR
EAST. A SWATH OF DRY SLOTTING/SUBSIDENCE WORKING IN BEHIND THE FRONT
SHOULD RESULT IN A BRIEF PERIOD OF MAINLY DRY WEATHER FOLLOWING THE
FRONT...BEFORE RENEWED SHOWER CHANCES DEVELOP WITH THE ARRIVAL OF
THE MAIN UPPER TROUGH AXIS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
UPPER LEVEL TROUGHING WILL LINGER ACROSS THE NORTHEAST CONUS MONDAY
AND TUESDAY. THE COOL CYCLONIC FLOW ACROSS THE REGION WILL LEAD TO
ANOTHER ROUND OF BELOW NORMAL TEMPERATURES...AS WELL AS THE
POTENTIAL FOR SOME LAKE EFFECT/INSTABILITY CLOUDS AND SHOWERS. AFTER
THAT...CONDITIONS SHOULD IMPROVE MARKEDLY BY MIDWEEK AS STRONG
RIDGING BUILDS ACROSS THE REGION AT ALL LEVELS. PLENTY OF ASSOCIATED
DRY AIR AND SUBSIDENCE/WARMING ALOFT SHOULD RESULT IN DRY WEATHER...
ALONG WITH TEMPERATURES MODERATING BACK CLOSER TO NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL DRIFT EAST ACROSS THE ST LAWRENCE VALLEY DURING
THE REMAINING OVERNIGHT HOURS...AND THIS WILL PROVIDE THE VAST
MAJORITY OF WESTERN AND NORTH CENTRAL NEW YORK WITH VFR CONDITIONS
AND LIGHT WINDS. THE EXCEPTION WILL BE ACROSS THE SRN TIER...AND
WITHIN A FEW MILES OF LAKE ONTARIO FROM KIAG AND KROC. FOR THE
LATTER...LAKE ENHANCED CLOUDS WILL REDUCE CIGS TO BETWEEN 800 AND
2500 FT AT TIMES...BUT A MORE WIDESPREAD AREA OF LOW STRATUS WILL BE
FOUND ACROSS THE SRN TIER. SEVERAL HOURS OF IFR CONDITIONS CAN BE
EXPECTED FOR BOTH KELZ AND KJHW.
AS WE PUSH PAST SUNRISE...FRIDAY WILL BE A PROBLEM FREE DAY FOR
AVIATORS AS WIDESPREAD SUBSIDENCE WILL PROVIDE LITTLE IN THE WAY OF
ANY CLOUD COVER AND WINDS WILL BE LIGHT.
FOR FRIDAY NIGHT...A STRENGTHENING LOW LEVEL JET WILL PRESENT THE
RISK FOR SOME LOW LEVEL WIND SHEAR. WILL MENTION THIS LATE IN THE
TAF PERIOD FOR THE FAR WESTERN SITES.
OUTLOOK...
FRIDAY NIGHT THROUGH SATURDAY...VFR.
SUNDAY...VFR/MVFR WITH SHOWERS BECOMING LIKELY.
MONDAY AND TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
HIGH PRESSURE WILL DRIFT EAST ACROSS THE ST LAWRENCE VALLEY DURING
THE REMAINDER OF THE OVERNIGHT. THIS WILL PRODUCE A LIGHT EASTERLY
FLOW ACROSS THE LOWER GREAT LAKES WITH NEGLIGIBLE WAVES. THE
EXCEPTION WILL BE OVER CANADIAN WATERS OF LK ONTARIO WHERE SOMEWHAT
STRONGER WINDS WILL PRODUCE WAVES THAT WILL APPROACH SMALL CRAFT
ADVISORY CRITERIA.
FOR FRIDAY...THE SFC WILL CROSS NEW ENGLAND. THIS WILL KEEP AN
EASTERLY FLOW IN PLACE FOR LAKES ERIE AND ONTARIO WITH WINDS AND
WAVES REMAINING WELL BELOW SCA CRITERIA.
WINDS WILL FRESHEN AND VEER TO THE SOUTH FRIDAY NIGHT AND SATURDAY
AS THE SFC HIGH WILL MOVE OFF THE COAST AND A FRONTAL SYSTEM WILL
START TO MAKE ITS WAY ACROSS THE UPPER GREAT LAKES. THIS COULD
RESULT IN SOME WIND BASED SMALL CRAFT ADVISORIES...WITH THE HIGHEST
WAVES BEING CONCENTRATED IN CANADIAN WATERS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR NYZ007-008.
FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NYZ006.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL/JM
NEAR TERM...APFFEL/JM/RSH
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...RSH
MARINE...RSH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 AM EDT FRI SEP 19 2014
.SYNOPSIS...HIGH PRESSURE CENTERED NORTHEAST OF THE GREAT LAKES WILL
EXTEND DOWN THROUGH VIRGINIA AND THE CAROLINAS THROUGH THE WEEKEND.
A COLD FRONT WILL APPROACH FROM THE NORTHWEST SUNDAY... THEN MOVE
SOUTHEAST THROUGH THE REGION SUNDAY NIGHT THROUGH EARLY MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 950 PM THURSDAY...
A FEW SHOWERS OVER THE WESTERN PIEDMONT EARLIER THIS AFTERNOON HAVE
BECOME PRIMARILY FOCUSED OVER THE SOUTHERN PIEDMONT THIS EVENING.
AIDED BY WEAK TROUGH ALOFT APPROACHING FROM THE NORTHWEST...THE
SHOWERS SHOULD CONTINUE TO PERCOLATE WITHIN A RIDGE OF THETA-E AND
SOME SHALLOW INSTABILITY...ABOUT 500 J/KG MUCAPE... BELOW 600MB.
NOCTURNAL COOLING WILL SLOWLY ERODE THE CAPE AND INCREASE THE
CINH...BUT THE HRRR SUGGESTS SHOWERS MAY CONTINUE WELL PAST
MIDNIGHT. THE FREEZING LEVEL ON THE KGSO RAOB WAS AROUND 10K
FT...SO CANNOT RULE OUT AN ISOLATED THUNDERSTORM...THOUGH THIS WILL
BECOME LESS LIKELY AS THE NIGHT WEARS ON. HAVE INCREASED POPS OVER
THE SOUTHERN PIEDMONT TO LIKELY FOR THE NEXT FEW HOURS WITH A TREND
DOWNWARD AFTER 06Z. LOWS UPPER 50S/LOWER 60S NORTHEAST TO MID 60S SOUTHWEST.
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 /06Z FRIDAY THROUGH TUESDAY/...
AS OF 200 AM FRIDAY...
VFR CONDITIONS WILL PREVAIL ACROSS CENTRAL NC THROUGH SATURDAY. A
WEAK SURFACE TROUGH IN THE VICINITY OF THE YADKIN RIVER VALLEY WILL
TRIGGER A FEW SHOWERS THROUGH 12Z IN VICINITY OF KINT AND KGSO.
THESE SHOWERS MAY CAUSE A BRIEF INSTANCE OF MVFR VISIBILITY.
LATER TODAY...HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM THE
NORTH. THE CIRCULATION AROUND THIS HIGH WILL RESULT IN AN LOW LEVEL
EASTERLY FLOW ACROSS NC. THIS FETCH OFF THE ATLANTIC WILL SPREAD LOW
LEVEL MOISTURE INTO OUR REGION. THIS WILL CAUSE A CLOUD DECK WITH
BASES 4500-6000FT WITH OVERCAST CONDITIONS HIGHLY PROBABLE OVER THE
PIEDMONT...AND SCATTER-BROKEN SKY CONDITIONS IN THE SANDHILLS AND
COASTAL PLAIN. AS THE HIGH STRENGTHENS FURTHER INTO CENTRAL NC LATE
TONIGHT INTO SATURDAY...DRIER AIR WILL INFILTRATE THE REGION...
DIMINISHING THE CLOUD COVERAGE.
A DEVELOPING AREA OF LOW PRESSURE OFFSHORE WILL SPREAD A VEIL OF
HIGH CLOUDS ACROSS THE EAST HALF OF NC LATE SATURDAY THROUGH EARLY
SUNDAY. A COLD FRONT WILL APPROACH FROM THE NW SUNDAY AND CROSS
CENTRAL NC SUNDAY NIGHT THROUGH EARLY MONDAY. A PERIOD OF MVFR
CEILINGS MAY OCCUR WITH THE FRONT. VFR CONDITIONS WILL RETURN MONDAY
INTO TUESDAY AS HIGH PRESSURE AND ASSOCIATED DRIER AIR MASS BUILDS
INTO OUR AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BLS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
339 AM CDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI SEP 19 2014
THIS MORNING A COLD FRONT WAS MOVING THROUGH WESTERN/CENTRAL NORTH
DAKOTA. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE
PRIMARILY FOCUSED ALONG THE FRONT AND PARALLEL/ON THE SOUTH SIDE
OF AN H300 JET. TO THE NORTH ISOLATED SHOWERS WERE ACROSS
SOUTHERN SASKATCHEWAN ASSOCIATED WITH THE SHORTWAVE TROUGH AT
H500. FOLLOWED THE HRRR AND NAM FOR POP GUIDANCE THIS MORNING.
BEST CHANCE FOR PRECIP WILL REMAIN ALONG THE SOUTH DAKOTA
BORDER...MAINLY SOUTH CENTRAL THIS AM. PRECIP ACROSS THE SOUTH
WILL GRADUALLY DIMINISH THIS MORNING AS SUBSIDENCE BEHIND THE
FRONT AND H300 JET TAKES HOLD. THEN THE EXIT REGION OF AN UPSTREAM
H300 JET WILL POSITION ITSELF TO SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS ALONG THE NORTHERN BORDER THIS AFTERNOON. IT WILL BE
A LITTLE E BREEZY WEST AFTER THIS AFTERNOON IN THE WAKE OF THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI SEP 19 2014
SOME SHOWERS/THUNDERSTORMS MAY LINGER INTO SATURDAY PRIMARILY OVER
NORTHERN INTO CENTRAL/EASTERN NORTH DAKOTA AS AREA REMAINS UNDER
CYCLONIC FLOW AND A POTENT SHORT WAVE MOVES THROUGH THE AREA. GUSTY
WINDS ARE EXPECTED TO DEVELOP THROUGHOUT THE AREA AS THE WAVE DIVES
THROUGH AND STRONGER WINDS MIX DOWN. WINDS WILL TAPER BY EVENING
WITH PRECIP ENDING AS UPPER RIDGE BUILDS OVER THE ROCKIES. QUIET
WEATHER EXPECTED TO START THE WEEK AS RIDGE AXIS WORKS EAST. BY
TUESDAY...A COMPACT UPPER LOW WORKS THROUGH THE RIDGE AND APPROACHES
THE REGION...SLOWLY WORKING OVER THE AREA THROUGH MID-WEEK. MODELS
STILL STRUGGLING SOME ON THE PLACEMENT OF THIS SYSTEM THOUGH AT THIS
TIME IT APPEARS THAT MOST OF THE PRECIP SHOULD STAY SOUTH OF THE
AREA SO WILL KEEP POPS ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 301 AM CDT FRI SEP 19 2014
A COLD FRONT WILL MOVE EAST ACROSS THE STATE TODAY AND WILL BE
THE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS MAINLY SOUTH
THIS MORNING. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED NORTH THIS AFTERNOON. VFR AT ALL TAF SITES. CURRENT
THREAT FOR THUNDERSTORMS IS TO UNCERTAIN TO INCLUDE IN TAFS AT
THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
LONG TERM...JJS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1251 AM CDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 1240 AM CDT FRI SEP 19 2014
00Z SOUNDING CONFIRMS MID LEVEL CAPPING. NORTH HALF OF THE STATE
FAIRLY DRY SO TRIMMED POPS. ALSO CAPPING SEEMS TO BE LIMITING
CONVECTION SO TRIMMED THUNDERSTORM CHANCES ALL AREAS EXCEPT SOUTH
CENTRAL THROUGH 12Z.
UPDATE
ISSUED AT 936 PM CDT THU SEP 18 2014
FORECAST REMAINS ON TRACK FOR THE LATE EVENING UPDATE. MAIN
MODIFICATIONS WERE TO POPS...TO ACCOUNT FOR THE EASTWARD
PROGRESSION OF CURRENT SHOWER ACTIVITY ACROSS THE SOUTH
CENTRAL...AND FOR A LARGE AREA OF SHOWERS/ISOLD THUNDER ACROSS
SOUTHEASTERN MONTANA MOVING EAST-NORTHEAST TOWARDS MY SOUTHWEST.
UPDATE
ISSUED AT 710 PM CDT THU SEP 18 2014
ROBUST CAPPING INVERSION KEEPING A LID ON STRONG CONVECTION EARLY
THIS EVENING ACROSS WESTERN AND CENTRAL NORTH DAKOTA DESPITE 1-2K
JOULES OF CAPE AND STRONG 0-6KM WIND SHEAR OF 40-45KTS. AN AREA OF
ELEVATED SHOWERS OVER THE SOUTHWESTERN QUARTER OF NORTH
DAKOTA...ASSOCIATED WITH A MID LEVEL IMPULSE...CONTINUES EASTWARD.
MODIFIED POPS BASED ON LATEST RADAR AND NEAR TERM HR MODEL
OUTPUT...TAKING THIS AREA OF PRECIPITATION EAST-NORTHEAST OVER THE
NEXT SEVERAL HOURS. GIVEN THE INSTABILITY PRESENT WILL MENTION AT
LEAST AN ISOLATED THUNDERSTORM CHANCE.
MID LEVEL SHORT WAVE APPROACHING THE INTERMOUNTAIN WEST AND
FORECAST TO MOVE EAST ACROSS THE NORTHERN PLAIN FRIDAY MORNING WILL
BRING A CONTINUED CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS THE LOCAL AREA OVERNIGHT TONIGHT THROUGH FRIDAY MORNING.
&&
.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 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1240 AM CDT FRI SEP 19 2014
AT MIDNIGHT CDT...SURFACE LOW PRESSURE WAS TRACKING ACROSS
SOUTHERN CANADA. A COLD FRONT ACROSS WESTERN NORTH DAKOTA WILL
MOVE EAST TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE
POSSIBLE SOUTH TONIGHT. DURING THE DAY FRIDAY THE CHANCE FOR
SHOWERS/THUNDERSTORMS WILL PRIMARILY BE NORTH OF LAKE SAKAKAWEA.
HOWEVER...TO MUCH UNCERTAINTY TO INCLUDE IN TAF FORECAST AT THIS
TIME. VFR AT ALL TAF SITES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...WAA
LONG TERM...JV
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
203 AM EDT FRI SEP 19 2014
.SYNOPSIS...
HIGH PRESSURE THROUGH SATURDAY. COLD FRONT SUNDAY. HIGH PRESSURE
NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
ADJUSTED POPS TO REFLECT ISOLATED SHOWERS COMING WWD OUT OF THE
MOUNTAINS LATE FRI AFTERNOON. FCST OTHERWISE ON TRACK.
PREV DISCN...
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 /TONIGHT 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 /05Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE SLOWLY DRIFTS AWAY TO THE NE THRU FRI BEFORE SLIDING
OFF THE E COAST THIS WEEKEND. IN THE NEAR TERM...THIS ALLOWS LOW
LEVEL FLOW TO VEER TO THE SE OVERNIGHT...BY ABOUT 09Z FRI. THIS
WILL ALLOW LOW CLOUDS TO INCREASE ALONG THE EASTERN SLOPES...WITH
MVFR CIGS 1 TO 2 KFT AT BKW FRI STARTING AROUND 09Z AND THEN
SCATTERING OUT FOR A TIME FRI EVENING.
DENSE VALLEY FOG IS LIKELY TO FORM ELSEWHERE...FIRST OVER THE TUG
FORK AND COAL FIELDS WHERE DEW POINTS ARE HIGHEST...AND LASTLY ALONG
RIVERS FARTHER N. MORNING CU IS LIKELY AS THE FOG DISSIPATES AFTER
SUNRISE...LEADING TO PATCHY MVFR CIGS 14-18Z FRI. VFR WILL FOLLOW
WITH AFTERNOON CUR AOA 4 KFT.
AFTER A CALM OVERNIGHT...SFC FLOW WILL BECOME LIGHT SE OVER THE
CENTRAL APPALACHIANS FRI AND LIGHT NE BECOMING LIGHT SE OVER THE
MIDDLE OHIO VALLEY. LIGHT TO MODERATE NE FLOW ALOFT WILL BECOME
LIGHT SE OVER THE CENTRAL APPALACHIANS LATE OVERNIGHT AND OVER THE
MIDDLE OHIO VALLEY DURING THE DAY FRI.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING LOWERING CEILING INTO SRN WV MOUNTAINS
WITH THE DEVELOPING EASTERLY UPSLOPE FLOW AROUND BKW MAY VARY.
TIMING AND DENSITY OF FOG MAY ALSO VARY INTO FRI MORNING.
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.
DATE FRI 09/19/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY M M L L L L L L M M M H
HTS CONSISTENCY H H H L L L L H H H H H
BKW CONSISTENCY H H H M M M M M M M M M
EKN CONSISTENCY H H H L L L L L M H M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z 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/TRM
SHORT TERM...RPY
LONG TERM...JSH
AVIATION...TRM
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1131 PM CDT THU SEP 18 2014
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
SOMEWHAT DRIER AIRMASS WILL WORK INTO MID STATE THRU 19/24Z...BUT STILL EXPECT
CKV/CSV TO EXPERIENCE MVFR FOG...TEMPO IFR FOG CSV...19/10Z-19/14Z. RIDGING
INFLUENCES SFC/ALOFT SHOULD PROVIDE FOR SCT DIURNAL CU DEVELOPMENT 19/15Z-
20/01Z...WITH VFR/SKC CONDITIONS THRU 20/06Z.
&&
.PREV DISCUSSION.../ISSUED 1031 PM CDT THU SEP 18 2014/
DISCUSSION...
IMPULSE CONTINUES TO WORK SOUTHWARD ACROSS WESTERN TN. LATEST IR
IMAGERY SHOWS A SLIGHT NORTHWARD JOG IN REGARD TO THE COOLER CLOUD
TOPS/ REFLECTIVITY LOOP ALSO SHOWS A FEW SHOWERS MAKING INTO OUR
FAR SW. WILL GO AHEAD AND UPDATE FCST AND INCLUDE A SLIGHT CHANCE
OF SHOWERS ACROSS OUR FAR SOUTHWEST. THE ACTIVITY SHOULD FINALLY
SLIP SOUTH OF OUR AREAS AFTER MIDNIGHT.
PREV DISCUSSION... /ISSUED 650 PM CDT THU SEP 18 2014/
DISCUSSION...
WILL REMOVE THE EVENING POPS ACROSS THE SOUTHWESTERN ZONES. THE
ACTIVITY IS WELL TO THE SOUTH OF THE AREA AND THE HRRR HAS
SIGNALED NO ADDITIONAL OVERNIGHT DEVELOPMENT. OTW...UPDATE WILL
REMOVE THE AFT WORDING. REMAINDER OF FCST IN GOOD SHAPE.
PREV DISCUSSION... /ISSUED 613 PM CDT THU SEP 18 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
MAYBE SOME ISO SHWRS W/SW OF TAF SITES THRU 19/03Z...BUT NO FORMATION/IMPACTS
AT TAF SITES EXPECTED. GENERALLY DRIER AIR IS EXPECTED TO WORK INTO MID STATE
THRU 19/24Z...BUT EXPECT CKV/CSV TO STILL EXPERIENCE MVFR FOG...TEMPO IFR FOG
CSV...19/10Z-19/14Z. RIDGING INFLUENCES SFC/ALOFT SHOULD PROVIDE FOR SOME
SCT DIURNAL CU DEVELOPMENT 19/15Z-19/24Z.
PREV DISCUSSION.../ISSUED 242 PM CDT THU SEP 18 2014/
DISCUSSION...ACTIVE WEATHER OCCURRING OVER THE SW CORNER OF
MIDDLE TENNESSEE, WHERE LOW-LEVEL MOISTURE AND INSTABILITY ARE
GREATEST. MAY SEE A FEW SHOWERS LINGER THERE INTO THE EARLY
EVENING. OTHERWISE, SURFACE HIGH PRESSURE CENTERED OVER THE GREAT
LAKES CONTINUES TO INFLUENCE OUR WEATHER. UPPER TROUGH IS NOW
SITUATED TO OUR EAST, WITH A NW FLOW ALOFT. AT THE SURFACE, LOOK
FOR TEMPERATURES TO CONTINUE WARMING AS WE HEAD INTO THE WEEKEND.
THE NEXT SURFACE FRONT WILL ENTER MIDDLE TENNESSEE FROM THE NW
SATURDAY NIGHT OR SUNDAY MORNING, WITH MAINLY SCATTERED POP`S WITH
THE FRONT. FORECAST SOUNDINGS DO SHOW SOME INSTABILITY WITH THIS
SYSTEM, SO WILL INCLUDE THUNDERSTORMS IN THE FORECAST. LOOK FOR
SLIGHTLY COOLER TEMPERATURES HEADING INTO NEXT WEEK WITH VERY
LITTLE CHANCE OF PRECIPITATION MONDAY THRU THURSDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
333 AM EDT FRI SEP 19 2014
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL SHIFT WEST ACROSS THE MOUNTAINS
TODAY AHEAD OF STRONG HIGH PRESSURE BUILDING IN FROM THE NORTH BY
THIS AFTERNOON. THE HIGH WILL WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE APPALACHIANS TONIGHT INTO SUNDAY KEEPING DRY
WEATHER IN PLACE. A COLD FRONT SHOULD CROSS THE AREA FROM THE
NORTHWEST LATER SUNDAY NIGHT INTO MONDAY FOLLOWED BY COOLER AND
DRIER WEATHER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT FRIDAY...
COMBINATION OF A WEAK SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL
THETA-E RIDGING EAST OF THE BLUE RIDGE CONTINUES TO LEAD TO ISOLATED
SLOW MOVING SHOWERS IN SPOTS EARLY THIS MORNING. EXPECT THIS TO PERSIST
A WHILE LONGER PER LATEST HRRR BEFORE THE DEVELOPING WEDGE STARTS TO
ENHANCE FROM NE TO SW BUT A BIT SLOWER THAN EARLIER THOUGHT. THIS
SHOULD START TO PRODUCE SOME SPOTTY -DZ ALONG THE EASTERN SLOPES AS
SHOWERS WANE PER INCREASING STABILITY BUT LOOKS LESS THAN PREVIOUS
GIVEN DRY AIR SAGGING IN FROM THE NORTH OFF MSAS. HOW FAST/DEEP ANY OF
THE LOW CLOUDS CAN BANK IN ALONG THE EASTERN SLOPES KEY TO CLOUDS/TEMPS
THIS AFTERNOON WITH MODELS NOW SLOWER IN INITIALLY PUSHING THE CAD
SOUTH AND WEST. THIS MAY LEAD TO AN AXIS OF MODEST INSTABILITY ESPCLY
ALONG THE I-77 CORRIDOR EARLY THIS AFTERNOON WHERE GUIDANCE REDEVELOPS
SHRA ALONG THE WESTWARD MOVING SURFACE TROUGH. SINCE THIS IN LINE WITH
CONSENSUS...BUMPED UP CHANCE POPS ACROSS NW NC...AND SW VA LATER WHILE
TRIMMING ANY -DZ/-RA TO ISOLATED -SHRA BLUE RIDGE...AND LITTLE MORE
THAN CLOUDS EAST-NE AS BUILDING HIGH PRESSURE START TO ENHANCE INLAND
FROM THE MID ATLANTIC COAST. ALSO INCLUDED AN ISOLATED -TSRA MENTION NW
NC RIDGES/FOOTHILLS WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
OTRW CLOUD COVER AND TEMPS THE MAIN ISSUES ESPCLY BLUE RIDGE WHERE
LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW DECK AND EASTERLY FLOW.
HOWEVER COULD ACTUALLY SEE READINGS PUSH INTO THE 70S FAR WEST GIVEN
THE SLOWER WEDGING...AS WELL AS OVER THE SOUTH/EAST IF CAN GET MORE
SUNNY BREAKS AS MOISTURE STARTS TO DECREASE FROM THE EAST LATE.
SURFACE RIDGING STRENGTHENS FROM THE NE OVERNIGHT HELPING PUSH THE
RESIDUAL AXIS OF MOISTURE FARTHER WEST WHICH SHOULD BRING AN END TO
POPS DURING THE EVENING. BANKED UP LOW LEVEL MOISTURE THOUGH LIKELY TO
REDEVELOP OR PERSIST BLUE RIDGE WHERE LOTS OF LOW CLOUDS/FOG POSSIBLE.
APPEARS AREAS OVER THE EAST/SE FROM HIGHWAY 29 EAST COULD SEE SOME
CLEARING AS MOISTURE GETS PINCHED FARTHER WEST AHEAD OF THE DRIER
EASTERLY FLOW. OTRW VARYING DEGREE OF CLOUDS FROM THE BLUE RIDGE WEST
WITH LOWS MAINLY IN THE 50S PER LATEST SIMILAR MAV/MET MOS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
THE HIGH PRESSURE CENTER THAT WAS OVER NEW ENGLAND WILL MOVE OUT
INTO THE ATLANTIC OVER THE WEEKEND. HOWEVER...THIS RIDGE WILL REMAIN
WEDGE BACK OVER THE MID ATLANTIC AND SOUTHEASTERN STATES INTO
SATURDAY NIGHT. A GULF STREAM DISTURBANCE WILL HELP KEEP THIS WEDGE
IN THE AREA AND ALSO PROVIDE SUBSIDENCE TO KEEP THE FORECAST AREA
DRY SATURDAY. THESE DISTURBANCE WILL HAVE MOST OF ITS RAIN FALLING
ON ITS EASTERN FLANK AS DRY AIR IS ENTRAINED INTO THE WESTERN SIDE.
THIS DISTURBANCE WILL TRACK TO THE NORTHEAST AND WILL REMAIN
OFFSHORE THROUGH THE WEEKEND.
MODELS HAVE SPED UP THE TIMING OF THE NEXT FRONTAL PASSAGE FROM
MONDAY TO SUNDAY. THIS FRONT STILL LOOKS LIKE A TYPICAL FALL FRONTAL
PASSAGE WITH RAIN FALLING ALONG WESTERN SLOPES...LOSING THEIR
INTENSITY MOVING TO THE BLUE RIDGE. THIS PRECIPITATION MAY THEN JUMP
THE FOOTHILLS AS A WEAK LINE OF CONVECTION DEVELOPS OVER THE
PIEDMONT WHERE A LEE TROUGH WILL RESIDE SUNDAY AFTERNOON. THE NAM
AND ECM LOOK SIMILAR WITH KEEPING BULK OF THE RAIN OVER THE
MOUNTAINS. THE GFS PROGRESSIVELY MOVES THE FRONT AND RAINFALL ACROSS
THE ENTIRE FORECAST AREA...DISREGARDING DOWNSLOPE. THE FORECAST DID
NOT DISCREDIT THE GFS...BUT MORE WEIGHT WAS PLACED WITH THE NAM/ECM
FOR SUNDAY.
SATURDAY TEMPERATURES WILL RUN WARMER THAN NORMAL WITH UPPER 70S TO
LOWER 80S. AREAS NOT SEEING RAIN UNTIL LATER IN THE DAY SUNDAY
SHOULD HAVE TEMPERATURES IN THE LOWER TO MID 80S. WESTERN SLOPES
SHOULD HAVE RAIN FALLING BY THE AFTERNOON AND MAY SEE HIGHS IN THE
MID 70S SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 200 PM EDT THURSDAY...
THIS PERIOD IS SHAPING UP TO BE DRY AND SEASONAL. ANOTHER SHORTWAVE
DROPS SOUTHEAST ACROSS THE TN VALLEY MONDAY AND COULD BRING ISOLATED
SHOWERS TO THE ENTIRE AREAS AS FLOW BACKS ALOFT SOME. THEN HIGH
PRESSURE ACROSS THE MIDWEST PUSHES EAST OVER THE MID ATLANTIC
TUE- WED. TEMPS BEHIND THIS SYSTEM EARLY NEXT WEEK WILL COOL DOWN
SOME...BUT NOT LOOKING AS CHILLY AS EARLIER THOUGHT...WITH 8H
TEMPS +10-12C.
HIGHS WILL RUN FROM THE 60S WEST TO 70S EAST...WITH LOWS MAINLY IN
THE 40S...WITH SOME 50S ACROSS THE PIEDMONT.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 100 AM EDT FRIDAY...
HIGH END STRATO-CU ALONG WITH WIDESPREAD MID DECK PREVAIL ACROSS
MUCH OF THE REGION ATTM WITH WEAK MOISTURE CONVERGENCE BEING FED
VIA RESIDUAL LOW LEVEL THETA-E RIDGING JUST EAST OF THE BLUE
RIDGE. ACTUAL COOL FRONT THAT WILL SET A MORE EASTERLY REGIME INTO
MOTION OVERNIGHT STILL LAGGING TO THE NORTH SO IFFY AS TO HOW MUCH
CIGS WILL FALL BY DAYBREAK GIVEN CURRENT CANOPY. THIS SIMILAR TO
EARLIER IN THE WEEK WITH LOW LEVEL MOISTURE STUCK TO THE SOUTH
AND BOUNDARY LAYER DRY ADVECTION WINNING OUT ACROSS THE REGION.
THIS SHOWN IN DIFFERING MODEL SOLUTIONS FROM IFR IN STRATUS/DZ/FOG
TO VFR OUTSIDE OF PATCHY FOG LATE. FOR NOW WILL CONTINUE GOING
TRENDS OF LOWERING CIGS THROUGH MVFR TO IFR IN SPOTS BY DAWN
ESPCLY BLUE RIDGE WHILE SLOWING DOWN THE ONSET A BIT. MAY END UP
WITH A RIBBON OF ONLY IFR/LIFR AT KBCB/KROA AND MAINLY MVFR TO
BRIEF IFR ELSW BUT LOW CONFIDENCE. SPOTTY SHOWERS REMAIN ACROSS
THE FAR NE NEAR KLYH AND JUST SW OF KDAN SO WILL INCLUDE A VCSH
MENTION IN THESE SPOTS EARLY ON AND KEEP SOME -DZ MENTION ALONG
THE BLUE RIDGE.
ONCE CIGS DO LOWER EARLY FRIDAY...EXPECT LITTLE CHANGE DURING THE
MORNING WITH SOME IMPROVEMENT IN THE AFTERNOON AS CIGS TEND TO
LIFT SOME ESPCLY AWAY FROM THE BLUE RIDGE. OTRW OVERALL LITTLE
IMPROVEMENT IS EXPECTED WITH CIGS REMAINING MVFR MOST SITES ALL
DAY...BUT VSBYS SHOULD BE MOSTLY VFR AFT 15Z/11AM. WINDS BECOMING
ENE- ESE OVERNIGHT AT SPEEDS OF 5-7KTS...INCREASING TO 7-10KTS AFT
14Z/10AM FRI. SOME POTENTIAL FOR LOW END GUSTS IN USUALLY FAVORED
SOUTHEAST WIND AREAS...SUCH AS BLF...AFT 15Z FRI.
CIGS MAY LOWER AGAIN FRIDAY EVENING PENDING DEGREE OF
EROSION/COVERAGE HEADING INTO LATE FRIDAY AFTERNOON SO TRENDING
BACK TOWARD MVFR FROM THE BLUE RIDGE EAST EARLY FRIDAY NIGHT.
ANOTHER ROUND OF LOW CIGS IN FOG AND STRATUS LIKELY LATER FRIDAY
NIGHT INTO EARLY SATURDAY WITH SOME ADDED PATCHY -DZ POSSIBLE.
EXTENDED AVIATION DISCUSSION...
WEDGE SHOULD ERODE FAIRLY QUICKLY SATURDAY IN RESPONSE TO AN
UPSTREAM TROUGH. SOME LOW CLOUDS MAY LINGER THROUGH THE MORNING
ALONG WITH PATCHY FOG...BUT OVERALL VFR CONDITIONS EXPECTED SAT. A
FRONTAL SYSTEM WILL APPROACH SUN WITH -SHRA AND PERHAPS AN ISOLD
TSRA WEST OF THE ALLEGHANY FRONT. INSTABILITY IS QUITE LIMITED AND
SO IS DEEP MOISTURE. WITH A POSSIBLE TROPICAL SYSTEM DEVELOPING
OFF THE COAST AT THE SAME TIME...WE MAY BE IN A STRONG SUBSIDENCE
AREA AND SEE LITTLE MORE THAN -SHRA OR SPRINKLES EAST OF THE
ALLEGHANY FRONT. EXPECT MOSTLY VFR-PERIODS OF MVFR CIGS SUN-EARLY MON
AS THE TROUGH MOVES THROUGH. HIGH PRESSURE BUILDS IN FOR THE FIRST
HALF OF NEXT WEEK WITH DRY NW FLOW. THUS...EXPECT MOSTLY VFR
CONDITIONS THROUGH THE PERIOD WITH LOCAL EARLY MORNING MVFR-IFR
FOG CONDITIONS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...WP
AVIATION...JH/KK/RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
219 AM CDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 219 AM CDT FRI SEP 19 2014
FORECAST CONCERNS INCLUDE PRECIPITATION CHANCES THROUGH
TONIGHT...SEVERE WEATHER POTENTIAL TONIGHT...AND WINDS THIS
AFTERNOON.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE CENTRAL PLAINS WHILE A FAST SEMI-ZONAL FLOW
WAS PRESENT ALONG THE U.S./CANADIAN BORDER. WITHIN THIS FLOW...A
SHORTWAVE TROUGH WAS OVER SOUTHERN SASKATCHEWAN AND ADJACENT
MONTANA. THIS TROUGH HAS BEEN RESPONSIBLE FOR... 1. PLENTY OF
MID/HIGH CLOUDS DOWNSTREAM OVER THE DAKOTAS...SOME OF WHICH WERE
PRODUCING SHOWERS AND A FEW THUNDERSTORMS. 2. PULLING MORE HUMID AIR
THROUGH THE DAKOTAS ON A 20-40 KT JET AT 925MB WITH SURFACE
DEWPOINTS IN THE 60S...AS WELL AS PRECIPITABLE WATER OF 1-1.5
INCHES. FINALLY 3...DEVELOPING AN UNSEASONABLY WARM...CAPPED AIRMASS
OVER SOUTH DAKOTA CHARACTERIZED BY 850MB TEMPS OF 18-24C AND 700MB
TEMPS OF 10-13C. OVER THE FORECAST AREA...MUCH COOLER AND DRIER AIR
EXISTS WITH 850MB TEMPS AROUND 10C AND PRECIPITABLE WATER AROUND 0.5
INCH. A WARM FRONT SEPARATES THE DIVISION OF AIRMASSES OVER WESTERN
MN...WHICH ISENTROPIC LIFT/MID-LEVEL MOISTURE TRANSPORT INTO THE
FRONT HAS LED TO MID CLOUDS IN MN. NOTHING YET FALLING OUT OF
THESE...THOUGH.
MODELS ARE IN AGREEMENT TRACKING THE SHORTWAVE TROUGH OVER
SASKATCHEWAN AND MONTANA INTO THE DAKOTAS BY 00Z. WHAT THIS DOES IS
HELP CONTINUE A WARM ADVECTION REGIME DOWNSTREAM INTO THE FORECAST
AREA. THE BIG PLUME OF WARM 700MB AND 850MB AIR OVER SOUTH DAKOTA
STREAMS EAST-NORTHEAST ACROSS THE FORECAST AREA...AS WELL AS OVER
CENTRAL MN AND NORTHWEST WI...EFFECTIVELY PUTTING A NICE CAP IN
PLACE. PRIOR TO THIS CAP ARRIVING THIS AFTERNOON...A FEW DAYS AGO IT
APPEARED THAT THE ISENTROPIC LIFT AND MID-LEVEL MOISTURE TRANSPORT
WOULD BE ENOUGH TO INITIATE CONVECTION. HOWEVER...THAT DOES NOT
APPEAR TO BE THE CASE ANYMORE WITH MOST MODELS SUGGESTING A DRY DAY
TODAY. HAVE STILL LEFT SOME LOW CHANCES IN TAYLOR AND CLARK COUNTIES
FOR THE LATE AFTERNOON...DUE TO ACTIVITY OVER NORTH DAKOTA PROGGED
TO MARCH EAST ACROSS NORTHERN WI. NOW THE 19.00Z GFS DOES PRODUCE
SOME PRECIP FROM EAU TO LSE DURING THE EARLY AFTERNOON HOURS...BUT
APPEARS TO BE THE LONE MODEL OUT. SOUNDINGS TOO FROM THE GFS AT LSE
LOOK ODD FOR PRODUCING RAIN...HAVING JUST SOME SMALL LAYER OF
SATURATION BELOW THE CAP.
PRESSURE GRADIENT EXPECTED TO BE QUITE TIGHT TODAY OVER THE FORECAST
AREA AHEAD OF A COLD FRONT CROSSING THE DAKOTAS. WITH 850MB WINDS
INCREASING THIS AFTERNOON TO 35-50 KT SOUTHEAST TO NORTHWEST ACROSS
THE FORECAST AREA...AND DAYTIME MIXING...WE COULD SEE GUSTS UPWARDS
OF 25-35 KT. HIGHEST GUSTS ARE ANTICIPATED OVER HIGHER TERRAIN OF
SOUTHEAST MN. THESE WOULD BE JUST UNDER ADVISORY CRITERIA. REGARDING
THE AFOREMENTIONED MIXING...PERIODS OF SUN PLUS 925MB TEMPS CLIMBING
TO 16-20C BY 00Z...MOST LOCATIONS OUTSIDE OF TAYLOR/CLARK SHOULD SEE
HIGHS IN THE 70S.
FOR TONIGHT...MODELS BRING THE SHORTWAVE TROUGH INTO MN AND NORTHERN
WI...DRAGGING THE SURFACE COLD FRONT THROUGH THE NORTHWEST HALF OF
THE FORECAST AREA BY 12Z SAT. ALL MODELS SUGGEST THAT THE DPVA AHEAD
OF THE TROUGH WILL HELP COOL THE CAP...AND FORCE SOME CONVECTION TO
DEVELOP. APPEARS MUCH OF THE CONVECTION WILL BE ROOTED ABOVE THE
BOUNDARY LAYER WITH PARCELS BEING LIFTED BETWEEN 850-900MB...OR
ABOUT 1 KM ABOVE THE GROUND. CAPE LIFTED FROM THIS LEVEL RANGES FROM
1500-2000 J/KG WHILE THE 1-6KM SHEAR IS ONLY 10-15 KT. THAT SHEAR IS
CERTAINLY UNFAVORABLE FOR SEVERE. IF FOR SOME REASON THE PARCELS CAN
GET ROOTED BELOW 1 KM...THE 0-3KM SHEAR IS 35-40 KT...MUCH MORE
FAVORABLE. GIVEN THAT EQUILIBRIUM LEVELS ARE UP NEAR 40000 FT...CAN
NOT RULE OUT AN ISOLATED SEVERE STORM CAPABLE OF HAIL/WIND...WHICH
LOOKS MOST LIKELY SOMETIME IN THE LATE EVENING OR EARLY MORNING.
CONSIDERED RAISING PRECIPITATION CHANCES UP TO 60...BUT BOTH THE
19.00Z NSSL WRF-ARW AND NCEP HIRES-ARW SUGGEST ANYWHERE FROM
ISOLATED-SCATTERED COVERAGE. APPEARS THE LACK OF DECENT CONVERGENCE
BETWEEN 900-700MB IS THE CAUSE. ALL MODELS DO AGREE THAT THE BULK OF
THE CONVECTION SHOULD BE EXITING THE AREA BY 12Z. IT SHOULD
GENERALLY BE A WARM NIGHT UNTIL THE FRONTAL PASSAGE DUE TO A BREEZY
WIND AND HIGHER DEWPOINTS. AFTER FROPA...IT LOOKS LIKE A LOW STRATUS
DECK MAY FORM AS MODELS SUGGEST A SHALLOW COOL AIRMASS MOVING IN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 219 AM CDT FRI SEP 19 2014
COMPARED TO THE SHORT TERM PERIOD...GENERALLY QUIET WEATHER
DOMINATES THE LONG TERM. THERE ARE A FEW TIME PERIODS TO FOCUS ON.
GENERAL MODELS CONSENSUS IS FOR THE SHORTWAVE TROUGH TO MOVE
INTO/OVER THE FORECAST AREA BY 18Z SATURDAY...PUSHING THE COLD FRONT
ALL THE WAY THROUGH. IT APPEARS ANY CONVECTION RE-FIRING ALONG THE
COLD FRONT ON SATURDAY WILL OCCUR SOUTHEAST OF THE FORECAST AREA.
STILL MAINTAINED SOME LOW PRECIPITATION CHANCES OVER THE SOUTHEAST
HALF OF THE FORECAST AREA IN THE MORNING...THOUGH...AS WE WAIT FOR
THE SHORTWAVE TROUGH TO FULLY MOVE IN. THEN THERE SHOULD BE A
BREAK...AHEAD OF A FAIRLY POTENT SHORTWAVE DROPPING IN ON THE BACK
SIDE OF THE SHORTWAVE TROUGH OVER MN BY 00Z SUNDAY. THIS SHORTWAVE
DIVES THROUGH THE FORECAST AREA SATURDAY NIGHT. THE POTENT NATURE
COULD BE ENOUGH TO BRING SOME SHOWERS ACROSS THE FORECAST AREA...BUT
THERE IS SOME UNCERTAINTY ON MOISTURE AVAILABILITY. A LOT OF MODELS
HAVE ANY PRECIPITATION WITH THE SHORTWAVE DIMINISHING BEFORE IT
COMES INTO THE FORECAST AREA...OR MAYBE HOLDING ONTO IT FOR I-94.
SOME COLD POOL SHOWERS...ENHANCED BY A SECONDARY COLD FRONT DROPPING
THROUGH THE FORECAST AREA...COULD OCCUR ON SUNDAY ALONG AND NORTH OF
I-94. OTHERWISE...SUNDAY LOOKS SIGNIFICANTLY COOLER COMPARED TO
SATURDAY WITH 925MB TEMPS FALLING FROM 18-21C AT 00Z SUNDAY TO 11-
13C AT 18Z SUNDAY.
SUNDAY NIGHT THROUGH TUESDAY CONTINUES TO BE DOMINATED BY HIGH
PRESSURE AT THE SURFACE...WHILE VERY STRONG UPPER RIDGING MARCHES
FROM THE NORTHWESTERN U.S. INTO THE REGION. THIS SETUP WILL FAVOR A
COOL NIGHT WITH POTENTIAL FOR VALLEY FOG SUNDAY NIGHT...FOLLOWED BY
GRADUAL AIRMASS MODIFICATION AND WARMING THROUGH TUESDAY.
FOR WEDNESDAY AND THURSDAY...AN UPPER TROUGH CURRENTLY SITTING OFF
THE CALIFORNIA COAST IS PROGGED TO LIFT THROUGH THE REGION. TOUGH TO
SAY HOW MUCH MOISTURE THIS FEATURE WILL HAVE WITH IT AT THIS
TIME...AND IF ITS TRACK ENDS UP GOING THROUGH THE REGION OR STAYING
OFF TO THE WEST. THEREFORE...FOR NOW THE FORECAST JUST HAS SOME LOW
PRECIPITATION CHANCES WITH IT. TEMPERATURES COULD GET KNOCKED DOWN A
LITTLE BIT WITH THIS UPPER TROUGH MOVING THROUGH.
BEYOND THURSDAY...GOOD MODEL RUN TO RUN CONSISTENCY EXISTS THAT
THE UPPER TROUGH WILL LIFT OUT OF THE REGION...IN RESPONSE TO STRONG
UPPER RIDGING BUILDS OVER THE EASTERN TWO THIRDS OF THE COUNTRY
GOING INTO NEXT WEEKEND. THIS UPPER RIDGING SHOULD BRING DRY
CONDITIONS ALONG WITH ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1132 PM CDT THU SEP 18 2014
PRESSURE GRADIENT IS BEGINNING TO TIGHTEN ACROSS THE AREA WITH THE
WINDS STARTING TO INCREASE. EXPECT TO SEE SUSTAINED SOUTH WINDS
FOR THE REMAINDER OF THE NIGHT AROUND 10 KNOTS AND WITH THE
INCREASE ALOFT JUST ABOVE THE SURFACE...STILL EXPECTING TOO MUCH
MIXING TO ALLOW ANY FOG TO FORM. THE 19.00Z NAM IS NOT QUITE AS
STRONG WITH THE WINDS ALOFT SO SHOULD HAVE ANY LOW LEVEL WIND
SHEAR CONCERNS. HOWEVER...ONCE THE LOW LEVEL INVERSION DISSIPATES
FRIDAY MORNING...THE MIXING WILL ALLOW THE STRONG WINDS ALOFT TO
REACH THE SURFACE AND STILL EXPECT SOME GUSTS TO AROUND 30 KNOTS
FOR BOTH SITES DURING THE AFTERNOON. AS THE CAP BUILDS OVER THE
AREA FRIDAY AHEAD OF THE APPROACHING COLD FRONT EXPECT ANY MID
LEVEL SHOWERS THAT MAY FORM TO REMAIN WELL NORTH OF BOTH TAF
SITES. AS THE SHORT WAVE TROUGH APPROACHES FRIDAY EVENING ALONG
THE COLD FRONT...THE CAP MAY WEAKEN ENOUGH TO ALLOW SOME
CONVECTION TO FORM ALONG THE FRONT. WILL INCLUDE A VCTS FOR KRST
FOR LATE FRIDAY EVENING BUT KEEP KLSE DRY AT THIS POINT.
CONFIDENCE IS NOT HIGH ENOUGH ON THE TIMING FOR KLSE TO INCLUDE
THUNDER IN THE FORECAST AT THIS POINT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
445 AM PDT FRI SEP 19 2014
UPDATED AVIATION SECTION
.SYNOPSIS...
WEAK UPPER LEVEL LOW PRESSURE WILL BRING BELOW NORMAL TEMPERATURES
TO MUCH OF THE REGION THROUGH THE WEEKEND. TEMPERATURES WILL LIKELY
WARM TO NEAR NORMAL EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
HIGH PRESSURE BRIEFLY RETURNS. ANOTHER TROUGH OF LOW PRESSURE MAY
BRING A COOLING TREND FOR THE SECOND HALF OF NEXT WEEK.
&&
.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED
PLENTY OF LOW LEVEL MOISTURE LINGERING ACROSS COAST AND VALLEYS N OF
POINT CONCEPTION...WHILE LOW CLOUDS WERE MORE RANDOM IN NATURE FOR
AREAS SOUTH OF POINT CONCEPTION. LOW CLOUDS SHOULD FILL IN ACROSS
COAST AND VALLEYS OF LOS ANGELES...VENTURA AND SANTA BARBARA
COUNTIES BY DAWN. THERE WILL BE ENOUGH LOW LEVEL LIFT TO CAUSE SOME
PATCHY DRIZZLE TO OCCUR JUST ABOUT ANYWHERE WEST OF THE MOUNTAINS
THIS MORNING. LATEST ACARS SOUNDING NEAR LAX SHOWED A VERY WEAK
INVERSION IN PLACE WHICH MAKES SENSE WHY CLOUDS ARE NOT MORE UNIFORM
S OF POINT CONCEPTION THIS MORNING. WIND PATTERNS ARE INTERESTING
THIS MORNING. OVER THE COASTAL AREAS INTO LA COUNTY THE FLOW IS
MOSTLY CYCLONIC NW BECOMING SW OVER LA COUNTY. HOWEVER...NORTHERLY
WINDS WERE OCCURRING OVER THE MOUNTAINS AND SAN JOAQUIN VALLEY. THIS
NORTHERLY FLOW WAS CAUSING ADDITIONAL CLOUDS TO PILE UP ALONG THE
NORTHERN SLOPES OF THE LOCAL MOUNTAINS THIS MORNING INCLUDING THE
I-5 CORRIDOR.
SYNOPTICALLY...A CLOSED 578 DM UPPER LOW CURRENTLY OFF THE CENTRAL
COAST WILL DRIFT SLOWLY SOUTH JUST WEST OF POINT CONCEPTION BY THIS
AFTERNOON. THE PROXIMITY OF THE UPPER LOW WILL ALLOW FAVORABLE COOL
CYCLONIC FLOW OVER MOST OF LOS ANGELES...VENTURA AND SANTA BARBARA
COUNTIES TODAY. THERE IS NOT MUCH IN THE WAY OF MOISTURE ASSOCIATED
WITH THE UPPER LOW...BUT THERE WILL BE PLENTY LOW CLOUDS LINGERING
ACROSS THE COAST AND VALLEYS THROUGH THIS MORNING AND INTO THE
AFTERNOON ACROSS MOST COASTAL AREAS. RAP AND NAM-WRF MODELS
INDICATED THAT THERE WOULD BE ENOUGH INSTABILITY AND LIMITED MID
LEVEL MOISTURE TO WARRANT A SLIGHT CHANCE FOR SHOWERS OR
THUNDERSTORMS TO DEVELOP OVER THE VENTURA COUNTY MOUNTAINS AS WELL
AS PORTIONS OF THE SANTA BARBARA COUNTY MOUNTAINS THIS AFTERNOON AND
EVENING HOURS. TEMPERATURES WILL CONTINUE TO TREND COOLER THROUGH
SATURDAY AS THE UPPER LOW MOVES DIRECTLY OVER SBA/VENTURA
COUNTIES SATURDAY AFTERNOON. THERE IS NOT MUCH DIFFLUENCE ASSOCIATED
WITH THE UPPER LOW FOR SATURDAY AND MODELS WERE NOT PICKING UP ON
ANY ADDITIONAL MOISTURE OR CONVECTIVE PARAMETERS ACROSS THE LOCAL
MOUNTAINS. WILL LET LATER SHIFTS LOOK CLOSER TO SEE IF SLIGHT CHANCE
POPS WILL BE NEEDED FOR SAT IN THE LOCAL MTNS ONCE AGAIN.EXPECT HIGH
TEMPS TO BE NEAR OR JUST BELOW NORMAL TODAY AND SATURDAY.
BY SUNDAY...THE UPPER LOW WILL FILL IN AND MOVE NE INTO NEVADA
ALLOWING HEIGHTS AND THICKNESS LVLS TO RISE. THERE WILL BE NIGHT
THROUGH MORNING LOW CLOUDS BUT A QUICKER BURNOFF AND HIGH TEMPS WILL
BE A FEW DEGREES HIGHER...ESPECIALLY ACROSS INTERIOR
LOCATIONS...WITH WARMEST VALLEY LOCATIONS IN THE MID 80S...AND MID
TO UPPER 70S ALONG THE COAST.
.LONG TERM (MON-THU)...BOTH GFS AND ECMWF STAY IN PRETTY GOOD
AGREEMENT OVER THE LONG TERM PERIOD. A WEAK RIDGE WILL BEGIN TO
BUILD OVER BAJA CALIFORNIA WHILE MUCH OF NORTHERN CALIFORNIA REMAIN
UNDER A BROAD UPPER TROUGH THROUGH WED. EXPECT NIGHT THROUGH MORNING
LOW CLOUDS FOR COASTAL AREAS AND POSSIBLY SOME COASTAL VALLEYS
THROUGH WED MORNING. TEMPS WILL CONTINUE TO REBOUND MONDAY AND
TUESDAY WITH HIGHS REACHING THE LOWER 90S ACROSS WARMEST VALLEY
LOCATIONS. FOR WED AND THU...A BROAD UPPER TROUGH WILL BEGIN TO DIG
FARTHER SOUTH. THE GFS IS SHOWING A SHARPER TROUGH WHICH WOULD MEAN
MORE SIGNIFICANT COOLING BY THURSDAY...WHERE THE EUROPEAN MODEL IS
LESS PRONOUNCED. AT THIS POINT HAVE TRENDED HIGH TEMPS DOWN SLIGHTLY
FOR WED...WITH A FEW MORE DEGREES OF COOLING FOR THURSDAY TO
SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...19/1145Z.
DEEP MARINE LAYER IN PLACE WITH VERY WEAK INVERSION. WIDESPREAD MVFR
CIGS WILL LIKELY SCATTER OUT LATE THIS MORNING OR EARLY THIS
AFTERNOON...BUT THERE IS A CHANCE THAT CIGS WILL LINGER. EXPECT
WDSPRD STRATUS WITH MOSTLY MVFR CONDS AGAIN TONIGHT/SAT MORNING.
KLAX...MODERATE CONFIDENCE IN 12Z TAF. THERE IS A 30 PERCENT CHANCE
THAT CIGS WILL LINGER THRU THE DAY.
KBUR...MODERATE TO HIGH CONFIDENCE IN 12Z TAF. THERE IS A 20 PERCENT
CHANCE THAT CIGS WILL LINGER THRU THE DAY.
&&
.MARINE...19/300 AM
GOOD CONFIDENCE IN SCA CONDITIONS ACROSS THE SRN TWO THIRDS OF THE
OUTER WATERS THRU LATE TONIGHT...THOUGH WINDS MAY DROP BELOW
ADVISORY LEVELS FOR A FEW HOURS FROM MID MORNING THRU EARLY
AFTERNOON. THERE IS A 20-30 PERCENT CHANCE OF SCA LEVEL WINDS ACRS
WRN SECTIONS OF THE SBA CHANNEL LATE THIS AFTERNOON THRU THE EVENING.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
&&
$$
PUBLIC...KAPLAN
AVIATION/MARINE...DB
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1013 AM EDT FRI SEP 19 2014
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE ACROSS TO THE NORTH OF THE REGION TODAY AND
THEN SHIFTS OFFSHORE TONIGHT. A COLD FRONT WILL CROSS THE AREA
SUNDAY NIGHT INTO MONDAY. HIGH PRESSURE BUILDS IN FROM THE WEST
MONDAY AND PERSISTS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
13Z SURFACE ANALYSIS SHOWS A 1031 MB SFC HIGH CENTERED JUST NORTH OF
MONTREAL. HIGH PRESSURE CONTINUES TO NOSE DOWN THE EASTERN SEABOARD,
RESULTING IN A COOL NORTHEAST BREEZE THIS MORNING. THIS HIGH WILL
SHIFT SOUTHEASTWARD TODAY. LOW-LEVEL WINDS AROUND THE HIGH WILL VEER
THROUGHOUT THE DAY AS THE HIGH BUILDS TOWARD THE GULF OF MAINE THIS
AFTERNOON.
THE DEVELOPMENT OF STRATOCU CAN ALREADY BE SEEN NEAR THE NJ (AND TO
A LESSER EXTENT THE DE COAST) ON THE MID MORNING VISIBLE SATELLITE,
WHICH IS A PROXY FOR WHERE THE MARINE LAYER HAS BECOME ESTABLISHED
AND FOR THE LEADING EDGE OF THE STRONGER ONSHORE FLOW. BASED ON
LATEST VISIBLE SATELLITE IMAGERY AND RAP GUIDANCE (WHICH HAS
INITIALIZED WELL WITH LOW-LEVEL RH FIELD), MARINE-LAYER STRATOCU
EXPECTED TO ADVECT INLAND AS FAR WEST AS EASTERN PA TODAY. MIXING
SHOULD BE DEEP ENOUGH ON LAND TO SEE SOME BREAKS IN THE CLOUDS THIS
AFTERNOON AWAY FROM THE COAST.
RETURN FLOW DEVELOPING AROUND THE WESTERN PERIPHERY OF THE RIDGE
WILL PRODUCE WEAK ISENTROPIC LIFT OVER THE CWA LATE THIS AFTERNOON.
KEPT MEASURABLE PRECIP OUT OF THE FORECAST, BUT ADDED IN SPRINKLES
FOR EXTREME SOUTHERN NJ AND THE DELMARVA. THIS PORTION OF THE AREA
SHOULD BE LOCATED CLOSER TO THE GREATER LIFT AND MOISTURE RETURN.
MADE MINOR ADJUSTMENTS TO TEMP FORECAST BASED ON SKY COVER UPDATES.
MAX TEMPS RANGE FROM THE MID/UPPER 60S IN THE HIGHER ELEVATIONS AND
ALONG THE CENTRAL NJ COAST TO LOW/MID 70S SOUTHEAST PA AND THE
DELMARVA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
THE PERIOD BEGINS AND ENDS WITH AN ONSHORE FLOW. MODELS, INCLUDING
STAT GUIDANCE, HAVE CLOUDS ON THE INCREASE OVERNIGHT. THIS LOOKS
REASONABLE. IN RESPONSE TO THE DEEPENING LOW LEVEL MOISTURE, SOME
DRIZZLE IS POSSIBLE ACROSS OUR UPSLOPE ZONES WEST OF THE DELAWARE
VALLEY AND LOCALES ALONG THE COAST.
OVERNIGHT LOWS WILL DROP INTO THE UPPER 40S ACROSS OUT NORTHWEST
ZONES AND INTO THE MID TO UPPER 50S ACROSS THE COASTAL PLAIN.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
SATURDAY...SATURDAY LOOKS TO BE A PRETTY DRY DAY ACROSS THE REGION.
ALTHOUGH THERE WILL BE A MID LEVEL SHORTWAVE ROTATING THROUGH, THERE
IS NOT AN ABUNDANCE OF MOISTURE AROUND AND IT DOESN`T LOOK LIKE WE
WILL SEE MUCH IN THE WAY OF SHOWERS ACROSS THE AREA.
RETURN FLOW AROUND THE DEPARTING HIGH PRESSURE WILL HELP TO BRING IN
SOME MOISTER AND WARMER AIR. MAX TEMPS WILL RISE INTO THE MID TO
UPPER 70S ACROSS MUCH OF THE REGION. TEMPS OVERNIGHT WILL DROP INTO
THE UPPER 50S TO LOWER 60S.
SUNDAY...A COLD FRONT WILL GRADUALLY PUSH TOWARDS THE REGION ON
SUNDAY. HOWEVER, THE FRONTS PROGRESS APPEARS TO BE ON THE SLOW SIDE
AND IT LIKELY WONT REACH THE REGION UNTIL LATER IN THE DAY AND WON`T
FULLY MOVE OFFSHORE UNTIL LATE SUNDAY NIGHT/EARLY MONDAY MORNING. WE
HAVE ADDED A SLIGHT CHANCE OF THUNDER INTO THE FORECAST FOR SUNDAY
AFTERNOON/NIGHT. THE INSTABILITY ISN`T TERRIBLY STRONG BUT IT IS
AVAILABLE AND WE CAN`T RULE OUT A RUMBLE OR TWO ACROSS THE REGION.
BEST CHANCES LOOK TO BE OUT AHEAD OF THE FRONT AND CHANCES WILL
DIMINISH AS WE HEAD INTO SUNDAY NIGHT.
SUNDAY WILL BE THE WARMEST DAY OF THE WEEK ACROSS OUR AREA AS MAX
TEMPS REACH INTO THE 80S. BEHIND THE FRONT, TEMPERATURES WILL DROP
AND OVERNIGHT LOWS WILL DROP INTO THE 50S. WHERE SKIES START TO
CLEAR A BIT MORE, ESPECIALLY ACROSS THE NORTHWESTERN AREAS, WE COULD
SEE TEMPS DROP DOWN INTO THE UPPER 40S.
MONDAY...THE COLD FRONT PUSHES TO THE SOUTH OF THE AREA AND WE
SHOULD SEE SOME DRIER AND COOLER AIR MOVING IN ON THE NORTHWEST
FLOW. ANY LINGERING SHOWERS WILL CLEAR QUICKLY. MAX TEMPS WILL BE
AROUND 8-12 DEGREES COOLER ACROSS THE REGION. MOST AREAS WILL SEE
MAX TEMPS IN THE UPPER 60S TO LOWER 70S. OVERNIGHT LOWS WILL FEEL
CONSIDERABLY COLDER, WITH MOST PLACE DROPPING DOWN INTO THE 40S,
WITH SOME 50S POSSIBLE CLOSER TO THE COAST.
TUESDAY THRU THURSDAY...HIGH PRESSURE STARTS TO BUILD IN FROM THE
WEST ON TUESDAY. THE HIGH GRADUALLY SHIFTS TO THE NORTH OF THE
REGION AND SLOWLY MOVES ACROSS AND INTO NEW ENGLAND THROUGH THE
WEEK. THIS WILL KEEP THE WEATHER PRETTY DRY WITH A SOUTH TO
SOUTHEAST FLOW ACROSS THE REGION. A MID LEVEL SHORTWAVE WILL ROTATE
THROUGH THE AREA ON TUESDAY AND MAY SPARK OFF A FEW SHOWERS. FOR
NOW, WE HAVE KEPT THE FORECAST DRY AS THE SOUNDINGS LOOK PRETTY
DRY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
NORTHEAST WINDS THIS MORNING 10-15 KT WILL OCCASIONALLY GUST NEAR 20
KT FROM THE PHILLY TERMINALS SOUTH AND EAST. GRADIENT FLOW WEAKENS A
BIT THIS AFTN AS WINDS VEER OUT OF THE EAST. MARINE AIRMASS WILL
MOVE INLAND AS WELL WITH A PERIOD OF MVFR CIGS POSSIBLE. NEEDED TO
UPDATE 12Z TAFS FOR A FEW LOCATIONS AS STRATOCU HAS DEVELOPED SOONER
THAN PREVIOUSLY FORECAST. EXPECT IMPROVEMENT TO VFR DURING THE AFTN
AT ALL TERMINALS EXCEPT ACY, WHERE MARINE AIR IS MORE ESTABLISHED.
TONIGHT...WITH THE ONSHORE FLOW, LOWERING AND THICKENING CLOUDS CAN
BE EXPECTED. FOR NOW WE`LL DROP THINGS DOWN TO MVFR, 1500-2500 FT.
SOME DRIZZLE IS POSSIBLE, ESPECIALLY ACROSS KABE, KRDG, KACY, AND
KMIV. WINDS WILL REMAIN OUT OF THE EAST, BUT LIGHTEN UP A BIT.
OUTLOOK...
SATURDAY THROUGH SATURDAY NIGHT...MAINLY VFR CONDITIONS EXPECTED.
STRATUS/FOG DEVELOPMENT POSSIBLE SATURDAY NIGHT WITH LOWER CEILINGS
AND VISIBILITIES INTO SUNDAY MORNING.
SUNDAY THROUGH SUNDAY NIGHT...FOG/STRATUS POSSIBLE EARLY...THEN
MAINLY VFR CONDITIONS EXPECTED MUCH OF THE DAY. LOWER VISIBILITIES
AND CEILINGS POSSIBLE THROUGH THE AFTERNOON/EVENING IN
SHOWERS/THUNDERSTORMS IN ADVANCE OF AN APPROACHING COLD FRONT. THE
FRONT WILL MOVE THROUGH LATE SUNDAY INTO MONDAY.
MONDAY THROUGH TUESDAY...MAINLY VFR CONDITIONS EXPECTED. NORTHWEST
WINDS AROUND 10 TO 15 KNOTS ON MONDAY...LESS WINDY ON TUESDAY.
&&
.MARINE...
BOTH BUOY 44065 AND 44025 ARE FINALLY BACK IN SERVICE!
NORTHEAST WIND SURGE HAS ADVANCED SOUTHWARD ALONG THE COAST THIS
MORNING, REACHING ATLANTIC CITY BY 10 AM WITH GUSTS AROUND 25 KT.
HAVE EXPANDED SCA TO INCLUDE LITTLE EGG INLET TO GREAT EGG
INLET. SCA ALREADY IN EFFECT TODAY FOR MARINE ZONES FARTHER
NORTH. WINDS WILL LIKELY SUBSIDE A BIT TO BELOW SCA THRESHOLD
DURING THE AFTN BUT SEAS BUILDING TO 5 FT WILL RESULT IN A
CONTINUATION OF SCA CONDITIONS THRU THE REMAINDER OF THE DAY.
TONIGHT...ALSO MADE SOME CHANGES TO THE GRIDS. WE`VE BACKED OFF OF
HEADLINES AND HAVE DELAYED THE SCA FOR THE SOUTHERN WATERS. ACROSS
THE NORTHERN WATERS, WE`LL HAVE THE SCA RUN THROUGH ABOUT 06Z. LOOKS
LIKE A LOWER END SCA WITH WINDS TOPPING OUT AROUND 20 KT AND SEAS 5
FT.
OUTLOOK...
SATURDAY...SEAS LOOK TO BE ELEVATED HEADING THROUGH
THE DAY ON SATURDAY AND WILL GRADUALLY START TO SUBSIDE INTO
SATURDAY EVENING. THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED
THROUGH LATE SATURDAY AFTERNOON AT THIS TIME. IT MAY NEED TO BE
EXTENDED INTO SATURDAY EVENING FOR A PERIOD UNTIL SEAS FALL BELOW
5 FEET. WINDS LOOK TO REMAIN BELOW 25 KNOTS ACROSS THE WATERS.
SUNDAY...WINDS AND WAVES ARE EXPECTED TO REMAIN BELOW ADVISORY
CRITERIA THROUGH SUNDAY.
SUNDAY NIGHT THROUGH MONDAY...A COLD FRONT WILL CROSS THE AREA
WATERS LATE SUNDAY INTO EARLY MONDAY. SHOWERS AND THUNDERSTORMS WILL
ACCOMPANY THE FRONTAL PASSAGE. IN ADDITION, WINDS AND WAVES WILL
START TO INCREASE AND A SMALL CRAFT ADVISORY MAY BE NEEDED.
TUESDAY...SUB-ADVISORY CONDITIONS ARE EXPECTED AS HIGH PRESSURE
MOVES INTO THE REGION.
&&
.RIP CURRENTS...
WITH LONG PERIOD SWELLS STILL PRESENT TODAY, A TIGHTENING GRADIENT
AND INCREASING WAVE HEIGHTS, IN HOUSE GUIDANCE CONTINUES TO SUGGEST
A MODERATE RISK TODAY FOR NJ AND DE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ452.
SMALL CRAFT ADVISORY FROM 2 AM TO 6 PM EDT SATURDAY FOR
ANZ453>455.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ450-451.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...KLEIN
SHORT TERM...KRUZDLO
LONG TERM...MEOLA
AVIATION...KLEIN/KRUZDLO/MEOLA
MARINE...KLEIN/KRUZDLO/MEOLA
RIP CURRENTS...KRUZDLO
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1110 AM EDT FRI SEP 19 2014
.DISCUSSION...
MORNING CAPE SOUNDING SHOWS SIGNIFICANT MOISTENING HAS OCCURRED IN
THE MID AND UPPER LEVELS WITH NOTICEABLY DRIER AIR STILL IN PLACE
BETWEEN 5K AND 10K FT...FOR NOW. THE 13KM RUC SHOWS LARGE AREA OF
UPPER DIFFLUENT FLOW AT 250 MB SUPPORTING CONVECTION OVER THE
EASTERN GULF OF MEXICO. THIS UPPER SUPPORT WILL OVERSPREAD THE AREA
TODAY AND PRODUCE A LARGE AREA OF MOSTLY LIGHT RAIN ACROSS NORTHERN
SECTIONS AS TOP-DOWN MOISTENING CONTINUES. A BETTER CHANCE FOR DEEP
CONVECTION (THUNDER) WILL OCCUR OVER SOUTHERN SECTIONS WHERE SOME
HEATING HAS TAKEN PLACE THIS MORNING THROUGH A THINNER CANOPY OF
CIRRUS. BUT CONTINUED MOISTENING OF THE AIRMASS COMBINED WITH FORCED
ASCENT WILL PRODUCE INCREASED MULTI LAYERED CLOUDINESS...BECOMING
OVERCAST EVEN ACROSS THE SOUTH. THIS WILL HAVE AN IMPACT ON MAX
TEMPS WHICH SHOULD HOLD IN THE MID 80S MOST AREAS.
AS LIGHT RAIN BREAKS OUT ACROSS NORTHERN SECTIONS AND PUSHES
EASTWARD...ISOLATED SHOWERS WILL PUSH WEST FROM THE ATLC AND ONSHORE
IN AN INCREASING LOW LEVEL E/NE FLOW ON THE NORTH SIDE OF TROUGH
AXIS STRETCHING FROM SOUTH FL ACROSS THE NORTHERN BAHAMAS.
TONIGHT...AS THE SFC LOW BEGINS TO TAKE SHAPE JUST OFF THE SEFL
COAST... CONTINUED ASCENT ALOFT...INCREASING LOW LEVEL
CYCLONIC/CONVGT FLOW NEAR/ALONG THE COAST COUPLED WITH WRAP BACK
MOISTURE AND THE NOCTURNAL INCREASE IN MARINE INSTABILITY SHOULD
RESULT IN DECENT CHC FOR POPS...ESPECIALLY ALONG COASTAL AREAS WELL
INTO THE OVERNIGHT HOURS. THERE MAY BE ONE OR MORE BANDS OF RAIN
THAT DEVELOP FROM THE ATLC ACROSS PORTIONS OF THE COAST THAT
PROVIDES PERIODS OF (LOCALLY) HEAVY RAIN. VERY DIFFICULT TO PINPOINT
WHERE THAT COULD OCCUR BUT SOMEWHERE ALONG THE VOLUSIA AND/OR
BREVARD COASTS APPEARS FAVORED.
&&
.AVIATION...
INCREASING THREAT FOR SHOWERS THROUGHOUT THE DAY WITH TS COVERAGE
LIKELY TO BE ISOLD DUE TO THICKENING CLOUD COVER LIMITING SFC
HEATING ESP NORTHERN TERMINALS. 12Z TAF PACKAGE DID NOT INCLUDE VSBY
RESTRICTIONS IN WHAT WILL BE MOSTLY LIGHT RAIN AND PSBLY SOME
HEAVIER EMBEDDED CONVECTION MAINLY MLB SOUTHWARD. WILL INDICATE
PREVAILING MVFR CIGS AT COASTAL TERMINALS DAB/MLB/VRB TONIGHT.
&&
.MARINE...
NO SIGNIFICANT CHANGES TO CURRENT COASTAL WATERS FORECAST.
DECAYING LONG PD SWELL (NOW DOWN TO 10-11 SEC) FROM VERY DISTANT
T.S. EDOUARD WILL GIVE WAY TO INCREASING WIND CHOP ON NORTH SIDE OF
DEVELOPING SFC TROUGH/LOW OFF OUR SE COAST THROUGH TONIGHT. E/NE
FLOW NEAR 15 KNOTS WILL BUILD SEAS TO 4FT OFFSHORE TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 83 72 86 71 / 60 50 50 30
MCO 85 71 87 70 / 60 40 50 30
MLB 84 74 85 71 / 70 50 60 30
VRB 84 72 87 70 / 70 50 60 30
LEE 84 70 88 71 / 60 40 40 30
SFB 85 70 88 72 / 60 40 50 30
ORL 85 71 87 72 / 60 40 50 30
FPR 85 73 86 69 / 70 50 60 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
KELLY/WEITLICH
AREA FORECAST DISCUSSION
NWS JACKSON KY
955 AM EDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 955 AM EDT FRI SEP 19 2014
ALL IS QUIET THIS MORNING WITH A BEAUTIFUL MORNING ONGOING. LAST OF
THE FOG SHOULD BURN OFF OVER THE NEXT HOUR OR SO. NO SIGNIFICANT
CHANGES EXCEPT TO REFINE PRECIPITATION CHANCES BASED ON LATEST HI RES
MODEL GUIDANCE. THIS WAS ONLY TO TRIM SOME AREAS OUT OF THE THREAT
FOR SHOWERS THIS AFTERNOON. OTHERWISE...CURRENT FORECAST SEEMS ON
TRACK.
UPDATE ISSUED AT 740 AM EDT FRI SEP 19 2014
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT SATELLITE IMAGERY AND
OBSERVATIONS. THIS LED TO VERY LITTLE CHANGE...JUST A FRESHENING UP
OF THE HOURLY TEMP AND DEWPOINT CURVES OVER THE NEXT FEW HOURS.
VALLEY FOG ACROSS THE SOUTHERN AND SOUTHEASTERN COUNTIES HAS LIKELY
ALREADY BEGUN TO LIFT AND SHOULD DISSIPATE BY AROUND 9 AM. THE 6Z
GFS AND NAM SUGGESTED THE POTENTIAL FOR A STRAY SHOWER ACROSS THE
SOUTHEASTERN NEAR THE VA OR WV BORDER. THE MODEL CONSENSUS SEEMS TO
INDICATE THE HIGHEST CHANCES FOR AN ISOLATED SHOWER FROM HARLAN
COUNTY NORTHEAST TO PIKE COUNTY AND POSSIBLY INTO THE NEXT TIER OF
COUNTIES TO THE NORTH.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM EDT FRI SEP 19 2014
THROUGH TONIGHT...UPPER LEVEL RIDGING CURRENTLY CENTERED OVER THE
PLAINS STATES WILL BUILD EAST INTO THE LOWER OH VALLEY REGION TODAY
AND INTO TONIGHT. MEANWHILE A WEAK UPPER LOW/TROUGH OF LOW PRESSURE
WILL REMAIN ACROSS THE SOUTHEASTERN CONUS. FURTHER TO THE NORTHWEST A
SERIES OF SHORTWAVES IS EXPECTED TO LEAD TO AN UPPER LEVEL TROUGH
WORKING INTO THE GREAT LAKES REGION BY THE END OF THE PERIOD. AT THE
SFC...HIGH PRESSURE CURRENTLY CENTERED OVER QUEBEC AND EXTENDING
SOUTHWEST INTO THE OH VALLEY REGION WILL MOVE EAST SOUTHEAST TO NEAR
CAPE COD THIS EVENING AND THEN OFF THE NORTHEAST US COAST TONIGHT AND
INTO SATURDAY. AS THE HIGH MOVES EAST...AN INVERTED TROUGH IS
EXPECTED TO DEVELOP ACROSS THE REGION TODAY AND THEN SHIFT WEST AND
WEAKEN TONIGHT. TO THE EAST OF THE CREST OF THE APPALACHIANS...A
RIDGE OF HIGH PRESSURE IS EXPECTED TO EXTEND SOUTHWEST FROM THIS SFC
HIGH INTO THE APPALACHIANS GENERALLY ALONG OR JUST TO THE EAST OF THE
BLUE RIDGE MOUNTAINS LATER TODAY THROUGH EARLY ON SATURDAY. THIS WILL
RESULT IN A RATHER TIGHT PRESSURE GRADIENT...RATHER BRIEFLY THIS
EVENING INTO THE OVERNIGHT HOURS ACROSS THE HIGHER TERRAIN NEAR THE
VA BORDER.
ON SATURDAY THIS RIDGE WILL WEAKEN AS THE UPPER LEVEL TROUGH
APPROACHES THE LOWER OH VALLEY AS THE RIDGE RETREATS WEST AND
BUILDS TOWARD THE NORTHERN ROCKIES. A SFC COLD FRONT WILL ALSO
APPROACH THE LOWER OH VALLEY REGION AT THE END OF THE PERIOD.
ONCE EARLY MORNING VALLEY FOG DISSIPATES...A GENERAL WARMING TREND
IS EXPECTED THROUGH SATURDAY AS THE HIGH DEPARTS TO THE EAST. SOME
MOISTURE SHOULD BE DRAWN WEST AROUND THE DEPARTING HIGH LEADING TO
CU DEVELOPMENT ACROSS THE SOUTHEASTERN PART OF THE CWA FORM MIDDAY
INTO THE AFTERNOON. SOME OF THIS MAY BECOME DEEP ENOUGH FOR A FEW
ISOLATED SHOWERS BELOW THE MID LEVEL CAP. THE NAM IS GENERALLY THE
MOST AGGRESSIVE WITH THIS AMONG THE OPERATIONAL MODELS. THE END OF THE
THE 5Z HRRR RUN GENERALLY KEEPS THE ACTIVITY SOUTH OF THE REGION
THROUGH 20Z.
DIURNAL CU SHOULD DISSIPATE THIS EVENING...BUT MODELS KEEP THE LAYER
NEAR 800 TO 850 MB RATHER MOIST TONIGHT. SOME STRATOCU NEAR THE LEVEL
WILL BE POSSIBLE TONIGHT. PATCHY VALLEY FOG SHOULD STILL
DEVELOP...ESPECIALLY NORTH OF THE VA BORDER COUNTIES. MEANWHILE
DURING THE EVENING WHEN THE PRESSURE GRADIENT IS HIGHEST NEAR THE VA
BORDER AND A PERIOD OF SUSTAINED WINDS OF 10 TO 15 MPH IS
POSSIBLE...ESPECIALLY ACROSS THE EXPOSED RIDGETOPS SUCH AS THE
FLATWOODS AREA OF PIKE COUNTY...PORTIONS OF THE CREST OF PINE
MOUNTAINS AND BLACK MOUNTAINS. MOST LOCATIONS WILL EXPERIENCE LIGHTER
WINDS...WITH VALLEYS FURTHER NORTHWEST LIKELY DECOUPLED. HIGHER
ANTICIPATED DEWPOINTS...A LARGER PRESSURE GRADIENT AND THE POTENTIAL
FOR A FEW CLOUDS SHOULD BRING WARMER MIN T TONIGHT. SOUTH TO
EVENTUALLY SOUTHWEST FLOW WILL BRING WARMER AIR INTO THE REGION ON
SATURDAY. OUTSIDE OF THE HIGH TERRAIN...MAX TEMPS SHOULD REACH THE
LOW TO MID 80S. PRECIPITATION CHANCES ASSOCIATED WITH THE NEXT SYSTEM
SHOULD HOLD OFF UNTIL THE LONG TERM PERIOD.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 307 AM EDT FRI SEP 19 2014
THE EXTENDED PERIOD WILL START OFF ON 0Z SUNDAY WITH A DEEPENING
TROUGH IN THE LONGWAVE PATTERN ACROSS THE DAKOTAS. THIS WILL QUICKLY
MOVE SOUTHEASTWARD ACROSS THE UPPER GREAT LAKES BY SUNDAY
MORNING...QUICKLY PUSHING LOWERING HEIGHTS INTO THE OHIO RIVER
VALLEY THROUGHOUT THE DAY. AT THE SURFACE...A COLD FRONTAL BOUNDARY
WILL PUSH SE TOWARDS KY AS WELL...AND REACH THE OHIO RIVER JUST
AFTER 0Z SUNDAY. MODELS ARE FINALLY COMING INTO A MUCH BETTER
AGREEMENT FOR TIMING OF THE PRECIP ACCOMPANYING THE FRONT...WITH
POPS EXPECTED TO MOVE INTO THE NW PART OF THE CWA AS EARLY AS 12Z
SUNDAY...THEN QUICKLY SPREAD ACROSS THE REMAINING CWA DURING THE
AFTERNOON...BEFORE EXITING SE OF THE REGION BETWEEN 0 AND 6Z MONDAY.
LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL
INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...THOUGH IT HAS
IMPROVED SLIGHTLY FROM RUN TO RUN OVER THE LAST SEVERAL DAYS. WILL
CONTINUE TO SUPPORT IDEA FOR SOME SCATTERED THUNDERSTORMS DURING THE
DAY SUNDAY...WITH THE BEST CHANCE AROUND AND JUST AFTER 18Z...THEN
DROPPING OFF QUICKLY AS A LOW LEVEL INVERSION SETS UP AFTER 0Z
MONDAY AND WINDS QUICKLY TURN MORE NRLY BEHIND THE FRONTAL PASSAGE.
SOUTHERLY WINDS LEADING UP TO THIS FRONTAL PASSAGE WILL BRING ENOUGH
WAA TO KEEP TEMPS NEAR THE 80 DEGREE MARK FOR DURING THE DAY SUNDAY.
HOWEVER...AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY
WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING
PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO
THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL
PREVAIL. YET HIGH TEMPS ON MONDAY ARE ONLY EXPECTED TO MAKE IT INTO
THE LOW 70S THANKS TO THIS CANADIAN AIR MASS. TUESDAY WILL BE
SIMILAR...AS UPPER LEVEL RIDGING FINALLY MOVES IN OVERHEAD AND
LESSONS THE PRESSURE GRADIENT/STRONGEST NWRLY WINDS. AIRMASS
MODIFICATION WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE
REMAINDER OF THE EXTENDED...HOWEVER WE LIKELY WON/T SEE TEMPS HIT
ABOVE THE 80 DEGREE MARK UNTIL AT LEAST NEXT FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 745 AM EDT FRI SEP 19 2014
ASIDE FROM MAINLY VALLEY FOG LIFTING AND DISSIPATING THROUGH ABOUT 13Z...
VFR SHOULD PREVAIL DURING MOST OF THE PERIOD IN ALL LOCATIONS. THE
EXCEPTIONS TO THIS IS THE IFR OR MVFR FOG IN A FEW SPOTS INITIALLY
IMPROVING TO VFR...POSSIBLE MVFR IN ANY SHOWERS THAT DEVELOP BETWEEN
17Z AND 23Z...AND MAINLY VALLEY FOG LATE IN THE PERIOD WHERE MVFR OR
IFR IS POSSIBLE. FOR THE FOG LATE IN THE PERIOD...SJS AND SME APPEAR
TO HAVE THE HIGHEST CHANCE OF DROPPING TO IFR AMONG THE TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
745 AM EDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 740 AM EDT FRI SEP 19 2014
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT SATELLITE IMAGERY AND
OBSERVATIONS. THIS LED TO VERY LITTLE CHANGE...JUST A FRESHENING UP
OF THE HOURLY TEMP AND DEWPOINT CURVES OVER THE NEXT FEW HOURS.
VALLEY FOG ACROSS THE SOUTHERN AND SOUTHEASTERN COUNTIES HAS LIKELY
ALREADY BEGUN TO LIFT AND SHOULD DISSIPATE BY AROUND 9 AM. THE 6Z
GFS AND NAM SUGGESTED THE POTENTIAL FOR A STRAY SHOWER ACROSS THE
SOUTHEASTERN NEAR THE VA OR WV BORDER. THE MODEL CONSENSUS SEEMS TO
INDICATE THE HIGHEST CHANCES FOR AN ISOLATED SHOWER FROM HARLAN
COUNTY NORTHEAST TO PIKE COUNTY AND POSSIBLY INTO THE NEXT TIER OF
COUNTIES TO THE NORTH.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM EDT FRI SEP 19 2014
THROUGH TONIGHT...UPPER LEVEL RIDGING CURRENTLY CENTERED OVER THE
PLAINS STATES WILL BUILD EAST INTO THE LOWER OH VALLEY REGION TODAY
AND INTO TONIGHT. MEANWHILE A WEAK UPPER LOW/TROUGH OF LOW PRESSURE
WILL REMAIN ACROSS THE SOUTHEASTERN CONUS. FURTHER TO THE NORTHWEST A
SERIES OF SHORTWAVES IS EXPECTED TO LEAD TO AN UPPER LEVEL TROUGH
WORKING INTO THE GREAT LAKES REGION BY THE END OF THE PERIOD. AT THE
SFC...HIGH PRESSURE CURRENTLY CENTERED OVER QUEBEC AND EXTENDING
SOUTHWEST INTO THE OH VALLEY REGION WILL MOVE EAST SOUTHEAST TO NEAR
CAPE COD THIS EVENING AND THEN OFF THE NORTHEAST US COAST TONIGHT AND
INTO SATURDAY. AS THE HIGH MOVES EAST...AN INVERTED TROUGH IS
EXPECTED TO DEVELOP ACROSS THE REGION TODAY AND THEN SHIFT WEST AND
WEAKEN TONIGHT. TO THE EAST OF THE CREST OF THE APPALACHIANS...A
RIDGE OF HIGH PRESSURE IS EXPECTED TO EXTEND SOUTHWEST FROM THIS SFC
HIGH INTO THE APPALACHIANS GENERALLY ALONG OR JUST TO THE EAST OF THE
BLUE RIDGE MOUNTAINS LATER TODAY THROUGH EARLY ON SATURDAY. THIS WILL
RESULT IN A RATHER TIGHT PRESSURE GRADIENT...RATHER BRIEFLY THIS
EVENING INTO THE OVERNIGHT HOURS ACROSS THE HIGHER TERRAIN NEAR THE
VA BORDER.
ON SATURDAY THIS RIDGE WILL WEAKEN AS THE UPPER LEVEL TROUGH
APPROACHES THE LOWER OH VALLEY AS THE RIDGE RETREATS WEST AND
BUILDS TOWARD THE NORTHERN ROCKIES. A SFC COLD FRONT WILL ALSO
APPROACH THE LOWER OH VALLEY REGION AT THE END OF THE PERIOD.
ONCE EARLY MORNING VALLEY FOG DISSIPATES...A GENERAL WARMING TREND
IS EXPECTED THROUGH SATURDAY AS THE HIGH DEPARTS TO THE EAST. SOME
MOISTURE SHOULD BE DRAWN WEST AROUND THE DEPARTING HIGH LEADING TO
CU DEVELOPMENT ACROSS THE SOUTHEASTERN PART OF THE CWA FORM MIDDAY
INTO THE AFTERNOON. SOME OF THIS MAY BECOME DEEP ENOUGH FOR A FEW
ISOLATED SHOWERS BELOW THE MID LEVEL CAP. THE NAM IS GENERALLY THE
MOST AGGRESSIVE WITH THIS AMONG THE OPERATIONAL MODELS. THE END OF THE
THE 5Z HRRR RUN GENERALLY KEEPS THE ACTIVITY SOUTH OF THE REGION
THROUGH 20Z.
DIURNAL CU SHOULD DISSIPATE THIS EVENING...BUT MODELS KEEP THE LAYER
NEAR 800 TO 850 MB RATHER MOIST TONIGHT. SOME STRATOCU NEAR THE LEVEL
WILL BE POSSIBLE TONIGHT. PATCHY VALLEY FOG SHOULD STILL
DEVELOP...ESPECIALLY NORTH OF THE VA BORDER COUNTIES. MEANWHILE
DURING THE EVENING WHEN THE PRESSURE GRADIENT IS HIGHEST NEAR THE VA
BORDER AND A PERIOD OF SUSTAINED WINDS OF 10 TO 15 MPH IS
POSSIBLE...ESPECIALLY ACROSS THE EXPOSED RIDGETOPS SUCH AS THE
FLATWOODS AREA OF PIKE COUNTY...PORTIONS OF THE CREST OF PINE
MOUNTAINS AND BLACK MOUNTAINS. MOST LOCATIONS WILL EXPERIENCE LIGHTER
WINDS...WITH VALLEYS FURTHER NORTHWEST LIKELY DECOUPLED. HIGHER
ANTICIPATED DEWPOINTS...A LARGER PRESSURE GRADIENT AND THE POTENTIAL
FOR A FEW CLOUDS SHOULD BRING WARMER MIN T TONIGHT. SOUTH TO
EVENTUALLY SOUTHWEST FLOW WILL BRING WARMER AIR INTO THE REGION ON
SATURDAY. OUTSIDE OF THE HIGH TERRAIN...MAX TEMPS SHOULD REACH THE
LOW TO MID 80S. PRECIPITATION CHANCES ASSOCIATED WITH THE NEXT SYSTEM
SHOULD HOLD OFF UNTIL THE LONG TERM PERIOD.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 307 AM EDT FRI SEP 19 2014
THE EXTENDED PERIOD WILL START OFF ON 0Z SUNDAY WITH A DEEPENING
TROUGH IN THE LONGWAVE PATTERN ACROSS THE DAKOTAS. THIS WILL QUICKLY
MOVE SOUTHEASTWARD ACROSS THE UPPER GREAT LAKES BY SUNDAY
MORNING...QUICKLY PUSHING LOWERING HEIGHTS INTO THE OHIO RIVER
VALLEY THROUGHOUT THE DAY. AT THE SURFACE...A COLD FRONTAL BOUNDARY
WILL PUSH SE TOWARDS KY AS WELL...AND REACH THE OHIO RIVER JUST
AFTER 0Z SUNDAY. MODELS ARE FINALLY COMING INTO A MUCH BETTER
AGREEMENT FOR TIMING OF THE PRECIP ACCOMPANYING THE FRONT...WITH
POPS EXPECTED TO MOVE INTO THE NW PART OF THE CWA AS EARLY AS 12Z
SUNDAY...THEN QUICKLY SPREAD ACROSS THE REMAINING CWA DURING THE
AFTERNOON...BEFORE EXITING SE OF THE REGION BETWEEN 0 AND 6Z MONDAY.
LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL
INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...THOUGH IT HAS
IMPROVED SLIGHTLY FROM RUN TO RUN OVER THE LAST SEVERAL DAYS. WILL
CONTINUE TO SUPPORT IDEA FOR SOME SCATTERED THUNDERSTORMS DURING THE
DAY SUNDAY...WITH THE BEST CHANCE AROUND AND JUST AFTER 18Z...THEN
DROPPING OFF QUICKLY AS A LOW LEVEL INVERSION SETS UP AFTER 0Z
MONDAY AND WINDS QUICKLY TURN MORE NRLY BEHIND THE FRONTAL PASSAGE.
SOUTHERLY WINDS LEADING UP TO THIS FRONTAL PASSAGE WILL BRING ENOUGH
WAA TO KEEP TEMPS NEAR THE 80 DEGREE MARK FOR DURING THE DAY SUNDAY.
HOWEVER...AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY
WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING
PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO
THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL
PREVAIL. YET HIGH TEMPS ON MONDAY ARE ONLY EXPECTED TO MAKE IT INTO
THE LOW 70S THANKS TO THIS CANADIAN AIR MASS. TUESDAY WILL BE
SIMILAR...AS UPPER LEVEL RIDGING FINALLY MOVES IN OVERHEAD AND
LESSONS THE PRESSURE GRADIENT/STRONGEST NWRLY WINDS. AIRMASS
MODIFICATION WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE
REMAINDER OF THE EXTENDED...HOWEVER WE LIKELY WON/T SEE TEMPS HIT
ABOVE THE 80 DEGREE MARK UNTIL AT LEAST NEXT FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 745 AM EDT FRI SEP 19 2014
ASIDE FROM MAINLY VALLEY FOG LIFTING AND DISSIPATING THROUGH ABOUT 13Z...
VFR SHOULD PREVAIL DURING MOST OF THE PERIOD IN ALL LOCATIONS. THE
EXCEPTIONS TO THIS IS THE IFR OR MVFR FOG IN A FEW SPOTS INITIALLY
IMPROVING TO VFR...POSSIBLE MVFR IN ANY SHOWERS THAT DEVELOP BETWEEN
17Z AND 23Z...AND MAINLY VALLEY FOG LATE IN THE PERIOD WHERE MVFR OR
IFR IS POSSIBLE. FOR THE FOG LATE IN THE PERIOD...SJS AND SME APPEAR
TO HAVE THE HIGHEST CHANCE OF DROPPING TO IFR AMONG THE TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
736 AM EDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT FRI SEP 19 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A LOW AMPLITUDE PATTERN WITH A
MID/UPPER LEVEL RIDGE FROM THE PLAINS TOWARD THE UPPER MS VALLEY AND
A TROUGH FROM SRN SASK INTO THE NRN ROCKIES. AT THE SFC...SRLY FLOW
WAS INCREASING OVER THE UPPER MS VALLEY INTO THE WRN LAKES AS THE
PRES GRADIENT STRENGTHENS BETWEEN A TROUGH FROM MANITOBA INTO THE
NRN PLAINS AND HIGH PRES OVER QUEBEC. INCREASED LOW LEVEL MOISTURE
ADVECTION HAS ALSO BROUGHT SOME LOW CLOUDS INTO MUCH OF CNTRL WI AND
UPPER MI. SOME LIGHT SHOWERS OVER NR CNTRL MN WERE SUPPORTED BY
310K-315K ISENTROPIC ASCENT WITH FAVORABLE 850 MB THETA-E ADVECTION
ON 40-50 KNOT WINDS.
TODAY...RAIN SHOULD CONTINUE TO SPREAD TOWARD UPPER MI AS A WEAK
SHORTWAVE AND THE STRONGER 850 MB THETA-E ADVECTION MOVE IN. WITH
MODEL TRENDS HAVE SLOWING THE ARRIVAL OF THE PCPN INTO UPPER MI AND
THE PRESENCE OF A DRY 850-600 MB LAYER...RAIN CHANCES WILL INCREASE
INTO THE WEST HALF OF THE CWA MAINLY IN THE MID TO LATE AFTERNOON.
ONLY CHANCE FOR TSRA WAS MENTIONED OVER THE FAR WEST WHERE MUCAPE
VALUES CLIMB TO NEAR 800 J/KG. AS THE LOW CLOUDS MIX OUT TOWARD
AFTERNOON AND DAYTIME HEATING INCREASES...A BETTER PORTION OF THE
40-50 KNOT 900-850 MB WINDS MAY MIX TOWARD THE SFC. HOWEVER...THE
DEPTH OF THE MIXED LAYER SHOULD MAINLY ALLOW WIND GUSTS TO NEAR 30
KNOTS. HOWEVER...THERE MAY BE A PERIOD LATE THIS AFTERNOON OVER THE
EAST WHERE THE STRONG WINDS ABOVE THE LAKE MI MARINE LAYER ARE ABLE
TO MIX TOWARD THE SFC OVER THE EAST AND WINDS GUST INTO THE 30-40 MPH
RANGE FOR A TIME...ESPECIALLY FROM NEAR GRAND MARAIS TO NEWBERRY.
TONIGHT...SCT/NMRS SHOWERS AND A FEW THUNDERSTORMS WILL SPREAD
THROUGH THE CWA IN THE EVENING AS THE SFC AND MID LEVEL TROUGH APPROACH
AND THE AXIS OF HIGHER MOISTURE(PWAT TO 1.5 INCHES)/INSTABILITY
(MUCPAE TO NEAR 1K J/KG) MOVE IN. THE POTENTIAL FOR ELEVATED TSRA
REMAINS WITH 850 MB DEWPOINTS TO NEAR 14C.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI SEP 19 2014
NAM SHOWS A 500 MB TROUGH OVER THE UPPER GREAT LAKES 12Z SAT WITH
MORE UPPER LEVEL ENERGY DROPPING SOUTHEAST AND REINFORCING THE
TROUGH ON SUN AND INTO SUN NIGHT. DID NOT MAKE TOO MANY CHANGES TO
THE GOING FORECAST EXCEPT MOVED POPS A BIT FURTHER SOUTH LATER
SUNDAY AS A COLD FRONT MOVES THROUGH THE AREA. WENT WITH CHANCE POPS
MOSTLY FOR SAT INTO SUN...BUT HAVE SOME LIKELY POPS ACROSS THE
CENTRAL CWA SAT NIGHT AS NEXT ENERGY ARRIVES WITH MORE MOISTURE. DID
NOT CHANGE TEMPERATURES MUCH EITHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE WESTERN
U.S. 12Z MON WITH A TROUGH OVER THE EASTERN U.S. AND A TROUGH IN THE
DESERT SW. THE RIDGE MOVES INTO THE NORTHERN AND CENTRAL PLAINS 12Z
TUE WITH A TROUGH IN THE CENTRAL ROCKIES. THE RIDGE MOVES INTO THE
UPPER GREAT LAKES 12Z WED WITH THE TROUGH MOVING INTO THE NORTHERN
PLAINS. THE UPPER PATTERN DOES NOT CHANGE MUCH FOR 12Z THU. WHAT
THIS WILL MEAN IS A WARMING TREND IN THE EXTENDED WITH TEMPERATURES
GOING ABOVE NORMAL AND QUIET WEATHER FOR THE FORECAST PERIOD. WILL
ALSO REMAIN DRY FOR THE EXTENDED FORECAST PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 735 AM EDT FRI SEP 19 2014
UPSLOPE FLOW OF LAKE MI MOISTENED AIR INTO COOLER AIR OVER UPPER MI HAS
BROUGHT STRATUS (IFR CIGS) INTO SAW. THESE LOWER CLOUDS SHOULD LIFT
AND SCATTER OUT MID MORNING THRU EARLY AFTN AT KSAW. WITH MAINLY
DOWNSLOPE FLOW AT CMX...VFR CONDITIONS SHOULD PREVAIL THROUGH MOST OF
THE DAY. OTHERWISE...TIGHTENING PRES GRADIENT AHEAD OF APPROACHING
SFC TROF WILL BRING GUSTY S WINDS TO ALL TERMINALS TODAY. FLOW IS
ESPECIALLY FAVORABLE FOR KSAW...AND EXPECT GUSTS TO 30KT OR PERHAPS
HIGHER THERE THIS AFTERNOON. WITH UNCERTAIN COVERAGE OF SHRA AHEAD OF
TROF... ONLY VCSH WAS INCLUDED IN FCST AT KIWD/KCMX LATE IN THE
AFTN/EARLY EVENING. BETTER CHC OF SHRA AND PERHAPS A TSTM WILL ARRIVE
DURING THE EVENING. CONDITIONS MAY FALL TO MVFR AT THAT TIME. BY LATE
TONIGHT...MOISTENING SHOULD BE SUFFICIENT FOR IFR CONDITIONS WITH A
LOWER CHANCE OF LIFR CIGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT FRI SEP 19 2014
SOUTHERLY WINDS WILL INCREASE TODAY WITH LOW PRESSURE APPROACHING
FROM THE WEST AND HIGH PRESSURE JUST EAST OF LAKE SUPERIOR SHIFTING
EASTWARD. 20-30KT SOUTHERLY WINDS ARE EXPECTED ACROSS THE CENTRAL
AND EAST TODAY. A FEW GALES TO 35 KNOTS WILL BE POSSIBLE FOR THE
HIGHER PLATFORMS AND CLOSER TO THE UPPER MI SHORELINE. THE 20-30KT
SOUTH WINDS WILL GRADUALLY DIMINISH ACROSS THE EAST HALF OF THE LAKE
FRIDAY NIGHT THROUGH SATURDAY AS THE TROUGH MOVES ACROSS LAKE
SUPERIOR. EXPECT A PERIOD OF WESTERLY WINDS OF UP TO 20 KNOTS
SATURDAY AFTERNOON AND NW WINDS TO 20 KNOTS SUNDAY BEHIND THIS
TROUGH. WINDS WILL REMAIN UNDER 20 KNOTS THROUGH MUCH OF NEXT WEEK AS
A SERIES OF HIGH PRESSURE SYSTEMS MOVES OVER THE UPPER GREAT LAKES.
THE ONE EXCEPTION WILL BE THE CHANCE OF NORTH WINDS UP TO 25 KNOTS
MONDAY AFTERNOON AND EVENING BEHIND A QUICK-MOVING LOW PRESSURE
TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...
LONG TERM...07
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
959 AM CDT FRI SEP 19 2014
.UPDATE...WV IMAGERY SHOWING WHAT LOOKS LIKE MUCH DRIER AIR OVER THE
REGION THIS MORNING...BUT AREA SOUNDINGS ARE STILL INDICATING LOW/MID
LEVEL MOISTURE. HRRR AND TO A LESSER EXTENT LOCAL WRF ARE BOTH
INDICATING SCATTERED CONVECTION OVER THE FAR SOUTHERN PORTIONS OF THE
AREA THIS AFTERNOON WITH ISOLATED TO THE NORTH. FORECAST CELLS HAVE A
MORE WESTERLY MOVEMENT INDICATING THAT THEY SHOULD REMAIN SOMEWHAT
SHALLOW AS THE EASTERLY FLOW PREVAILS IN THE LOW TO MID LEVELS. UPPED
POPS IN THE GRIDS TO CHANCE IN THE FAR SOUTH WHILE SPREADING THE
SLIGHT CHANCE AREA FURTHER NORTH AND WEST./26/
&&
.AVIATION...LOW CLOUDS AND REDUCED VISIBILITIES ACROSS NORTHERN
ZONES ARE IMPROVING QUICKLY THIS MORNING WITH MAINLY VFR CONDITIONS
ANTICIPATED AT ALL TAF SITES LATE THIS MORNING THROUGH THIS EVENING.
AT LEAST ISOLATED SHOWERS AND STORMS ARE EXPECTED TO DEVELOP IN THE
AFTERNOON AND IN HEAVIER DOWNPOURS (MORE LIKELY SOUTH OF I-20) STRAY
AND BRIEF SUB-VFR CATS CANNOT BE RULED OUT GOING INTO EARLY THIS
EVENING. OTHERWISE...LATE TONIGHT INTO EARLY SATURDAY MORNING EXPECT
AT LEAST PATCHY MVFR VIS REDUCTIONS DUE TO LIGHT FOG.
SURFACE WINDS WILL PRIMARILY BE FROM THE EAST AND SOUTHEAST AND
LIGHT. /BB/
&&
.PREV DISCUSSION... /ISSUED 319 AM CDT FRI SEP 19 2014/
SHORT TERM...TODAY OUR REGION WILL SEE THE PATTERN CHANGE SOME AS
WE TRANSITION FROM A NW FLOW REGIME TO ONE OF S/WV RIDGING. THIS
RIDGING LOOKS TO BE BRIEF AS WE SHIFT TO A NW FLOW PATTERN AGAIN
FOR SUNDAY. TODAY LOOK FOR INCREASING MID LEVEL HEIGHTS AS THE AREA
WILL BE LOCATED ON THE BACKSIDE OF THE S/WV TROUGH. THIS WILL ALSO
SERVER TO PUSH SOUTHWARD MUCH DRIER UPPER LEVEL AIR. WHAT WAS
THOUGHT TO BE A PRECIP FREE DAY TODAY IS LOOKING LIKE IT WILL BE
SUPPORTIVE OF SOME ISO SHOWERS AS LOW/MID LEVEL MOISTURE WILL BE
SLOWER TO EXIT THE AREA. STILL...THE EFFECTS OF THE RIDGING AND
DRYING ALOFT LOOK TO LIMIT ACTIVITY. WILL GO WITH 10-20% POPS AND
ISO SHRA WORDING FOR THIS AFTERNOON. SUBSIDENCE AND DRYING ALOFT
WILL CONTINUE INTO SAT AND BE MORE PRONOUNCED AND REALLY LIMIT
CLOUDS AND ANY POTENTIAL FOR PRECIP.
AS FOR TEMPS...HIGHS WILL CONTINUE TO ON THE WARM SIDE AND ABV NORMS
FOR MID SEP. LOOK FOR HIGHS 88-92 TODAY AND SAT. LOW TEMPS WILL BE A
TAD LOWER THE NEXT TWO MORNINGS THANKS TO CLEAR SKIES OVERNIGHT AND
SOME LOWER LEVEL DRY AIR ALLOWING FOR MORE READINGS TO REACH THE MID
60S. /CME/
LONG TERM...SUNDAY THROUGH NEXT THURSDAY
OVERALL, THE LONG TERM CAN BE SUMMARIZED BY ABOVE NORMAL TEMPERATURES
SUNDAY THEN A NICE DOWNWARD TREND TO NORMAL TO SLIGHTLY BELOW NORMAL
READINGS THROUGH THE NEXT WEEK AS REINFORCING COOL AIR INTRUSIONS
OCCUR OVER THE ARKLAMISS.
BY THE SECOND HALF OF THE WEEKEND, A SOUTH-BOUND COOL FRONT WILL BE
APPROACHING THE ARKLAMISS FROM THE NORTH AS STRONGER TROUGHING OVER
THE GREAT LAKES DRIVES STRONGER NW FLOW TOWARDS THE REGION. A
MOISTURE RIBBON LOOKS TO BE TRAPPED AHEAD OF THE APPROACHING FRONT
AND THIS WILL ACT TO INCREASE PWATS TO NEAR 1.5" SUNDAY AFTN FOR THE
NORTH 1/3 TO 1/2 OF THE AREA. HOWEVER, LOW-LEVEL CONVERGENCE LOOKS
TO BE WEAK IN CONJUNCTION WITH SLIGHTLY DRY LOW LEVELS PER INVERTED
V BUFR SOUNDINGS ALONG AND AHEAD OF FRONT. FEEL A BAND OF SHOWERS
COULD FORM ALONG BOUNDARY AS IT MOVES THROUGH LATE SUNDAY BUT WHAT
RAIN COVERAGE THERE IS, SHOULD BE CONFINED TOWARDS TN/MS LINE AND
WILL ONLY CARRY MINIMAL 15-20% POPS.
ALL LONG RANGE MODELS ARE IN AGREEMENT OF FRONTAL PASSAGE THROUGH
REGION BY MONDAY AFTERNOON WITH LIMITED PRECIPITATION BUT THE EC IS
SLIGHTLY SLOWER POSSIBLY ALLOWING FOR INSTABILITY INDUCED SHOWERS
ALONG THE FAR SOUTH. YET, FEEL MOST OF REGION WILL BE DRY MONDAY AS
DRIER AND COOLER AIR MOVES IN WITH CLOUDS CLEARING THROUGH THE DAY.
UPPER 40S TO LOWER 50S DEWPOINTS WILL SETTLE OVER REGION TUESDAY
MORNING WITH SLIGHT UPWARD MODIFICATION TO END OF WEEK ALLOWING FOR
COMFORTABLE LOWS AT LEAST INTO THE UPPER 50S WITH SOME MID 50S
POSSIBLE. WOULD BE MORE CONFIDENT IN MID TO LOW 50S IN THIS SET UP
BUT DECENT PRESSURE GRADIENT KEEPING WINDS UP OVERNIGHT COULD ALLOW
FOR SOME MIXING AND KEEP TEMPERATURES FROM DROPPING TO FULL LOW
POTENTIAL. HIGHS WILL LOOK TO TOP OUT IN THE MID TO UPPER 80S WITH
GOOD AMOUNT OF SUN AS A NICE REX BLOCK TO OUR EAST ALLOWS FOR
CONTINUAL LOW-LEVEL EAST/NE COOL AIR FETCH. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 90 67 91 64 / 17 5 2 3
MERIDIAN 91 65 89 62 / 18 6 1 3
VICKSBURG 90 65 92 64 / 17 4 2 3
HATTIESBURG 92 68 91 65 / 26 6 3 2
NATCHEZ 89 67 90 66 / 23 5 5 3
GREENVILLE 90 67 91 66 / 12 2 4 6
GREENWOOD 90 66 91 65 / 15 3 4 5
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
920 AM MDT FRI SEP 19 2014
.UPDATE...
THE SYSTEM THAT BROUGHT THE SHOWERS AND ISOLATED THUNDERSTORMS TO
THE FORECAST AREA LAST NIGHT INTO EARLY THIS MORNING HAS SHIFTED
EAST INTO THE DAKOTAS THIS MORNING. AS A RESULT...HAVE REMOVED
SHOWER/THUNDERSTORMS FROM THE FORECAST ACROSS THE EAST FOR THIS
MORNING. HOWEVER...A FEW LIGHT RADAR RETURNS CONTINUE TO SHOW FROM
ABOUT TREASURE COUNTY TO FALLON COUNTY SO WILL KEEP A SLIGHT
CHANCE FOR SOME SPRINKLES FOR THESE AREAS FOR THE REMAINDER OF THE
MORNING. A DRY NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE FORECAST
AREA THIS AFTERNOON. COOLER 700MB TEMPERATURES WILL ALLOW FOR SOME
CLOUD DEVELOP TODAY AS THE SUN WARMS THE LOWER ATMOSPHERE. WINDS
WILL BEGIN TO MIX OUT AND BECOME NORTHWEST AND GUSTY IN THE 15 TO
25 MPH RANGE FOR AREAS MAINLY EAST OF BILLINGS. UPDATED FORECAST
HAS BEEN SENT FOR THE ABOVE ADJUSTMENTS. HOOLEY
&&
.SHORT TERM...VALID FOR TDY AND SAT...
RADAR TRENDS WERE REFLECTING THE LAST FEW HRRR RUNS IN MOVING
PRECIPITATION RAPIDLY OUT OF THE AREA WITH JUST A HINT OF SOME
PRECIPITATION POSSIBLE OVER SE MT. SO WILL UPDATE TO REDUCE POPS
THIS MORNING. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
MADE A FEW CHANGES TO THE EXTENDED FORECAST PACKAGE FOR A COUPLE
OF REASONS. THE FIRST CHANGE WAS TO RAISE POPS A BIT FOR THE
SUNDAY NIGHT THROUGH MONDAY NIGHT PERIOD. THIS IS IN RESPONSE TO
THE UPPER LOW CURRENTLY SITTING OVER CENTRAL CALIFORNIA. MODELS
PULL THIS SYSTEM INTO NORTHERN WYOMING AND SOUTHERN MONTANA SUNDAY
NIGHT AND EARLY MONDAY. MODELS HAVE TRENDED FARTHER NORTH WITH
THIS FEATURE AND BECAUSE OF SUCH PULL PRECIPITABLE WATERS AS HIGH
AS 1.5 INCHES INTO THE EASTERN HALF OF MONTANA...WHICH IS QUITE
HIGH FOR THIS TIME OF YEAR. JET FORCING WITH THE UPPER LOW IS
MINIMAL...BUT GIVEN THE AMOUNT OF PWAT AVAILABLE...SHOULD NOT BE
TERRIBLY DIFFICULT TO GET SHOWERS TO FORM.
THE SYSTEM KICKS OUT TUESDAY AFTERNOON AND NIGHT. THIS WILL DRY
THINGS OUT FROM WEST TO EAST. RIDGING FOLLOWS FOR WEDNESDAY. THIS
RIDING WILL QUICKLY BE REPLACED BY STRONG SOUTHWEST FLOW FOR A
STRONG DOWNSLOPE PATTERN. THIS IS THE SECOND CHANGE TO THE
FORECAST PACKAGE MADE...A CHANGE TO RAISE TEMPERATURES WEDNESDAY
INTO FRIDAY WITH THIS STRONG DOWNSLOPE PATTERN. WOULD EXPECT DRY
AIR TO GET PULLED UP FROM THE DESERT SOUTHWEST AND BECAUSE OF
THAT...MID 80S ARE QUITE POSSIBLE WEDNESDAY AND THURSDAY. THE FLY
IN THE OINTMENT OF WARMER TEMPERATURES COULD BE SOME CLOUD COVER
AS MID TO HIGH LEVEL MOISTURE TRIES TO INCREASE AHEAD OF AN
ADVANCING COLD FRONT. THIS FRONT APPROACHES THE WEST THURSDAY
EVENING AND WILL LEAD TO COOLER TEMPERATURES FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. TWH
&&
.AVIATION...
PARTLY SUNNY SKIES ALONG WITH VFR CONDITIONS WILL PREVAIL FOR THE
REMAINDER OF THE DAY. NORTHWEST WINDS MAY GUST AROUND 20KTS
ESPECIALLY EAST OF KBIL. OTHERWISE...NO AVIATION HAZARDS ARE
EXPECTED. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 078 052/074 049/076 053/076 054/080 054/082 054/080
1/B 00/U 00/U 13/T 31/B 11/U 11/B
LVM 075 043/076 041/076 047/074 049/078 048/080 049/078
1/N 10/U 00/U 23/T 21/B 11/B 12/T
HDN 080 050/076 045/078 052/078 052/080 052/084 052/082
1/B 00/U 00/U 13/T 31/B 11/U 11/B
MLS 080 051/075 045/076 052/079 054/078 053/083 053/084
1/N 00/U 00/U 02/T 21/B 11/U 11/B
4BQ 081 051/076 046/076 053/079 054/077 052/082 052/084
1/B 00/U 00/U 12/T 32/T 11/B 11/B
BHK 078 049/073 041/073 047/077 051/073 049/079 050/081
1/N 00/N 00/U 02/T 22/T 11/U 11/B
SHR 077 048/075 045/077 051/075 049/076 049/080 050/080
1/B 10/U 00/U 24/T 42/T 10/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
552 AM MDT FRI SEP 19 2014
.UPDATE...
RADAR TRENDS WERE REFLECTING THE LAST FEW HRRR RUNS IN MOVING
PRECIPITATION RAPIDLY OUT OF THE AREA WITH JUST A HINT OF SOME
PRECIPITATION POSSIBLE OVER SE MT. SO WILL UPDATE TO REDUCE POPS
THIS MORNING. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND SAT...
AREAS OF SHOWERS AND THUNDERSTORMS WERE MOVING NE THROUGH MT IN A
POST-FRONTAL ENVIRONMENT AND AHEAD OF AN APPROACHING UPPER TROUGH.
MOST OF THE ACTIVITY WAS OVER SE MT EARLY THIS MORNING. THE
RIGHT-REAR QUADRANT OF AN UPPER JET WAS ALSO SUPPORTING THE
PRECIPITATION.
MODELS WERE SIMILAR IN MOVING THE UPPER TROUGH INTO E MT TODAY.
WHILE THE SSEO DID NOT HAVE A GOOD HANDLE ON THE PRECIPITATION
EARLY THIS MORNING...THE HRRR WAS DOING WELL AND MOVED EVERYTHING
OUT OF THE AREA AROUND 12Z. CONCERNED THIS MOVEMENT MAY BE A
LITTLE FAST GIVEN RADAR TRENDS...SO HAVE KEPT POPS OVER THE AREA
THIS MORNING...MAINLY E AND S OF KBIL. ALSO RAISED POPS TO CHANCE
IN SE MT. GIVEN STEEP MID AND UPPER LEVEL LAPSE RATES ON FORECAST
SOUNDINGS...WILL KEEP THUNDER IN THE FORECAST THIS MORNING. FOR
THE AFTERNOON...REMOVED POPS OVER KSHR DUE TO DOWNSLOPING AND KEPT
A LOW POP OVER THE NE BIG HORNS. MODELS AGREED THAT AIRMASS WILL
STABILIZE THIS AFTERNOON AS IT DRIES OUT. BASED ON MODEL
SOUNDINGS...WILL HAVE A BREEZY TO WINDY DAY OVER MOST AREAS WITH
THE FAST FLOW ALOFT. LOWERED TEMPERATURES A COUPLE OF DEGREES
BASED ON MIXING PROFILES AND WENT CLOSE TO CONSALL GUIDANCE.
WILL HAVE A FLAT NW FLOW OVER THE AREA TONIGHT...THEN UPPER
RIDGING AND DRY WEATHER BUILDS IN FOR THE REMAINDER OF THE
PERIOD. HAVE DRIED OUT THE EVENING WITH LIFT AND MOISTURE
CONTINUING TO EXIT THE REGION.
SAT WILL BE LESS WINDY THAN TODAY...AS FAST FLOW ALOFT SHIFTS E
WITH THE UPPER TROUGH. HOWEVER IT WILL STILL BE WINDY OVER PLACES
LIKE KBHK AND EKALAKA. EASTERLY WINDS ON SAT WILL INHIBIT MIXING
OVER THE AREA SO LOWERED TEMPERATURES SLIGHTLY TOWARD THE
SUPERBLEND GUIDANCE. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
MADE A FEW CHANGES TO THE EXTENDED FORECAST PACKAGE FOR A COUPLE
OF REASONS. THE FIRST CHANGE WAS TO RAISE POPS A BIT FOR THE
SUNDAY NIGHT THROUGH MONDAY NIGHT PERIOD. THIS IS IN RESPONSE TO
THE UPPER LOW CURRENTLY SITTING OVER CENTRAL CALIFORNIA. MODELS
PULL THIS SYSTEM INTO NORTHERN WYOMING AND SOUTHERN MONTANA SUNDAY
NIGHT AND EARLY MONDAY. MODELS HAVE TRENDED FARTHER NORTH WITH
THIS FEATURE AND BECAUSE OF SUCH PULL PRECIPITABLE WATERS AS HIGH
AS 1.5 INCHES INTO THE EASTERN HALF OF MONTANA...WHICH IS QUITE
HIGH FOR THIS TIME OF YEAR. JET FORCING WITH THE UPPER LOW IS
MINIMAL...BUT GIVEN THE AMOUNT OF PWAT AVAILABLE...SHOULD NOT BE
TERRIBLY DIFFICULT TO GET SHOWERS TO FORM.
THE SYSTEM KICKS OUT TUESDAY AFTERNOON AND NIGHT. THIS WILL DRY
THINGS OUT FROM WEST TO EAST. RIDGING FOLLOWS FOR WEDNESDAY. THIS
RIDING WILL QUICKLY BE REPLACED BY STRONG SOUTHWEST FLOW FOR A
STRONG DOWNSLOPE PATTERN. THIS IS THE SECOND CHANGE TO THE
FORECAST PACKAGE MADE...A CHANGE TO RAISE TEMPERATURES WEDNESDAY
INTO FRIDAY WITH THIS STRONG DOWNSLOPE PATTERN. WOULD EXPECT DRY
AIR TO GET PULLED UP FROM THE DESERT SOUTHWEST AND BECAUSE OF
THAT...MID 80S ARE QUITE POSSIBLE WEDNESDAY AND THURSDAY. THE FLY
IN THE OINTMENT OF WARMER TEMPERATURES COULD BE SOME CLOUD COVER
AS MID TO HIGH LEVEL MOISTURE TRIES TO INCREASE AHEAD OF AN
ADVANCING COLD FRONT. THIS FRONT APPROACHES THE WEST THURSDAY
EVENING AND WILL LEAD TO COOLER TEMPERATURES FRIDAY ALONG WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. TWH
&&
.AVIATION...
A FEW SHOWERS AND THUNDERSTORMS WILL LINGER OVER SOUTHEAST
MONTANA THIS MORNING. THIS PRECIPITATION WILL QUICKLY EXIT THE
AREA EARLY THIS MORNING. THE REST OF THE DAY WILL BE DRY AS WEST
TO NORTHWEST WINDS INCREASE. EXPECT GUSTS TO 20KTS ACROSS MOST OF
THE AREA TODAY. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 078 052/074 049/076 053/076 054/080 054/082 054/080
3/B 00/U 00/U 13/T 31/B 11/U 11/B
LVM 075 043/076 041/076 047/074 049/078 048/080 049/078
3/N 10/U 00/U 23/T 21/B 11/B 12/T
HDN 080 050/076 045/078 052/078 052/080 052/084 052/082
4/B 00/U 00/U 13/T 31/B 11/U 11/B
MLS 080 051/075 045/076 052/079 054/078 053/083 053/084
4/N 00/U 00/U 02/T 21/B 11/U 11/B
4BQ 081 051/076 046/076 053/079 054/077 052/082 052/084
4/T 00/U 00/U 12/T 32/T 11/B 11/B
BHK 078 049/073 041/073 047/077 051/073 049/079 050/081
4/N 00/N 00/U 02/T 22/T 11/U 11/B
SHR 077 048/075 045/077 051/075 049/076 049/080 050/080
5/B 10/U 00/U 24/T 42/T 10/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
855 AM CDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 855 AM CDT FRI SEP 19 2014
AS OF 1330 UTC...THE SURFACE COLD FRONT WAS LOCATED FROM NEAR
CAVALIER IN NORTHEAST NORTH DAKOTA THROUGH SELFRIDGE IN THE SOUTH
CENTRAL. SCATTERED RAIN SHOWERS WITH ISOLATED THUNDERSTORM
ACTIVITY WILL CONTINUE ALONG THIS FRONT WITH SURFACE DEWPOINTS IN
THE LOWER 60S. THIS FRONT WILL EXIT INTO THE RED RIVER VALLEY BY
MID DAY. THEREAFTER...DRIER AIR AND WELL MIXED CONDITIONS
OVERTAKE MUCH OF THE AREA BEHIND THIS FRONT. A SECONDARY COLD
FRONT/SURFACE TROUGH ACROSS SOUTHERN SASKATCHEWAN THIS MORNING
WILL PROPAGATE INTO THE US HIGHWAY 2 CORRIDOR THIS
AFTERNOON...AND WILL BE THE FOCUS FOR ADDITIONAL THUNDERSTORM
DEVELOPMENT.
UPDATE ISSUED AT 626 AM CDT FRI SEP 19 2014
SHOWERS WITH A FEW THUNDERSTORMS CONTINUE TO MOVE THROUGH PORTIONS
OF SOUTHERN NORTH DAKOTA...AND ANOTHER AREA STARTING TO DEVELOP
OVER NORTH-CENTRAL NORTH DAKOTA. THIS FALLS WELL IN LINE WITH
LATEST HRRR OUTPUT. MORNING UPDATE WILL ADDRESS THESE AREAS AND
REMOVE POPS OVER THE FAR WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI SEP 19 2014
THIS MORNING A COLD FRONT WAS MOVING THROUGH WESTERN/CENTRAL NORTH
DAKOTA. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE
PRIMARILY FOCUSED ALONG THE FRONT AND PARALLEL/ON THE SOUTH SIDE
OF AN H300 JET. TO THE NORTH ISOLATED SHOWERS WERE ACROSS
SOUTHERN SASKATCHEWAN ASSOCIATED WITH THE SHORTWAVE TROUGH AT
H500. FOLLOWED THE HRRR AND NAM FOR POP GUIDANCE THIS MORNING.
BEST CHANCE FOR PRECIP WILL REMAIN ALONG THE SOUTH DAKOTA
BORDER...MAINLY SOUTH CENTRAL THIS AM. PRECIP ACROSS THE SOUTH
WILL GRADUALLY DIMINISH THIS MORNING AS SUBSIDENCE BEHIND THE
FRONT AND H300 JET TAKES HOLD. THEN THE EXIT REGION OF AN UPSTREAM
H300 JET WILL POSITION ITSELF TO SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS ALONG THE NORTHERN BORDER THIS AFTERNOON. IT WILL BE
A LITTLE E BREEZY WEST AFTER THIS AFTERNOON IN THE WAKE OF THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI SEP 19 2014
SOME SHOWERS/THUNDERSTORMS MAY LINGER INTO SATURDAY PRIMARILY OVER
NORTHERN INTO CENTRAL/EASTERN NORTH DAKOTA AS AREA REMAINS UNDER
CYCLONIC FLOW AND A POTENT SHORT WAVE MOVES THROUGH THE AREA. GUSTY
WINDS ARE EXPECTED TO DEVELOP THROUGHOUT THE AREA AS THE WAVE DIVES
THROUGH AND STRONGER WINDS MIX DOWN. WINDS WILL TAPER BY EVENING
WITH PRECIP ENDING AS UPPER RIDGE BUILDS OVER THE ROCKIES. QUIET
WEATHER EXPECTED TO START THE WEEK AS RIDGE AXIS WORKS EAST. BY
TUESDAY...A COMPACT UPPER LOW WORKS THROUGH THE RIDGE AND APPROACHES
THE REGION...SLOWLY WORKING OVER THE AREA THROUGH MID-WEEK. MODELS
STILL STRUGGLING SOME ON THE PLACEMENT OF THIS SYSTEM THOUGH AT THIS
TIME IT APPEARS THAT MOST OF THE PRECIP SHOULD STAY SOUTH OF THE
AREA SO WILL KEEP POPS ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 854 AM CDT FRI SEP 19 2014
A COLD FRONT ACROSS CENTRAL THROUGH NORTHEAST NORTH DAKOTA AS OF
1330 UTC WILL MOVE INTO MINNESOTA THIS AFTERNOON. ISOLATED TO
SCATTERED RAIN SHOWERS AND THUNDERSTORMS WILL CONTINUE AHEAD OF
THE FRONT. A SECOND COLD FRONT WILL ENTER NORTHERN NORTH DAKOTA
THIS AFTERNOON...YIELDING A THREAT OF THUNDERSTORMS AT KISN AND
KMOT THIS AFTERNOON AND EVENING. STRONG WESTERLY WIND GUSTS NEAR
30 KTS ARE EXPECTED ACROSS MUCH OF THE AREA THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 626 AM CDT FRI SEP 19 2014
SHOWERS WITH A FEW THUNDERSTORMS CONTINUE TO MOVE THROUGH PORTIONS
OF SOUTHERN NORTH DAKOTA...AND ANOTHER AREA STARTING TO DEVELOP
OVER NORTH-CENTRAL NORTH DAKOTA. THIS FALLS WELL IN LINE WITH
LATEST HRRR OUTPUT. MORNING UPDATE WILL ADDRESS THESE AREAS AND
REMOVE POPS OVER THE FAR WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI SEP 19 2014
THIS MORNING A COLD FRONT WAS MOVING THROUGH WESTERN/CENTRAL NORTH
DAKOTA. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE
PRIMARILY FOCUSED ALONG THE FRONT AND PARALLEL/ON THE SOUTH SIDE
OF AN H300 JET. TO THE NORTH ISOLATED SHOWERS WERE ACROSS
SOUTHERN SASKATCHEWAN ASSOCIATED WITH THE SHORTWAVE TROUGH AT
H500. FOLLOWED THE HRRR AND NAM FOR POP GUIDANCE THIS MORNING.
BEST CHANCE FOR PRECIP WILL REMAIN ALONG THE SOUTH DAKOTA
BORDER...MAINLY SOUTH CENTRAL THIS AM. PRECIP ACROSS THE SOUTH
WILL GRADUALLY DIMINISH THIS MORNING AS SUBSIDENCE BEHIND THE
FRONT AND H300 JET TAKES HOLD. THEN THE EXIT REGION OF AN UPSTREAM
H300 JET WILL POSITION ITSELF TO SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS ALONG THE NORTHERN BORDER THIS AFTERNOON. IT WILL BE
A LITTLE E BREEZY WEST AFTER THIS AFTERNOON IN THE WAKE OF THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI SEP 19 2014
SOME SHOWERS/THUNDERSTORMS MAY LINGER INTO SATURDAY PRIMARILY OVER
NORTHERN INTO CENTRAL/EASTERN NORTH DAKOTA AS AREA REMAINS UNDER
CYCLONIC FLOW AND A POTENT SHORT WAVE MOVES THROUGH THE AREA. GUSTY
WINDS ARE EXPECTED TO DEVELOP THROUGHOUT THE AREA AS THE WAVE DIVES
THROUGH AND STRONGER WINDS MIX DOWN. WINDS WILL TAPER BY EVENING
WITH PRECIP ENDING AS UPPER RIDGE BUILDS OVER THE ROCKIES. QUIET
WEATHER EXPECTED TO START THE WEEK AS RIDGE AXIS WORKS EAST. BY
TUESDAY...A COMPACT UPPER LOW WORKS THROUGH THE RIDGE AND APPROACHES
THE REGION...SLOWLY WORKING OVER THE AREA THROUGH MID-WEEK. MODELS
STILL STRUGGLING SOME ON THE PLACEMENT OF THIS SYSTEM THOUGH AT THIS
TIME IT APPEARS THAT MOST OF THE PRECIP SHOULD STAY SOUTH OF THE
AREA SO WILL KEEP POPS ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 626 AM CDT FRI SEP 19 2014
SCT -SHRA WITH ISOLD -TSRA CAN BE EXPECTED TODAY AS A FRONTAL
BOUNDARY MOVES THRU THE REGION. WITH LIMITED COVERAGE OF
THUNDERSTORMS...WILL REFRAIN FROM MENTIONING IN TERMINAL FORECAST.
OTHERWISE...VFR CONDITIONS ARE EXPECTED. BREEZY WEST TO NORTHWEST
WINDS WILL DEVELOP THIS MORNING. THE WINDS WILL DIMINISH THIS
EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJS
SHORT TERM...WAA
LONG TERM...JJS
AVIATION...JJS
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1003 AM CDT FRI SEP 19 2014
.UPDATE...
A forecast update is in order this morning. Satellite imagery
shows widespread cloud cover, and surface observations have
indicated widespread IFR and LIFR ceilings. Radar imagery shows a
band of rain showers with moderate to occasionally heavy rain,
extending from Eden northwest into southwestern Nolan County. Area
of oderate to heavy rain over West Texas is slowly shifting east or
east-southeast (referenced in the Satellite Precipitation Estimates
product from NESDIS). Will update the forecast, at this time to
increase cloud cover and re-work the PoP field for today.
19
&&
.PREV DISCUSSION... /ISSUED 637 AM CDT FRI SEP 19 2014/
AVIATION...
/12Z TAFS/
Ceilings have come down in many places to less than 2000 ft, but
trying to pin down a prevailing height is akin to playing
whack-a-mole with Mother Nature. In general, ceilings will bounce
around between IFR and MVFR, briefly dropping to less than 500 ft
at times over the next few hours. Visibilities have followed suit
along the I-20 corridor, ranging from 1/4 to 3 miles in the past
hour. Generally improving conditions are anticipated by mid/late
morning, with prevailing VFR conditions anticipated after 16z.
Current convection is expected to weaken this morning, but
additional development is expected this afternoon and tonight. A
VCSH group was appended to all sites excluding KABI this
afternoon. Any cells that develop may produce brief IFR
visibilities and/or MVFR ceilings. Rain chances increase tonight
across the north. Expect a general easterly wind at 10 kts or
less.
Johnson
PREV DISCUSSION... /ISSUED 345 AM CDT FRI SEP 19 2014/
SHORT TERM...
(Today and tonight)
A split flow pattern persists over the western CONUS with a
relatively deep trough along the West Coast, cut off from the
stronger westerlies over the northern tier. The mid/upper-level
ridge remains in place over the southern Rockies and Plains, but
the remnants of Odile are trapped beneath this ridge, moving
very slowly to the east across NM this morning. Copious tropical
moisture has been advected into the region, as evidenced by the
precipitable water values from the 00z raobs. Both the FWD and DRT
precipitable water values are just below two standard deviations
above climatology. However, the 1.95" PWAT at KMAF is above the
99th percentile. In other words, pretty rare! GPS PWAT data
indicates values over 2.00" east of DRT. Southerly 850mb winds of
15-20 kts will continue to advect this moisture poleward
throughout the day.
Analysis of the wind field hints at a very weak surface boundary
(or trough) extending from northwest to southeast across the
CWA. The RAP Mesoanalysis also indicates a bit of a theta-e
gradient over the southwest zones, in the vicinity of the stronger
convection earlier in the evening. The convection over our neck of
the woods continues to weaken this morning, as does the
precipitation moving into the Permian Basin. However, we should
still see at some activity around through the morning hours.
Despite the abundant cloud cover, temperatures are forecast to
warm into the mid/upper 80s across the southern and eastern zones,
which should promote the development of additional convection by
midday. Most of the models favor the southwest half of the
forecast area for the development of showers and thunderstorms
today, likely focusing a bit farther north, primarily over the
western Big Country and Concho Valley tonight.
The hi-res CAMS are suggesting that convection during the daytime
period will be more cellular in nature, keeping the threat for
flash flooding on the low side. However, tonight, as the low-
level jet begins to intensify, we may see this activity grow
upscale. Given the lower flash flood threat for today, no Flash
Flood Watch will be issued at this time. That said, a watch may be
warranted next shift, focused on the overnight period.
LONG TERM...
(Saturday into Thursday)
Potential for heavy rainfall and flooding will continue this
weekend. Remnants of Odile are expected to push northeast into the
Panhandle and Northwest Texas early Saturday. A cold front then
moves through West Central Texas, from northeast to southwest,
Saturday afternoon and night, acting as a continuing focus for
heavy rainfall.
Both the GFS and NAM models indicate heavy rainfall amounts of 1
to 3 inches in the Big Country and Concho Valley, Saturday and
Saturday night. Locally heavier amounts possible as the tropical
atmosphere will be a efficient rainfall producer. Sunday afternoon,
the heavy rainfall focus moves to the Concho Valley and areas
southwest including Crockett county. This occurs, as more stable air
moves in from the northeast. The main potential for heavy rainfall
then moves southwest of the region Sunday night, with Crockett
county having the best chance of rain. Flash flood watches may be
needed this weekend. Of course, rainfall and runoff will be
extremely beneficial as reservoirs are at extremely low levels and
much West Central Texas is in moderate to extreme drought.
Kept a slight chance of showers on Monday with low/mid level
moisture remaining. Rainfall amounts will be light, if the occur.
A more stable atmosphere remains over the region the rest of the
week, as weak surface high pressure builds in.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 83 69 83 70 85 / 50 50 70 50 30
San Angelo 87 70 86 70 86 / 50 50 50 50 40
Junction 89 72 86 72 87 / 40 30 40 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
959 AM CDT Fri Sep 19 2014
.UPDATE...
A forecast update is in order this morning. Satellite imagery
shows widespread cloud cover, and surface observations have
indicated widespread IFR and LIFR ceilings. Radar imagery shows a
band of rain showers with moderate to occasionally rain, extending
from Eden northwest into southwestern Nolan County. Area of
moderate to heavy rain over West Texas is slowly shifting east or
east-southeast. Will update the forecast, at this time to increase
cloud cover and re-work the PoP field for today.
19
&&
.PREV DISCUSSION... /ISSUED 637 AM CDT FRI SEP 19 2014/
AVIATION...
/12Z TAFS/
Ceilings have come down in many places to less than 2000 ft, but
trying to pin down a prevailing height is akin to playing
whack-a-mole with Mother Nature. In general, ceilings will bounce
around between IFR and MVFR, briefly dropping to less than 500 ft
at times over the next few hours. Visibilities have followed suit
along the I-20 corridor, ranging from 1/4 to 3 miles in the past
hour. Generally improving conditions are anticipated by mid/late
morning, with prevailing VFR conditions anticipated after 16z.
Current convection is expected to weaken this morning, but
additional development is expected this afternoon and tonight. A
VCSH group was appended to all sites excluding KABI this
afternoon. Any cells that develop may produce brief IFR
visibilities and/or MVFR ceilings. Rain chances increase tonight
across the north. Expect a general easterly wind at 10 kts or
less.
Johnson
PREV DISCUSSION... /ISSUED 345 AM CDT FRI SEP 19 2014/
SHORT TERM...
(Today and tonight)
A split flow pattern persists over the western CONUS with a
relatively deep trough along the West Coast, cut off from the
stronger westerlies over the northern tier. The mid/upper-level
ridge remains in place over the southern Rockies and Plains, but
the remnants of Odile are trapped beneath this ridge, moving
very slowly to the east across NM this morning. Copious tropical
moisture has been advected into the region, as evidenced by the
precipitable water values from the 00z raobs. Both the FWD and DRT
precipitable water values are just below two standard deviations
above climatology. However, the 1.95" PWAT at KMAF is above the
99th percentile. In other words, pretty rare! GPS PWAT data
indicates values over 2.00" east of DRT. Southerly 850mb winds of
15-20 kts will continue to advect this moisture poleward
throughout the day.
Analysis of the wind field hints at a very weak surface boundary
(or trough) extending from northwest to southeast across the
CWA. The RAP Mesoanalysis also indicates a bit of a theta-e
gradient over the southwest zones, in the vicinity of the stronger
convection earlier in the evening. The convection over our neck of
the woods continues to weaken this morning, as does the
precipitation moving into the Permian Basin. However, we should
still see at some activity around through the morning hours.
Despite the abundant cloud cover, temperatures are forecast to
warm into the mid/upper 80s across the southern and eastern zones,
which should promote the development of additional convection by
midday. Most of the models favor the southwest half of the
forecast area for the development of showers and thunderstorms
today, likely focusing a bit farther north, primarily over the
western Big Country and Concho Valley tonight.
The hi-res CAMS are suggesting that convection during the daytime
period will be more cellular in nature, keeping the threat for
flash flooding on the low side. However, tonight, as the low-
level jet begins to intensify, we may see this activity grow
upscale. Given the lower flash flood threat for today, no Flash
Flood Watch will be issued at this time. That said, a watch may be
warranted next shift, focused on the overnight period.
LONG TERM...
(Saturday into Thursday)
Potential for heavy rainfall and flooding will continue this
weekend. Remnants of Odile are expected to push northeast into the
Panhandle and Northwest Texas early Saturday. A cold front then
moves through West Central Texas, from northeast to southwest,
Saturday afternoon and night, acting as a continuing focus for
heavy rainfall.
Both the GFS and NAM models indicate heavy rainfall amounts of 1
to 3 inches in the Big Country and Concho Valley, Saturday and
Saturday night. Locally heavier amounts possible as the tropical
atmosphere will be a efficient rainfall producer. Sunday afternoon,
the heavy rainfall focus moves to the Concho Valley and areas
southwest including Crockett county. This occurs, as more stable air
moves in from the northeast. The main potential for heavy rainfall
then moves southwest of the region Sunday night, with Crockett
county having the best chance of rain. Flash flood watches may be
needed this weekend. Of course, rainfall and runoff will be
extremely beneficial as reservoirs are at extremely low levels and
much West Central Texas is in moderate to extreme drought.
Kept a slight chance of showers on Monday with low/mid level
moisture remaining. Rainfall amounts will be light, if the occur.
A more stable atmosphere remains over the region the rest of the
week, as weak surface high pressure builds in.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 83 69 83 70 85 / 50 50 70 50 30
San Angelo 87 70 86 70 86 / 50 50 50 50 40
Junction 89 72 86 72 87 / 40 30 40 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
637 AM CDT FRI SEP 19 2014
.AVIATION...
/12Z TAFS/
Ceilings have come down in many places to less than 2000 ft, but
trying to pin down a prevailing height is akin to playing
whack-a-mole with Mother Nature. In general, ceilings will bounce
around between IFR and MVFR, briefly dropping to less than 500 ft
at times over the next few hours. Visibilities have followed suit
along the I-20 corridor, ranging from 1/4 to 3 miles in the past
hour. Generally improving conditions are anticipated by mid/late
morning, with prevailing VFR conditions anticipated after 16z.
Current convection is expected to weaken this morning, but
additional development is expected this afternoon and tonight. A
VCSH group was appended to all sites excluding KABI this
afternoon. Any cells that develop may produce brief IFR
visibilities and/or MVFR ceilings. Rain chances increase tonight
across the north. Expect a general easterly wind at 10 kts or
less.
Johnson
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT FRI SEP 19 2014/
SHORT TERM...
(Today and tonight)
A split flow pattern persists over the western CONUS with a
relatively deep trough along the West Coast, cut off from the
stronger westerlies over the northern tier. The mid/upper-level
ridge remains in place over the southern Rockies and Plains, but
the remnants of Odile are trapped beneath this ridge, moving
very slowly to the east across NM this morning. Copious tropical
moisture has been advected into the region, as evidenced by the
precipitable water values from the 00z raobs. Both the FWD and DRT
precipitable water values are just below two standard deviations
above climatology. However, the 1.95" PWAT at KMAF is above the
99th percentile. In other words, pretty rare! GPS PWAT data
indicates values over 2.00" east of DRT. Southerly 850mb winds of
15-20 kts will continue to advect this moisture poleward
throughout the day.
Analysis of the wind field hints at a very weak surface boundary
(or trough) extending from northwest to southeast across the
CWA. The RAP Mesoanalysis also indicates a bit of a theta-e
gradient over the southwest zones, in the vicinity of the stronger
convection earlier in the evening. The convection over our neck of
the woods continues to weaken this morning, as does the
precipitation moving into the Permian Basin. However, we should
still see at some activity around through the morning hours.
Despite the abundant cloud cover, temperatures are forecast to
warm into the mid/upper 80s across the southern and eastern zones,
which should promote the development of additional convection by
midday. Most of the models favor the southwest half of the
forecast area for the development of showers and thunderstorms
today, likely focusing a bit farther north, primarily over the
western Big Country and Concho Valley tonight.
The hi-res CAMS are suggesting that convection during the daytime
period will be more cellular in nature, keeping the threat for
flash flooding on the low side. However, tonight, as the low-
level jet begins to intensify, we may see this activity grow
upscale. Given the lower flash flood threat for today, no Flash
Flood Watch will be issued at this time. That said, a watch may be
warranted next shift, focused on the overnight period.
LONG TERM...
(Saturday into Thursday)
Potential for heavy rainfall and flooding will continue this
weekend. Remnants of Odile are expected to push northeast into the
Panhandle and Northwest Texas early Saturday. A cold front then
moves through West Central Texas, from northeast to southwest,
Saturday afternoon and night, acting as a continuing focus for
heavy rainfall.
Both the GFS and NAM models indicate heavy rainfall amounts of 1
to 3 inches in the Big Country and Concho Valley, Saturday and
Saturday night. Locally heavier amounts possible as the tropical
atmosphere will be a efficient rainfall producer. Sunday afternoon,
the heavy rainfall focus moves to the Concho Valley and areas
southwest including Crockett county. This occurs, as more stable air
moves in from the northeast. The main potential for heavy rainfall
then moves southwest of the region Sunday night, with Crockett
county having the best chance of rain. Flash flood watches may be
needed this weekend. Of course, rainfall and runoff will be
extremely beneficial as reservoirs are at extremely low levels and
much West Central Texas is in moderate to extreme drought.
Kept a slight chance of showers on Monday with low/mid level
moisture remaining. Rainfall amounts will be light, if the occur.
A more stable atmosphere remains over the region the rest of the
week, as weak surface high pressure builds in.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 83 69 83 70 85 / 50 50 70 50 30
San Angelo 87 70 86 70 86 / 50 50 50 50 40
Junction 89 72 86 72 87 / 40 30 40 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1139 AM EDT FRI SEP 19 2014
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL SHIFT WEST ACROSS THE MOUNTAINS
TODAY AHEAD OF STRONG HIGH PRESSURE BUILDING IN FROM THE NORTH BY
THIS AFTERNOON. THE HIGH WILL WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE APPALACHIANS TONIGHT INTO SUNDAY KEEPING DRY
WEATHER IN PLACE. A COLD FRONT SHOULD CROSS THE AREA FROM THE
NORTHWEST LATER SUNDAY NIGHT INTO MONDAY FOLLOWED BY COOLER AND
DRIER WEATHER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1139 AM EDT FRIDAY...
MADE SOME QUICK ADJUSTMENTS IN POPS TO EXPAND COVERAGE OF LIGHT
POPS FURTHER NORTH OF HIGHWAY 460 FOR THIS AFTERNOON. ALSO
ADJUSTED TEMPERATURES AND DEW POINTS FOR THIS AFTERNOON INTO
TONIGHT. CUT BACK ON MENTION OF THUNDERSTORMS FOR THIS AFTERNOON.
AS OF 933 AM EDT FRIDAY...
THIS MORNINGS 12Z RNK SOUNDING DISPLAYED PLENTY OF LOW LEVEL
MOISTURE TRAPPED BELOW THE SUBSIDENCE INVERSION WITH A EASTERLY FLOW
FROM SFC UP TO 1KFT. KFCX 88D IMAGES HIGHLIGHTED A FEW SHOWERS THIS
MORNING ESPECIALLY ALONG THE FOOTHILLS OF THE BLUE RIDGE MOUNTAINS.
THIS ACTIVITY IS BEING SUPPORTED BY THE COMBINATION OF A WEAK
SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL THETA-E RIDGING
EAST OF THE BLUE RIDGE. A BLEND OF THE HRRR AND HI RESW-ARW CAPTURED
THIS MORNING POPS.
TWO CHALLENGES FOR THIS AFTERNOON FORECAST ARE HOW FAST/DEEP CAD IS
AND WHATS THE WESTERN EXTENT OF CLOUD COVER. MODEL GUIDANCE STILL
SHOWS AN AXIS OF INSTABILITY ALONG THE I-77 CORRIDOR THIS AFTERNOON
WITH THE WESTERN MOVING SURFACE TROUGH. INCLUDED AN ISOLATED TSRA
MENTION IN NORTHWEST NORTH CAROLINA RIDGES/FOOTHILLS THIS
AFTERNOON WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
TEMPERATURES WILL LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW
DECK AND EASTERLY FLOW. HOWEVER THE FAR WEST COULD ACTUALLY SEE
READINGS PUSH INTO THE 70S GIVEN THE SLOWER WEDGING.
MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES...POPS AND CLOUD COVER
FOR THIS MORNING INTO THIS AFTERNOON.
AS OF 230 AM EDT FRIDAY...
COMBINATION OF A WEAK SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL
THETA-E RIDGING EAST OF THE BLUE RIDGE CONTINUES TO LEAD TO ISOLATED
SLOW MOVING SHOWERS IN SPOTS EARLY THIS MORNING. EXPECT THIS TO PERSIST
A WHILE LONGER PER LATEST HRRR BEFORE THE DEVELOPING WEDGE STARTS TO
ENHANCE FROM NE TO SW BUT A BIT SLOWER THAN EARLIER THOUGHT. THIS
SHOULD START TO PRODUCE SOME SPOTTY -DZ ALONG THE EASTERN SLOPES AS
SHOWERS WANE PER INCREASING STABILITY BUT LOOKS LESS THAN PREVIOUS
GIVEN DRY AIR SAGGING IN FROM THE NORTH OFF MSAS. HOW FAST/DEEP ANY OF
THE LOW CLOUDS CAN BANK IN ALONG THE EASTERN SLOPES KEY TO CLOUDS/TEMPS
THIS AFTERNOON WITH MODELS NOW SLOWER IN INITIALLY PUSHING THE CAD
SOUTH AND WEST. THIS MAY LEAD TO AN AXIS OF MODEST INSTABILITY ESPCLY
ALONG THE I-77 CORRIDOR EARLY THIS AFTERNOON WHERE GUIDANCE REDEVELOPS
SHRA ALONG THE WESTWARD MOVING SURFACE TROUGH. SINCE THIS IN LINE WITH
CONSENSUS...BUMPED UP CHANCE POPS ACROSS NW NC...AND SW VA LATER WHILE
TRIMMING ANY -DZ/-RA TO ISOLATED -SHRA BLUE RIDGE...AND LITTLE MORE
THAN CLOUDS EAST-NE AS BUILDING HIGH PRESSURE START TO ENHANCE INLAND
FROM THE MID ATLANTIC COAST. ALSO INCLUDED AN ISOLATED -TSRA MENTION NW
NC RIDGES/FOOTHILLS WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
OTRW CLOUD COVER AND TEMPS THE MAIN ISSUES ESPCLY BLUE RIDGE WHERE
LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW DECK AND EASTERLY FLOW.
HOWEVER COULD ACTUALLY SEE READINGS PUSH INTO THE 70S FAR WEST GIVEN
THE SLOWER WEDGING...AS WELL AS OVER THE SOUTH/EAST IF CAN GET MORE
SUNNY BREAKS AS MOISTURE STARTS TO DECREASE FROM THE EAST LATE.
SURFACE RIDGING STRENGTHENS FROM THE NE OVERNIGHT HELPING PUSH THE
RESIDUAL AXIS OF MOISTURE FARTHER WEST WHICH SHOULD BRING AN END TO
POPS DURING THE EVENING. BANKED UP LOW LEVEL MOISTURE THOUGH LIKELY TO
REDEVELOP OR PERSIST BLUE RIDGE WHERE LOTS OF LOW CLOUDS/FOG POSSIBLE.
APPEARS AREAS OVER THE EAST/SE FROM HIGHWAY 29 EAST COULD SEE SOME
CLEARING AS MOISTURE GETS PINCHED FARTHER WEST AHEAD OF THE DRIER
EASTERLY FLOW. OTRW VARYING DEGREE OF CLOUDS FROM THE BLUE RIDGE WEST
WITH LOWS MAINLY IN THE 50S PER LATEST SIMILAR MAV/MET MOS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
THE HIGH PRESSURE CENTER THAT WAS OVER NEW ENGLAND WILL MOVE OUT
INTO THE ATLANTIC OVER THE WEEKEND. HOWEVER...THIS RIDGE WILL REMAIN
WEDGE BACK OVER THE MID ATLANTIC AND SOUTHEASTERN STATES INTO
SATURDAY NIGHT. A GULF STREAM DISTURBANCE WILL HELP KEEP THIS WEDGE
IN THE AREA AND ALSO PROVIDE SUBSIDENCE TO KEEP THE FORECAST AREA
DRY SATURDAY. THESE DISTURBANCE WILL HAVE MOST OF ITS RAIN FALLING
ON ITS EASTERN FLANK AS DRY AIR IS ENTRAINED INTO THE WESTERN SIDE.
THIS DISTURBANCE WILL TRACK TO THE NORTHEAST AND WILL REMAIN
OFFSHORE THROUGH THE WEEKEND.
MODELS HAVE SPED UP THE TIMING OF THE NEXT FRONTAL PASSAGE FROM
MONDAY TO SUNDAY. THIS FRONT STILL LOOKS LIKE A TYPICAL FALL FRONTAL
PASSAGE WITH RAIN FALLING ALONG WESTERN SLOPES...LOSING THEIR
INTENSITY MOVING TO THE BLUE RIDGE. THIS PRECIPITATION MAY THEN JUMP
THE FOOTHILLS AS A WEAK LINE OF CONVECTION DEVELOPS OVER THE
PIEDMONT WHERE A LEE TROUGH WILL RESIDE SUNDAY AFTERNOON. THE NAM
AND ECM LOOK SIMILAR WITH KEEPING BULK OF THE RAIN OVER THE
MOUNTAINS. THE GFS PROGRESSIVELY MOVES THE FRONT AND RAINFALL ACROSS
THE ENTIRE FORECAST AREA...DISREGARDING DOWNSLOPE. THE FORECAST DID
NOT DISCREDIT THE GFS...BUT MORE WEIGHT WAS PLACED WITH THE NAM/ECM
FOR SUNDAY.
SATURDAY TEMPERATURES WILL RUN WARMER THAN NORMAL WITH UPPER 70S TO
LOWER 80S. AREAS NOT SEEING RAIN UNTIL LATER IN THE DAY SUNDAY
SHOULD HAVE TEMPERATURES IN THE LOWER TO MID 80S. WESTERN SLOPES
SHOULD HAVE RAIN FALLING BY THE AFTERNOON AND MAY SEE HIGHS IN THE
MID 70S SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 200 PM EDT THURSDAY...
THIS PERIOD IS SHAPING UP TO BE DRY AND SEASONAL. ANOTHER SHORTWAVE
DROPS SOUTHEAST ACROSS THE TN VALLEY MONDAY AND COULD BRING ISOLATED
SHOWERS TO THE ENTIRE AREAS AS FLOW BACKS ALOFT SOME. THEN HIGH
PRESSURE ACROSS THE MIDWEST PUSHES EAST OVER THE MID ATLANTIC
TUE- WED. TEMPS BEHIND THIS SYSTEM EARLY NEXT WEEK WILL COOL DOWN
SOME...BUT NOT LOOKING AS CHILLY AS EARLIER THOUGHT...WITH 8H
TEMPS +10-12C.
HIGHS WILL RUN FROM THE 60S WEST TO 70S EAST...WITH LOWS MAINLY IN
THE 40S...WITH SOME 50S ACROSS THE PIEDMONT.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 650 AM EDT FRIDAY...
CIGS CONTINUE TO SLOWLY LOWER THROUGH MVFR ALONG AND EAST OF THE
BLUE RIDGE EARLY THIS MORNING AS THE WEDGE STARTS TO SPILL
WESTWARD. THIS MAY LEAD TO AN AREA OF IFR CIGS ESPCLY AROUND
KBCB/KROA EAST TO KLYH THIS MORNING INCLUDING PATCHY -RA/-DZ.
OTHER HEAVIER SHOWERS JUST TO THE WEST OF KDAN SHOULD STAY MOSTLY
OUT OF THE KDAN VICINITY WHILE FEEDING NORTH UP TOWARD KROA SO
INCLUDING SOME PREVAILING LIGHT RAIN/DRIZZLE OR VCSH MENTION OVER
THE EAST THIS MORNING. CIGS REMAIN MORE VARIABLE TO THE WEST WITH
MOSTLY VFR TO HIGH END MVFR EXPECTED A WHILE LONGER AT KBLF/KLWB
BEFORE SHOWING SOME IMPROVEMENT LATER THIS MORNING INTO THE
AFTERNOON. SOME ADDED SHOWER DEVELOPMENT POSSIBLE MAINLY MOUNTAINS
THIS AFTERNOON BUT COVERAGE TOO WIDELY SCATTERED TO INCLUDE IN ANY
OF THE TAF LOCATIONS FOR NOW.
DEGREE OF LOW CIGS REMAINS IN QUESTION DURING THE AFTERNOON WITH
POTENTIAL TO SEE OTHER THE WESTERN AND EASTERN PERIMETER SITES
IMPROVE TO VFR WHILE STAYING STUCK IN MVFR OR WORSE ALONG THE BLUE
RIDGE UNTIL LATE. FOR NOW WILL KEEP THE SCENARIO OF SEEING A SLOW
RISE IN CLOUD BASES MOST SPOTS THIS AFTERNOON WITH MOST AT LEAST
GETTING INTO BRIEF VFR. EAST WINDS AT 7-12 KTS TODAY WITH POSSIBLE
LOW END GUSTS IN USUALLY FAVORED SOUTHEAST WIND AREAS...SUCH AS
KBLF.
CIGS MAY LOWER AGAIN THIS EVENING PENDING DEGREE OF
EROSION/COVERAGE HEADING INTO LATE THIS AFTERNOON SO TRENDING
BACK TOWARD MVFR FROM THE BLUE RIDGE EAST EARLY TONIGHT BEFORE
DRYING FROM THE EAST OCCURS. OTRW ANOTHER ROUND OF LOW CIGS IN
FOG AND STRATUS LIKELY LATER TONIGHT INTO EARLY SATURDAY WITH
SOME ADDED PATCHY FOG LIKELY IN THE VALLEYS SUCH AS KLWB/KBCB BY
MORNING.
EXTENDED AVIATION DISCUSSION...
WEDGE SHOULD ERODE FAIRLY QUICKLY SATURDAY IN RESPONSE TO AN
UPSTREAM TROUGH. SOME LOW CLOUDS MAY LINGER THROUGH THE MORNING
ALONG WITH PATCHY FOG...BUT OVERALL VFR CONDITIONS EXPECTED SAT. A
FRONTAL SYSTEM WILL APPROACH SUN WITH -SHRA AND PERHAPS AN ISOLD
TSRA WEST OF THE ALLEGHANY FRONT. INSTABILITY IS QUITE LIMITED AND
SO IS DEEP MOISTURE. WITH A POSSIBLE TROPICAL SYSTEM DEVELOPING
OFF THE COAST AT THE SAME TIME...WE MAY BE IN A STRONG SUBSIDENCE
AREA AND SEE LITTLE MORE THAN -SHRA OR SPRINKLES EAST OF THE
ALLEGHANY FRONT. EXPECT MOSTLY VFR-PERIODS OF MVFR CIGS SUN-EARLY MON
AS THE TROUGH MOVES THROUGH. HIGH PRESSURE BUILDS IN FOR THE FIRST
HALF OF NEXT WEEK WITH DRY NW FLOW. THUS...EXPECT MOSTLY VFR
CONDITIONS THROUGH THE PERIOD WITH LOCAL EARLY MORNING MVFR-IFR
FOG CONDITIONS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH/KK
SHORT TERM...RCS
LONG TERM...WP
AVIATION...JH/KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
934 AM EDT FRI SEP 19 2014
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL SHIFT WEST ACROSS THE MOUNTAINS
TODAY AHEAD OF STRONG HIGH PRESSURE BUILDING IN FROM THE NORTH BY
THIS AFTERNOON. THE HIGH WILL WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE APPALACHIANS TONIGHT INTO SUNDAY KEEPING DRY
WEATHER IN PLACE. A COLD FRONT SHOULD CROSS THE AREA FROM THE
NORTHWEST LATER SUNDAY NIGHT INTO MONDAY FOLLOWED BY COOLER AND
DRIER WEATHER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 933 AM EDT FRIDAY...
THIS MORNINGS 12Z RNK SOUNDING DISPLAYED PLENTY OF LOW LEVEL
MOISTURE TRAPPED BELOW THE SUBSIDENCE INVERSION WITH A EASTERLY FLOW
FROM SFC UP TO 1KFT. KFCX 88D IMAGES HIGHLIGHTED A FEW SHOWERS THIS
MORNING ESPECIALLY ALONG THE FOOTHILLS OF THE BLUE RIDGE MOUNTAINS.
THIS ACTIVITY IS BEING SUPPORTED BY THE COMBINATION OF A WEAK
SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL THETA-E RIDGING
EAST OF THE BLUE RIDGE. A BLEND OF THE HRRR AND HI RESW-ARW CAPTURED
THIS MORNING POPS.
TWO CHALLENGES FOR THIS AFTERNOON FORECAST ARE HOW FAST/DEEP CAD IS
AND WHATS THE WESTERN EXTENT OF CLOUD COVER. MODEL GUIDANCE STILL
SHOWS AN AXIS OF INSTABILITY ALONG THE I-77 CORRIDOR THIS AFTERNOON
WITH THE WESTERN MOVING SURFACE TROUGH. INCLUDED AN ISOLATED TSRA
MENTION IN NORTHWEST NORTH CAROLINA RIDGES/FOOTHILLS THIS
AFTERNOON WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
TEMPERATURES WILL LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW
DECK AND EASTERLY FLOW. HOWEVER THE FAR WEST COULD ACTUALLY SEE
READINGS PUSH INTO THE 70S GIVEN THE SLOWER WEDGING.
MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES...POPS AND CLOUD COVER
FOR THIS MORNING INTO THIS AFTERNOON.
AS OF 230 AM EDT FRIDAY...
COMBINATION OF A WEAK SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL
THETA-E RIDGING EAST OF THE BLUE RIDGE CONTINUES TO LEAD TO ISOLATED
SLOW MOVING SHOWERS IN SPOTS EARLY THIS MORNING. EXPECT THIS TO PERSIST
A WHILE LONGER PER LATEST HRRR BEFORE THE DEVELOPING WEDGE STARTS TO
ENHANCE FROM NE TO SW BUT A BIT SLOWER THAN EARLIER THOUGHT. THIS
SHOULD START TO PRODUCE SOME SPOTTY -DZ ALONG THE EASTERN SLOPES AS
SHOWERS WANE PER INCREASING STABILITY BUT LOOKS LESS THAN PREVIOUS
GIVEN DRY AIR SAGGING IN FROM THE NORTH OFF MSAS. HOW FAST/DEEP ANY OF
THE LOW CLOUDS CAN BANK IN ALONG THE EASTERN SLOPES KEY TO CLOUDS/TEMPS
THIS AFTERNOON WITH MODELS NOW SLOWER IN INITIALLY PUSHING THE CAD
SOUTH AND WEST. THIS MAY LEAD TO AN AXIS OF MODEST INSTABILITY ESPCLY
ALONG THE I-77 CORRIDOR EARLY THIS AFTERNOON WHERE GUIDANCE REDEVELOPS
SHRA ALONG THE WESTWARD MOVING SURFACE TROUGH. SINCE THIS IN LINE WITH
CONSENSUS...BUMPED UP CHANCE POPS ACROSS NW NC...AND SW VA LATER WHILE
TRIMMING ANY -DZ/-RA TO ISOLATED -SHRA BLUE RIDGE...AND LITTLE MORE
THAN CLOUDS EAST-NE AS BUILDING HIGH PRESSURE START TO ENHANCE INLAND
FROM THE MID ATLANTIC COAST. ALSO INCLUDED AN ISOLATED -TSRA MENTION NW
NC RIDGES/FOOTHILLS WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
OTRW CLOUD COVER AND TEMPS THE MAIN ISSUES ESPCLY BLUE RIDGE WHERE
LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW DECK AND EASTERLY FLOW.
HOWEVER COULD ACTUALLY SEE READINGS PUSH INTO THE 70S FAR WEST GIVEN
THE SLOWER WEDGING...AS WELL AS OVER THE SOUTH/EAST IF CAN GET MORE
SUNNY BREAKS AS MOISTURE STARTS TO DECREASE FROM THE EAST LATE.
SURFACE RIDGING STRENGTHENS FROM THE NE OVERNIGHT HELPING PUSH THE
RESIDUAL AXIS OF MOISTURE FARTHER WEST WHICH SHOULD BRING AN END TO
POPS DURING THE EVENING. BANKED UP LOW LEVEL MOISTURE THOUGH LIKELY TO
REDEVELOP OR PERSIST BLUE RIDGE WHERE LOTS OF LOW CLOUDS/FOG POSSIBLE.
APPEARS AREAS OVER THE EAST/SE FROM HIGHWAY 29 EAST COULD SEE SOME
CLEARING AS MOISTURE GETS PINCHED FARTHER WEST AHEAD OF THE DRIER
EASTERLY FLOW. OTRW VARYING DEGREE OF CLOUDS FROM THE BLUE RIDGE WEST
WITH LOWS MAINLY IN THE 50S PER LATEST SIMILAR MAV/MET MOS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
THE HIGH PRESSURE CENTER THAT WAS OVER NEW ENGLAND WILL MOVE OUT
INTO THE ATLANTIC OVER THE WEEKEND. HOWEVER...THIS RIDGE WILL REMAIN
WEDGE BACK OVER THE MID ATLANTIC AND SOUTHEASTERN STATES INTO
SATURDAY NIGHT. A GULF STREAM DISTURBANCE WILL HELP KEEP THIS WEDGE
IN THE AREA AND ALSO PROVIDE SUBSIDENCE TO KEEP THE FORECAST AREA
DRY SATURDAY. THESE DISTURBANCE WILL HAVE MOST OF ITS RAIN FALLING
ON ITS EASTERN FLANK AS DRY AIR IS ENTRAINED INTO THE WESTERN SIDE.
THIS DISTURBANCE WILL TRACK TO THE NORTHEAST AND WILL REMAIN
OFFSHORE THROUGH THE WEEKEND.
MODELS HAVE SPED UP THE TIMING OF THE NEXT FRONTAL PASSAGE FROM
MONDAY TO SUNDAY. THIS FRONT STILL LOOKS LIKE A TYPICAL FALL FRONTAL
PASSAGE WITH RAIN FALLING ALONG WESTERN SLOPES...LOSING THEIR
INTENSITY MOVING TO THE BLUE RIDGE. THIS PRECIPITATION MAY THEN JUMP
THE FOOTHILLS AS A WEAK LINE OF CONVECTION DEVELOPS OVER THE
PIEDMONT WHERE A LEE TROUGH WILL RESIDE SUNDAY AFTERNOON. THE NAM
AND ECM LOOK SIMILAR WITH KEEPING BULK OF THE RAIN OVER THE
MOUNTAINS. THE GFS PROGRESSIVELY MOVES THE FRONT AND RAINFALL ACROSS
THE ENTIRE FORECAST AREA...DISREGARDING DOWNSLOPE. THE FORECAST DID
NOT DISCREDIT THE GFS...BUT MORE WEIGHT WAS PLACED WITH THE NAM/ECM
FOR SUNDAY.
SATURDAY TEMPERATURES WILL RUN WARMER THAN NORMAL WITH UPPER 70S TO
LOWER 80S. AREAS NOT SEEING RAIN UNTIL LATER IN THE DAY SUNDAY
SHOULD HAVE TEMPERATURES IN THE LOWER TO MID 80S. WESTERN SLOPES
SHOULD HAVE RAIN FALLING BY THE AFTERNOON AND MAY SEE HIGHS IN THE
MID 70S SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 200 PM EDT THURSDAY...
THIS PERIOD IS SHAPING UP TO BE DRY AND SEASONAL. ANOTHER SHORTWAVE
DROPS SOUTHEAST ACROSS THE TN VALLEY MONDAY AND COULD BRING ISOLATED
SHOWERS TO THE ENTIRE AREAS AS FLOW BACKS ALOFT SOME. THEN HIGH
PRESSURE ACROSS THE MIDWEST PUSHES EAST OVER THE MID ATLANTIC
TUE- WED. TEMPS BEHIND THIS SYSTEM EARLY NEXT WEEK WILL COOL DOWN
SOME...BUT NOT LOOKING AS CHILLY AS EARLIER THOUGHT...WITH 8H
TEMPS +10-12C.
HIGHS WILL RUN FROM THE 60S WEST TO 70S EAST...WITH LOWS MAINLY IN
THE 40S...WITH SOME 50S ACROSS THE PIEDMONT.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 650 AM EDT FRIDAY...
CIGS CONTINUE TO SLOWLY LOWER THROUGH MVFR ALONG AND EAST OF THE
BLUE RIDGE EARLY THIS MORNING AS THE WEDGE STARTS TO SPILL
WESTWARD. THIS MAY LEAD TO AN AREA OF IFR CIGS ESPCLY AROUND
KBCB/KROA EAST TO KLYH THIS MORNING INCLUDING PATCHY -RA/-DZ.
OTHER HEAVIER SHOWERS JUST TO THE WEST OF KDAN SHOULD STAY MOSTLY
OUT OF THE KDAN VICINITY WHILE FEEDING NORTH UP TOWARD KROA SO
INCLUDING SOME PREVAILING LIGHT RAIN/DRIZZLE OR VCSH MENTION OVER
THE EAST THIS MORNING. CIGS REMAIN MORE VARIABLE TO THE WEST WITH
MOSTLY VFR TO HIGH END MVFR EXPECTED A WHILE LONGER AT KBLF/KLWB
BEFORE SHOWING SOME IMPROVEMENT LATER THIS MORNING INTO THE
AFTERNOON. SOME ADDED SHOWER DEVELOPMENT POSSIBLE MAINLY MOUNTAINS
THIS AFTERNOON BUT COVERAGE TOO WIDELY SCATTERED TO INCLUDE IN ANY
OF THE TAF LOCATIONS FOR NOW.
DEGREE OF LOW CIGS REMAINS IN QUESTION DURING THE AFTERNOON WITH
POTENTIAL TO SEE OTHER THE WESTERN AND EASTERN PERIMETER SITES
IMPROVE TO VFR WHILE STAYING STUCK IN MVFR OR WORSE ALONG THE BLUE
RIDGE UNTIL LATE. FOR NOW WILL KEEP THE SCENARIO OF SEEING A SLOW
RISE IN CLOUD BASES MOST SPOTS THIS AFTERNOON WITH MOST AT LEAST
GETTING INTO BRIEF VFR. EAST WINDS AT 7-12 KTS TODAY WITH POSSIBLE
LOW END GUSTS IN USUALLY FAVORED SOUTHEAST WIND AREAS...SUCH AS
KBLF.
CIGS MAY LOWER AGAIN THIS EVENING PENDING DEGREE OF
EROSION/COVERAGE HEADING INTO LATE THIS AFTERNOON SO TRENDING
BACK TOWARD MVFR FROM THE BLUE RIDGE EAST EARLY TONIGHT BEFORE
DRYING FROM THE EAST OCCURS. OTRW ANOTHER ROUND OF LOW CIGS IN
FOG AND STRATUS LIKELY LATER TONIGHT INTO EARLY SATURDAY WITH
SOME ADDED PATCHY FOG LIKELY IN THE VALLEYS SUCH AS KLWB/KBCB BY
MORNING.
EXTENDED AVIATION DISCUSSION...
WEDGE SHOULD ERODE FAIRLY QUICKLY SATURDAY IN RESPONSE TO AN
UPSTREAM TROUGH. SOME LOW CLOUDS MAY LINGER THROUGH THE MORNING
ALONG WITH PATCHY FOG...BUT OVERALL VFR CONDITIONS EXPECTED SAT. A
FRONTAL SYSTEM WILL APPROACH SUN WITH -SHRA AND PERHAPS AN ISOLD
TSRA WEST OF THE ALLEGHANY FRONT. INSTABILITY IS QUITE LIMITED AND
SO IS DEEP MOISTURE. WITH A POSSIBLE TROPICAL SYSTEM DEVELOPING
OFF THE COAST AT THE SAME TIME...WE MAY BE IN A STRONG SUBSIDENCE
AREA AND SEE LITTLE MORE THAN -SHRA OR SPRINKLES EAST OF THE
ALLEGHANY FRONT. EXPECT MOSTLY VFR-PERIODS OF MVFR CIGS SUN-EARLY MON
AS THE TROUGH MOVES THROUGH. HIGH PRESSURE BUILDS IN FOR THE FIRST
HALF OF NEXT WEEK WITH DRY NW FLOW. THUS...EXPECT MOSTLY VFR
CONDITIONS THROUGH THE PERIOD WITH LOCAL EARLY MORNING MVFR-IFR
FOG CONDITIONS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH/KK
SHORT TERM...RCS
LONG TERM...WP
AVIATION...JH/KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
700 AM EDT FRI SEP 19 2014
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL SHIFT WEST ACROSS THE MOUNTAINS
TODAY AHEAD OF STRONG HIGH PRESSURE BUILDING IN FROM THE NORTH BY
THIS AFTERNOON. THE HIGH WILL WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE APPALACHIANS TONIGHT INTO SUNDAY KEEPING DRY
WEATHER IN PLACE. A COLD FRONT SHOULD CROSS THE AREA FROM THE
NORTHWEST LATER SUNDAY NIGHT INTO MONDAY FOLLOWED BY COOLER AND
DRIER WEATHER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT FRIDAY...
COMBINATION OF A WEAK SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL
THETA-E RIDGING EAST OF THE BLUE RIDGE CONTINUES TO LEAD TO ISOLATED
SLOW MOVING SHOWERS IN SPOTS EARLY THIS MORNING. EXPECT THIS TO PERSIST
A WHILE LONGER PER LATEST HRRR BEFORE THE DEVELOPING WEDGE STARTS TO
ENHANCE FROM NE TO SW BUT A BIT SLOWER THAN EARLIER THOUGHT. THIS
SHOULD START TO PRODUCE SOME SPOTTY -DZ ALONG THE EASTERN SLOPES AS
SHOWERS WANE PER INCREASING STABILITY BUT LOOKS LESS THAN PREVIOUS
GIVEN DRY AIR SAGGING IN FROM THE NORTH OFF MSAS. HOW FAST/DEEP ANY OF
THE LOW CLOUDS CAN BANK IN ALONG THE EASTERN SLOPES KEY TO CLOUDS/TEMPS
THIS AFTERNOON WITH MODELS NOW SLOWER IN INITIALLY PUSHING THE CAD
SOUTH AND WEST. THIS MAY LEAD TO AN AXIS OF MODEST INSTABILITY ESPCLY
ALONG THE I-77 CORRIDOR EARLY THIS AFTERNOON WHERE GUIDANCE REDEVELOPS
SHRA ALONG THE WESTWARD MOVING SURFACE TROUGH. SINCE THIS IN LINE WITH
CONSENSUS...BUMPED UP CHANCE POPS ACROSS NW NC...AND SW VA LATER WHILE
TRIMMING ANY -DZ/-RA TO ISOLATED -SHRA BLUE RIDGE...AND LITTLE MORE
THAN CLOUDS EAST-NE AS BUILDING HIGH PRESSURE START TO ENHANCE INLAND
FROM THE MID ATLANTIC COAST. ALSO INCLUDED AN ISOLATED -TSRA MENTION NW
NC RIDGES/FOOTHILLS WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
OTRW CLOUD COVER AND TEMPS THE MAIN ISSUES ESPCLY BLUE RIDGE WHERE
LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW DECK AND EASTERLY FLOW.
HOWEVER COULD ACTUALLY SEE READINGS PUSH INTO THE 70S FAR WEST GIVEN
THE SLOWER WEDGING...AS WELL AS OVER THE SOUTH/EAST IF CAN GET MORE
SUNNY BREAKS AS MOISTURE STARTS TO DECREASE FROM THE EAST LATE.
SURFACE RIDGING STRENGTHENS FROM THE NE OVERNIGHT HELPING PUSH THE
RESIDUAL AXIS OF MOISTURE FARTHER WEST WHICH SHOULD BRING AN END TO
POPS DURING THE EVENING. BANKED UP LOW LEVEL MOISTURE THOUGH LIKELY TO
REDEVELOP OR PERSIST BLUE RIDGE WHERE LOTS OF LOW CLOUDS/FOG POSSIBLE.
APPEARS AREAS OVER THE EAST/SE FROM HIGHWAY 29 EAST COULD SEE SOME
CLEARING AS MOISTURE GETS PINCHED FARTHER WEST AHEAD OF THE DRIER
EASTERLY FLOW. OTRW VARYING DEGREE OF CLOUDS FROM THE BLUE RIDGE WEST
WITH LOWS MAINLY IN THE 50S PER LATEST SIMILAR MAV/MET MOS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
THE HIGH PRESSURE CENTER THAT WAS OVER NEW ENGLAND WILL MOVE OUT
INTO THE ATLANTIC OVER THE WEEKEND. HOWEVER...THIS RIDGE WILL REMAIN
WEDGE BACK OVER THE MID ATLANTIC AND SOUTHEASTERN STATES INTO
SATURDAY NIGHT. A GULF STREAM DISTURBANCE WILL HELP KEEP THIS WEDGE
IN THE AREA AND ALSO PROVIDE SUBSIDENCE TO KEEP THE FORECAST AREA
DRY SATURDAY. THESE DISTURBANCE WILL HAVE MOST OF ITS RAIN FALLING
ON ITS EASTERN FLANK AS DRY AIR IS ENTRAINED INTO THE WESTERN SIDE.
THIS DISTURBANCE WILL TRACK TO THE NORTHEAST AND WILL REMAIN
OFFSHORE THROUGH THE WEEKEND.
MODELS HAVE SPED UP THE TIMING OF THE NEXT FRONTAL PASSAGE FROM
MONDAY TO SUNDAY. THIS FRONT STILL LOOKS LIKE A TYPICAL FALL FRONTAL
PASSAGE WITH RAIN FALLING ALONG WESTERN SLOPES...LOSING THEIR
INTENSITY MOVING TO THE BLUE RIDGE. THIS PRECIPITATION MAY THEN JUMP
THE FOOTHILLS AS A WEAK LINE OF CONVECTION DEVELOPS OVER THE
PIEDMONT WHERE A LEE TROUGH WILL RESIDE SUNDAY AFTERNOON. THE NAM
AND ECM LOOK SIMILAR WITH KEEPING BULK OF THE RAIN OVER THE
MOUNTAINS. THE GFS PROGRESSIVELY MOVES THE FRONT AND RAINFALL ACROSS
THE ENTIRE FORECAST AREA...DISREGARDING DOWNSLOPE. THE FORECAST DID
NOT DISCREDIT THE GFS...BUT MORE WEIGHT WAS PLACED WITH THE NAM/ECM
FOR SUNDAY.
SATURDAY TEMPERATURES WILL RUN WARMER THAN NORMAL WITH UPPER 70S TO
LOWER 80S. AREAS NOT SEEING RAIN UNTIL LATER IN THE DAY SUNDAY
SHOULD HAVE TEMPERATURES IN THE LOWER TO MID 80S. WESTERN SLOPES
SHOULD HAVE RAIN FALLING BY THE AFTERNOON AND MAY SEE HIGHS IN THE
MID 70S SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 200 PM EDT THURSDAY...
THIS PERIOD IS SHAPING UP TO BE DRY AND SEASONAL. ANOTHER SHORTWAVE
DROPS SOUTHEAST ACROSS THE TN VALLEY MONDAY AND COULD BRING ISOLATED
SHOWERS TO THE ENTIRE AREAS AS FLOW BACKS ALOFT SOME. THEN HIGH
PRESSURE ACROSS THE MIDWEST PUSHES EAST OVER THE MID ATLANTIC
TUE- WED. TEMPS BEHIND THIS SYSTEM EARLY NEXT WEEK WILL COOL DOWN
SOME...BUT NOT LOOKING AS CHILLY AS EARLIER THOUGHT...WITH 8H
TEMPS +10-12C.
HIGHS WILL RUN FROM THE 60S WEST TO 70S EAST...WITH LOWS MAINLY IN
THE 40S...WITH SOME 50S ACROSS THE PIEDMONT.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 650 AM EDT FRIDAY...
CIGS CONTINUE TO SLOWLY LOWER THROUGH MVFR ALONG AND EAST OF THE
BLUE RIDGE EARLY THIS MORNING AS THE WEDGE STARTS TO SPILL
WESTWARD. THIS MAY LEAD TO AN AREA OF IFR CIGS ESPCLY AROUND
KBCB/KROA EAST TO KLYH THIS MORNING INCLUDING PATCHY -RA/-DZ.
OTHER HEAVIER SHOWERS JUST TO THE WEST OF KDAN SHOULD STAY MOSTLY
OUT OF THE KDAN VICINITY WHILE FEEDING NORTH UP TOWARD KROA SO
INCLUDING SOME PREVAILING LIGHT RAIN/DRIZZLE OR VCSH MENTION OVER
THE EAST THIS MORNING. CIGS REMAIN MORE VARIABLE TO THE WEST WITH
MOSTLY VFR TO HIGH END MVFR EXPECTED A WHILE LONGER AT KBLF/KLWB
BEFORE SHOWING SOME IMPROVEMENT LATER THIS MORNING INTO THE
AFTERNOON. SOME ADDED SHOWER DEVELOPMENT POSSIBLE MAINLY MOUNTAINS
THIS AFTERNOON BUT COVERAGE TOO WIDELY SCATTERED TO INCLUDE IN ANY
OF THE TAF LOCATIONS FOR NOW.
DEGREE OF LOW CIGS REMAINS IN QUESTION DURING THE AFTERNOON WITH
POTENTIAL TO SEE OTHER THE WESTERN AND EASTERN PERIMETER SITES
IMPROVE TO VFR WHILE STAYING STUCK IN MVFR OR WORSE ALONG THE BLUE
RIDGE UNTIL LATE. FOR NOW WILL KEEP THE SCENARIO OF SEEING A SLOW
RISE IN CLOUD BASES MOST SPOTS THIS AFTERNOON WITH MOST AT LEAST
GETTING INTO BRIEF VFR. EAST WINDS AT 7-12 KTS TODAY WITH POSSIBLE
LOW END GUSTS IN USUALLY FAVORED SOUTHEAST WIND AREAS...SUCH AS
KBLF.
CIGS MAY LOWER AGAIN THIS EVENING PENDING DEGREE OF
EROSION/COVERAGE HEADING INTO LATE THIS AFTERNOON SO TRENDING
BACK TOWARD MVFR FROM THE BLUE RIDGE EAST EARLY TONIGHT BEFORE
DRYING FROM THE EAST OCCURS. OTRW ANOTHER ROUND OF LOW CIGS IN
FOG AND STRATUS LIKELY LATER TONIGHT INTO EARLY SATURDAY WITH
SOME ADDED PATCHY FOG LIKELY IN THE VALLEYS SUCH AS KLWB/KBCB BY
MORNING.
EXTENDED AVIATION DISCUSSION...
WEDGE SHOULD ERODE FAIRLY QUICKLY SATURDAY IN RESPONSE TO AN
UPSTREAM TROUGH. SOME LOW CLOUDS MAY LINGER THROUGH THE MORNING
ALONG WITH PATCHY FOG...BUT OVERALL VFR CONDITIONS EXPECTED SAT. A
FRONTAL SYSTEM WILL APPROACH SUN WITH -SHRA AND PERHAPS AN ISOLD
TSRA WEST OF THE ALLEGHANY FRONT. INSTABILITY IS QUITE LIMITED AND
SO IS DEEP MOISTURE. WITH A POSSIBLE TROPICAL SYSTEM DEVELOPING
OFF THE COAST AT THE SAME TIME...WE MAY BE IN A STRONG SUBSIDENCE
AREA AND SEE LITTLE MORE THAN -SHRA OR SPRINKLES EAST OF THE
ALLEGHANY FRONT. EXPECT MOSTLY VFR-PERIODS OF MVFR CIGS SUN-EARLY MON
AS THE TROUGH MOVES THROUGH. HIGH PRESSURE BUILDS IN FOR THE FIRST
HALF OF NEXT WEEK WITH DRY NW FLOW. THUS...EXPECT MOSTLY VFR
CONDITIONS THROUGH THE PERIOD WITH LOCAL EARLY MORNING MVFR-IFR
FOG CONDITIONS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...WP
AVIATION...JH/KK/RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
649 AM CDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 219 AM CDT FRI SEP 19 2014
FORECAST CONCERNS INCLUDE PRECIPITATION CHANCES THROUGH
TONIGHT...SEVERE WEATHER POTENTIAL TONIGHT...AND WINDS THIS
AFTERNOON.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE CENTRAL PLAINS WHILE A FAST SEMI-ZONAL FLOW
WAS PRESENT ALONG THE U.S./CANADIAN BORDER. WITHIN THIS FLOW...A
SHORTWAVE TROUGH WAS OVER SOUTHERN SASKATCHEWAN AND ADJACENT
MONTANA. THIS TROUGH HAS BEEN RESPONSIBLE FOR... 1. PLENTY OF
MID/HIGH CLOUDS DOWNSTREAM OVER THE DAKOTAS...SOME OF WHICH WERE
PRODUCING SHOWERS AND A FEW THUNDERSTORMS. 2. PULLING MORE HUMID AIR
THROUGH THE DAKOTAS ON A 20-40 KT JET AT 925MB WITH SURFACE
DEWPOINTS IN THE 60S...AS WELL AS PRECIPITABLE WATER OF 1-1.5
INCHES. FINALLY 3...DEVELOPING AN UNSEASONABLY WARM...CAPPED AIRMASS
OVER SOUTH DAKOTA CHARACTERIZED BY 850MB TEMPS OF 18-24C AND 700MB
TEMPS OF 10-13C. OVER THE FORECAST AREA...MUCH COOLER AND DRIER AIR
EXISTS WITH 850MB TEMPS AROUND 10C AND PRECIPITABLE WATER AROUND 0.5
INCH. A WARM FRONT SEPARATES THE DIVISION OF AIRMASSES OVER WESTERN
MN...WHICH ISENTROPIC LIFT/MID-LEVEL MOISTURE TRANSPORT INTO THE
FRONT HAS LED TO MID CLOUDS IN MN. NOTHING YET FALLING OUT OF
THESE...THOUGH.
MODELS ARE IN AGREEMENT TRACKING THE SHORTWAVE TROUGH OVER
SASKATCHEWAN AND MONTANA INTO THE DAKOTAS BY 00Z. WHAT THIS DOES IS
HELP CONTINUE A WARM ADVECTION REGIME DOWNSTREAM INTO THE FORECAST
AREA. THE BIG PLUME OF WARM 700MB AND 850MB AIR OVER SOUTH DAKOTA
STREAMS EAST-NORTHEAST ACROSS THE FORECAST AREA...AS WELL AS OVER
CENTRAL MN AND NORTHWEST WI...EFFECTIVELY PUTTING A NICE CAP IN
PLACE. PRIOR TO THIS CAP ARRIVING THIS AFTERNOON...A FEW DAYS AGO IT
APPEARED THAT THE ISENTROPIC LIFT AND MID-LEVEL MOISTURE TRANSPORT
WOULD BE ENOUGH TO INITIATE CONVECTION. HOWEVER...THAT DOES NOT
APPEAR TO BE THE CASE ANYMORE WITH MOST MODELS SUGGESTING A DRY DAY
TODAY. HAVE STILL LEFT SOME LOW CHANCES IN TAYLOR AND CLARK COUNTIES
FOR THE LATE AFTERNOON...DUE TO ACTIVITY OVER NORTH DAKOTA PROGGED
TO MARCH EAST ACROSS NORTHERN WI. NOW THE 19.00Z GFS DOES PRODUCE
SOME PRECIP FROM EAU TO LSE DURING THE EARLY AFTERNOON HOURS...BUT
APPEARS TO BE THE LONE MODEL OUT. SOUNDINGS TOO FROM THE GFS AT LSE
LOOK ODD FOR PRODUCING RAIN...HAVING JUST SOME SMALL LAYER OF
SATURATION BELOW THE CAP.
PRESSURE GRADIENT EXPECTED TO BE QUITE TIGHT TODAY OVER THE FORECAST
AREA AHEAD OF A COLD FRONT CROSSING THE DAKOTAS. WITH 850MB WINDS
INCREASING THIS AFTERNOON TO 35-50 KT SOUTHEAST TO NORTHWEST ACROSS
THE FORECAST AREA...AND DAYTIME MIXING...WE COULD SEE GUSTS UPWARDS
OF 25-35 KT. HIGHEST GUSTS ARE ANTICIPATED OVER HIGHER TERRAIN OF
SOUTHEAST MN. THESE WOULD BE JUST UNDER ADVISORY CRITERIA. REGARDING
THE AFOREMENTIONED MIXING...PERIODS OF SUN PLUS 925MB TEMPS CLIMBING
TO 16-20C BY 00Z...MOST LOCATIONS OUTSIDE OF TAYLOR/CLARK SHOULD SEE
HIGHS IN THE 70S.
FOR TONIGHT...MODELS BRING THE SHORTWAVE TROUGH INTO MN AND NORTHERN
WI...DRAGGING THE SURFACE COLD FRONT THROUGH THE NORTHWEST HALF OF
THE FORECAST AREA BY 12Z SAT. ALL MODELS SUGGEST THAT THE DPVA AHEAD
OF THE TROUGH WILL HELP COOL THE CAP...AND FORCE SOME CONVECTION TO
DEVELOP. APPEARS MUCH OF THE CONVECTION WILL BE ROOTED ABOVE THE
BOUNDARY LAYER WITH PARCELS BEING LIFTED BETWEEN 850-900MB...OR
ABOUT 1 KM ABOVE THE GROUND. CAPE LIFTED FROM THIS LEVEL RANGES FROM
1500-2000 J/KG WHILE THE 1-6KM SHEAR IS ONLY 10-15 KT. THAT SHEAR IS
CERTAINLY UNFAVORABLE FOR SEVERE. IF FOR SOME REASON THE PARCELS CAN
GET ROOTED BELOW 1 KM...THE 0-3KM SHEAR IS 35-40 KT...MUCH MORE
FAVORABLE. GIVEN THAT EQUILIBRIUM LEVELS ARE UP NEAR 40000 FT...CAN
NOT RULE OUT AN ISOLATED SEVERE STORM CAPABLE OF HAIL/WIND...WHICH
LOOKS MOST LIKELY SOMETIME IN THE LATE EVENING OR EARLY MORNING.
CONSIDERED RAISING PRECIPITATION CHANCES UP TO 60...BUT BOTH THE
19.00Z NSSL WRF-ARW AND NCEP HIRES-ARW SUGGEST ANYWHERE FROM
ISOLATED-SCATTERED COVERAGE. APPEARS THE LACK OF DECENT CONVERGENCE
BETWEEN 900-700MB IS THE CAUSE. ALL MODELS DO AGREE THAT THE BULK OF
THE CONVECTION SHOULD BE EXITING THE AREA BY 12Z. IT SHOULD
GENERALLY BE A WARM NIGHT UNTIL THE FRONTAL PASSAGE DUE TO A BREEZY
WIND AND HIGHER DEWPOINTS. AFTER FROPA...IT LOOKS LIKE A LOW STRATUS
DECK MAY FORM AS MODELS SUGGEST A SHALLOW COOL AIRMASS MOVING IN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 219 AM CDT FRI SEP 19 2014
COMPARED TO THE SHORT TERM PERIOD...GENERALLY QUIET WEATHER
DOMINATES THE LONG TERM. THERE ARE A FEW TIME PERIODS TO FOCUS ON.
GENERAL MODELS CONSENSUS IS FOR THE SHORTWAVE TROUGH TO MOVE
INTO/OVER THE FORECAST AREA BY 18Z SATURDAY...PUSHING THE COLD FRONT
ALL THE WAY THROUGH. IT APPEARS ANY CONVECTION RE-FIRING ALONG THE
COLD FRONT ON SATURDAY WILL OCCUR SOUTHEAST OF THE FORECAST AREA.
STILL MAINTAINED SOME LOW PRECIPITATION CHANCES OVER THE SOUTHEAST
HALF OF THE FORECAST AREA IN THE MORNING...THOUGH...AS WE WAIT FOR
THE SHORTWAVE TROUGH TO FULLY MOVE IN. THEN THERE SHOULD BE A
BREAK...AHEAD OF A FAIRLY POTENT SHORTWAVE DROPPING IN ON THE BACK
SIDE OF THE SHORTWAVE TROUGH OVER MN BY 00Z SUNDAY. THIS SHORTWAVE
DIVES THROUGH THE FORECAST AREA SATURDAY NIGHT. THE POTENT NATURE
COULD BE ENOUGH TO BRING SOME SHOWERS ACROSS THE FORECAST AREA...BUT
THERE IS SOME UNCERTAINTY ON MOISTURE AVAILABILITY. A LOT OF MODELS
HAVE ANY PRECIPITATION WITH THE SHORTWAVE DIMINISHING BEFORE IT
COMES INTO THE FORECAST AREA...OR MAYBE HOLDING ONTO IT FOR I-94.
SOME COLD POOL SHOWERS...ENHANCED BY A SECONDARY COLD FRONT DROPPING
THROUGH THE FORECAST AREA...COULD OCCUR ON SUNDAY ALONG AND NORTH OF
I-94. OTHERWISE...SUNDAY LOOKS SIGNIFICANTLY COOLER COMPARED TO
SATURDAY WITH 925MB TEMPS FALLING FROM 18-21C AT 00Z SUNDAY TO 11-
13C AT 18Z SUNDAY.
SUNDAY NIGHT THROUGH TUESDAY CONTINUES TO BE DOMINATED BY HIGH
PRESSURE AT THE SURFACE...WHILE VERY STRONG UPPER RIDGING MARCHES
FROM THE NORTHWESTERN U.S. INTO THE REGION. THIS SETUP WILL FAVOR A
COOL NIGHT WITH POTENTIAL FOR VALLEY FOG SUNDAY NIGHT...FOLLOWED BY
GRADUAL AIRMASS MODIFICATION AND WARMING THROUGH TUESDAY.
FOR WEDNESDAY AND THURSDAY...AN UPPER TROUGH CURRENTLY SITTING OFF
THE CALIFORNIA COAST IS PROGGED TO LIFT THROUGH THE REGION. TOUGH TO
SAY HOW MUCH MOISTURE THIS FEATURE WILL HAVE WITH IT AT THIS
TIME...AND IF ITS TRACK ENDS UP GOING THROUGH THE REGION OR STAYING
OFF TO THE WEST. THEREFORE...FOR NOW THE FORECAST JUST HAS SOME LOW
PRECIPITATION CHANCES WITH IT. TEMPERATURES COULD GET KNOCKED DOWN A
LITTLE BIT WITH THIS UPPER TROUGH MOVING THROUGH.
BEYOND THURSDAY...GOOD MODEL RUN TO RUN CONSISTENCY EXISTS THAT
THE UPPER TROUGH WILL LIFT OUT OF THE REGION...IN RESPONSE TO STRONG
UPPER RIDGING BUILDS OVER THE EASTERN TWO THIRDS OF THE COUNTRY
GOING INTO NEXT WEEKEND. THIS UPPER RIDGING SHOULD BRING DRY
CONDITIONS ALONG WITH ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 648 AM CDT FRI SEP 19 2014
THE SURFACE PRESSURE GRADIENT WILL CONTINUE TO GRADUALLY TIGHTEN
THIS MORNING. AS THIS OCCURS...THE SUSTAINED SOUTH WINDS WILL
CLIMB INTO THE 15 TO 25 KNOT RANGE. IN ADDITION WITH DIURNAL
HEATING...THE WINDS WILL GUST INTO THE 25 TO 30 KNOT RANGE FROM
19.16Z AND 20.01Z.
A COLD FRONT WILL PRODUCE SCATTERED SHOWERS AND STORMS AT KRST
BETWEEN 20.03Z AND 20.08Z...AND AT KLSE BETWEEN 20.05Z AND 20.09Z.
THE THUNDERSTORMS MAY REDUCE VISIBILITIES TO LESS THAN A MILE AT
TIMES. HOWEVER THE TIMING OF THIS IS TOO UNCERTAIN TO INCLUDE IN
THE TAFS AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1040 AM PDT FRI SEP 19 2014
.SYNOPSIS...
WEAK UPPER LEVEL LOW PRESSURE WILL BRING BELOW NORMAL TEMPERATURES
TO MUCH OF THE REGION THROUGH THE WEEKEND. TEMPERATURES WILL LIKELY
WARM TO NEAR NORMAL EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
HIGH PRESSURE BRIEFLY RETURNS. ANOTHER TROUGH OF LOW PRESSURE MAY
BRING A COOLING TREND FOR THE SECOND HALF OF NEXT WEEK.
&&
.SHORT TERM (REST OF TODAY-SUN)...WITH THE CLOSED UPPER LOW
CONTINUING TO SPIN ITS WAY DOWN THE CENTRAL COAST...A WEAK ONSHORE
GRADIENT AND A MODERATE TO STRONG EDDY...THERE`S BEEN QUITE A BIT OF
STRATUS COVERAGE INLAND THIS MORNING WITH AROUND A 3K FT MARINE
LAYER. COOLING TREND ALSO ON TRACK WITH MANY LOCATIONS AS MUCH AS 10
DEG COOLER THAN YESTERDAY MORNING`S READINGS AT THIS TIME. SO COOLER
HIGH TEMPS FORECAST FOR TODAY LOOK GOOD. VISIBLE LOOP SHOWING
STRATUS DECK IS TRYING TO THIN OUT SO EXPECT MOST AREAS TO CLEAR OUT
BY LATE MORNING BUT POSSIBLY NOT BY EARLY AFTERNOON. WILL TWEAK THE
FORECAST FOR LESS CLOUDS THIS AFTERNOON OVER ALL BUT THE VENTURA AND
SBA COUNTY MOUNTAINS WHERE THERE STILL APPEARS TO BE AT LEAST A
SLIGHT CHANCE OF CONVECTION THIS AFTERNOON. LATEST MODEL CONVECTIVE
PARAMETERS SHOW SOME INSTABILITY WITH LIFTED INDICIES AROUND -3.0
CENTERED OVER THE VTU COUNTY MOUNTAINS NORTH INTO SBA MOUNTAINS...A
POOL OF LOW TO MID LEVEL MOISTURE INDICATED BY A BROAD AREA OF 850
DEWPOINTS BETWEEN 10 AND 12C...AND FINALLY SOME DYNAMIC HELP FROM A
FAVORABLE POSITION OF THE UPPER LOW. WHAT DOES FORM SHOULD BE MOVING
FAST ENOUGH TO LIMIT ANY FLASH FLOODING. OVERALL WILL LEAVE TRW
CHANCES IN THE FORECAST FOR THIS AFTERNOON OVER THE AREAS OF VTU AND
SBA COUNTY MOUNTAINS. CONVECTIVE INDICATORS HINT AT POSSIBLE
ACTIVITY OVER THE LA COUNTY MOUNTAINS BUT WILL KEEP CHANCES OUT FOR
NOW AND MONITOR THROUGH THE AFTERNOON.
WILL LIKELY GO AHEAD AND ADD TRW CHANCES FOR SATURDAY AFTERNOON IN
THIS AFTERNOON`S UPDATE. MOISTURE APPEARS TO BE A LITTLE MORE
LIMITED...BUT MODELS FORECASTING THE UPPER LOW TO EJECT OUT OVER THE
AREA TOMORROW...SO MOISTURE DEFICIENCY SHOULD BE MADE UP FOR BY
BETTER DYNAMICS. AT FIRST GLANCE BELIEVE BETTER CHANCE WILL AGAIN BE
OVER VTU AND SBA COUNTY MOUNTAINS DUE TO THAT AREA`S RELATIVELY
BETTER MOISTURE AVAILABILITY...BUT DYNAMICS APPEAR BETTER SOUTH OVER
LA COUNTY. WILL TAKE A CLOSER LOOK THIS AFTERNOON. THE MORNING`S
MARINE LAYER STRATUS WILL BE A TRICKY FORECAST SO PERSISTENCE LOOKS
TO BE THE BEST OPTION.
***FROM PREVIOUS DISCUSSION***
LATEST FOG PRODUCT IMAGERY INDICATED PLENTY OF LOW LEVEL MOISTURE
LINGERING ACROSS COAST AND VALLEYS N OF POINT CONCEPTION...WHILE LOW
CLOUDS WERE MORE RANDOM IN NATURE FOR AREAS SOUTH OF POINT
CONCEPTION. LOW CLOUDS SHOULD FILL IN ACROSS COAST AND VALLEYS OF
LOS ANGELES...VENTURA AND SANTA BARBARA COUNTIES BY DAWN. THERE WILL
BE ENOUGH LOW LEVEL LIFT TO CAUSE SOME PATCHY DRIZZLE TO OCCUR JUST
ABOUT ANYWHERE WEST OF THE MOUNTAINS THIS MORNING. LATEST ACARS
SOUNDING NEAR LAX SHOWED A VERY WEAK INVERSION IN PLACE WHICH MAKES
SENSE WHY CLOUDS ARE NOT MORE UNIFORM S OF POINT CONCEPTION THIS
MORNING. WIND PATTERNS ARE INTERESTING THIS MORNING. OVER THE
COASTAL AREAS INTO LA COUNTY THE FLOW IS MOSTLY CYCLONIC NW BECOMING
SW OVER LA COUNTY. HOWEVER...NORTHERLY WINDS WERE OCCURRING OVER THE
MOUNTAINS AND SAN JOAQUIN VALLEY. THIS NORTHERLY FLOW WAS CAUSING
ADDITIONAL CLOUDS TO PILE UP ALONG THE NORTHERN SLOPES OF THE LOCAL
MOUNTAINS THIS MORNING INCLUDING THE I-5 CORRIDOR.
SYNOPTICALLY...A CLOSED 578 DM UPPER LOW CURRENTLY OFF THE CENTRAL
COAST WILL DRIFT SLOWLY SOUTH JUST WEST OF POINT CONCEPTION BY THIS
AFTERNOON. THE PROXIMITY OF THE UPPER LOW WILL ALLOW FAVORABLE COOL
CYCLONIC FLOW OVER MOST OF LOS ANGELES...VENTURA AND SANTA BARBARA
COUNTIES TODAY. THERE IS NOT MUCH IN THE WAY OF MOISTURE ASSOCIATED
WITH THE UPPER LOW...BUT THERE WILL BE PLENTY LOW CLOUDS LINGERING
ACROSS THE COAST AND VALLEYS THROUGH THIS MORNING AND INTO THE
AFTERNOON ACROSS MOST COASTAL AREAS. RAP AND NAM-WRF MODELS
INDICATED THAT THERE WOULD BE ENOUGH INSTABILITY AND LIMITED MID
LEVEL MOISTURE TO WARRANT A SLIGHT CHANCE FOR SHOWERS OR
THUNDERSTORMS TO DEVELOP OVER THE VENTURA COUNTY MOUNTAINS AS WELL
AS PORTIONS OF THE SANTA BARBARA COUNTY MOUNTAINS THIS AFTERNOON AND
EVENING HOURS. TEMPERATURES WILL CONTINUE TO TREND COOLER THROUGH
SATURDAY AS THE UPPER LOW MOVES DIRECTLY OVER SBA/VENTURA
COUNTIES SATURDAY AFTERNOON. THERE IS NOT MUCH DIFFLUENCE ASSOCIATED
WITH THE UPPER LOW FOR SATURDAY AND MODELS WERE NOT PICKING UP ON
ANY ADDITIONAL MOISTURE OR CONVECTIVE PARAMETERS ACROSS THE LOCAL
MOUNTAINS. WILL LET LATER SHIFTS LOOK CLOSER TO SEE IF SLIGHT CHANCE
POPS WILL BE NEEDED FOR SAT IN THE LOCAL MTNS ONCE AGAIN.EXPECT HIGH
TEMPS TO BE NEAR OR JUST BELOW NORMAL TODAY AND SATURDAY.
BY SUNDAY...THE UPPER LOW WILL FILL IN AND MOVE NE INTO NEVADA
ALLOWING HEIGHTS AND THICKNESS LVLS TO RISE. THERE WILL BE NIGHT
THROUGH MORNING LOW CLOUDS BUT A QUICKER BURNOFF AND HIGH TEMPS WILL
BE A FEW DEGREES HIGHER...ESPECIALLY ACROSS INTERIOR
LOCATIONS...WITH WARMEST VALLEY LOCATIONS IN THE MID 80S...AND MID
TO UPPER 70S ALONG THE COAST.
.LONG TERM (MON-THU)...BOTH GFS AND ECMWF STAY IN PRETTY GOOD
AGREEMENT OVER THE LONG TERM PERIOD. A WEAK RIDGE WILL BEGIN TO
BUILD OVER BAJA CALIFORNIA WHILE MUCH OF NORTHERN CALIFORNIA REMAIN
UNDER A BROAD UPPER TROUGH THROUGH WED. EXPECT NIGHT THROUGH MORNING
LOW CLOUDS FOR COASTAL AREAS AND POSSIBLY SOME COASTAL VALLEYS
THROUGH WED MORNING. TEMPS WILL CONTINUE TO REBOUND MONDAY AND
TUESDAY WITH HIGHS REACHING THE LOWER 90S ACROSS WARMEST VALLEY
LOCATIONS. FOR WED AND THU...A BROAD UPPER TROUGH WILL BEGIN TO DIG
FARTHER SOUTH. THE GFS IS SHOWING A SHARPER TROUGH WHICH WOULD MEAN
MORE SIGNIFICANT COOLING BY THURSDAY...WHERE THE EUROPEAN MODEL IS
LESS PRONOUNCED. AT THIS POINT HAVE TRENDED HIGH TEMPS DOWN SLIGHTLY
FOR WED...WITH A FEW MORE DEGREES OF COOLING FOR THURSDAY TO
SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...19/1800Z.
MID/UPPER LEVEL LOW PRESSURE SYSTEM CENTERED SOUTHWEST OF POINT
CONCEPTION WILL SHIFT NORTHEAST. UPPER LEVEL STRONG SOUTHWEST WINDS
WILL BECOME MODERATE SOUTHWEST BY 21/00Z WHILE MID LEVEL LIGHT
SOUTHEAST WINDS BECOME MODERATE SOUTHEAST AFTER 20/08Z OVER THE
AREA. ISOLATED THUNDERSTORMS BETWEEN 19/23-20/03Z OVER VENTURA AND
SANTA BARBARA COUNTY MOUNTAINS WITH TOPS 45KFT AND STORMS WILL MOVE
NORTH APPROXIMATELY 15KT. LOW LEVEL CLOUD TOPS WERE APPROXIMATELY
3KFT ALONG THE CENTRAL COAST TO 3KFT OVER THE BIGHT. THE CAPPING
INVERSION WAS WEAK AND WILL LIKELY DIFFER LITTLE SATURDAY MORNING
FROM THIS MORNING. THE CLOUD FIELD WAS DISORGANIZED...BROKEN OVER
THE BIGHT AND SCATTERED ON THE CENTRAL COAST AND WILL LIKELY
CONTINUE DISORGANIZED SATURDAY MORNING. WEAK ONSHORE PRESSURE
GRADIENT BECOMING MODERATE ONSHORE AFTER 20/19Z.
KLAX...LIKELY SCATTERED 035 BY 19/20Z. CHANCE CIGS 015 BETWEEN
20/09-20/17Z AND CIGS 027 BETWEEN 20/17-20/19Z.
KBUR...LIKELY SCATTERED 025 BY 19/20Z. CHANCE CIGS 017 BY 20/10Z.
VIRTUALLY CERTAIN - 95-100%
VERY LIKELY - 80-95%
LIKELY - 60-80%
CHANCE - 30-60%
VERY UNLIKELY - 20% OR LESS
&&
.MARINE...19/900 AM.
THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS IN THE VICINITY OF
THE NORTHERN CHANNEL ISLANDS WILL DEVELOP THIS AFTERNOON AND END
LATE TONIGHT. THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL
REDEVELOP EACH EVENING AND EXIST SEVERAL HOURS EACH DAY
SUNDAY THROUGH TUESDAY. THERE IS A CHANCE THE NORTHWEST WINDS WILL
INCREASE TO GALES THURSDAY AFTERNOON IN THE VICINITY OF THE NORTHERN
ISLANDS TO SAN NICOLAS ISLAND. A MIXED WEST NORTHWEST SWELL AND
SOUTH SOUTHWEST SWELL WILL CONTINUE TO SUBSIDE AND LINGER THROUGH
SATURDAY. SWELLS ORIGINATING FROM A FAST MOVING AND SHORT LIVED GULF
OF ALASKA STORM ON THURSDAY ARE EXPECTED TO ARRIVE SUNDAY FROM
295-305. THERE IS A CHANCE THE SWELL WILL PEAK SUNDAY NIGHT AND
LINGER THROUGH TUESDAY. A LOW PRESSURE SYSTEM IS LIKELY TO DEVELOP
OVER THE EASTERN PACIFIC NEXT WEEK MONDAY THROUGH TUESDAY AND
GUIDANCE HAD TRENDED DEEPER WITH THE SYSTEM. SWELLS GENERATED BY
STORM FORCE WINDS ARE EXPECTED TO ARRIVE FROM 300-310 DEGREES
WEDNESDAY EVENING AND PEAK THURSDAY AND LINGER THROUGH FRIDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...JACKSON/KAPLAN
AVIATION/MARINE...30
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
950 AM PDT FRI SEP 19 2014
.SYNOPSIS...
WEAK UPPER LEVEL LOW PRESSURE WILL BRING BELOW NORMAL TEMPERATURES
TO MUCH OF THE REGION THROUGH THE WEEKEND. TEMPERATURES WILL LIKELY
WARM TO NEAR NORMAL EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
HIGH PRESSURE BRIEFLY RETURNS. ANOTHER TROUGH OF LOW PRESSURE MAY
BRING A COOLING TREND FOR THE SECOND HALF OF NEXT WEEK.
&&
.SHORT TERM (REST OF TODAY-SUN)...WITH THE CLOSED UPPER LOW
CONTINUING TO SPIN ITS WAY DOWN THE CENTRAL COAST...A WEAK ONSHORE
GRADIENT AND A MODERATE TO STRONG EDDY...THERE`S BEEN QUITE A BIT OF
STRATUS COVERAGE INLAND THIS MORNING WITH AROUND A 3K FT MARINE
LAYER. COOLING TREND ALSO ON TRACK WITH MANY LOCATIONS AS MUCH AS 10
DEG COOLER THAN YESTERDAY MORNING`S READINGS AT THIS TIME. SO COOLER
HIGH TEMPS FORECAST FOR TODAY LOOK GOOD. VISIBLE LOOP SHOWING
STRATUS DECK IS TRYING TO THIN OUT SO EXPECT MOST AREAS TO CLEAR OUT
BY LATE MORNING BUT POSSIBLY NOT BY EARLY AFTERNOON. WILL TWEAK THE
FORECAST FOR LESS CLOUDS THIS AFTERNOON OVER ALL BUT THE VENTURA AND
SBA COUNTY MOUNTAINS WHERE THERE STILL APPEARS TO BE AT LEAST A
SLIGHT CHANCE OF CONVECTION THIS AFTERNOON. LATEST MODEL CONVECTIVE
PARAMETERS SHOW SOME INSTABILITY WITH LIFTED INDICIES AROUND -3.0
CENTERED OVER THE VTU COUNTY MOUNTAINS NORTH INTO SBA MOUNTAINS...A
POOL OF LOW TO MID LEVEL MOISTURE INDICATED BY A BROAD AREA OF 850
DEWPOINTS BETWEEN 10 AND 12C...AND FINALLY SOME DYNAMIC HELP FROM A
FAVORABLE POSITION OF THE UPPER LOW. WHAT DOES FORM SHOULD BE MOVING
FAST ENOUGH TO LIMIT ANY FLASH FLOODING. OVERALL WILL LEAVE TRW
CHANCES IN THE FORECAST FOR THIS AFTERNOON OVER THE AREAS OF VTU AND
SBA COUNTY MOUNTAINS. CONVECTIVE INDICATORS HINT AT POSSIBLE
ACTIVITY OVER THE LA COUNTY MOUNTAINS BUT WILL KEEP CHANCES OUT FOR
NOW AND MONITOR THROUGH THE AFTERNOON.
WILL LIKELY GO AHEAD AND ADD TRW CHANCES FOR SATURDAY AFTERNOON IN
THIS AFTERNOON`S UPDATE. MOISTURE APPEARS TO BE A LITTLE MORE
LIMITED...BUT MODELS FORECASTING THE UPPER LOW TO EJECT OUT OVER THE
AREA TOMORROW...SO MOISTURE DEFICIENCY SHOULD BE MADE UP FOR BY
BETTER DYNAMICS. AT FIRST GLANCE BELIEVE BETTER CHANCE WILL AGAIN BE
OVER VTU AND SBA COUNTY MOUNTAINS DUE TO THAT AREA`S RELATIVELY
BETTER MOISTURE AVAILABILITY...BUT DYNAMICS APPEAR BETTER SOUTH OVER
LA COUNTY. WILL TAKE A CLOSER LOOK THIS AFTERNOON. THE MORNING`S
MARINE LAYER STRATUS WILL BE A TRICKY FORECAST SO PERSISTENCE LOOKS
TO BE THE BEST OPTION.
***FROM PREVIOUS DISCUSSION***
LATEST FOG PRODUCT IMAGERY INDICATED PLENTY OF LOW LEVEL MOISTURE
LINGERING ACROSS COAST AND VALLEYS N OF POINT CONCEPTION...WHILE LOW
CLOUDS WERE MORE RANDOM IN NATURE FOR AREAS SOUTH OF POINT
CONCEPTION. LOW CLOUDS SHOULD FILL IN ACROSS COAST AND VALLEYS OF
LOS ANGELES...VENTURA AND SANTA BARBARA COUNTIES BY DAWN. THERE WILL
BE ENOUGH LOW LEVEL LIFT TO CAUSE SOME PATCHY DRIZZLE TO OCCUR JUST
ABOUT ANYWHERE WEST OF THE MOUNTAINS THIS MORNING. LATEST ACARS
SOUNDING NEAR LAX SHOWED A VERY WEAK INVERSION IN PLACE WHICH MAKES
SENSE WHY CLOUDS ARE NOT MORE UNIFORM S OF POINT CONCEPTION THIS
MORNING. WIND PATTERNS ARE INTERESTING THIS MORNING. OVER THE
COASTAL AREAS INTO LA COUNTY THE FLOW IS MOSTLY CYCLONIC NW BECOMING
SW OVER LA COUNTY. HOWEVER...NORTHERLY WINDS WERE OCCURRING OVER THE
MOUNTAINS AND SAN JOAQUIN VALLEY. THIS NORTHERLY FLOW WAS CAUSING
ADDITIONAL CLOUDS TO PILE UP ALONG THE NORTHERN SLOPES OF THE LOCAL
MOUNTAINS THIS MORNING INCLUDING THE I-5 CORRIDOR.
SYNOPTICALLY...A CLOSED 578 DM UPPER LOW CURRENTLY OFF THE CENTRAL
COAST WILL DRIFT SLOWLY SOUTH JUST WEST OF POINT CONCEPTION BY THIS
AFTERNOON. THE PROXIMITY OF THE UPPER LOW WILL ALLOW FAVORABLE COOL
CYCLONIC FLOW OVER MOST OF LOS ANGELES...VENTURA AND SANTA BARBARA
COUNTIES TODAY. THERE IS NOT MUCH IN THE WAY OF MOISTURE ASSOCIATED
WITH THE UPPER LOW...BUT THERE WILL BE PLENTY LOW CLOUDS LINGERING
ACROSS THE COAST AND VALLEYS THROUGH THIS MORNING AND INTO THE
AFTERNOON ACROSS MOST COASTAL AREAS. RAP AND NAM-WRF MODELS
INDICATED THAT THERE WOULD BE ENOUGH INSTABILITY AND LIMITED MID
LEVEL MOISTURE TO WARRANT A SLIGHT CHANCE FOR SHOWERS OR
THUNDERSTORMS TO DEVELOP OVER THE VENTURA COUNTY MOUNTAINS AS WELL
AS PORTIONS OF THE SANTA BARBARA COUNTY MOUNTAINS THIS AFTERNOON AND
EVENING HOURS. TEMPERATURES WILL CONTINUE TO TREND COOLER THROUGH
SATURDAY AS THE UPPER LOW MOVES DIRECTLY OVER SBA/VENTURA
COUNTIES SATURDAY AFTERNOON. THERE IS NOT MUCH DIFFLUENCE ASSOCIATED
WITH THE UPPER LOW FOR SATURDAY AND MODELS WERE NOT PICKING UP ON
ANY ADDITIONAL MOISTURE OR CONVECTIVE PARAMETERS ACROSS THE LOCAL
MOUNTAINS. WILL LET LATER SHIFTS LOOK CLOSER TO SEE IF SLIGHT CHANCE
POPS WILL BE NEEDED FOR SAT IN THE LOCAL MTNS ONCE AGAIN.EXPECT HIGH
TEMPS TO BE NEAR OR JUST BELOW NORMAL TODAY AND SATURDAY.
BY SUNDAY...THE UPPER LOW WILL FILL IN AND MOVE NE INTO NEVADA
ALLOWING HEIGHTS AND THICKNESS LVLS TO RISE. THERE WILL BE NIGHT
THROUGH MORNING LOW CLOUDS BUT A QUICKER BURNOFF AND HIGH TEMPS WILL
BE A FEW DEGREES HIGHER...ESPECIALLY ACROSS INTERIOR
LOCATIONS...WITH WARMEST VALLEY LOCATIONS IN THE MID 80S...AND MID
TO UPPER 70S ALONG THE COAST.
.LONG TERM (MON-THU)...BOTH GFS AND ECMWF STAY IN PRETTY GOOD
AGREEMENT OVER THE LONG TERM PERIOD. A WEAK RIDGE WILL BEGIN TO
BUILD OVER BAJA CALIFORNIA WHILE MUCH OF NORTHERN CALIFORNIA REMAIN
UNDER A BROAD UPPER TROUGH THROUGH WED. EXPECT NIGHT THROUGH MORNING
LOW CLOUDS FOR COASTAL AREAS AND POSSIBLY SOME COASTAL VALLEYS
THROUGH WED MORNING. TEMPS WILL CONTINUE TO REBOUND MONDAY AND
TUESDAY WITH HIGHS REACHING THE LOWER 90S ACROSS WARMEST VALLEY
LOCATIONS. FOR WED AND THU...A BROAD UPPER TROUGH WILL BEGIN TO DIG
FARTHER SOUTH. THE GFS IS SHOWING A SHARPER TROUGH WHICH WOULD MEAN
MORE SIGNIFICANT COOLING BY THURSDAY...WHERE THE EUROPEAN MODEL IS
LESS PRONOUNCED. AT THIS POINT HAVE TRENDED HIGH TEMPS DOWN SLIGHTLY
FOR WED...WITH A FEW MORE DEGREES OF COOLING FOR THURSDAY TO
SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...19/1145Z.
DEEP MARINE LAYER IN PLACE WITH VERY WEAK INVERSION. WIDESPREAD MVFR
CIGS WILL LIKELY SCATTER OUT LATE THIS MORNING OR EARLY THIS
AFTERNOON...BUT THERE IS A CHANCE THAT CIGS WILL LINGER. EXPECT
WDSPRD STRATUS WITH MOSTLY MVFR CONDS AGAIN TONIGHT/SAT MORNING.
KLAX...MODERATE CONFIDENCE IN 12Z TAF. THERE IS A 30 PERCENT CHANCE
THAT CIGS WILL LINGER THRU THE DAY.
KBUR...MODERATE TO HIGH CONFIDENCE IN 12Z TAF. THERE IS A 20 PERCENT
CHANCE THAT CIGS WILL LINGER THRU THE DAY.
&&
.MARINE...19/900 AM.
THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS IN THE VICINITY OF
THE NORTHERN CHANNEL ISLANDS WILL DEVELOP THIS AFTERNOON AND END
LATE TONIGHT. THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL
REDEVELOP EACH EVENING AND EXIST SEVERAL HOURS EACH DAY
SUNDAY THROUGH TUESDAY. THERE IS A CHANCE THE NORTHWEST WINDS WILL
INCREASE TO GALES THURSDAY AFTERNOON IN THE VICINITY OF THE NORTHERN
ISLANDS TO SAN NICOLAS ISLAND. A MIXED WEST NORTHWEST SWELL AND
SOUTH SOUTHWEST SWELL WILL CONTINUE TO SUBSIDE AND LINGER THROUGH
SATURDAY. SWELLS ORIGINATING FROM A FAST MOVING AND SHORT LIVED GULF
OF ALASKA STORM ON THURSDAY ARE EXPECTED TO ARRIVE SUNDAY FROM
295-305. THERE IS A CHANCE THE SWELL WILL PEAK SUNDAY NIGHT AND
LINGER THROUGH TUESDAY. A LOW PRESSURE SYSTEM IS LIKELY TO DEVELOP
OVER THE EASTERN PACIFIC NEXT WEEK MONDAY THROUGH TUESDAY AND
GUIDANCE HAD TRENDED DEEPER WITH THE SYSTEM. SWELLS GENERATED BY
STORM FORCE WINDS ARE EXPECTED TO ARRIVE FROM 300-310 DEGREES
WEDNESDAY EVENING AND PEAK THURSDAY AND LINGER THROUGH FRIDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...JACKSON/KAPLAN
AVIATION/MARINE...DB/30
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
240 PM EDT FRI SEP 19 2014
...UNSETTLED WET PATTERN WITH COOLER TEMPS THROUGH SAT...
.SHORT TERM...THIS AFTN THROUGH TONIGHT...
RADAR LOOP DEPICTED THE DYNAMIC WEATHER PATTERN WELL WITH LOW LEVEL
ONSHORE FLOW PUSHING SFC BASED CONVECTION FROM THE ATLANTIC
WESTWARD...WHILE A STREAM OF MID LEVEL MOISTURE FROM THE WEST WAS
BRINGING LIGHT TO MODERATE STRATIFORM RAINFALL FROM GNV TO PALM
COAST SOUTHWARD. UPPER LEVEL DIVERGENCE WAS INCREASING AS AN UPPER
TROUGH CONTINUE TO DIG OVER THE CENTRAL GULF COAST STATES...WHILE
SHALLOW ENE LOW LEVEL FLOW WAS BRINGING LOW LEVEL ISENTROPIC LIFT
OVER OUR SOUTHERN FL ZONES. SHALLOW AND MID LEVEL MOISTURE WAS
GRADUALLY INCREASING FROM THE ESE AS LOW PRESSURE DEEPENED OVER THE
EASTERN GULF.
UPDATED THE FORECAST TO REFLECT LATEST HRRR MODEL GUIDANCE WHICH
INDICATED ADDITIONAL CONVECTIVE DEVELOPMENT GENERALLY FROM
GAINESVILLE NORTHWARD WITH ISOLATED TSTORMS POSSIBLY BECOMING STRONG
DUE TO INCREASING SHEAR AHEAD OF STRONG DEEPENING UPPER TROUGH OVER
THE GULF COAST REGION. STRONG STORMS WOULD BE CAPABLE OF GUSTY
WINDS...FREQUENT LIGHTNING AND EVEN HAIL. FARTHER SOUTH...A LIGHT TO
MODERATE STRATIFORM RAINFALL WILL CONTINUE WITH EMBEDDED TSTORMS
POSSIBLE.
THIS EVENING PRECIP WILL GRADUALLY DECREASE FROM NW TO SE AS THE
UPPER LEVEL TROUGH DIGS FURTHER AND INDUCES SFC LOW PRESSURE TO
DEEPEN OVER S FL AND THEN OFFSHORE OF THE SE FL ATLANTIC COAST. THIS
WILL OCCUR AS A SFC RIDGE AXIS BEGINS TO NUDGED FARTHER SOUTHWARD
DOWN THE LEE OF THE APPALACHIANS AND OVER N GA. THIS SCENARIO WILL
INCREASE ENE FLOW AND COASTAL CONVERGENCE ALONG OUR LOCAL
COASTLINE...ESPECIALLY AFTER MIDNIGHT...WHICH COULD BRING WAVES OF
LOCALLY HEAVY RAINFALL TO THE LOCAL COASTLINE EARLY SAT MORNING.
ADVERTISED 60% ALONG THE COAST TONIGHT...FALLING TO LESS THAN 10%
WEST OF TRAIL RIDGE. TEMPS WILL BE MILD IN THE LOW TO MID 70S
COAST...TO UPPER 60S INLAND UNDER MOSTLY CLOUDY SKIES.
SATURDAY THROUGH MONDAY...UPPER TROUGH MOVING OVER THE AREA WILL
DEVELOP A SURFACE LOW OFF THE EAST CENTRAL FL COAST EARLY SATURDAY.
UPPER DIVERGENCE AND ISENTROPIC LIFT WILL CONTINUE THE RAIN ACROSS
MOST OF THE AREA ON SATURDAY. RAIN WILL TAPER OFF SATURDAY NIGHT AS
UPPER TROUGH AND SURFACE LOW LIFT NE TO THE CAROLINA COAST. DRIER
AIR WILL ADVECT INTO SE GA SUNDAY WITH MOIST AXIS AND CHANCE OF
SHOWERS PERSISTING OVER NE FL. ON MONDAY A COLD FRONT WILL DROP
SOUTH INTO S GA BRINGING A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS/THUNDERSTORMS TO THE AREA.
.LONG TERM...TUESDAY THROUGH FRIDAY...MODERATE ONSHORE WINDS ARE
EXPECTED FOR MUCH OF NEXT WEEK. SURFACE HIGH PRESSURE TO THE NORTH
WILL BE REINFORCED ON WEDNESDAY AS A 1035 MB HIGH DROPS SE FROM
CANADA INTO NEW ENGLAND. WEAK CYCLONIC FLOW ALOFT ASSOCIATED WITH
UPPER TROUGHING COMBINED WITH DEEP MOISTURE WILL CONTINUE RAIN
CHANCES THROUGH THE PERIOD. POPS WILL BE ABOVE NORMAL WITH
TEMPERATURES NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
RAIN ALONG A DEVELOPING FRONTAL BOUNDARY WILL CONTINUE TO IMPACT GNV
THROUGH THE NIGHT. TERMINALS NORTH OF THE BOUNDARY WILL SEE IMPACTS
FROM SCATTERED SHOWERS AND THUNDERSTORMS BETWEEN 18Z AND 00Z. EXPECT
BRIEF BOUTS OF GUSTY WINDS AND IFR/MVFR VIS AND CEILINGS. SOME LOW
CEILINGS MAY BE POSSIBLE HEADING INTO TOMORROW MORNING BUT WE WILL
WAIT TO ADDRESS THOSE IN THE NEXT PACKAGE WHEN THERE IS MORE
CONFIDENCE.
&&
.MARINE...EAST WINDS 10-15 KTS PREVAILED THIS AFTN WITH SEAS 3 FT OR
LESS. AS LOW PRESSURE DEEPENS OVER S FL AND JUST OFFSHORE OF THE FL
ATLANTIC COAST TONIGHT...ENE FLOW WILL INCREASE OVER THE GA WATERS.
THERE WAS STILL MODEL DISCREPANCY WITH THE STRENGTH OF THE LOW AND
RESULTANT NE SURGE DOWN THE LOCAL COASTLINE...WITH THE NAM12 MUCH
STRONGER COMPARED TO THE GFS. THUS USED A MODEL BLEND WHICH YIELDED
PREVAILING SPEEDS INCREASING TO 15-20 KTS LATE TONIGHT INTO SAT N OF
ST AUGUSTINE. PLAN TO RAISE A SMALL CRAFT EXERCISE CAUTION FOR THE
WATERS N OF ST AUGUSTINE DIVISION FOR WINDS 15-20 KTS. IF NAM12 PANS
OUT AND THE LOW DEEPENS FURTHER...A LAST MINUTE ADVISORY MAY BE
NEEDED FOR OFFSHORE WINDS FOR WINDS 20-25 KTS. SEAS WILL BUILD FROM
2-4 FT TONIGHT TO 4-6 FT OFFSHORE LEGS LATE SAT INTO SAT NIGHT.
ONSHORE FLOW WILL CONTINUE INTO SUN WHILE WEAKENING AS THE SFC LOW
EJECTS NE OF THE LOCAL WATERS AND HIGH PRESSURE BUILDS IN FROM THE
WEST. WINDS AND SEAS WILL SUBSIDE INTO EARLY NEXT WEEK.
.RIP CURRENTS...ONSHORE FLOW WILL CONTINUE AN ELEVATED RISK OF RIP
CURRENTS TODAY AND SATURDAY WITH A MODERATE RISK EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 69 83 66 86 / 20 50 40 10
SSI 73 80 71 82 / 60 70 70 30
JAX 70 82 68 84 / 50 70 60 20
SGJ 73 81 71 81 / 60 70 60 40
GNV 67 83 66 85 / 40 50 50 40
OCF 68 83 67 86 / 70 40 40 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
ENYEDI/ZIBURA/WALSH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
248 PM EDT FRI SEP 19 2014
.SYNOPSIS...
AN UPPER TROUGH AND SURFACE BOUNDARY WILL SLOWLY MOVE THROUGH THE
REGION TODAY AND TONIGHT...AND PUSH TOWARDS THE COAST SATURDAY.
DRIER AIR WILL ENTER THE REGION SUNDAY. A DRY FRONT WILL MOVE
THROUGH LATE SUNDAY NIGHT AND EARLY MONDAY. DRY HIGH PRESSURE WILL
BE IN CONTROL EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPPER TROUGH ALONG THE EAST COAST. EMBEDDED DISTURBANCE PROGGED TO
CONTINUE MOVING SLOWLY THROUGH THE REGION TODAY AND TONIGHT AND
BEGIN CUTTING OFF NEAR THE COAST LATE TONIGHT. SURFACE HIGH OVER E
CANADA TO SHIFT EAST INTO NEW ENGLAND AND OFFSHORE WATERS ALLOWING
SOME RIDGING TO BUILD DOWN THE EAST COAST. MEANWHILE SURFACE WAVE
OFFSHORE TO DEVELOP SOME IN RESPONSE TO UPPER ENERGY. THIS WILL
PROVIDE AN INCREASING LOW LEVEL E TO NE FLOW OFF THE ATLANTIC.
SEVERAL SURFACE BOUNDARIES APPEAR TO BE IN PLAY. THE ONE THAT
PUSHED THROUGH OUR FORECAST AREA (FA) THIS MORNING APPEARS TO BE
SOUTH AND WEST OF OUR FA NOW. ANOTHER BOUNDARY/DEWPOINT GRADIENT
IS NEAR THE NE FA...BEHIND WHICH DRIER AIR NOTED OVER CENT/E NC
AND NE SC. IT APPEARS DRIER AIR WILL ENTER THE NE FA TODAY AND
PRECLUDE SHOWER ACTIVITY THERE. DISSIPATING CLOUDINESS ALLOWING
BETTER DIURNAL HEATING TO BEGIN...WHICH IS EXPECTED TO RESULT IN
SHOWER AND POSSIBLE THUNDERSTORM ACTIVITY THIS AFTERNOON AND
EVENING...FOCUSED MAINLY ALONG ANY BOUNDARIES. LATEST HIGH RES
MODELS FOCUS MOST ACTIVITY GENERALLY NEAR THE SOUTHERN AND WESTERN
FA. LATEST RADAR INDICATING ACTIVITY DEVELOPING ACROSS THAT AREA
AND NEAR THE COAST WHICH IS DRIFTING NW. TONIGHT...A CONTINUED AND
INCREASING LOW LEVEL MOISTURE FLUX OFF THE ATLANTIC...WITH AN EAST
FLOW AROUND 20 TO 25 KNOTS PROGGED AT 925MB TO 850MB...TO PROVIDE
POSSIBILITY OF SHOWER ACTIVITY PENETRATING INLAND INTO OUR
SOUTHERN FA...ALONG WITH POSSIBILITY OF INCREASING LOW LEVEL CLOUD
COVER. MOST MODEL OUTPUT FOCUSING MOST CONVECTIVE ACTIVITY NEAR
THE COASTAL PLAIN...BUT LATEST RAP MODEL SUGGESTING ACTIVITY COULD
CONTINUE TO STREAM INTO THE S MIDLANDS AND CSRA. SOME UNCERTAINTY
BUT WILL MAINTAIN SLIGHT CHANCE TO CHANCE POPS MAINLY S FA/CSRA
TONIGHT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
SATURDAY...A CLOSED UPPER LEVEL LOW OFF THE SOUTHEAST COAST WILL
SLOWLY MOVE NORTHEAST. SURFACE HIGH PRESSURE WILL CONTINUE TO WEDGE
INTO THE WESTERN CAROLINAS FROM THE NORTH. SURFACE LOW PRESSURE
OFF THE NORTH FLORIDA COAST WILL MOVE NORTHEAST TO A POSITION OFF
THE NC COAST SATURDAY NIGHT. MOIST EASTERLY FLOW AROUND THE
SURFACE LOW WILL HOLD MOST THE THE PRECIPITATION EAST OF THE
MIDLANDS. PWAT GREATER THAN OR EQUAL TO 1.50 INCHES IS FORECAST
ALONG AND EAST OF A LINE FROM SUMTER THROUGH COLUMBIA TO AUGUSTA.
THUS WILL CONTINUE SLIGHT CHANCE POPS FOR THE CENTRAL MIDLANDS AND
CSRA WITH CHANCE POPS ACROSS THE EXTREME EASTERN MIDLANDS AS
SHOWERS ROTATE AROUND THE LOW. BOTH THE SURFACE UPPER LOW WILL
LIFT NORTHEAST AWAY FROM THE FORECAST AREA ALLOWING DRIER AIR TO
FILTER IN FROM THE WEST SATURDAY NIGHT. DRY FORECAST SATURDAY NIGHT.
EXPECT NORTHEASTERLY WINDS AROUND 10 KNOTS WITH GUSTS AROUND 15
KNOTS SATURDAY. HIGHS WILL BE IN THE LOWER 80S WITH LOWS IN THE
LOWER 60S AS SKIES CLEAR.
SUNDAY...THE CLOSED LOW OFF THE COAST WILL CONTINUE TO TRACK
NORTHEASTWARD TAKING THE BETTER MOISTURE WITH IT. H850 FLOW
BECOMES DOWNSLOPE AND PWAT DECREASES TO BELOW AN INCH WITH WEAK
INSTABILITY. HAVE CONTINUED TO INDICATE A DRY FORECAST. SUNNY
SKIES AND DOWNSLOPE WINDS SHOULD ALLOW TEMPERATURES TO WARM INTO
THE MID 80S TO AROUND 90 DEGREES. NEXT LOW PRESSURE SYSTEM OVER
THE NORTHERN GREAT LAKES REGION WILL DRAG A COLD FRONT ACROSS THE
OHIO AND TENNESSEE VALLEYS ON SUNDAY. THIS FRONT WILL MOVE INTO
THE UPSTATE LATE SUNDAY NIGHT. WENT WITH CONSENSUS FOR LOWS IN THE
LOW TO MID 60S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AN UPPER TROUGH OVER THE GREAT LAKES REGION WILL SHIFT EAST ON
MONDAY PUSHING A COLD FRONT THROUGH THE FORECAST AREA. THE GFS IS
QUICKER WITH THE TIMING OF THE FRONT THAN THE NAM. THE TIMING OF
THE FRONT WILL INFLUENCE HEATING AND THE AMOUNT OF INSTABILITY.
CONTINUED TO INDICATE ONLY A SLIGHT CHANCE AS MOISTURE APPEARS
LIMITED AND TIMING APPEARS TOO EARLY TO BE DIURNALLY FAVORABLE.
MUCH DRIER AND COOLER AIR SHOULD REACH THE AREA LATE MONDAY IN THE
WAKE OF THE FRONT...JUST IN TIME FOR THE FALL EQUINOX. TUESDAY
MORNING LOW TEMPERATURES ARE FORECAST IN THE UPPER 50S NORTH TO
LOWER 60S SOUTH. THE FRONT WILL BE WELL OFFSHORE BY TUESDAY WITH
HIGH PRESSURE BUILDING IN FROM THE OHIO VALLEY. THE UPPER TROUGH
WILL BE OFFSHORE BY WEDNESDAY WITH AN UPPER RIDGE BUILDING OVER
THE GREAT LAKES REGION. HIGH OVER NEW ENGLAND WEDNESDAY THROUGH
FRIDAY WILL CREATE A STRONG EASTERLY LOW LEVEL FLOW OFF THE
ATLANTIC. HAVE FORECAST MOSTLY CLOUDY SKIES ALONG WITH A CHANCE OF
SHOWERS AND BELOW NORMAL TEMPERATURES FOR THE END OF THE WEEK.
HIGHS WILL BE IN THE 70S WITH LOWS IN THE UPPER 50S TO LOWER 60S.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS CURRENTLY. DIURNAL HEATING EXPECTED TO PROMOTE
CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORMS THIS AFTERNOON AND
EVENING. AT THIS TIME...WILL HANDLE WITH VCSH IN THE TAFS AND
UPGRADE LATER BASED ON RADAR TRENDS IF/WHEN CONFIDENCE WARRANTS.
LATER TONIGHT...CONVECTION MAY CONTINUE TO AFFECT MAINLY SOUTHERN
AND WESTERN AREAS...OGB/AGS/DNL...DUE TO LOCATION OF BEST LOW
LEVEL MOISTURE FLUX OFF THE ATLANTIC. ALSO...THIS ALONG WITH
DIURNAL COOLING EXPECTED TO RESULT IN LOW CLOUD DEVELOPMENT LATE
TONIGHT INTO EARLY SATURDAY MORNING...WITH MVFR TO IFR CIGS
POSSIBLE. EXPECT A RETURN TO VFR BY LATE SATURDAY MORNING OR
MIDDAY. CONVECTIVE ACTIVITY SATURDAY EXPECTED TO FAVOR AREAS NEAR
THE COAST AND WILL NOT INCLUDE MENTION IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING FOG/STRATUS
POSSIBLE THROUGH EARLY SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
245 PM EDT FRI SEP 19 2014
.SYNOPSIS...
AN UPPER TROUGH AND SURFACE BOUNDARY WILL SLOWLY MOVE THROUGH THE
REGION TODAY AND TONIGHT...AND PUSH TOWARDS THE COAST SATURDAY.
DRIER AIR WILL ENTER THE REGION SUNDAY. A DRY FRONT WILL MOVE
THROUGH LATE SUNDAY NIGHT AND EARLY MONDAY. DRY HIGH PRESSURE WILL
BE IN CONTROL EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER TROUGH ALONG THE EAST COAST. EMBEDDED DISTURBANCE PROGGED TO
CONTINUE MOVING SLOWLY THROUGH THE REGION TODAY AND TONIGHT AND
BEGIN CUTTING OFF NEAR THE COAST LATE TONIGHT. SURFACE HIGH OVER E
CANADA TO SHIFT EAST INTO NEW ENGLAND AND OFFSHORE WATERS ALLOWING
SOME RIDGING TO BUILD DOWN THE EAST COAST. MEANWHILE SURFACE WAVE
OFFSHORE TO DEVELOP SOME IN RESPONSE TO UPPER ENERGY. THIS WILL
PROVIDE AN INCREASING LOW LEVEL E TO NE FLOW OFF THE ATLANTIC.
SEVERAL SURFACE BOUNDARIES APPEAR TO BE IN PLAY. THE ONE THAT
PUSHED THROUGH OUR FORECAST AREA (FA) THIS MORNING APPEARS TO BE
SOUTH AND WEST OF OUR FA NOW. ANOTHER BOUNDARY/DEWPOINT GRADIENT
IS NEAR THE NE FA...BEHIND WHICH DRIER AIR NOTED OVER CENT/E NC
AND NE SC. IT APPEARS DRIER AIR WILL ENTER THE NE FA TODAY AND
PRECLUDE SHOWER ACTIVITY THERE. DISSIPATING CLOUDINESS ALLOWING
BETTER DIURNAL HEATING TO BEGIN...WHICH IS EXPECTED TO RESULT IN
SHOWER AND POSSIBLE THUNDERSTORM ACTIVITY THIS AFTERNOON AND
EVENING...FOCUSED MAINLY ALONG ANY BOUNDARIES. LATEST HIGH RES
MODELS FOCUS MOST ACTIVITY GENERALLY NEAR THE SOUTHERN AND WESTERN
FA. LATEST RADAR INDICATING ACTIVITY DEVELOPING ACROSS THAT AREA
AND NEAR THE COAST WHICH IS DRIFTING NW. TONIGHT...A CONTINUED AND
INCREASING LOW LEVEL MOISTURE FLUX OFF THE ATLANTIC...WITH AN EAST
FLOW AROUND 20 TO 25 KNOTS PROGGED AT 925MB TO 850MB...TO PROVIDE
POSSIBILITY OF SHOWER ACTIVITY PENETRATING INLAND INTO OUR
SOUTHERN FA...ALONG WITH POSSIBILITY OF INCREASING LOW LEVEL CLOUD
COVER. MOST MODEL OUTPUT FOCUSING MOST CONVECTIVE ACTIVITY NEAR
THE COASTAL PLAIN...BUT LATEST RAP MODEL SUGGESTING ACTIVITY COULD
CONTINUE TO STREAM INTO THE S MIDLANDS AND CSRA. SOME UNCERTAINTY
BUT WILL MAINTAIN SLIGHT CHANCE TO CHANCE POPS MAINLY S FA/CSRA
TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
SATURDAY...A CLOSED UPPER LEVEL LOW OFF THE SOUTHEAST COAST WILL
SLOWLY MOVE NORTHEAST. SURFACE HIGH PRESSURE WILL CONTINUE TO WEDGE
INTO THE WESTERN CAROLINAS FROM THE NORTH. SURFACE LOW PRESSURE
OFF THE NORTH FLORIDA COAST WILL MOVE NORTHEAST TO A POSITION OFF
THE NC COAST SATURDAY NIGHT. MOIST EASTERLY FLOW AROUND THE
SURFACE LOW WILL HOLD MOST THE THE PRECIPITATION EAST OF THE
MIDLANDS. PWAT GREATER THAN OR EQUAL TO 1.50 INCHES IS FORECAST TO
TO ALONG AND EAST OF A LINE FROM SUMTER THROUGH COLUMBIA TO
AUGUSTA. THUS WILL CONTINUE SLIGHT CHANCE POPS FOR THE CENTRAL
MIDLANDS AND CSRA WITH CHANCE POPS ACROSS THE EXTREME EASTERN
MIDLANDS AS SHOWERS ROTATE AROUND THE LOW. BOTH THE SURFACE UPPER
LOW WILL LIFT NORTHEAST AWAY FROM THE FORECAST AREA ALLOWING DRIER
AIR TO FILTER IN FROM THE WEST. DRY FORECAST SATURDAY NIGHT.
EXPECT NORTHEASTERLY WINDS AROUND 10 KNOTS WITH GUSTS AROUND 15
KNOTS SATURDAY. HIGHS WILL BE IN THE LOWER 80S WITH LOWS IN THE
LOWER 60S AS SKIES CLEAR.
SUNDAY...THE CLOSED LOW OFF THE COAST WILL CONTINUE TO TRACK
NORTHEASTWARD TAKING THE BETTER MOISTURE WITH IT. H850 FLOW
BECOMES DOWNSLOPE AND PWAT DECREASES TO BELOW AN INCH WITH WEAK
INSTABILITY. HAVE CONTINUED TO INDICATE A DRY FORECAST. SUNNY
SKIES AND DOWNSLOPE WINDS SHOULD ALLOW TEMPERATURES TO WARM INTO
THE MID 80S TO AROUND 90 DEGREES. NEXT LOW PRESSURE SYSTEM OVER
THE NORTHERN GREAT LAKES REGION WILL DRAG A COLD FRONT ACROSS THE
OHIO AND TENNESSEE VALLEYS ON SUNDAY. THIS FRONT WILL MOVE INTO
THE UPSTATE LATE SUNDAY NIGHT. WENT WITH CONSENSUS FOR LOWS IN THE
LOW TO MID 60S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AN UPPER TROUGH OVER THE GREAT LAKES REGION WILL SHIFT EAST ON
MONDAY PUSHING A COLD FRONT THROUGH THE FORECAST AREA. THE GFS IS
QUICKER WITH THE TIMING OF THE FRONT THAN THE NAM. THE TIMING OF
THE FRONT WILL INFLUENCE HEATING AND THE AMOUNT OF INSTABILITY.
CONTINUED TO INDICATE ONLY A SLIGHT CHANCE AS MOISTURE APPEARS
LIMITED AND TIMING APPEARS TOO EARLY TO BE DIURNALLY FAVORABLE.
MUCH DRIER AND COOLER AIR SHOULD REACH THE AREA LATE MONDAY IN THE
WAKE OF THE FRONT...JUST IN TIME FOR THE FALL EQUINOX. TUESDAY
MORNING LOW TEMPERATURES ARE FORECAST IN THE UPPER 50S NORTH TO
LOWER 60S SOUTH. THE FRONT WILL BE WELL OFFSHORE BY TUESDAY WITH
HIGH PRESSURE BUILDING IN FROM THE OHIO VALLEY. THE UPPER TROUGH
WILL BE OFFSHORE BY WEDNESDAY WITH AN UPPER RIDGE BUILDING OVER
THE GREAT LAKES REGION. HIGH OVER NEW ENGLAND WEDNESDAY THROUGH
FRIDAY WILL CREATE A STRONG EASTERLY LOW LEVEL FLOW OFF THE
ATLANTIC. HAVE FORECAST MOSTLY CLOUDY SKIES ALONG WITH A CHANCE OF
SHOWERS AND BELOW NORMAL TEMPERATURES FOR THE END OF THE WEEK.
HIGHS WILL BE IN THE 70S WITH LOWS IN THE UPPER 50S TO LOWER 60S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS CURRENTLY. DIURNAL HEATING EXPECTED TO PROMOTE
CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORMS THIS AFTERNOON AND
EVENING. AT THIS TIME...WILL HANDLE WITH VCSH IN THE TAFS AND
UPGRADE LATER BASED ON RADAR TRENDS IF/WHEN CONFIDENCE WARRANTS.
LATER TONIGHT...CONVECTION MAY CONTINUE TO AFFECT MAINLY SOUTHERN
AND WESTERN AREAS...OGB/AGS/DNL...DUE TO LOCATION OF BEST LOW
LEVEL MOISTURE FLUX OFF THE ATLANTIC. ALSO...THIS ALONG WITH
DIURNAL COOLING EXPECTED TO RESULT IN LOW CLOUD DEVELOPMENT LATE
TONIGHT INTO EARLY SATURDAY MORNING...WITH MVFR TO IFR CIGS
POSSIBLE. EXPECT A RETURN TO VFR BY LATE SATURDAY MORNING OR
MIDDAY. CONVECTIVE ACTIVITY SATURDAY EXPECTED TO FAVOR AREAS NEAR
THE COAST AND WILL NOT INCLUDE MENTION IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING FOG/STRATUS
POSSIBLE THROUGH EARLY SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
129 PM EDT FRI SEP 19 2014
.SYNOPSIS...
AN UPPER TROUGH AND SURFACE BOUNDARY WILL SLOWLY MOVE THROUGH THE
REGION TODAY AND TONIGHT...AND PUSH TOWARDS THE COAST SATURDAY.
DRIER AIR WILL ENTER THE REGION SUNDAY. A DRY FRONT WILL MOVE
THROUGH LATE SUNDAY NIGHT AND EARLY MONDAY. DRY HIGH PRESSURE WILL
BE IN CONTROL EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER TROUGH ALONG THE EAST COAST. EMBEDDED DISTURBANCE PROGGED TO
CONTINUE MOVING SLOWLY THROUGH THE REGION TODAY AND TONIGHT AND
BEGIN CUTTING OFF NEAR THE COAST LATE TONIGHT. SURFACE HIGH OVER E
CANADA TO SHIFT EAST INTO NEW ENGLAND AND OFFSHORE WATERS ALLOWING
SOME RIDGING TO BUILD DOWN THE EAST COAST. MEANWHILE SURFACE WAVE
OFFSHORE TO DEVELOP SOME IN RESPONSE TO UPPER ENERGY. THIS WILL
PROVIDE AN INCREASING LOW LEVEL E TO NE FLOW OFF THE ATLANTIC.
SEVERAL SURFACE BOUNDARIES APPEAR TO BE IN PLAY. THE ONE THAT
PUSHED THROUGH OUR FORECAST AREA (FA) THIS MORNING APPEARS TO BE
SOUTH AND WEST OF OUR FA NOW. ANOTHER BOUNDARY/DEWPOINT GRADIENT
IS NEAR THE NE FA...BEHIND WHICH DRIER AIR NOTED OVER CENT/E NC
AND NE SC. IT APPEARS DRIER AIR WILL ENTER THE NE FA TODAY AND
PRECLUDE SHOWER ACTIVITY THERE. DISSIPATING CLOUDINESS ALLOWING
BETTER DIURNAL HEATING TO BEGIN...WHICH IS EXPECTED TO RESULT IN
SHOWER AND POSSIBLE THUNDERSTORM ACTIVITY THIS AFTERNOON AND
EVENING...FOCUSED MAINLY ALONG ANY BOUNDARIES. LATEST HIGH RES
MODELS FOCUS MOST ACTIVITY GENERALLY NEAR THE SOUTHERN AND WESTERN
FA. LATEST RADAR INDICATING ACTIVITY DEVELOPING ACROSS THAT AREA
AND NEAR THE COAST WHICH IS DRIFTING NW. TONIGHT...A CONTINUED AND
INCREASING LOW LEVEL MOISTURE FLUX OFF THE ATLANTIC...WITH AN EAST
FLOW AROUND 20 TO 25 KNOTS PROGGED AT 925MB TO 850MB...TO PROVIDE
POSSIBILITY OF SHOWER ACTIVITY PENETRATING INLAND INTO OUR
SOUTHERN FA...ALONG WITH POSSIBILITY OF INCREASING LOW LEVEL CLOUD
COVER. MOST MODEL OUTPUT FOCUSING MOST CONVECTIVE ACTIVITY NEAR
THE COASTAL PLAIN...BUT LATEST RAP MODEL SUGGESTING ACTIVITY COULD
CONTINUE TO STREAM INTO THE S MIDLANDS AND CSRA. SOME UNCERTAINTY
BUT WILL MAINTAIN SLIGHT CHANCE TO CHANCE POPS MAINLY S FA/CSRA
TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
SATURDAY...SURFACE HIGH PRESSURE OFF THE NEW ENGLAND COAST WILL
CONTINUE TO PROMOTE NORTHEASTERLY WEDGE FLOW IN THE FORECAST AREA.
A CLOSED LOW OFF THE SOUTHEAST COAST WILL DEEPEN AND MOVE NORTH-
NORTHEASTWARD. THE BEST MOISTURE WILL REMAIN ALONG THE COAST AND
OFFSHORE...CLOSER TO THE CENTER OF THE LOW. KEPT A SLIGHT CHANCE
OF POPS IN THE EASTERN FA. A TIGHTENING PRESSURE GRADIENT WILL
PROMOTE NORTHEASTERLY WINDS AROUND 10 KNOTS WITH GUSTS AROUND 15
KNOTS. HIGHS WILL BE SEVERAL DEGREES BELOW CLIMATOLOGY UNDER THE
WEDGE-LIKE SETUP WITH HIGHS IN THE LOWER 80S.
SUNDAY...THE CLOSED LOW OFF THE COAST WILL CONTINUE TO TRACK
NORTHEASTWARD TAKING THE BETTER MOISTURE WITH IT. H850 FLOW
BECOMES DOWNSLOPE AND PWAT DECREASES TO BELOW AN INCH WITH WEAK
INSTABILITY. HAVE CONTINUED TO INDICATE A DRY FORECAST. RAISED MAX
TEMPERATURES A COUPLE OF DEGREES ON SUNDAY WHICH MODEL THICKNESS
VALUES SUPPORT. NEXT LOW PRESSURE SYSTEM OVER THE NORTHERN GREAT
LAKES REGION WILL DRAG A COLD FRONT ACROSS THE OHIO AND TENNESSEE
VALLEYS ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AN UPPER TROUGH OVER THE GREAT LAKES REGION WILL SHIFT EAST ON
MONDAY PUSHING A COLD FRONT THROUGH THE FORECAST AREA. MOISTURE WILL
INCREASE FROM WEST TO EAST LATE SUNDAY INTO EARLY MONDAY AHEAD OF
THE FRONT WITH MODEL PWAT VALUES MAXIMIZING AROUND 1.5 INCHES 06Z
MONDAY. THE GFS IS QUICKER WITH THE TIMING OF THE FRONT THAN THE
NAM. THE TIMING OF THE FRONT WILL INFLUENCE HEATING AND THE
AMOUNT OF INSTABILITY. CONTINUED TO INDICATE ONLY A SLIGHT CHANCE
AS MOISTURE APPEARS LIMITED AND TIMING APPEARS TOO EARLY TO BE
DIURNALLY FAVORABLE. MUCH DRIER AND COOLER AIR SHOULD REACH THE
AREA LATE MONDAY IN THE WAKE OF THE FRONT...JUST IN TIME FOR THE
FALL EQUINOX. TUESDAY MORNING LOW TEMPERATURES ARE FORECAST IN THE
UPPER 50S NORTH TO LOWER 60S SOUTH. THE FRONT WILL BE WELL
OFFSHORE BY TUESDAY WITH HIGH PRESSURE BUILDING IN FROM THE OHIO
VALLEY. THE UPPER TROUGH WILL BE OFFSHORE BY WEDNESDAY WITH AN
UPPER RIDGE BUILDING OVER THE GREAT LAKES REGION. MAX TEMPERATURES
MAINLY IN THE MIDDLE 70S TO NEAR 80 TUESDAY THROUGH FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS CURRENTLY. DIURNAL HEATING EXPECTED TO PROMOTE
CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORMS THIS AFTERNOON AND
EVENING. AT THIS TIME...WILL HANDLE WITH VCSH IN THE TAFS AND
UPGRADE LATER BASED ON RADAR TRENDS IF/WHEN CONFIDENCE WARRANTS.
LATER TONIGHT...CONVECTION MAY CONTINUE TO AFFECT MAINLY SOUTHERN
AND WESTERN AREAS...OGB/AGS/DNL...DUE TO LOCATION OF BEST LOW
LEVEL MOISTURE FLUX OFF THE ATLANTIC. ALSO...THIS ALONG WITH
DIURNAL COOLING EXPECTED TO RESULT IN LOW CLOUD DEVELOPMENT LATE
TONIGHT INTO EARLY SATURDAY MORNING...WITH MVFR TO IFR CIGS
POSSIBLE. EXPECT A RETURN TO VFR BY LATE SATURDAY MORNING OR
MIDDAY. CONVECTIVE ACTIVITY SATURDAY EXPECTED TO FAVOR AREAS NEAR
THE COAST AND WILL NOT INCLUDE MENTION IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING FOG/STRATUS
POSSIBLE THROUGH EARLY SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
137 PM EDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 137 PM EDT FRI SEP 19 2014
NO UPDATE PLANNED FOR EARLY THIS AFTERNOON AS FORECAST REMAINS ON
TRACK.
UPDATE ISSUED AT 955 AM EDT FRI SEP 19 2014
ALL IS QUIET THIS MORNING WITH A BEAUTIFUL MORNING ONGOING. LAST OF
THE FOG SHOULD BURN OFF OVER THE NEXT HOUR OR SO. NO SIGNIFICANT
CHANGES EXCEPT TO REFINE PRECIPITATION CHANCES BASED ON LATEST HI RES
MODEL GUIDANCE. THIS WAS ONLY TO TRIM SOME AREAS OUT OF THE THREAT
FOR SHOWERS THIS AFTERNOON. OTHERWISE...CURRENT FORECAST SEEMS ON
TRACK.
UPDATE ISSUED AT 740 AM EDT FRI SEP 19 2014
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT SATELLITE IMAGERY AND
OBSERVATIONS. THIS LED TO VERY LITTLE CHANGE...JUST A FRESHENING UP
OF THE HOURLY TEMP AND DEWPOINT CURVES OVER THE NEXT FEW HOURS.
VALLEY FOG ACROSS THE SOUTHERN AND SOUTHEASTERN COUNTIES HAS LIKELY
ALREADY BEGUN TO LIFT AND SHOULD DISSIPATE BY AROUND 9 AM. THE 6Z
GFS AND NAM SUGGESTED THE POTENTIAL FOR A STRAY SHOWER ACROSS THE
SOUTHEASTERN NEAR THE VA OR WV BORDER. THE MODEL CONSENSUS SEEMS TO
INDICATE THE HIGHEST CHANCES FOR AN ISOLATED SHOWER FROM HARLAN
COUNTY NORTHEAST TO PIKE COUNTY AND POSSIBLY INTO THE NEXT TIER OF
COUNTIES TO THE NORTH.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM EDT FRI SEP 19 2014
THROUGH TONIGHT...UPPER LEVEL RIDGING CURRENTLY CENTERED OVER THE
PLAINS STATES WILL BUILD EAST INTO THE LOWER OH VALLEY REGION TODAY
AND INTO TONIGHT. MEANWHILE A WEAK UPPER LOW/TROUGH OF LOW PRESSURE
WILL REMAIN ACROSS THE SOUTHEASTERN CONUS. FURTHER TO THE NORTHWEST A
SERIES OF SHORTWAVES IS EXPECTED TO LEAD TO AN UPPER LEVEL TROUGH
WORKING INTO THE GREAT LAKES REGION BY THE END OF THE PERIOD. AT THE
SFC...HIGH PRESSURE CURRENTLY CENTERED OVER QUEBEC AND EXTENDING
SOUTHWEST INTO THE OH VALLEY REGION WILL MOVE EAST SOUTHEAST TO NEAR
CAPE COD THIS EVENING AND THEN OFF THE NORTHEAST US COAST TONIGHT AND
INTO SATURDAY. AS THE HIGH MOVES EAST...AN INVERTED TROUGH IS
EXPECTED TO DEVELOP ACROSS THE REGION TODAY AND THEN SHIFT WEST AND
WEAKEN TONIGHT. TO THE EAST OF THE CREST OF THE APPALACHIANS...A
RIDGE OF HIGH PRESSURE IS EXPECTED TO EXTEND SOUTHWEST FROM THIS SFC
HIGH INTO THE APPALACHIANS GENERALLY ALONG OR JUST TO THE EAST OF THE
BLUE RIDGE MOUNTAINS LATER TODAY THROUGH EARLY ON SATURDAY. THIS WILL
RESULT IN A RATHER TIGHT PRESSURE GRADIENT...RATHER BRIEFLY THIS
EVENING INTO THE OVERNIGHT HOURS ACROSS THE HIGHER TERRAIN NEAR THE
VA BORDER.
ON SATURDAY THIS RIDGE WILL WEAKEN AS THE UPPER LEVEL TROUGH
APPROACHES THE LOWER OH VALLEY AS THE RIDGE RETREATS WEST AND
BUILDS TOWARD THE NORTHERN ROCKIES. A SFC COLD FRONT WILL ALSO
APPROACH THE LOWER OH VALLEY REGION AT THE END OF THE PERIOD.
ONCE EARLY MORNING VALLEY FOG DISSIPATES...A GENERAL WARMING TREND
IS EXPECTED THROUGH SATURDAY AS THE HIGH DEPARTS TO THE EAST. SOME
MOISTURE SHOULD BE DRAWN WEST AROUND THE DEPARTING HIGH LEADING TO
CU DEVELOPMENT ACROSS THE SOUTHEASTERN PART OF THE CWA FORM MIDDAY
INTO THE AFTERNOON. SOME OF THIS MAY BECOME DEEP ENOUGH FOR A FEW
ISOLATED SHOWERS BELOW THE MID LEVEL CAP. THE NAM IS GENERALLY THE
MOST AGGRESSIVE WITH THIS AMONG THE OPERATIONAL MODELS. THE END OF THE
THE 5Z HRRR RUN GENERALLY KEEPS THE ACTIVITY SOUTH OF THE REGION
THROUGH 20Z.
DIURNAL CU SHOULD DISSIPATE THIS EVENING...BUT MODELS KEEP THE LAYER
NEAR 800 TO 850 MB RATHER MOIST TONIGHT. SOME STRATOCU NEAR THE LEVEL
WILL BE POSSIBLE TONIGHT. PATCHY VALLEY FOG SHOULD STILL
DEVELOP...ESPECIALLY NORTH OF THE VA BORDER COUNTIES. MEANWHILE
DURING THE EVENING WHEN THE PRESSURE GRADIENT IS HIGHEST NEAR THE VA
BORDER AND A PERIOD OF SUSTAINED WINDS OF 10 TO 15 MPH IS
POSSIBLE...ESPECIALLY ACROSS THE EXPOSED RIDGETOPS SUCH AS THE
FLATWOODS AREA OF PIKE COUNTY...PORTIONS OF THE CREST OF PINE
MOUNTAINS AND BLACK MOUNTAINS. MOST LOCATIONS WILL EXPERIENCE LIGHTER
WINDS...WITH VALLEYS FURTHER NORTHWEST LIKELY DECOUPLED. HIGHER
ANTICIPATED DEWPOINTS...A LARGER PRESSURE GRADIENT AND THE POTENTIAL
FOR A FEW CLOUDS SHOULD BRING WARMER MIN T TONIGHT. SOUTH TO
EVENTUALLY SOUTHWEST FLOW WILL BRING WARMER AIR INTO THE REGION ON
SATURDAY. OUTSIDE OF THE HIGH TERRAIN...MAX TEMPS SHOULD REACH THE
LOW TO MID 80S. PRECIPITATION CHANCES ASSOCIATED WITH THE NEXT SYSTEM
SHOULD HOLD OFF UNTIL THE LONG TERM PERIOD.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 307 AM EDT FRI SEP 19 2014
THE EXTENDED PERIOD WILL START OFF ON 0Z SUNDAY WITH A DEEPENING
TROUGH IN THE LONGWAVE PATTERN ACROSS THE DAKOTAS. THIS WILL QUICKLY
MOVE SOUTHEASTWARD ACROSS THE UPPER GREAT LAKES BY SUNDAY
MORNING...QUICKLY PUSHING LOWERING HEIGHTS INTO THE OHIO RIVER
VALLEY THROUGHOUT THE DAY. AT THE SURFACE...A COLD FRONTAL BOUNDARY
WILL PUSH SE TOWARDS KY AS WELL...AND REACH THE OHIO RIVER JUST
AFTER 0Z SUNDAY. MODELS ARE FINALLY COMING INTO A MUCH BETTER
AGREEMENT FOR TIMING OF THE PRECIP ACCOMPANYING THE FRONT...WITH
POPS EXPECTED TO MOVE INTO THE NW PART OF THE CWA AS EARLY AS 12Z
SUNDAY...THEN QUICKLY SPREAD ACROSS THE REMAINING CWA DURING THE
AFTERNOON...BEFORE EXITING SE OF THE REGION BETWEEN 0 AND 6Z MONDAY.
LATEST FORECAST SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL
INSTABILITY FOR THE PRECIP ACCOMPANYING THIS FRONT...THOUGH IT HAS
IMPROVED SLIGHTLY FROM RUN TO RUN OVER THE LAST SEVERAL DAYS. WILL
CONTINUE TO SUPPORT IDEA FOR SOME SCATTERED THUNDERSTORMS DURING THE
DAY SUNDAY...WITH THE BEST CHANCE AROUND AND JUST AFTER 18Z...THEN
DROPPING OFF QUICKLY AS A LOW LEVEL INVERSION SETS UP AFTER 0Z
MONDAY AND WINDS QUICKLY TURN MORE NRLY BEHIND THE FRONTAL PASSAGE.
SOUTHERLY WINDS LEADING UP TO THIS FRONTAL PASSAGE WILL BRING ENOUGH
WAA TO KEEP TEMPS NEAR THE 80 DEGREE MARK FOR DURING THE DAY SUNDAY.
HOWEVER...AS THE FRONT QUICKLY DEPARTS SUNDAY EVENING/NIGHT...KY
WILL FIND ITSELF ON THE BACKSIDE OF THE UPPER LEVEL TROUGHING
PATTERN...WITH STRONG NW FLOW BRINGING MUCH COOLER CANADIAN AIR INTO
THE REGION. AS HIGH PRESSURE TAKES HOLD...DRY AND SUNNY SKIES WILL
PREVAIL. YET HIGH TEMPS ON MONDAY ARE ONLY EXPECTED TO MAKE IT INTO
THE LOW 70S THANKS TO THIS CANADIAN AIR MASS. TUESDAY WILL BE
SIMILAR...AS UPPER LEVEL RIDGING FINALLY MOVES IN OVERHEAD AND
LESSONS THE PRESSURE GRADIENT/STRONGEST NWRLY WINDS. AIRMASS
MODIFICATION WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE
REMAINDER OF THE EXTENDED...HOWEVER WE LIKELY WON/T SEE TEMPS HIT
ABOVE THE 80 DEGREE MARK UNTIL AT LEAST NEXT FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 137 PM EDT FRI SEP 19 2014
MAINLY VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS.
HOWEVER...CLEAR SKIES AND LIGHT WINDS WILL YIELD ANOTHER NIGHT OF
VALLEY FOG. AT THIS TIME...MINIMAL IMPACT IS EXPECTED AT THE TAF
SITES FROM THIS FOG...BUT IF THE FOG ENDS UP BEING A BIT MORE
ROBUST...SOME IMPACTS COULD BE FELT LATE TONIGHT. ANY FOG WILL BURN
OFF BY 9 OR 10 AM SATURDAY MORNING WITH VFR CONDITIONS RETURNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
348 PM EDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT FRI SEP 19 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A LOW AMPLITUDE PATTERN WITH A
MID/UPPER LEVEL RIDGE FROM THE PLAINS TOWARD THE UPPER MS VALLEY AND
A TROUGH FROM SRN SASK INTO THE NRN ROCKIES. AT THE SFC...SRLY FLOW
WAS INCREASING OVER THE UPPER MS VALLEY INTO THE WRN LAKES AS THE
PRES GRADIENT STRENGTHENS BETWEEN A TROUGH FROM MANITOBA INTO THE
NRN PLAINS AND HIGH PRES OVER QUEBEC. INCREASED LOW LEVEL MOISTURE
ADVECTION HAS ALSO BROUGHT SOME LOW CLOUDS INTO MUCH OF CNTRL WI AND
UPPER MI. SOME LIGHT SHOWERS OVER NR CNTRL MN WERE SUPPORTED BY
310K-315K ISENTROPIC ASCENT WITH FAVORABLE 850 MB THETA-E ADVECTION
ON 40-50 KNOT WINDS.
TODAY...RAIN SHOULD CONTINUE TO SPREAD TOWARD UPPER MI AS A WEAK
SHORTWAVE AND THE STRONGER 850 MB THETA-E ADVECTION MOVE IN. WITH
MODEL TRENDS HAVE SLOWING THE ARRIVAL OF THE PCPN INTO UPPER MI AND
THE PRESENCE OF A DRY 850-600 MB LAYER...RAIN CHANCES WILL INCREASE
INTO THE WEST HALF OF THE CWA MAINLY IN THE MID TO LATE AFTERNOON.
ONLY CHANCE FOR TSRA WAS MENTIONED OVER THE FAR WEST WHERE MUCAPE
VALUES CLIMB TO NEAR 800 J/KG. AS THE LOW CLOUDS MIX OUT TOWARD
AFTERNOON AND DAYTIME HEATING INCREASES...A BETTER PORTION OF THE
40-50 KNOT 900-850 MB WINDS MAY MIX TOWARD THE SFC. HOWEVER...THE
DEPTH OF THE MIXED LAYER SHOULD MAINLY ALLOW WIND GUSTS TO NEAR 30
KNOTS. HOWEVER...THERE MAY BE A PERIOD LATE THIS AFTERNOON OVER THE
EAST WHERE THE STRONG WINDS ABOVE THE LAKE MI MARINE LAYER ARE ABLE
TO MIX TOWARD THE SFC OVER THE EAST AND WINDS GUST INTO THE 30-40 MPH
RANGE FOR A TIME...ESPECIALLY FROM NEAR GRAND MARAIS TO NEWBERRY.
TONIGHT...SCT/NMRS SHOWERS AND A FEW THUNDERSTORMS WILL SPREAD
THROUGH THE CWA IN THE EVENING AS THE SFC AND MID LEVEL TROUGH APPROACH
AND THE AXIS OF HIGHER MOISTURE(PWAT TO 1.5 INCHES)/INSTABILITY
(MUCPAE TO NEAR 1K J/KG) MOVE IN. THE POTENTIAL FOR ELEVATED TSRA
REMAINS WITH 850 MB DEWPOINTS TO NEAR 14C.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 348 PM EDT FRI SEP 19 2014
SATURDAY NIGHT AND SUNDAY...A SERIES OF MID-LEVEL SHORTWAVES WILL BE
TRACKING AROUND THE BASE OF A BROADER TROUGH ACROSS ONTARIO AND
HUDSON BAY. A SUBTLE SHORTWAVE AND SFC COLD FRONT WILL BE EXITING
THE EASTERN CWA AT THE BEGINNING OF THE PERIOD WHILE A STRONGER
SHORTWAVE TRACKS SE ACROSS MN. MEANWHILE...AN ASSOCIATED SFC LOW
WILL BE FORMING ON A TRAILING SFC TROUGH FROM THE COLD FRONT
CROSSING THE CWA SATURDAY AFTERNOON. WEAK LOW-LEVEL ISENTROPIC LIFT
AND A NEGATIVE UPPER PV ANOMALY WILL TRACK ACROSS NORTHERN WI AND
MUCH OF UPPER MI SATURDAY NIGHT...THOUGH DEEP MOISTURE WILL HAVE
DECREASED BY THIS TIME BEHIND THE LEAD SHORTWAVE/COLD FRONT.
HOWEVER...OVERALL DYNAMICS WILL BE ENOUGH TO RESULT IN RAIN ACROSS
MUCH OF THE CWA..ESPECIALLY THE SOUTHWEST HALF. THE MID-LEVEL TROUGH
AXIS DOES NOT CLEAR THE CWA UNTIL LATE IN THE DAY SUNDAY...SO
ISOLATED TO SCATTERED SHOWERS COMBINED WITH PLENTY OF CLOUDS SHOULD
CONTINUE UNTIL AT LEAST SUNDAY AFTERNOON.
SUNDAY NIGHT THROUGH MONDAY NIGHT...MID-LEVEL NW FLOW WILL SET-IN
OVER THE REGION THROUGH THIS PERIOD. A SFC RIDGE EXTENDING
NORTHEASTWARD FROM HIGH PRESSURE OVER THE CENTRAL PLAINS WILL CROSS
THE CWA SUNDAY NIGHT. TEMPS ARE A BIT TRICKY TO PIN DOWN AS THERE
ARE INDICATIONS THAT LOW-LEVEL CLOUDS MAY LINGER INTO THE EVENING
ACROSS THE AREA. HOWEVER...CLEARING SHOULD OCCUR OVERNIGHT. WENT
WITH THE LOWER END OF TEMP GUIDANCE IN THE MID 30S FOR INTERIOR
LOCATIONS.
A WEAK SHORTWAVE WILL TRACK SOUTHEASTWARD OUT OF FAR NORTHERN
CANADA...PASSING BETWEEN LAKE SUPERIOR AND JAMES BAY MONDAY
AFTERNOON AND EVENING. AN ASSOCIATED SFC TROUGH WILL THEN CROSS
UPPER MI MONDAY NIGHT. MID-LEVEL MOISTURE IS LACKING...AND WITH THE
RIGHT ENTRANCE OF THE UPPER JET OVERHEAD AND MID-LEVEL Q-VECTOR CONV
TIED DIRECTLY TO THE TROUGH...AM EXPECTING A DRY FRONTAL PASSAGE
WITH ONLY SOME SCATTERED CLOUDS.
TUESDAY THROUGH FRIDAY...A GRADUAL WARMING TREND WILL COMMENCE AS
ANOTHER SFC HIGH PRESSURE TRACKS SOUTHEASTWARD ACROSS NORTHERN
ONTARIO TUESDAY WHILE A MID-LEVEL RIDGE BUILDS OVER THE UPPER MS
VALLEY. THIS WILL BRING DRY WEATHER THROUGH MUCH OF WEDNESDAY. AS
THE RIDGE AXIS MOVES OVER THE UPPER GREAT LAKES WEDNESDAY NIGHT INTO
THURSDAY...A SHORTWAVE TROUGH MOVING ALONG THE INTERNATIONAL BORDER
WILL CROSS NORTH OF UPPER MI THURSDAY. THERE IS SOME MODEL
DISAGREEMENT ON THE STRENGTH OF THE TROUGH...AND THUS HOW EFFECTIVE
IT WILL BE IN PICKING UP A SLOW-MOVING CLOSED-LOW OVER THE CENTRAL
PLAINS. THE ECMWF IS A BIT STRONGER WITH THE NORTHERN TROUGH AND
THUS PICKS UP MOST OF THE ENERGY FROM THE CLOSED-LOW. THE GFS IS
WEAKER WITH THE NORTHERN TROUGH AND STRUGGLES TO KICK OUT THE
CLOSED-LOW. BOTH SOLUTIONS BRING CHANCES OF PRECIP TO THE CWA...BUT
THE ECMWF SHOWS MUCH MORE COVERAGE. GIVEN HOW ANY SUBTLE DIFFERENCES
IN THE NORTHERN TROUGH COULD MEAN THE DIFFERENCE BETWEEN PICKING UP
THE LOW OR LEAVING IT BEHIND...HAVE OPTED TO CONTINUE CONSENSUS
CHANCE POPS FOR WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 128 PM EDT FRI SEP 19 2014
TIGHT PRESSURE GRADIENT AHEAD OF APPROACHING SURFACE TROUGH WILL
BRING GUSTY SOUTH WINDS TO ALL TERMINALS THROUGH THIS EVENING. FLOW
IS ESPECIALLY FAVORABLE FOR KSAW...AND EXPECT CONTINUED GUSTS TO
30KT OR PERHAPS HIGHER THERE INTO THE EARLY EVENING HOURS. OVERALL
COVERAGE AHEAD OF THE TROUGH HAS NOT BEEN EXTENSIVE...THEREFORE HAVE
KEPT VCSH IN FORECAST FOR IWD LATE THIS AFTERNOON WITH THE BETTER
CHANCE OF SHRA PUSHING IN DURING THE EVENING HOURS. AN ISOLATED
THUNDERSTORMS CANNOT BE RULED OUT WITH ELEVATED INSTABILITY OVER THE
AREA. OVERNIGHT TONIGHT...CONTINUED MOISTENING WILL OCCUR ALLOWING
EACH TAF SITE TO FALL TO IFR OR POSSIBLY EVEN LIFR CONDITIONS. WINDS
OVERNIGHT WILL DECREASE AS THE PRESSURE GRADIENT SHIFTS FARTHER EAST
AND MIXING DECREASES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT FRI SEP 19 2014
SOUTHERLY WINDS WILL INCREASE TODAY WITH LOW PRESSURE APPROACHING
FROM THE WEST AND HIGH PRESSURE JUST EAST OF LAKE SUPERIOR SHIFTING
EASTWARD. 20-30KT SOUTHERLY WINDS ARE EXPECTED ACROSS THE CENTRAL
AND EAST TODAY. A FEW GALES TO 35 KNOTS WILL BE POSSIBLE FOR THE
HIGHER PLATFORMS AND CLOSER TO THE UPPER MI SHORELINE. THE 20-30KT
SOUTH WINDS WILL GRADUALLY DIMINISH ACROSS THE EAST HALF OF THE LAKE
FRIDAY NIGHT THROUGH SATURDAY AS THE TROUGH MOVES ACROSS LAKE
SUPERIOR. EXPECT A PERIOD OF WESTERLY WINDS OF UP TO 20 KNOTS
SATURDAY AFTERNOON AND NW WINDS TO 20 KNOTS SUNDAY BEHIND THIS
TROUGH. WINDS WILL REMAIN UNDER 20 KNOTS THROUGH MUCH OF NEXT WEEK AS
A SERIES OF HIGH PRESSURE SYSTEMS MOVES OVER THE UPPER GREAT LAKES.
THE ONE EXCEPTION WILL BE THE CHANCE OF NORTH WINDS UP TO 25 KNOTS
MONDAY AFTERNOON AND EVENING BEHIND A QUICK-MOVING LOW PRESSURE
TROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...KEC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
353 PM CDT FRI SEP 19 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM CDT FRI SEP 19 2014
DURING THE SHORT TERM...CONFIDENCE ON SEEING MUCH ACTIVITY IN THE
MPX CWA THIS EVENING AND OVERNIGHT CONTINUES TO PLUMMET...BUT THIS
HAS BEEN OFFSET BY A SIGNIFICANT INCREASE IN CONFIDENCE FOR SEEING
THUNDERSTORMS SATURDAY AFTERNOON.
THIS AFTERNOON...A WARM FRONT HAD PUSHED UP TO ABOUT THE MN
RIVER...WITH A COLD FRONT EXTENDING FROM A SFC LOW NEAR THE
MN/ND/CAN BORDER TO THE SOUTH ACROSS THE ERN DAKOTAS. BAND OF LIGHT
RETURNS ON RADAR FROM WEST CENTRAL MN TOWARD DULUTH CORRELATES WELL
WITH FGEN THE RAP IS INDICATING IN THE H7-H6 LAYER ON THE NW SIDE OF
A RATHER STRONG CAPPING INVERSION. THIS CAPPING INVERSION LOOKS TO
KEEP THINGS IN CHECK THROUGH 00Z...BUT CAMS BEGIN TO SHOW THE CAP
BREAKING DOWN BETWEEN 00Z AND 03Z THIS EVENING. STORMS LOOK TO
INITIATE ALONG A PREFRONTAL TROUGH THAT IS CURRENTLY TAKING SHAPE
FROM DULUTH...DOWN THROUGH GLENCOE AND OFF TOWARD SIOUX FALLS. THIS
BOUNDARY CAN BE IDENTIFIED IN THE WIND FIELD...WITH STRONG SOUTHERLY
WINDS THAT HAVE BEEN GUSTING TO NEARLY 40 MPH ACROSS IA INTO SRN MN
TO THE EAST...AND MUCH LIGHTER WSW WINDS THAT ARE BACK ACROSS WRN
MN. BY THE TIME 3Z COMES AROUND...WHICH IS WHEN THE HRRR AND HOPWRF
SHOW STORMS INITIATING...SAID WIND SHIFT LOOKS TO BE SITTING NEAR A
FAIRMONT/HASTINGS/RICE LAKE LINE. ANY SORT OF SHORT WAVE TO HELP
KICK OF THUNDERSTORMS DOES NOT LOOK TO ARRIVE UNTIL AFTER 6Z...SO
LOOKS LIKE ISO-SCT STORM COVERAGE IS ABOUT THE BEST THE ERN FRINGE
OF THE MPX CWA CAN HOPE FOR...WITH MOST CAMS REALLY STARTING TO
HIGHLIGHT THE GREATEST STORM COVER BEING DOWN IN IOWA...WHERE BETTER
INSTABILITY WILL RESIDE. GIVEN TREND IN SHORT TERM MODELS...
CONTINUED TO REDUCE POPS/QPF THIS EVENING...AND ALSO SPED UP THE
EWD PROGRESSION OF THE DRY WEATHER AS ALL CAMS SHOW ANY ACTIVITY
THAT DOES DEVELOP THIS EVENING BEING EAST OF THE MPX CWA BY 9Z. THE
ONLY THING TO WATCH OUT FOR WITH POPS FOR LATE TONIGHT INTO SATURDAY
MORNING IS THE NAM DOES SHOW A REGION OF MID LEVEL FGEN WORKING
ACROSS SOUTH CENTRAL MN AS A SHORTWAVE FINALLY WORKS ACROSS SRN MN.
HOWEVER...THIS WOULD NOT BE ANYTHING TOO SERIOUS AND WOULD BE POST
FRONTAL AND NO WORSE THAN WHAT WE ARE SEEING ACROSS CENTRAL MN THIS
AFTERNOON.
FOR SATURDAY WE WILL SEE A BREAK IN THE ACTION THROUGH THE
MORNING...BUT THE STRONG SHORTWAVE AND ASSOCIATED JET STREAK
CURRENTLY MOVING INTO WRN ALBERTA WILL BE DIVING SE ACROSS NRN MN BY
SATURDAY AFTERNOON. THERE IS GOOD AGREEMENT BETWEEN THE
DETERMINISTIC MODELS AND CAMS WITH A LINE OF STORMS DIVING SE OUT OF
NRN MN DURING THE AFTERNOON OUT AHEAD OF THE WAVES PV FEATURE AND AT
THE NOSE OF A 120+ KT NWRLY JET STREAK. GIVEN STRONG MODEL
AGREEMENT...INCREASED POPS SIGNIFICANTLY SATURDAY AFTERNOON FROM THE
LOW CHANCE CATEGORY TO KNOCKING ON THE DOOR OF GOING CATEGORICAL.
MAIN QUESTION IS HOW FAR SW WILL WE SEE ACTIVITY. GIVEN THE TRACK OF
THE PV ANOMALY AND JET STREAK...FORCING FROM THOSE FEATURES LOOKS TO
BE CENTERED ALONG AND NORTH OF THE I-94 CORRIDOR...BUT SREF PROBS
AND CAM REFLECTIVITY FORECASTS DO SHOW THE LINE TAILING BACK INTO SW
MN...SO DID DRAG POPS AS FAR SW AS THE MN RIVER. FOR THE SEVERE
THREAT...THE BIG LIMITING FACTOR WILL BE THE MEAGER INSTABILITY
/MUCAPE AROUND 500 J/KG/ AND WEAK MID-LEVEL LAPSE RATES.
HOWEVER...FORECAST SOUNDINGS SHOW WINDS OF 50 KTS OR MORE GETTING
DOWN TO NEAR 10K FEET. WITH THE CAMS SHOWING A NICE LINE OF STORMS
DEVELOPING...COULD SEE THESE STORMS BE ABLE TO TRANSFER SOME OF THIS
MOMENTUM TO THE GROUND...WHICH WILL POSE A RISK FOR DAMAGING
WINDS...BUT THE LACK OF INSTABILITY AND WEAK MID-LEVEL LAPSE RATES
SHOULD KEEP ANY HAIL SIZES IN CHECK.
NOT MANY CHANGES WERE MADE TO THE REST OF THE FORECAST...OTHER THAN
TO COOL HIGHS TOMORROW SOME WHERE WE HAVE LIKELY POPS IN THE
AFTERNOON...AS THE ARRIVAL OF CLOUD COVER AND RAIN LOOKS TO PUT AN
EARLIER END TO DIURNAL RISES IN THOSE LOCATIONS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM CDT FRI SEP 19 2014
ANY THUNDERSTORM ACTIVITY ONGOING AT THE BEGINNING OF THE PERIOD
WILL BE QUICK TO SWING EAST THANKS TO THE VERY FAST 90-130 KT
UPPER LEVEL FLOW CONTRIBUTING TO THE SOUTHEASTWARD DIGGING TROUGH.
CYCLONIC FLOW WILL REMAIN OVER PORTIONS OF CENTRAL AND EASTERN
WISCONSIN INTO SUNDAY AND MAY ALLOW FOR A FEW SHOWERS TO DEVELOP
IN THE AFTERNOON. HOWEVER...THE SURFACE RIDGE BUILDING EAST INTO
THE PLAINS WILL KEEP THE REMAINING AREAS DRY AND MAINLY CLEAR. THE
TROUGH WILL LIFT OUT BY MONDAY WITH SEASONAL TEMPS AND CLEAR SKIES
ACROSS THE ENTIRE UPPER MIDWEST THROUGH EARLY NEXT WEEK.
A MAJOR PATTERN SHIFT WILL TAKE PLACE NEXT WEEK AND LIKELY PERSIST
THROUGH THE REST OF SEPTEMBER. THE SURFACE HIGH WILL MAKE STEADY
PROGRESS EAST AND EVENTUALLY PARK ITSELF OVER NEW ENGLAND FOR
MIDWEEK AND BEYOND. MEANWHILE...MID LEVEL HEIGHTS WILL BUILD OVER
THE MIDWEST WITH THE CENTER LOCATED SOMEWHERE NEARBY FOR LATE WEEK
AND NEXT WEEKEND. THIS WILL ALLOW FOR A WARMER AND DRIER THAN
NORMAL PATTERN TO SET UP FOR A GOOD PORTION OF THE LONG TERM.
THERE WILL BE A BRIEF HIATUS IN THIS EVOLUTION MIDWEEK AS LOW
LEVEL MOISTURE INCREASES AND A DISTURBANCE LIFTS NORTH UP AND
AROUND THE BUILDING RIDGE FROM THE DESERT SOUTHWEST /CURRENTLY
LOCATED OVER CALIFORNIA/. CLOUDS AND SCATTERED SHOWERS/THUNDERSTORMS
WILL KEEP TEMPERATURES DOWN A BIT TUESDAY AND WEDNESDAY. WITH THE
BUILDING MID LEVEL HEIGHTS...MID LEVEL LAPSE RATES WILL BE RATHER
MEAGER WHICH WILL LIMIT ANY SEVERE THREAT GREATLY. KEPT POPS LOW
DUE TO THE LACK OF INSTABILITY AND A SLOW WEAKENING/ABSORPTION OF
THE SYSTEM INTO THE ZONAL FLOW ACROSS CANADA.
AS MENTIONED ABOVE...THE MID LEVEL RIDGE WILL LIKELY BE CENTERED
OVER THE MIDWEST BY NEXT WEEKEND. SUMMERLIKE TEMPERATURES SHOULD
MAKE A RETURN AS 850 MB TEMPS REACH BETWEEN +15 TO +20C. SINCE THE
MAJORITY OF SOUTHERN MINNESOTA DID NOT HAVE A HARD TIME REACHING
THE LOWER/MIDDLE 80S TODAY...WE STAND A PRETTY GOOD CHANCE AT
REACHING THE 80S AGAIN LATE NEXT WEEK WITH A STRONGER RIDGE AND
WARMER TEMPS ALOFT. DRY WEATHER WILL PREVAIL UNTIL THE WESTERN
TROUGH BEGINS TO ADVANCE EASTWARD - NOT UNTIL WELL AFTER THE
CURRENT FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1252 PM CDT FRI SEP 19 2014
ALL SHORT TERM GUIDANCE HAS BEEN PERSISTENT WITH ANY TSRA ACTIVITY
REMAINING SE OF ALL TERMINALS THIS EVENING...SO REMOVED ANY
REMAINING VC MENTIONS WITH THE 18Z TAFS. MEANS ONLY CONCERN IS THE
EVOLUTION OF THE MVFR CIGS THIS AFTERNOON. THESE CIGS HAVE BEEN
RAPIDLY ERODING AWAY FROM THE SOUTH...AND THE RAP LOOKS TO HAVE A
GOOD HANDEL ON HOW THEY ARE ERODING AWAY...SO FOLLOWED IT TO TIME
CIG IMPROVEMENTS IN TAFS. MAY SEE MVFR CIGS TRY TO REFORM THIS
EVENING AS THE PREFRONTAL MOISTURE POOL MOVES INTO WI...BUT THE
HRRR ALONG WITH THE SREF ARE NOT VERY AGGRESSIVE WITH BUILDING
LOWER CIGS BACK IN UNTIL THE DEEPER MOISTURE MOVES OFF TO THE EAST
OF EAU...SO JUST WENT WITH A SHORT WINDOW OF MVFR CIGS...SIMILAR
TO WHAT THE HRRR HAS. WILL LOOSE GUSTY WINDS THIS EVENING AS THEY
VEER OVER TO THE WNW OVERNIGHT. PRECIP IS BEGINNING TO LOOK
LIKELY SATURDAY AFTERNOON...BUT TIMING AFTER 18Z MAKES THEM A
PROBLEM FOR THE 00Z TAF FORECASTER TO FIGURE OUT.
KMSP...
MAY SEE OCCASIONAL MVFR CIGS THROUGH 20Z AS MOISTURE WORKS IN FROM
THE WEST. HOWEVER...AS THESE CLOUDS ARRIVE...THEY ARE BREAKING UP
PRETTY FAST FROM THE SOUTH. AT ANY RATE...WITH THE FIELD
OPERATING ON THE 12S...THERE REALLY IS NOT MUCH OF AN
OPERATIONS IMPACT DIFFERENCE BETWEEN AN 025 AND AN 040 FOR THE CIG.
CONFIDENCE IS HIGH THAT THERE WILL BE NO THUNDER THIS EVENING AT
MSP GIVEN THE STRENGTH OF THE CAPPING INVERSION...WITH IT NOT
LOOKING TO BREAK DOWN UNTIL THE FRONT IS WELL SE OF THE FIELD.
CONFIDENCE IS MUCH HIGHER IN SEEING SHRA/TSRA SAT AFTERNOON. DEBATED
PUTTING IN A -SHRA WITH THE 20/2200 GROUP...BUT AT 28 HOURS
OUT...WE HAVE PLENTY OF TIME TO WORK THAT INTO THE TAF WHEN.
/OUTLOOK FOR KMSP/
SUN...VFR. WINDS NW 10-15 KTS.
MON...VFR. WINDS W 5-10 KTS.
TUE...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...BORGHOFF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
308 PM CDT FRI SEP 19 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 308 PM CDT FRI SEP 19 2014
UPPER LEVEL JET AXIS OVER THE FA AT 19Z WILL BE MOVING E OF THE AREA
BY 00Z AND TAKING ITS UPPER SUPPORT WITH IT. MEANWHILE...A SERIES OF
VORT MAXES WAS ALSO AFFECTING THE FA. THIS COMBO WAS DRIVING THE
RAIN OVER MUCH OF THE AREA THIS AFTERNOON. AT THE SFC...A WARM FRONT
WAS PUSHING THROUGH THE FA AS SEEN IN SFC TEMPS RISING EVEN UNDER
THE CLOUD SHIELD. A COLD FRONT WAS REACHING EASTERN ND AT 19Z AND
WILL BE THE FOCUS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND ESPECIALLY TONIGHT. APPEARS ATTM THAT A CLEARING TREND
MAY OCCUR FOR A TIME LATE THIS AFTERNOON. HOWEVER...CLOUDS WILL
QUICKLY DEVELOP ALONG AND AHEAD OF THE FRONT AND FILL IN. GUSTY SFC
WINDS WILL CONTINUE UNTIL SUNSET WHEN LOW LEVEL INVERSION SETS UP.
THE COLD FRONT IS EXPECTED TO BISECT THE FA FROM N TO S BY 06Z.
SHOWERS AND STORMS WILL INITIATE ALONG AND AHEAD OF THE FRONT. BEST
UPPER LEVEL SUPPORT WILL BE ALONG THE INTERNATIONAL BORDER WHERE A
VORT MAX WILL BE DRIFTING THROUGH...AND IN NW WI WHERE UPPER LEVEL
DIVERGENCE WILL BE ENHANCED DUE TO A DEPARTING JET LET. ATTEMPTED TO
ALIGN POPS TO ACCOUNT FOR THESE FEATURES. THE FRONT IS PROGGED TO
REACH THE EASTERN EDGE OF THE WI FA BY 12Z SATURDAY. A DRYING TREND
WILL FOLLOW BEHIND THE FRONT WITH WEAK SFC RIDGING. TRENDED POPS
DOWNWARD AFTER 06Z.
THE FRONT COMPLETELY EXITS SATURDAY MORNING ALLOWING THE SFC RIDGING
TO COVER THE FA BY 15Z. LEFT SOME POPS OVER THE EASTERN EDGE OF THE
AREA FOR ANY LEFTOVER RAIN. HAVE NO RAIN MENTIONED FROM 15Z TO 18Z
SATURDAY. AFTER 18Z...BEGIN TO RAMP THINGS UP AS A DIGGING UPPER
LEVEL TROF DRIVES ANOTHER COLD FRONT THROUGH THE FA. FORCING IS
MAXIMIZED BY MID AFTERNOON AS THE NOSE OF AN UPPER LEVEL JET
ARRIVES. HAVE POPS OVER THE ENTIRE AREA AFTER 21Z WITH THE HIGHEST
OVER THE MN ZONES. SOME STORMS MAY BE ON THE STRONG SIDE IN THE MID
AFTERNOON AS THERMODYNAMIC PROFILES SUGGEST. MUCAPE APPROACHES 500
J/KG BUT INSTABILITY AXIS IS OVER THE SOUTHERN MN ZONES. WILL LEAVE
OUT THE MENTION FOR NOW AS CONFIDENCE IS LOW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 308 PM CDT FRI SEP 19 2014
A COLD FRONT AND SHORTWAVE WILL CONTINUE TO MOVE THROUGH THE
NORTHLAND SATURDAY NIGHT WITH A CHANCE FOR SHOWERS AND STORMS. SOME
OF THE STORMS COULD BE QUITE STRONG EARLY IN THE EVENING WITH STRONG
FORCING ALONG THE FRONTAL BOUNDARY. WE HAVE POPS HIGHEST OVER OUR
CENTRAL/EASTERN ZONES IN THE EVENING. THE FORCING WILL PARTIALLY
MAKE UP FOR A LACK OF INSTABILITY AND MARGINAL SHEAR.
HIGH PRESSURE WILL START TO BUILD IN ON SUNDAY AND MOST AREAS WILL
BE DRY. THERE MAY BE SOME LINGERING SHOWERS OVER EASTERN AREAS...BUT
ANY SHOWERS SHOULD BE LIGHT.
HIGH PRESSURE WITH RIDGING ALOFT WILL KEEP THE NORTHLAND DRY SUNDAY
NIGHT THROUGH TUESDAY. A TROUGH WILL THEN START TO IMPACT THE AREA
TUESDAY NIGHT INTO THURSDAY NIGHT WITH A CHANCE FOR SHOWERS/STORMS.
HIGHS SUNDAY WILL BE IN THE UPPER FIFTIES TO MIDDLE SIXTIES...THEN
BE IN THE SIXTIES THROUGH MID WEEK. HIGHS LATE IN THE WEEK LOOK TO
REBOUND INTO THE LOWER TO MIDDLE SEVENTIES FOR MUCH OF THE
NORTHLAND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM CDT FRI SEP 19 2014
IFR/MVFR CONDITIONS COVERED MUCH OF THE NORTHLAND...WITH THE
EXCEPTION OF A PORTION OF NORTHWEST WISCONSIN. THE RAP HAS A
FAIRLY GOOD GRASP ON THESE LOWER CEILINGS AND GRADUALLY DIMINISHES
THEM FROM THE SOUTH TO THE NORTH. THE LATEST VISIBLE SATELLITE
IMAGERY SUPPORTS THIS TREND AS WELL. SHOWERS AND A FEW
THUNDERSTORMS WILL CONTINUE TO MOVE ACROSS THE NORTHLAND THIS
AFTERNOON AHEAD OF A COLD FRONT THAT WAS IN EASTERN NORTH DAKOTA
EARLY THIS AFTERNOON. COVERAGE OF THE SHOWERS/STORMS WILL
DIMINISH FOR MOST AREAS LATE THIS AFTERNOON INTO THE EVENING.
HOWEVER...AS THE FRONT MOVES SOUTHEAST WE EXPECT MORE TO FORM. FOG
WILL ALSO OCCUR IN SPOTS THROUGH THE PERIOD. CONDITIONS FOR MOST
AREAS WILL IMPROVE TO VFR ON SATURDAY. ANOTHER POTENT FRONTAL
BOUNDARY AND SHORTWAVE WILL IMPACT THE NORTHLAND AFTER THE TAF
PERIOD...AND WILL BRING A CHANCE FOR SHOWERS/STORMS AND MVFR
CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 58 67 51 61 / 40 60 70 20
INL 52 64 47 59 / 60 80 70 10
BRD 57 69 49 67 / 20 60 20 10
HYR 59 68 49 64 / 50 60 60 20
ASX 58 68 50 60 / 50 40 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
130 PM CDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT FRI SEP 19 2014
THE RAIN THAT WE`VE BEEN TALKING ABOUT ALL WEEK IS FINALLY ON OUR
DOORSTEP...HOWEVER...STRONG WARM ADVECTION WILL ACT TO CAP THE
ATMOSPHERE TODAY AND KEEP DEEP MOIST CONVECTION AT A MINIMUM UNTIL
THIS EVENING ACROSS PORTIONS OF SOUTHERN MN AND WI. THETA-E
ADVECTION IS GOING STRONG IN THE DAKOTAS EARLY THIS MORNING AND
THE RESULT IS A HEALTHY BATCH OF SHOWERS AND THUNDERSTORMS THAT
CONTINUE TO SLOW CREEP EAST WITH TIME. MODEST MUCAPE AND GOOD MID-
LEVEL LAPSE RATES HAVE LEAD TO A COUPLE STRONGER CORES IN THE ABR
FORECAST AREA AND EVEN A LATE NIGHT SEVERE THUNDERSTORM WARNING
FOR ONE PARTICULARLY STRONG ELEVATED THUNDERSTORM. WE THINK THE
SOUTHERN EXTENT OF THESE SHOWERS /ROUGHLY GETTYSBURG-BOWDLE/ WILL
ALSO REPRESENT THE LATITUDINAL SOUTHERN EXTENT IN MN LATE THIS
MORNING AND EARLY AFTERNOON IN WESTERN WI. THEREFORE...NEARLY ALL
OF THE SHOWERS AND EMBEDDED THUNDER SHOULD BE WELL NORTH OF
I-94...CLOSER TO THE UPPER JET AND COOLER MID LEVEL TEMPS. THERE
SHOULD STILL BE PLENTY OF CLOUD COVER...BUT WE REALLY DON`T EXPECT
MUCH IN THE WAY OF RAIN BEFORE 00Z.
AS THE COLD FRONT APPROACHES...THE SHORT RANGE GUIDANCE AND
EXTRAPOLATION OF CURRENT TRENDS SUGGEST WE SHOULD BUILD IN A
TONGUE OF MODEST MLCAPE /800-1500 J/KG/ BETWEEN 21-03Z ACROSS
SOUTHERN MN. THIS INSTABILITY WILL COINCIDE WITH INCREASING
WESTERLY 0-6KM SHEAR VECTORS BY 00Z. THE TEMPERATURE GRADIENT
ACROSS THE ADVANCING COLD FRONT IS NOT VERY GOOD...SO THERE SHOULD
BE LITTLE IN THE WAY OF A FRONTAL CIRCULATION TO HELP INITIATE
CONVECTION. THERE WILL BE MECHANICAL LIFTING ALONG THE FRONT AND
EASTWARD ADVANCING 20-50M 12-HR FALLS WITH THE SHORTWAVE. WE
DEFINITELY THINK THERE IS ENOUGH SUPPORT FOR SCATTERED
THUNDERSTORM DEVELOPMENT...BUT CONFIDENCE IS STILL NOT HIGH THAT
WIDESPREAD OR NUMEROUS STORMS WILL BREAK OUT ALONG THE FRONT. THIS
MORNING`S CAM GUIDANCE SHOWS MORE WIDESPREAD THUNDERSTORM ACTIVITY
AS THE FORCING EXITING THE FORECAST AREA. THIS WOULD SUGGEST
BETTER STORM COVERAGE IN EASTERN IA...SOUTHEAST MN AND SW WI.
THERE REMAINS A MARGINAL HAIL AND WIND THREAT ACROSS SOUTHERN MN
THIS EVENING. SYNTHETIC REFLECTIVITY OF THE CAMS SUGGEST MULTI-
CELL AND/OR LINEAR STORM STRUCTURE FROM 02-06Z ALONG THE
SOUTHERN AND EASTERN FRINGES OF THE FORECAST AREA. GIVEN THE
STRONG WESTERLY FLOW ALOFT...IT`S POSSIBLE A COUPLE OF THESE
STORMS WILL GET STRONG ENOUGH CORES TO TRANSFER SOME OF THIS
MOMENTUM DOWN TO THE GROUND. THE 24-HR CIPS /VALID AT 20.00Z/
ANALOGS FROM THE 19.00Z NAM SUGGEST 30-40% OF AT LEAST ONE SEVERE
REPORT WITH THE TOP ANALOGS FAVORING MARGINALLY SEVERE HAIL IN
WESTERN MN AND THE DAKOTAS...AND MORE WIND REPORTS IN SOUTHERN MN
AND IA. THIS MAKES SENSE BASED ON THE EXPECTED EVOLUTION OF
CONVECTION TODAY. AS MENTIONED ABOVE...WE ALREADY SAW A NICE
ELEVATED IN SD THIS MORNING...SO THAT MATCHES THE CIPS SIGNAL FOR
HAIL OUT WEST. ALL THAT SAID...WOULD DOUBT WE NEED A WATCH TODAY
LOCALLY...BUT WOULDN`T BE TOTALLY SURPRISED TO SEE A WARNING OR
TWO COME OUT OF THIS OFFICE LATER ON THIS EVENING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI SEP 19 2014
SATURDAY...THE LONGWAVE TROUGH AXIS WILL PASS THRU THE UPR MISS
RIVER VALLEY SAT MRNG...PUSHING ALONG A SFC CDFNT THRU THE REGION.
MEAGER UPR LEVEL SUPPORT FOR TSTMS BUT THERE MAY WELL BE SOME
LINGERING SHWRS ALONG AND IMMEDIATELY POST-FRONT SHORTLY AFTER
DAYBREAK AS MOISTURE WILL STILL BE FAIRLY DEEP WITH POCKETS OF PVA
INVOF THE CDFNT. ONCE THIS TROUGH AXIS PUSHES THRU...A SHORT BREAK
IN THE ACTION IS EXPECTED THRU MIDDAY BUT THIS IS AHEAD OF A
RAPIDLY-DROPPING SHORTWAVE TROF AXIS FROM CENTRAL CANADA. WITHIN
NW FLOW ALOFT...A CUTOFF LOW ALOFT WILL DEVOLVE INTO AN OPEN WAVE
BUT NOT BEFORE ARRIVING WITH A POST-FRONTAL SFC TROUGH AND
CONTINUED DEEP MOISTURE OVER THE AREA SAT AFTN. DECENT DIVERGENCE
ALOFT WITH WEAK-MODERATE SFC CONVERGENCE LOOKS TO SPARK OFF SOME
ISOLD-SCATTERED SHOWERS SAT AFTN AND EVE FOR NE AND E PORTIONS OF
THE WFO MPX CWFA. THE UPR LEVEL FEATURE WILL DRIVE INTO SRN-ERN WI
SAT NIGHT...ENDING ANY FURTHER CONCERN FOR PRECIP AND HELPING DEEP
DRY NW FLOW TO TAKE HOLD.
SUNDAY THROUGH TUESDAY...A LARGE WRN CONUS RIDGE WILL BUILD
FURTHER SUNDAY AND SPREAD ACRS THE ROCKIES GOING INTO MONDAY WHILE
AN UPR LVL LOW IS SUPPRESSED ON THE WRN FRINGES OF THE RIDGE OVER
CA/NV. THE UPR RIDGE WILL ALLOW COOLER/DRIER CANADIAN SFC HIGH
PRES TO DROP INTO THE NRN-CENTRAL PLAINS SUN...SPREADING EWD MON
INTO THE UPR-MID MISS RIVER VALLEY REGION AND THE OHIO VALLEY
REGION. THE SFC HIGH PRES AND RIDGE ALOFT PATTERN WILL SLOWLY
SHIFT E ACRS THE REGION MON INTO TUE...KEEPING THE AREA WITH
SEASONABLE TEMPERATURES AND NO PRECIP. HOWEVER...THE UPR LVL LOW
OVER THE WRN STATES WILL SLOWLY SHIFT EWD BEHIND THE UPR RIDGE...
BECOMING A SHORTWAVE TROUGH OVER THE N-CENTRAL STATES BY MIDDAY
TUE. ITS SLOW WWD PROGRESS SPELLS NO PRECIP EXPECTED DURING THE
FIRST FEW DAYS OF NEXT WEEK.
WEDNESDAY THROUGH THURSDAY...THE AFOREMENTIONED SHORTWAVE TROUGH
NOW EXPECTED TO TRAVERSE THE NRN STATES DURG THE MIDDLE OF NEXT
WEEK MEANS A PATTERN CHANGE COMPARED TO THE PERSISTENT RIDGING AT
THE SFC AND ALOFT ORIGINALLY EXPECTED THE FAST FEW DAYS. IN TERMS
OF SENSIBLE WX...DESPITE WEAK SFC SUPPORT...FLOW ALOFT WILL SHAKE
THE ATMOS UP ENOUGH SUCH THAT ISOLD TO SCATTERED SHOWERS AND A FEW
TSTMS CAN BE EXPECTED ACRS THE AREA WED INTO THU. NOT LOOKING FOR
A LOT OF COVERAGE NOR QPF ATTM. TEMPERATURES WILL GENERALLY RUN
WITHIN A FEW DEGREES OF NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1252 PM CDT FRI SEP 19 2014
ALL SHORT TERM GUIDANCE HAS BEEN PERSISTENT WITH ANY TSRA ACTIVITY
REMAINING SE OF ALL TERMINALS THIS EVENING...SO REMOVED ANY
REMAINING VC MENTIONS WITH THE 18Z TAFS. MEANS ONLY CONCERN IS THE
EVOLUTION OF THE MVFR CIGS THIS AFTERNOON. THESE CIGS HAVE BEEN
RAPIDLY ERODING AWAY FROM THE SOUTH...AND THE RAP LOOKS TO HAVE A
GOOD HANDEL ON HOW THEY ARE ERODING AWAY...SO FOLLOWED IT TO TIME
CIG IMPROVEMENTS IN TAFS. MAY SEE MVFR CIGS TRY TO REFORM THIS
EVENING AS THE PREFRONTAL MOISTURE POOL MOVES INTO WI...BUT THE
HRRR ALONG WITH THE SREF ARE NOT VERY AGGRESSIVE WITH BUILDING
LOWER CIGS BACK IN UNTIL THE DEEPER MOISTURE MOVES OFF TO THE EAST
OF EAU...SO JUST WENT WITH A SHORT WINDOW OF MVFR CIGS...SIMILAR
TO WHAT THE HRRR HAS. WILL LOOSE GUSTY WINDS THIS EVENING AS THEY
VEER OVER TO THE WNW OVERNIGHT. PRECIP IS BEGINNING TO LOOK
LIKELY SATURDAY AFTERNOON...BUT TIMING AFTER 18Z MAKES THEM A
PROBLEM FOR THE 00Z TAF FORECASTER TO FIGURE OUT.
KMSP...
MAY SEE OCCASIONAL MVFR CIGS THROUGH 20Z AS MOISTURE WORKS IN FROM
THE WEST. HOWEVER...AS THESE CLOUDS ARRIVE...THEY ARE BREAKING UP
PRETTY FAST FROM THE SOUTH. AT ANY RATE...WITH THE FIELD
OPERATING ON THE 12S...THERE REALLY IS NOT MUCH OF AN
OPERATIONS IMPACT DIFFERNCE BETWEEN AN 025 AND AN 040 FOR THE CIG.
CONFIDENCE IS HIGH THAT THERE WILL BE NO THUNDER THIS EVENING AT
MSP GIVEN THE STRENGTH OF THE CAPPING INVERSION...WITH IT NOT
LOOKING TO BREAK DOWN UNTIL THE FRONT IS WELL SE OF THE FIELD.
CONFIDENCE IS MUCH HIGHER IN SEEING SHRA/TSRA SAT AFTERNOON. DEBATED
PUTTING IN A -SHRA WITH THE 20/2200 GROUP...BUT AT 28 HOURS
OUT...WE HAVE PLENTY OF TIME TO WORK THAT INTO THE TAF WHEN.
/OUTLOOK FOR KMSP/
SUN...VFR. WINDS NW 10-15 KTS.
MON...VFR. WINDS W 5-10 KTS.
TUE...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
1241 PM CDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 910 AM CDT FRI SEP 19 2014
MAIN CHANGE WAS TO ADD A MENTION OF FOG ALONG THE NORTH SHORE FROM
SILVER BAY TO GRAND PORTAGE. CKC CONTINUES TO CARRY BR WITH VSBYS
IMPROVING. RAIN SHIELD HAS REACHED THE WESTERN FA AS OF 14Z. MADE
SOME MINOR ADJUSTMENTS FOR THE LATEST TRENDS.
UPDATE ISSUED AT 649 AM CDT FRI SEP 19 2014
ADDED AREAS OF FOG/DRIZZLE ALONG ELEVATED TERRAIN OF COOK COUNTY.
LOW LVL COND PRESS DEFICITS HAVE DROPPED TO LESS THAN 10 MB DUE
TO TERRAIN LIFT OF LONG-FETCHED BDRY LYR FLOW.
&&
.SYNOPSIS...
ISSUED AT 339 AM CDT FRI SEP 19 2014
A STRONG WARM ADVECTION REGIME CONTINUES OVER THE CWA EARLY THIS
MORNING. EXTENSIVE LOW STRATUS IS LOCATED FROM NEAR THE TWIN PORTS
NORTH INTO THE ARROWHEAD. ALOFT...A LARGE AREA OF MID LVL CLOUD
COVER IS ADVECTING EAST ACROSS NE MN INTO NWRN WISC. A MIGRATORY
SHORTWAVE TROF IS MOVING ALONG THE TOP OF THE MID LVL RIDGE OVER THE
NRN PLAINS. ASSOCIATED 60/65KT LLJ HAS TRANSLATED INTO NWRN ONTARIO
WHERE AN AREA OF CONVECTION IS LOCATED. WEAK RADAR RETURNS ARE
DEVELOPING WEST OF CWA AND WILL BRING A FEW SHOWERS INTO WRN CWA
BEFORE DAWN. THIS AREA OF SHOWERS APPEARS TO BE LINKED TO AN
EXTENSION OF THE 85H MSTR TRANSPORT MAXIMUM STRETCHING SOUTH FROM
ONTARIO.
&&
.SHORT TERM...(TODAY AND TOMORROW)
ISSUED AT 339 AM CDT FRI SEP 19 2014
TODAY...PROGRESSIVE SHORTWAVE WILL DRAG LLJ AXIS EASTWARD ACROSS THE
REGION. GENERAL IDEA IS THAT HIGHEST POPS WILL OCCUR OVER NWRN CWA
THRU 18Z...AND THEN SHIFT ACROSS ARROWHEAD AND ERN CWA DURING THE
AFTN HRS. CONVECTIVE POTENTIAL IS LIMITED BASED ON FCST MLCAPE AND
MUCAPE FIELDS ALTHOUGH DEEP LAYER SHEAR IS QUITE SUFFICIENT TO
PROMOTE ORGANIZATION IF CELLS WERE TO DEVELOP. A SIGNIFICANT
AMOUNT OF CIN IS DEPICTED IN ELEVATED CAPE AREAS SO IT MAY BE
TOUGH TO GET MUCH DEVELOPMENT. MOST LIKELY POTENTIAL DEVELOPS
AFTER 00Z OVER WCTRL CWA.
TONIGHT..A NARROW WINDOW OF CONVECTIVE POTENTIAL OCCURS FROM CASS
LAKE TO TWIN PORTS 03Z-06Z AS MUCAPES OF NEAR 1500 J/KG ALIGN WITH
45KT 0/6KM SHEAR. AFTER 06Z...THERE IS A POTENTIAL FOR ADDITIONAL
CONVECTION TO MOVE QUICKLY SE ACROSS HYR LAKES VICINITY INTO PRICE
COUNTY. REGARDING THE OVERALL BDRY LYR CONVERGENCE ...IT IS NOT VERY
ORGANIZED AND UNIDIRECTIONAL FLOW IS FORECAST WITHIN THE LOWEST 5K
FEET. OTHERWISE THE FRONTAL BDRY WILL SWING ACROSS CWA WITH
WIND SHIFT TO W AND NW AND MOMENTUM TRANSFER INCREASING. HIGHER POPS
REMAIN ALONG INTL BORDER THROUGH 06Z...CLOSER TO DEEPER CYCLONIC
CURVATURE UNDERNEATH AMPLIFYING MID LVL TROF.
SATURDAY..INTERESTING PATTERN AS INITIAL FORCING MOVES EAST OF
REGION WITH A BRIEF BREAK IN PRECIP OVER MOST OF WRN/CTRL CWA. A
STRONG SHORTWAVE WILL RAVE INTO THE REGION BY AFTN WITH INSTABILITY
DEVELOPING AS LAPSE RATES STEEPEN DUE TO BDRY LYR WARMING AND
COOLING ALOFT. SREF CPTP INDICATES MDT PROB OF THUNDER OVER MOST OF
THE NE MN ZONES THROUGH 21Z...AND FARTHER SOUTHEAST THROUGH 03Z. A
NARROW AXIS OF LOW LVL THERMAL RIDGING AHEAD OF THE APPROACHING TROF
MAY ALLOW TEMPS TO CLIMB QUICKLY OVER SRN CWA TO LOW TO MID 70S SO
FCST TEMPS MAY NEED TO BE ADJUSTED UPWARDS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 339 AM CDT FRI SEP 19 2014
A VORT MAX ASSOCIATED WITH A H50 TROUGH AXIS WILL DROP OVER THE
WESTERN LAKE SUPERIOR REGION SATURDAY NIGHT INTO SUNDAY MORNING.
THE UNSTABLE CYCLONIC FLOW AND COOLING ALOFT WILL KEEP A CHC FOR
SHOWERS AND A FEW THUNDERSTORMS OVER MUCH OF THE NORTHLAND DURING
THIS TIME. A BROAD AREA OF UPPER LVL RIDGING BUILDS INTO THE
CENTRAL CONUS MONDAY...GRADUALLY SHIFTING EAST...CENTERING OVER
THE GREAT LAKES/OHIO RIVER VALLEY...THROUGH MID-WEEK. THE RIDGE
AND ASSOCIATED SFC HIGH WILL KEEP THE FCST DRY WITH SEASONABLE
TEMPERATURES FOR THE FIRST HALF OF THE WORK WEEK.
FOCUS TURNS TO A SHORT WAVE THAT TRANSLATES ACROSS THE DAKOTAS...AND
INTO NW MINNESOTA TUESDAY NIGHT/WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES IN THE TIMING AND STRENGTH OF THE WAVE AS IT TRACKS OVER
THE NORTHLAND. ATTM...CARRYING BROAD BRUSH SCHC POPS WED NIGHT AND
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM CDT FRI SEP 19 2014
IFR/MVFR CONDITIONS COVERED MUCH OF THE NORTHLAND...WITH THE
EXCEPTION OF A PORTION OF NORTHWEST WISCONSIN. THE RAP HAS A
FAIRLY GOOD GRASP ON THESE LOWER CEILINGS AND GRADUALLY DIMINISHES
THEM FROM THE SOUTH TO THE NORTH. THE LATEST VISIBLE SATELLITE
IMAGERY SUPPORTS THIS TREND AS WELL. SHOWERS AND A FEW
THUNDERSTORMS WILL CONTINUE TO MOVE ACROSS THE NORTHLAND THIS
AFTERNOON AHEAD OF A COLD FRONT THAT WAS IN EASTERN NORTH DAKOTA
EARLY THIS AFTERNOON. COVERAGE OF THE SHOWERS/STORMS WILL
DIMINISH FOR MOST AREAS LATE THIS AFTERNOON INTO THE EVENING.
HOWEVER...AS THE FRONT MOVES SOUTHEAST WE EXPECT MORE TO FORM. FOG
WILL ALSO OCCUR IN SPOTS THROUGH THE PERIOD. CONDITIONS FOR MOST
AREAS WILL IMPROVE TO VFR ON SATURDAY. ANOTHER POTENT FRONTAL
BOUNDARY AND SHORTWAVE WILL IMPACT THE NORTHLAND AFTER THE TAF
PERIOD...AND WILL BRING A CHANCE FOR SHOWERS/STORMS AND MVFR
CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 64 58 68 52 / 60 50 60 30
INL 69 54 65 47 / 70 70 60 70
BRD 68 58 71 49 / 60 20 40 10
HYR 66 61 70 49 / 60 50 40 30
ASX 67 60 68 50 / 60 50 30 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ140-
141.
&&
$$
UPDATE...GSF
SYNOPSIS...CANNON
SHORT TERM...CANNON
LONG TERM...GRANING
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS JACKSON MS
351 PM CDT FRI SEP 19 2014
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...CONVECTION HAS BEEN
SLOW TO GENERATE ACROSS THE CWA THIS AFTERNOON...BUT SURFACE ANALYSIS
AND VIS IMAGERY HAS REVEALED A NORTH-SOUTH CONVERGENT AXIS/TROF
BISECTING MS AT THE MOMENT. SPARSE CONVECTION HAS DEVELOPED ALONG
THIS AXIS AS WELL AS SOME SLIGHTLY BETTER COVERAGE IN THE SOUTH WHERE
BROADER CONVERGENCE IS OCCURRING. WESTWARD MOVING CONVECTIVE AREA
OVER AL IS A LITTLE CONCERNING FOR EASTERN SECTIONS THIS
EVENING...BUT THE HRRR SEEMS TO DECREASE THE COVERAGE AS IT CROSSES
THE STATELINE. THIS SEEMS REASONABLE AS MID LEVEL MOIST LAYER BECOMES
SHALLOWER THE FURTHER WEST IT GETS. CONVECTION LOOKS TO GO TO SLEEP
EARLY THIS EVENING...BUT DID DECIDE TO LEAVE SOME SLIGHT POPS IN FOR
THE SOUTH AND EAST AS THAT IS WHERE IT WILL REMAIN THE LONGEST.
SATURDAY AND FOR THE MOST PART SUNDAY LOOKS DRY ACROSS THE AREA AS
LOW/MID LEVEL EAST/NORTHEAST FLOW WILL CUT OFF THE GULF AND ALLOW
SOME UPPER 50/LOWER 60 SURFACE DEWPOINTS TO WEDGE IN FROM AL/GA.
MID/UPPER LEVEL RIDGING WILL ALSO ADD A WEAK SUBSIDENT COMPONENT TO
THE VERTICAL MOTION AS WELL.
MID/UPPER LEVEL WAVE DIGGING OUT OF THE UPPER MS VALLEY
SATURDAY/SATURDAY NIGHT LOOKS TO PHASE WITH WEAKENING SHORTWAVE
ALONG THE EAST COAST. AS THIS WAVE SWINGS BY TO OUR NORTH AND
EAST...ITS ASSOCIATED COLD FRONT WILL MOVE INTO NORTHERN MS BY LATE
SUNDAY AFTERNOON AND PUSH SOUTHWARD OVERNIGHT. AS COLD FRONT ARRIVAL
TIME WILL BE LATE IN THE DIURNAL CYCLE...DO NOT EXPECT MUCH ACTIVE
CONVECTION SUNDAY...HOWEVER...POOLING MOISTURE AND THE FRONTAL LIFT
SHOULD BE SUFFICIENT FOR ISOLATED STORMS ALONG THE BOUNDARY DURING
THE OVERNIGHT AS IT PUSHES SOUTH./26/
.LONG TERM...MONDAY THROUGH THURSDAY...OVERALL...THE LONG TERM CAN
BE SUMMARIZED A NICE DOWNWARD TREND TO NORMAL TO SLIGHTLY BELOW
NORMAL READINGS THROUGH THE NEXT WEEK AS REINFORCING COOL AIR
INTRUSIONS OCCUR OVER THE ARKLAMISS.
ALL LONG RANGE MODELS ARE IN AGREEMENT OF FRONTAL PASSAGE THROUGH
REGION BY MONDAY AFTERNOON WITH LIMITED PRECIPITATION BUT THE EC IS
SLIGHTLY SLOWER POSSIBLY ALLOWING FOR INSTABILITY INDUCED SHOWERS
ALONG THE FAR SOUTH. YET, FEEL MOST OF REGION WILL BE DRY MONDAY AS
DRIER AND COOLER AIR MOVES IN WITH CLOUDS CLEARING THROUGH THE DAY.
UPPER 40S TO LOWER 50S DEWPOINTS WILL SETTLE OVER REGION TUESDAY
MORNING WITH SLIGHT UPWARD MODIFICATION TO END OF WEEK ALLOWING FOR
COMFORTABLE LOWS AT LEAST INTO THE UPPER 50S WITH SOME MID 50S
POSSIBLE. WOULD BE MORE CONFIDENT IN MID TO LOW 50S IN THIS SET UP
BUT DECENT PRESSURE GRADIENT KEEPING WINDS UP OVERNIGHT COULD ALLOW
FOR SOME MIXING AND KEEP TEMPERATURES FROM DROPPING TO FULL LOW
POTENTIAL. HIGHS WILL LOOK TO TOP OUT IN THE MID TO UPPER 80S WITH
GOOD AMOUNT OF SUN AS A NICE REX BLOCK TO OUR EAST ALLOWS FOR
CONTINUAL LOW-LEVEL EAST/NE COOL AIR FETCH. /ALLEN/
&&
.AVIATION...WITH ISOLATED SHOWERS (AND A FEW HEAVIER DOWNPOURS) THIS
AFTERNOON STRAY AND BRIEF SUB-VFR CATS CANNOT BE RULED OUT GOING
INTO EARLY THIS EVENING. OTHERWISE...LATE TONIGHT INTO EARLY
SATURDAY MORNING EXPECT AT LEAST PATCHY MVFR VIS REDUCTIONS DUE TO
LIGHT FOG.
SURFACE WINDS WILL PRIMARILY BE FROM THE EAST AND SOUTHEAST AND
LIGHT WITH DRY CONDITIONS ANTICIPATED TOMORROW. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 66 90 65 91 / 6 2 3 13
MERIDIAN 64 88 63 90 / 15 1 3 12
VICKSBURG 64 91 63 91 / 4 2 3 14
HATTIESBURG 67 91 67 91 / 17 3 2 12
NATCHEZ 67 89 66 90 / 16 5 3 11
GREENVILLE 67 91 67 92 / 3 4 6 17
GREENWOOD 66 90 65 91 / 3 4 5 17
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
308 PM MDT FRI SEP 19 2014
.SYNOPSIS...
SHOWERS AND PERHAPS A THUNDERSTORM WILL CONTINUE THIS EVENING AND
OVERNIGHT ACROSS PORTIONS OF THE EASTERN PLAINS. THOUGH THE
DAYTIME HOURS ON SATURDAY SHOULD BE MOSTLY QUIET...AS MOISTURE
MOVES BACK INTO THE AREA FROM THE SOUTH AND EAST...SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED TO RAMP BACK UP AGAIN SATURDAY
NIGHT AND SUNDAY. DRIER AIR WILL MOVE INTO THE STATE FROM WEST TO
EAST MONDAY AND TUESDAY. MEANWHILE...TEMPERATURES WILL REMAIN
GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW NORMAL ACROSS THE
EAST. BY THE MIDDLE OF NEXT WEEK...STORM COVERAGE WILL BE
DWINDLING...AND TEMPERATURES WILL REBOUND WITHIN A FEW DEGREES OF
NORMAL AREAWIDE.
&&
.DISCUSSION...
RADAR AND OBSERVATIONS CONTINUE TO SHOW THAT MODELS ARE STRUGGLING
WITH QPF PLACEMENT AND AMOUNTS WITH THE REMNANTS OF ODILE. THIS IS
MAINLY BECAUSE ODILE CONTINUES TO STAY SOUTH OF PROJECTED TRACKS.
INTERESTINGLY...MOST OPERATIONAL MODELS CONTINUE TO SHOW QPF BULLS-
EYES OVER PORTIONS OF THE EASTERN PLAINS THRU THE OVERNIGHT...BUT
THE LATEST HRRR HAS TAKEN THE OPPOSITE TUNE...WITH ALMOST NO PRECIP
PREDICTED. EXPECT REALITY TO BE CLOSER TO THE DRIER
SCENARIO...THOUGH SOME SHOWERS SHOULD PERCOLATE OVERNIGHT ACROSS THE
PLAINS...MUCH LIKE WHAT IS OCCURRING NOW. HAVE ALSO LEFT IN ISOLATED
THUNDER...BUT NOT CONFIDENT MUCH OF THAT WILL HAPPEN.
AS ODILE CONTINUES TO SHIFT EASTWARD AND LOSE ITS IDENTITY...ITS
POOL OF MOISTURE WILL REMAIN OVER WEST TEXAS ON SATURDAY.
MEANWHILE...THE NEXT UPPER LOW WILL TAKE SHAPE OFF THE COAST OF
CALI...AND A WEAK UPPER HIGH WILL BEGIN TO BUILD OVER NM. AS A
RESULT...LOW TO MID LEVEL FLOW WILL BECOME EASTERLY. THOUGH THE
DAYTIME HOURS SHOULD BE RELATIVELY QUIET IN TERMS OF CONVECTION...AS
THE POOL OF MOISTURE IS ADVECTED WESTWARD INTO THE PLAINS...UPSLOPE
FLOW SHOULD ALLOW FOR SHOWERS AND PERHAPS SOME THUNDERSTORMS TO
DEVELOP LATE IN THE AFTN AND EVENING. SHOULD ALSO SEE AN EAST CANYON
WIND PICK UP IN THE RIO GRANDE VALLEY WITH BREEZY TO WINDY
CONDITIONS EXPECTED.
SUNDAY CONTINUES TO TREND TOWARD MORE WIDESPREAD PRECIPITATION AS
THE UPPER LOW EJECTS NEWD OVER THE GREAT BASIN AND LOW/MID LEVEL
MOISTURE CONTINUES TO BE ADVECTED INTO NM FROM THE S AND SE.
INCREASED POPS AREAWIDE...THOUGH GENERALLY STAY A BIT CONSERVATIVE.
WESTERLY FLOW WILL RETURN ON MONDAY...GENERALLY AT THE BASE OF THE
TROUGH/LOW MOVING ACROSS THE CENTRAL/NORTHERN ROCKIES. DRIER AIR WILL
START TO MOVE INTO THE NW BUT STILL A FAIR AMOUNT OF SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED ELSEWHERE. THE TROUGH AXIS WILL
PASS MONDAY NIGHT...AND FLOW WILL BECOME MORE NORTHWESTERLY. THIS
SHOULD TEMPORARILY HALT ANY MONSOONAL MOISTURE FROM MOVING NORTHWARD.
A WEAK UPPER HIGH WILL DEVELOP OVER NM FOR THE MIDDLE TO LATTER HALF
OF THE WORK WEEK...THOUGH ENOUGH MOISTURE SHOULD BE AROUND TO
SUPPORT A FEW STORMS. THE 12Z GFS AND LAST NIGHTS ECMWF BOTH SHOW A
LARGE TROUGH MOVING INTO THE WESTERN US NEXT FRIDAY THRU THE
WEEKEND. THIS SCENARIO WOULD BRING UP ANOTHER BOUT OF MONSOONAL
MOISTURE FOR NM NEXT WEEKEND. HOWEVER...THE 12Z ECMWF DOES NOT SHOW
THE TROUGH AS FAR SOUTH...THUS NOT AS MUCH MOISTURE ADVECTION
NORTHWARD. STAY TUNED.
34
&&
.FIRE WEATHER...
REMNANTS OF ODILE WILL KEEP HIGH HUMIDITY AND SCATTERED SHOWERS
WITH WETTING RAIN REST OF THE AFTERNOON INTO TONIGHT FOR AREAS EAST
OF THE CENTRAL MOUNTAIN CHAIN. EASTERLY FLOW WILL RETURN ACROSS
THE EASTERN PLAINS SATURDAY INCREASING LOW LEVEL RH ACROSS THE
NORTHEAST HALF. DRYING VIA A MID LEVEL DRY INTRUSION EXPECTED
ELSEWHERE...ESPECIALLY WESTERN AREAS. THE BEST CHANCE OF WETTING
RAIN WOULD BE FOUND ACROSS THE SOUTHEAST. GAP WIND GUSTS RANGING
FROM 30 TO 45 MPH WILL BE EXPECTED ALONG THE RIO GRANDE VALLEY
SATURDAY EVENING INTO EARLY SUNDAY MORNING.
RESIDUAL MOISTURE AND A MODERATELY STRONG UPPER LEVEL LOW TO OUR
WEST WILL ENHANCE WETTING RAIN POTENTIAL AREAWIDE FOR SUNDAY.
GREATEST EMPHASIS ACROSS SOUTH CENTRAL AND SOUTHEAST AREAS.
TEMPERATURES WILL COOL 5 TO 10 DEGREES AREA WIDE BUT REMAIN NEAR
NORMAL ACROSS THE NORTHWESTERN HALF OF THE STATE. EASTERLY WINDS
WILL CONTINUE TO BE BREEZY. VENTILATION RATES LOOK TO BE
FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40 CORRIDOR.
MONDAY WILL STILL SEE WETTING RAIN CHANCES AND BELOW NORMAL
TEMPERATURES IN THE EAST...LESS WETTING RAIN POTENTIAL WITH NEAR
NORMAL TEMPERATURES TO THE WEST. VENTILATION NOT EXPECTED TO CHANGE
A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS ALONG AND NORTH
OF I40.
MODELS REMAIN CONSISTENT WITH DEVELOPING A DRYING TREND OVER THE
AREA STARTING TUESDAY ALTHOUGH A WEAK FRONTAL BOUNDARY IS STILL
ANTICIPATED MID WEEK AND FAVOR THE EAST SLOPES OF THE CENTRAL MTNS
EASTWARD. VENTILATION IS EXPECTED TO LOWER SOME TUESDAY/WEDNESDAY
BUT NOT FALL OUT OF SIGHT. MODELS COULD IMPROVE THE NUMBERS AS WE
GET CLOSER TO THAT PERIOD.
THE NEXT UPPER TROUGH STILL ON TAP FOR LATE WEEK INTO THE FOLLOWING
WEEKEND. MODELS REMAIN A LITTLE DIFFERENT IN TERMS OF TIMING AND
STRENGTH OF IMPACTS. THE GFS IS MUCH DEEPER AND MORE PROGRESSIVE
WITH THE TROUGH THUS SOME WIND IMPACTS POSSIBLE AHEAD OF IT. THIS
IMPACTS VENTILATION RATES. ECMWF IS A BIT SLOWER. LOWER CONFIDENCE
PERIOD FOR LATE WEEK INTO NEXT WEEK AT THIS TIME.
32/50
&&
.AVIATION...
18Z TAF CYCLE
SH AND VCSH WITH MVFR CONDITIONS FROM REMNANTS OF ODILE WILL
IMPACT TERMINAL SITES ACROSS THE EASTERN PLAINS THROUGH THIS
EVENING...WITH GREATER IFR CONFIDENCE FOR TCC. AREAS OF PATCHY FOG
AND LOW CLOUDS WILL ALSO IMPACT SITES EAST OF THE CENTRAL MTN
CHAIN. WINDS WILL SHIFT EASTERLY OVERNIGHT INTO
SATURDAY SO THERE IS A CHANCE OF MVFR CIGS IMPACTING CENTRAL
TERMINAL SITES SUCH AS ABQ/SAF. BEST CHANCE OF LOW CIGS IMPACTING
CENTRAL LOCATIONS WOULD BE SAF AND USED SCT025 TO INDICATE THAT
AFTER 8Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 54 88 60 83 / 5 5 20 30
DULCE........................... 45 86 49 80 / 10 10 20 40
CUBA............................ 50 84 51 78 / 10 10 20 40
GALLUP.......................... 46 84 51 80 / 10 10 20 40
EL MORRO........................ 48 78 50 75 / 10 10 20 40
GRANTS.......................... 49 82 54 77 / 10 10 20 40
QUEMADO......................... 51 78 53 74 / 10 20 20 50
GLENWOOD........................ 54 83 52 82 / 20 30 30 30
CHAMA........................... 40 80 44 74 / 10 10 20 40
LOS ALAMOS...................... 55 81 56 74 / 20 10 20 40
PECOS........................... 50 77 53 69 / 20 10 30 50
CERRO/QUESTA.................... 46 78 48 75 / 10 10 20 40
RED RIVER....................... 40 71 43 67 / 10 20 30 50
ANGEL FIRE...................... 37 75 38 69 / 10 10 30 50
TAOS............................ 48 81 50 74 / 10 10 20 30
MORA............................ 48 76 50 67 / 20 10 30 50
ESPANOLA........................ 56 87 55 80 / 10 10 20 30
SANTA FE........................ 53 80 56 75 / 20 10 20 40
SANTA FE AIRPORT................ 54 84 56 77 / 20 10 20 30
ALBUQUERQUE FOOTHILLS........... 59 84 61 79 / 20 10 20 40
ALBUQUERQUE HEIGHTS............. 62 85 63 80 / 20 10 20 30
ALBUQUERQUE VALLEY.............. 60 86 60 82 / 20 10 20 30
ALBUQUERQUE WEST MESA........... 61 85 61 81 / 10 10 20 30
LOS LUNAS....................... 57 86 58 82 / 10 10 20 30
RIO RANCHO...................... 60 88 61 82 / 10 10 20 30
SOCORRO......................... 61 86 62 83 / 20 10 30 40
SANDIA PARK/CEDAR CREST......... 56 80 57 78 / 20 10 20 40
TIJERAS......................... 55 82 58 78 / 20 10 30 40
MORIARTY/ESTANCIA............... 47 80 49 74 / 20 10 30 50
CLINES CORNERS.................. 55 76 54 70 / 20 10 40 60
GRAN QUIVIRA.................... 57 77 57 70 / 20 20 40 50
CARRIZOZO....................... 60 80 60 73 / 30 20 40 50
RUIDOSO......................... 55 73 53 70 / 40 20 50 60
CAPULIN......................... 53 77 53 71 / 20 10 20 30
RATON........................... 55 82 51 76 / 10 10 20 40
SPRINGER........................ 53 83 53 76 / 20 10 30 40
LAS VEGAS....................... 51 78 51 71 / 20 10 40 50
CLAYTON......................... 60 81 58 78 / 20 20 20 30
ROY............................. 57 79 56 74 / 30 10 30 40
CONCHAS......................... 63 80 62 78 / 30 20 40 40
SANTA ROSA...................... 63 79 61 74 / 30 20 50 50
TUCUMCARI....................... 63 82 63 80 / 50 30 30 40
CLOVIS.......................... 63 76 62 76 / 60 40 40 50
PORTALES........................ 63 76 62 77 / 70 40 40 50
FORT SUMNER..................... 64 79 62 74 / 40 30 50 50
ROSWELL......................... 66 79 65 78 / 50 20 50 60
PICACHO......................... 60 76 60 70 / 40 20 50 60
ELK............................. 58 73 57 67 / 40 20 50 60
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34
AREA FORECAST DISCUSSION
NWS BISMARCK ND
230 PM CDT FRI SEP 19 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 230 PM CDT FRI SEP 19 2014
SCATTERED THUNDERSTORMS NORTH THIS AFTERNOON AND EVENING...AND WINDY
CONDITIONS WITH RAIN SHOWERS SATURDAY HIGHLIGHT THE SHORT TERM FORECAST.
THE 12 UTC GLOBAL SUITE AND THE 14-15 UTC HRRR ITERATIONS CONTINUE
TO SUGGEST SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON
THROUGH SUNSET ALONG AND NORTH OF THE US HIGHWAY 2
CORRIDOR...BEHIND A WEAK SECONDARY COLD FRONT WITH 50S SURFACE DEWPOINTS
IN TRAIL. SEVERE CONVECTION IS NOT ANTICIPATED AND WILL FADE
QUICKLY WITH SUNSET.
FOR SATURDAY...THE SHORTWAVE CURRENTLY ACROSS WESTERN ALBERTA
THIS AFTERNOON IS FORECAST TO PROPAGATE ACROSS NORTH DAKOTA DURING
THE MORNING AND EARLY AFTERNOON. THE HIGHEST POPS ARE FOCUSED
ACROSS THE NORTH CENTRAL AND EAST...WITH THE SOUTHWEST FORECAST TO
BE PRECIPITATION FREE. DID INCLUDE AN ISOLATED THUNDER MENTION
WITH WEAK INSTABILITY. SATURDAY WILL BE WINDY WITH A TIGHT
PRESSURE GRADIENT BETWEEN THE SURFACE HIGH IN MONTANA AND LOW
PRESSURE OVER LAKE WINNIPEG. THE 12 UTC NAM/GFS BUFR SOUNDINGS
DEPICT 30-35 KTS OF FLOW AT THE TOP OF THE MIXED LAYER...WHICH
EQUATES TO BRISK NORTHWEST WINDS THAT REMAIN BELOW ADVISORY
CRITERIA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 230 PM CDT FRI SEP 19 2014
THE LONG TERM BEGINS WITH THE WESTERN RIDGE OVER THE ROCKIES AND A
CUTOFF LOW OVER CALIFORNIA/NEVADA...WITH NORTHWEST FLOW ALOFT OVER
THE DAKOTAS. THE UPPER RIDGE MOVES EAST INTO THE PLAINS THROUGH THE
WEEKEND...WITH THE CUTOFF LOW LIFTING NORTHEASTWARD SLOWLY
COINCIDENT WITH THE UPPER RIDGE`S EASTWARD MOVEMENT. DURING THIS
TIME...SURFACE HIGH PRESSURE WILL BRING MILD AND DRY AIR TO WESTERN
AND CENTRAL NORTH DAKOTA. DRY THROUGH MONDAY NIGHT. LOW TEMPERATURES
SUNDAY MORNING FROM THE UPPER 30S WEST TO 40S CENTRAL...WARMING TO
LOWS IN THE 50S BY TUESDAY MORNING. HIGHS SUNDAY UPPER 60S TO LOWER
70S...AND IN THE 70S ON MONDAY.
BY TUESDAY THE MEANDERING CUTOFF UPPER LEVEL LOW IS FORECAST TO BE
OVER THE NORTHERN/CENTRAL PLAINS...BRINGING A CHANCE OF SHOWERS OR
THUNDERSTORMS TO THE FORECAST AREA TUESDAY AND WEDNESDAY. MEANWHILE
A LONGWAVE TROUGH DEVELOPS OVER THE WEST COAST...AND UPSTREAM
RIDGING OCCURS OVER THE PLAINS AHEAD OF THIS SYSTEM...LEADING TO A
DRY END OF THE WEEK. CONTINUED MILD WITH LOWS IN THE 50S...AND HIGHS
IN THE 70S TO AROUND 80.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 230 PM CDT FRI SEP 19 2014
A WEAK COLD FRONT WAS ENTERING NORTHWEST NORTH DAKOTA THIS
AFTERNOON...MOVING SOUTHEAST INTO THE EARLY EVENING. SCATTERED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE BEHIND THE
FRONT...POTENTIALLY IMPACTING KMOT AND KISN. WESTERLY WIND GUSTS
OF 25-30 KTS ARE EXPECTED ACROSS MUCH OF THE AREA THROUGH SUNSET.
ANOTHER ROUND OF SHOWERS IS POSSIBLE ACROSS NORTHERN AND CENTRAL
NORTH DAKOTA SATURDAY...WITH STRONG NORTHWEST WINDS OF 30 TO 35
KTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AYD
LONG TERM...JV
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1256 PM CDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 1255 PM CDT FRI SEP 19 2014
NO SIGNIFICANT CHANGES FROM THE PREVIOUS UPDATE. THE SECONDARY
COLD FRONT IS JUST ENTERING NORTHWEST NORTH DAKOTA AS OF 18 UTC.
RELATIVELY ELEVATED DEW POINTS IN THE MID 50S BEHIND THIS BOUNDARY
WILL BE THE FOCUS FOR DIURNAL SCATTERED SHOWERS AND THUNDERSTORMS
ALONG AND NORTH OF US HIGHWAY 2. NO SEVERE WEATHER IS EXPECTED.
UPDATE ISSUED AT 855 AM CDT FRI SEP 19 2014
AS OF 1330 UTC...THE SURFACE COLD FRONT WAS LOCATED FROM NEAR
CAVALIER IN NORTHEAST NORTH DAKOTA THROUGH SELFRIDGE IN THE SOUTH
CENTRAL. SCATTERED RAIN SHOWERS WITH ISOLATED THUNDERSTORM
ACTIVITY WILL CONTINUE ALONG THIS FRONT WITH SURFACE DEWPOINTS IN
THE LOWER 60S. THIS FRONT WILL EXIT INTO THE RED RIVER VALLEY BY
MID DAY. THEREAFTER...DRIER AIR AND WELL MIXED CONDITIONS
OVERTAKE MUCH OF THE AREA BEHIND THIS FRONT. A SECONDARY COLD
FRONT/SURFACE TROUGH ACROSS SOUTHERN SASKATCHEWAN THIS MORNING
WILL PROPAGATE INTO THE US HIGHWAY 2 CORRIDOR THIS
AFTERNOON...AND WILL BE THE FOCUS FOR ADDITIONAL THUNDERSTORM
DEVELOPMENT.
UPDATE ISSUED AT 626 AM CDT FRI SEP 19 2014
SHOWERS WITH A FEW THUNDERSTORMS CONTINUE TO MOVE THROUGH PORTIONS
OF SOUTHERN NORTH DAKOTA...AND ANOTHER AREA STARTING TO DEVELOP
OVER NORTH-CENTRAL NORTH DAKOTA. THIS FALLS WELL IN LINE WITH
LATEST HRRR OUTPUT. MORNING UPDATE WILL ADDRESS THESE AREAS AND
REMOVE POPS OVER THE FAR WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI SEP 19 2014
THIS MORNING A COLD FRONT WAS MOVING THROUGH WESTERN/CENTRAL NORTH
DAKOTA. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE
PRIMARILY FOCUSED ALONG THE FRONT AND PARALLEL/ON THE SOUTH SIDE
OF AN H300 JET. TO THE NORTH ISOLATED SHOWERS WERE ACROSS
SOUTHERN SASKATCHEWAN ASSOCIATED WITH THE SHORTWAVE TROUGH AT
H500. FOLLOWED THE HRRR AND NAM FOR POP GUIDANCE THIS MORNING.
BEST CHANCE FOR PRECIP WILL REMAIN ALONG THE SOUTH DAKOTA
BORDER...MAINLY SOUTH CENTRAL THIS AM. PRECIP ACROSS THE SOUTH
WILL GRADUALLY DIMINISH THIS MORNING AS SUBSIDENCE BEHIND THE
FRONT AND H300 JET TAKES HOLD. THEN THE EXIT REGION OF AN UPSTREAM
H300 JET WILL POSITION ITSELF TO SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS ALONG THE NORTHERN BORDER THIS AFTERNOON. IT WILL BE
A LITTLE E BREEZY WEST AFTER THIS AFTERNOON IN THE WAKE OF THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI SEP 19 2014
SOME SHOWERS/THUNDERSTORMS MAY LINGER INTO SATURDAY PRIMARILY OVER
NORTHERN INTO CENTRAL/EASTERN NORTH DAKOTA AS AREA REMAINS UNDER
CYCLONIC FLOW AND A POTENT SHORT WAVE MOVES THROUGH THE AREA. GUSTY
WINDS ARE EXPECTED TO DEVELOP THROUGHOUT THE AREA AS THE WAVE DIVES
THROUGH AND STRONGER WINDS MIX DOWN. WINDS WILL TAPER BY EVENING
WITH PRECIP ENDING AS UPPER RIDGE BUILDS OVER THE ROCKIES. QUIET
WEATHER EXPECTED TO START THE WEEK AS RIDGE AXIS WORKS EAST. BY
TUESDAY...A COMPACT UPPER LOW WORKS THROUGH THE RIDGE AND APPROACHES
THE REGION...SLOWLY WORKING OVER THE AREA THROUGH MID-WEEK. MODELS
STILL STRUGGLING SOME ON THE PLACEMENT OF THIS SYSTEM THOUGH AT THIS
TIME IT APPEARS THAT MOST OF THE PRECIP SHOULD STAY SOUTH OF THE
AREA SO WILL KEEP POPS ON THE LOW SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1255 PM CDT FRI SEP 19 2014
THE FIRST OF TWO COLD FRONTS HAS ENTERED INTO THE RED RIVER
VALLEY...WITH A SECOND...WEAKER FRONT ENTERING THE
NORTHWEST...MOVING SOUTHEAST INTO THE EARLY EVENING. SCATTERED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE BEHIND THE
FRONT...POTENTIALLY IMPACTING KMOT AND KISN. WESTERLY WIND GUSTS
OF 25-30 KTS ARE EXPECTED ACROSS MUCH OF THE AREA THROUGH SUNSET.
ANOTHER ROUND OF SHOWERS IS POSSIBLE ACROSS NORTHERN AND CENTRAL
NORTH DAKOTA SATURDAY...WITH STRONG NORTHWEST WINDS OF 30 TO 35
KTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1253 PM CDT Fri Sep 19 2014
.AVIATION...
/18Z TAFS/
The main aviation forecast concerns are with showers/thunderstorms
and associated reductions in ceilings and visibilities this
afternoon into tonight, and with possible IFR/LIFR conditions
late tonight and early Saturday morning, with low cloud ceilings.
Area of showers persists early this afternoon from north of Brady
to around Sweetwater. New band of convection has developed from
just southeast of Brady, south across eastern Mason County. Other
showers developing west and southwest of San Angelo. All of this
convective activity is moving very slowly north-northeast. Expect
an increase in coverage of showers with scattered thunderstorms
this afternoon and evening. Carrying VCSH/VCTS groups in the area
TAFs, and will update as needed. Additional showers and
thunderstorms are expected tonight, with the best chance across
our western and northwestern counties. The models were on target
with the extent of low cloud development that occurred early this
morning. Outside of convective activity, anticipate that this will
occur again late tonight and early Saturday morning. Carrying low
cloud (IFR) ceilings at the TAF sites.
19
&&
.PREV DISCUSSION... /ISSUED 1003 AM CDT FRI SEP 19 2014/
UPDATE...
A forecast update is in order this morning. Satellite imagery
shows widespread cloud cover, and surface observations have
indicated widespread IFR and LIFR ceilings. Radar imagery shows a
band of rain showers with moderate to occasionally heavy rain,
extending from Eden northwest into southwestern Nolan County. Area
of moderate to heavy rain over West Texas is slowly shifting east or
east-southeast (referenced in the Satellite Precipitation Estimates
product from NESDIS). Will update the forecast, at this time to
increase cloud cover and re-work the PoP field for today.
19
PREV DISCUSSION... /ISSUED 637 AM CDT FRI SEP 19 2014/
AVIATION...
/12Z TAFS/
Ceilings have come down in many places to less than 2000 ft, but
trying to pin down a prevailing height is akin to playing
whack-a-mole with Mother Nature. In general, ceilings will bounce
around between IFR and MVFR, briefly dropping to less than 500 ft
at times over the next few hours. Visibilities have followed suit
along the I-20 corridor, ranging from 1/4 to 3 miles in the past
hour. Generally improving conditions are anticipated by mid/late
morning, with prevailing VFR conditions anticipated after 16z.
Current convection is expected to weaken this morning, but
additional development is expected this afternoon and tonight. A
VCSH group was appended to all sites excluding KABI this
afternoon. Any cells that develop may produce brief IFR
visibilities and/or MVFR ceilings. Rain chances increase tonight
across the north. Expect a general easterly wind at 10 kts or
less.
Johnson
PREV DISCUSSION... /ISSUED 345 AM CDT FRI SEP 19 2014/
SHORT TERM...
(Today and tonight)
A split flow pattern persists over the western CONUS with a
relatively deep trough along the West Coast, cut off from the
stronger westerlies over the northern tier. The mid/upper-level
ridge remains in place over the southern Rockies and Plains, but
the remnants of Odile are trapped beneath this ridge, moving
very slowly to the east across NM this morning. Copious tropical
moisture has been advected into the region, as evidenced by the
precipitable water values from the 00z raobs. Both the FWD and DRT
precipitable water values are just below two standard deviations
above climatology. However, the 1.95" PWAT at KMAF is above the
99th percentile. In other words, pretty rare! GPS PWAT data
indicates values over 2.00" east of DRT. Southerly 850mb winds of
15-20 kts will continue to advect this moisture poleward
throughout the day.
Analysis of the wind field hints at a very weak surface boundary
(or trough) extending from northwest to southeast across the
CWA. The RAP Mesoanalysis also indicates a bit of a theta-e
gradient over the southwest zones, in the vicinity of the stronger
convection earlier in the evening. The convection over our neck of
the woods continues to weaken this morning, as does the
precipitation moving into the Permian Basin. However, we should
still see at some activity around through the morning hours.
Despite the abundant cloud cover, temperatures are forecast to
warm into the mid/upper 80s across the southern and eastern zones,
which should promote the development of additional convection by
midday. Most of the models favor the southwest half of the
forecast area for the development of showers and thunderstorms
today, likely focusing a bit farther north, primarily over the
western Big Country and Concho Valley tonight.
The hi-res CAMS are suggesting that convection during the daytime
period will be more cellular in nature, keeping the threat for
flash flooding on the low side. However, tonight, as the low-
level jet begins to intensify, we may see this activity grow
upscale. Given the lower flash flood threat for today, no Flash
Flood Watch will be issued at this time. That said, a watch may be
warranted next shift, focused on the overnight period.
LONG TERM...
(Saturday into Thursday)
Potential for heavy rainfall and flooding will continue this
weekend. Remnants of Odile are expected to push northeast into the
Panhandle and Northwest Texas early Saturday. A cold front then
moves through West Central Texas, from northeast to southwest,
Saturday afternoon and night, acting as a continuing focus for
heavy rainfall.
Both the GFS and NAM models indicate heavy rainfall amounts of 1
to 3 inches in the Big Country and Concho Valley, Saturday and
Saturday night. Locally heavier amounts possible as the tropical
atmosphere will be a efficient rainfall producer. Sunday afternoon,
the heavy rainfall focus moves to the Concho Valley and areas
southwest including Crockett county. This occurs, as more stable air
moves in from the northeast. The main potential for heavy rainfall
then moves southwest of the region Sunday night, with Crockett
county having the best chance of rain. Flash flood watches may be
needed this weekend. Of course, rainfall and runoff will be
extremely beneficial as reservoirs are at extremely low levels and
much West Central Texas is in moderate to extreme drought.
Kept a slight chance of showers on Monday with low/mid level
moisture remaining. Rainfall amounts will be light, if the occur.
A more stable atmosphere remains over the region the rest of the
week, as weak surface high pressure builds in.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 84 69 83 70 85 / 80 50 60 50 30
San Angelo 84 70 86 70 86 / 60 50 60 50 40
Junction 87 72 86 72 87 / 50 30 40 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
216 PM EDT FRI SEP 19 2014
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL SHIFT WEST ACROSS THE MOUNTAINS
TODAY AHEAD OF STRONG HIGH PRESSURE BUILDING IN FROM THE NORTH BY
THIS AFTERNOON. THE HIGH WILL WEDGE SOUTH ALONG THE EASTERN
SLOPES OF THE APPALACHIANS TONIGHT INTO SUNDAY KEEPING DRY
WEATHER IN PLACE. A COLD FRONT SHOULD CROSS THE AREA FROM THE
NORTHWEST LATER SUNDAY NIGHT INTO MONDAY FOLLOWED BY COOLER AND
DRIER WEATHER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1139 AM EDT FRIDAY...
MADE SOME QUICK ADJUSTMENTS IN POPS TO EXPAND COVERAGE OF LIGHT
POPS FURTHER NORTH OF HIGHWAY 460 FOR THIS AFTERNOON. ALSO
ADJUSTED TEMPERATURES AND DEW POINTS FOR THIS AFTERNOON INTO
TONIGHT. CUT BACK ON MENTION OF THUNDERSTORMS FOR THIS AFTERNOON.
AS OF 933 AM EDT FRIDAY...
THIS MORNINGS 12Z RNK SOUNDING DISPLAYED PLENTY OF LOW LEVEL
MOISTURE TRAPPED BELOW THE SUBSIDENCE INVERSION WITH A EASTERLY FLOW
FROM SFC UP TO 1KFT. KFCX 88D IMAGES HIGHLIGHTED A FEW SHOWERS THIS
MORNING ESPECIALLY ALONG THE FOOTHILLS OF THE BLUE RIDGE MOUNTAINS.
THIS ACTIVITY IS BEING SUPPORTED BY THE COMBINATION OF A WEAK
SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL THETA-E RIDGING
EAST OF THE BLUE RIDGE. A BLEND OF THE HRRR AND HI RESW-ARW CAPTURED
THIS MORNING POPS.
TWO CHALLENGES FOR THIS AFTERNOON FORECAST ARE HOW FAST/DEEP CAD IS
AND WHATS THE WESTERN EXTENT OF CLOUD COVER. MODEL GUIDANCE STILL
SHOWS AN AXIS OF INSTABILITY ALONG THE I-77 CORRIDOR THIS AFTERNOON
WITH THE WESTERN MOVING SURFACE TROUGH. INCLUDED AN ISOLATED TSRA
MENTION IN NORTHWEST NORTH CAROLINA RIDGES/FOOTHILLS THIS
AFTERNOON WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
TEMPERATURES WILL LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW
DECK AND EASTERLY FLOW. HOWEVER THE FAR WEST COULD ACTUALLY SEE
READINGS PUSH INTO THE 70S GIVEN THE SLOWER WEDGING.
MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES...POPS AND CLOUD COVER
FOR THIS MORNING INTO THIS AFTERNOON.
AS OF 230 AM EDT FRIDAY...
COMBINATION OF A WEAK SURFACE TROUGH ACROSS THE PIEDMONT AND LOW LEVEL
THETA-E RIDGING EAST OF THE BLUE RIDGE CONTINUES TO LEAD TO ISOLATED
SLOW MOVING SHOWERS IN SPOTS EARLY THIS MORNING. EXPECT THIS TO PERSIST
A WHILE LONGER PER LATEST HRRR BEFORE THE DEVELOPING WEDGE STARTS TO
ENHANCE FROM NE TO SW BUT A BIT SLOWER THAN EARLIER THOUGHT. THIS
SHOULD START TO PRODUCE SOME SPOTTY -DZ ALONG THE EASTERN SLOPES AS
SHOWERS WANE PER INCREASING STABILITY BUT LOOKS LESS THAN PREVIOUS
GIVEN DRY AIR SAGGING IN FROM THE NORTH OFF MSAS. HOW FAST/DEEP ANY OF
THE LOW CLOUDS CAN BANK IN ALONG THE EASTERN SLOPES KEY TO CLOUDS/TEMPS
THIS AFTERNOON WITH MODELS NOW SLOWER IN INITIALLY PUSHING THE CAD
SOUTH AND WEST. THIS MAY LEAD TO AN AXIS OF MODEST INSTABILITY ESPCLY
ALONG THE I-77 CORRIDOR EARLY THIS AFTERNOON WHERE GUIDANCE REDEVELOPS
SHRA ALONG THE WESTWARD MOVING SURFACE TROUGH. SINCE THIS IN LINE WITH
CONSENSUS...BUMPED UP CHANCE POPS ACROSS NW NC...AND SW VA LATER WHILE
TRIMMING ANY -DZ/-RA TO ISOLATED -SHRA BLUE RIDGE...AND LITTLE MORE
THAN CLOUDS EAST-NE AS BUILDING HIGH PRESSURE START TO ENHANCE INLAND
FROM THE MID ATLANTIC COAST. ALSO INCLUDED AN ISOLATED -TSRA MENTION NW
NC RIDGES/FOOTHILLS WHERE BEST LOW LEVEL CONVERGENCE LINES UP WITH THE
PASSING TROUGH UNDER DECENT 85H THETA-E RIDGING.
OTRW CLOUD COVER AND TEMPS THE MAIN ISSUES ESPCLY BLUE RIDGE WHERE
LIKELY TO BE STUCK MOSTLY IN THE 60S UNDER LOW DECK AND EASTERLY FLOW.
HOWEVER COULD ACTUALLY SEE READINGS PUSH INTO THE 70S FAR WEST GIVEN
THE SLOWER WEDGING...AS WELL AS OVER THE SOUTH/EAST IF CAN GET MORE
SUNNY BREAKS AS MOISTURE STARTS TO DECREASE FROM THE EAST LATE.
SURFACE RIDGING STRENGTHENS FROM THE NE OVERNIGHT HELPING PUSH THE
RESIDUAL AXIS OF MOISTURE FARTHER WEST WHICH SHOULD BRING AN END TO
POPS DURING THE EVENING. BANKED UP LOW LEVEL MOISTURE THOUGH LIKELY TO
REDEVELOP OR PERSIST BLUE RIDGE WHERE LOTS OF LOW CLOUDS/FOG POSSIBLE.
APPEARS AREAS OVER THE EAST/SE FROM HIGHWAY 29 EAST COULD SEE SOME
CLEARING AS MOISTURE GETS PINCHED FARTHER WEST AHEAD OF THE DRIER
EASTERLY FLOW. OTRW VARYING DEGREE OF CLOUDS FROM THE BLUE RIDGE WEST
WITH LOWS MAINLY IN THE 50S PER LATEST SIMILAR MAV/MET MOS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
THE HIGH PRESSURE CENTER THAT WAS OVER NEW ENGLAND WILL MOVE OUT
INTO THE ATLANTIC OVER THE WEEKEND. HOWEVER...THIS RIDGE WILL REMAIN
WEDGE BACK OVER THE MID ATLANTIC AND SOUTHEASTERN STATES INTO
SATURDAY NIGHT. A GULF STREAM DISTURBANCE WILL HELP KEEP THIS WEDGE
IN THE AREA AND ALSO PROVIDE SUBSIDENCE TO KEEP THE FORECAST AREA
DRY SATURDAY. THESE DISTURBANCE WILL HAVE MOST OF ITS RAIN FALLING
ON ITS EASTERN FLANK AS DRY AIR IS ENTRAINED INTO THE WESTERN SIDE.
THIS DISTURBANCE WILL TRACK TO THE NORTHEAST AND WILL REMAIN
OFFSHORE THROUGH THE WEEKEND.
MODELS HAVE SPED UP THE TIMING OF THE NEXT FRONTAL PASSAGE FROM
MONDAY TO SUNDAY. THIS FRONT STILL LOOKS LIKE A TYPICAL FALL FRONTAL
PASSAGE WITH RAIN FALLING ALONG WESTERN SLOPES...LOSING THEIR
INTENSITY MOVING TO THE BLUE RIDGE. THIS PRECIPITATION MAY THEN JUMP
THE FOOTHILLS AS A WEAK LINE OF CONVECTION DEVELOPS OVER THE
PIEDMONT WHERE A LEE TROUGH WILL RESIDE SUNDAY AFTERNOON. THE NAM
AND ECM LOOK SIMILAR WITH KEEPING BULK OF THE RAIN OVER THE
MOUNTAINS. THE GFS PROGRESSIVELY MOVES THE FRONT AND RAINFALL ACROSS
THE ENTIRE FORECAST AREA...DISREGARDING DOWNSLOPE. THE FORECAST DID
NOT DISCREDIT THE GFS...BUT MORE WEIGHT WAS PLACED WITH THE NAM/ECM
FOR SUNDAY.
SATURDAY TEMPERATURES WILL RUN WARMER THAN NORMAL WITH UPPER 70S TO
LOWER 80S. AREAS NOT SEEING RAIN UNTIL LATER IN THE DAY SUNDAY
SHOULD HAVE TEMPERATURES IN THE LOWER TO MID 80S. WESTERN SLOPES
SHOULD HAVE RAIN FALLING BY THE AFTERNOON AND MAY SEE HIGHS IN THE
MID 70S SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 200 PM EDT THURSDAY...
THIS PERIOD IS SHAPING UP TO BE DRY AND SEASONAL. ANOTHER SHORTWAVE
DROPS SOUTHEAST ACROSS THE TN VALLEY MONDAY AND COULD BRING ISOLATED
SHOWERS TO THE ENTIRE AREAS AS FLOW BACKS ALOFT SOME. THEN HIGH
PRESSURE ACROSS THE MIDWEST PUSHES EAST OVER THE MID ATLANTIC
TUE- WED. TEMPS BEHIND THIS SYSTEM EARLY NEXT WEEK WILL COOL DOWN
SOME...BUT NOT LOOKING AS CHILLY AS EARLIER THOUGHT...WITH 8H
TEMPS +10-12C.
HIGHS WILL RUN FROM THE 60S WEST TO 70S EAST...WITH LOWS MAINLY IN
THE 40S...WITH SOME 50S ACROSS THE PIEDMONT.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 200 PM EDT FRIDAY...
RADAR INDICATES LIGHT RAIN CONTINUING TO DRIFT NORTH THIS
AFTERNOON...THINNING AS IT PROGRESSES...AS IT MOVES INTO THE
INCREASINGLY STABLE AIR ASSOCIATED WITH HIGH PRESSURE WEDGED
AGAINST THE EASTERN FACE OF THE APPALACHIANS. WIND FLOW REMAINS
OUT OF THE NORTH-NORTHWEST EAST OF THE BLUE RIDGE...BECOMING
EASTERLY TO SOUTHEASTERLY ACROSS THE MOUNTAINS. THE UPSLOPE FLOW
IS MAINTAINING IFR CEILINGS FOR LYH/ROA/BCB/LWB...WHILE BLF
REMAINS OUTSIDE THE WEDGE. LOW CEILINGS HAVE MIXED OUT IN THE
SLIGHTLY MORE UNSTABLE AIR NEAR DAN.
LOW CEILINGS WILL LINGER THROUGH THE DAY...WITH ONLY MODEST
IMPROVEMENT...AS DRIER AIR WORKS IN FROM THE NORTHEAST. HOWEVER...
FORECAST MODELS ARE IN GOOD AGREEMENT THAT MVFR/IFR CONDITIONS
WILL REMAIN ACROSS THE AREA THROUGH TONIGHT...WITH LOW CEILINGS
HOLDING ACROSS THE MOUNTAIN AIRPORTS. FURTHER EAST...CLEARING IS
EXPECTED...ONLY FOR PATCHES OF FOG TO DEVELOP SHORTLY BEFORE
SUNRISE AS THE ATMOSPHERE SATURATES. LITTLE CHANGE IN WIND
DIRECTION OR SPEED IS ANTICIPATED.
WITH INCREASINGLY DRIER AIR WORKING IN THROUGH THE NIGHT...MVFR
AND IFR CONDITIONS WILL ERODE QUICKLY AFTER 9 AM SATURDAY ONCE
DAYTIME HEATING INCREASES. DEEPER MOUNTAIN VALLEYS MAY MAINTAIN
FOGGY CONDITIONS FOR AN HOUR OR TWO LONGER. VFR CONDITIONS ARE
EXPECTED THROUGH THE REMAINDER OF THE DAY.
EXTENDED AVIATION DISCUSSION...
WEDGE SHOULD ERODE FAIRLY QUICKLY SATURDAY NIGHT IN RESPONSE TO
AN UPSTREAM TROUGH. SOME LOW CLOUDS MAY LINGER THROUGH THE MORNING
ALONG WITH PATCHY FOG...BUT OVERALL VFR CONDITIONS EXPECTED SAT. A
FRONTAL SYSTEM WILL APPROACH SUN WITH -SHRA AND PERHAPS AN ISOLD
TSRA WEST OF THE ALLEGHANY FRONT. INSTABILITY IS QUITE LIMITED AND
SO IS DEEP MOISTURE. WITH A POSSIBLE TROPICAL SYSTEM DEVELOPING
OFF THE COAST AT THE SAME TIME...WE MAY BE IN A STRONG SUBSIDENCE
AREA AND SEE LITTLE MORE THAN -SHRA OR SPRINKLES EAST OF THE
ALLEGHANY FRONT. EXPECT MOSTLY VFR-PERIODS OF MVFR CIGS SUN-EARLY
MON AS THE TROUGH MOVES THROUGH. HIGH PRESSURE BUILDS IN FOR THE
FIRST HALF OF NEXT WEEK WITH DRY NW FLOW. THUS...EXPECT MOSTLY VFR
CONDITIONS THROUGH THE PERIOD WITH LOCAL EARLY MORNING MVFR-IFR
FOG CONDITIONS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH/KK
SHORT TERM...RCS
LONG TERM...WP
AVIATION...JH/NF
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1244 PM CDT FRI SEP 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 219 AM CDT FRI SEP 19 2014
FORECAST CONCERNS INCLUDE PRECIPITATION CHANCES THROUGH
TONIGHT...SEVERE WEATHER POTENTIAL TONIGHT...AND WINDS THIS
AFTERNOON.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE CENTRAL PLAINS WHILE A FAST SEMI-ZONAL FLOW
WAS PRESENT ALONG THE U.S./CANADIAN BORDER. WITHIN THIS FLOW...A
SHORTWAVE TROUGH WAS OVER SOUTHERN SASKATCHEWAN AND ADJACENT
MONTANA. THIS TROUGH HAS BEEN RESPONSIBLE FOR... 1. PLENTY OF
MID/HIGH CLOUDS DOWNSTREAM OVER THE DAKOTAS...SOME OF WHICH WERE
PRODUCING SHOWERS AND A FEW THUNDERSTORMS. 2. PULLING MORE HUMID AIR
THROUGH THE DAKOTAS ON A 20-40 KT JET AT 925MB WITH SURFACE
DEWPOINTS IN THE 60S...AS WELL AS PRECIPITABLE WATER OF 1-1.5
INCHES. FINALLY 3...DEVELOPING AN UNSEASONABLY WARM...CAPPED AIRMASS
OVER SOUTH DAKOTA CHARACTERIZED BY 850MB TEMPS OF 18-24C AND 700MB
TEMPS OF 10-13C. OVER THE FORECAST AREA...MUCH COOLER AND DRIER AIR
EXISTS WITH 850MB TEMPS AROUND 10C AND PRECIPITABLE WATER AROUND 0.5
INCH. A WARM FRONT SEPARATES THE DIVISION OF AIRMASSES OVER WESTERN
MN...WHICH ISENTROPIC LIFT/MID-LEVEL MOISTURE TRANSPORT INTO THE
FRONT HAS LED TO MID CLOUDS IN MN. NOTHING YET FALLING OUT OF
THESE...THOUGH.
MODELS ARE IN AGREEMENT TRACKING THE SHORTWAVE TROUGH OVER
SASKATCHEWAN AND MONTANA INTO THE DAKOTAS BY 00Z. WHAT THIS DOES IS
HELP CONTINUE A WARM ADVECTION REGIME DOWNSTREAM INTO THE FORECAST
AREA. THE BIG PLUME OF WARM 700MB AND 850MB AIR OVER SOUTH DAKOTA
STREAMS EAST-NORTHEAST ACROSS THE FORECAST AREA...AS WELL AS OVER
CENTRAL MN AND NORTHWEST WI...EFFECTIVELY PUTTING A NICE CAP IN
PLACE. PRIOR TO THIS CAP ARRIVING THIS AFTERNOON...A FEW DAYS AGO IT
APPEARED THAT THE ISENTROPIC LIFT AND MID-LEVEL MOISTURE TRANSPORT
WOULD BE ENOUGH TO INITIATE CONVECTION. HOWEVER...THAT DOES NOT
APPEAR TO BE THE CASE ANYMORE WITH MOST MODELS SUGGESTING A DRY DAY
TODAY. HAVE STILL LEFT SOME LOW CHANCES IN TAYLOR AND CLARK COUNTIES
FOR THE LATE AFTERNOON...DUE TO ACTIVITY OVER NORTH DAKOTA PROGGED
TO MARCH EAST ACROSS NORTHERN WI. NOW THE 19.00Z GFS DOES PRODUCE
SOME PRECIP FROM EAU TO LSE DURING THE EARLY AFTERNOON HOURS...BUT
APPEARS TO BE THE LONE MODEL OUT. SOUNDINGS TOO FROM THE GFS AT LSE
LOOK ODD FOR PRODUCING RAIN...HAVING JUST SOME SMALL LAYER OF
SATURATION BELOW THE CAP.
PRESSURE GRADIENT EXPECTED TO BE QUITE TIGHT TODAY OVER THE FORECAST
AREA AHEAD OF A COLD FRONT CROSSING THE DAKOTAS. WITH 850MB WINDS
INCREASING THIS AFTERNOON TO 35-50 KT SOUTHEAST TO NORTHWEST ACROSS
THE FORECAST AREA...AND DAYTIME MIXING...WE COULD SEE GUSTS UPWARDS
OF 25-35 KT. HIGHEST GUSTS ARE ANTICIPATED OVER HIGHER TERRAIN OF
SOUTHEAST MN. THESE WOULD BE JUST UNDER ADVISORY CRITERIA. REGARDING
THE AFOREMENTIONED MIXING...PERIODS OF SUN PLUS 925MB TEMPS CLIMBING
TO 16-20C BY 00Z...MOST LOCATIONS OUTSIDE OF TAYLOR/CLARK SHOULD SEE
HIGHS IN THE 70S.
FOR TONIGHT...MODELS BRING THE SHORTWAVE TROUGH INTO MN AND NORTHERN
WI...DRAGGING THE SURFACE COLD FRONT THROUGH THE NORTHWEST HALF OF
THE FORECAST AREA BY 12Z SAT. ALL MODELS SUGGEST THAT THE DPVA AHEAD
OF THE TROUGH WILL HELP COOL THE CAP...AND FORCE SOME CONVECTION TO
DEVELOP. APPEARS MUCH OF THE CONVECTION WILL BE ROOTED ABOVE THE
BOUNDARY LAYER WITH PARCELS BEING LIFTED BETWEEN 850-900MB...OR
ABOUT 1 KM ABOVE THE GROUND. CAPE LIFTED FROM THIS LEVEL RANGES FROM
1500-2000 J/KG WHILE THE 1-6KM SHEAR IS ONLY 10-15 KT. THAT SHEAR IS
CERTAINLY UNFAVORABLE FOR SEVERE. IF FOR SOME REASON THE PARCELS CAN
GET ROOTED BELOW 1 KM...THE 0-3KM SHEAR IS 35-40 KT...MUCH MORE
FAVORABLE. GIVEN THAT EQUILIBRIUM LEVELS ARE UP NEAR 40000 FT...CAN
NOT RULE OUT AN ISOLATED SEVERE STORM CAPABLE OF HAIL/WIND...WHICH
LOOKS MOST LIKELY SOMETIME IN THE LATE EVENING OR EARLY MORNING.
CONSIDERED RAISING PRECIPITATION CHANCES UP TO 60...BUT BOTH THE
19.00Z NSSL WRF-ARW AND NCEP HIRES-ARW SUGGEST ANYWHERE FROM
ISOLATED-SCATTERED COVERAGE. APPEARS THE LACK OF DECENT CONVERGENCE
BETWEEN 900-700MB IS THE CAUSE. ALL MODELS DO AGREE THAT THE BULK OF
THE CONVECTION SHOULD BE EXITING THE AREA BY 12Z. IT SHOULD
GENERALLY BE A WARM NIGHT UNTIL THE FRONTAL PASSAGE DUE TO A BREEZY
WIND AND HIGHER DEWPOINTS. AFTER FROPA...IT LOOKS LIKE A LOW STRATUS
DECK MAY FORM AS MODELS SUGGEST A SHALLOW COOL AIRMASS MOVING IN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 219 AM CDT FRI SEP 19 2014
COMPARED TO THE SHORT TERM PERIOD...GENERALLY QUIET WEATHER
DOMINATES THE LONG TERM. THERE ARE A FEW TIME PERIODS TO FOCUS ON.
GENERAL MODELS CONSENSUS IS FOR THE SHORTWAVE TROUGH TO MOVE
INTO/OVER THE FORECAST AREA BY 18Z SATURDAY...PUSHING THE COLD FRONT
ALL THE WAY THROUGH. IT APPEARS ANY CONVECTION RE-FIRING ALONG THE
COLD FRONT ON SATURDAY WILL OCCUR SOUTHEAST OF THE FORECAST AREA.
STILL MAINTAINED SOME LOW PRECIPITATION CHANCES OVER THE SOUTHEAST
HALF OF THE FORECAST AREA IN THE MORNING...THOUGH...AS WE WAIT FOR
THE SHORTWAVE TROUGH TO FULLY MOVE IN. THEN THERE SHOULD BE A
BREAK...AHEAD OF A FAIRLY POTENT SHORTWAVE DROPPING IN ON THE BACK
SIDE OF THE SHORTWAVE TROUGH OVER MN BY 00Z SUNDAY. THIS SHORTWAVE
DIVES THROUGH THE FORECAST AREA SATURDAY NIGHT. THE POTENT NATURE
COULD BE ENOUGH TO BRING SOME SHOWERS ACROSS THE FORECAST AREA...BUT
THERE IS SOME UNCERTAINTY ON MOISTURE AVAILABILITY. A LOT OF MODELS
HAVE ANY PRECIPITATION WITH THE SHORTWAVE DIMINISHING BEFORE IT
COMES INTO THE FORECAST AREA...OR MAYBE HOLDING ONTO IT FOR I-94.
SOME COLD POOL SHOWERS...ENHANCED BY A SECONDARY COLD FRONT DROPPING
THROUGH THE FORECAST AREA...COULD OCCUR ON SUNDAY ALONG AND NORTH OF
I-94. OTHERWISE...SUNDAY LOOKS SIGNIFICANTLY COOLER COMPARED TO
SATURDAY WITH 925MB TEMPS FALLING FROM 18-21C AT 00Z SUNDAY TO 11-
13C AT 18Z SUNDAY.
SUNDAY NIGHT THROUGH TUESDAY CONTINUES TO BE DOMINATED BY HIGH
PRESSURE AT THE SURFACE...WHILE VERY STRONG UPPER RIDGING MARCHES
FROM THE NORTHWESTERN U.S. INTO THE REGION. THIS SETUP WILL FAVOR A
COOL NIGHT WITH POTENTIAL FOR VALLEY FOG SUNDAY NIGHT...FOLLOWED BY
GRADUAL AIRMASS MODIFICATION AND WARMING THROUGH TUESDAY.
FOR WEDNESDAY AND THURSDAY...AN UPPER TROUGH CURRENTLY SITTING OFF
THE CALIFORNIA COAST IS PROGGED TO LIFT THROUGH THE REGION. TOUGH TO
SAY HOW MUCH MOISTURE THIS FEATURE WILL HAVE WITH IT AT THIS
TIME...AND IF ITS TRACK ENDS UP GOING THROUGH THE REGION OR STAYING
OFF TO THE WEST. THEREFORE...FOR NOW THE FORECAST JUST HAS SOME LOW
PRECIPITATION CHANCES WITH IT. TEMPERATURES COULD GET KNOCKED DOWN A
LITTLE BIT WITH THIS UPPER TROUGH MOVING THROUGH.
BEYOND THURSDAY...GOOD MODEL RUN TO RUN CONSISTENCY EXISTS THAT
THE UPPER TROUGH WILL LIFT OUT OF THE REGION...IN RESPONSE TO STRONG
UPPER RIDGING BUILDS OVER THE EASTERN TWO THIRDS OF THE COUNTRY
GOING INTO NEXT WEEKEND. THIS UPPER RIDGING SHOULD BRING DRY
CONDITIONS ALONG WITH ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1244 PM CDT FRI SEP 19 2014
THE MAIN FOCUS AT THE TAF SITES IS WITH THE POTENTIAL FOR SHOWERS
AND THUNDERSTORMS TONIGHT. THESE STORMS ARE EXPECTED TO DEVELOP
OUT AHEAD OF A COLD FRONT WHICH WILL BE DROPPING DOWN INTO THE
REGION OVERNIGHT. THE MAIN CHANCES FOR THE STORMS ARE FROM THIS
EVENING INTO THE EARLY MORNING HOURS. CONFIDENCE IS NOT HIGH
ENOUGH THAT THE CONVECTION WILL OCCUR/HIT THE TAF SITES BECAUSE
THE LATEST GUIDANCE IS SUGGESTING THAT THE MAIN SHOW MAY BE OVER
IOWA. HAVE LEFT THE VCTS IN THERE FOR THE MAIN PERIOD WHERE STORMS
ARE POSSIBLE. WINDS WILL REMAIN GUSTY INTO THE EARLY EVENING HOURS
BEFORE SWITCHING AROUND TO THE NORTHWEST AFTER THE FRONT PASSES
OVERNIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
358 PM MDT FRI SEP 19 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 350 PM MDT FRI SEP 19 2014
NEAR TERM FORECAST CONCERNS REVOLVE AROUND PCPN CHANCES FOR THE REST
OF THE AFTN AND EVE. WATER VAPOR SATELLITE SHOWS A WELL PRONOUNCED
UPPER-LEVEL SHORTWAVE MOVING ACROSS NORTHWEST WY AT 20Z. ASSOCIATED
SFC COLD FRONT HAS MADE LITTLE FORWARD PROGRESS THIS AFTN...ANALYZED
FROM SOUTHWEST TO NORTHEAST ACROSS THE STATE. THIS FEATURE COMBINED
WITH MODEST LARGER SCALE SUPPORT SHOULD SERVE AS A FOCUS FOR SHOWER
AND TSTM DEVELOPMENT IN THE NEXT FEW HOURS. HRRR HAS BEEN CONSISTENT
WITH SHOWING ISOLATED ACTIVITY FROM SOUTHEAST WY INTO THE SOUTHERN
NE PANHANDLE BETWEEN 22Z AND 02Z. LACK OF SUBSTANTIAL FORCING SHOULD
KEEP THINGS ISOLATED. GFS AND NAM BUFKIT SOUNDINGS INDICATE INVERTED
V LLVL PROFILES OVER MUCH OF THE CWA. DCAPES AROUND 1300 J/KG ON THE
LATEST SPC MESOANALYSIS SUGGESTS GUSTY OUTFLOW WINDS COULD BE A BIT
OF A PROBLEM TONIGHT. DID NOT MENTION IN THE GRIDS WITH COVERAGE NOT
HIGH ENOUGH TO WARRANT.
COLD FRONT IS PROGGED TO SWEEP ACROSS THE CWA BY LATE TONIGHT. DRIER
AIR WILL SLOWLY WORK INTO THE AREA...ENDING CHANCES FOR PCPN FROM NW
TO SE BY 06Z SAT. GFS AND NAM SHOW H7 TEMPS COOLING TO 6 TO 8 DEG C
OVER THE PLAINS BY SAT AFTN...DOWN FROM AROUND TODAYS 13 C OVER CYS
PER A RECENT LAPS SOUNDING ANALYSIS. DRY COLUMN OVERHEAD FOR SAT AS
HIGH-AMPLITUDE UPPER RIDGING TAKES OVER...SO LOOKING AT MOSTLY SUNNY
SKIES AND A SUBSTANTIAL COOLDOWN FROM TODAYS HIGHS. NEXT CONCERN IS
A LARGE CUTOFF LOW CURRENTLY SEEN ON WATER VAPOR SATELLITE OVER WEST
CENTRAL CALIFORNIA. THIS FEATURE WILL LIFT SLOWLY NORTHEAST ON SUN
WITH INCREASING 700-300 MILLIBAR MOISTURE OVER CARBON COUNTY BY 12Z.
MOISTURE AND QG ASCENT OVERSPREADS THE CWA THROUGH THE REMAINDER OF
THE FCST PERIOD. LLVL UPSLOPE AND SOME CLOUD COVER SUGGESTS SUN AFTN
SHOULD BE QUITE COOL. THE MAJORITY OF MOS GUIDANCE SUGGESTS HIGHS AT
70F OR BELOW AS A GENERAL RULE...SO TRENDED LOWER ON TEMPS. ISOLATED
TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE FROM SW
TO NE DURING THAT TIME FRAME.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 350 PM MDT FRI SEP 19 2014
MODELS ARE IN GOOD AGREEMENT AT SHOWING THE UPPER LOW OVER THE
GREAT BASIN MOVING EASTWARD ON MON AND LOCATED OVER NORTHERN WY BY
THE AFTN. GOOD UPPER LEVEL DIFFLUENCE WILL DEVELOP DURING THE
DAY...ESPECIALLY ACROSS THE PLAINS. SCATTERED SHOWERS AND TSTMS
WILL BE POSSIBLE THROUGH THE DAY. LOOKING AT SOUNDINGS AND
CONVECTIVE PARAMETERS OVER THE NEBRASKA PANHANDLE...COULD SEE A
FEW STRONGER STORMS WITH SMALL HAIL. MIDLVL LOW CONTINUES EASTWARD
INTO SOUTH DAKOTA ON MON NIGHT AND TUES WITH LARGE SCALE
SUBSIDENCE FOLLOWING. PRECIP CHANCES COME DOWN ON TUES AS THE BEST LIFT
AND MOISTURE IS WELL EAST...HOWEVER KEPT SLIGHT CHANCE POPS DURING
TH AFTN WITH WEAK INSTABILITY COMBINED WITH MODEST MIDLVL
MOISTURE ON THE BACKSIDE OF THE LOW. IT WILL BE BREEZY ON TUES
WITH ENHANCED NORTHWEST FLOW ALOFT AND GOOD MIXING. THE REMAINDER
OF THE LONG TERM WILL FEATURE INCREASING HEIGHTS AS A RIDGE BUILDS
OVER THE INTERMOUNTAIN WEST IN ADVANCE OF A LARGE SCALE TROUGH OFF
THE WEST COAST. TEMPS WILL BE SLIGHTLY ABOVE SEASONAL NORMS AND
WINDS WILL BE RELATIVELY WEAK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1142 AM MDT FRI SEP 19 2014
A WEAK FRONT IS CURRENTLY MOVING ACROSS THE REGION. WINDS ARE NOT
EXPECTED TO BE STRONG WITH THIS FRONTAL PASSAGE...GENERALLY LESS
THAN 15 KTS. SCATTERED SHOWERS AND ISOLATED TSTMS COULD DEVELOP
THIS AFTERNOON IN AREAS NEAR THE COLORADO BORDER...STRETCHING FROM
LARAMIE EASTWARD TO SIDNEY. GUSTY WINDS WILL BE THE PRIMARY THREAT
WITH THE SHOWERS. SHOWER ACTIVITY WILL DIMINISH AFTER AROUND 01Z
WITH CLEARING SKIES OVERNIGHT.
&&
.FIRE WEATHER...
ISSUED AT 350 PM MDT FRI SEP 19 2014
A WEAK COLD FRONT WILL MOVE ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE TONIGHT. ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS
WILL BE POSSIBLE THROUGH THE AFTN AND EVE WITH GUSTY OUTFLOW WINDS
THE PRIMARY HAZARD. COOLER AND DRIER FOR SAT IN THE POST-FRONTAL AIR
MASS WITH LITTLE OR NO CHANCE FOR PCPN. THE NEXT CHANCE FOR WETTING
RAINS WILL BE FROM SUN NIGHT THROUGH TUE AS A POTENT WEATHER SYSTEM
MOVES SLOWLY NORTHEAST ACROSS THE REGION. CRITICAL FIRE WEATHER IS
NOT EXPECTED IN THE FORESEEABLE FUTURE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...HAMMER
LONG TERM...FINCH
AVIATION...FINCH
FIRE WEATHER...HAMMER