Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/20/14
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
122 AM CDT THU SEP 18 2014
.AVIATION...18/06Z TAF CYCLE
DENSE FOG HAS DVLPD ACRS N-CNTRL AR...WITH KHRO AND KBPK SEEING
VBSYS AOB 1/2SM. EXPECT THESE CONDS TO PERSIST THRU THE OVERNIGHT
HRS. THE EXCEPTION WL BE IF ANY UPSTREAM CONVECTION ACRS SWRN MO
MANAGES TO AFFECT THESE LOCATIONS...WITH VCTS INCLUDED.
ELSEWHERE...EXPECT TO SEE LOW CLOUDS AND PTCHY BR DVLP THRU THE
EARLY MRNG HRS...WITH OCNL MVFR CONDS THRU MID THU MRNG. CANNOT
RULE OUT ADDITIONAL CONVECTION LATER IN THE DAY...BUT LOW
CONFIDENCE WL PRECLUSE A MENTION IN THE FCST ATTM. /44/
&&
.PREV DISCUSSION... /ISSUED 1208 AM CDT THU SEP 18 2014/
UPDATE...
UPDATED THE FORECAST TO DECREASE RAIN CHANCES OVERNIGHT IN THE
CENTRAL AND EAST SECTIONS. THUNDERSTORMS CONTINUE TO MOVE SOUTH
ALONG THE OKLAHOMA BORDER AND ARE GENERALLY WEAKENING IN ARKANSAS.
ALSO INCREASED CLOUD COVER OVER THE AREA.
PREV DISCUSSION... /ISSUED 149 PM CDT WED SEP 17 2014/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
AREA OF SHRA/TSRA ONGOING ACROSS SRN MO IS BEGINNING TO ACCELERATE
AS THE STRONGEST CELLS ALONG THE WRN HALF OF THIS COMPLEX DROPS SOUTH
INTO AR. SEVERAL OF THE RECENT RUNS OF THE HIGH-RES HRRR HAVE DONE A
REASONABLE JOB ON THESE FEATURES...AND SHOW THIS ACTIVITY DROPPING
GENERALLY SOUTH THROUGHOUT THE AFTERNOON HRS. EXPECTING THIS
ACTIVITY TO GENERALLY FOLLOW THE HIGHER INSTABILITY AXIS ACROSS
THE WRN HALF TO TWO-THIRDS OF THE STATE WHERE MOST UNSTABLE CAPE
VALUES ARE ON THE ORDER OF 1-3K J/KG AT THIS HR. AS A RESULT...DO
HAVE HIGHEST POPS THROUGH MID AFTERNOON OVER THE NRN AND NWRN
SECTIONS OF THE CWA...THEN DROPPING SOUTH TO SW OVER TIME LATER
THIS AFTERNOON. THE HRRR SOLUTIONS EVEN KEEP THIS ACTIVITY GOING
INTO THE SWRN SECTIONS OF THE AREA BY THIS EVENING...SO HAVE
GENERALLY FOLLOWED THIS TREND WITH POPS. HOWEVER...DO DROP POPS
OVER TIME AS UNCERTAINTY IN COVERAGE AN INTENSITY INCREASES BY
LATE THIS EVENING REGARDING THIS ONGOING CONVECTIVE ACTIVITY.
BEYOND THIS EVENING...THE TIMING AND PLACEMENT OF WHAT MAY BE THE
NEXT UPPER DISTURBANCE MOVING OVER THE STATE BECOMES A BIT
UNCERTAIN. EARLIER SHORT TERM MODEL SOLUTIONS HAVE THE NEXT WAVE
MOVING OVER LATE TONIGHT INTO THU MORNING...BUT THIS MAY NOT BE THE
CASE WITH THE ONGOING ACTIVITY AND ITS EXPECTED PATH. THE NEXT WAVE
MAY BE DELAYED A BIT LONGER...BUT MAY ALSO NOT BE AS INTENSE AS
EARLIER EXPECTED. WITH THAT SAID...CONTINUE WITH GENERALLY LOCATION
OF CHANCE POPS FOR MUCH OF THU...BUT HAVE DECREASED POPS SOME AS A
RESULT OF THE UNCERTAINTY OF WHEN/WHERE THE NEXT WAVE MAY MOVE.
BY FRI INTO EARLY SAT...AN UPPER RIDGE WILL MOVE OVER THE
REGION...DECREASING POPS AND INCREASING TEMPS ACROSS THE STATE. BY
LATE IN THE PERIOD THOUGH...HAVE INCREASING POPS WITH THE APPROACH
OF AN UPPER LOW OR THE REMNANTS OF ODILE AS THEY APPROACH FROM THE
WEST/NW.
LONG TERM...SUNDAY THROUGH WEDNESDAY
A COLD FRONT WILL BE MAKING ITS WAY THROUGH THE STATE AT THE START
OF THE LONG TERM...WITH SOME RAIN CHANCES MAKING THEIR WAY INTO THE
AREA THROUGH MONDAY AFTERNOON. THOUGH...LATEST MODEL SOLUTIONS SEEM
LESS AMBITIOUS ABOUT WIDESPREAD RAINFALL IN THE STATE.
AS RAIN CHANCES DISSIPATE BY MONDAY...COOLER AIR WILL FILTER INTO THE
STATE. BOTH HIGH AND LOW TEMPERATURES WILL BE FAIRLY NORMAL TO
SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF SEPTEMBER IN ARKANSAS.
WINDS WILL GENERALLY BE OUT OF THE NORTH THROUGH THE EXTENDED PERIOD
AND A COOL NORTHWEST FLOW ALOFT WILL BE IN PLACE.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1208 AM CDT THU SEP 18 2014
.UPDATE...
UPDATED THE FORECAST TO DECREASE RAIN CHANCES OVERNIGHT IN THE
CENTRAL AND EAST SECTIONS. THUNDERSTORMS CONTINUE TO MOVE SOUTH
ALONG THE OKLAHOMA BORDER AND ARE GENERALLY WEAKENING IN ARKANSAS.
ALSO INCREASED CLOUD COVER OVER THE AREA.
&&
.PREV DISCUSSION... /ISSUED 647 PM CDT WED SEP 17 2014/
AVIATION...
CONVECTION WILL REMAIN ACROSS THE WEST THIS EVENING..AND HAVE VCTS
IN THE TWO WESTERN TAFS THROUGH THE EVENING HOURS. SHORT TERM
GUIDANCE HAS A BREAK IN THE CONVECTION...BEFORE ANOTHER SYSTEM
POTENTIALLY DEVELOPS OVERNIGHT. DUE TO LOW CONFIDENCE...HAVE VCSH
ACROSS THE NORTH. MVFR CONDITIONS WILL DEVELOP ACROSS THE NORTHERN
HALF WITH THE LOW LEVEL MOISTURE OVERNIGHT...AND MAY BECOME IFR.
PREV DISCUSSION... /ISSUED 149 PM CDT WED SEP 17 2014/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
AREA OF SHRA/TSRA ONGOING ACROSS SRN MO IS BEGINNING TO ACCELERATE
AS THE STRONGEST CELLS ALONG THE WRN HALF OF THIS COMPLEX DROPS SOUTH
INTO AR. SEVERAL OF THE RECENT RUNS OF THE HIGH-RES HRRR HAVE DONE A
REASONABLE JOB ON THESE FEATURES...AND SHOW THIS ACTIVITY DROPPING
GENERALLY SOUTH THROUGHOUT THE AFTERNOON HRS. EXPECTING THIS
ACTIVITY TO GENERALLY FOLLOW THE HIGHER INSTABILITY AXIS ACROSS
THE WRN HALF TO TWO-THIRDS OF THE STATE WHERE MOST UNSTABLE CAPE
VALUES ARE ON THE ORDER OF 1-3K J/KG AT THIS HR. AS A RESULT...DO
HAVE HIGHEST POPS THROUGH MID AFTERNOON OVER THE NRN AND NWRN
SECTIONS OF THE CWA...THEN DROPPING SOUTH TO SW OVER TIME LATER
THIS AFTERNOON. THE HRRR SOLUTIONS EVEN KEEP THIS ACTIVITY GOING
INTO THE SWRN SECTIONS OF THE AREA BY THIS EVENING...SO HAVE
GENERALLY FOLLOWED THIS TREND WITH POPS. HOWEVER...DO DROP POPS
OVER TIME AS UNCERTAINTY IN COVERAGE AN INTENSITY INCREASES BY
LATE THIS EVENING REGARDING THIS ONGOING CONVECTIVE ACTIVITY.
BEYOND THIS EVENING...THE TIMING AND PLACEMENT OF WHAT MAY BE THE
NEXT UPPER DISTURBANCE MOVING OVER THE STATE BECOMES A BIT
UNCERTAIN. EARLIER SHORT TERM MODEL SOLUTIONS HAVE THE NEXT WAVE
MOVING OVER LATE TONIGHT INTO THU MORNING...BUT THIS MAY NOT BE THE
CASE WITH THE ONGOING ACTIVITY AND ITS EXPECTED PATH. THE NEXT WAVE
MAY BE DELAYED A BIT LONGER...BUT MAY ALSO NOT BE AS INTENSE AS
EARLIER EXPECTED. WITH THAT SAID...CONTINUE WITH GENERALLY LOCATION
OF CHANCE POPS FOR MUCH OF THU...BUT HAVE DECREASED POPS SOME AS A
RESULT OF THE UNCERTAINTY OF WHEN/WHERE THE NEXT WAVE MAY MOVE.
BY FRI INTO EARLY SAT...AN UPPER RIDGE WILL MOVE OVER THE
REGION...DECREASING POPS AND INCREASING TEMPS ACROSS THE STATE. BY
LATE IN THE PERIOD THOUGH...HAVE INCREASING POPS WITH THE APPROACH
OF AN UPPER LOW OR THE REMNANTS OF ODILE AS THEY APPROACH FROM THE
WEST/NW.
LONG TERM...SUNDAY THROUGH WEDNESDAY
A COLD FRONT WILL BE MAKING ITS WAY THROUGH THE STATE AT THE START
OF THE LONG TERM...WITH SOME RAIN CHANCES MAKING THEIR WAY INTO THE
AREA THROUGH MONDAY AFTERNOON. THOUGH...LATEST MODEL SOLUTIONS SEEM
LESS AMBITIOUS ABOUT WIDESPREAD RAINFALL IN THE STATE.
AS RAIN CHANCES DISSIPATE BY MONDAY...COOLER AIR WILL FILTER INTO THE
STATE. BOTH HIGH AND LOW TEMPERATURES WILL BE FAIRLY NORMAL TO
SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF SEPTEMBER IN ARKANSAS.
WINDS WILL GENERALLY BE OUT OF THE NORTH THROUGH THE EXTENDED PERIOD
AND A COOL NORTHWEST FLOW ALOFT WILL BE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 62 83 63 87 / 10 10 10 10
CAMDEN AR 68 89 69 90 / 20 10 10 10
HARRISON AR 61 80 63 82 / 10 10 10 20
HOT SPRINGS AR 67 85 67 86 / 20 10 10 20
LITTLE ROCK AR 66 86 66 88 / 20 10 10 10
MONTICELLO AR 67 88 68 89 / 20 10 10 10
MOUNT IDA AR 65 84 67 86 / 20 10 10 20
MOUNTAIN HOME AR 60 81 63 84 / 10 10 10 20
NEWPORT AR 61 83 62 87 / 10 10 10 10
PINE BLUFF AR 66 87 66 89 / 20 10 10 10
RUSSELLVILLE AR 65 84 66 86 / 10 10 10 20
SEARCY AR 63 83 64 87 / 10 10 10 10
STUTTGART AR 65 85 64 87 / 20 10 10 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
51
AREA FORECAST DISCUSSION
NWS RENO NV
309 PM PDT THU SEP 18 2014
.SYNOPSIS...
SMOKE FROM THE KING FIRE WILL AFFECT PARTS OF THE REGION THROUGH
TONIGHT. AS WINDS SHIFT TO THE EAST FROM FRIDAY THROUGH THE
WEEKEND, SMOKE WILL REMAIN WEST OF THE SIERRA CREST. LOW PRESSURE
MOVING INTO NORTHERN CALIFORNIA WILL BRING A CHANCE OF
THUNDERSTORMS TODAY AND TONIGHT. THUNDERSTORM CHANCES WILL
DECREASE FRIDAY AS THIS LOW MOVES FARTHER SOUTH.
&&
.SHORT TERM...
UPPER LEVEL LOW CONTINUES TO PUSH DOWN ALONG THE CALIFORNIA COAST
THROUGH TONIGHT WITH SOUTHWEST FLOW ALOFT. TEMPERATURES WILL BE A
BIT COOLER TODAY AND FRIDAY AS THE LOW BRING DOWN TEMPERATURES
ALOFT. BY FRIDAY, THE LOW BECOMES CUT OFF FROM THE MAIN JET OVER
THE PAC NORTHWEST AND MEANDERS AROUND THE CALIFORNIA COAST THROUGH
THE WEEKEND.
SMOKE FROM THE KING FIRE WEST OF TAHOE WILL CONTINUE TO FLOW INTO
THE NORTH TAHOE AND RENO AREAS THROUGH THIS EVENING AND TONIGHT.
BY TONIGHT, WINDS WILL BEGIN TO SHIFT TO THE EAST, HELPING TO
IMPROVE THE SMOKEY SKIES FRIDAY AND SATURDAY. THERE IS MEDIUM TO
HIGH CONFIDENCE THAT THE WINDS WILL REMAIN OUT OF THE EAST THROUGH
THE WEEKEND WITH IMPROVING CONDITIONS OVER WESTERN NEVADA. AS FOR
LAKE TAHOE THIS WEEKEND, SATURDAY LOOKS PRETTY GOOD FOR EASTERLY
WINDS KEEPING SMOKE OUT OF THE BASIN, ALTHOUGH BY SUNDAY THERE MAY
BE SOME SMOKE CREEPING BACK INTO THE BASIN LATE IN THE DAY AS
LIGHT WESTERLY WINDS RETURN. THIS COULD IMPACT WEEKEND EVENTS
AROUND LAKE TAHOE
AS THE LOW CONTINUES TO DROP SOUTH, A FEW SHOWERS AND
THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND TONIGHT IN
WESTERN NEVADA. DEFORMATION ZONE OF THE LOW WILL HELP TO CREATE
SOME ADDED LIFT IN THE ATMOSPHERE. ANY PRECIPITATION FROM THESE
SHOWERS WILL ALSO HELP TO GET SOME OF THE PARTICULATES OUT OF THE
AIR AS WELL. THERE MAY BE AN AREA OF HEAVIER PRECIPITATION IN
WESTERN NEVADA TONIGHT, THE NAM AND HRRR ARE ACTUALLY STARTING TO
SHOW SOME AREAS OF HEAVIER PRECIPITATION ASSOCIATED WITH THIS
DEFORMATION ZONE OVERNIGHT. WE WILL HAVE TO KEEP A CLOSE EYE ON
THIS POTENTIAL.
BY FRIDAY AND SATURDAY, THE LOW DROPS OFF THE CA COAST SLIGHTLY, BUT
HELPS TO BRING SOUTHEAST FLOW AND INCREASED CONVERGENCE/MOISTURE OVER
THE EASTERN SIERRA. THIS WILL KEEP A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST MAINLY SOUTH OF HIGHWAY 50 ON FRIDAY
AND CREEPING UP INTO THE TAHOE BASIN BY SATURDAY AND SATURDAY
NIGHT. HOON
.LONG TERM...SUNDAY THROUGH THURSDAY...
THE MAIN CHANGE TO THE LONG TERM FORECAST WAS TO INCREASE CHANCES
FOR PRECIPITATION ON SUNDAY. THE CLOSED LOW THAT WAS SITTING OVER
SOUTHERN CALIFORNIA WILL BEGIN TO OPEN AND LIFT TOWARD THE NORTHEAST
SUNDAY INTO MONDAY. AS IT LIFTS, WRAP AROUND MOISTURE FORMS A BAND
OF PRECIPITATION ALONG A DEFORMATION AXIS IN THE NORTHEAST QUADRANT
OF THE LOW. YESTERDAY, ONLY THE EC WAS SHOWING THIS SOLUTION, AND
WHILE IT IS STILL THE MOST ROBUST, OTHER OPERATIONAL MODELS ARE NOW
COMING AROUND TO THIS SOLUTION AS WELL. THEREFORE, POPS WERE
INCREASED FOR THE PERIOD, THOUGH DEPENDING ON MODEL TRENDS, IT IS
POSSIBLE THEY WILL NEED TO BE BOOSTED FURTHER. WHILE NOT OVERLY
IMPRESSIVE, THUNDERSTORMS ARE A POSSIBILITY SUNDAY AFTERNOON DUE TO
FORCING FROM THE LOW AND MID-LEVEL INSTABILITY.
SHORTWAVE RIDGING BUILDS IN BEHIND THE EXITING LOW MONDAY INTO
TUESDAY FOR DRY AND STABLE CONDITIONS AND TEMPERATURES NEAR NORMAL.
SOUTHWEST WINDS ARE EXPECTED TO INCREASE WEDNESDAY AND THURSDAY
AHEAD OF AN APPROACHING COLD FRONT AND DEEP TROUGH. IF THE KING FIRE
IS STILL ACTIVELY BURNING, THIS WILL LIKELY BRING ANOTHER LARGE PUSH
OF SMOKE INTO THE SIERRA AND NORTHWEST NEVADA, BUT TIME WILL TELL
HOW THE FIRE EVOLVES. THERE IS DECENT LARGE SCALE MODEL AGREEMENT
WITH THE TROUGH PUSHING INTO NORTHEAST CALIFORNIA AND NORTHWEST
NEVADA ON THURSDAY WITH PRECIPITATION AND MUCH COOLER TEMPERATURES
POSSIBLE. DJ
&&
.AVIATION...
THE GREATEST AVIATION CONCERN CONTINUES TO BE SMOKE FROM THE KING
FIRE WITH MOST DRASTIC VISIBILITY RESTRICTIONS FROM THE WEST SIDE OF
TAHOE EXTENDING NORTHEAST THROUGH THE GREATER RENO AREA, PAST
PYRAMID LAKE AND INTO KWMC. BOTH KTRK AND KRNO ARE REPORTING 2SM
VISIBILITY AND WIDESPREAD TERRAIN OBSCURATION IS PRESENT THROUGHOUT
THE AREA. GUSTY SOUTHWEST TO WEST WINDS WILL BECOME MORE
NORTHWESTERLY IN THE LATE AFTERNOON WHICH COULD SHIFT SMOKE INTO
KTVL AND KCXP AS WELL. SMOKE WILL LIKELY DISSIPATE OVERNIGHT AS THE
WINDS LIGHTEN AND TURN TO THE NORTH, AND WITH EASTERLY FLOW FRIDAY
AND SATURDAY, TERMINALS WILL REMAIN SMOKE FREE.
THUNDERSTORMS ARE LOOKING LESS LIKELY THIS AFTERNOON WITH THE BEST
INSTABILITY IN NORTHEAST NEVADA. THERE IS A 15 PERCENT CHANCE AN
ISOLATED STORM COULD POP UP, BUT ANY STORMS THAT DO FORM WOULD BE
SHORT-LIVED WITH THE BIGGEST THREAT GUSTY AND ERRATIC WINDS. DJ
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1103 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF RAIN
SHOWERS TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH
AND IN COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL
AVERAGES TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND
SATURDAY. DRY CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT
PACIFIC WEATHER SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD
MIDWEEK.
&&
.DISCUSSION...AS OF 08:52 AM PDT THURSDAY...RAIN SHOWERS CONTINUE
TO MOVE ACROSS THE REGION WITH THE MID/UPPER LEVEL TROUGH
CURRENTLY PUSHING INTO NORTHERN CALIFORNIA. CANNOT RULE OUT A
THUNDERSTORM OR TWO OVER THE NORTH BAY THIS AFTERNOON WITH A
NEARLY 90KT UPPER LEVEL JET AND SHORT-WAVE MOVING ACROSS THE
REGION. PRECIPITATION CHANCES DIMINISH BY TONIGHT AS THE UPPER LEVEL
SUPPORT SHIFTS SOUTHWARD AND THE TROUGH MOVES FURTHER INLAND. THE
ONGOING FORECAST REFLECTS OUR LATEST ANALYSIS AND NO UPDATES ARE
EXPECTED AT THIS TIME.
AS OF THIS MORNING...THE SANTA CRUZ MOUNTAINS HAVE RECEIVED THE
MOST PRECIPITATION WITH AMOUNTS UPWARDS OF 0.60" DURING THE PAST
12 HOURS. NORTH BAY MOUNTAIN LOCATIONS HAVE REPORTED BETWEEN 0.25"
AND 0.50" WHILE AMOUNTS UP TO 0.25" FELL OVER PORTIONS OF THE
SANTA LUCIA MOUNTAINS DURING THE SAME TIME FRAME.
&&
.PREV DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 11:03 AM PDT THURSDAY...A PACIFIC STORM SYSTEM
IS WORKING ITS WAY TOWARDS THE CENTRAL COAST THIS MORNING. THE
WARM FRONT PORTION OF THIS STORM SYSTEM IS POSITIONED ALONG THE
COAST PROMOTING SCATTERED SHOWERS. SOUTHERLY WINDS ARE ENHANCING
THE LOCAL DEW POINT BUT THE WINDS ARE ANTICIPATED TO SHIFT TO THE
WEST BEGINNING LATER THIS AFTERNOON AS THE STORM SYSTEM CONTINUES
TO PUSH SOUTH.
VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TO PERSIST TODAY
WITH A POSSIBILITY OF A SHOWER BETWEEN 1800 AND 2100Z. SOUTHERLY
WINDS WILL BECOME WESTERLY THIS EVENING.
CONFIDENCE MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS ARE EXPECTED TO PREVAIL
TODAY WITH OCCASIONAL SHOWERS POSSIBLE BETWEEN 1800 AND 2300Z.
CONFIDENCE MODERATE.
&&
.MARINE...AS OF 11:03 AM PDT THURSDAY...A STORM SYSTEM CENTERED
APPROXIMATELY 200 MILES OFF OF CAPE MENDOCINO WILL MAINTAIN LIGHT
TO OCCASIONALLY MODERATE SOUTHERLY WINDS ACROSS THE COASTAL WATERS
INTO THE OVERNIGHT HOURS. WINDS WILL BECOME NORTHWEST FRIDAY AS
THE STORM SYSTEM PUSHES SOUTHEAST. A LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL CONTINUE TO IMPACT THE WATERS THROUGH
THIS EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RG/KBB
AVIATION: LARRY
MARINE: LARRY
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
906 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF RAIN
SHOWERS TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH
AND IN COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL
AVERAGES TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND
SATURDAY. DRY CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT
PACIFIC WEATHER SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD
MIDWEEK.
&&
.DISCUSSION...AS OF 08:52 AM PDT THURSDAY...RAIN SHOWERS CONTINUE
TO MOVE ACROSS THE REGION WITH THE MID/UPPER LEVEL TROUGH
CURRENTLY PUSHING INTO NORTHERN CALIFORNIA. CANNOT RULE OUT A
THUNDERSTORM OR TWO OVER THE NORTH BAY THIS AFTERNOON WITH A
NEARLY 90KT UPPER LEVEL JET AND SHORT-WAVE MOVING ACROSS THE
REGION. PRECIPITATION CHANCES DIMINISH BY TONIGHT AS THE UPPER LEVEL
SUPPORT SHIFTS SOUTHWARD AND THE TROUGH MOVES FURTHER INLAND. THE
ONGOING FORECAST REFLECTS OUR LATEST ANALYSIS AND NO UPDATES ARE
EXPECTED AT THIS TIME.
AS OF THIS MORNING...THE SANTA CRUZ MOUNTAINS HAVE RECEIVED THE
MOST PRECIPITATION WITH AMOUNTS UPWARDS OF 0.60" DURING THE PAST
12 HOURS. NORTH BAY MOUNTAIN LOCATIONS HAVE REPORTED BETWEEN 0.25"
AND 0.50" WHILE AMOUNTS UP TO 0.25" FELL OVER PORTIONS OF THE
SANTA LUCIA MOUNTAINS DURING THE SAME TIME FRAME.
&&
.PREV DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 4:55 AM PDT THURSDAY...SCATTERED RAIN SHOWERS
WILL CONTINUE THROUGH A LEAST MIDDAY TODAY AS A LOW PRESSURE
SYSTEM SLIDES SOUTH ALONG THE COAST. SHOWERS WILL GRADUALLY TAPER
THIS AFTERNOON INTO THE EVENING. MVFR EXPECTED THROUGH MUCH OF THE
DAY WITH LOW CLOUDS ANTICIPATED TO RETURN THURSDAY EVENING. LIGHT
TO MODERATE WINDS WILL PERSIST THROUGH THE FORECAST PERIOD.
MODERATE TO HIGH CONFIDENCE.
VICINITY OF KSFO...LIGHT DRIZZLE HAS FALLEN UPON AREA TERMINALS
OVERNIGHT RESULTING IN WET RUNWAYS THIS MORNING. SCATTERED
SHOWERS POSSIBLE THROUGH THE DAY. MVFR CIGS WILL LIFT THIS
AFTERNOON WITH TEMPO SCATTERING POSSIBLE. LOW CLOUDS EXPECTED TO
RETURN AROUND 06Z-07Z TONIGHT. WINDS WILL REMAIN LIGHT THROUGH THE
MORNING THEN EXPECTED TO STRENGTHEN IN THE AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR TO VFR CIGS ANTICIPATED TO
PERSIST THROUGH TODAY WITH SCATTERED SHOWERS POSSIBLE. IFR CIGS
FORECAST TO RETURN AFTER 06Z TONIGHT. LIGHT WINDS WILL STRENGTHEN
TO AROUND 10 KT IN THE AFTERNOON.
&&
.MARINE...AS OF 2:55 AM PDT THURSDAY...A LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL IMPACT THE WATERS THROUGH THIS EVENING. A
LOW CENTERED APPROX 435 NM DUE WEST OF POINT ARENA WILL MOVE
THROUGH THE NORTHERN WATERS TODAY RESULTING IN LIGHT SOUTHERLY
WINDS AND SCATTERED SHOWERS. THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS NORTH OF POINT REYES AND IN THE SAN FRANCISCO BAY
THIS AFTERNOON. WINDS WILL BECOME LIGHT TO MODERATE NORTHWEST
FRIDAY THROUGH SUNDAY AFTER THE LOW MOVES INLAND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RG/KBB
AVIATION/MARINE: CW
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
509 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF LIGHT
RAIN TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH AND IN
COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL AVERAGES
TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND SATURDAY. DRY
CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT PACIFIC WEATHER
SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD MIDWEEK.
&&
.DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 4:55 AM PDT THURSDAY...SCATTERED RAIN SHOWERS
WILL CONTINUE THROUGH A LEAST MIDDAY TODAY AS A LOW PRESSURE
SYSTEM SLIDES SOUTH ALONG THE COAST. SHOWERS WILL GRADUALLY TAPER
THIS AFTERNOON INTO THE EVENING. MVFR EXPECTED THROUGH MUCH OF THE
DAY WITH LOW CLOUDS ANTICIPATED TO RETURN THURSDAY EVENING. LIGHT
TO MODERATE WINDS WILL PERSIST THROUGH THE FORECAST PERIOD.
MODERATE TO HIGH CONFIDENCE.
VICINITY OF KSFO...LIGHT DRIZZLE HAS FALLEN UPON AREA TERMINALS
OVERNIGHT RESULTING IN WET RUNWAYS THIS MORNING. SCATTERED
SHOWERS POSSIBLE THROUGH THE DAY. MVFR CIGS WILL LIFT THIS
AFTERNOON WITH TEMPO SCATTERING POSSIBLE. LOW CLOUDS EXPECTED TO
RETURN AROUND 06Z-07Z TONIGHT. WINDS WILL REMAIN LIGHT THROUGH THE
MORNING THEN EXPECTED TO STRENGTHEN IN THE AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR TO VFR CIGS ANTICIPATED TO
PERSIST THROUGH TODAY WITH SCATTERED SHOWERS POSSIBLE. IFR CIGS
FORECAST TO RETURN AFTER 06Z TONIGHT. LIGHT WINDS WILL STRENGTHEN
TO AROUND 10 KT IN THE AFTERNOON.
&&
.MARINE...AS OF 2:55 AM PDT THURSDAY...A LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL IMPACT THE WATERS THROUGH THIS EVENING. A
LOW CENTERED APPROX 435 NM DUE WEST OF POINT ARENA WILL MOVE
THROUGH THE NORTHERN WATERS TODAY RESULTING IN LIGHT SOUTHERLY
WINDS AND SCATTERED SHOWERS. THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS NORTH OF POINT REYES AND IN THE SAN FRANCISCO BAY
THIS AFTERNOON. WINDS WILL BECOME LIGHT TO MODERATE NORTHWEST
FRIDAY THROUGH SUNDAY AFTER THE LOW MOVES INLAND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: KBB
AVIATION/MARINE: CW
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
349 AM PDT THU SEP 18 2014
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF LIGHT
RAIN TO PARTS OF THE REGION TODAY...MAINLY ACROSS THE NORTH AND IN
COASTAL AREAS. TEMPERATURES WILL COOL BELOW SEASONAL AVERAGES
TODAY WITH SOME WARMING ESPECIALLY INLAND FRIDAY AND SATURDAY. DRY
CONDITIONS WILL RETURN BY TONIGHT WITH THE NEXT PACIFIC WEATHER
SYSTEM APPROACHING NORTHERN CALIFORNIA TOWARD MIDWEEK.
&&
.DISCUSSION...AS OF 03:11 AM PDT THURSDAY...A WEAK PACIFIC COLD
FRONT IS WORKING ONSHORE THIS MORNING WITH AN UPPER TROF OFF THE
COAST. SATELLITE IMAGERY SHOWS WIDE SWATH OF LOW LEVEL CLOUDS
MOVING ONSHORE IN BOUNDARY LAYER SW FLOW. PRECIPITATION HAS BEEN
PRIMARILY CONFINED TO FAVORABLE OROGRAPHIC AREAS IN SW FLOW IN THE
NORTH BAY AND SANTA CRUZ MOUNTAINS. HRRR GUIDANCE INDICATES SOME
LIGHT PRECIPITATION WILL OCCUR THIS MORNING ON THE WEST SLOPES OF
THE SANTA LUCIA RANGE AS WELL. AMOUNTS SO FAR HAVE BEEN MOSTLY
UNDER A QUARTER INCH WITH RAIN SHADOWED AREAS RECEIVING LITTLE TO
NO RAINFALL. LOOK FOR AN ADDITIONAL TENTH OF AN INCH OR SO IN
FAVORED UPSLOPE AREAS THIS MORNING WHILE MOST AREAS GET VERY
LITTLE RAINFALL.
BASED ON NAM PROJECTED SOUNDINGS...WOULD EXPECT A FEW BREAKS IN
THE CLOUDS LATER THIS MORNING WHICH MATCHES WELL WITH BREAK WELL
OFFSHORE AT TIME. WITH A LITTLE BIT OF SUNSHINE...NORTH BAY COULD
SEE A FEW MORE SHOWERS THIS AFTERNOON WITH A VERY SLIGHT CHANCE OF
THUNDERSTORMS IF ENOUGH HEATING TO BREAK CAP AROUND 750 MB. CAPES
BARELY EXCEED 200J THIS AFTERNOON SO CONVECTIVE THREAT IS MINIMAL. BEST
CHANCE FOR THUNDER WOULD BE INTERIOR MOUNTAINS OF SONOMA COUNTY.
FROM THE BAY AREA SOUTH...WOULD EXPECT GRADUAL CLEARING AFTER LATE
THIS MORNING.
MAIN IMPACTS THIS MORNING WILL BE AREAS OF DAMP OR WET ROADS FROM
LIGHT RAIN OR DRIZZLE. ANY MOISTURE ON ROAD SURFACES COULD PRODUCE
SLICK CONDITIONS SINCE ITS BEEN SO LONG SINCE SIGNIFICANT RAINFALL
HAS OCCURRED.
THE TROF WILL SAG SOUTHWARD AND CLOSE OFF AN UPPER LOW NEAR THE SOUTHERN
CALIFORNIA COAST BY SATURDAY. EVEN THOUGH UPPER WINDS BECOME
EASTERLY...DO NOT EXPECT SURFACE FLOW TO RESPOND WITH THE CLOSED
CYCLONIC CIRCULATION ALOFT AND SURFACE LOW REFLECTION REMAINING
INLAND OVER NORTHERN CALIFORNIA. BELIEVE ONSHORE FLOW WILL CONTINUE INTO
WEEKEND SO PRIMARY WARMING WILL BE INLAND AND ACROSS A GOOD
PORTION OF THE NORTH BAY. MAIN IMPACT WILL BE A SHALLOWER MARINE
LAYER SLOPING DEEPER TOWARD THE SOUTH.
THE UPPER LOW GETS EJECTED INLAND LATER IN THE WEEKEND WITH
TEMPORARY HIGH PRESSURE RETURNING TO THE COAST. ANOTHER PACIFIC SYSTEM
WILL APPROACH THE STATE TOWARD MIDWEEK. MODELS ARE COMING INTO
BETTER AGREEMENT THAT THIS FEATURE COULD BRING RAIN TO AT LEAST
NORTHERN CALIFORNIA BY THURSDAY...BUT TIMING AND AMOUNTS ARE STILL
UNCERTAIN.
&&
.AVIATION...AS OF 10:00 PM PDT WEDNESDAY...RAIN...MOSTLY LIGHT IN
INTENSITY AND ON THE IMMEDIATE COAST CONTINUES TO MOVE SOUTH THIS
EVENING. CIGS AT AREA TERMINALS WILL GRADUALLY LOWER TO MVFR
LEVELS OVERNIGHT.
VICINITY OF KSFO...LIGHT DRIZZLE REPORTED AT KSFO NOW. THE LOWER TO
MID LEVEL CLOUDS WILL MOVE IN LATER TONIGHT. MVFR CIGS WITH LIGHT
RAIN LATE TONIGHT. WET RUNWAYS.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR HOLDING TOGETHER SO FAR BUT POTENTIAL
IS THERE FOR LOW CLOUD DEVELOPMENT AHEAD OF THE INCOMING LOW.
CLOUD LAYERS TONIGHT FORECAST TO BE PRIMARILY MVFR.
&&
.MARINE...AS OF 6:35 PM PDT WEDNESDAY...VERY LARGE LONG PERIOD
SOUTHWESTERLY SWELL WILL IMPACT THE WATERS THROUGH THURSDAY. A LOW
IS CENTERED 350 MILES WEST OF UKIAH. THIS LOW WILL MOVE THROUGH
THE NORTHERN WATERS ON THURSDAY RESULTING IN LIGHT SOUTHERLY WINDS
WITH A CHANCE OF SHOWERS. THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS THIS EVENING NORTH OF POINT REYES AND IN THE SAN
FRANCISCO BAY THURSDAY. WINDS WILL BECOME LIGHT TO MODERATE
NORTHWEST FRIDAY THROUGH SUNDAY AFTER THE LOW MOVES INLAND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: KBB
AVIATION: CANEPA
MARINE: W PI/CANEPA
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1211 PM EDT THU SEP 18 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE THROUGH OUR AREA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL THEN BUILD IN TONIGHT INTO FRIDAY,
BEFORE SHIFTING OFFSHORE FRIDAY NIGHT. A WARM FRONT WILL LIFT TO
OUR NORTHWEST SATURDAY, THEN A COLD FRONT IS EXPECTED TO ARRIVE
LATE SUNDAY INTO MONDAY. THIS FRONT WILL SETTLE TO OUR SOUTH AND
EAST DURING MONDAY, THEN AN EXPANSIVE AREA OF HIGH PRESSURE IS
SCHEDULED TO BUILD IN FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH THE MIDDAY UPDATE, WE ADDED SOME ISOLATED SHOWERS TO THE
FORECAST FOR THE NEXT COUPLE OF HOURS ACROSS PORTIONS OF FAR
SOUTHEASTERN PENNSYLVANIA, FAR NORTHERN DELAWARE, AND CECIL COUNTY
MARYLAND. LATEST RADAR IMAGERY SHOWS A SMALL AREA OF LIGHT SHOWERS
AND SPRINKLES HOLDING TOGETHER AND SLOWLY MOVING EAST INTO THESE
AREAS. IN ADDITION, HOURLY TEMPS AND DEWPOINTS WERE ALSO TWEAKED
THROUGH THE AFTERNOON USING THE LAV/LAMP GUIDANCE TO ACCOUNT FOR
LATEST OBSERVATIONS AND TRENDS.
OTHERWISE, THE MID-ATLANTIC IS LOCATED TOWARD THE BASE OF AN
UPPER TROUGH AS SEEN ON WATER VAPOR SATELLITE IMAGERY. THIS LARGE-
SCALE TROUGH IS ASSOCIATED WITH AN UPPER LOW LOCATED JUST TO THE
EAST OF HUDSON BAY. A COLD FRONT STRETCHING FROM THE GULF OF ST
LAWRENCE SOUTHEASTWARD INTO UPSTATE NY WAS RATHER DIFFUSE ON THE
13Z SFC ANALYSIS. THE COLD FRONT WILL MOVE SOUTHWARD INTO THE MID-
ATLANTIC REGION THIS AFTERNOON.
12Z IAD, APG AND OKX SOUNDINGS ALL OBSERVED A SHALLOW SATURATED
LAYER BETWEEN 800-700 MB WITH MOISTURE TRAPPED BELOW THE MID-LEVEL
SUBSIDENCE INVERSION. MODEST LIFT ASSOCIATED WITH A SHORTWAVE TROUGH
HAS LEAD TO A BAND OF BKN-OVC STRATOCU OVER EASTERN PA, NORTHWEST NJ
AND THE EASTERN MD SO FAR THIS MORNING. TRIED TO TIME EASTWARD
PROGRESSION OF THE TROUGH AND ASSOCIATED STRATOCU IN HOURLY SKY
GRIDS WITH THE MORNING UPDATE. LATEST RAP MODEL, WHICH HAD
INITIALIZED WELL WITH CURRENT CLOUD COVER, HANGS ON TO THE MORNING
CLOUD THE LONGEST INTO THE AFTERNOON OVER SOUTHEASTERN PA AND THE
DELMARVA.
FORECAST MAX TEMPS TODAY IN THE MID 70S ARE ONLY A COUPLE OF DEGREES
BELOW CLIMO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE MID-LEVEL TROF AXIS MOVES OFF THE COAST THIS EVENING. A SURFACE
HIGH BEHIND THE COLD FRONT BEGINS TO BUILD IN ACROSS THE AREA.
TEMPERATURES WILL SETTLE IN THE LOWER 40S ACROSS THE SOUTHERN
POCONOS TO THE MID 50S ACROSS THE COASTAL PLAIN. THIS IS A FEW
DEGREES BELOW NORMAL.
COULD BE A BIT MORE CLOUDINESS ACROSS THE SOUTHERN ZONES, BUT NO
PRECIPITATION IS EXPECTED. SOME PATCHY FOG IS POSSIBLE TOWARD
MORNING.
NORTHWEST WINDS ON THE LIGHTER SIDE WILL SHIFT OUT OF THE NORTH OR
NORTHEAST BY THE FRIDAY SUNRISE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF THE FLOW BECOMING MORE
ZONAL FRIDAY ACROSS THE NORTHERN HALF OF THE NATION. SOME RIDGE
DEVELOPMENT THOUGH OUT WEST LOOKS TO ALLOW A SHORT WAVE TO DIVE INTO
THE MIDWEST SATURDAY, WHICH RESULTS IN A TROUGH AMPLIFYING ACROSS
THE GREAT LAKES AND NORTHEAST SUNDAY THROUGH MONDAY. THIS TROUGH MAY
THEN START TO LIFT OUT LATE TUESDAY. IT APPEARS THE MAIN FRONTAL
PASSAGE OCCURS SUNDAY NIGHT INTO MONDAY, THEN AN EXPANSIVE SURFACE
HIGH IS SCHEDULED TO BUILD ACROSS THE REGION TUESDAY AND WEDNESDAY.
WE USED A GENERAL MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN
BLENDED IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE
THEN MADE AFTER ADDITIONAL COLLABORATION WITH OUR SURROUNDING
OFFICES.
FOR FRIDAY...STRONG SURFACE HIGH PRESSURE SHOULD BE SHIFTING OFF THE
NEW ENGLAND COAST WITH OUR LOW-LEVEL FLOW TURNING EAST AND
SOUTHEAST. THERE IS SOME MOISTURE FORECAST TO BE LINGERING WELL
OFFSHORE ESPECIALLY TO OUR SOUTHEAST, AND THE ONSHORE FLOW INTO OUR
AREA MAY RESULT IN SOME CLOUDINESS ESPECIALLY AT NIGHT. THE
POTENTIAL COMPLICATION IS THAT THE LOW-LEVEL FLOW MAY ACTUALLY VEER
TO MORE SOUTHEAST OR SOUTH THROUGH FRIDAY NIGHT, FOCUSING AN
INCREASE IN MOISTURE NORTHWEST OF THE FALL LINE. IT IS HERE WHERE
PERHAPS SOME STRATUS AND/OR FOG DEVELOPS AS THE LOW-LEVEL MOISTURE
POOLS BENEATH AN INVERSION. AS OF NOW, NOT QUITE SURE HOW MUCH
STRATUS DEVELOPS DUE TO SOME QUESTION ON HOW QUICK THE LOWER LEVELS
MOISTEN UP. FOR NOW, WE INCREASED THE CLOUDS ESPECIALLY AT NIGHT A
BIT MORE. THE COMBINATION OF A NEW AIRMASS AND THE ONSHORE FLOW
SHOULD RESULT IN A COOL DAY ACROSS THE CWA, AND POTENTIALLY BREEZY
ALONG THE COAST.
FOR SATURDAY AND SUNDAY...HIGH PRESSURE BECOMES ELONGATED INTO THE
MID ATLANTIC AS IT WEAKENS AND SHIFTS FARTHER OFFSHORE. THIS OCCURS
AS SOME WAA GETS UNDERWAY AHEAD OF THE NEXT SYSTEM AND HEIGHTS RISE
SOME. THIS SHOULD RESULT IN A NORTHBOUND WARM FRONT THAT MOSTLY
SLIDES JUST TO OUR NORTHWEST, AND WARMER AIR ARRIVES ACROSS OUR CWA
ESPECIALLY SUNDAY WITH A MORE SOUTHWESTERLY LOW-LEVEL FLOW. A SHORT
WAVE DIVING ACROSS THE GREAT LAKES WILL DRIVE A SURFACE LOW
EASTWARD. THE AMPLIFICATION OF THE UPPER-LEVEL TROUGH SHOULD TAKE
THE MAIN SURFACE LOW WELL TO OUR NORTH THOUGH DURING SUNDAY. THE
ASSOCIATED COLD FRONT HOWEVER WILL ARRIVE INTO OUR AREA LATE SUNDAY
WITH SOME SHOWERS. A BAND OF SHOWERS MAY END UP WEAKENING WITH A
SOUTHEASTERN EXTENT DUE TO MUCH OF THE LARGE SCALE LIFT PEELING
AWAY TO THE NORTH. THE INSTABILITY LOOKS LOW THEREFORE WE
CONTINUED WITH NO THUNDER MENTION ATTM. WE GENERALLY FAVORED A
BLEND OF CONTINUITY AND WPC GUIDANCE, WHICH PAINTS SLIGHT CHC TO
LOW CHC POPS ACROSS THE CWA MAINLY SUNDAY NIGHT. MEANWHILE, A LEAD
SHORT WAVE NEAR THE CAROLINAS MAY ORGANIZE A SURFACE LOW ALONG AN
OLD BAROCLINIC ZONE. THIS FEATURE SHOULD TRACK NORTHEAST AND HAVE
NO REAL AFFECT ON OUR SENSIBLE WEATHER.
FOR MONDAY AND TUESDAY...THE MAIN UPPER-LEVEL TROUGH MAY AMPLIFY
SOME MORE ACROSS THE NORTHEAST AND MID ATLANTIC REGIONS MONDAY.
BASED ON SOME RIDGING ENTERING THE PLAINS, AN EXPANSIVE SURFACE HIGH
IS FORECAST TO BUILD ACROSS THE MIDWEST AND GREAT LAKES LATER MONDAY
INTO TUESDAY, WITH THIS FEATURE ARRIVING INTO OUR AREA DURING
TUESDAY. SOME GUIDANCE SHOWS SOME INSTABILITY TYPE SHOWERS OCCURRING
JUST TO OUR NORTH TUESDAY AS ANOTHER SHORT WAVE ROTATES AROUND THE
BASE OF THE UPPER-LEVEL TROUGH. REGARDING POPS, KEPT SOME SLIGHT CHC
TO LOW CHC POPS ESPECIALLY MONDAY MORNING WITH THE DEPARTING COLD
FRONT. WE CARRIED A DRY FORECAST FOR TUESDAY AS THE UPPER-LEVEL
TROUGH MAY START TO LIFT OUT SOME WITH ANY FOCUS GENERALLY TO OUR
NORTH.
FOR WEDNESDAY...AS A RIDGE SLIDES ACROSS THE GREAT LAKES, A
POTENTIALLY STRONG SURFACE HIGH BUILDS ACROSS THE NORTHEAST AND MID
ATLANTIC REGIONS. IF THE CENTER OF THIS HIGH ENDS UP ACROSS NEW
ENGLAND, THEN WE WILL HAVE AN ONSHORE FLOW ONCE AGAIN. AS OF NOW,
LEANED MUCH CLOSER TO THE 00Z WPC GUIDANCE FOR ALL WEATHER ELEMENTS.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS
VFR TDA AND TNGT. STRATOCU BETWEEN 5-9 KFT PROGRESSES EASTWARD
ACROSS THE TERMINALS TDA. NW WINDS UNDER 10 KT TODAY WILL VEER TO
THE N THIS EVE AND NE BY EARLY FRI MRNG.
OUTLOOK...
FRIDAY...VFR THROUGH THE DAY, HOWEVER SOME LOW CLOUDS OR EVEN SOME
FOG COULD DEVELOP OVERNIGHT WITHIN AN ONSHORE FLOW. OUR CONFIDENCE
IS ON THE LOWER SIDE.
SATURDAY AND SUNDAY...SOME LOW CLOUDS AND/OR SOME FOG TO START EACH
DAY, OTHERWISE MOSTLY VFR. A COLD FRONT ARRIVES SUNDAY NIGHT WITH
POSSIBLE SHOWERS AND LOCAL SUB-VFR CONDITIONS.
MONDAY...SOME SHOWERS POSSIBLE ESPECIALLY IN THE MORNING, OTHERWISE
MOSTLY VFR WITH A WIND SHIFT TO THE NORTHWEST.
&&
.MARINE...
BUOY 44065 CAME BACK ON LINE ABOUT 10 PM LAST NIGHT. HOPEFULLY BUOY
44025 WILL NOT BE FAR BEHIND.
TODAY...LONG PERIOD SWELLS GENERATED BY EDOUARD CONTINUE TO REACH
THE EAST COAST TODAY. LATEST OBS SHOW 13-14 SEC WAVE PERIODS THIS
MORNING. SEAS EXPECTED TO REMAIN JUST BELOW SCA LEVELS WIT WAVE
HEIGHTS ARE 4 FT WHILE NORTHERLY WINDS WILL BE AROUND 10 KT
(GUSTING TO 20 KT LATE IN THE DAY).
TONIGHT...SWELLS ARE STILL FORECAST TO BE WITH US THROUGH TONIGHT.
SEAS WILL BE LESS THAN 4 FEET. LIGHT NORTHERLY WINDS WILL INCREASE
TO 20 KT OVERNIGHT ESPECIALLY ACROSS THE NORTHERN WATERS.
OUTLOOK...
FRIDAY...A NORTHEASTERLY WIND SURGE WITH AN INITIAL TIGHTENING OF
THE PRESSURE GRADIENT AND CAA SHOULD THEN EASE SOME AS THE WINDS
TURN EAST-SOUTHEAST BY LATE IN THE DAY AND AT NIGHT. THE SURGE COULD
BE ENOUGH FOR SOME 25-KNOT GUSTS AND SEAS BUILDING TO 5 FEET ON THE
COASTAL WATERS FOR A TIME. AS OF NOW THE WINDS AND SEAS ARE
MARGINAL AND THEREFORE WILL HOLD OFF ON AN ADVISORY.
SATURDAY AND SUNDAY...THE WINDS SHOULD TURN FROM THE SOUTH DURING
THIS TIME FRAME AS HIGH PRESSURE DEPARTS TO THE EAST. THE NEXT COLD
FRONT ARRIVES SUNDAY NIGHT, HOWEVER AN INCREASE IN THE WINDS SHOULD
OCCUR AHEAD OF IT BUT THEY SHOULD BE BELOW ADVISORY CRITERIA. THE
SEAS HOWEVER COULD BE RIGHT NEAR 5 FEET SATURDAY FROM THE EARLIER
ONSHORE COMPONENT.
MONDAY...THE CONDITIONS SHOULD BE BELOW ADVISORY CRITERIA OVERALL AS
WINDS SHIFT FROM THE NORTH AS HIGH PRESSURE STARTS TO BUILD IN LATE.
&&
.RIP CURRENTS...
IN HOUSE GUIDANCE SUGGESTS A MODERATE RISK TODAY FOR NJ/DE BECAUSE OF
LONG PERIOD SWELLS GENERATED BY EDOUARD.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...KLEIN/KLINE
SHORT TERM...KRUZDLO
LONG TERM...GORSE
AVIATION...GORSE/KLEIN/KRUZDLO
MARINE...GORSE/KLEIN/KRUZDLO
RIP CURRENTS...KRUZDLO/KLEIN
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
930 AM EDT THU SEP 18 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE THROUGH OUR AREA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL THEN BUILD IN TONIGHT INTO FRIDAY,
BEFORE SHIFTING OFFSHORE FRIDAY NIGHT. A WARM FRONT WILL LIFT TO
OUR NORTHWEST SATURDAY, THEN A COLD FRONT IS EXPECTED TO ARRIVE
LATE SUNDAY INTO MONDAY. THIS FRONT WILL SETTLE TO OUR SOUTH AND
EAST DURING MONDAY, THEN AN EXPANSIVE AREA OF HIGH PRESSURE IS
SCHEDULED TO BUILD IN FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE MID-ATLANTIC IS LOCATED TOWARD THE BASE OF AN UPPER TROUGH AS
SEEN ON WATER VAPOR SATELLITE IMAGERY THIS MORNING. THIS LARGE-SCALE
TROUGH IS ASSOCIATED WITH AN UPPER LOW LOCATED JUST TO THE EAST OF
HUDSON BAY. A COLD FRONT STRETCHING FROM THE GULF OF ST LAWRENCE
SOUTHEASTWARD INTO UPSTATE NY WAS RATHER DIFFUSE ON THE 13Z SFC
ANALYSIS. THE COLD FRONT WILL MOVE SOUTHWARD INTO THE MID-ATLANTIC
REGION THIS AFTERNOON.
12Z IAD, APG AND OKX SOUNDINGS ALL OBSERVED A SHALLOW SATURATED
LAYER BETWEEN 800-700 MB WITH MOISTURE TRAPPED BELOW THE MID-LEVEL
SUBSIDENCE INVERSION. MODEST LIFT ASSOCIATED WITH A SHORTWAVE TROUGH
HAS LEAD TO A BAND OF BKN-OVC STRATOCU OVER EASTERN PA, NORTHWEST NJ
AND THE EASTERN MD SO FAR THIS MORNING. TRIED TO TIME EASTWARD
PROGRESSION OF THE TROUGH AND ASSOCIATED STRATOCU IN HOURLY SKY
GRIDS WITH THE MORNING UPDATE. LATEST RAP MODEL, WHICH HAD
INITIALIZED WELL WITH CURRENT CLOUD COVER, HANGS ON TO THE MORNING
CLOUD THE LONGEST INTO THE AFTERNOON OVER SOUTHEASTERN PA AND THE
DELMARVA.
FORECAST MAX TEMPS TODAY IN THE MID 70S ARE ONLY A COUPLE OF DEGREES
BELOW CLIMO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE MID-LEVEL TROF AXIS MOVES OFF THE COAST THIS EVENING. A SURFACE
HIGH BEHIND THE COLD FRONT BEGINS TO BUILD IN ACROSS THE AREA.
TEMPERATURES WILL SETTLE IN THE LOWER 40S ACROSS THE SOUTHERN
POCONOS TO THE MID 50S ACROSS THE COASTAL PLAIN. THIS IS A FEW
DEGREES BELOW NORMAL.
COULD BE A BIT MORE CLOUDINESS ACROSS THE SOUTHERN ZONES, BUT NO
PRECIPITATION IS EXPECTED. SOME PATCHY FOG IS POSSIBLE TOWARD
MORNING.
NORTHWEST WINDS ON THE LIGHTER SIDE WILL SHIFT OUT OF THE NORTH OR
NORTHEAST BY THE FRIDAY SUNRISE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF THE FLOW BECOMING MORE
ZONAL FRIDAY ACROSS THE NORTHERN HALF OF THE NATION. SOME RIDGE
DEVELOPMENT THOUGH OUT WEST LOOKS TO ALLOW A SHORT WAVE TO DIVE INTO
THE MIDWEST SATURDAY, WHICH RESULTS IN A TROUGH AMPLIFYING ACROSS
THE GREAT LAKES AND NORTHEAST SUNDAY THROUGH MONDAY. THIS TROUGH MAY
THEN START TO LIFT OUT LATE TUESDAY. IT APPEARS THE MAIN FRONTAL
PASSAGE OCCURS SUNDAY NIGHT INTO MONDAY, THEN AN EXPANSIVE SURFACE
HIGH IS SCHEDULED TO BUILD ACROSS THE REGION TUESDAY AND WEDNESDAY.
WE USED A GENERAL MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN
BLENDED IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE
THEN MADE AFTER ADDITIONAL COLLABORATION WITH OUR SURROUNDING
OFFICES.
FOR FRIDAY...STRONG SURFACE HIGH PRESSURE SHOULD BE SHIFTING OFF THE
NEW ENGLAND COAST WITH OUR LOW-LEVEL FLOW TURNING EAST AND
SOUTHEAST. THERE IS SOME MOISTURE FORECAST TO BE LINGERING WELL
OFFSHORE ESPECIALLY TO OUR SOUTHEAST, AND THE ONSHORE FLOW INTO OUR
AREA MAY RESULT IN SOME CLOUDINESS ESPECIALLY AT NIGHT. THE
POTENTIAL COMPLICATION IS THAT THE LOW-LEVEL FLOW MAY ACTUALLY VEER
TO MORE SOUTHEAST OR SOUTH THROUGH FRIDAY NIGHT, FOCUSING AN
INCREASE IN MOISTURE NORTHWEST OF THE FALL LINE. IT IS HERE WHERE
PERHAPS SOME STRATUS AND/OR FOG DEVELOPS AS THE LOW-LEVEL MOISTURE
POOLS BENEATH AN INVERSION. AS OF NOW, NOT QUITE SURE HOW MUCH
STRATUS DEVELOPS DUE TO SOME QUESTION ON HOW QUICK THE LOWER LEVELS
MOISTEN UP. FOR NOW, WE INCREASED THE CLOUDS ESPECIALLY AT NIGHT A
BIT MORE. THE COMBINATION OF A NEW AIRMASS AND THE ONSHORE FLOW
SHOULD RESULT IN A COOL DAY ACROSS THE CWA, AND POTENTIALLY BREEZY
ALONG THE COAST.
FOR SATURDAY AND SUNDAY...HIGH PRESSURE BECOMES ELONGATED INTO THE
MID ATLANTIC AS IT WEAKENS AND SHIFTS FARTHER OFFSHORE. THIS OCCURS
AS SOME WAA GETS UNDERWAY AHEAD OF THE NEXT SYSTEM AND HEIGHTS RISE
SOME. THIS SHOULD RESULT IN A NORTHBOUND WARM FRONT THAT MOSTLY
SLIDES JUST TO OUR NORTHWEST, AND WARMER AIR ARRIVES ACROSS OUR CWA
ESPECIALLY SUNDAY WITH A MORE SOUTHWESTERLY LOW-LEVEL FLOW. A SHORT
WAVE DIVING ACROSS THE GREAT LAKES WILL DRIVE A SURFACE LOW
EASTWARD. THE AMPLIFICATION OF THE UPPER-LEVEL TROUGH SHOULD TAKE
THE MAIN SURFACE LOW WELL TO OUR NORTH THOUGH DURING SUNDAY. THE
ASSOCIATED COLD FRONT HOWEVER WILL ARRIVE INTO OUR AREA LATE SUNDAY
WITH SOME SHOWERS. A BAND OF SHOWERS MAY END UP WEAKENING WITH A
SOUTHEASTERN EXTENT DUE TO MUCH OF THE LARGE SCALE LIFT PEELING
AWAY TO THE NORTH. THE INSTABILITY LOOKS LOW THEREFORE WE
CONTINUED WITH NO THUNDER MENTION ATTM. WE GENERALLY FAVORED A
BLEND OF CONTINUITY AND WPC GUIDANCE, WHICH PAINTS SLIGHT CHC TO
LOW CHC POPS ACROSS THE CWA MAINLY SUNDAY NIGHT. MEANWHILE, A LEAD
SHORT WAVE NEAR THE CAROLINAS MAY ORGANIZE A SURFACE LOW ALONG AN
OLD BAROCLINIC ZONE. THIS FEATURE SHOULD TRACK NORTHEAST AND HAVE
NO REAL AFFECT ON OUR SENSIBLE WEATHER.
FOR MONDAY AND TUESDAY...THE MAIN UPPER-LEVEL TROUGH MAY AMPLIFY
SOME MORE ACROSS THE NORTHEAST AND MID ATLANTIC REGIONS MONDAY.
BASED ON SOME RIDGING ENTERING THE PLAINS, AN EXPANSIVE SURFACE HIGH
IS FORECAST TO BUILD ACROSS THE MIDWEST AND GREAT LAKES LATER MONDAY
INTO TUESDAY, WITH THIS FEATURE ARRIVING INTO OUR AREA DURING
TUESDAY. SOME GUIDANCE SHOWS SOME INSTABILITY TYPE SHOWERS OCCURRING
JUST TO OUR NORTH TUESDAY AS ANOTHER SHORT WAVE ROTATES AROUND THE
BASE OF THE UPPER-LEVEL TROUGH. REGARDING POPS, KEPT SOME SLIGHT CHC
TO LOW CHC POPS ESPECIALLY MONDAY MORNING WITH THE DEPARTING COLD
FRONT. WE CARRIED A DRY FORECAST FOR TUESDAY AS THE UPPER-LEVEL
TROUGH MAY START TO LIFT OUT SOME WITH ANY FOCUS GENERALLY TO OUR
NORTH.
FOR WEDNESDAY...AS A RIDGE SLIDES ACROSS THE GREAT LAKES, A
POTENTIALLY STRONG SURFACE HIGH BUILDS ACROSS THE NORTHEAST AND MID
ATLANTIC REGIONS. IF THE CENTER OF THIS HIGH ENDS UP ACROSS NEW
ENGLAND, THEN WE WILL HAVE AN ONSHORE FLOW ONCE AGAIN. AS OF NOW,
LEANED MUCH CLOSER TO THE 00Z WPC GUIDANCE FOR ALL WEATHER ELEMENTS.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS
VFR TDA AND TNGT. STRATOCU BETWEEN 5-9 KFT PROGRESSES EASTWARD
ACROSS THE TERMINALS TDA. NW WINDS UNDER 10 KT TODAY WILL VEER TO
THE N THIS EVE AND NE BY EARLY FRI MRNG.
OUTLOOK...
FRIDAY...VFR THROUGH THE DAY, HOWEVER SOME LOW CLOUDS OR EVEN SOME
FOG COULD DEVELOP OVERNIGHT WITHIN AN ONSHORE FLOW. OUR CONFIDENCE
IS ON THE LOWER SIDE.
SATURDAY AND SUNDAY...SOME LOW CLOUDS AND/OR SOME FOG TO START EACH
DAY, OTHERWISE MOSTLY VFR. A COLD FRONT ARRIVES SUNDAY NIGHT WITH
POSSIBLE SHOWERS AND LOCAL SUB-VFR CONDITIONS.
MONDAY...SOME SHOWERS POSSIBLE ESPECIALLY IN THE MORNING, OTHERWISE
MOSTLY VFR WITH A WIND SHIFT TO THE NORTHWEST.
&&
.MARINE...
BUOY 44065 CAME BACK ON LINE ABOUT 10 PM LAST NIGHT. HOPEFULLY BUOY
44025 WILL NOT BE FAR BEHIND.
TODAY...LONG PERIOD SWELLS GENERATED BY EDOUARD CONTINUE TO REACH
THE EAST COAST TODAY. LATEST OBS SHOW 13-14 SEC WAVE PERIODS THIS
MORNING. SEAS EXPECTED TO REMAIN JUST BELOW SCA LEVELS WIT WAVE
HEIGHTS ARE 4 FT WHILE NORTHERLY WINDS WILL BE AROUND 10 KT
(GUSTING TO 20 KT LATE IN THE DAY).
TONIGHT...SWELLS ARE STILL FORECAST TO BE WITH US THROUGH TONIGHT.
SEAS WILL BE LESS THAN 4 FEET. LIGHT NORTHERLY WINDS WILL INCREASE
TO 20 KT OVERNIGHT ESPECIALLY ACROSS THE NORTHERN WATERS.
OUTLOOK...
FRIDAY...A NORTHEASTERLY WIND SURGE WITH AN INITIAL TIGHTENING OF
THE PRESSURE GRADIENT AND CAA SHOULD THEN EASE SOME AS THE WINDS
TURN EAST-SOUTHEAST BY LATE IN THE DAY AND AT NIGHT. THE SURGE COULD
BE ENOUGH FOR SOME 25-KNOT GUSTS AND SEAS BUILDING TO 5 FEET ON THE
COASTAL WATERS FOR A TIME. AS OF NOW THE WINDS AND SEAS ARE
MARGINAL AND THEREFORE WILL HOLD OFF ON AN ADVISORY.
SATURDAY AND SUNDAY...THE WINDS SHOULD TURN FROM THE SOUTH DURING
THIS TIME FRAME AS HIGH PRESSURE DEPARTS TO THE EAST. THE NEXT COLD
FRONT ARRIVES SUNDAY NIGHT, HOWEVER AN INCREASE IN THE WINDS SHOULD
OCCUR AHEAD OF IT BUT THEY SHOULD BE BELOW ADVISORY CRITERIA. THE
SEAS HOWEVER COULD BE RIGHT NEAR 5 FEET SATURDAY FROM THE EARLIER
ONSHORE COMPONENT.
MONDAY...THE CONDITIONS SHOULD BE BELOW ADVISORY CRITERIA OVERALL AS
WINDS SHIFT FROM THE NORTH AS HIGH PRESSURE STARTS TO BUILD IN LATE.
&&
.RIP CURRENTS...
IN HOUSE GUIDANCE SUGGESTS A MODERATE RISK TODAY FOR NJ/DE BECAUSE OF
LONG PERIOD SWELLS GENERATED BY EDOUARD.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...KLEIN
SHORT TERM...KRUZDLO
LONG TERM...GORSE
AVIATION...GORSE/KLEIN
MARINE...GORSE/KLEIN/KRUZDLO
RIP CURRENTS...KRUZDLO/KLEIN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
11 AM EDT THU SEP 18 2014
.DISCUSSION...
PATCHY LOW CLOUDS LINGERING FROM VERO BEACH AND FORT PIERCE WEST TO
THE KISSIMMEE RIVER WILL LIFT BY NOON. MORNING CAPE SOUNDING SHOWS
MUCH DRIER AIR ABOVE 850 MB BUT SUFFICIENT LOW LEVEL MOISTURE
REMAINS SO EXPECT SCATTERED CU TO DEVELOP. HAVE ADJUSTED POPS JUST A
LITTLE...REDUCING RAIN CHANCES ALONG THE TREASURE COAST TO 20
PERCENT IN ORDER TO SHOW THAT THE BEST CHANCE FOR SHOWERS THIS AFTN
WILL BE OVER THE INTERIOR AND AROUND LAKE OKEECHOBEE. LIGHT N/NW
WINDS THIS MORNING WILL TURN NE TO EAST THIS AFTERNOON. OUR LOCAL
WRF AND THE HRRR MODEL ARE IN GOOD AGREEMENT REGARDING EXPECTED
EVOLUTION OF CONVECTION THIS AFTERNOON SHOWING THE BEST CHANCE FOR
SHOWERS AND A FEW STORMS AROUND LAKE OKEECHOBEE AS WELL AS THE NORTH
INTERIOR. MOTION GENERALLY TOWARD THE S/SW.
PREVIOUS DAY 1 DISCUSSION...
LITTLE IN THE WAY OF ORGANIZED PRECIP TODAY AS THE RELATIVELY STABLE
AIRMASS OVERHEAD LIMITS VERTICAL MOTION...WHILE DRY AIR ALOFT LIMITS
POTENTIAL FOR CU DVLPMNT. BROAD LOW PRES OVER THE W ATLC WILL LIFT
NE...ALLOWING HI PRES TO BUILD DOWN THE ERN SEABOARD IN ITS WAKE. AS
IT DOES...LIGHT NWRLY WINDS THRU THE H100-H85 LYR WILL VEER TO THE
NE BY MIDDAY...THEN TO THE E THRU SUNSET.
NW/NE FLOW REGIMES TYPICALLY DO NOT PRODUCE MUCH IN THE WAY OF
THUNDER OVER CENTRAL FL. CANNOT COMPLETELY RULE OUT PRECIP WITH SFC
DEWPOINTS IN THE L70S AND H100-H70 MEAN RH VALUES RUINING BTWN
70-80PCT. HOWEVER...THE DLVPG ONSHORE FLOW WILL LIMIT THE WINDOW OF
OPPORTUNITY FOR COASTAL TSRA DVLPMNT. INTERIOR WILL HAVE A BETTER
OPPORTUNITY AS NEAR FULL SUN WILL ALLOW TEMPS TO REACH THEIR
CONVECTIVE TRIGGERS BY EARLY AFTN. HOWEVER...WITH PWAT VALUES
EXPECTED TO DROP TO ARND 1.6"...CHANCES WILL BE AOB 20PCT OVER MOST
OF THE AREA....WITH GO WITH 30 POPS ARND LAKE OKEECHOBEE DUE TO
SLIGHTLY HIGHER MOISTURE PROFILE. PRECIP SHOULD BURN OUT BY SUNSET
OR SHORTLY THEREAFTER.
DVLPG ONSHORE FLOW WILL KEEP MAX TEMPS ALONG THE COAST IN THE
M/U80S...INTERIOR WARMING INTO THE L90S. MIN TEMPS HOLDING IN THE
L/M70S AREAWIDE OVERNIGHT AS THE CONTINUING ONSHORE FLOW WILL
QUICKLY MODIFY WHATEVER LOW DEWPOINT AIR THAT MANAGES TO FILTER INTO
THE CWA.
&&
.AVIATION...
LINGERING MVFR CIGS AT VRB/FPR WILL LIFT BY 16Z. BRIEF MVFR CIGS
WILL BE POSSIBLE ELSEWHERE AS SFC HEATING WORKS ON LOW LEVEL
MOISTURE BUT ENTRAINMENT OF DRIER AIR ALOFT SHOULD LIMIT DURATION OF
MVFR CONDS. ISOLATED SHRA/TSRA AFT 17Z PUSHING SOUTHWARD MAY IMPACT
SFB/MCO/LEE. LIGHT N/NW FLOW TURNING NE TO EAST.
&&
.MARINE...
NO SIGNIFICANT CHANGES TO CURRENT COASTAL WATERS FORECAST.
WEAK HI PRES OVER NEW ENGLAND AND THE MID ATLC STATES WILL NUDGE ITS
WAY OFF THE ERN SEABOARD... ALLOWING SFC/BNDRY LYR WINDS OVER THE
LCL ATLC TO VEER TO THE N/NE BY MIDDAY...THEN TO THE E BY LATE
AFTN...STEADY SPEEDS BTWN 8-10KTS. LONG PD SWELLS FROM HURRICANE
EDOUARD WILL DAMPEN OVER THE LCL ATLC THRU THE DAY...SUBSIDING TO
2-3FT NEARSHORE AND 3-4FT OFFSHORE TODAY...THEN 2-3FT AREAWIDE
TONIGHT. ISOLD SHRAS LIMITED TO THE GULF STREAM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 87 74 83 71 / 20 10 60 40
MCO 91 73 87 69 / 20 20 60 50
MLB 87 75 84 73 / 20 10 70 50
VRB 86 73 85 73 / 20 10 70 50
LEE 91 74 88 68 / 20 20 60 40
SFB 91 74 86 70 / 20 20 60 40
ORL 91 74 86 69 / 20 20 60 50
FPR 87 73 86 73 / 30 10 70 50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
KELLY/VOLKMER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
400 AM EDT THU SEP 18 2014
...NUMEROUS SHOWERS RETURN TO THE FORECAST FOR FRIDAY...
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A LONGWAVE PATTERN
CONSISTING OF RIDGING OVER MUCH OF THE INTER-MOUNTAIN WEST AND
DOWNSTREAM TROUGHING INTO THE EASTERN STATES. FLORIDA PENINSULA
RESIDES ON THE SOUTHERN PERIPHERY OF THE EASTERN CONUS TROUGH.
IMPULSES ARE MOVING FAIRLY QUICKLY THROUGH THIS PATTERN AND SO THE
FORECAST WILL BE CHANGING QUICKLY AS WELL THROUGH THE NEXT 24 TO 36
HOURS. SHORTWAVE IMPULSE IS NOW PULLING EAST OF THE REGION WITH A
SWATH OF LARGE SCALE SUBSIDENCE AND RESULTING DRY AIR ALOFT NOW
PROGRESSING OVER THE NORTHERN AND CENTRAL PORTIONS OF THE PENINSULA.
THIS MORE SUPPRESSIVE ENVIRONMENT ALLOWED MUCH OF THE REGION TO DRY
OUT DURING THE SECOND HALF OF WEDNESDAY AND CONTINUE TO SEE MAINLY
DRY CONDITIONS EARLY THIS MORNING. ONLY SHOWERS ARE OCCURRING OVER
THE FAR SOUTHERN ZONES/COASTAL WATERS WITHIN A MORE FAVORABLE
MOISTURE COLUMN AND ALONG THE LEFTOVER FRONT/SURFACE TROUGH NOW DOWN
OVER FAR SOUTHERN FL.
AS MENTIONED ABOVE...WITH THE DRIER AIR ALOFT NOW FIRMLY IN PLACE...
SKIES HAVE BECOME MOSTLY CLEAR FOR ALL BUT THE FAR SOUTHERN AREAS
AROUND KFMY. PLENTY OF GROUND MOISTURE FROM THE RAIN ON WEDNESDAY
ALONG WITH A LITTLE SUPPRESSION IS ALLOWING SOME PATCHY GROUND FOG
EARLY THIS MORNING. NOT EXPECTED A WIDESPREAD EVENT...BUT A FEW MORE
FOG PRONE SPOTS MAY BRIEFLY SEE LOWERED VISIBILITIES BEFORE SUNRISE.
&&
.SHORT TERM (TODAY THROUGH FRIDAY)...
WELL...IT CERTAINLY LOOKS AS THOUGH TODAY WILL BE THE BETTER OF THE
TWO SHORT TERM DAYS IN TERMS OF SENSIBLE WEATHER...AS NUMEROUS
SHOWERS RETURN TO THE FORECAST FOR MUCH OF THE AREA FOR FRIDAY.
STARTING OUT THE DAY HERE IN WEST-CENTRAL FLORIDA ON THE BACKSIDE OF
DEPARTING UPPER LEVEL ENERGY...WITH A SWATH OF DRY AIR AND
SUPPRESSION IN PLACE. THIS PATTERN SHOULD KEEP OUR WEATHER MOSTLY
DRY / RAIN FREE THIS MORNING. ONLY EXCEPTION WILL CONTINUE TO BE
DOWN TOWARD LEE/CHARLOTTE COUNTIES WHERE A FEW SHOWERS WILL REMAIN
POSSIBLE...ESPECIALLY CLOSE TO THE COAST. TEMPERATURES WILL RISE
FROM THE UPPER 60S AND 70S AROUND SUNRISE THROUGH THE 80S DURING THE
MORNING.
THIS AFTERNOON...AS A RESULT OF THE LIGHT GRADIENT AND TERRESTRIAL
WARMING...SHOULD SEE A SEA-BREEZE CIRCULATION DEVELOP ON BOTH COASTS
OF THE PENINSULA AND MOVE INLAND. COMING TO THE END OF THE SUMMER
CONVECTION SEASON...BUT LOOKS AS THROUGH THE SEA-BREEZE TODAY WILL
FIND A GOOD ENOUGH ENVIRONMENT TO SUPPORT A FEW SCT STORMS BY THE
LATER AFTERNOON/EARLY EVENING HOURS. THIS SHOULD ESPECIALLY BE TRUE
OVER THE SOUTHERN ZONES AND AWAY FROM THE BEACHES. WOULD BE A BIT
CONCERNED ABOUT WHETHER CONVECTION COULD BE SUSTAINED IF THE CURRENT
UPPER LEVEL ENVIRONMENT WAS GOING TO LAST...BUT LOOKS AS THOUGH WE
WILL BEGIN TO SEE THE COLUMN MOISTEN BY LATER TODAY. AFTERNOON HIGH
TEMPERATURES SHOULD REACH WITHIN A COUPLE DEGREES EITHER SIDE OF 90.
TONIGHT WILL SEE OUR NEXT "WEATHER MAKER" BEGINNING TO APPROACH FROM
THE WEST IN THE FORM OF A DECENT SHORTWAVE TROUGH DIGGING DOWN THE
BACKSIDE OF THE MAIN LONGWAVE TROUGH...AND SPREADING OUR ACROSS THE
NORTHEAST GULF OF MEXICO. AHEAD OF THIS SHORTWAVE...GFS/ECMWF SHOW A
DECENT SWATH OF DEEP LAYER SYNOPTIC SUPPORT / Q-VECTOR CONVERGENCE
OVER THE EASTERN GULF OF MEXICO. IN ADDITION...THE REGION WILL COME
INCREASINGLY UNDER AN AREA OF UPPER LEVEL DIFFLUENCE WITHIN THE
ENTRANCE REGION OF JET ENERGY ALONG THE SHORTWAVE HEIGHT GRADIENT.
THEREFORE...FOR THIS TIME OF YEAR...WE LOOK TO HAVE HEALTHY SYNOPTIC
SUPPORT FOR LIFT. THIS LIFT WILL BE ALIGNED OVER A REGION OF LOWER
LEVEL FOCUS /CONVERGENCE ASSOCIATED WITH THE SURFACE REFLECTION OF
THE ENERGY PASSING ALOFT. WITH ALL THIS IN MIND...SEE LITTLE REASON
WHY NUMEROUS SHOWERS/STORMS WILL NOT BE BREAKING OUT OVER THE
EASTERN GULF DURING THE SECOND HALF OF THE NIGHT AND PROGRESSION
TOWARD THE FL WEST COAST. WILL KEEP THE HIGHEST RAIN CHANCES OFF THE
COAST DURING THE OVERNIGHT...BU DO NOT THINK IT WILL TAKE LONG AFTER
SUNRISE TO SEE THE SHOWERS COMING ASHORE (IF IT WAITS THAT LONG).
FRIDAY IS LOOKING LIKE AN UNSETTLED AND MOSTLY CLOUDY DAY WITH
PLENTY OF SHOWER ACTIVITY. WILL NOT BE RAINING THE WHOLE DAY...BUT
OUTDOOR ACTIVITIES LOOK TO ALMOST CERTAINLY BE IMPACTED. THE SWATH
OF Q-VECTOR CONVERGENCE AND UPPER LEVEL DIFFLUENCE ARRIVE OVER THE
PENINSULA AS THE UPPER LEVEL SHORTWAVE ENERGY AMPLIFIES OVER THE
EASTERN GULF. HAVE RAIN CHANCES QUICKLY INCREASING DURING THE
MORNING HOURS AND REACHING CATEGORICAL LEVELS FOR THE SECOND HALF OF
THE DAY. BEST MOISTURE/SYNOPTIC SUPPORT WILL ALIGN OVER THE CENTRAL
AND SOUTHERN PORTIONS OF THE AREA...HOWEVER...FEEL THE GUIDANCE IS
UNDERDONE OVER THE NATURE COAST...AND HAVE ALLOWED LIKELY POPS EVEN
FOR THESE ZONES. JUST CAN NOT SEE WITH THE ENERGY ALOFT...AND THE
TIME OF YEAR...THAT WE WILL NOT SUPPORT NUMEROUS SHOWERS TO THE
NORTH OF THE I-4 CORRIDOR. WITH ALL THE CLOUDS AND
SHOWERS...TEMPERATURES SHOULD BE HELD DOWN IN THE 80S. IF THE
SHOWERS ARE NUMEROUS ENOUGH AND START EARLY ENOUGH...THEN SOME SPOTS
MAY HAVE TROUBLE GETTING OUT OF THE LOWER 80S.
&&
.LONG TERM (SATURDAY THROUGH NEXT WEDNESDAY)...
THE PERIOD BEGINS WITH AN UPPER TROUGH OVER THE SOUTHEAST U.S. AND
EASTERN GULF WHILE HIGH PRESSURE OFFSHORE NEW ENGLAND SPRAWLS
SOUTHWARD TO THE GULF AND FL...WITH AN INVERTED TROUGH EAST OF THE
STATE. DURING THE WEEKEND A SHORT WAVE TROUGH SLIDES OUT OF CANADA
TO THE GREAT LAKES REGION...DEEPENING AS IT DOES...WITH THE UPPER
TROUGH BECOMING A BROAD CLOSED LOW OVER FL...SPINNING THE SURFACE
TOUGH INTO A LOW EAST OF THE GA/FL COAST. THESE TWO FEATURES TRACK
NORTHEASTWARD TOWARD THE END OF THE WEEKEND AS THE GREAT LAKES
TROUGH BEGINS TO DROP DOWN TO THE GULF COAST.
FOR THE EARLY PART OF NEXT WEEK THE GREAT LAKES-GULF COAST TROUGH
SLIDES OUT OVER ATLANTIC COASTAL WATERS AS DEEP LAYER RIDGING
BUILDS OVER THE MISSISSIPPI RIVER VALLEY THEN MOVES EAST...PUSHING
A FRONTAL BOUNDARY ACROSS THE GULF COASTAL AND SOUTHEASTERN STATES
AND INTO THE EAST GULF AND FL.
THE TROUGHINESS OVER THE WEEKEND FOLLOWED BY THE FRONTAL BOUNDARY
SAGGING IN WILL MAINTAIN A MOIST ATMOSPHERE WITH ISOLATED TO
SCATTERED SHOWERS AND STORMS. THERE WILL BE SOME MINOR VARIATION IN
TEMPERATURES BUT WITHIN A DEGREE OR TWO OF NORMAL.
&&
.AVIATION...
PATCHY FOG HAS DEVELOPED EARLY THIS MORNING ACROSS THE INTERIOR.
HAVE SEEN PROLONGED IFR OR LOWER VISIBILITIES AT KLAL AND THIS IS
LIKELY TO CONTINUE THROUGH SUNRISE. MAY SEE A BRIEF PERIOD OF VIS
RESTRICTIONS AROUND KPGD AS WELL TOWARD DAWN. ONCE ANY EARLY MORNING
FOG BURNS OFF WILL EXPECT PREVAILING VFR CONDITIONS FOR ALL
TERMINALS THROUGH THE DAY. WILL BE A FEW STORMS AROUND TODAY...WITH
THE BEST CHANCES FROM KPGD TO KFMY/KRSW. PREVAILING VFR CONDITIONS
SHOULD CONTINUE INTO THE EVENING HOURS AWAY FROM ANY SCT STORMS.
THEREAFTER...HEADING INTO FRIDAY...NUMEROUS SHOWERS/AREAS OF RAIN
LOOK TO BE IN THE FORECAST FOR ALL TERMINALS...AND LIKELY WILL BE
ACCOMPANIED BY PERIODS OF MVFR RESTRICTIONS.
&&
.MARINE...
A WEAK FRONT IS NOW STALLED SOUTH OF THE FORECAST WATERS WITH A VERY
WEAK GRADIENT IN PLACE OVER THE EASTERN GULF OF MEXICO. THIS WILL
RESULT IN LIGHT WINDS AND SEAS OVER THE WATERS THROUGH THIS EVENING.
WINDS BECOME EASTERLY ON FRIDAY AND MAY INCREASE TO NEAR CAUTIONARY
LEVELS AT TIMES FRIDAY AFTERNOON INTO EARLY SATURDAY...ESPECIALLY TO
THE NORTH OF ENGLEWOOD. IN ADDITION...SHOWERS AND STORMS LOOK TO
ONCE AGAIN BECOME NUMEROUS IN NATURE OVERNIGHT INTO FRIDAY.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE
UPCOMING WEEKEND. RAIN CHANCES WILL BE LOWER TODAY...BUT BECOME
LIKELY ONCE AGAIN FOR FRIDAY.
PATCHY GROUND FOG THIS MORNING WILL BURN OFF WITHIN A FEW HOURS OF
SUNRISE...AND IS NOT EXPECTED TO BE REPEATED TONIGHT INTO FRIDAY
MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 75 84 71 / 30 30 80 30
FMY 90 74 88 72 / 50 30 80 30
GIF 91 73 86 70 / 40 30 80 30
SRQ 89 73 87 71 / 30 30 80 30
BKV 91 71 84 67 / 30 20 70 30
SPG 89 77 84 73 / 30 30 80 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
416 AM EDT THU SEP 18 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF GEORGIA AND SOUTH CAROLINA INTO THE
WEEKEND. A COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...ISOLATED CONVECTION LINGERED ACROSS PARTS OF AREA THROUGH
1 AM BEFORE GATHERING OFFSHORE AND MOVING OUT INTO THE GULF STREAM.
LATEST EMC RAP ANALYSIS INDICATES INCREASING CIN AND NOT MUCH
RESIDUAL INSTABILITY LEFT THUS WE ARE EXPECTING MAINLY DRY WEATHER
FOR DAWN. AREAS OF STRATUS AND FOG WERE DEVELOPING INLAND AND SOME
SPOTS COULD SEE SOME LOCALLY DENSE FOG. AT THIS TIME...NO REGION
TO SINGLE OUT FOR VSBY PROBLEMS...ALTHOUGH SOUTH OF I-16 IN
GEORGIA WILL BE AN AREA TO WATCH.
MID AND UPPER LEVEL TROUGHING CONTINUES THROUGH TONIGHT ACROSS THE
SOUTHEASTERN SEABOARD WITH A POORLY DEFINED SURFACE FRONT CAMPING
OUT ALONG OR SOUTH OF THE SAVANNAH RIVER ENTRANCE. LOW CLOUDS AND
INLAND FOG SHOULD DISSIPATE AFTER MID MORNING WITH WEAK 850 MB
THETA-E ADVECTION FROM W TO E LIKELY TO GENERATE EXPANDING LATE
MORNING AND AFTERNOON CUMULUS/STRATOCU FIELDS. IN ADDITION...UPPER
JET STRUCTURE APT TO DEVELOP SOME HIGHER LEVEL CLOUDS AT TIMES.
CONVECTION PROGNOSIS TODAY POINTS TO AREAS MAINLY ALONG AND E OF I-95
IN SOUTH CAROLINA AS A WEAK LOW PRES REGION IN THE BOUNDARY LAYER
TAKES SHAPE ALONG THE SAVANNAH RIVER THIS AFTERNOON. A WEAK LOBE OF
MID LEVEL VORTICITY IS FORECAST TO TRAVERSE THE CAROLINAS WITH BETTER
THERMODYNAMICS AND MUCAPES PROGGED ALONG THE SEA BREEZE CORRIDOR
NORTH OF SAVANNAH. WHILE MODELS DO NOT SHOW QUITE AS MUCH OVERALL
INSTABILITY AS WEDNESDAY...A FEW STRONGER TSTMS WITH DOWNPOURS AND
FQT LIGHTNING ARE POSSIBLE. WE BUMPED POPS INTO THE CHANCE RANGE
ALONG AND E OF I-95 IN SOUTH CAROLINA THIS AFTERNOON AND ALONG THE
SE GEORGIA COASTAL ZONES EARLY THIS EVENING AS STORMS DRAIN DOWN THE
SEA BREEZE. INTERESTING TO NOTE THAT THE NSSL WRF HINTS AT SOME
DEVIANT/SPLITTING CELLS AGAIN TODAY...SIMILAR TO YESTERDAY. THE
00Z OPERATIONAL NAM APPEARED TO SUFFER FROM CONVECTIVE FEEDBACK AT
TIMES IN THROUGH TONIGHT.
HIGH TEMPS TODAY DEPENDENT ON HOW LONG THE SUN STAYS OUT MANY
AREAS AND WE BUMPED UP TEMPS CLOSER TO 90 SOUTH OF I-16 IN
GEORGIA.
TONIGHT...THERE COULD BE SOME LINGERING CONVECTION ONCE AGAIN WITH
BEACHES AND BARRIER ISLANDS SUSPECT AFTER MIDNIGHT. INLAND AREAS
MAY ALSO SEE YET ANOTHER BOUT OF LOW CLOUDS AND FOG.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...THE CENTER OF SURFACE HIGH PRESSURE WILL STEADILY TRACK
OVER THE NEW ENGLAND STATES DURING THE DAY...THEN OFF THE
NORTHERN COAST THROUGH THE EVENING AND NIGHTTIME PERIOD. THE
MOVEMENT OF THE HIGH WILL ALLOW AN INLAND WEDGE TO STRENGTHEN DOWN
THE APPALACHIANS...STRETCHING FROM THE MID ATLANTIC STATES
THROUGH THE CAROLINAS AND GEORGIA. THIS PATTERN WILL MAINTAIN
SOLID NORTHEAST FLOW ACROSS THE FORECAST AREA...WITH HIGH
TEMPERATURES REFLECTING THE ASSOCIATED COOLING TREND BY ONLY
PEAKING IN THE LOW TO MID 80S. MOISTURE AND CONVERGENCE ALONG THE
PERIPHERY OF THE INLAND WEDGE NEAR A DEVELOPING TROUGH...AS WELL
AS SHORTWAVE ENERGY EMBEDDED WITHIN THE WEAKENING UPPER
TROUGH...WILL STILL BE SUFFICIENT TO SUPPORT SCATTERED CONVECTION.
EXPECT INITIAL ACTIVITY TO BE FOUND OVER THE WATERS AND COASTLINE
DURING THE MORNING...EVENTUALLY SPREADING INLAND THROUGH THE
AFTERNOON HOURS WITHIN ONSHORE FLOW. BEST SHOWER/THUNDERSTORM
COVERAGE WILL THEN RETURN TO THE COASTLINE AFTER SUNSET. LOW
TEMPERATURES WILL CONTINUE TO TREND COOLER...FALLING INTO THE MID
60S INLAND AND UPPER 60S ALONG THE COAST.
SATURDAY...THE UPPER TROUGH ALONG THE EAST COAST WILL BE IN A
DAMPENING STATE LATE IN THE WEEK...EVENTUALLY TRANSITIONING INTO
A BAGGY UPPER LOW FEATURE AT THE START OF THE WEEKEND. ENERGY
WITHIN THIS LOW ALOFT WILL SUPPORT THE STRENGTHENING OF A COASTAL
TROUGH INTO A SURFACE WAVE OF LOW PRESSURE. THERE IS SOME
DISAGREEMENT BETWEEN MODEL SOLUTIONS REGARDING THE STRENGTH OF
THESE FEATURES...WITH CONSENSUS IN ITS GENERAL TRACK TO THE
NORTH/NORTHEAST OVER THE WATERS AS THE DAY PROGRESSES. INLAND
AREAS WITHIN THE WEDGE OF HIGH PRESSURE WILL REMAIN UNDER A DRIER
REGIME...AS THE BEST CHANCE FOR PRECIPITATION IS FOCUSED ACROSS
THE EASTERN HALF OF THE FORECAST AREA CLOSEST TO MOISTURE AND
CONVERGENCE OFFSHORE. HAVE THUS INDICATED SLIGHT CHANCE POPS FAR
INLAND...INCREASING TO 30 TO 40 PERCENT CLOSER TO THE COASTLINE.
RAIN COVERAGE WILL THEN TRANSITION BACK TO THE COASTLINE AND
MARINE ZONES OVERNIGHT. TEMPERATURES WILL BE EVEN COOLER ON
SATURDAY...AS AFTERNOON HIGHS ARE SUPPRESSED IN THE LOW 80S AND
NIGHTTIME MINIMUMS FALL INTO THE MID 60S.
SUNDAY...THE OFFSHORE SURFACE WAVE WILL CONTINUE TO LIFT
NORTH/NORTHEAST ACROSS THE ATLANTIC WATERS...AS THE WEAK UPPER
LOW BECOMES ABSORBED IN A DEEPENING TROUGH TO THE NORTH. THE
INLAND WEDGE WILL STEADILY BREAK DOWN THROUGH THE DAY AHEAD OF A
RAPIDLY APPROACHING COLD FRONT. THE FORECAST AREA COULD BECOME
LOCATED WITHIN A BAND OF DRY DEEP LAYER AIR BETWEEN THE OFFSHORE
LOW TO THE NORTHEAST AND THE COLD FRONT TO THE WEST. HAVE THUS
INDICATED ONLY A SLIGHT CHANCE FOR RAIN ALONG THE
COASTLINE...EXCEPT FOR A SMALL AREA OF CHANCE POPS SOUTH OF
INTERSTATE 16 IN SOUTHEAST GEORGIA. EXPECT MOST
LOCATIONS...ESPECIALLY INLAND...TO OTHERWISE REMAIN DRY.
TEMPERATURES WILL MODERATE UNDER TRANSITIONING SURFACE FLOW WITHIN
THE ERODING INLAND WEDGE...WITH HIGH TEMPERATURES REACHING THE LOW
TO MID 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A STRONG SHORTWAVE TROUGH WILL SWEEP ACROSS THE NEW ENGLAND AND
MID ATLANTIC STATES ON MONDAY...HELPING TO DRIVE A COLD FRONT
THROUGH THE FORECAST AREA. MEDIUM RANGE MODELS ARE IN DECENT
AGREEMENT THAT THE FRONT WILL BE ASSOCIATED WITH LITTLE SIGNIFICANT
PRECIPITATION...AND WILL THUS CONTINUE TO CAP RAIN CHANCES IN THE
SLIGHT CHANCE RANGE DURING FRONTAL PASSAGE. EXPANSIVE SURFACE HIGH
PRESSURE FOLLOWING IN THE WAKE OF THE COLD FRONT WILL HAVE ORIGINS
FROM THE NORTHERN PLAINS STATES...AND WILL BE ACCOMPANIED BY A
MORE NOTABLE CHANGE IN AIR MASS. AHEAD OF THE FRONT...TEMPERATURES
ON MONDAY WILL ACTUALLY WARM SEVERAL DEGREES WITHIN FRONTAL
COMPRESSION AND DOWNSLOPE FLOW. CONDITIONS WILL THEN QUICKLY
COOL...WITH LOW TEMPERATURES MONDAY NIGHT FALLING INTO THE LOW TO
MID 60S. EXPECT HIGH TEMPERATURES TUESDAY THROUGH MID WEEK TO ONLY
PEAK IN THE LOW 80S. NIGHTTIME LOWS WILL RANGE FROM THE LOW TO
MID 60S. WITH DRY HIGH PRESSURE POSSIBLY LINGERING THROUGH THE
EXTENDED PERIOD...HAVE GENERALLY KEPT RAIN CHANCES IN THE SLIGHT
CHANCE RANGE...HIGHEST ALONG THE COAST AND OFFSHORE.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
BOTH SITES HAVE THE POTENTIAL FOR LATE NIGHT STRATUS AND/OR
FOG...WITH MVFR OR LOWER CONDITIONS TO OCCUR FROM AROUND 09-13Z.
WHILE MOST OF THE REST OF THURSDAY WILL BE VFR...ISOLATED
SHRA/TSRA WILL OCCUR IN THE AFTERNOON AND LATER TAF ISSUANCES MAY
NEED TO ADDRESS THE CONCERN FOR IMPACTS ON BOTH OF EITHER
TERMINAL.
EXTENDED AVIATION OUTLOOK...LOW CLOUDS/FOG WILL BE POSSIBLE WITH
PERIODS OF MVFR OR LOWER CIGS EACH MORNING THROUGH AT LEAST
SATURDAY. OTHERWISE...MAINLY VFR OUTSIDE OF ANY ISOLATED SHOWERS
EACH DAY. IMPROVING CONDITIONS WITH MAINLY VFR SUNDAY AND MONDAY.
&&
.MARINE...
FAIRLY STRAIGHTFORWARD FORECAST THROUGH TONIGHT WITH WIND SPEEDS
MAINLY 10 KT OR LESS TODAY BUT INCREASING A BIT IN ONSHORE FLOW
TONIGHT...NOTHING SUBSTANTIAL. SEAS 2 TO 3 FT IN SWELL WAVE FOR
THE MOST PART. SYNOPTIC PATTERN FAVORS SOME NOCTURNAL CONVECTION
OVER THE WATERS AGAIN TONIGHT.
FRIDAY THROUGH MONDAY...MODERATE NORTHEAST FLOW IS EXPECTED
SATURDAY AND SUNDAY...AS PRESSURE GRADIENT REMAINS TIGHT BETWEEN
INLAND HIGH PRESSURE AND A WAVE OF LOW PRESSURE FARTHER OFFSHORE.
WINDS COULD PEAK AT 15 TO 20 KT WITH SEAS 3 TO 5 FEET
SATURDAY...BEFORE DIMINISHING SUNDAY AND MONDAY AS THE INLAND
WEDGE WEAKENS AHEAD OF AN APPROACHING COLD FRONT.
RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES TODAY. DESPITE ONLY LIGHT ONSHORE WINDS...1-2
FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT AN ENHANCED PERIOD
OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND GEORGIA BEACHES. A
MODERATE RISK OF RIP CURRENTS IS THEREFORE IN PLACE TODAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...
SHORT TERM...WMS
LONG TERM...WMS
AVIATION...
MARINE...WMS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1201 AM MDT THU SEP 18 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 143 PM MDT WED SEP 17 2014
WEAK CONVECTION CURRENTLY DEVELOPING IN EASTERN COLORADO ALONG
PALMER DIVIDE AND WEAK WIND CONVERGENT ZONE WILL MOVE INTO
WESTERN KANSAS THIS AFTERNOON. INITIALLY HIGHER BASED CONVECTION
IN KIT CARSON COUNTY WHERE DEWPOINTS ARE IN THE UPPER 30S SHOULD
EVENTUALLY REACH BETTER MOISTURE AS IT WORKS EAST WHERE DEWPOINTS
ARE IN THE LOW-MID 50S. HRRR RUNS ALL MORNING HAVE CONTINUED TO
INDICATE THE POTENTIAL FOR SCATTERED SHRA/TSRA MAINLY SOUTH OF
I-70 IN KANSAS UNTIL EARLY EVENING. NAM HINTS AT THIS AS WELL.
BOTTOM LINE...HAVE INCLUDED LOW POPS TO ACCOUNT FOR THIS BUT FORCING
APPEARS WEAK AND SOME CINH REMAINS TO BE OVERCOME. OVERALL NOT
EXPECTING A BIG CONVECTIVE EVENT HERE.
WIDESPREAD STRATUS AND LOCALLY DENSE FOG IS LIKELY TO DEVELOP OVER
THE EASTERN HALF OF THE FORECAST AREA AFTER MIDNIGHT. SURFACE
DEWPOINTS WILL HOLD IN THE UPPER 50S AND LOWER 60S WITH CONTINUED
LIGHT SOUTHEAST BOUNDARY LAYER FLOW.
POTENTIAL EXISTS FOR OVERNIGHT CONVECTION...MAINLY AFTER MIDNIGHT...
EAST OF A TRENTON NEBRASKA TO HOXIE KANSAS LINE. GFS/NAM GUIDANCE
BOTH GIVE SUPPORT TO A SSE-NNW ORIENTED BAND OF SHOWERS AND
THUNDERSTORMS...ALTHOUGH TIMING AND PLACEMENT DIFFERS SOMEWHAT
BETWEEN MODELS. 500-1000 J/KG OF ELEVATED CAPE IS PRESENT TO
SUPPORT CONVECTION IF INHIBITION IS OVERCOME.
TEMPERATURES SHOULD CHANGE LITTLE NEXT COUPLE DAYS AS UPPER RIDGE
OVER THE ROCKIES SHIFTS EAST TO THE CENTRAL HIGH PLAINS. HIGHS
THURSDAY WILL AGAIN BE ABOVE NORMAL AROUND 90F GIVEN FORECAST 850
MB TEMPS 26-30C.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED SEP 17 2014
THURSDAY NIGHT-SATURDAY...FOCUS FOR THIS PORTION OF THE FORECAST IS
THE TRACK OF WHATS NOW WEAKENING TROPICAL STORM ODILE.
DEEP MOISTURE (WITH PRECIPITABLE WATER VALUES AROUND 1.5 INCHES)
ASSOCIATED WITH THE REMNANTS OF THIS SYSTEM ARE FORECAST TO REACH
AREAS SOUTH OF INTERSTATE 70 LATE FRIDAY AFTERNOON...SLIDING SLOWLY
EAST FRIDAY NIGHT AND OUT OF THE AREA EARLY SATURDAY MORNING. THE
GFS IS SLIGHTLY FURTHER SOUTH WITH THE PLUME OF MOISTURE COMPARED TO
THE 12Z NAM/00Z ECMWF...SO NO SLAM DUNK ON PRECIPITATION AMOUNTS
WITH THIS SYSTEM NOR HOW HIGH TO GO WITH POPS. IT APPEARS THAT
EITHER WAY...AS MENTIONED ABOVE...HIGHEST POPS WILL BE ALONG OR
SOUTH OF THE INTERSTATE. SOME LOCALLY HEAVY RAINFALL IS POSSIBLE IF
THE FURTHER NORTH NAM/ECMWF VERIFY.
SOUTH TO SOUTHWEST WINDS FRIDAY MID MORNING THROUGH AFTERNOON
GUSTING IN THE 25-35 MPH RANGE.
FOR SATURDAY AFTERNOON SOME MOISTURE MOVES IN FROM THE NORTHWEST
ASSOCIATED WITH AN UPPER TROUGH PASSAGE. CANT RULE OUT A FEW SHOWERS
AND MAYBE A THUNDERSTORM WITH IT WITH SLIGHT CHANCE POPS AT BEST.
SATURDAY NIGHT...DRY WITH MAYBE SOME HIGH CLOUDS MOVING IN FROM THE
WEST/SOUTHWEST.
LOWS THURSDAY NIGHT MID 50S TO MID 60S WITH SIMILAR...MAYBE A TAD
COOLER READINGS FRIDAY NIGHT.
HIGHS FRIDAY IN THE 80S WITH UPPER 70S TO LOW 80S SATURDAY.
SUNDAY-SUNDAY NIGHT...DRY WEATHER EXPECTED. MID AND HIGH CLOUDS
INCREASE FROM THE SOUTHWEST...ESPECIALLY LATE IN THE AFTERNOON
THROUGH THE NIGHT...AHEAD OF AN UPPER LEVEL LOW PRESSURE AREA MOVING
NORTHEAST TOWARD THE SLC AREA. HIGHS IN THE MID TO UPPER 70S WITH
LOWS IN THE LOW TO MID 50S. WILL BE INTRODUCING SOME SLIGHT CHANCE
TO LOW CHANCE POPS FOR SHOWERS/ISOLATED THUNDERSTORMS FOR THE
WESTERN 1/2 OF THE AREA. HIGH TEMPERATURES MID 70S TO AROUND 80 WITH
LOWS IN THE LOW TO MID 50S.
MONDAY-MONDAY NIGHT...SCATTERED TO BROKEN CLOUDINESS CONTINUES AS
THE UPPER LOW AND ASSOCIATED TROUGH LIFTS NORTHEAST TOWARD EASTERN
WYOMING. WILL NEED TO MAINTAIN SOME LOW CHANCES FOR
SHOWERS/THUNDERSTORMS. HIGHS IN THE LOW TO MID 70S WITH LOWS IN THE
LOW TO MID 50S.
TUESDAY-WEDNESDAY...UPPER LOW AND ASSOCIATED TROUGH FORECAST TO MOVE
EAST/SOUTHEAST TOWARD NORTHEAST NEBRASKA BY THE END OF THE PERIOD.
CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY SLOWLY DECREASING IN
COVERAGE FROM WEST TO EAST WEDNESDAY AS MOISTURE DECREASES FROM WEST
TO EAST WITH PASSAGE OF UPPER TROUGH. HIGHS TUESDAY IN THE LOW 70S
WITH LOW TO MID 70S WEDNESDAY. LOWS TUESDAY NIGHT IN THE LOW TO MID
50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1147 PM MDT WED SEP 17 2014
VFR TO LIFR CONDITIONS FORECAST FOR THE 6Z TAFS. SOUNDINGS FOR
KMCK SHOW A SATURATED LAYER 1.5K FT DEEP. ABOVE THAT LAYER THE
ENVIRONMENT DRIES OUT...WITH BREEZY SOUTHEAST WINDS AT THE TOP OF
THE SATURATED LAYER POSSIBLY MIXING THE DRIER AIR INTO THE
SATURATED LAYER. SEEMS THIS SETUP USUALLY FAVORS STRATUS MORE
THAN FOG...SO WILL KEEP VIS IN THE MVFR CATEGORY. STRATUS SHOULD
CLEAR BY EARLY AFTERNOON FOR KMCK.
FOR KGLD MVFR VIS SEEMS APPROPRIATE GIVEN COLBY IS ALREADY DOWN TO
4 MILES. THERE COULD BE SOME DENSER FOG JUST NORTH OF THE SITE.
HOWEVER WITH MOS NOT FAVORING MORE THAN MVFR RESTRICTIONS AND
SINCE SOUNDINGS FOR KGLD ALSO SHOW BREEZY WINDS AT THE TOP OF THE
SATURATED LAYER...DO NOT BELIEVE THE VIS. SHOULD DROP BELOW 3SM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...99
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
337 PM CDT THU SEP 18 2014
.SHORT TERM...
UPPER TROUGH LOCATED OVER THE NORTHEAST UNITED STATES IS IN THE
PROCESS OF LIFTING OUT INTO THE ATLANTIC OCEAN. THIS HAS ALLOWED FOR
MOISTURE THAT GOT PUSHED INTO THE GULF YSTRY...BACK INTO THE AREA.
ALTHOUGH MOST ONGOING SHOWERS IN THE CWA ARE SOUTH OF THE LA
COAST...A FEW HAVE BEGUN TO DEVELOP OVER INLAND AREAS. MCV CURRENTLY
LOCATED ALONG THE SOUTHERN LA/TX BORDER APPEARS TO BE GRADUALLY
SHIFTING SOUTHEAST...MORESO ON THE COASTAL INTERFACE BETWEEN
VERMILLION BAY AND THE TX BORDER. HRRR DOES SHOW SOME BLOWOVER FROM
THAT FEATURE TO MOVE INTO THE CWA ALONG AND SOUTH OF INTERSTATE 10
DURING THE EVENING HOURS. THE INTENSITY WILL LIKELY BE IN A A
DECAYING PHASE. SO ALTHOUGH POPS ARE HIGHER IN THE FORECAST FOR THIS
EVENING...MOST ACTIVITY SHOULD BE QUITE LIGHT WITH NOT TOO HIGH OF
QPF OUTSIDE OF ISOLATED TO SCATTERED THUNDERSTORMS THAT DEVELOP
BEFOREHAND.
.LONG TERM...
FRIDAY THROUGH THE WEEKEND WILL BE A TRANSITION PERIOD AS SLIGHT
UPPER RIDGING TRANSLATES ACROSS THE SOUTHERN CONUS BEFORE THE NEXT
TROUGH MOVES ACROSS THE GREAT LAKES. THIS WILL SUPPRESS MOST
CONVECTION AND HAVE LIMITED CONVECTION FRIDAY THROUGH SUNDAY WITH
ONLY COASTAL AREAS SEEING ANY STORMS. GFS AND ECMWF STILL SHOWING
THE NEXT SOMEWHAT DECENT COLD FRONT MOVING INTO THE AREA EARLY NEXT
WEEK AS THE AFOREMENTIONED TROUGH DIGS INTO THE SOUTHEAST.
TEMPS MAY COOL OFF A FEW DEGREES WITH THE POSSIBILITY IF LOWER 60S
FOR MORNING LOWS IN THE SOUTHWEST MS ZONES. RAIN CHANCES WILL BE LOW
DURING THAT PERIOD AS WELL.
MEFFER
&&
.MARINE...
LIGHT EASTERLY FLOW OF 5 TO 10 KNOTS AND SEAS OF 1 TO 2 FEET WILL BE
FOUND OVER THE WATERS TODAY AND TONIGHT. GRADIENT FLOW WILL INCREASE
BEGINNING TOMORROW WITH A PERIOD OF EXERCISE CAUTION CONDITIONS
EXPECTED OVER THE GULF COASTAL WATERS BY LATE TOMORROW AFTERNOON AND
PERSISTING INTO SATURDAY EVENING. THIS INCREASED EASTERLY FLOW WILL
BE IN RESPONSE TO A WEAK LOW PRESSURE SYSTEM MOVING OFF THE TEXAS
COAST AND THEN PUSHING EASTWARD ACROSS THE CENTRAL GULF TOWARD
FLORIDA COMBINED WITH HIGH PRESSURE BUILDING SOUTHWESTWARD ALONG THE
APPALACHIANS. WITH STRONGER WINDS IN PLACE...SEAS WILL
CORRESPONDINGLY RISE TO AROUND 3 TO 5 FEET FRIDAY NIGHT.
SOME HIGHER THAN NORMAL TIDES WILL ALSO BE POSSIBLE BY SATURDAY
GIVEN THE PERSISTENT STRONG ONSHORE FLOW. TIDES WILL BE MOST
ELEVATED ALONG EAST FACING SHORES. AS THE LOW PULLS EAST OF THE
AREA...THE GRADIENT WILL RELAX THROUGH THE DAY ON SUNDAY...WITH A
RETURN TO LIGHTER EASTERLY FLOW OF 5 TO 10 KNOTS FOR MONDAY. SEAS
WILL ALSO FALL BACK TO 2 TO 3 FEET BY MONDAY. THESE CONDITIONS WILL
PERSIST THROUGH TUESDAY. 35
&&
.AVIATION...
EXTENSIVE CIRRUS SHIELD THIS AFTERNOON ACROSS THE AREA. THERE IS
STILL ENOUGH HEATING GOING ON TO TRIGGER SOME ISOLATED WEAK
CONVECTION ACROSS THE AREA...ALTHOUGH NO LIGHTNING REPORTED YET.
MAIN CONVECTION IS OVER SOUTHEAST TEXAS AND THE GULF OF MEXICO...AS
WELL AS SOUTHERN ARKANSAS AND NORTH CENTRAL MISSISSIPPI. MESOSCALE
MODELING TENDS TO PICK UP ONE OF THESE AREAS...BUT NOT BOTH. IN
EITHER CASE...ANY SIGNIFICANT AREAL COVERAGE IS LIKELY TO HOLD OFF
UNTIL AFTER SUNSET...AND WILL CARRY VCTS IN MOST TERMINALS
OVERNIGHT...WITH THE EXCEPTION OF KGPT AND KASD. HIGH AND MID CLOUDS
SHOULD HANG IN OVERNIGHT WHICH MAY PRECLUDE A REPEAT OF FOG/LOW
CLOUD DEVELOPMENT EARLY FRIDAY MORNING. 35
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT AND SUPPORTING USCG SSW OF PASCAGOULA.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 66 87 67 88 / 30 0 10 10
BTR 68 86 70 87 / 50 10 10 10
ASD 74 84 76 87 / 30 20 10 10
MSY 73 84 76 89 / 50 20 10 10
GPT 75 87 76 86 / 30 20 10 10
PQL 74 87 75 87 / 20 20 10 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1040 AM CDT THU SEP 18 2014
.UPDATE...
WV/IR SATELLITE SHOW INCREASED STRATOCU PUSHING INTO THE AREA. THE
LATEST SHORT TERM GUIDANCE APPEARS TO HAVE A GOOD GRASP OF THE
CURRENT CONDITIONS WITH THE STATIONARY FRONT LOCATED FROM CENTRAL
TEXAS THROUGH NORTHERN LOUISIANA AND A FAIRLY STRONG UPPER LEVEL
DISTURBANCE JUST OFFSHORE. THIS IS FORCING A BROAD AREA OF MOSTLY
STRATOFORM SHOWERS OVER PARTS OF SETX NEAR THE HOUSTON AREA RIGHT
NOW. UPPER LEVEL WINDS ARE RELATIVELY WEAK AND THUS THE STORM
MOTION OF THAT SYSTEM IS EXPECTED TO BE SLOW. LATEST HRRR GUIDANCE
SUGGESTS THAT THE TIMING OF THE ONSET OF THE HEAVIEST SHOWERS
SHOULD BE AROUND 17Z AND NOT PROJECTED TO MOVE VERY QUICKLY ACROSS
SETX. TIMING OF THE SHOWERS MOVING OUT OF THE AREA IS SOMEWHERE
BETWEEN 22Z TO 01Z THIS EVENING. STORM TOTAL QPF OVER SETX IS
STILL IN THE BALL PARK OF 1 TO 2 INCHES SO I CHOOSE TO NOT INCLUDE
A FLASH FLOOD WATCH ALTHOUGH SOME URBAN FLOODING COULD BE
POSSIBLE.
DEAL
&&
.PREV DISCUSSION... /ISSUED 631 AM CDT THU SEP 18 2014/
AVIATION...
A STATIONARY FRONT DRAPES THROUGH DALLAS THROUGH LAFAYETTE THIS
MORNING...SLOPING TOWARD THE GULF AIR WITH HEIGHT. THE FRONTAL
SURFACE SEPARATES MOIST UNSTABLE AIR SOUTH AND WEST...FROM DRIER
STABLE AIR NORTH AND EAST.
NORTHWESTERLY SHORTWAVES ALOFT WILL TRAVEL OVER THE FRONTAL ZONE
..SETTING OFF SCATTERED SHOWERS AND THUNDERSTORMS. THE HEAVIEST
ACTIVITY WILL BE ALONG THE BEAUMONT TO LAKE CHARLES AIR CORRIDOR.
JT
PREV DISCUSSION... /ISSUED 349 AM CDT THU SEP 18 2014/
DISCUSSION...LOCAL RADAR DEPICTING JUST A BIT OF LIGHT RAIN OR
DRIZZLE OVER EAST TEXAS JUST CLIPPING OUR WESTERN MOST COUNTIES.
STRATOFORM PRECIP EXTENTS EAST FROM MORE ROBUST CONVECTION OVER
SOUTH CENTRAL TEXAS WHICH IS ADVANCING SOUTHEAST. SURFACE OBS OVER
THE FORECAST AREA SHOWING LITTLE IN THE WAY OF FOG...AND WITH
EXTENSIVE CLOUDINESS INCOMING EXPECT THAT TO REMAIN THE CASE.
TODAY...NORTHWEST TO SOUTHEAST MOISTURE AXIS SET UP OVER THE
SOUTHERN PORTION OF THE FORECAST AREA WILL CONTINUE TO BE THE
FOCUS FOR SHOWERS AND THUNDERSTORMS. PRECIPITABLE WATER PROGGED
AS HIGH AS 2.5 INCHES AT BPT AT 18Z...BUT TRENDING TOWARD THE NORM
AT AEX COMING IN AT 1.8 INCHES. WITH THAT SAID...POPS WILL
CONTINUE TO BE ALIGNED ACCORDINGLY FROM CATEGORICAL FOR THE
SOUTHWEST PORTION OF THE FORECAST AREA...TO JUST A CHANCE ADVANCING
INTO CENTRAL LOUISIANA. INCREASED ACTIVITY EXPECTED TODAY WITH THE
APPROACH AND PASSAGE OF A VIGOROUS SHORTWAVE TROF. GUIDANCE
SUGGESTING HEAVIEST RAINS OVER LOWER SOUTHEAST TEXAS INCLUDING THE
BEAUMONT AREA. QPF SHOWING 1 TO 2 INCHES.
WITH EASTWARD ADVANCEMENT OF SHORTWAVE AND AMPLIFICATION OF MID-CONUS
TROF...THE AREA WILL COME UNDER A DEEP NORTHERLY FLOW. THIS WILL
SHUNT THE DEEP MOISTURE INTO THE GULF WATERS RESULTING IN DECREASING
RAIN CHANCES OVER THE AREA MOVING THROUGH FRIDAY. WITH EXTENT OF
DRIER AIR INCOMING...HAVE OPTED TO REMOVE ANY RAIN CHANCE FOR SATURDAY.
THE NEW WEEK...COLD FRONT EXPECTED TO MOVE ACROSS THROUGH MONDAY.
MOISTURE WILL BE SOMEWHAT LIMITED AND SIMPLY CARRYING LOW END POPS
AT THIS TIME. SUFFICIENT MOISTURE REMAINS IN PLACE AFTER FROPA TO
MAINTAIN A CONTINUED CHANCE FOR A FEW SHOWERS. OTHERWISE LOOKING
FOR SLIGHTLY COOLER TEMPS AND LOWER HUMIDITY FOR THE WEEK.
MARINE...WIDESPREAD SHOWERS AND THUNDERSTORMS CAN BE EXPECTED
OVER THE NORTHWEST GULF TODAY. THIS AS DEEP TROPICAL MOISTURE
REMAINS IN PLACE...IN CONCERT WITH A VIGOROUS UPPER LEVEL
DISTURBANCE ADVANCING THROUGH. RAIN CHANCES WILL DIMINISH FOR
FRIDAY AND THE WEEKEND AS THE DEEP MOISTURE IS DISPLACE SOUTHWARD
WITH PASSAGE OF THE DISTURBANCE AND AMPLIFICATION OF A MID-CONUS
RIDGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 83 72 86 71 89 / 80 60 30 10 10
KBPT 82 72 85 73 88 / 80 60 50 10 10
KAEX 85 69 87 69 91 / 50 30 20 10 10
KLFT 85 72 86 71 89 / 60 40 20 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSLAKECHARLES
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1217 AM CDT THU SEP 18 2014
.AVIATION...
FOR THE 18/06Z TAFS...TWO AREAS OF CONVECTION WILL AFFECT THE AREA
EARLY IN THE TAF PERIOD. A BROKEN LINE OF CONVECTION IS MOVING SWD
INTO SE OK/EXTREME SW AR. THIS LINE HAS SHOWN A TENDENCY TO
BACK-BUILD TOWARDS THE WEST SO BELIEVE THESE STORMS WILL REMAIN W
OF KTXK. THESE STORMS HAVE BEEN CYCLING BUT HAVE SHOWN SOME SIGNS
OF DIMINISHING SO CURRENT THINKING IS THEY WILL NOT PERSIST S OF
I-30 BUT CANNOT RULE OF CONVECTION AFFECTING KTYR/KGG LATER THIS
MORNING. FARTHER S...THE ERN EDGE OF A LARGE AREA OF RAIN MAY
AFFECT KLFK FOR A COUPLE OF HRS.
OTHERWISE...LOW CLOUDS AND FOG ARE LIKELY ACROSS MUCH OF THE AREA
ONCE AGAIN THIS MORNING LEADING TO MVFR/IFR FLIGHT CONDITIONS.
IMPROVEMENT BACK INTO THE VFR RANGE IS EXPECTED BY MID TO LATE
MORNING. MORE CONVECTION IS EXPECTED TO DEVELOP AND AFFECT MUCH OF
THE AREA DURING THE DAY THURSDAY. LINGERING FRONTAL BOUNDARY AND
INCREASING MOISTURE/ASCENT FROM THE REMNANTS OF HURRICANE ODILE
MAY ALLOW CONVECTION TO PERSIST LATE INTO THE TAF PERIOD. /09/
&&
.PREV DISCUSSION... /ISSUED 900 PM CDT WED SEP 17 2014/
DISCUSSION...
LOCAL AND REGIONAL RADARS CONTINUE TO SHOW A WELL DEFINED
DISTURBANCE ACROSS EAST CENTRAL OKLAHOMA INTO WEST CENTRAL
ARKANSAS MOVING SOUTH SOUTHWEST IN WEAK NW FLOW ALOFT. THIS
CLUSTER OF STRONG/SEVERE THUNDERSTORMS HAS DEVELOPED A COLD POOL
WHICH IS HELPING TO INITIATE AND SUSTAIN THE CONVECTION EVEN AFTER
SUNSET. LATEST MESOANALYSIS SHOWS CAPE NEAR 2000 J/KG IN OUR
VICINITY OF SE OK INTO SW AR WHICH SUGGESTS THAT THE CONVECTION
SHOULD CONTINUE TO COME SOUTH AT LEAST INTO OUR FAR NW ZONES LATER
THIS EVENING. LATEST HRRR SUPPORTS THIS SCENARIO WITH THE
CONVECTION WEAKENING QUICKLY JUST BEFORE IT MAKE IT TO TXK. FOR
THIS REASON...HAVE RAISED POPS TO CHANCE CATEGORY ACROSS OUR NW
ZONES THIS EVENING.
ELSEWHERE...CONVECTION IS MORE ISOLATED IN NATURE ACROSS NE TX
DESPITE INCREASING MOISTURE ACROSS OUR SW ZONES. PWATS NEAR 2
INCHES EXIST MAINLY TO THE WEST OF A LINE FROM TYR TO THE LOWER
TOLEDO BEND RESERVOIR AND THIS IS WHERE WE WILL CONTINUE TO
ADVERTISE LOW END CHANCE POPS OVERNIGHT. CONVECTION ACROSS CENTRAL
TEXAS ATTM SHOWING NO TENDENCY TO WANT TO MOVE TOWARDS OUR REGION
FROM THE WEST SO LOW END CHANCE POPS ACROSS THIS REGION SHOULD
SUFFICE.
DEWPOINT TEMPERATURES ARE QUITE A FEW DEGREES HIGHER TONIGHT
COMPARED TO 24 HOURS AGO GIVEN AND GIVEN THE INCREASING MOISTURE
FROM THE SOUTHWEST...THIS WILL LIKELY HAVE AN EFFECT ON OUR
TEMPERATURES ACROSS A FEW LOCATIONS. BUMPED OVERNIGHT LOWS UP
ACROSS OUR EASTERN MOST ZONES MAINLY. ELSEWHERE...LOWER 70S SHOULD
SUFFICE EXCEPT FOR UPPER 60S ACROSS OUR EXTREME NW ZONES WHERE
CONVECTION COULD ALLOW TEMPERATURES TO FALL BELOW 70 DEGREES.
OTHERWISE...ALL OTHER FORECAST PARAMETERS ARE IN PRETTY GOOD SHAPE
WITH NO OTHER CHANGES NECESSARY ATTM.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 68 92 70 91 72 / 10 10 10 10 10
MLU 67 92 68 92 69 / 10 10 10 10 10
DEQ 66 88 67 89 68 / 10 10 10 10 30
TXK 67 89 69 90 70 / 10 10 10 10 20
ELD 67 89 67 90 69 / 10 10 10 10 10
TYR 68 89 70 90 72 / 20 10 10 20 20
GGG 67 90 69 91 71 / 20 10 10 10 10
LFK 69 91 70 91 71 / 20 20 10 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
330 PM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM EDT THU SEP 18 2014
UPPER LEVEL PATTERN TRANSITIONS FROM NORTHWEST FLOW ON BACK SIDE OF
TROUGHING OVER EASTERN CANADA TO MORE ZONAL FLOW BY THIS WEEKEND.
MAIN REASON THIS OCCURS IS 125+ KT H25 JET STREAK PLOWING ACROSS
PACIFIC TOWARD BRITISH COLUMBIA AND PACIFIC NORTHWEST. AS THIS JET
ENERGY REACHES NORTHERN PLAINS ON FRIDAY IT WILL HELP DEVELOP TROUGH
ALOFT OVER NORTHERN ONTARIO AND THE LK SUPERIOR REGION. INITIAL WAVE
ON LEADING EDGE OF THIS TROUGH WORKS THROUGH FRIDAY NIGHT INTO
SATURDAY MORNING AND THIS SHOULD BE WHEN MAJORITY OF RAIN OCCURS.
AT THE SFC...A TROUGH WITH A WIND SHIFT AND LOW-LEVEL DRYING WILL
MOVE THROUGH. ANOTHER SHORTWAVE IS FORECAST TO SWING THROUGH
SATURDAY NIGHT INTO SUNDAY MORNING. A STRONGER SFC COLD FRONT
WILL ACCOMPANY THAT SHORTWAVE. WARMER THAN NORMAL TEMPS FRIDAY NIGHT
INTO SATURDAY...BEFORE TEMPERATURES FALL BACK BELOW NORMAL ON SUNDAY.
LOW TEMPS ON FRIDAY NIGHT MAY NOT FALL BLO 60 DEGREES IN SOME AREAS
AS THE WARM SOUTH/SOUTHWEST WINDS PERSIST. THOUGH THERE COULD BE LOW
CLOUDS AROUND TO START THE DAY ON SATURDAY...APPEARS THERE WILL BE
ENOUGH MIXING BY LATE MORNING/EARLY AFTN TO RESULT IN MIXING HEIGHTS
BUILDING TO AT LEAST TO H9/H875 WITH HIGHS POTENTIALLY WELL INTO THE
70S IF THERE IS AT LEAST PARTIAL SUNSHINE. MUCH DIFFERENT STORY ON
SUNDAY WITH HIGHS NEAR LK SUPERIOR BARELY REACHING ABOVE 50 DEGREES
AND ONLY INTO THE 50S FARTHER INLAND AND OVER SOUTHERN CWA AND NEAR
LK MICHIGAN. NOTHING TOO HIGH IMPACT IN TERMS OF NORTH TO NORTHWEST
WINDS IN WAKE OF THE COLD FRONT ON SUNDAY...WITH 20-30 MPH ON LK
SUPERIOR AND NEAR THE SHORE...NOTHING TOO ATYPICAL FOR SEPTEMBER.
BACK TO THE IMPACTS TIED TO SYSTEM MOVING THROUGH FRIDAY NIGHT
THROUGH SATURDAY. DOES NOT APPEAR THAT HEAVY RAIN WILL BE A LARGE
THREAT WITH THIS SYSTEM...MAINLY BECAUSE THE GREATEST SURGE OF H85
THETA-E ADVECTION AND PWATS NEAR 200 PCT OF NORMAL ONLY OCCURS FOR
BRIEF PERIOD ON FRIDAY NIGHT BEFORE THE H85 JET VEERS MORE WEST BY
12Z SATURDAY. SOUTH WINDS AHEAD THE INITIAL LOW PRESSURE SYSTEM AND
SFC TROUGH WILL BE STRONG AND GUSTY FRIDAY EVENING. SOUNDINGS SHOW
STABLE PROFILE BLO AN INVERSION AT H9-H85...BUT BLYR WINDS ARE STILL
IN THE 40-50 MPH RANGE. PRESSURE FALLS OVER EASTERN LK SUPERIOR TO
JAMES BAY WILL ENHANCE THE SOUTH WINDS. OVERALL...COULD SEE SOUTH
WINDS GUSTING OVER 35 MPH VCNTY OF EASTERN LK SUPERIOR AND NORTHERN
LK MICHIGAN WITH SOME GUSTS 30-35 MPH ON THE LAND AREAS OF THE
EASTERN CWA. ATTM THINK THE WIND GUSTS SHOULD STAY BELOW ADVY
CRITERIA OF 45 MPH.
ADDITIONAL IMPACT COULD BE STRONG OR POSSIBLE SEVERE STORMS ON
SATURDAY AFTN AS SFC TROUGH CROSSES THE AREA ALONG WITH SHORTWAVE
AND PUSH OF MID-LEVEL MOISTURE. MLCAPES UP OVER 1500J/KG AND WITH
THE UPPER TROUGH IN THE VCNTY...0-6KM SHEAR IS OVER 40 KTS. NAM
QUITE AGGRESSIVE DEPICTING BUILD UP OF INSTABILITY...WHILE THE GFS
AND ECMWF ARE NOT AS MUCH. SREF PROBABILITIES OF MUCAPE OVER
1000J/KG ALONG WITH SHEAR OVER 30 KTS SHOW SOME INCREASE 15-21Z
SATURDAY OVER MAINLY THE SCNTRL CWA...BUT STILL REMAIN MAINLY BLO 10
PCT. FREEZING LEVEL IS 9-11KFT AND HEIGHT THAT CORES ALOFT WOULD
HAVE TO REACH TO POSSIBLY PRODUCE SEVERE 1 INCH HAIL IS 27-30KFT...
SO LARGE HAIL IS A POSSIBILITY. LOW-LEVEL LAPSE RATES NOT THAT
STEEP...BUT WITH THE DRY AIR H9-H7 AND STRONG WINDS H7-H5...SUPPOSE
STRONG WIND GUSTS COULD MAKE IT TOO SFC. PRIMARY AREA HIGHLIGHTED IN
SPC DAY3 OUTLOOK IS FARTHER EAST AND SOUTH AHEAD OF COLD FRONT
WITHIN SW H85 JET AND WHERE THE SFC DWPNTS ARE WELL INTO THE 60S.
DOES SEEM IF TIMING WORKS OUT WHERE SOME INSTABILITY CAN BUILD OVER
CNTRL UPR MICHIGAN AHEAD OF THE SHORTWAVE...THERE IS ENOUGH OF A
RISK FOR SEVERE...SO WILL CONTINUE TO MENTION IN THE HWO.
INTO SATURDAY NIGHT...COULD STILL SEE SOME TSRA WITH COMBINATION OF
SHORTWAVE AND STEEP H7-H4 LAPSE RATES/COLD POCKET AT H5/. NO STRONG
STORMS EXPECTED THROUGH AS EFFECTIVE SHEAR DIMINISHES TO LESS THAN
20 KTS BY THIS TIME. BESIDES THE CHILL THAT WILL BE IN THE AIR ON
SUNDAY...ANOTHER SHORTWAVE DROPPING THROUGH IN NW FLOW ALOFT AND THE
H85-H5 THERMAL TROUGHING/EXTENSIVE MOISTURE WILL LIKELY BE ENOUGH TO
KICK OFF SOME SHOWERS OVER MAINLY INLAND AREAS. WATER TEMPS OVER
MUCH OF LK SUPERIOR ARE IN THE 6-8C RANGE BASED ON BUOYS AND SHIP
REPORTS. IMMEDIATE NSH AREAS OF SCNTRL LK SUPERIOR MAY BE OVER 10C
IN SOME SPOTS BUT THAT IS LOCALIZED. THEREFORE WITH H85 TEMPS STAYING
ABOVE 0C WILL NOT BE LOOKING AT MUCH LAKE ENHANCEMENT ESPECIALLY AS
LOW-LEVEL FLOW WILL BE TRENDING MORE ANTICYCLONIC THROUGH THE DAY
WITH SFC RIDGE EXPANDING EAST FM THE NORTHERN PLAINS.
EXTENDED...TROUGHING ALOFT DOMINATES EARLY NEXT WEEK. HINT OF
STRONGER SHORTWAVE AND RE-INFORCING SFC TROUGH DROPPING ACROSS
THE UPPER GREAT LAKES ON MONDAY. GFS FARTHER WEST WITH THE WAVE AND
WOULD INDICATE AT LEAST ISOLD SHRA ON MONDAY. ECMWF AND GEM-NH AND
PREVIOUS FORECASTS...KEEP BULK OF WAVE AND MOISTURE TOO FAR EAST TO
RESULT IN MUCH SHRA. SINCE GFS IS ALSO TRENDING THIS WAY WITH 12Z
RUN...WILL KEEP IT DRY ATTM. HIGH PRESSURE INITIALLY AT THE SFC THEN
ALOFT AS WELL BUILDS ACROSS REGION TUESDAY THROUGH THURSDAY. PWATS
LESS THAN 50 PCT OF NORMAL AND AFTN SFC DWPNTS IN THE 30S INDICATE
THERE COULD BE FROST TUESDAY NIGHT/WEDNESDAY NIGHT FOR ALL INLAND
AREAS AND MAYBE EVEN THURSDAY NIGHT FOR INLAND AREAS OF EASTERN CWA.
DAYTIME TEMPS WILL LIKELY BE AT OR ABOVE NORMAL...ESPECIALLY
WEDNESDAY INTO THURSDAY AS WARMER AIR WORKS IN ALOFT /H85 TEMPS OVER
10C/ WITH THE BUILDING UPPER RIDGE. SINCE IT LOOKS LIKE THERE WILL
BE LITTLE IN WAY OF CLOUD COVER EITHER DAY...TEMPS COULD EVEN REACH
THE 70S. NORMAL HIGHS FOR MID-LATE SEPTEMBER ARE IN THE MID TO UPPER
60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 146 PM EDT THU SEP 18 2014
LOW-LEVEL MOISTURE WRAPPING AROUND THE BACKSIDE OF HIGH PRESSURE
OVER THE REGION WILL CONTINUE WITH MVFR CIGS AT IWD...AND BRING MVFR
CIGS TO CMX AND SAW OVERNIGHT THROUGH MUCH OF FRIDAY. AN INCREASING
PRESSURE GRADIENT ACROSS THE REGION WILL ALLOW FOR GUSTY S TO SSW
WINDS AT ALL SITES BEGINNING FRIDAY MORNING...ESPECIALLY AT SAW.
EXPECT GUSTS AS HIGH AS 30KTS DURING THE AFTERNOON HOURS. AN
APPROACHING LOW-LEVEL TROUGH IS EXPECTED TO BRING -SHRA TO WESTERN
UPPER MI DURING THE AFTERNOON...BUT ANY PRECIP SHOULD HOLD OFF AT
IWD OR CMX UNTIL AFTER 18Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KLUBER
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
147 PM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 459 AM EDT THU SEP 18 2014
MAIN FCST CONCERN FOCUSES ON CHCS FOR SHRA FRI THRU SUN AS A SERIES
OF SHRTWVS IN A W-NW FLOW MOVE ACROSS THE UPPER GREAT LAKES REGION.
MODELS COMING INTO BETTER AGREEMENT SHOWING THE FIRST IN A SERIES OF
SHORTWAVES MOVING INTO THE NRN PLAINS ON FRI. STRENGTHENING WAA AND
INCREASINGLY MOIST SW FLOW AHEAD OF THIS SHORTWAVE AND ITS ASSOC
TROUGH/FRONTAL BOUNDARY OVER THE NRN PLAINS WILL INCREASE PWAT
VALUES TO 1.5 INCHES OR HIGHER (MORE THAN 180 PCT OF NORMAL) OVER
THE FCST AREA BY FRI AFTERNOON. MODEL SNDGS INDICATE 500-1000 J/KG
OF MUCAPE AND SHOWALTER INDICES DROPPING AS LOW AS -2 TO -4C BY FRI
AFTERNOON/FRI NIGHT SO WOULD EXPECT AN INCREASING POTENTIAL FOR
ELEVATED TSRA AS THE WARM FRONT APPROACHES LATE IN THE DAY. MODEL
CONSENSUS SUGGESTS THE BEST CHC FOR SHOWERS WL BE OVER THE W HALF
OF THE CWA FRI AFTERNOON AND OVER THE E HALF FRI EVNG...WHEN
ISENTROPIC ASCENT/H925-7 MSTR TRANSPORT AND DEEP LAYER Q-VECT CONV
WL BE MAXIMIZED OVER THOSE AREAS. AS FOR TEMPS...INCREASING CLD COVER
WL HOLD DOWN SFC HI TEMPS INTO THE 60S ON FRI DESPITE INFLUX OF MUCH
WARMER AIR. EXPECT RELATIVELY SMALL TEMP FALL ON FRI NGT WITH STRONG
SW FLOW AND INFLUX OF HIGHER PWAT.
SAT...ANOTHER STRONGER SHRTWV APPROACHING FROM SCNTRL CANADA AND THE
NRN PLAINS WILL PROPEL THE SFC LOW PRES TROUGH AND ASSOC COLD FNT
THRU THE UPR LAKES. THERE MAY BE A BETTER CHANCE OF SHOWERS/TS
AGAIN SAT AFTERNOON MAINLY OVER CENTRAL AND ERN COUNTIES AS DYNAMICS
WITH SHORTWAVE LOOK TO BE IN SYNC WITH DAYTIME HEATING AND TIMING OF
COLD FRONTAL PASSAGE. MLCAPES FCST IN EXCESS OF 1000 J/KG WOULD
SUPPORT THUNDER AND WITH DEEP LAYER SHEAR VALUES OF 45-50 KTS A FEW
STRONG TO POSSIBLY SVR STORMS WOULD NOT BE OUT OF THE QUESTION IF
INSTABILITY IS REALIZED. WILL MENTION THIS POTENTIAL IN HWO.
DEPENDING ON HOW QUICKLY THE SFC COLD FNT PASSES ON SAT AND
POTENTIAL BREAKS IN CLOUD COVER...SOME PLACES MAINLY OVER THE CNTRL
CWA COULD SEE TEMPS RISE WELL INTO THE 70S AS H85 TEMPS ARE FCST TO
PEAK AS HI AS 16-17C.
SAT NGT INTO SUN...ALTHOUGH MODELS SHOW TIMING DIFFERENCES...THEY
SEEM TO BE IN AGREEMENT THAT ADDITIONAL SHRTWVS WILL BE DROPPING
INTO THE GREAT LKS THAT ARE FCST TO DEEPEN AN UPR TROF OVER THE
REGION. THE RESULTING NW CYCLONIC FLOW OVER THE AREA ALONG WITH THE
PASSAGE OF A SECONDARY COLD FRONT SHOULD YIELD A GOOD DEAL OF CLD
COVER...PERIODS OF SHOWERS AND COOLER WX AS H85 TEMPS DROP FM AS HI
AS 15C ON SAT AFTN TO AS LO AS 2-4C BY LATE SUN. IT APPEARS
UNLIKELY THAT H85 TEMPS WL FALL ENOUGH TO REALIZE MUCH OF A LK
ENHANCED COMPONENT TO THE CLDS/SHOWERS SUN AND SUN NGT WITH WSHFT TO
THE N GIVEN FAIRLY CHILLY LAKE SUPERIOR TEMPS OF 8-9C.
EXTENDED...WITH HI PRES AND MUCH DRIER AIR MOVING INTO THE GREAT LKS
EARLY NEXT WEEK...EXPECT DRY WX TO PREVAIL FROM MON THRU WED. MON IS
LIKELY TO BE RATHER COOL...BUT RETURN SW FLOW ON THE NW FLANK OF THE
HI SHIFTING TOWARD THE LOWER LKS WL BRING A WARMING TREND TUE THRU
WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 146 PM EDT THU SEP 18 2014
LOW-LEVEL MOISTURE WRAPPING AROUND THE BACKSIDE OF HIGH PRESSURE
OVER THE REGION WILL CONTINUE WITH MVFR CIGS AT IWD...AND BRING MVFR
CIGS TO CMX AND SAW OVERNIGHT THROUGH MUCH OF FRIDAY. AN INCREASING
PRESSURE GRADIENT ACROSS THE REGION WILL ALLOW FOR GUSTY S TO SSW
WINDS AT ALL SITES BEGINNING FRIDAY MORNING...ESPECIALLY AT SAW.
EXPECT GUSTS AS HIGH AS 30KTS DURING THE AFTERNOON HOURS. AN
APPROACHING LOW-LEVEL TROUGH IS EXPECTED TO BRING -SHRA TO WESTERN
UPPER MI DURING THE AFTERNOON...BUT ANY PRECIP SHOULD HOLD OFF AT
IWD OR CMX UNTIL AFTER 18Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...KLUBER
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
733 AM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 459 AM EDT THU SEP 18 2014
MAIN FCST CONCERN FOCUSES ON CHCS FOR SHRA FRI THRU SUN AS A SERIES
OF SHRTWVS IN A W-NW FLOW MOVE ACROSS THE UPPER GREAT LAKES REGION.
MODELS COMING INTO BETTER AGREEMENT SHOWING THE FIRST IN A SERIES OF
SHORTWAVES MOVING INTO THE NRN PLAINS ON FRI. STRENGTHENING WAA AND
INCREASINGLY MOIST SW FLOW AHEAD OF THIS SHORTWAVE AND ITS ASSOC
TROUGH/FRONTAL BOUNDARY OVER THE NRN PLAINS WILL INCREASE PWAT
VALUES TO 1.5 INCHES OR HIGHER (MORE THAN 180 PCT OF NORMAL) OVER
THE FCST AREA BY FRI AFTERNOON. MODEL SNDGS INDICATE 500-1000 J/KG
OF MUCAPE AND SHOWALTER INDICES DROPPING AS LOW AS -2 TO -4C BY FRI
AFTERNOON/FRI NIGHT SO WOULD EXPECT AN INCREASING POTENTIAL FOR
ELEVATED TSRA AS THE WARM FRONT APPROACHES LATE IN THE DAY. MODEL
CONSENSUS SUGGESTS THE BEST CHC FOR SHOWERS WL BE OVER THE W HALF
OF THE CWA FRI AFTERNOON AND OVER THE E HALF FRI EVNG...WHEN
ISENTROPIC ASCENT/H925-7 MSTR TRANSPORT AND DEEP LAYER Q-VECT CONV
WL BE MAXIMIZED OVER THOSE AREAS. AS FOR TEMPS...INCREASING CLD COVER
WL HOLD DOWN SFC HI TEMPS INTO THE 60S ON FRI DESPITE INFLUX OF MUCH
WARMER AIR. EXPECT RELATIVELY SMALL TEMP FALL ON FRI NGT WITH STRONG
SW FLOW AND INFLUX OF HIGHER PWAT.
SAT...ANOTHER STRONGER SHRTWV APPROACHING FROM SCNTRL CANADA AND THE
NRN PLAINS WILL PROPEL THE SFC LOW PRES TROUGH AND ASSOC COLD FNT
THRU THE UPR LAKES. THERE MAY BE A BETTER CHANCE OF SHOWERS/TS
AGAIN SAT AFTERNOON MAINLY OVER CENTRAL AND ERN COUNTIES AS DYNAMICS
WITH SHORTWAVE LOOK TO BE IN SYNC WITH DAYTIME HEATING AND TIMING OF
COLD FRONTAL PASSAGE. MLCAPES FCST IN EXCESS OF 1000 J/KG WOULD
SUPPORT THUNDER AND WITH DEEP LAYER SHEAR VALUES OF 45-50 KTS A FEW
STRONG TO POSSIBLY SVR STORMS WOULD NOT BE OUT OF THE QUESTION IF
INSTABILITY IS REALIZED. WILL MENTION THIS POTENTIAL IN HWO.
DEPENDING ON HOW QUICKLY THE SFC COLD FNT PASSES ON SAT AND
POTENTIAL BREAKS IN CLOUD COVER...SOME PLACES MAINLY OVER THE CNTRL
CWA COULD SEE TEMPS RISE WELL INTO THE 70S AS H85 TEMPS ARE FCST TO
PEAK AS HI AS 16-17C.
SAT NGT INTO SUN...ALTHOUGH MODELS SHOW TIMING DIFFERENCES...THEY
SEEM TO BE IN AGREEMENT THAT ADDITIONAL SHRTWVS WILL BE DROPPING
INTO THE GREAT LKS THAT ARE FCST TO DEEPEN AN UPR TROF OVER THE
REGION. THE RESULTING NW CYCLONIC FLOW OVER THE AREA ALONG WITH THE
PASSAGE OF A SECONDARY COLD FRONT SHOULD YIELD A GOOD DEAL OF CLD
COVER...PERIODS OF SHOWERS AND COOLER WX AS H85 TEMPS DROP FM AS HI
AS 15C ON SAT AFTN TO AS LO AS 2-4C BY LATE SUN. IT APPEARS
UNLIKELY THAT H85 TEMPS WL FALL ENOUGH TO REALIZE MUCH OF A LK
ENHANCED COMPONENT TO THE CLDS/SHOWERS SUN AND SUN NGT WITH WSHFT TO
THE N GIVEN FAIRLY CHILLY LAKE SUPERIOR TEMPS OF 8-9C.
EXTENDED...WITH HI PRES AND MUCH DRIER AIR MOVING INTO THE GREAT LKS
EARLY NEXT WEEK...EXPECT DRY WX TO PREVAIL FROM MON THRU WED. MON IS
LIKELY TO BE RATHER COOL...BUT RETURN SW FLOW ON THE NW FLANK OF THE
HI SHIFTING TOWARD THE LOWER LKS WL BRING A WARMING TREND TUE THRU
WED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 731 AM EDT THU SEP 18 2014
EXPECT MVFR LOW CLOUDS TO PERSIST UNTIL MID MORNING AT SAW WHEN WIND
EASTERLY WINDS OFF OF THE LAND BRING CLEARING. VFR CONDITIONS WILL
THEN BE THE RULE AT KSAW TODAY UNDER A DRY AIR MASS. AT KCMX...THE
MVFR CIG MAY LAST TOWARD NOON GIVEN THE AMOUNT OF UPSTREAM CLOUDS AND
UPSLOPE ESE FLOW OFF OF LAKE SUPERIOR. AT IWD...MVFR CIGS WILL GIVE
WAY TO CLEARING AS VEERING WINDS TO SE RESULT IN A DOWNSLOPE FLOW AND
DAYTIME HEATING/MIXING STRENGTHEN. VFR CONDITIONS WILL THEN PREVAIL
FOR THE REMAINDER OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT THU SEP 18 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN QUEBEC INTO THE ERN CONUS AND A RIDGE OVER THE ROCKIES RESULTING
IN NW FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...HIGH PRES WAS
CENTERED OVER NRN ONTARIO BRINGING LIGHT ENE ACROSS LAKE SUPERIOR
AND UPPER MI. THE SHALLOW INTRUSION OF COLD AIR BEHIND A COLD FRONT
INTO SRN WI HAS SHARPENED A 925 MB INVERSION AND TRAPPED ENOUGH LOW
LEVEL MOISTURE TO MAINTAIN EXTENSIVE CLOUD COVER ACROSS UPPER MI AND
NRN WI. IN ADDITION...MOISTENING FROM THE FLOW ACROSS LAKE
SUPERIOR... WITH SOME BANDING EVIDENT...HAS ALSO HELPED TO REINFORCE
THE CLOUDS. AS A RESULT...TEMPS ARE NOT EXPECTED TO DROP OFF ENOUGH
TO PRODUCE FROST OR FREEZING CONDITIONS.
TODAY...AS THE HIGH BUILDS TO THE SE AND WINDS VEER TO THE EAST
DAYTIME HEATING/MIXING WILL HELP ERODE THE LOW CLOUDS AND BRING
CLEARING BY THIS AFTERNOON. WITH 925 MB TEMPS REBOUNDING TO AROUND
6C...EXPECT MAX READINGS IN THE MID 50S EAST AND THE UPPER 50S SOUTH
AND WEST.
TONIGHT...SRLY FLOW WILL INCREASE FROM THE UPPER MS VALLEY TOWARD
THE WRN GREAT LAKES AS THE HIGH SHIFTS TO THE EAST AND LOW PRES
DEVELOPS FROM MANITOBA INTO THE PLAINS. ALTHOUGH THE STRONGER
MOISTURE INFLOW...ISENTROPIC LIFT AND RESULTING PCPN WILL REMAIN NW
OF THE CWA...MID/HIGH CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT FROM
WEST TO EAST. TEMPERATURES WILL ALSO REMAIN STEADY OR SLOWLY RISE
LATE. HOWEVER...THERE STILL MAY BE SOME PATCHY FROST OVER THE EAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 459 AM EDT THU SEP 18 2014
MAIN FCST CONCERN FOCUSES ON CHCS FOR SHRA FRI THRU SUN AS A SERIES
OF SHRTWVS IN A W-NW FLOW MOVE ACROSS THE UPPER GREAT LAKES REGION.
MODELS COMING INTO BETTER AGREEMENT SHOWING THE FIRST IN A SERIES OF
SHORTWAVES MOVING INTO THE NRN PLAINS ON FRI. STRENGTHENING WAA AND
INCREASINGLY MOIST SW FLOW AHEAD OF THIS SHORTWAVE AND ITS ASSOC
TROUGH/FRONTAL BOUNDARY OVER THE NRN PLAINS WILL INCREASE PWAT
VALUES TO 1.5 INCHES OR HIGHER (MORE THAN 180 PCT OF NORMAL) OVER
THE FCST AREA BY FRI AFTERNOON. MODEL SNDGS INDICATE 500-1000 J/KG
OF MUCAPE AND SHOWALTER INDICES DROPPING AS LOW AS -2 TO -4C BY FRI
AFTERNOON/FRI NIGHT SO WOULD EXPECT AN INCREASING POTENTIAL FOR
ELEVATED TSRA AS THE WARM FRONT APPROACHES LATE IN THE DAY. MODEL
CONSENSUS SUGGESTS THE BEST CHC FOR SHOWERS WL BE OVER THE W HALF
OF THE CWA FRI AFTERNOON AND OVER THE E HALF FRI EVNG...WHEN
ISENTROPIC ASCENT/H925-7 MSTR TRANSPORT AND DEEP LAYER Q-VECT CONV
WL BE MAXIMIZED OVER THOSE AREAS. AS FOR TEMPS...INCREASING CLD COVER
WL HOLD DOWN SFC HI TEMPS INTO THE 60S ON FRI DESPITE INFLUX OF MUCH
WARMER AIR. EXPECT RELATIVELY SMALL TEMP FALL ON FRI NGT WITH STRONG
SW FLOW AND INFLUX OF HIGHER PWAT.
SAT...ANOTHER STRONGER SHRTWV APPROACHING FROM SCNTRL CANADA AND THE
NRN PLAINS WILL PROPEL THE SFC LOW PRES TROUGH AND ASSOC COLD FNT
THRU THE UPR LAKES. THERE MAY BE A BETTER CHANCE OF SHOWERS/TS
AGAIN SAT AFTERNOON MAINLY OVER CENTRAL AND ERN COUNTIES AS DYNAMICS
WITH SHORTWAVE LOOK TO BE IN SYNC WITH DAYTIME HEATING AND TIMING OF
COLD FRONTAL PASSAGE. MLCAPES FCST IN EXCESS OF 1000 J/KG WOULD
SUPPORT THUNDER AND WITH DEEP LAYER SHEAR VALUES OF 45-50 KTS A FEW
STRONG TO POSSIBLY SVR STORMS WOULD NOT BE OUT OF THE QUESTION IF
INSTABILITY IS REALIZED. WILL MENTION THIS POTENTIAL IN HWO.
DEPENDING ON HOW QUICKLY THE SFC COLD FNT PASSES ON SAT AND
POTENTIAL BREAKS IN CLOUD COVER...SOME PLACES MAINLY OVER THE CNTRL
CWA COULD SEE TEMPS RISE WELL INTO THE 70S AS H85 TEMPS ARE FCST TO
PEAK AS HI AS 16-17C.
SAT NGT INTO SUN...ALTHOUGH MODELS SHOW TIMING DIFFERENCES...THEY
SEEM TO BE IN AGREEMENT THAT ADDITIONAL SHRTWVS WILL BE DROPPING
INTO THE GREAT LKS THAT ARE FCST TO DEEPEN AN UPR TROF OVER THE
REGION. THE RESULTING NW CYCLONIC FLOW OVER THE AREA ALONG WITH THE
PASSAGE OF A SECONDARY COLD FRONT SHOULD YIELD A GOOD DEAL OF CLD
COVER...PERIODS OF SHOWERS AND COOLER WX AS H85 TEMPS DROP FM AS HI
AS 15C ON SAT AFTN TO AS LO AS 2-4C BY LATE SUN. IT APPEARS
UNLIKELY THAT H85 TEMPS WL FALL ENOUGH TO REALIZE MUCH OF A LK
ENHANCED COMPONENT TO THE CLDS/SHOWERS SUN AND SUN NGT WITH WSHFT TO
THE N GIVEN FAIRLY CHILLY LAKE SUPERIOR TEMPS OF 8-9C.
EXTENDED...WITH HI PRES AND MUCH DRIER AIR MOVING INTO THE GREAT LKS
EARLY NEXT WEEK...EXPECT DRY WX TO PREVAIL FROM MON THRU WED. MON IS
LIKELY TO BE RATHER COOL...BUT RETURN SW FLOW ON THE NW FLANK OF THE
HI SHIFTING TOWARD THE LOWER LKS WL BRING A WARMING TREND TUE THRU
WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 124 AM EDT THU SEP 18 2014
LOW-LEVEL MOISTURE/CLOUDS BEHIND COLD FRONT THAT PASSED YESTERDAY
WILL CONTINUE TO BE AN ISSUE OVERNIGHT AT KSAW. WITH SOME MOISTURE
OFF LAKE SUPERIOR AND NORTHERLY UPSLOPE FLOW...EXPECT LOW CLOUDS TO
PERSIST UNTIL LATE IN THE NIGHT WHEN WINDS VEER MORE EASTERLY OFF
LAND. VFR CONDITIONS WILL THEN BE THE RULE AT KSAW TODAY UNDER A DRY
AIR MASS. AT KCMX...VFR CONDITIONS SHOULD PREVAIL OVERNIGHT...THOUGH
OCNL MVFR CIGS ARE NOT OUT OF THE QUESTION GIVEN SOME CLOUD COVER
STILL OVER LAKE SUPERIOR. A PERIOD OF MVFR CIGS IS MORE LIKELY
TOWARD DAYBREAK AND THRU MID MORNING AS WINDS VEER MORE EASTERLY AND
UPSLOPE OFF THE WARMER WATER OF KEWEENAW BAY. VFR CONDITIONS WILL
THEN PREVAIL LATE MORNING THRU AFTN AT KCMX. AT KIWD...MVFR CIGS
WILL SCATTER OUT OVERNIGHT AS WINDS VEER TO A DOWNSLOPE E TO SE
DIRECTION. VFR CONDITIONS WILL THEN PREVAIL FOR THE REMAINDER OF THE
FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT THU SEP 18 2014
AS HIGH PRES OVER NRN ONTARIO SHIFTS TOWARD NEW ENGLAND TODAY INTO
TONIGHT...WINDS WILL VEER TO THE S AND THEN INCREASE THROUGH THE DAY
ON FRI AS THE PRES GRADIENT SHARPENS BETWEEN THE DEPARTING HIGH AND
A TROUGH MOVING THRU SCENTRAL CANADA/NORTHERN PLAINS. SSW WINDS
COULD REACH 30 KTS...BUT HIGHER STABILITY OVER THE COLD LAKE
WATERS WILL LIMIT THE POTENTIAL FOR ANY GALES DESPITE THE STRENGTH
OF THE EXPECTED WINDS NOT FAR ABOVE THE WATER. WINDS WILL THEN
DIMINISH TO AROUND 20 KTS AND GRADUALLY VEER TO THE W-NW FOLLOWING A
COLD FRONTAL PASSAGE SAT BEFORE VEERING FURTHER TO THE N AND
INCREASING UP TO 25 KTS ON SUN/MON FOLLOWING THE PASSAGE OF A
REINFORCING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1100 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 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1100 PM CDT FRI SEP 19 2014
CONVECTION IS NOW EAST AND SOUTH OF THE TAF SITES LATE THIS
EVENING. A GROWING CONCERN OVERNIGHT IS HOW EXPANSIVE STRATUS AND
FOG WILL BECOME THAT HAS FORMED ACROSS PORTIONS OF CENTRAL MN
WHERE SKIES HAVE CLEARED AND WINDS HAVE BECOME LIGHT. THINKING IS
THAT CONDITIONS WILL ACTUALLY IMPROVE BY 09Z AS HIGH LEVEL CLOUDS
INCREASE ACROSS THE AREA ALONG WITH A COLD FRONTAL PASSAGE THAT
WILL BEGIN TO LOWER DEW POINTS. THERE COULD STILL BE SOME MVFR
CEILINGS DEVELOP NORTH AND EAST OF THE TWIN CITIES ON SATURDAY
WITH A VERY NEGATIVE CU RULE. A SECOND AND MUCH STRONGER COLD
FRONT IS SET TO BLAST SE ACROSS THE TAF SITES SATURDAY AFTERNOON.
A LINE OF CONVECTION IS STILL EXPECTED TO BE NEAR KAXN BY
21Z...KMSP AT 00Z AND KEAU BY 03Z. VERY STRONG WIND GUSTS MAY
OCCUR AS THE SHRA AND TSRA MOVE THROUGH. CONTINUED WITH TEMPO TSRA
AND NARROWED THE WINDOW DOWN TO 2 HOURS. WINDS BECOMING WNW NEAR
10 KNOTS OVERNIGHT AND NW 12-15 KNOTS ON SATURDAY. GUSTS WILL
REACH INTO THE 20 TO 25 KNOT RANGE.
KMSP...TEMPORARY BOUTS OF MVFR VSBYS ARE POSSIBLE EARLY THIS
MORNING AS SKY COVER DIMINISHES AND WINDS WEAKEN. INDICATED 6SM BR
BY 08Z THROUGH DAYBREAK. COLD FRONTAL PASSAGE BY DAYBREAK AS WELL
WITH NW WINDS 12-15 KNOTS THROUGH THE DAY. A SECOND AND STRONG
COLD FRONT WILL LIKELY BRING A LINE OF TSRA ACROSS THE AIRFIELD IN
THE 23Z-01Z TIME FRAME. THE STORMS MAY CONTAIN STRONG WIND GUSTS.
/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...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
721 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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 720 PM CDT FRI SEP 19 2014
MAIN CONCERN OVER THE NEXT FEW HOURS IS TSRA DEVELOPMENT FROM
SOUTH CENTRAL MN THROUGH THE SOUTH METRO AND INTO WEST CENTRAL WI.
VISIBLE IMAGERY SHOWING TOWERING CU FROM SOUTHWEST OF KMSP ON BACK
TO NORTH OF KFSD. AT THIS TIME...CONFIDENCE REMAINS HIGH THAT A
FEW STORMS WILL DEVELOP/MOVE INTO KEAU IN THE 01Z-04Z TIME FRAME.
KRWF...KMSP AND KRNH WILL SEE SOME LIGHT SHOWERS THIS EVENING AS A
BAND OF MID LEVEL FRONTOGENESIS MOVES THROUGH. PREVAILING
CONDITIONS EARLY TONIGHT WILL BE VFR. HOWEVER...LATE IN THE
NIGHT/EARLY SATURDAY MORNING IN THE WAKE OF A COLD FRONT...MVFR
CIGS/VSBYS ARE LIKELY FROM KSTC THROUGH KRNH AND KEAU. A VERY
NEGATIVE CU RULE IS SEEN ACROSS EASTERN MN AND WESTERN WI ON
SATURDAY. THE CONCERN IS THAT BKN-OVC MVFR CEILINGS MAY PERSIST
LONGER THAN CURRENTLY FORECAST FOR KSTC...KRNH AND KEAU. THEREFORE...
WITH CONFIDENCE NOT HIGH ON EXTENDING THE MVFR...USED BKN035-040.
ANOTHER COLD FRONT WILL BLAST THROUGH THE AREA SATURDAY AFTERNOON
AND EVENING. THIS FRONT WILL BE ACCOMPANIED BY VERY STRONG WINDS
ALOFT. SEVERAL CONVECTION ALLOWING MODELS INDICATE A BKN LINE OF
STORMS MOVING INTO KAXN AROUND 21Z. THE LINE HEADS SOUTHEAST AT
NEAR 50 KNOTS REACHING THE TWIN CITIES BY 23Z. CONFIDENCE IS
PRETTY HIGH ON THIS FEATURE AND USED TEMPO GROUPS FOR THE MN TAF
SITES AS THE LINE SHOULD NOT REACH INTO WESTERN WI UNTIL AFTER
21/00Z. THE STORMS THAT DO DEVELOP WILL HAVE THE CAPABILITY TO
PRODUCE STRONG TO SEVERE WIND GUSTS FROM THE NORTHWEST.
KMSP...STORM DEVELOPMENT THIS EVENING...IF IT OCCURS...WILL STAY
JUST SOUTH OF THE AIRFIELD. THERE WILL BE LIGHT SHOWERS MOVING
THROUGH FROM THE WNW. ANOTHER PERIOD FOR TSRA WILL BE LATE
SATURDAY AFTERNOON (23Z-02Z) WHEN A LINE OF STORMS IS EXPECTED TO
MOVE THROUGH AHEAD OF A STRONG COLD FRONT. LIGHT NNE WINDS EARLY
THIS EVENING WILL VEER TO THE SSW LATE IN THE EVENING THEN BECOME
NW 10-15 KNOTS SATURDAY MORNING.
/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...RAH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
816 PM CDT FRI SEP 19 2014
.UPDATE...
A COUPLE SHOWERS ARE STILL STRAGGLING ALONG DOWN NEAR THE HWY 84
CORRIDOR IN SW MS. EXPECT THESE TO BE GONE BY 03Z OR SO. THE SKY GRIDS
WERE UPDATED FOR OVERNIGHT BUT OTHERWISE SEE NO REASON TO MESS WITH
ANYTHING ELSE. PATCHY FOG IS POSSIBLE AGAIN IN THE MORNING HOURS
AROUND DAWN. /10/
&&
.AVIATION...
EXPECT VFR CONDITIONS TO PREVAIL THROUGH SATURDAY EVENING. GUIDANCE
HINTS AT BETTER LATE NIGHT AND EARLY MORNING FOG POTENTIAL OVER
EASTERN MS WHERE OCNL IFR/LIFR RESTRICTIONS APPEAR TO BE MORE
LIKELY...BUT AT LEAST MVFR CATEGORY RESTRICTIONS ARE POSSIBLE AT ALL
SITES. FOG WILL BURN OFF QUICKLY AFTER SUNRISE. /EC/
&&
.PREV DISCUSSION... /ISSUED 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 / 5 2 3 13
MERIDIAN 64 88 63 90 / 10 1 3 12
VICKSBURG 64 91 63 91 / 4 2 3 14
HATTIESBURG 67 91 67 91 / 10 3 2 12
NATCHEZ 67 89 66 90 / 10 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...UPDATED AVIATION
NWS ST LOUIS MO
1152 PM CDT Wed Sep 17 2014
.UPDATE:
Issued at 659 PM CDT Wed Sep 17 2014
Noticed some light returns on radar which looked a lot like
drizzle. Sure enough, light drizzle is now occurring here in Weldon
Spring. Looking at NAM X-sections and RAP soundings, seeing a
fairly deep layer of low level moisture between the surface and
about 800mb coincident with weak lift centered around 850mb.
This lift continues though at least 03Z, ending between 04Z-06Z.
Have therefore gone ahead and added patchy drizzle to the forecast
for this evening for most areas east of Columbia and south of
Bowling Green MO/Pittsfield IL.
Carney
&&
.SHORT TERM: (Through Late Tonight)
Issued at 311 PM CDT Wed Sep 17 2014
Old peripheral upper level energy from the MCS that is now pushing
into northern AR will continue to generate isolated-scattered
showers into the early evening before it either weakens too much to
generate anything or it exits our area to the east.
Otherwise, a warm frontal boundary over southeast KS and extreme
southwest MO, which has been nearly stationary due to the MCS rain,
will try to move northeast later tonight and should generate a new
round of SHRA/TSRA over areas mainly to the south and west of STL
metro. Thunder chances up our way look meager enough to leave out
for now.
Clouds are starting to break in southwest IL now and this trend
should continue and even quicken as the upper level energy
generating the showers there comes to an end or exits. This will
leave the leftover low cloud mainly to the west of the MS river and
the light easterly flow will begin to erode the eastern edge of
this, albeit slowly, this evening. By late tonight, though, a
favorable fog/stratus setup along the periphery of the surviving low
cloud in central-southeast MO may actually allow the leftovers to
grow a bit back to the east again.
Went with a more aggressive cooling on the IL side of the river
tonight due to expected clearing, while preferred the warmer MOS in
central MO. In-between, tended to favor the cooler MOS guidance as
well.
TES
.LONG TERM: (Thursday through Next Wednesday)
Issued at 311 PM CDT Wed Sep 17 2014
Surface ridge to continue building in on Thursday. Could see some
lingering light showers over far southern portions of forecast area
in the morning. Otherwise, clouds to clear out from northeast to
southwest with highs in the low 70s. Lows Thursday night will be in
the 50s.
By Friday, surface ridge moves off to the east allowing warmer
southerly flow to return to the region. However, next weather system
to move in on Saturday with showers and thunderstorms possible and
persist through Saturday night before tapering off on Sunday. Highs
on Friday will be in the mid to upper 70s, in the low to mid 80s on
Saturday, then begin to cool back down on Sunday as next ridge of
high pressure builds in.
Cooler weather to persist through the middle of next week with highs
in the 70s and lows in the 40s and 50s.
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1143 PM CDT Wed Sep 17 2014
MVFR flight conditions remain widespread from southwest IL across
eastern MO where they deteriorate to IFR across central and
western MO. Further north where skies cleared earlier, additional
fog and stratus is quickly developing. Conditions should deteriorate
overnight at KUIN and KCOU with dense fog/LIFR flight conditions
expected. For the St. Louis metro terminals I am expecting it to
remain status quo given the current t/td spreads and thus MVFR
flight conditions. All terminals should see improvement beginning
around 15z and then continued rising of ceiling heights and cloud
cover from late morning into the afternoon.
Specifics for KSTL:
Little change expected overnight with MVFR flight conditions
persisting. Anticipating improvement in cig heights beginning
around 15z, and then continued rising of ceiling heights and
reduction in cloud cover from late morning into the afternoon.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
332 PM MDT THU SEP 18 2014
.SHORT TERM...VALID FOR FRI AND SAT...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR TONIGHT
AND ISOLATED STRONG OR EVEN SEVERE STORMS ARE POSSIBLE THROUGH THE
MID EVENING HOURS.
AS OF MID AFTERNOON...THERE HAVE BEEN ENOUGH BREAKS IN CLOUD COVER
TO ENABLE TEMPERATURES IN THE 70S F BEHIND THE EARLIER SHOWERS AND
THUS MLCAPE VALUES HAVE RISEN TO 500-1000 J/KG IN SOUTHWESTERN AND
SOUTH CENTRAL MT PER RAP-BASED SPC MESOANALYSIS DATA. HEIGHT FALLS
HAVE CONTRIBUTED TO SEVERAL STORMS FROM THE ID PANHANDLE TO AROUND
LIVINGSTON AS OF 21 UTC. WE EXPECT FURTHER EXPANSION OF THAT STORM
ACTIVITY AS IT PROPAGATES EAST-NORTHEAST ACROSS THE AREA AND SO WE
ARE CARRYING LIKELY POPS ACROSS SOUTH CENTRAL MT AND NORTH CENTRAL
WY THIS EVENING. RECENT HRRR RUNS APPEAR TO MATCH THIS IDEA AND SO
WE LEANED TOWARD ITS SOLUTIONS TO BUILD THE EVENING FORECAST. SOME
RISK OF STRONG OR EVEN MARGINALLY SEVERE STORMS EXISTS WITH 0-6-KM
BULK SHEAR AROUND 40 KT. WELL-ORGANIZED...PERSISTENT CELLS WITH 50
DBZ HEIGHTS OVER 25 THOUSAND FEET AGL AND/OR BASE VELOCITIES OF 50
KT OR BETTER AT HEIGHTS UNDER 2000 FT AGL MAY NEED SEVERE THUNDER-
STORM WARNINGS...THOUGH WE NEED TO STRESS THAT WILL BE AN ISOLATED
OCCURRENCE AT MOST. A CHANCE OF SHOWERS AND WEAK STORMS WILL EXIST
OVER THE AREA AFTER MIDNIGHT TOO...BUT MAINLY IN SOUTHEASTERN MT.
A DRIER NORTHWEST FLOW ALOFT WILL TAKE OVER FRI AND BY SAT HEIGHTS
ALOFT WILL BE RISING STEADILY AS A RIDGE DEVELOPS OVER THE REGION.
WE ARE NOW ADVERTISING A DRY FORECAST IN MOST AREAS FRI EXCEPT FOR
THE MOUNTAINS AND IN FAR SOUTHEASTERN MT IN THE MORNING AS NONE OF
THE 12 UTC GUIDANCE SIMULATED ANY PRECIPITATION AND SOUNDINGS FROM
THOSE MODELS SHOWED STABLE PROFILES WITH A MID-LEVEL INVERSION. WE
EXPECT HIGHS NEAR 80 F FRI IN A WELL-MIXED AIR MASS AND IN THE 70S
F SAT WITH LIGHTER WINDS IN A MORE SHALLOW BOUNDARY LAYER. SCHULTZ
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
RELATIVELY WARM...LOW-KEY WEATHER IS EXPECTED FOR MUCH OF THE LONG
TERM FORECAST PERIOD AND WE ACCORDINGLY LEANED ON THE CONSENSUS OF
12 UTC GUIDANCE TO BUILD THE GRIDDED FORECAST DATABASE. WE DO HAVE
A CHANCE OF SHOWERS AND STORMS IN PLAY ACROSS NORTH CENTRAL WY AND
PARTS OF SOUTHERN MT SUN NIGHT THROUGH TUE IN RESPECT TO POTENTIAL
FOR A WEAK UPPER-LEVEL LOW MEANDERING ACROSS WY. GUIDANCE HAS BEEN
TRENDING A BIT NORTH WITH THAT FEATURE AND AN IN-HOUSE SET OF MOS-
BASED POP DATA SUPPORTED LOW-END PRECIPITATION CHANCES DURING THAT
TIME FRAME. HOWEVER...THE TRACK OF THE LOW IS QUESTIONABLE BECAUSE
IT WILL BE UNDERCUTTING MEAN RIDGING ALOFT WHICH ITSELF LOOKS LIKE
IT WILL MOVE EASTWARD WITH TIME AS A TROUGH BECOMES ESTABLISHED IN
THE PACIFIC NORTHWEST BY LATE IN THE WEEK. A WARMING TREND WILL BE
IN PLACE WITH WARM AIR ADVECTION AHEAD OF THAT TROUGH. SCHULTZ
&&
.AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS MUCH OF THE
REGION THIS AFTERNOON...AND ARE EXPECTED TO CONTINUE INTO
TONIGHT. MVFR TO IFR CONDITIONS CAN BE EXPECTED WITH THE
THUNDERSTORMS. OBSCURATION OVER AREA MOUNTAINS WILL CONTINUE INTO
TONIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CLEAR FROM WEST
TO EAST EARLY FRIDAY MORNING. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 059/080 052/075 049/076 053/075 054/077 054/078 054/079
61/B 10/U 00/U 12/T 22/T 11/U 12/T
LVM 051/078 043/077 043/076 047/077 049/078 048/079 049/079
61/N 10/U 00/U 12/T 22/T 21/B 22/T
HDN 058/082 050/077 045/078 052/078 052/078 052/080 052/081
61/B 10/U 00/U 12/T 22/T 11/U 12/T
MLS 061/082 051/075 045/076 052/078 054/076 053/079 053/081
42/T 00/U 00/U 01/U 12/T 21/U 11/B
4BQ 061/082 051/076 046/076 053/076 054/075 052/079 052/082
42/T 10/U 00/U 12/T 22/T 21/U 11/U
BHK 060/080 049/074 041/073 047/076 051/072 049/076 050/078
32/T 10/U 00/U 01/U 12/T 21/U 11/B
SHR 058/080 048/076 045/077 051/073 049/075 049/078 050/080
62/T 20/U 00/U 22/T 22/T 21/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1005 AM MDT THU SEP 18 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
UPDATE...ONLY TWEAK TO THE FORECAST THIS MORNING WAS TO INCREASE POPS
SOUTH OF THE MISSOURI RIVER GIVEN ONGOING PRECIP ACROSS SOUTH
CENTRAL MONTANA AND THE HRRR PROGGING SAID PRECIP THROUGH THE
AREA. REMAINDER OF FORECAST UNCHANGED. GILCHRIST
PREVIOUS DISCUSSION...UPPER RIDGE WILL BE FLATTENED TODAY BY A
WEAK SHORTWAVE MOVING ACROSS MONTANA. THIS WAVE WILL INTERACT WITH
A WARM AND UNSTABLE AIRMASS TO PRODUCE A FEW THUNDERSTORMS MAINLY
THIS AFTERNOON AND EVENING. A THERMAL RIDGE WILL ALLOW
TEMPERATURES TO RISE INTO THE 80S IN MOST AREAS... MAY SEE AN
ISOLATED 90 DEGREE HIGH IN THE SOUTH.
A COLD FRONT LATE TONIGHT AND FRIDAY MORNING ALONG WITH A
SHORTWAVE TROUGH ON ZONAL FLOW ALOFT WILL BRING A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS TONIGHT AND FRIDAY. NORTHWEST WINDS MAY
BE STRONG ENOUGH ON FRIDAY FOR A LAKE WIND ADVISORY ON FORT PECK
LAKE.
NORTHWEST FLOW ALOFT WILL BRING COOLER TEMPERATURES ON SATURDAY AS
A HIGH PRESSURE SYSTEM BUILDS INTO THE AREA WITH DRY WEATHER. FORRESTER
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
THERE SEEM TO BE THREE DIFFERENT FEATURES INTERACTING WITH EACH
OTHER THROUGH THE EXTENDED FORECAST PERIOD. FIRST IS THE RIDGE OF
HIGH PRESSURE. NEXT IS THE WEAK CLOSED LOW OR AREA OF WEAK LOW
PRESSURE UNDER THE RIDGE. THE THIRD IS THE LARGE LOW PRESSURE
TROUGH OFF THE WEST COAST OF U S AND CANADA.
MODEL AGREEMENT IS NEAR PERFECT FROM SATURDAY NIGHT THROUGH MONDAY
AFTERNOON KEEPING THE RIDGE OF HIGH PRESSURE OVER THE NORTHERN
HIGH PLAINS AND KEEPING OUR TEMPERATURES WARM AND WEATHER
CONDITIONS DRY.
STARTING MONDAY NIGHT...MODELS BEGIN TO SHOW SOME SLIGHT
DISAGREEMENTS. THE AREA OF WEAK LOW PRESSURE UNDER THE RIDGE VERY
SLOWLY EMERGES FROM THE CENTRAL ROCKIES TO OVER THE NORTHERN HIGH
PLAINS...BUT AS IT DOES SO...THE GFS DISSOLVES IT NEARLY
COMPLETELY EAST OF US BY WEDNESDAY MORNING WHILE THE EC MAINTAINS
IT AND PULLS IT DIRECTLY THROUGH NORTHEAST MONTANA THROUGH
WEDNESDAY AFTERNOON. CONSEQUENTLY...AS THIS MOISTURE APPROACHES
FROM THE SOUTHWEST...THE EC SHOWS A WETTER FORECAST FOR TUESDAY
NIGHT THROUGH WEDNESDAY WHILE THE GFS KEEPS THING DRY. AS THE
DISTURBANCE IS OVERALL WEAK...CHOSE TO BLEND THE TWO CAMPS HERE
AND KEEP THE FORECAST DRY WITH SUB-SLIGHT CHANCE POPS UNTIL
MODELS COME INTO BETTER AGREEMENT.
LASTLY...THE CHAOS ENSUES BEGINNING THURSDAY MORNING AS THE MODELS
TRY TO DEPICT SOME KIND OF PATTERN CHANGE AND LOW PRESSURE STORM
SYSTEM DIVING DOWN FROM THE CANADIAN ROCKIES. CHOSE TO INTRODUCE
SOME BROAD-BRUSHED SLIGHT CHANCE POPS GIVEN THE LIKELIHOOD OF THE
OVERALL PATTERN CHANGE...BUT DETAILS ARE OBVIOUSLY STILL
FORTHCOMING. THE GFS BRINGS DOWN A LARGE AND LONG-WAVE TROUGH
WHILE THE EC KEEPS A MORE NARROW TROUGH...EVENTUALLY CLOSING OFF
AN UPPER LOW AND SEPARATING FROM THE NORTHERN STREAM. WE WILL
LIKELY SEE SOME KIND OF A STRONG COLD FRONTAL SYSTEM APPROACHING
THE REGION BY THIS TIME NEXT WEEK. BMICKELSON
&&
.AVIATION...
FLIGHT CATEGORY: MAINLY VFR. IFR POSSIBLE.
SYNOPSIS: THE UPPER-LEVEL RIDGE IS TOPPLING AS AN UPPER-LEVEL
TROUGH ENTERS FROM THE WEST AND UNSETTLES THE WEATHER THROUGH THE
AFTERNOON HOURS.
SHOWERS & THUNDERSTORMS: SOME VICINITY SHOWERS ARE CURRENTLY
PLANNED AROUND KGDV DURING THE AFTERNOON AND EVENING HOURS. THE
OTHER TERMINALS HAVE A SLIGHT CHANCE FOR SHOWERS BUT CONFIDENCE IS
TOO LOW TO BE DIRECTLY IN THE TAFS. AMENDMENTS WILL BE NEEDED IF A
STRONGER STORM APPROACHES DURING THE AFTERNOON AND EVENING HOURS
WHICH COULD BRING PERIODS OF BRIEF IFR CONDITIONS.
AREA WINDS: SOUTHWEST 5 TO 15 KTS.
GAH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
104 PM CDT THU SEP 18 2014
.SYNOPSIS...
ISSUED AT 355 AM CDT THU SEP 18 2014
SURFACE LOW PRESSURE EXTENDS SOUTH FROM ALBERTA CANADA INTO
NEVADA AND WESTERN ARIZONA. SURFACE HIGH PRESSURE CENTER LOCATED
OVER THE NORTHERN GREAT LAKES. STRATUS IS DEVELOPING AND
EXPANDING FROM NWRN KS INTO SWRN NEBR AND THE SOUTHERN NEBRASKA
PANHANDLE EARLY THIS MORNING. PORTIONS OF CENTRAL AND SOUTHWEST
NEBRASKA REPORTING MAINLY LIGHT FOG 3-5SM WITH LOCALLY DENSE FOG
AT THE KBBW ASOS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU SEP 18 2014
NEAR TERM CONCERN IS DEVELOPMENT OF STRATUS AND FOG DEVELOPMENT
ACROSS PORTIONS OF CENTRAL AND SOUTHWEST NEBRASKA. WHILE LOW
VISIBILITY OF 1/4-1/2SM AT KBBW IS POSSIBLE ACROSS THE
AREA...PREVAILING VISIBILITIES SHOULD RANGE FROM 3-5 SM OR
HIGHER. AREAS TO PATCHY FOG IN THE FORECAST UNTIL 15Z.
OTHERWISE...STRATUS IS FORECAST TO QUICKLY EXPAND NORTHWESTWARD
INTO WESTERN NEBRASKA THIS MORNING. MODELS SHOW A NEARLY
SATURATED H9-H85 LAYER PRESENT WITH RELATIVELY DRY AIR ALOFT. THE
STRATUS IS FORECAST TO EXIT MUCH OF THE PANHANDLE BY 18Z...WHILE
POTENTIALLY PERSISTING OVER PORTIONS OF SWRN INTO CENTRAL
NEBRASKA THROUGH THE AFTERNOON. THIS AGREED UPON BY THE NAM AND
06Z RAP MODEL. THE GFS IS LESS AGGRESSIVE WITH CLOUDS WITH MUCH
HIGHER MOS GUIDANCE. USING 00Z SUPERBLEND OUTPUT...BLENDED WITH
THE 00Z MET GUIDANCE TO REFLECT COOLER HIGHS. WHERE CLEARING
OCCURS ACROSS WRN TIER OF COUNTIES...HIGHS IN THE UPPER 80S
ATTAINABLE. MID 70S FORECAST FOR PORTIONS OF CENTRAL AND SERN
ZONES. ALSO INCREASED PERCENT SKY COVER TO REFLECT MOSTLY CLOUDY
SKIES CENTRAL AND SERN ZONES.
STRONG WARM AIR ADVECTION TONIGHT WITH H85 TEMPS UP TO 25C. THIS
WILL CAUSE LINGERING STRATUS THIS EVENING TO QUICKLY LIFT
NORTHEAST AND DISPERSE AFTER 06Z. LOWS TONIGHT WILL BE MILDER
THAN THE PAST SEVERAL NIGHTS RANGING MAINLY IN THE LOWER 60S.
THERE WILL BE A STRONG INVERSION WITH SOUTH WINDS BECOMING
SOUTHWEST LATE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU SEP 18 2014
FRIDAY WILL BE AN UNSEASONABLE WARM DAY AS A LOW DEVELOPS OVER SW
S DAKOTA ALONG A COLD FRONT STRETCHED FROM THE NORTHERN PLAINS
INTO WYOMING. SOUTHERLY WINDS INCREASE AHEAD OF THE FRONT WHICH
SHOULD MIX OUT ANY BL MOISTURE FOG/STRATUS. 850 MB TEMPS INTO THE
20S C AND MOS GUIDANCE WELL INTO THE 80S AND EVEN SOME LOW 90S.
SHOULD SEE SOME A FEW HIGH CLOUDS FROM STORM SYSTEM TO THE SOUTH
SO KEEP HIGHS CONSERVATIVE. COLD FRONT WILL WILL PUSH ACROSS THE
AREA FRIDAY NIGHT INTO SATURDAY. SOME ELEVATED INSTABILITY
OVERNIGHT...WITH AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY. THE ADDED CLOUDS SHOULD KEEP TEMPS
MILD OVERNIGHT.
COOLER BEHIND THE FRONT WITH PRECIP EXPECTED TO BE PUSHING EAST
IN THE MORNING. SOME SUN BEHIND THE FRONT AND TEMPS REBOUND TO
AROUND 80 ON SATURDAY.
COOL HIGH PRESSURE BUILDS IN OVER THE REST OF THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPS TO SLOWLY TREND DOWN THROUGH MONDAY.
MEANWHILE A DISTURBANCE WILL RIDE ALONG THE FRONT RANGE...HOWEVER
MODELS GENERALLY KEEP PRECIP WEST OF THE CWA.
NEXT WEEK THE HIGH SLIDES EAST WITH RETURN SOUTHERLY FLOW TO
BRING A RETURN OF MORE MOISTURE. A DISTURBANCE SHOULD RIDE ACROSS
THE CENTRAL ROCKIES EARLY MONDAY WITH A CHANCE FOR PRECIP LIFTING
ACROSS THE CWA MONDAY INTO TUESDAY. ALTHOUGH 850 TEMPS ON THE
RISE...CLOUDS /ASSOCIATED WITH THE DISTURBANCE/ LIKELY TO KEEP
TEMPS FROM JUMPING UP TO MUCH. GUIDANCE SUGGEST SEASONAL MID
70S...WHICH SEEMS REASONABLE AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1254 PM CDT THU SEP 18 2014
AN AREA OF STRATUS AND ASSOCIATED MVFR AND LOCAL IFR WILL PERSIST
THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTH CENTRAL
NEBRASKA...SOUTHWARD INTO SOUTHWEST AND PORTIONS OF SOUTH CENTRAL
NEBRASKA. THIS WILL LOWER TONIGHT WITH POSSIBLE LIFR CONDITIONS IN
SPOTS. AS WINDS JUST ABOVE THE SURFACE BECOME SOUTHWEST LATE TONIGHT
AND FRIDAY MORNING...THE LOW CEILINGS SHOULD QUICKLY MOVE OUT OF THE
REGION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
700 AM CDT THU SEP 18 2014
.SYNOPSIS...
ISSUED AT 355 AM CDT THU SEP 18 2014
SURFACE LOW PRESSURE EXTENDS SOUTH FROM ALBERTA CANADA INTO
NEVADA AND WESTERN ARIZONA. SURFACE HIGH PRESSURE CENTER LOCATED
OVER THE NORTHERN GREAT LAKES. STRATUS IS DEVELOPING AND
EXPANDING FROM NWRN KS INTO SWRN NEBR AND THE SOUTHERN NEBRASKA
PANHANDLE EARLY THIS MORNING. PORTIONS OF CENTRAL AND SOUTHWEST
NEBRASKA REPORTING MAINLY LIGHT FOG 3-5SM WITH LOCALLY DENSE FOG
AT THE KBBW ASOS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU SEP 18 2014
NEAR TERM CONCERN IS DEVELOPMENT OF STRATUS AND FOG DEVELOPMENT
ACROSS PORTIONS OF CENTRAL AND SOUTHWEST NEBRASKA. WHILE LOW
VISIBILITY OF 1/4-1/2SM AT KBBW IS POSSIBLE ACROSS THE
AREA...PREVAILING VISIBILITIES SHOULD RANGE FROM 3-5 SM OR
HIGHER. AREAS TO PATCHY FOG IN THE FORECAST UNTIL 15Z.
OTHERWISE...STRATUS IS FORECAST TO QUICKLY EXPAND NORTHWESTWARD
INTO WESTERN NEBRASKA THIS MORNING. MODELS SHOW A NEARLY
SATURATED H9-H85 LAYER PRESENT WITH RELATIVELY DRY AIR ALOFT. THE
STRATUS IS FORECAST TO EXIT MUCH OF THE PANHANDLE BY 18Z...WHILE
POTENTIALLY PERSISTING OVER PORTIONS OF SWRN INTO CENTRAL
NEBRASKA THROUGH THE AFTERNOON. THIS AGREED UPON BY THE NAM AND
06Z RAP MODEL. THE GFS IS LESS AGGRESSIVE WITH CLOUDS WITH MUCH
HIGHER MOS GUIDANCE. USING 00Z SUPERBLEND OUTPUT...BLENDED WITH
THE 00Z MET GUIDANCE TO REFLECT COOLER HIGHS. WHERE CLEARING
OCCURS ACROSS WRN TIER OF COUNTIES...HIGHS IN THE UPPER 80S
ATTAINABLE. MID 70S FORECAST FOR PORTIONS OF CENTRAL AND SERN
ZONES. ALSO INCREASED PERCENT SKY COVER TO REFLECT MOSTLY CLOUDY
SKIES CENTRAL AND SERN ZONES.
STRONG WARM AIR ADVECTION TONIGHT WITH H85 TEMPS UP TO 25C. THIS
WILL CAUSE LINGERING STRATUS THIS EVENING TO QUICKLY LIFT
NORTHEAST AND DISPERSE AFTER 06Z. LOWS TONIGHT WILL BE MILDER
THAN THE PAST SEVERAL NIGHTS RANGING MAINLY IN THE LOWER 60S.
THERE WILL BE A STRONG INVERSION WITH SOUTH WINDS BECOMING
SOUTHWEST LATE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU SEP 18 2014
FRIDAY WILL BE AN UNSEASONABLE WARM DAY AS A LOW DEVELOPS OVER SW
S DAKOTA ALONG A COLD FRONT STRETCHED FROM THE NORTHERN PLAINS
INTO WYOMING. SOUTHERLY WINDS INCREASE AHEAD OF THE FRONT WHICH
SHOULD MIX OUT ANY BL MOISTURE FOG/STRATUS. 850 MB TEMPS INTO THE
20S C AND MOS GUIDANCE WELL INTO THE 80S AND EVEN SOME LOW 90S.
SHOULD SEE SOME A FEW HIGH CLOUDS FROM STORM SYSTEM TO THE SOUTH
SO KEEP HIGHS CONSERVATIVE. COLD FRONT WILL WILL PUSH ACROSS THE
AREA FRIDAY NIGHT INTO SATURDAY. SOME ELEVATED INSTABILITY
OVERNIGHT...WITH AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY. THE ADDED CLOUDS SHOULD KEEP TEMPS
MILD OVERNIGHT.
COOLER BEHIND THE FRONT WITH PRECIP EXPECTED TO BE PUSHING EAST
IN THE MORNING. SOME SUN BEHIND THE FRONT AND TEMPS REBOUND TO
AROUND 80 ON SATURDAY.
COOL HIGH PRESSURE BUILDS IN OVER THE REST OF THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPS TO SLOWLY TREND DOWN THROUGH MONDAY.
MEANWHILE A DISTURBANCE WILL RIDE ALONG THE FRONT RANGE...HOWEVER
MODELS GENERALLY KEEP PRECIP WEST OF THE CWA.
NEXT WEEK THE HIGH SLIDES EAST WITH RETURN SOUTHERLY FLOW TO
BRING A RETURN OF MORE MOISTURE. A DISTURBANCE SHOULD RIDE ACROSS
THE CENTRAL ROCKIES EARLY MONDAY WITH A CHANCE FOR PRECIP LIFTING
ACROSS THE CWA MONDAY INTO TUESDAY. ALTHOUGH 850 TEMPS ON THE
RISE...CLOUDS /ASSOCIATED WITH THE DISTURBANCE/ LIKELY TO KEEP
TEMPS FROM JUMPING UP TO MUCH. GUIDANCE SUGGEST SEASONAL MID
70S...WHICH SEEMS REASONABLE AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 700 AM CDT THU SEP 18 2014
VLIFR CONDITIONS AT KLBF SHOULD IMPROVE TO IFR AFTER 15Z. STRTUS
AND FOG HAS ALSO MOVED INTO KVTN PRIOR TO 12Z WITH IFR CONDITIONS
EXPECTED TO BECOME VFR BY 18Z. A RETURN TO IFR IS POSSIBLE BY 03Z
19TH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
356 AM CDT THU SEP 18 2014
.SYNOPSIS...
ISSUED AT 355 AM CDT THU SEP 18 2014
SURFACE LOW PRESSURE EXTENDS SOUTH FROM ALBERTA CANADA INTO
NEVADA AND WESTERN ARIZONA. SURFACE HIGH PRESSURE CENTER LOCATED
OVER THE NORTHERN GREAT LAKES. STRATUS IS DEVELOPING AND
EXPANDING FROM NWRN KS INTO SWRN NEBR AND THE SOUTHERN NEBRASKA
PANHANDLE EARLY THIS MORNING. PORTIONS OF CENTRAL AND SOUTHWEST
NEBRASKA REPORTING MAINLY LIGHT FOG 3-5SM WITH LOCALLY DENSE FOG
AT THE KBBW ASOS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU SEP 18 2014
NEAR TERM CONCERN IS DEVELOPMENT OF STRATUS AND FOG DEVELOPMENT
ACROSS PORTIONS OF CENTRAL AND SOUTHWEST NEBRASKA. WHILE LOW
VISIBILITY OF 1/4-1/2SM AT KBBW IS POSSIBLE ACROSS THE
AREA...PREVAILING VISIBILITIES SHOULD RANGE FROM 3-5 SM OR
HIGHER. AREAS TO PATCHY FOG IN THE FORECAST UNTIL 15Z.
OTHERWISE...STRATUS IS FORECAST TO QUICKLY EXPAND NORTHWESTWARD
INTO WESTERN NEBRASKA THIS MORNING. MODELS SHOW A NEARLY
SATURATED H9-H85 LAYER PRESENT WITH RELATIVELY DRY AIR ALOFT. THE
STRATUS IS FORECAST TO EXIT MUCH OF THE PANHANDLE BY 18Z...WHILE
POTENTIALLY PERSISTING OVER PORTIONS OF SWRN INTO CENTRAL
NEBRASKA THROUGH THE AFTERNOON. THIS AGREED UPON BY THE NAM AND
06Z RAP MODEL. THE GFS IS LESS AGGRESSIVE WITH CLOUDS WITH MUCH
HIGHER MOS GUIDANCE. USING 00Z SUPERBLEND OUTPUT...BLENDED WITH
THE 00Z MET GUIDANCE TO REFLECT COOLER HIGHS. WHERE CLEARING
OCCURS ACROSS WRN TIER OF COUNTIES...HIGHS IN THE UPPER 80S
ATTAINABLE. MID 70S FORECAST FOR PORTIONS OF CENTRAL AND SERN
ZONES. ALSO INCREASED PERCENT SKY COVER TO REFLECT MOSTLY CLOUDY
SKIES CENTRAL AND SERN ZONES.
STRONG WARM AIR ADVECTION TONIGHT WITH H85 TEMPS UP TO 25C. THIS
WILL CAUSE LINGERING STRATUS THIS EVENING TO QUICKLY LIFT
NORTHEAST AND DISPERSE AFTER 06Z. LOWS TONIGHT WILL BE MILDER
THAN THE PAST SEVERAL NIGHTS RANGING MAINLY IN THE LOWER 60S.
THERE WILL BE A STRONG INVERSION WITH SOUTH WINDS BECOMING
SOUTHWEST LATE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU SEP 18 2014
FRIDAY WILL BE AN UNSEASONABLE WARM DAY AS A LOW DEVELOPS OVER SW
S DAKOTA ALONG A COLD FRONT STRETCHED FROM THE NORTHERN PLAINS
INTO WYOMING. SOUTHERLY WINDS INCREASE AHEAD OF THE FRONT WHICH
SHOULD MIX OUT ANY BL MOISTURE FOG/STRATUS. 850 MB TEMPS INTO THE
20S C AND MOS GUIDANCE WELL INTO THE 80S AND EVEN SOME LOW 90S.
SHOULD SEE SOME A FEW HIGH CLOUDS FROM STORM SYSTEM TO THE SOUTH
SO KEEP HIGHS CONSERVATIVE. COLD FRONT WILL WILL PUSH ACROSS THE
AREA FRIDAY NIGHT INTO SATURDAY. SOME ELEVATED INSTABILITY
OVERNIGHT...WITH AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY. THE ADDED CLOUDS SHOULD KEEP TEMPS
MILD OVERNIGHT.
COOLER BEHIND THE FRONT WITH PRECIP EXPECTED TO BE PUSHING EAST
IN THE MORNING. SOME SUN BEHIND THE FRONT AND TEMPS REBOUND TO
AROUND 80 ON SATURDAY.
COOL HIGH PRESSURE BUILDS IN OVER THE REST OF THE WEEKEND INTO
EARLY NEXT WEEK WITH TEMPS TO SLOWLY TREND DOWN THROUGH MONDAY.
MEANWHILE A DISTURBANCE WILL RIDE ALONG THE FRONT RANGE...HOWEVER
MODELS GENERALLY KEEP PRECIP WEST OF THE CWA.
NEXT WEEK THE HIGH SLIDES EAST WITH RETURN SOUTHERLY FLOW TO
BRING A RETURN OF MORE MOISTURE. A DISTURBANCE SHOULD RIDE ACROSS
THE CENTRAL ROCKIES EARLY MONDAY WITH A CHANCE FOR PRECIP LIFTING
ACROSS THE CWA MONDAY INTO TUESDAY. ALTHOUGH 850 TEMPS ON THE
RISE...CLOUDS /ASSOCIATED WITH THE DISTURBANCE/ LIKELY TO KEEP
TEMPS FROM JUMPING UP TO MUCH. GUIDANCE SUGGEST SEASONAL MID
70S...WHICH SEEMS REASONABLE AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1143 PM CDT WED SEP 17 2014
ONCE AGAIN...THE FORECAST ISSUE TONIGHT AND EARLY THURSDAY IS THE
LIKELIHOOD OF CEILING AND/OR VISIBILITY BELOW INSTRUMENT
THRESHOLDS. CONSENSUS AMONG THE SHORT RANGE MODEL OUTPUT IS THAT
INSTRUMENT OR LOW INSTRUMENT METEOROLOGICAL CONDITIONS ARE LIKELY
IN A LARGE PART OF WESTERN NEBRASKA ALONG AND SOUTH-WEST OF A
VTN-ANW-BBW LINE. THOUGH IT MAKES LITTLE DIFFERENCE IN THE FLIGHT
CATEGORY...THE OTHER QUESTION IS...FOG OR STRATUS? CURRENT
INDICATIONS ARE THAT THE WIND SPEED WILL BE 5-10KT AND THAT WOULD
FAVOR LOW STRATUS VERSUS FOG. THEREFORE...OUR CONFIDENCE IS HIGH
THAT CEILING AT OR BELOW 500 FEET AGL WILL DEVELOP AFTER 09Z FOR
MHN...OGA AND LBF AND CONFIDENCE IS NOT HIGH THAT INSTRUMENT
CONDITIONS WILL DEVELOP FOR VTN...TIF AND BBW. FOR THIS FORECAST
ISSUANCE...WE WILL INCLUDE CEILING BELOW 500 FEET AND VISIBILITY
2-3SM FOR LBF AND CEILING JUST ABOVE 1000 FEET AGL AND VISIBILITY
3-5SM FOR VTN. THE LOW CLOUDS WILL BE SLOW TO SCATTER OUT.
CURRENT INDICATIONS FROM SHORT RANGE MODELS AND CONDITIONAL
CLIMATOLOGY WOULD INDICATE SCATTERING BETWEEN 16Z AND 18Z.
THOUGH THIS IS BEYOND THE 24 HOUR FORECAST WINDOW...INSTRUMENT
METEOROLOGICAL CONDITIONS ARE AGAIN POSSIBLE THURSDAY NIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...MASEK
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1003 AM PDT THU SEP 18 2014
.SYNOPSIS...SOUTHWEST FLOW AHEAD OF A LOW PRESSURE SYSTEM WILL
CONTINUE TO PUSH DRIER AIR INTO THE AREA. ENOUGH MOISTURE WILL STILL
BE IN PLACE FOR A CHANCE OF THUNDERSTORMS OVER MAINLY LINCOLN AND
MOHAVE COUNTIES TODAY. MOST OF THE AREA WILL BE DRY FRIDAY AS A
SOUTHWEST FLOW PERSISTS. SOUTHEAST FLOW WILL PULL MOISTURE BACK INTO
THE AREA OVER THE WEEKEND LEADING TO A CHANCE OF THUNDERSTORMS.
&&
.UPDATE...
DEWPOINTS CONTINUE TO DECREASE FROM WEST TO EAST AS DRY SOUTHWEST
FLOW PUSHES INTO THE REGION. ISOLATED TO SCATTERED THUNDERSTORM
DEVELOPMENT REMAINS POSSIBLE ACROSS LINCOLN...FAR EASTERN
CLARK...AND MOHAVE COUNTY THIS AFTERNOON AND EARLY EVENING /WHERE
LOW LEVEL MOISTURE LINGERS/. WITH LOSS OF HEATING EXPECT ANY
ACTIVITY TO DIMINISH RAPIDLY WITH A DRY OVERNIGHT ANTICIPATED. MADE
A FEW ADJUSTMENTS THIS MORNING TO QUICKLY TREND POPS DOWN THIS
EVENING AND DRY FOR ALL LOCATIONS OVERNIGHT...WHICH CORRELATES WELL
WITH THE 14Z AND 15Z RUNS OF THE HRRR AND OUR LOCAL HIRES MODELS.
&&
.PREVIOUS DISCUSSION...
317 AM PDT THU SEP 18 2014
.SHORT TERM...THROUGH FRIDAY NIGHT...AN UPPER TROUGH WILL MOVE INTO
NORTHERN CALIFORNIA TODAY WITH SOUTHWEST FLOW CONTINUING TO PUSH
DRIER AIR INTO OUR FORECAST AREA. THE MODELS...ESPECIALLY THE
NAM12...CONTINUE TO INDICATE A TONGUE OF PRETTY MOIST AND UNSTABLE
AIR AHEAD OF THIS DRY AIR WHICH WILL KEEP A CHANCE OF THUNDERSTORMS
TODAY OVER MAINLY LINCOLN AND MOHAVE COUNTIES. THE UPPER TROUGH IS
THEN FORECAST TO BECOME A CLOSED LOW JUST OFF THE CENTRAL CALIFORNIA
COAST BY FRIDAY WHILE SOUTHWEST FLOW BRINGS FURTHER DRYING TO OUR
FORECAST AREA. THERE MAY STILL BE JUST ENOUGH LINGERING MOISTURE FOR
A SLIGHT CHANCE OF THUNDERSTORMS FRIDAY OVER EASTERN PORTIONS OF
LINCOLN AND MOHAVE COUNTIES. CANNOT RULE OUT ISOLATED THUNDERSTORMS
OVER THE SIERRA FRIDAY AFTERNOON DUE TO THE PROXIMITY OF THE UPPER
LOW. TEMPERATURES WILL COOL TO NEAR NORMAL BY FRIDAY AS HEIGHTS FALL
DUE TO THE APPROACHING UPPER LOW.
.LONG TERM...MODELS IN GOOD AGREEMENT THAT AN UPPER LEVEL LOW WILL
BE SITUATED NEAR THE SOUTHERN CALIFORNIA COAST SATURDAY MORNING. AS
THE SLOW STARTS TO TRACK SLOWLY NORTHEAST ITS FORECAST TO START
PULLING MOISTURE INTO THE FORECAST AREA FROM SOUTHEAST ARIZONA BY
SATURDAY AFTERNOON. HOW MUCH MOISTURE WILL BE PULLED INTO THE AREA
IS STILL IN QUESTION...BUT HAVE GENERALLY INCLUDED SLIGHT CHANCE
POPS OVER THE ENTIRE REGION WITH THE BETTER CHANCES OVER THE SOUTH
AND EAST. CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE
SATURDAY NIGHT AND SUNDAY AS THE LOW AND ASSOCIATED DYNAMICS TRACKS
THROUGH THE AREA. HAVE UPPED POPS A BIT AS THE MODELS HAVE TRENDED
WETTER OVER THE COUPLE OF RUNS. TEMPERATURES WILL BE CLOSE TO NORMAL
WITH READINGS BELOW NORMAL IN AREAS OF THICKER CLOUD COVER.
THE LOW WILL CONTINUE TO TRACK NORTHEAST SUNDAY NIGHT AND MONDAY
WITH PRECIPITATION CHANCES ENDING ACROSS THE AREA WITH DRIER
CONDITIONS MOVING IN FROM THE WEST. THE SOUTHWEST FLOW WILL INCREASE
BY MONDAY AND TUESDAY AS A TROUGH DEVELOPS OFF THE COAST AND IN TURN
WILL BRING ABOVE NORMAL TEMPERATURES BACK INTO THE REGION.
&&
.AVIATION...FOR MCCARRAN...THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON
IN THE PEACH SPRINGS CORRIDOR WITH DRY AIR MOVING IN FROM THE WEST.
SIGNIFICANT CLOUD COVER IS NOT EXPECTED AT THE TERMINAL TODAY. SOUTH
WINDS UP TO 10 KTS EARLY THIS MORNING WILL TRANSITION TO
EAST/SOUTHEAST UNDER 8 KTS AFTER 14Z BEFORE BECOMING SOUTHWEST NEAR
15 KTS WITH GUSTS AROUND 20 KTS AFTER 21Z.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...LIGHT WINDS WILL BECOME SOUTH/SOUTHWEST 10-20 KTS BY
LATE MORNING OR EARLY AFTERNOON. GUSTS AROUND 25 KTS POSSIBLE IN
PORTIONS OF SOUTHEAST CALIFORNIA AND IN NYE COUNTY. DRY AIR WILL
CONTINUE TO PUSH IN FROM THE WEST TODAY BUT SCATTERED THUNDERSTORMS
ARE EXPECTED IN LINCOLN AND MOHAVE COUNTIES.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS
ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE...PADDOCK
SHORT TERM/AVIATION...HARRISON
LONG TERM...GORELOW
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
743 PM MDT FRI SEP 19 2014
.UPDATE...
UPDATED FORECAST TO LOWER PRECIPITATION CHANCES OVERNIGHT. MODELS CONTINUE
TO GENERATE LOTS OF QPF BUT SATELLITE AND RADAR IMAGERY INDICATING
NOT MUCH MORE THAN A FEW SHOWERS AND STORMS REMAIN OVER SERN NM.
INTERESTINGLY...A SMALL CLUSTER OF CONVECTION OVER THE SOUTHERN
SAN JUAN MOUNTAINS IN COLORADO CONTINUES TO DRIFT SWED TOWARD
THE CHAMA AREA. LEFT IN ISOLATED STORMS THROUGH THE EVENING
ALONG/NEAR THE COLORADO BORDER IN NORTH-CENTRAL NM AS A RESULT.
33
&&
.PREV DISCUSSION...536 PM MDT FRI SEP 19 2014...
.AVIATION...
00Z TAF CYCLE
ISOLD TSTMS CONTG NEAR THE AZ LINE...AND OVER THE EASTERN HALF OF
THE STATE THROUGH THIS EVENING...AS ODILE LEFTOVERS MOVE OFF INTO
THE TX PANHANDLE. PLENTY OF MOISTURE IN THE EAST WILL SUPPORT
BROAD AREAS OF EASTERN LOW CIGS AND FOG. SCT CLOUD GROUPS AND VCFG
IN EASTERN TAFS WILL SERVE AS PLACEHOLDERS FOR LOWEST EXPECTED CIG
EXCURSION DURING THE VALID PERIOD. DEEPENING SURFACE LOW PRESSURE
NEAR THE FOUR CORNERS THROUGH 00Z SAT AFTERNOON WILL BACK LOW
LEVEL WINDS TO EASTERLY...PROVIDING SUPPORT FOR UP SLOPE SHOWER
ENHANCEMENT AGAINST THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN
THROUGH THE OVERNIGHT AND MUCH OF SATURDAY.
SHY
&&
.PREV DISCUSSION...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 AREA WIDE.
&&
.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...UP SLOPE
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 AREA WIDE...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 AREA WIDE 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
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
536 PM MDT FRI SEP 19 2014
.AVIATION...
00Z TAF CYCLE
ISOLD TSTMS CONTG NEAR THE AZ LINE...AND OVER THE EASTERN HALF OF
THE STATE THROUGH THIS EVENING...AS ODILE LEFTOVERS MOVE OFF INTO
THE TX PANHANDLE. PLENTY OF MOISTURE IN THE EAST WILL SUPPORT
BROAD AREAS OF EASTERN LOW CIGS AND FOG. SCT CLOUD GROUPS AND VCFG
IN EASTERN TAFS WILL SERVE AS PLACEHOLDERS FOR LOWEST EXPECTED CIG
EXCURSION DURING THE VALID PERIOD. DEEPENING SURFACE LOW PRESSURE
NEAR THE FOUR CORNERS THROUGH 00Z SAT AFTERNOON WILL BACK LOW
LEVEL WINDS TO EASTERLY...PROVIDING SUPPORT FOR UP SLOPE SHOWER
ENHANCEMENT AGAINST THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN
THROUGH THE OVERNIGHT AND MUCH OF SATURDAY.
SHY
&&
.PREV DISCUSSION...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 AREA WIDE.
&&
.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...UP SLOPE
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 AREA WIDE...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 AREA WIDE 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
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1027 PM EDT FRI SEP 19 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING DRY WEATHER TO THE NORTH
COUNTRY TONIGHT...BUT TEMPERATURES WILL NOT BE AS COLD AS LAST
NIGHT. LOOKING FOR WARMER...WINDIER...AND WETTER CONDITIONS THIS
WEEKEND. HIGHS SATURDAY AND SUNDAY WILL BE IN THE 60S TO LOWER
70S. WINDS WILL BE INCREASING DURING THE DAY ON SATURDAY WITH
GUSTS IN THE 30 TO 40 MPH RANGE. EVENTUALLY RAIN WILL MOVE IN LATE
SATURDAY NIGHT AND ESPECIALLY THROUGHOUT THE DAY ON SUNDAY WITH
WIDESPREAD RAIN EXPECTED SUNDAY AFTERNOON AND NIGHT.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
AS OF 1027 PM EDT FRIDAY...MINOR ADJUSTMENTS TO HOURLY T/TD DATA
AS OF THE 10 O`CLOCK HOUR TO ACCOUNT FOR CURRENT OBSERVATIONAL
TRENDS. SOUTHERLY RETURN FLOW HAS COMMENCED WITH SOME
AREAS...PARTICULARLY THE CHAMPLAIN AND ST LAWRENCE VALLEYS HAVING
LIKELY ALREADY EXPERIENCED THEIR OVERNIGHT LOWS AS READINGS SLOWLY
CLIMB OVERNIGHT. OTHER AREAS HAVE DECOUPLED SO MORE OF A TYPICAL
DIURNAL TREND EXPECTED...NAMELY ERN VT AND PORTIONS OF THE
ADIRONDACKS. CASE IN POINT TRUSTY SARANAC LAKE ALREADY AT THE
FREEZING MARK. HAVE A GREAT NIGHT. PRIOR DISCUSSION FOLLOWS...
PRIOR DISCUSSION...
FORECAST REMAINS IN GOOD SHAPE AS WE PROGRESS INTO THE EVENING
HOURS. CLEAR SKIES WILL GRADUALLY GIVE WAY TO SOME HIGH CLOUDS
(ESPECIALLY NORTH) OVERNIGHT AS SURFACE HIGH PRESSURE SLIDES
OFFSHORE AS SOUTH/SOUTHWESTERLY RETURN FLOW BEGINS IN EARNEST
ALOFT...NOT AS MUCH AT THE SURFACE. NONETHELESS READINGS WILL BE
MILDER TONIGHT THAN LAST NIGHT GIVEN WARM THERMAL RESPONSE THROUGH
THE 925-850 MB LEVEL. STUCK CLOSE TO LATEST RAP 500 MB RH PROGS
WHICH APPEARS TO BE HANDLING THICKER MID LEVEL CLOUDS OFF TO OUR
NORTH...AND ITS SUBSEQUENT PROGRESSION RATHER WELL THIS EVENING.
LOWS REMAIN ON TRACK...RANGING FROM THE MID TO UPPER 30S IN ERN
VT...UPPER 30S TO LOWER 40S DACKS...AND SOLIDLY IN THE 40S FOR THE
CHAMPLAIN AND ST LAWRENCE VALLEYS.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 336 PM EDT FRIDAY...PRESSURE GRADIENT WILL CONTINUE TO
STRENGTHEN FROM THE SOUTH AND SOUTHWEST DURING THE DAY ON
SATURDAY. WHILE THIS WILL PROMOTE LOW LEVEL WARM AIR
ADVECTION...BREEZY TO WINDY CONDITIONS WILL DEVELOP. SO WHILE
HIGHS WILL BE IN THE MID 60S TO THE LOWER 70S...THE WINDS WILL NOT
ALLOW FOR IT TO FEEL THAT WARM WITH GUSTS IN THE 25 TO 35 MPH
RANGE AND EVEN SOME 40 MPH GUSTS IN THE SAINT LAWRENCE VALLEY. DRY
WEATHER IS EXPECTED DURING THE DAY ON SATURDAY...BUT THAT WILL
CHANGE AS AN UPPER LEVEL TROUGH OF LOW PRESSURE DEVELOPS OVER THE
UPPER MIDWEST. THIS FEATURE WILL BEGIN TO SHARPEN UP SATURDAY
NIGHT WHICH WILL ULTIMATELY SLOW THE ONSET OF THE PRECIPITATION
DOWN. CAN SEE A CHANCE OF SHOWERS LATE SATURDAY NIGHT OVER
NORTHERN NEW YORK...BUT THE STEADIER AND MORE WIDESPREAD SHOWERS
WILL NOT MOVE INTO THE ENTIRE AREA UNTIL LATER SUNDAY MORNING
THROUGH SUNDAY NIGHT. THE CLOUDS AND GUSTY WINDS SATURDAY NIGHT
WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL...SO IT WILL NOT TAKE
MUCH ON SUNDAY FOR HIGHS TO GET RIGHT BACK INTO THE MID 60S TO
LOWER 70S. THE UPPER TROUGH WILL BE SLOW TO MOVE EAST OF THE AREA
SUNDAY NIGHT...SO SHOWERS SHOULD BE FAIRLY WIDESPREAD SUNDAY
EVENING BEFORE GRADUALLY TAPERING OFF AFTER MIDNIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 336 PM EDT FRIDAY...NORTHWEST FLOW ALOFT WILL EXIST OVER THE
AREA MONDAY AND TUESDAY. THERE MAY BE SOME LINGERING SHOWERS
MONDAY MORNING...ESPECIALLY OVER VERMONT...BUT DRIER WEATHER IS
EXPECTED TO DEVELOP MONDAY AFTERNOON THROUGH TUESDAY. THE
NORTHWEST FLOW ALOFT WILL RESULT IN BELOW NORMAL HIGH
TEMPERATURES. LARGE UPPER LEVEL RIDGE BUILDS INTO THE REGION
WEDNESDAY THROUGH FRIDAY. THIS WILL RESULT IN A WARMING TREND WITH
HIGH TEMPERATURES AT OR ABOVE SEASONAL NORMALS THURSDAY AND
FRIDAY. DRY WEATHER WILL ALSO EXIST WEDNESDAY THROUGH FRIDAY.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
A HIGH PRESSURE AREA WILL CONTINUE TO SLIDE EAST OFF THE NEW
ENGLAND COAST OVERNIGHT. THIS WILL ALOW FOR SOUTHERLY SURFACE
WINDS TO DEVELOP ACROSS THE REGION OVERNIGHT INTO SATURDAY.
SATELLITE LOOP ALSO SHOWING HIGH CIRRUS CLOUDS WILL CONTINUE TO
STREAM EAST-SOUTHEAST FROM CANADA OVERNIGHT. MODEL GUIDANCE CONTINUES
TO HINT AT LOW LEVEL MOISTURE IN THE FORM OF LOW CLOUDS OVER THE
MID-ATLANTIC STATES WILL MOVE NORTH INTO THE REGION OVERNIGHT AND SATURDAY.
THUS...HAVE PUT IN A VFR LOW CLOUD DECK ACROSS THE REGION BETWEEN
08Z-12Z SATURDAY. SURFACE PRESSURE GRADIENT TO TIGHTEN OVERNIGHT
AND DURING THE DAY ON SATURDAY. THIS WILL RESULT IN SOUTH TO
SOUTHWEST SURFACE WINDS GUSTING TO 20 TO 30 KNOTS DEVELOPING
BETWEEN 10Z-14Z SATURDAY AND CONTINUING THROUGH 00Z SUNDAY.
OUTLOOK 00Z SATURDAY THROUGH WEDNESDAY...
00Z SUNDAY THROUGH 00Z WEDNESDAY...VFR-MVFR CEILINGS DEVELOP
SATURDAY NIGHT WITH RAIN MOVING IN...ESPECIALLY ON SUNDAY.
LOOKING AT MVFR CEILINGS AND VISIBILITIES WITH THE RAIN MOVING IN
WITH PRECIPITATION COMING TO AN END LATE SUNDAY NIGHT...BUT MVFR
CEILINGS PERSIST. EVENTUALLY LOOKING AT A RETURN TO VFR CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY AS HIGH PRESSURE BUILDS
INTO THE REGION.
&&
.MARINE...
STRONG SOUTH TO SOUTHWEST WINDS WILL DEVELOP AFTER MIDNIGHT TONIGHT AND
CONTINUE RIGHT INTO SUNDAY MORNING. SPEEDS WILL INCREASE INTO THE
20 TO 30 KNOT RANGE DURING THIS TIME PERIOD WITH GUSTS AS HIGH AS
35 KNOTS SATURDAY NIGHT AND SUNDAY MORNING. WAVES WILL BUILD INTO
THE 2 TO 5 FOOT RANGE MAKING FOR ROUGH BOATING CONDITIONS FOR A
GOOD PART OF THE WEEKEND. AS A RESULT...A LAKE WIND ADVISORY IS IN
EFFECT FROM MIDNIGHT TONIGHT RIGHT THROUGH SUNDAY MORNING.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...JMG
SHORT TERM...EVENSON
LONG TERM...EVENSON
AVIATION...WGH/EVENSON
MARINE...EVENSON
AREA FORECAST DISCUSSION
NWS RALEIGH NC
224 PM EDT THU SEP 18 2014
.SYNOPSIS...HIGH PRESSURE CENTERED NORTHEAST OF THE GREAT LAKES WILL
EXTEND DOWN THROUGH VIRGINIA AND THE CAROLINAS THROUGH THE
WEEKEND... AS IT SLIDES EAST. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST LATE SUNDAY... THEN MOVE SOUTHEAST THROUGH THE REGION
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 220 PM THURSDAY...
THROUGH TONIGHT: QUIET AND DRY NIGHT FOR MOST. SURFACE MAP SHOWS A
WEAK MSLP PATTERN OVER NC WITH A WEAK INVERTED TROUGH OVER THE WRN
PIEDMONT... HELPING TO FOCUS MOISTURE IN THE LOWEST 5-6 THOUSAND FT
IN THIS AREA AND FOSTERING DEVELOPMENT OF VERY ISOLATED SHALLOW
SHOWERS. THESE SHOULD PERSIST INTO THE EVENING HOURS... GIVEN THIS
WEAK LOW LEVEL MASS CONVERGENCE IN CONJUNCTION WITH WEAK TERRAIN
UPGLIDE... BUT WITH A CAPPING INVERSION EVIDENT AT 775-750 MB AND
WARM/DRY/STABLE AIR ABOVE... EXPECT DEVELOPMENT TO BE STUNTED BOTH
VERTICALLY AND IN COVERAGE... AS PW REMAINS BELOW NORMAL. THE LATEST
SEVERAL HRRR RUNS SUPPORT THIS AS WELL. WILL KEEP AN ISOLATED SHOWER
CHANCE IN THE WRN AND EXTREME SW CWA THROUGH THE EVENING.
OTHERWISE... FORECAST SOUNDINGS SHOW THE LOW LEVEL MOISTURE
GRADUALLY DISPERSING WITH TIME... STILL GREATER OVER THE WRN CWA
THAN IN THE EAST... SO EXPECT MOSTLY CLEAR SKIES EAST AND PARTLY
CLOUDY WEST. SLOWLY LOWERING SURFACE DEWPOINTS SHOULD LOWER THE RISK
OF FOG... EXCEPT PERHAP IN THE WRN CWA NEAR THE SURFACE TROUGH.
BASED ON LAST NIGHT`S LOWS AND STATISTICAL GUIDANCE... EXPECT LOWS
OF 58-63.
FOR FRI/FRI NIGHT: RAIN CHANCES WILL REMAIN LOW. THE MID LEVEL
TROUGH AXIS IS EXPECTED TO BE SHIFTING TO OUR SE WITH RISING HEIGHTS
ALOFT. LOW LEVEL MOISTURE TRANSPORT PERSISTS BUT IS CONFINED TO THE
FAR SRN AND SE CWA... WHERE PW VALUES WILL HOVER NEAR 1.4-1.5". THE
ONSHORE-DIRECTED LOW LEVEL STEERING FLOW COULD DRAW SHALLOW SEA
BREEZE SHOWERS INLAND OVER THE FAR SE CWA. ISOLATED UPSLOPE-
SUPPORTED SHOWERS REMAIN POSSIBLE IN THE FAR WRN CWA AS WELL. IN
GENERAL HOWEVER... THE TRADITIONAL MODELS REMAIN TOO WET... SHOWING
PRECIP COVERING THE MAJORITY OF THE CWA... WHICH APPEARS UNLIKELY
GIVEN THE LACK OF FORCING AND INSTABILITY WITH LIMITED MOISTURE.
WILL KEEP ISOLATED POPS ALONG THE WRN/SRN AND SE EDGES OF THE CWA
FRI AFTERNOON INTO THE EVENING. THICKNESSES ARE EXPECTED TO DIP
SLIGHTLY... INDICATING HIGHS OF 76-81. LOWS 56-61 WITH PARTLY CLOUDY
SKIES WEST AND MOSTLY CLEAR EAST. -GIH
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 224 PM THURSDAY...
SATURDAY AND SATURDAY NIGHT: HEIGHTS ALOFT WILL CONTINUE TO RISE
OVER THE CAROLINAS ON SATURDAY...AS AN EXTENSION OF THE MID LEVEL
RIDGE CENTERED OVER THE CENTRAL US RIDGE NOSES NORTHEASTWARD INTO
THE AREA...SANDWICHED BETWEEN THE AMPLIFYING NORTHERN STREAM DIVING
SEWD OUT OF SOUTHERN CANADA AND THE REMNANT LOW ALONG THE SOUTHEAST
COAST. AT THE SURFACE...DRY AIR SURFACE RIDGE AXIS WILL WEDGE
SOUTHWESTWARD DOWN THE MID ATLANTIC STATES AND THROUGH THE CAROLINAS
AND GEORGIA. RESULTANT LOW PWATS AND A STABLE AIR COLUMN WILL SECURE
DRY CONDITIONS. HIGHS IN THE UPPER 70S TO LOWER 80S. LOWS SATURDAY
NIGHT UPPER 50S TO LOWER 60S.
SUNDAY: AMPLIFYING/DIGGING NORTHERN STREAM TROUGH AND ASSOCIATED
POLAR WESTERLIES WILL PICK UP THE LINGERING AREA OF LOW PRESSURE
NEAR THE SOUTHEAST COAST AND KICK IT EAST-NORTHEASTWARD...LIFTING UP
THE NC COAST AND THEN OUT INTO THE ATLANTIC ON SUNDAY. LITTLE TO NO
SENSIBLE WEATHER IMPACTS ARE EXPECTED FROM THIS FEATURE...BUT A PRE-
FRONTAL TROUGH IS EXPECTED TO DEVELOP IN THE LEE OF THE MOUNTAINS
SUNDAY AFTERNOON...OWING TO THE APPROACH OF THE NORTHERN STREAM
TROUGH. WOULD NOT BE SURPRISED TO SEE AN ISOLATED SHOWER DEVELOP
INVOF OF THIS TROUGH...BUT WILL KEEP FORECAST DRY. SUNDAY LOOKS TO
BE THE WARMEST DAY IN THE NEXT FORESEEABLE FUTURE WITH LOW-LEVEL
THICKNESSES PROJECTED TO CLIMB 20 METERS ABOVE NORMAL...HIGHS IN THE
LOWER TO MID 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 224 PM THURSDAY...
SUNDAY NIGHT THROUGH MONDAY: 40 TO 60 METER HEIGHT FALLS TRAVERSING
THE REGION IN ADVANCE OF THE AMPLIFYING NORTHER STREAM TROUGH
ADVANCING EASTWARD INTO THE EASTERN US WILL DRIVE A SURFACE COLD
FRONT INTO THE AREA LATE SUNDAY NIGHT/EARLY MONDAY MORNING . WRT THE
COLD FRONTAL PASSAGE ON MONDAY...THE GFS HAS TRENDED TOWARDS THE
FASTER SOLUTION OF THE EC...WHICH HAS THE FRONT SOUTH AND EAST OF
THE AREA BY 18Z MONDAY. GIVEN THE FASTER TIMING...SUFFICIENT
INSTABILITY WILL BE LACKING AND GIVEN LIMITED MOISTURE
AVAILABILITY...CONVECTIVE/RAIN CHANCES REMAIN UNIMPRESSIVE. WILL
LEAVE IN SLIGHT CHANCE POPS...BUT FROPA COULD END BEING A NON-
MEASURABLE/SPRINKLE EVENT FOR MUCH OF THE CWA. FASTER FROPA WILL
RESULT IN SLIGHTLY COOLER TEMPERATURES MONDAY AFTERNOON. HIGHS IN
THE UPPER 70S NW TO LOWER 80S SE.
TUESDAY THROUGH THURSDAY: LIKE CLOCKWORK...A STRONG +1030MB CANADIAN
SURFACE HIGH... ANCHORED UNDERNEATH THE UPPER CONFLUENCE ZONE IN THE
WAKE OF THE EXITING UPPER TROUGH/CLOSED LOW OVER SOUTHERN NEW
ENGLAND...WILL PROVIDE THE FIRST DAYS OF FALL(AUTUMNAL EQUINOX
BEGINS MONDAY SEPT 22 AT 10:29 PM EDT)WITH BONA FIDE FALL
CONDITIONS. DRY WITH TEMPERATURES 5-8 DEGREES BELOW NORMAL. HIGHS 70
TO 75. LOWS IN THE LOWER TO MID 50S...WITH SOME UPPER 40S POSSIBLE
WEDNESDAY NIGHT ACROSS THE NORTHERN PIEDMONT.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 145 PM THURSDAY...
VFR CONDITIONS ARE LIKELY TO HOLD THROUGH THE TAF FORECAST PERIOD.
EARLIER MVFR CIGS AT INT/GSO HAVE MIXED OUT TO SCATTERED... ALTHOUGH
THESE MAY STILL GO BROKEN BRIEFLY PRIOR TO 20Z. OTHERWISE... ANY
CLOUDS THROUGH TONIGHT AND FRI MORNING SHOULD BE BASED ABOVE 3 000
FT AGL... MORE LIKELY TO BE BROKEN AT INT/GSO WITH LESS COVERAGE AT
RDU/RWI/FAY. LIGHT AND VARIABLE WINDS MAINLY FROM THE NE WILL
CONTINUE TONIGHT AT SPEEDS MAINLY UNDER 6 KTS... THEN SHOULD
INCREASE TO 7-10 KTS FROM THE ENE AFTER 14Z FRI.
LOOKING BEYOND 18Z FRI... VFR CONDITIONS SHOULD DOMINATE THROUGH AT
LEAST SUNDAY... ALTHOUGH MVFR FOG IS POSSIBLE EARLY SAT MORNING AS
THE LIGHT ONSHORE LOW LEVEL FLOW PERSISTS. A PERIOD OF MVFR CIGS IS
POSSIBLE LATE SUN INTO SUN NIGHT AHEAD OF A COLD FRONT. VFR
CONDITIONS SHOULD THEN RETURN FOR MON/TUE WITH HIGH PRESSURE
BUILDING IN FROM THE NW. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 PM EDT THU SEP 18 2014
.SYNOPSIS...HIGH PRESSURE CENTERED NORTHEAST OF THE GREAT LAKES WILL
EXTEND DOWN THROUGH VIRGINIA AND THE CAROLINAS THROUGH THE
WEEKEND... AS IT SLIDES EAST. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST LATE SUNDAY... THEN MOVE SOUTHEAST THROUGH THE REGION
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 220 PM THURSDAY...
THROUGH TONIGHT: QUIET AND DRY NIGHT FOR MOST. SURFACE MAP SHOWS A
WEAK MSLP PATTERN OVER NC WITH A WEAK INVERTED TROUGH OVER THE WRN
PIEDMONT... HELPING TO FOCUS MOISTURE IN THE LOWEST 5-6 THOUSAND FT
IN THIS AREA AND FOSTERING DEVELOPMENT OF VERY ISOLATED SHALLOW
SHOWERS. THESE SHOULD PERSIST INTO THE EVENING HOURS... GIVEN THIS
WEAK LOW LEVEL MASS CONVERGENCE IN CONJUNCTION WITH WEAK TERRAIN
UPGLIDE... BUT WITH A CAPPING INVERSION EVIDENT AT 775-750 MB AND
WARM/DRY/STABLE AIR ABOVE... EXPECT DEVELOPMENT TO BE STUNTED BOTH
VERTICALLY AND IN COVERAGE... AS PW REMAINS BELOW NORMAL. THE LATEST
SEVERAL HRRR RUNS SUPPORT THIS AS WELL. WILL KEEP AN ISOLATED SHOWER
CHANCE IN THE WRN AND EXTREME SW CWA THROUGH THE EVENING.
OTHERWISE... FORECAST SOUNDINGS SHOW THE LOW LEVEL MOISTURE
GRADUALLY DISPERSING WITH TIME... STILL GREATER OVER THE WRN CWA
THAN IN THE EAST... SO EXPECT MOSTLY CLEAR SKIES EAST AND PARTLY
CLOUDY WEST. SLOWLY LOWERING SURFACE DEWPOINTS SHOULD LOWER THE RISK
OF FOG... EXCEPT PERHAP IN THE WRN CWA NEAR THE SURFACE TROUGH.
BASED ON LAST NIGHT`S LOWS AND STATISTICAL GUIDANCE... EXPECT LOWS
OF 58-63.
FOR FRI/FRI NIGHT: RAIN CHANCES WILL REMAIN LOW. THE MID LEVEL
TROUGH AXIS IS EXPECTED TO BE SHIFTING TO OUR SE WITH RISING HEIGHTS
ALOFT. LOW LEVEL MOISTURE TRANSPORT PERSISTS BUT IS CONFINED TO THE
FAR SRN AND SE CWA... WHERE PW VALUES WILL HOVER NEAR 1.4-1.5". THE
ONSHORE-DIRECTED LOW LEVEL STEERING FLOW COULD DRAW SHALLOW SEA
BREEZE SHOWERS INLAND OVER THE FAR SE CWA. ISOLATED UPSLOPE-
SUPPORTED SHOWERS REMAIN POSSIBLE IN THE FAR WRN CWA AS WELL. IN
GENERAL HOWEVER... THE TRADITIONAL MODELS REMAIN TOO WET... SHOWING
PRECIP COVERING THE MAJORITY OF THE CWA... WHICH APPEARS UNLIKELY
GIVEN THE LACK OF FORCING AND INSTABILITY WITH LIMITED MOISTURE.
WILL KEEP ISOLATED POPS ALONG THE WRN/SRN AND SE EDGES OF THE CWA
FRI AFTERNOON INTO THE EVENING. THICKNESSES ARE EXPECTED TO DIP
SLIGHTLY... INDICATING HIGHS OF 76-81. LOWS 56-61 WITH PARTLY CLOUDY
SKIES WEST AND MOSTLY CLEAR EAST. -GIH
&&
.SHORT TERM / /...
AS OF 310 AM THURSDAY...
TO BE UPDATED.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
A PORTION OF THE LONGWAVE TROUGH INITIALLY ALONG THE EAST COAST WILL
BE LEFT BEHIND AND SUPPORT WEAK FRONTAL WAVE DEVELOPMENT OFFSHORE
THE SE US COAST THIS WEEKEND...BUT THE OTHERWISE DEAMPLIFYING/LIFTING
TROUGH WILL YIELD TO RISING HEIGHTS ALOFT OVER THE CAROLINAS...AS A
FLAT MID LEVEL RIDGE RIDGE NOSES EASTWARD FROM THE SOUTHERN PLAINS
AND LOWER MS VALLEY. THE RE-ESTABLISHMENT AND AMPLIFICATION OF A
WESTERN NOAM RIDGE WILL THEN RESULT IN DOWNSTREAM TROUGH
AMPLIFICATION FROM SOUTH-CENTRAL CANADA TO THE EAST-CENTRAL US THIS
WEEKEND-EARLY NEXT WEEK. THE WESTERN RIDGE...IN PROGRESSIVE FLOW
ALOFT...WILL BUILD EAST ACROSS THE MID-LATITUDES OF THE CENTRAL AND
EASTERN STATES MID TO LATE NEXT WEEK.
BENEATH THE CONTINUED RISING HEIGHTS ALOFT SAT...A CANADIAN SFC HIGH
(AROUND 1030 MB) WILL BUILD FROM CENTRAL CANADA TO THE CANADIAN
MARITIMES AND RIDGE SOUTH/SOUTHWESTWARD THROUGH THE EASTERN STATES
THROUGH THE FIRST HALF OF THE WEEKEND...BEFORE YIELDING - AMIDST
FALLING HEIGHTS DOWNSTREAM OF THE AFOREMENTIONED REDEVELOPING TROUGH
ALOFT HEADED FOR THE EAST-CENTRAL US - TO APPALACHIAN-LEE SFC TROUGH
DEVELOPMENT SUN...AND A PASSING COLD FRONT MON. ANOTHER STRONG
CANADIAN HIGH WILL EXPAND AND STRENGTHEN ACROSS MUCH OF THE CENTRAL
AND EASTERN CONUS IN THE WAKE OF THE PASSING COLD FRONT...WHICH
GUIDANCE SUGGESTS WILL CLEAR ALL BUT PERHAPS SOUTHERN FL BY MID NEXT
WEEK.
WITH THE BRUNT OF THE COOLER AND DRIER AIR ASSOCIATED WITH THE LEAD
HIGH LIKELY TO HOLD OVER THE NORTHERN MIDDLE ATLANTIC AND NORTHEAST
STATES THIS WEEKEND...CENTRAL NC TEMPERATURES ARE APT TO WARM TO ABOVE
AVG...IN THE LOWER TO MIDDLE 80S - WARMEST SUNDAY. ANY SIGNIFICANT
LOW-MID LEVEL CLOUD COVER ATTENDING THE OFFSHORE FRONTAL WAVE IS
FORECAST AT THIS TIME TO HOLD ALONG COASTAL AREAS...WITH MORE OF A
NORTHWESTERLY FLOW COMPONENT OVER CENTRAL NC...INTO THE OFFSHORE
LOW/FRONTAL ZONE.
FRONTAL PASSAGE TIMING HAS SPED FOR MON...SUCH THAT A FEW LINGERING
SHOWERS FROM UPSTREAM CONVECTION MAY DRIFT INTO THE NW PIEDMONT SUN
NIGHT...AND LEAVE MAINLY THE FAR SOUTHEAST CWFA IN THE WARM SECTOR
THROUGH EARLY AFTERNOON...WITH EARLIER/UNFAVORABLE DIURNAL FRONTAL
TIMING ACROSS THE REMAINDER OF THE AREA. SHOWER CHANCES WILL BE
RELATIVELY LOW...THROUGHOUT THIS PERIOD...HOWEVER...AS GULF MOISTURE
RETURN WILL BE LIMITED. COOLER TUE-WED...WITH HIGHS IN THE 70S IN
THE POST-FRONTAL CANADIAN HIGH...WITH SFC DEWPOINTS IN THE 40S-50S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 145 PM THURSDAY...
VFR CONDITIONS ARE LIKELY TO HOLD THROUGH THE TAF FORECAST PERIOD.
EARLIER MVFR CIGS AT INT/GSO HAVE MIXED OUT TO SCATTERED... ALTHOUGH
THESE MAY STILL GO BROKEN BRIEFLY PRIOR TO 20Z. OTHERWISE... ANY
CLOUDS THROUGH TONIGHT AND FRI MORNING SHOULD BE BASED ABOVE 3 000
FT AGL... MORE LIKELY TO BE BROKEN AT INT/GSO WITH LESS COVERAGE AT
RDU/RWI/FAY. LIGHT AND VARIABLE WINDS MAINLY FROM THE NE WILL
CONTINUE TONIGHT AT SPEEDS MAINLY UNDER 6 KTS... THEN SHOULD
INCREASE TO 7-10 KTS FROM THE ENE AFTER 14Z FRI.
LOOKING BEYOND 18Z FRI... VFR CONDITIONS SHOULD DOMINATE THROUGH AT
LEAST SUNDAY... ALTHOUGH MVFR FOG IS POSSIBLE EARLY SAT MORNING AS
THE LIGHT ONSHORE LOW LEVEL FLOW PERSISTS. A PERIOD OF MVFR CIGS IS
POSSIBLE LATE SUN INTO SUN NIGHT AHEAD OF A COLD FRONT. VFR
CONDITIONS SHOULD THEN RETURN FOR MON/TUE WITH HIGH PRESSURE
BUILDING IN FROM THE NW. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...MWS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
121 AM EDT THU SEP 18 2014
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND DOWN INTO THE CAROLINAS FROM THE NORTH
PROVIDING FALL-LIKE WEATHER FOR THE REMAINDER OF THE WEEK. THE NEXT
COLD FRONT WILL MOVE THROUGH ON TUESDAY FOLLOWED BY COOL AND DRY
HIGH PRESSURE THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
ISOLATED CONVECTION HAS CONTINUED ACROSS ROBESON COUNTY AND ALSO
JUST OFF THE NEW HANOVER COUNTY BEACHES THIS EVENING. WITH SURFACE
TEMPERATURES NOW 70-74 DEGREES IN MOST LOCATIONS SURFACE-BASED
CAPE IS BELOW 1000 J/KG WITH 20-40 J/KG OF CONVECTIVE INHIBITION
TO DEAL WITH. HOWEVER LIFTING PARCELS FROM 925 MB GIVES ABOUT THE
SAME INSTABILITY WITH NO SIGNIFICANT CAPPING. THIS IS LIKELY THE
SOURCE REGION FOR THE ONGOING SHOWERS AND THUNDERSTORMS. ACTIVITY
APPEARS TO BE FOCUSED ALONG AN INVERTED TROUGH THAT IS THE LEADING
EDGE OF A MODEST NORTHEASTERLY SURGE OVER EASTERN NORTH CAROLINA.
GIVEN THE VERY MOIST AIRMASS UP THROUGH 850 MB THERE IS NO REASON
THIS INVERTED TROUGH/SURGE LINE CANNOT SERVE AS THE FOCUS FOR
ADDITIONAL SHOWERS OR THUNDERSTORMS ALL THE WAY THROUGH THE NIGHT
AS IT MOVES SOUTHWESTWARD THROUGH EASTERN SOUTH CAROLINA. IN
AGREEMENT WITH THE LATEST HRRR (NCEP PARALLEL VERSION) WILL
MAINTAIN 20-30 POPS ACROSS MOST OF EASTERN SOUTH CAROLINA THROUGH
THE NIGHT. THIS MAY HAVE SOME NEGATIVE IMPACT ON THE DEVELOPMENT
OF FOG AND LOW STRATUS LATE TONIGHT...BUT NO SIGNIFICANT CHANGES
WERE MADE TO THAT PORTION OF THE FORECAST. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
CHANGES TO THE FORECAST EARLY THIS EVENING CENTER ON OBSERVED RADAR
TRENDS. CONVECTION IS FINALLY DIMINISHING IN INTENSITY AND COVERAGE
ACROSS THE CAPE FEAR AREA...BUT A RENEWED CLUSTER OF STORMS IS
CROSSING THE SANTEE RIVER WITH ITS SIGHTS SET ON GEORGETOWN IN THE
NEXT HOUR. STORM MOTION IS BEING DRIVEN PRIMARILY BY BOUNDARIES AND
COLD POOL INTERACTIONS...ALTHOUGH A TREND NOTED WITH THE TALLER MORE
SIGNIFICANT THUNDERSTORMS HAS BEEN TO ACCELERATE EASTWARD DUE TO
STRONG WEST WINDS UP ABOVE 600 MB THAT THE SHALLOWER LESS
SIGNIFICANT CONVECTION ISN`T BEING AFFECTED BY. THE SPC MESOANALYSIS
PAGE SHOWS SURFACE-BASED CAPE IS AROUND 1500 J/KG WITH FAVORABLE
MID-LEVEL LAPSE RATES AROUND 6 DEG C/KM.
CONVECTIVE TRENDS THIS EVENING SHOULD BE TOWARD A SLOW DECREASE IN
ACTIVITY AS THE SURFACE COOLS. PLENTY OF DRY AIR ABOVE 700 MB HAS
BEEN HELPING PRODUCE CONVECTIVE OUTFLOW BOUNDARIES DUE TO
ENTRAINMENT INTO DOWNDRAFTS. THE LATEST FEW HRRR RUNS SHOW THERE MAY
BE A FEW LINGERING SHOWERS ACROSS NE SOUTH CAROLINA ROOTED IN A
LAYER OF UNSTABLE AIR AT 950-925 MB PERSISTING AFTER MIDNIGHT. I`LL
KEEP SOME 20 POPS GOING FROM MYRTLE BEACH AND MARION SOUTHWARD
BETWEEN 03-06Z TO ACCOUNT FOR THIS POTENTIAL.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO OTHER FORECAST ELEMENTS.
LOWS SHOULD STILL FALL INTO THE LOWER TO MID 60S FOR MOST AREAS AS
WEAK COOL ADVECTION DEVELOPS OVERNIGHT ON LIGHT NE WINDS BELOW 850
MB. LINGERING LOW-LEVEL MOISTURE WILL ALMOST CERTAINLY CREATE LOW
STRATUS AND FOG LATE TONIGHT...ESPECIALLY INLAND FROM THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE BUILDING DOWN INTO THE
CAROLINAS FROM THE GREAT LAKES ON THURS WILL SHIFT EAST PRODUCING
A VERY PRONOUNCED WEDGE PATTERN BY FRI AFTN. AT THE SAME TIME THE
MID TO UPPER TROUGH OVER THE EAST COAST WILL LIFT OFF TO THE
NORTHEAST. BEFORE THE TROUGH LIFTS OFF...A COUPLE OF MINOR
PERTURBATIONS RIDING AROUND THE BASE MAY ENHANCE CLOUDS AND LOW
END PCP ON THURS...BUT NOT COUNTING ON MUCH. AS TROUGH LIFTS OFF
THROUGH FRI...IT MAY PROVIDE ENOUGH OF A WEAKNESS TO ALLOW
DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST TO RETROGRADE
BACK TO THE W-NW THROUGH FRI NIGHT. OVERALL EXPECT DECENT
NORTHEAST FLOW AS GRADIENT BECOMES MORE PINCHED AS TROUGH OF LOW
PRESSURE SHIFTS NORTH TOWARD THE SOUTHEAST COAST THROUGH LATE FRI
INTO FRI NIGHT. THE NAM HAS THE LOW MOVING FARTHER WEST WITH A
GREATER ON SHORE FLOW OF MOISTURE THROUGH FRI AND A MUCH WETTER
FORECAST...WHILE THE GFS/ECMWF CONFINE THE GREATEST MOISTURE OFF
SHORE AND JUST ALONG THE COAST. FOR NOW WILL GO WITH BRUNT OF CLOUDS
AND POPS OFF SHORE AND JUST ALONG THE COAST IN NE FLOW THROUGH
FRI NIGHT.
NORTHEAST FLOW WILL HELP KEEP HIGH TEMPERATURES ALONG THE COAST A
LITTLE BELOW CLIMO THROUGH THE PERIOD. FARTHER INLAND HIGHS WILL BE
NEAR CLIMO WITH A LITTLE MORE SUN. LOW TEMPERATURES WILL END UP A
LITTLE ABOVE CLIMO DUE TO CLOUDS AND BOUNDARY LAYER MIXING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...POTENTIALLY UNSETTLED TO START THE
PERIOD...BUT EVEN BY D4 THERE IS CONSIDERABLE MODEL SPREAD. STALLED
BOUNDARY OFFSHORE WILL BE A FOCUS FOR LOW PRESSURE DEVELOPMENT...BUT
THE QUESTION REMAINS HOW CLOSE TO THE COAST THIS LOW WILL FORM. THE
NAM/CMC ARE IN ONE CAMP WITH DEEP EASTERLY FLOW AHEAD OF A LOW
PRESSURE MOVING RIGHT ALONG THE COAST...CAUSING WIDESPREAD AND
POSSIBLY HEAVY...RAINFALL. THE GFS/ECMWF ARE FURTHER OFFSHORE...WITH
NE FLOW THROUGH THE WEEKEND AS THE LOW PRESSURE STAYS WELL OFF THE
COAST. WPC FAVORING THE ECMWF AND ITS ENSEMBLES...WHICH HAVE
FLUCTUATED LITTLE FROM LAST WEEK...AND THUS WILL CONTINUE WITH THE
INHERITED FORECAST LEANING SIGNIFICANTLY ON THE ECMWF WITH SOME
BLENDING WITH THE WETTER SOLUTIONS. THIS SUGGESTS AT LEAST
WIDESPREAD CLOUD COVER SATURDAY AS THE LOW PRESSURE MAKES ITS
CLOSEST APPROACH...WITH SHOWERS MOST LIKELY ACROSS THE EASTERN
ZONES. IMPROVEMENT WILL OCCUR ON SUNDAY AS THE LOW PRESSURE PULLS
OFF TO THE NORTHEAST...AND TEMPS WILL BE AROUND SEASONABLE THROUGH
THE WKND...ALTHOUGH SUNDAY WILL LIKELY BE A BIT WARMER.
A BRIEF PERIOD OF RETURN FLOW DEVELOPS AHEAD OF A STRONG COLD FRONT
WHICH IS SLATED TO CROSS TUESDAY AFTN. THIS BRINGS A DAY OR TWO OF
WARMER TEMPERATURES...BEFORE CANADIAN HIGH PRESSURE ENVELOPS THE
REGION FOR MID-WEEK. CONVECTION LOOKS LIKELY ON TUESDAY WITH THE
COLD FRONT...AND WILL BUMP POP TO CHC FOR TUESDAY AS SURFACE
CONVERGENCE...PVA...AND SOME JET-LEVEL DIFFLUENCE COMBINE IN A RICH
THETA-E AIR MASS.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...EXPECT IFR/LIFR BR/STRATUS TO DEVELOP AT KFLO AND KLBT
AFTER 09Z WITH LIGHT/CALM WINDS AND DECREASING CLOUD COVER. ALONG
THE COAST...SLIGHTLY STRONGER NORTHEAST FLOW WILL LIKELY KEEP VSBYS
FROM DROPPING BELOW MVFR LEVELS BEFORE 12Z. THERE IS A CHANCE THAT
SOME TEMPO IFR CIGS COULD DEVELOP AT KCRE/KMYR BETWEEN 10-12Z...BUT
CONFIDENCE IS LOW SO WILL KEEP IFR STRATUS SCT ATTM. MVFR CIGS SEEM
MORE LIKELY FOR KILM/KCRE/KMYR JUST AFTER DAYBREAK. PATCHES OF MVFR
CIGS MAY LINGER THROUGH THE LATE MORNING...BUT EXPECT VFR AT ALL TAF
SITES BY MIDDAY. THEN VFR SHOULD PREVAIL THROUGH THE REST OF THE
PERIOD. NORTHEAST WINDS AOB 10 KT WILL BECOME MORE EASTERLY AFTER
18Z. DO NOT ANTICIPATE MUCH...IF ANY...PCPN DURING THE DAY GIVEN THE
DRY AIR ALOFT SEEN IN THE FCST SOUNDINGS.
EXTENDED OUTLOOK...GUSTY NORTHEAST WINDS EXPECTED FRI/SAT AS COOL
HIGH PRESSURE EXTENDS SOUTHWARD INTO THE CAROLINAS. EARLY MORNING
MVFR/IFR STRATUS POSSIBLE SAT/SUN MORNING. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
WINDS ACROSS THE COASTAL WATERS NORTH OF CAPE FEAR ARE A LITTLE
STRONGER THAN ANTICIPATED EARLIER. THIS IS LIKELY DUE TO A
TIGHTENING PRESSURE GRADIENT BEHIND A MODEST SURGE LINE/INVERTED
TROUGH THAT IS DROPPING SLOWLY SOUTHWESTWARD ALONG THE COAST. WIND
GUSTS UP TO 21 KNOTS HAVE BEEN MEASURED AT CAPE LOOKOUT AND
WRIGHTSVILLE BEACH WITHIN THE PAST HOUR. NO MODEL HAS WINDS THIS
STRONG CURRENTLY...BUT I HAVE BUMPED WIND SPEED FORECASTS UP TO A
SOLID 15 KNOTS NORTH OF CAPE FEAR...AND 10-15 KNOTS SOUTH OF CAPE
FEAR TO NEAR MYRTLE BEACH. SEAS ARE UP TO A SOLID 4 FEET NORTH OF
CAPE FEAR IN A COMBINATION OF SWELL AND WIND WAVES. PREVIOUS
DISCUSSION FROM 730 PM FOLLOWS...
WEAK LOW PRESSURE WELL OFF THE SC COAST WILL MAINTAIN A LIGHT NE
WIND OVERNIGHT. HIGH PRESSURE NORTH OF THE GREAT LAKES WILL BEGIN TO
RIDGE SOUTHWARD LATE TONIGHT. A SLIGHT NE SURGE TONIGHT WILL
INCREASE WIND SPEEDS UP TO 10 TO 15 KT. EASTERLY SWELL FROM DISTANT
HURRICANE EDOUARD WILL ALLOW SEAS TO BE CONSIDERABLY HIGHER THAN THE
WIND SPEEDS WOULD OTHERWISE INDICATE... 3 TO 4 FT OUTSIDE OF
SHOALING/NEARSHORE INFLUENCES...WITH DOMINANT PERIODS OF 12 TO 13
SECONDS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE RIDGING DOWN FROM THE NORTH
WILL PRODUCE LIGHT NORTHEAST FLOW ON THU AROUND 10 KTS OR LESS. WINDS
WILL WILL INCREASE SIGNIFICANTLY THROUGH FRI AS DISTINCT HIGH
PRESSURE WEDGE SETS UP AND LOW PRESSURE DEVELOPS OFF THE SOUTHEAST
COAST. NE WINDS WILL INCREASE UP TO 20 KT WITH HIGHER GUSTS THROUGH
FRI INTO FRI NIGHT AND MAY BECOME MORE EASTERLY DEPENDING ON
POSITION AND STRENGTH OF DEVELOPING LOW OFF THE SOUTHEAST COAST.
SEAS 2 TO 4 FT ON THURS WILL DIMINISH SLIGHTLY THROUGH THE DAY AS
LONG PERIOD SWELLS DECREASE. AS NE WINDS INCREASE THROUGH FRI...SEAS
MAY REACH SCA THRESHOLDS INTO FRI EVE...ESPECIALLY NORTH OF CAPE
FEAR...BUILDING TO 4 TO 5 FT WITH POTENTIAL FOR 6 FT. MAINLY IN
OUTER WATERS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...CONCERN THROUGH THE EXTENDED INVOLVES A LOW
PRESSURE SYSTEM PROGGED TO DEVELOP ALONG A STALLED COLD FRONT OFF
THE COAST. STILL SIGNIFICANT UNCERTAINTY INTO THE STRENGTH AND EXACT
PLACEMENT OF THIS FEATURE...BUT AT LEAST SOME IMPACTS ARE EXPECTED
LOCALLY. THIS LOW PRESSURE WILL MAKES ITS CLOSEST APPROACH TO THE
WATERS ON SATURDAY...PRODUCING ENHANCED NE WINDS OF 15-20
KTS...POSSIBLY HIGHER IF THE LOW IS CLOSER/STRONGER THAN CURRENTLY
FORECAST. WINDS THEN BECOME VARIABLE ON SUNDAY AS A WEAK RIDGE OF
HIGH PRESSURE BUILDS TOWARDS THE AREA...BEFORE TURNING TO THE SW
WIND SW ON MONDAY...WITH SPEEDS RISING BACK TO 10-15 KTS. WAVES WILL
BE PRIMARILY NE-WIND-WAVE DRIVEN ON SATURDAY WITH HEIGHTS 4-5
FT...BUT AGAIN...IF THE SYSTEM IS STRONGER OR CLOSER AN SCA MAY BE
NEEDED. THEREAFTER...WAVE HEIGHTS FALL TO 2-4 FT ON SUNDAY...AND
THEN 1-3 ON MONDAY WITH A SW WIND WAVE AND WEAK SE SWELL FORMING IN
THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...REK/RJD
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...BJR
MARINE...REK/RJD/JDW/RGZ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
952 PM CDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 952 PM CDT FRI SEP 19 2014
CONVECTION HAS ALL BUT ENDED ACROSS WESTERN AND CENTRAL NORTH
DAKOTA WITH THE SETTING SUN. STILL AN ISOLATED SHOWER ALONG THE
MISSOURI RIVER BORDERING MONTANA...BUT THIS ACTIVITY HAS BEEN
DECREASING AND EXPECT THIS TO CONTINUE. THUS HAVE REMOVED POPS FOR
THIS EVENING. MODELS SUGGEST NEXT WAVE WILL BE MOVING INTO
SOUTHEAST SASKATCHEWAN LATE TONIGHT AND HAVE UTILIZED THE 01 UTC
RAP AS A GUIDE FOR TIMING OF THE PRECIPITATION WITH THIS WAVE.
BROUGHT SHOWERS INTO THE FAR NORTHWEST AROUND 09-10 UTC WITH
SHOWERS AND ISOLATED THUNDERSTORMS GENERALLY ALONG AND NORTH OF A
LINE FROM WILLISTON TO GARRISON TO JAMESTOWN ON SATURDAY...WITH
PRECIPITATION ENDING IN THE SOUTHERN JAMES RIVER VALLEY BY MID TO
LATE AFTERNOON.
UPDATE ISSUED AT 642 PM CDT FRI SEP 19 2014
ISOLATED THUNDERSTORMS CONTINUE TO TRACK SOUTHEAST ACROSS
BOTTINEAU AND MCHENRY COUNTIES IN NORTH CENTRAL NORTH
DAKOTA. STRONGER CELLS HAVE REMAINED OVER NORTHEAST NORTH DAKOTA
NEAR THE SURFACE LOW PRESSURE SYSTEM. GUSTY NORTHWEST WINDS BEHIND
THE LOW SHOULD DIMINISH EARLY THIS EVENING ACROSS THE WEST AND
CENTRAL. UPDATED SKY COVER AND POP GRIDS BASED ON LATEST RADAR AND
SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT UPDATES NEEDED.
&&
.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 952 PM CDT FRI SEP 19 2014
VFR CONDITIONS EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE 00Z TAF PERIOD. CONVECTION REMAINED EAST OF MINOT AND
NORTH OF JAMESTOWN. SCATTERED VFR CLOUDINESS THROUGH THE EVENING
WITH VFR CEILINGS POSSIBLE AGAIN SATURDAY MORNING THROUGH EARLY
AFTERNOON...BASES AROUND 7-10KFT TRACKING MAINLY FROM KMOT TO KJMS
AS ANOTHER QUICK MOVING SYSTEM MOVES THROUGH. DID MENTION A VCSH
AT KMOT AND KJMS SATURDAY MORNING. NORTHWEST FLOW WILL INCREASE
AGAIN SATURDAY AFTERNOON WITH GUSTS TO AROUND 30 KTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...JV
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 PM CDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 642 PM CDT FRI SEP 19 2014
ISOLATED THUNDERSTORMS CONTINUE TO TRACK SOUTHEAST ACROSS
BOTTINEAU AND MCHENRY COUNTIES IN NORTH CENTRAL NORTH
DAKOTA. STRONGER CELLS HAVE REMAINED OVER NORTHEAST NORTH DAKOTA
NEAR THE SURFACE LOW PRESSURE SYSTEM. GUSTY NORTHWEST WINDS BEHIND
THE LOW SHOULD DIMINISH EARLY THIS EVENING ACROSS THE WEST AND
CENTRAL. UPDATED SKY COVER AND POP GRIDS BASED ON LATEST RADAR AND
SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT UPDATES NEEDED.
&&
.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 642 PM CDT FRI SEP 19 2014
VFR CONDITIONS EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE 00Z TAF PERIOD. CURRENT CONVECTION HAS REMAINED EAST
OF MINOT AND AT THIS TIME IS EXPECTED TO REMAIN NORTH OF
JAMESTOWN. CONVECTION NORTHWEST OF WILLISTON HAS ALSO DIMINISHED
DURING THE PAST HOUR...THUS NO MENTION OF THUNDER IN THE TAFS THIS
EVENING. SCATTERED VFR CLOUDINESS THROUGH THE EVENING WITH VFR
CEILINGS POSSIBLE AGAIN SATURDAY MORNING THROUGH EARLY
AFTERNOON...BASES AROUND 7-10KFT TRACKING MAINLY FROM KMOT TO KJMS
AS ANOTHER QUICK MOVING SYSTEM MOVES THROUGH. DID MENTION A VCSH
AT KMOT AND KJMS SATURDAY MORNING. NORTHWEST FLOW WILL INCREASE
AGAIN SATURDAY AFTERNOON WITH GUSTS TO AROUND 30 KTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...JV
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
326 PM CDT THU SEP 18 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 326 PM CDT THU SEP 18 2014
CONVECTIVE FORECAST CONTINUES TO BE COMPLICATED BY A RELATIVELY
STRONG LOW LEVEL CAPPING INVERSION ACROSS CENTRAL AND EASTERN
NORTH DAKOTA BUT WITH MID AND HIGH CAPE ABOVE AS MOST FLOW
OVERRIDES. WARM FRONT CURRENTLY EXTENDS FROM LOW PRESSURE IN
SOUTH CENTRAL SASKATCHEWAN SOUTHEAST THROUGH WESTERN NORTH DAKOTA.
WARM ADVECTION OVER THE WARM FRONT CURRENTLY GENERATING SOME
ELEVATED CONVECTION ACROSS NORTH CENTRAL NORTH DAKOTA AS CURRENT
NAM MODEL FAIRLY WELL PREDICTS. LATEST HRRR DOES NOT HANDLE THIS
WELL. CURRENT THINKING HAS THE MAJORITY OF CONVECTION WITH THE
COLD FRONT LATER TONIGHT. POPS FOR TONIGHT ARE STILL A BIT SPOTTY
OWING TO THE CAP...MOSTLY 20 TO 30 POPS. BY FRIDAY NORTHWEST FLOW
BEHIND THE COLD FRONT WILL SUPPRESS THUNDERSTORMS SOUTH AND
FOCUSED ON THE NORTH HALF FRIDAY AFTERNOON. LOWS TONIGHT 55 TO 65
AND HIGHS FRIDAY 78 TO 86.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 326 PM CDT THU SEP 18 2014
FRIDAY NIGHT THROUGH SATURDAY THE FORECAST AREA WILL BE UNDER THE
INFLUENCE OF NORTHWEST FLOW ALOFT WITH WEAK SHORT WAVES EMBEDDED IN
THE FLOW. THUS WILL KEEP THE SMALL CHANCE MENTION OF THUNDERSTORMS
MAINLY OVER NORTHERN COUNTIES.
THEN THE UPPER LEVEL WESTERN RIDGE PUSHES EASTWARD...ALONG WITH
SURFACE HIGH PRESSURE...BRINGING DRY CONDITIONS TO WESTERN AND
CENTRAL NORTH DAKOTA THROUGH MONDAY.
ALONG WITH THE WESTERN RIDGE...AN UPPER LEVEL LOW OVER CALIFORNIA
SATURDAY WILL MEANDER SLOWLY BENEATH THE RIDGE CREATING A REX BLOCK
OVER THE ROCKIES. BY EARLY NEXT WEEK THE WESTERN RIDGE BEGINS TO
PROGRESS EASTWARD AND THE MEANDERING UPPER LOW IS FORECAST TO MOVE
INTO THE PLAINS. MODELS ARE COMING INTO BETTER AGREEMENT AND LIFTING
THE UPPER LOW NORTHEASTWARD - APPROACHING NORTH DAKOTA ON TUESDAY.
THIS SLOW-MOVING LOW WILL BRING SOME CHANCE OF SHOWERS/THUNDER TO
THE REGION TUESDAY THROUGH THURSDAY...BUT CONFIDENCE IS NOT HIGH
REGARDING ITS IMPLICATIONS FOR PLACEMENT/TIMING OF PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 326 PM CDT THU SEP 18 2014
LOW PRESSURE IN SOUTH CENTRAL SASKATCHEWAN WITH AN ASSOCIATED WARM
FRONT WILL MOVE EAST TONIGHT. THIS WILL BE FOLLOWED BY A COLD FRONT
LATE TONIGHT AND FRIDAY. SCATTERED TO WIDELY SCATTERED THUNDERSTORMS
WILL BE ASSOCIATED WITH THE WARM FRONT ACROSS CENTRAL NORTH DAKOTA
THIS EVENING. THE COLD FRONT WILL BE THE FOCUS FOR THUNDERSTORMS
ACROSS WEST AND CENTRAL TONIGHT...AND ACROSS NORTHERN NORTH DAKOTA
FRIDAY. USED VCTS TO DESCRIBE THE THUNDERSTORM THREAT EARLY ON BUT
OVERALL TO UNCERTAIN TO INCLUDE TSRA IN TAFS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
LONG TERM...JV
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1255 PM CDT THU SEP 18 2014
.UPDATE...
ISSUED AT 1249 PM CDT THU SEP 18 2014
AFTERNOON FORECAST ON TRACK AS JUST A FINGER OF STRATUS LEFT ON
VISIBLE SATELLITE IMAGERY IMPACTING THE ND SIDE OF THE RRV. TEMPS
WARMING RAPIDLY WITH SUN...UP 10 DEGREES AT CROOKSTON IN THE PAST
90 MIN. STILL SEE NO REASON FOR ADJUSTING MAX TEMPS SO WILL LEAVE
THEM IN THE 70S VALLEY AND WEST WITH UPPER 60S IN THE MN PINES.
UPDATE ISSUED AT 936 AM CDT THU SEP 18 2014
CHALLENGES FOR THIS MORNINGS UPDATE INCLUDES LOW STRATUS AND
DISSIPATING FOG. STRATUS DECK ALONG AND EAST OF THE RRV WILL
ERODE AS PRESSURE GRADIENT INCREASES BETWEEN DEPARTING GREAT
LAKES SFC HIGH AND DEVELOPING TROUGH OF LOW PRESSURE IN THE HIGH
PLAINS. THIS MIXING WILL QUICKLY ERODE THE STRATUS IN THE NEXT
COUPLE OF HOURS. THE RAP AND HRRR INDICATE THIS IN THEIR LATEST
SOLNS. ADJUSTED THE SKY GRIDS AND TEMP CURVE THROUGH EARLY
AFTERNOON AND KEPT THE INHERITED MAX TEMPS THE SAME.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
THE MAIN CHALLENGE WILL BE CONVECTIVE CHANCES LATER TODAY THROUGH
SATURDAY. MODELS REMAIN IN VERY GOOD OVERALL AGREEMENT...WITH A
FEW MINOR DIFFERENCES.
FOR TODAY...THERE WILL BE A BAND OF CLOUDS AT LEAST THIS MORNING
AFFECTING AREAS ALONG AND EAST OF THE VALLEY. THERE IS ALSO SOME
PATCHY FOG WITH THIS STRATUS...AND WILL ADD SOME FOR EARLY
MORNING. THIS STRATUS COULD HOLD TEMPS DOWN ONCE AGAIN IF THEY DO NOT
ERODE UNTIL MID/LATE AFTERNOON...SO TEMP FORECAST WILL BE TRICKY
FOR SOME AREAS WHERE CLOUDS HOLD. IT SHOULD REMAIN DRY THROUGH 00Z
FRI...WITH SOUTHEAST WINDS INCREASING THIS AFTERNOON.
FOR TONIGHT...THE CHANCES FOR SHOWERS AND STORMS SHOULD DEVELOP
FROM WEST TO EAST THROUGH THE NIGHT. IT COULD BE WINDY FOR MUCH OF
THE NIGHT WITH GOOD MIXING AT LEAST THIS EVENING...AND 30-40KT TO
MIX. A DEVELOPING INVERSION SHOULD KEEP STRONGER WINDS FROM MIXING
DOWN THOUGH. A STRONG CAP WILL BE IN PLACE MUCH OF THE NIGHT...BUT
THE CAP NEAR 850MB SHOULD ERODE LATE WITH THE BEST FORCING AND MID
LEVEL MOISTURE ADVECTION IN THE NORTH.
ON FRIDAY...THERE COULD BE A FEW BANDS OF SHOWERS AND STORMS...ONE
IN THE MORNING IN THE EAST...AND ANOTHER LATER IN THE AFTERNOON IN
THE WEST. GIVEN THESE TOUGH TO TIME WAVES...WE WILL CONTINUE WITH
MAINLY LOW END CHANCE POPS FOR SHOWERS AND STORMS. IT SHOULD BE
WARM WITH WESTERLY SFC WINDS AND AT LEAST SOME SUNSHINE...WITH
AROUND 80 IN THE WEST AND LOW 70S EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
FOR FRI NIGHT...EXPECT CONTINUED CHANCES FOR SOME CONVECTION...AS
AS A SFC BOUNDARY MOVES THROUGH THE AREA. THE BEST CHANCE FOR
MEASURABLE RAIN WILL OCCUR IN THE NORTHERN AREAS CLOSER TO SFC LOW TRACK.
ON SATURDAY...A STRONG SPEED MAX WILL ENHANCE LARGE SCALE
DIVERGENCE ALOFT. THIS COUPLED WITH PWATS STILL NEAR 1 INCH IN THE
NORTH...AND SOME LINGERING INSTABILITY SHOULD MEAN MAINLY SHOWER
CHANCES AND PERHAPS A RUMBLE OF THUNDER. THE BEST CHANCE FOR
PRECIP COULD OCCUR LATE IN THE MORNING/EARLY AFTERNOON AS
SHORTWAVE MOVES THROUGH. COOL ADVECTION WILL MOVE IN SAT AFTERNOON
WITH NW WINDS INCREASING TO AT LEAST 20KT IN THE NW...ALONG WITH
ADIABATIC SOUNDINGS UP TO AROUND 700MB WITH 35KT TO MIX. TEMPS
WILL BE COOL TO AROUND NORMAL...WITH MORE CLOUDS AND CAA BY
AFTERNOON.
FOR SAT NIGHT...IT SHOULD BE MAINLY DRY WITH PERHAPS A LINGERING
SHOWER MAINLY IN THE NORTHEAST.
LONG WAVE RIDGE AXIS REMAINS OVER WESTERN CANADA THROUGH MUCH OF THE
PERIOD. BY DAY 7 ZONAL FLOW IS ACROSS CANADA. THE GFS IS FASTER THAN
THE ECMWF. WILL PREFER THE SLOWER ECMWF.
UPPER LOW OFF THE WEST COAST IS FORECAST TO MOVE INTO THE PLAINS BY
WED. WILL ADD POPS FOR WED.
TEMPS WERE DECREASED BY A DEGREE FOR SUN AND INCREASED A DEGREE FOR
MON...TUE AND WED COMPARED TO YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1249 PM CDT THU SEP 18 2014
IFR CLD COVER RAPIDLY ERODING WITH VFR CONDITIONS ARRIVING AT VALLEY
AIRFIELDS. GRADIENT WIND FROM SOUTH STARTING TO INCREASE
NOW...EXPECT 15 TO 20 KTS G25 EVERYWHERE BY MID AFTERNOON. RW/TRW TO
APPROACH OVERNIGHT INTO THUR...SUFFICIENTLY LOW POP WARRANTS
OMISSION FROM TAFS AT THIS TIME.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JK
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...WJB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
947 AM CDT THU SEP 18 2014
.UPDATE...
ISSUED AT 936 AM CDT THU SEP 18 2014
CHALLENGES FOR THIS MORNINGS UPDATE INCLUDES LOW STRATUS AND
DISSIPATING FOG. STRATUS DECK ALONG AND EAST OF THE RRV WILL
ERODE AS PRESSURE GRADIENT INCREASES BETWEEN DEPARTING GREAT
LAKES SFC HIGH AND DEVELOPING TROUGH OF LOW PRESSURE IN THE HIGH
PLAINS. THIS MIXING WILL QUICKLY ERODE THE STRATUS IN THE NEXT
COUPLE OF HOURS. THE RAP AND HRRR INDICATE THIS IN THEIR LATEST
SOLNS. ADJUSTED THE SKY GRIDS AND TEMP CURVE THROUGH EARLY
AFTERNOON AND KEPT THE INHERITED MAX TEMPS THE SAME.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
THE MAIN CHALLENGE WILL BE CONVECTIVE CHANCES LATER TODAY THROUGH
SATURDAY. MODELS REMAIN IN VERY GOOD OVERALL AGREEMENT...WITH A
FEW MINOR DIFFERENCES.
FOR TODAY...THERE WILL BE A BAND OF CLOUDS AT LEAST THIS MORNING
AFFECTING AREAS ALONG AND EAST OF THE VALLEY. THERE IS ALSO SOME
PATCHY FOG WITH THIS STRATUS...AND WILL ADD SOME FOR EARLY
MORNING. THIS STRATUS COULD HOLD TEMPS DOWN ONCE AGAIN IF THEY DO NOT
ERODE UNTIL MID/LATE AFTERNOON...SO TEMP FORECAST WILL BE TRICKY
FOR SOME AREAS WHERE CLOUDS HOLD. IT SHOULD REMAIN DRY THROUGH 00Z
FRI...WITH SOUTHEAST WINDS INCREASING THIS AFTERNOON.
FOR TONIGHT...THE CHANCES FOR SHOWERS AND STORMS SHOULD DEVELOP
FROM WEST TO EAST THROUGH THE NIGHT. IT COULD BE WINDY FOR MUCH OF
THE NIGHT WITH GOOD MIXING AT LEAST THIS EVENING...AND 30-40KT TO
MIX. A DEVELOPING INVERSION SHOULD KEEP STRONGER WINDS FROM MIXING
DOWN THOUGH. A STRONG CAP WILL BE IN PLACE MUCH OF THE NIGHT...BUT
THE CAP NEAR 850MB SHOULD ERODE LATE WITH THE BEST FORCING AND MID
LEVEL MOISTURE ADVECTION IN THE NORTH.
ON FRIDAY...THERE COULD BE A FEW BANDS OF SHOWERS AND STORMS...ONE
IN THE MORNING IN THE EAST...AND ANOTHER LATER IN THE AFTERNOON IN
THE WEST. GIVEN THESE TOUGH TO TIME WAVES...WE WILL CONTINUE WITH
MAINLY LOW END CHANCE POPS FOR SHOWERS AND STORMS. IT SHOULD BE
WARM WITH WESTERLY SFC WINDS AND AT LEAST SOME SUNSHINE...WITH
AROUND 80 IN THE WEST AND LOW 70S EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT THU SEP 18 2014
FOR FRI NIGHT...EXPECT CONTINUED CHANCES FOR SOME CONVECTION...AS
AS A SFC BOUNDARY MOVES THROUGH THE AREA. THE BEST CHANCE FOR
MEASURABLE RAIN WILL OCCUR IN THE NORTHERN AREAS CLOSER TO SFC LOW TRACK.
ON SATURDAY...A STRONG SPEED MAX WILL ENHANCE LARGE SCALE
DIVERGENCE ALOFT. THIS COUPLED WITH PWATS STILL NEAR 1 INCH IN THE
NORTH...AND SOME LINGERING INSTABILITY SHOULD MEAN MAINLY SHOWER
CHANCES AND PERHAPS A RUMBLE OF THUNDER. THE BEST CHANCE FOR
PRECIP COULD OCCUR LATE IN THE MORNING/EARLY AFTERNOON AS
SHORTWAVE MOVES THROUGH. COOL ADVECTION WILL MOVE IN SAT AFTERNOON
WITH NW WINDS INCREASING TO AT LEAST 20KT IN THE NW...ALONG WITH
ADIABATIC SOUNDINGS UP TO AROUND 700MB WITH 35KT TO MIX. TEMPS
WILL BE COOL TO AROUND NORMAL...WITH MORE CLOUDS AND CAA BY
AFTERNOON.
FOR SAT NIGHT...IT SHOULD BE MAINLY DRY WITH PERHAPS A LINGERING
SHOWER MAINLY IN THE NORTHEAST.
LONG WAVE RIDGE AXIS REMAINS OVER WESTERN CANADA THROUGH MUCH OF THE
PERIOD. BY DAY 7 ZONAL FLOW IS ACROSS CANADA. THE GFS IS FASTER THAN
THE ECMWF. WILL PREFER THE SLOWER ECMWF.
UPPER LOW OFF THE WEST COAST IS FORECAST TO MOVE INTO THE PLAINS BY
WED. WILL ADD POPS FOR WED.
TEMPS WERE DECREASED BY A DEGREE FOR SUN AND INCREASED A DEGREE FOR
MON...TUE AND WED COMPARED TO YESTERDAYS RUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 615 AM CDT THU SEP 18 2014
THE BAND OF IFR/LIFR STRATUS AND FOG CONTINUES TO ADVECT WEST INTO
THE VALLEY. THIS WILL BE CHALLENGING TO WHEN IT DISSIPATES...AND
IF KDVL IS AFFECTED. CURRENT THINKING IS IT WILL SLOW ITS WESTWARD
PROGRESSION WITHIN A FEW HOURS THEN DISSIPATE BY 18Z. THIS WILL
NEED TO BE MONITORED CLOSELY THOUGH. SOUTHEAST WINDS WILL INCREASE
THIS AFTERNOON AND COULD GUST TO AROUND 25KT LATE THIS AFTERNOON
INTO THIS EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JK
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...DK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
700 PM EDT THU SEP 18 2014
.SYNOPSIS...
HIGH PRESSURE THROUGH SATURDAY. COLD FRONT SUNDAY. HIGH PRESSURE
NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
LOWER DEW POINTS HAVE FILTERED INTO SOUTHEAST OHIO AND NORTHERN WEST
VIRGINIA LATE THURSDAY AFTERNOON. WILL LOWER MINIMUM TEMPERATURE
THERE A FEW DEGREES.
AT 2245Z...VAD WINDS AT 925 MB STILL FM THE NNE. RAP MODEL QUICKLY
VEERS THE 925 MB FLOW TO EAST BY 06Z. THUS CLOUDS SHOULD INCREASE
ALONG THE EASTERN SLOPES OVERNIGHT. WILL FAVOR CLOUDS OVER FOG FOR
THE UPPER GREENBRIER VALLEY IN POCAHONTAS COUNTY.
DEW POINTS THE HIGHEST CRW ON SOUTH NEAR SUNSET. THINKING THAT AREA
HAS THE BEST CHANCE FOR DIURNAL FOG...FORMING FIRST OVER THE
HEADWATERS OF THE TUG FORK AND GUYANDOTTE RIVER VALLEYS.
NO CHANGES TO POPS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A HIGH PRESSURE SYSTEM CONTINUES OVER THE AREA FOR FRIDAY NIGHT AND
SATURDAY. NAM IS SHOWING SOME MOISTURE IN THE MOUNTAINS SATURDAY
AFTERNOON...POSSIBLY ALLOWING FOR A COUPLE OF SHOWERS.
A COLD FRONT THEN MOVES THROUGH ON SUNDAY. THE ECMWF AND GFS ARE THE
FASTEST WITH THIS SYSTEM...WITH THE NAM THE SLOWEST...AND THE SREF
AND CANADIAN IN BETWEEN. UPPER AIR SUPPORT WOULD LEND TOWARD A
SLOWER SOLUTION...BUT WITHOUT A LOT OF MODEL SUPPORT...WILL STAY
TOWARD THE MIDDLE GROUND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
USED WPC THINKING WITH SOME MINOR TWEAKS. COLD FRONT WILL PUSH
SOUTHEAST OF THE MOUNTAINS SUNDAY NIGHT WITH HIGH PRESSURE TAKING
CONTROL BY MONDAY AFTERNOON. THE HIGH SHOULD BE IN CONTROL THROUGH
THE REMAINDER OF THE PERIOD...RESULTING IN DRY AND SEASONABLY COOL
TEMPERATURES.
WPC TEMPS LOOKED GOOD AND WERE GENERALLY USED.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AT 2245Z...VAD WINDS AT 925 MB LEVEL STILL FM THE NNE. RAP MODEL
QUICKLY VEERS THE 925 MB FLOW TO EAST BY 06Z. THUS CLOUDS SHOULD
INCREASE ALONG THE EASTERN SLOPES IN THE 06Z TO 12Z FRIDAY TIME
FRAME. TIMING THE LOWER CEILINGS INTO BKW TRICKY...BUT HELD OFF
UNTIL AFTER 06Z. WILL TRY TO KEEP CEILINGS MOSTLY 1 TO 2 THSD FT
AND MVFR. SOME IFR CEILINGS POSSIBLE THOUGH OVER THE HIGHER RIDGES.
WILL FAVOR CLOUDS OVER FOG FOR THE UPPER GREENBRIER VALLEY IN
POCAHONTAS COUNTY. BUT FURTHER WEST...FAVORED FOG OVER CLOUDS FOR
ELKINS VCNTY.
DEW POINTS THE HIGHEST CRW ON SOUTH NEAR SUNSET. THINKING THAT AREA
HAS THE BEST CHANCE FOR IFR/LIFR DIURNAL FOG...FORMING FIRST OVER
THE HEADWATERS OF THE TUG FORK AND GUYANDOTTE RIVER
VALLEYS...FORECASTING IFR IN FOG REACHING CRW 06Z TO 08Z.
IN THE DRIER AIR FURTHER WEST AND NORTHWEST...SOME RIVER VALLEY FOG
OVER THE OHIO RIVER MAY FORM FOR 09Z TO 12Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING LOWERING CEILING INTO SRN WV MOUNTAINS
WITH THE DEVELOPING EASTERLY UPSLOPE FLOW AROUND BKW MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H M M L L
HTS CONSISTENCY H H H H H H H H H H M M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H M L L L M
PKB CONSISTENCY H H H H H H H H H M L L
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 00Z SATURDAY...
BRIEF IFR CONDITIONS POSSIBLE SUNDAY IN SHOWERS/STORMS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...50/26
NEAR TERM...KTB
SHORT TERM...RPY
LONG TERM...JSH
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS NORMAN OK
1200 AM CDT THU SEP 18 2014
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVERNIGHT. LIGHT SOUTH WINDS WILL
BECOME VARIABLE AT KLAW AND KSPS FROM 08Z THROUGH THE MORNING
HOURS. A WEAK FRONTAL BOUNDARY MAY RESULT IN EASTERLY WINDS FOR A
FEW HOURS DURING THE MORNING AT KPNC. WINDS WILL THEN INCREASE AND
SHIFT BACK TO A MORE SOUTHERLY DIRECTION FOR THE REMAINDER OF THE
DAY. SPOTTY SHRA/TSRA MAY DEVELOP FROM I-40 SOUTHWARD...BUT
CONFIDENCE IN IMPACTS TO ANY ONE TERMINAL REMAINS TOO LOW TO
INCLUDE IN TAFS.
&&
.PREV DISCUSSION... /ISSUED 936 PM CDT WED SEP 17 2014/
DISCUSSION...
WILL CONTINUE WITH LOW POPS MAINLY SOUTH OVERNIGHT WITH WEAK
IMPULSE MOVING OUT OF W TX. LATER HRRR RUNS HAVE BACKED OFF ON
ACTIVITY MOVING FROM KS INTO NRN OK OVERNIGHT...BUT WITH
SHOWERS/TSTMS STILL LINGERING IN ERN OK AND SFC BOUNDARY IN THE
AREA WILL ALSO LEAVE LOW POPS MAINLY E OF I-35.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 90 69 88 / 10 30 10 10
HOBART OK 71 91 69 88 / 10 30 10 20
WICHITA FALLS TX 72 91 70 89 / 20 30 20 20
GAGE OK 64 90 66 87 / 0 10 10 20
PONCA CITY OK 70 89 69 89 / 10 20 10 10
DURANT OK 72 89 69 88 / 20 30 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
02/84
AREA FORECAST DISCUSSION
NWS PENDLETON OR
1028 AM PDT THU SEP 18 2014
UPDATED AVIATION DISCUSSION
.UPDATE...THE CURRENT FORECAST REMAINS ON TRACK WITH JUST A FEW
MINOR ADJUSTMENTS TO THE TODAY AND THIS EVENING PERIOD. HAVE MADE
SOME MINOR ADJUSTMENTS TO THE HIGHS TODAY...MAINLY ACROSS THE
WESTERN PORTION OF THE CWA.
EXPECT WINDY CONDITIONS ALONG THE KITTITAS VALLEY AND THE COLUMBIA
RIVER GORGE TODAY...WITH THE BASIN AND FOOTHILL AREAS BEING BREEZY.
EXPECT 20 MPH GUSTING TO 30 MPH FOR THE GORGE AND THE KITTIAS
VALLEY...WITH 15 MPH GUSTING 25 MPH ELSEWHERE ACROSS THE BASIN.
WINDS SHOULD BEGIN TO PICK UP AFTER NOON TODAY...AND ARE EXPECTED TO
BE STRONGEST AROUND 5 PM DIMINISHING AFTER MIDNIGHT.
HAVE ALSO PULLED BACK ON POPS TO GO MOSTLY SLIGHT CHANCE EAST OF THE
CASCADE CREST. THE SPLIT FLOW WILL CUT OFF MOST OF THE MOISTURE
FROM THE TROUGH THAT WILL PROGRESS SOUTH ALONG THE CALIFORNIA COAST
TODAY INTO TONIGHT. SLIGHT CHANCE UPSLOPE SHOWERS CAN BE EXPECTED
ACROSS THE NORTHEAST MOUNTAINS TODAY AND THIS EVENING. HAVE
MENTIONED SLIGHT CHANCE THUNDER ACROSS THE NORTHEAST MOUNTAINS
THROUGH 5 PM...AS IT STILL CAN`T BE RULED OUT. BUT ONCE THE WEST
NORTHWEST FLOW SETS IN THIS EVENING...INSTABILITY WILL BE VERY
LIMITED. SO HAVE PULLED BACK ON THE THUNDER POTENTIAL TO JUST THE
EAGLE CAPS...SOUTHERN GRANT...CROOK...AND DESCHUTES COUNTY FROM 5 TO
8 PM THIS EVENING. WEBER
.AVIATION...18Z TAFS...VFR CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NEXT 24 HOURS. THERE MAY BE SOME LIGHT SHOWERS AROUND
THE REGION TODAY WITH THE REMOTE POSSIBILITY OF A THUNDERSTORM AT
KRDM AND KBDN IN THE AFTERNOON AND EVENING...THEN PARTIAL CLEARING
OVERNIGHT. WESTERLY WINDS WILL BE INCREASE SLIGHTLY TODAY AT 10 TO
20 MPH THEN DECREASE OVERNIGHT.
&&
.PREV DISC... /ISSUED 255 AM PDT THU SEP 18 2014/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...AN UPPER LEVEL TROUGH
IS NEAR THE COAST AS IT SLOWLY SHIFTS EASTWARD. THE TROUGH IS
SPLITTING AS IT MOVES INLAND WITH THE NORTHERN SECTION IN WASHINGTON
AND THE SOUTHERN SECTION IN CALIFORNIA. THERE ARE TWO BANDS OF
PRECIPITATION ON RADAR AND MODELS. ONE IS NEAR THE CASCADES ON THE
EAST SIDE OF THE TROUGH AXIS AND THE SECOND ONE IS IN EASTERN GRANT
COUNTY...WALLOWA COUNTY...AND BAKER COUNTY. HRRR SHOWS THE FIRST
BAND REMAINING IN CENTRAL/NORTH CENTRAL OREGON AND CENTRAL
WASHINGTON THIS MORNING. THE SECOND BAND IS ASSOCIATED WITH A JET
STREAK. HRRR SHOWS THIS BAND REMAINING SEPARATE AND MOVING NORTHEAST
OUT OF THE OREGON BY 16Z. THE MORNING FORECAST HAS THE TWO SEPARATE
BANDS...THEN THE FIRST BAND WILL SPREAD ACROSS CENTRAL TO NORTHEAST
OREGON AS THE TROUGH AXIS MOVES ACROSS EASTERN WASHINGTON AND OREGON
THIS AFTERNOON. THE BEST INSTABILITY WILL MOVE FROM CENTRAL TO
NORTHEAST OREGON WHERE THE DIFFLUENCE FROM THE SPLITTING TROUGH IS
ADDED TO THE INSTABILITY AHEAD OF THE TROUGH. ISOLATED THUNDERSTORMS
MAY DEVELOP IN THIS REGION DURING THE AFTERNOON AND EARLY EVENING.
THE TROUGH AXIS WILL BE IN IDAHO BY 6Z/2300 PDT WITH RAIN SHOWERS
ENDING EXCEPT FOR OROGRAPHIC SHOWERS NEAR THE CASCADE CREST. FRIDAY
AND SATURDAY THE UPPER LEVEL RIDGE WILL BUILD OVER THE PACIFIC
NORTHWEST WITH CLEARING SKIES AND WARMING DAYTIME TEMPERATURES.
COONFIELD
LONG TERM...SUNDAY THROUGH WEDNESDAY...00Z MODEL RUNS INDICATE VERY
SIMILAR SOLUTIONS OVER FORECAST AREA AND NORTHEAST PACIFIC WITH A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUING OVER THE PACIFIC
NORTHWEST SUNDAY AND MONDAY. MODELS SHOW CONSISTENT SOLUTIONS FOR
TUESDAY AS WELL WITH THE RIDGE MOVING EAST INTO THE NORTHERN PLAINS
BY DAYBREAK TUESDAY AS THE NEXT LONGWAVE TROUGH SPREADS EASTWARD TO
130-140W. THE GFS IS MORE PROGRESSIVE IN TAKING THE AXIS OF AN OPEN
LONGWAVE TROUGH TO 132W BY TUESDAY AFTERNOON WHEREAS THE ECMWF KEEPS
THE LOWEST HEIGHTS IN THE OVERALL TROUGH NEAR 140W WHERE A CLOSED
LOW WITH MUCH LOWER HEIGHTS DEVELOPS IN THE ECMWF SOLUTION. BOTH GFS
AND ECMWF SHOW A VERY WEAK DISTURBANCE MOVING THROUGH FORECAST AREA
MONDAY NIGHT AND TUESDAY SO I HAVE INCREASED POPS A TAD TO SLIGHT
CHANCE FOR POSSIBLE ISOLATED LIGHT SHOWERS IN THE BLUE MOUNTAINS
MONDAY NIGHT AND TUESDAY. THE TROUGH APPROACHES THE COAST TUESDAY
NIGHT AND SPREADS INCREASING CLOUDS, MOISTURE, AND RAIN TO THE
CASCADES JUST BEFORE DAYBREAK ON WEDNESDAY. THE PRECIPITATION
SPREADS ACROSS FORECAST AREA WEDNESDAY MORNING. AS ALREADY
MENTIONED, THE GFS IS FASTER IN TERMS OF BRINGING THE TROUGH AXIS TO
THE COAST BY LATE WEDNESDAY MORNING WHILE THE ECMWF KEEPS THE TROUGH
AXIS WELL OFFSHORE. THIS PHASING DIFFERENCE BETWEEN THE TWO MODELS
ON WEDNESDAY WITH RESPECT TO THE PLACEMENT OF THE TROUGH AXIS
RESULTS IN THE ECMWF TAKING LONGER TO SPREAD RAIN TO THE BLUE
MOUNTAINS UNTIL LATE WEDNESDAY NIGHT OR THURSDAY MORNING. AS SUCH
HAVE LOWER CONFIDENCE IN POP FORECAST FOR WEDNESDAY IN THE EASTERN
SECTIONS OF FORECAST AREA. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 80 55 80 52 / 20 10 0 0
ALW 83 61 80 57 / 20 10 0 0
PSC 85 57 85 51 / 10 10 0 0
YKM 80 56 84 54 / 20 10 0 0
HRI 83 55 85 48 / 10 10 0 0
ELN 80 57 83 52 / 20 10 0 0
RDM 76 43 79 40 / 20 20 0 0
LGD 81 51 79 44 / 20 10 0 0
GCD 78 49 81 47 / 20 10 0 0
DLS 78 58 83 52 / 30 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
89/99/99
AREA FORECAST DISCUSSION
NWS PENDLETON OR
859 AM PDT THU SEP 18 2014
.UPDATE...THE CURRENT FORECAST REMAINS ON TRACK WITH JUST A FEW
MINOR ADJUSTMENTS TO THE TODAY AND THIS EVENING PERIOD. HAVE MADE
SOME MINOR ADJUSTMENTS TO THE HIGHS TODAY...MAINLY ACROSS THE
WESTERN PORTION OF THE CWA.
EXPECT WINDY CONDITIONS ALONG THE KITTITAS VALLEY AND THE COLUMBIA
RIVER GORGE TODAY...WITH THE BASIN AND FOOTHILL AREAS BEING BREEZY.
EXPECT 20 MPH GUSTING TO 30 MPH FOR THE GORGE AND THE KITTIAS
VALLEY...WITH 15 MPH GUSTING 25 MPH ELSEWHERE ACROSS THE BASIN.
WINDS SHOULD BEGIN TO PICK UP AFTER NOON TODAY...AND ARE EXPECTED TO
BE STRONGEST AROUND 5 PM DIMINISHING AFTER MIDNIGHT.
HAVE ALSO PULLED BACK ON POPS TO GO MOSTLY SLIGHT CHANCE EAST OF THE
CASCADE CREST. THE SPLIT FLOW WILL CUT OFF MOST OF THE MOISTURE
FROM THE TROUGH THAT WILL PROGRESS SOUTH ALONG THE CALIFORNIA COAST
TODAY INTO TONIGHT. SLIGHT CHANCE UPSLOPE SHOWERS CAN BE EXPECTED
ACROSS THE NORTHEAST MOUNTAINS TODAY AND THIS EVENING. HAVE
MENTIONED SLIGHT CHANCE THUNDER ACROSS THE NORTHEAST MOUNTAINS
THROUGH 5 PM...AS IT STILL CAN`T BE RULED OUT. BUT ONCE THE WEST
NORTHWEST FLOW SETS IN THIS EVENING...INSTABILITY WILL BE VERY
LIMITED. SO HAVE PULLED BACK ON THE THUNDER POTENTIAL TO JUST THE
EAGLE CAPS...SOUTHERN GRANT...CROOK...AND DESCHUTES COUNTY FROM 5 TO
8 PM THIS EVENING. WEBER
&&
.PREV DISC... /ISSUED 255 AM PDT THU SEP 18 2014/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...AN UPPER LEVEL TROUGH
IS NEAR THE COAST AS IT SLOWLY SHIFTS EASTWARD. THE TROUGH IS
SPLITTING AS IT MOVES INLAND WITH THE NORTHERN SECTION IN WASHINGTON
AND THE SOUTHERN SECTION IN CALIFORNIA. THERE ARE TWO BANDS OF
PRECIPITATION ON RADAR AND MODELS. ONE IS NEAR THE CASCADES ON THE
EAST SIDE OF THE TROUGH AXIS AND THE SECOND ONE IS IN EASTERN GRANT
COUNTY...WALLOWA COUNTY...AND BAKER COUNTY. HRRR SHOWS THE FIRST
BAND REMAINING IN CENTRAL/NORTH CENTRAL OREGON AND CENTRAL
WASHINGTON THIS MORNING. THE SECOND BAND IS ASSOCIATED WITH A JET
STREAK. HRRR SHOWS THIS BAND REMAINING SEPARATE AND MOVING NORTHEAST
OUT OF THE OREGON BY 16Z. THE MORNING FORECAST HAS THE TWO SEPARATE
BANDS...THEN THE FIRST BAND WILL SPREAD ACROSS CENTRAL TO NORTHEAST
OREGON AS THE TROUGH AXIS MOVES ACROSS EASTERN WASHINGTON AND OREGON
THIS AFTERNOON. THE BEST INSTABILITY WILL MOVE FROM CENTRAL TO
NORTHEAST OREGON WHERE THE DIFFLUENCE FROM THE SPLITTING TROUGH IS
ADDED TO THE INSTABILITY AHEAD OF THE TROUGH. ISOLATED THUNDERSTORMS
MAY DEVELOP IN THIS REGION DURING THE AFTERNOON AND EARLY EVENING.
THE TROUGH AXIS WILL BE IN IDAHO BY 6Z/2300 PDT WITH RAIN SHOWERS
ENDING EXCEPT FOR OROGRAPHIC SHOWERS NEAR THE CASCADE CREST. FRIDAY
AND SATURDAY THE UPPER LEVEL RIDGE WILL BUILD OVER THE PACIFIC
NORTHWEST WITH CLEARING SKIES AND WARMING DAYTIME TEMPERATURES.
COONFIELD
LONG TERM...SUNDAY THROUGH WEDNESDAY...00Z MODEL RUNS INDICATE VERY
SIMILAR SOLUTIONS OVER FORECAST AREA AND NORTHEAST PACIFIC WITH A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUING OVER THE PACIFIC
NORTHWEST SUNDAY AND MONDAY. MODELS SHOW CONSISTENT SOLUTIONS FOR
TUESDAY AS WELL WITH THE RIDGE MOVING EAST INTO THE NORTHERN PLAINS
BY DAYBREAK TUESDAY AS THE NEXT LONGWAVE TROUGH SPREADS EASTWARD TO
130-140W. THE GFS IS MORE PROGRESSIVE IN TAKING THE AXIS OF AN OPEN
LONGWAVE TROUGH TO 132W BY TUESDAY AFTERNOON WHEREAS THE ECMWF KEEPS
THE LOWEST HEIGHTS IN THE OVERALL TROUGH NEAR 140W WHERE A CLOSED
LOW WITH MUCH LOWER HEIGHTS DEVELOPS IN THE ECMWF SOLUTION. BOTH GFS
AND ECMWF SHOW A VERY WEAK DISTURBANCE MOVING THROUGH FORECAST AREA
MONDAY NIGHT AND TUESDAY SO I HAVE INCREASED POPS A TAD TO SLIGHT
CHANCE FOR POSSIBLE ISOLATED LIGHT SHOWERS IN THE BLUE MOUNTAINS
MONDAY NIGHT AND TUESDAY. THE TROUGH APPROACHES THE COAST TUESDAY
NIGHT AND SPREADS INCREASING CLOUDS, MOISTURE, AND RAIN TO THE
CASCADES JUST BEFORE DAYBREAK ON WEDNESDAY. THE PRECIPITATION
SPREADS ACROSS FORECAST AREA WEDNESDAY MORNING. AS ALREADY
MENTIONED, THE GFS IS FASTER IN TERMS OF BRINGING THE TROUGH AXIS TO
THE COAST BY LATE WEDNESDAY MORNING WHILE THE ECMWF KEEPS THE TROUGH
AXIS WELL OFFSHORE. THIS PHASING DIFFERENCE BETWEEN THE TWO MODELS
ON WEDNESDAY WITH RESPECT TO THE PLACEMENT OF THE TROUGH AXIS
RESULTS IN THE ECMWF TAKING LONGER TO SPREAD RAIN TO THE BLUE
MOUNTAINS UNTIL LATE WEDNESDAY NIGHT OR THURSDAY MORNING. AS SUCH
HAVE LOWER CONFIDENCE IN POP FORECAST FOR WEDNESDAY IN THE EASTERN
SECTIONS OF FORECAST AREA. POLAN
AVIATION...12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NEXT 24 HOURS. THERE MAY BE SOME LIGHT SHOWERS AT
KDLS...KRDM...KBDN...KPDT AND KALW TODAY WITH POSSIBLY A
THUNDERSTORM AT KRDM AND KBDN IN THE AFTERNOON AND EVENING. WINDS
WILL BE GENERALLY LIGHT ALTHOUGH GUSTY AND ERRATIC WINDS ARE LIKELY
NEAR ANY THUNDERSTORMS. CIGS AND VISIBILITIES WILL REMAIN ABOVE VFR
DUE TO THE DRYNESS OF THE AIR MASS IN THE LOWER LEVELS THROUGH THIS
EVENING. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 80 55 80 52 / 20 10 0 0
ALW 83 61 80 57 / 20 10 0 0
PSC 85 57 85 51 / 10 10 0 0
YKM 80 56 84 54 / 20 10 0 0
HRI 83 55 85 48 / 10 10 0 0
ELN 80 57 83 52 / 20 10 0 0
RDM 76 43 79 40 / 20 20 0 0
LGD 81 51 79 44 / 20 10 0 0
GCD 78 49 81 47 / 20 10 0 0
DLS 78 58 83 52 / 30 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
89/99/99
AREA FORECAST DISCUSSION
NWS PENDLETON OR
255 AM PDT THU SEP 18 2014
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...AN UPPER LEVEL TROUGH
IS NEAR THE COAST AS IT SLOWLY SHIFTS EASTWARD. THE TROUGH IS
SPLITTING AS IT MOVES INLAND WITH THE NORTHERN SECTION IN WASHINGTON
AND THE SOUTHERN SECTION IN CALIFORNIA. THERE ARE TWO BANDS OF
PRECIPITATION ON RADAR AND MODELS. ONE IS NEAR THE CASCADES ON THE
EAST SIDE OF THE TROUGH AXIS AND THE SECOND ONE IS IN EASTERN GRANT
COUNTY...WALLOWA COUNTY...AND BAKER COUNTY. HRRR SHOWS THE FIRST
BAND REMAINING IN CENTRAL/NORTH CENTRAL OREGON AND CENTRAL
WASHINGTON THIS MORNING. THE SECOND BAND IS ASSOCIATED WITH A JET
STREAK. HRRR SHOWS THIS BAND REMAINING SEPARATE AND MOVING NORTHEAST
OUT OF THE OREGON BY 16Z. THE MORNING FORECAST HAS THE TWO SEPARATE
BANDS...THEN THE FIRST BAND WILL SPREAD ACROSS CENTRAL TO NORTHEAST
OREGON AS THE TROUGH AXIS MOVES ACROSS EASTERN WASHINGTON AND OREGON
THIS AFTERNOON. THE BEST INSTABILITY WILL MOVE FROM CENTRAL TO
NORTHEAST OREGON WHERE THE DIFFLUENCE FROM THE SPLITTING TROUGH IS
ADDED TO THE INSTABILITY AHEAD OF THE TROUGH. ISOLATED THUNDERSTORMS
MAY DEVELOP IN THIS REGION DURING THE AFTERNOON AND EARLY EVENING.
THE TROUGH AXIS WILL BE IN IDAHO BY 6Z/2300 PDT WITH RAIN SHOWERS
ENDING EXCEPT FOR OROGRAPHIC SHOWERS NEAR THE CASCADE CREST. FRIDAY
AND SATURDAY THE UPPER LEVEL RIDGE WILL BUILD OVER THE PACIFIC
NORTHWEST WITH CLEARING SKIES AND WARMING DAYTIME TEMPERATURES.
COONFIELD
.LONG TERM...SUNDAY THROUGH WEDNESDAY...00Z MODEL RUNS INDICATE VERY
SIMILAR SOLUTIONS OVER FORECAST AREA AND NORTHEAST PACIFIC WITH A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE CONTINUING OVER THE PACIFIC
NORTHWEST SUNDAY AND MONDAY. MODELS SHOW CONSISTENT SOLUTIONS FOR
TUESDAY AS WELL WITH THE RIDGE MOVING EAST INTO THE NORTHERN PLAINS
BY DAYBREAK TUESDAY AS THE NEXT LONGWAVE TROUGH SPREADS EASTWARD TO
130-140W. THE GFS IS MORE PROGRESSIVE IN TAKING THE AXIS OF AN OPEN
LONGWAVE TROUGH TO 132W BY TUESDAY AFTERNOON WHEREAS THE ECMWF KEEPS
THE LOWEST HEIGHTS IN THE OVERALL TROUGH NEAR 140W WHERE A CLOSED
LOW WITH MUCH LOWER HEIGHTS DEVELOPS IN THE ECMWF SOLUTION. BOTH GFS
AND ECMWF SHOW A VERY WEAK DISTURBANCE MOVING THROUGH FORECAST AREA
MONDAY NIGHT AND TUESDAY SO I HAVE INCREASED POPS A TAD TO SLIGHT
CHANCE FOR POSSIBLE ISOLATED LIGHT SHOWERS IN THE BLUE MOUNTAINS
MONDAY NIGHT AND TUESDAY. THE TROUGH APPROACHES THE COAST TUESDAY
NIGHT AND SPREADS INCREASING CLOUDS, MOISTURE, AND RAIN TO THE
CASCADES JUST BEFORE DAYBREAK ON WEDNESDAY. THE PRECIPITATION
SPREADS ACROSS FORECAST AREA WEDNESDAY MORNING. AS ALREADY
MENTIONED, THE GFS IS FASTER IN TERMS OF BRINGING THE TROUGH AXIS TO
THE COAST BY LATE WEDNESDAY MORNING WHILE THE ECMWF KEEPS THE TROUGH
AXIS WELL OFFSHORE. THIS PHASING DIFFERENCE BETWEEN THE TWO MODELS
ON WEDNESDAY WITH RESPECT TO THE PLACEMENT OF THE TROUGH AXIS
RESULTS IN THE ECMWF TAKING LONGER TO SPREAD RAIN TO THE BLUE
MOUNTAINS UNTIL LATE WEDNESDAY NIGHT OR THURSDAY MORNING. AS SUCH
HAVE LOWER CONFIDENCE IN POP FORECAST FOR WEDNESDAY IN THE EASTERN
SECTIONS OF FORECAST AREA. POLAN
&&
.AVIATION...12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NEXT 24 HOURS. THERE MAY BE SOME LIGHT SHOWERS AT
KDLS...KRDM...KBDN...KPDT AND KALW TODAY WITH POSSIBLY A
THUNDERSTORM AT KRDM AND KBDN IN THE AFTERNOON AND EVENING. WINDS
WILL BE GENERALLY LIGHT ALTHOUGH GUSTY AND ERRATIC WINDS ARE LIKELY
NEAR ANY THUNDERSTORMS. CIGS AND VISIBILITIES WILL REMAIN ABOVE VFR
DUE TO THE DRYNESS OF THE AIR MASS IN THE LOWER LEVELS THROUGH THIS
EVENING. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 82 53 80 52 / 20 10 0 0
ALW 83 59 80 57 / 20 10 0 0
PSC 86 57 85 51 / 10 10 0 0
YKM 82 56 84 54 / 30 10 0 0
HRI 84 54 85 48 / 10 10 0 0
ELN 79 57 83 52 / 30 10 0 0
RDM 76 41 79 40 / 20 20 0 0
LGD 82 50 79 44 / 20 20 0 0
GCD 80 49 81 47 / 20 20 0 0
DLS 79 55 83 52 / 30 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
76/99/99
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1249 AM CDT THU SEP 18 2014
.UPDATE...
UPDATED FOR THE 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 948 PM CDT WED SEP 17 2014/
UPDATE...
DECREASED POPS OVERNIGHT DUE TO CURRENT CONDITIONS. STILL
CONFIDENT IN THE HRRR SOLUTION OF SHOWERS IN THE MORNING.
INCREASED CLOUD COVER THROUGHOUT THE DAY TOMORROW TO REFLECT THE
INCREASED MOISTURE ASSOCIATED WITH THE DISTURBANCE APPROACHING THE
AREA.
JPM3
&&
.PREV DISCUSSION... /ISSUED 321 PM CDT WED SEP 17 2014/
NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE MIDSOUTH THROUGH EARLY
FRIDAY. IN THE SHORT TERM... AN MCS OVER NORTHERN AR WILL DRIFT SE
THIS EVENING. UPSTREAM REAR PROPAGATION TENDENCIES THIS EVENING
MAY RESULT IN ADDITIONAL SHOWERS AND THUNDERSTORMS EVENTUALLY
MOVING INTO EASTERN AR AND PERHAPS WEST TN AND NORTHWEST MS
OVERNIGHT.
SHORT TERM MODELS VARY A BIT WITH UPSTREAM CONVECTIVE INITIATION
EARLY ON THURSDAY. GOES WATER VAPOR IMAGERY SHOWED A WEAK SHORTWAVE
MOVING INTO THE WESTERN NEBR PANHANDLE THAT COULD HELP ENHANCE
CONVECTION OVER THE OZARK PLATEAU AND PERHAPS PORTIONS OF THE
MIDSOUTH ON THURSDAY.
BY FRIDAY... AN UPPER LEVEL HEIGHT RIDGE WILL MOVE INTO THE LOWER
MS RIVER VALLEY FROM THE SOUTHERN PLAINS. RESIDUAL MOISTURE FROM
TROPICAL DEPRESSION ODILE WILL OVERRIDE THE TOP OF THE RIDGE...
EVENTUALLY CONSOLIDATING INTO THE BASE OF A NORTHERN BRANCH
LONGWAVE TROF DROPPING INTO TO THE OHIO VALLEY. THIS MOISTURE WILL
MAKE A BRIEF APPEARANCE IN THE MIDSOUTH ON SUNDAY... FOLLOWED BY
DRY NORTHWEST FLOW ALOFT. 12Z ECMWF AND GFS WERE IN GOOD AGREEMENT
FOR THE SUNDAY THROUGH TUESDAY PERIODS.
UPPER HEIGHTS WILL BUILD AGAIN TOWARD THE MIDDLE PART OF NEXT
WEEK...AS THE EASTERN CONUS LONGWAVE TROF LIFTS OUT TO CANADIAN
MARITIMES. A WEAK SLOW MOVING TROF OVER THE SOUTHERN PLAINS WILL
KEEP RAIN CHANCES WELL TO THE WEST...WHILE DRIER LOW LEVELS AND
UPPER RIDGING LIMIT MIDWEEK RAIN CHANCES FOR THE MIDSOUTH.
PWB
&&
.AVIATION...
06Z TAF SET
MODELS INDICATING REDEVELOPMENT OF SHRAS/TSRAS ACROSS SW MO
OVERNIGHT. THUS FAR ONE CELL HAS DEVELOPED BUT IF MORE DOES DEVELOP
THE ACTIVITY COULD PUSH INTO KJBR AROUND 7-8Z...POSSIBLY GETTING TO
KMEM AROUND 9-10Z. WILL CONTINUE MENTION OF VCTS WORDING. CIGS WILL
GRADUALLY LOWER TO MVFR TONIGHT. SOME PATCHY FOG COULD DEVELOP AT
KMKL AS WELL. SHOULD RETURN TO VFR DURING THE MORNING HOURS.
GENERALLY LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.
KRM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1132 PM CDT WED SEP 17 2014
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
SOME ISO LIGHT NOTED ACROSS MID SOUTH...BUT WITH POTENTIAL IMPACTS MINIMAL
IF DEVELOPMENT NEAR TAF SITES...WILL CONTINUE NOT TO MENTION. NWLY FLOW
ALOFT STILL LOOKS LIKE IT WILL SUPPORT PROGRESSION OF MID TO UPPER LEVEL
MOISTURE ACROSS MID STATE THRU 18/12Z...WITH THE POTENTIAL OF CLRING
BEHIND SHORTWAVE PASSAGE NW TO SE...AND ALONG WITH LIGHT TO CALM WINDS...
SUPPORTING MVFR TO IFR FOG TAF SITES THRU 18/14Z. EXPECT DRIER AIRMASS TO
WORK INTO MID STATE THRU 19/01Z WITH DIURNAL SCT CU/SCT CI IN NWLY FLOW
ALOFT. DRY NW FLOW ALOFT/SFC RIDGING SUPPORT SKC/VFR CONDITIONS TILL 19/06Z.
&&
.PREV DISCUSSION.../ISSUED 746 PM CDT WED SEP 17 2014/
DISCUSSION...
IMPULSE WORKING SOUTHEASTWARD ACROSS NORTHERN AR AT THIS TIME. MID
AND HIGH LEVEL CLOUDINESS DOES EXTEND EASTWARD ACROSS THE MID
STATE WITH LOW CLOUDS BACK ACROSS MISSOURI. LATEST HRRR IS
OVERDOING THE CONVECTION FOR THIS EVENING. IN FACT...NO
PRECIPITATION IS INDICATED ACROSS THE MID STATE CURRENTLY.
MODELS DO SHOW...HOWEVER...A RETURN OF MOISTURE AT THE 700 MB TO
850 MB LEVEL TOWARD AND BEYOND 06Z. LIGHT QPF IS HINTED TOWARD BY
THE MODELS AFTER 06Z TONIGHT...MAINLY WESTERN AREAS. THIS IS IN
LINE WITH THE CURRENT ISC THINKING AS WELL. THUS...WILL REMOVE
EVENING PRECIP BUT INCLUDE A 20 PERCENT CHANCE OF SHOWERS FOR
WESTERN AREAS AFTER MIDNIGHT. WILL ALSO INCREASE THE SKY COVERAGE
TO INCLUDE MOSTLY CLOUDY SKIES FOR A LONGER DURATION ACROSS MUCH
OF THE CENTRAL AND WESTERN AREAS.
AS FOR FOG POTENTIAL...TOVER VALUES WILL BE HIGHER AND ARE NEAR
ZERO FOR THE UPCOMING 12Z PERIOD. ALSO...MODELS ARE NOT AS BULLISH
WITH THE LOW DEWPOINT DEPRESSIONS AROUND 12Z AS WELL. WILL
THEREFORE CONTINUE TO LEAVE THE FOG OUT OF THE FCST.
UPDATE OUT SHORTLY.
PREV DISCUSSION.../ISSUED 705 PM CDT WED SEP 17 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
PER MID TO UPPER LEVEL SHORTWAVE PASSAGE EXPECTED ACROSS MID STATE THRU 18/12Z...
ISO LIGHT SHWR DEVELOPMENT POSSIBLE...BUT LOCATION DEVELOPMENT SO UNCERTAIN/VSBY
IMPACTS MINIMAL...SHOULD HAVE LITTLE IF ANY TAF SITE IMPACTS...THUS DID NOT
MENTION. NWLY FLOW ALOFT SHOULD SUPPORT PROGRESSION OF MID TO UPPER LEVEL
MOISTURE ACROSS MID STATE THRU 18/12Z...WITH THE POTENTIAL OF CLRING BEHIND
SHORTWAVE PASSAGE NW TO SE...AND ALONG WITH LIGHT TO CALM WINDS...SUPPORTING
MVFR TO IFR FOG TAF SITES THRU 18/14Z. EXPECT DRIER AIRMASS TO WORK INTO MID
STATE THRU 18/24Z WITH DIURNAL SCT CU AND SCT CI IN NWLY FLOW ALOFT EXPECTED.
PREV DISCUSSION.../ISSUED 218 PM CDT WED SEP 17 2014/
DISCUSSION...
LATEST INFRARED SHOWING TOPS WARMING ALONG ARKANSAS/MISSOURI BORDER
AS COMPLEX CONTINUES TO DIVE SOUTHEASTWARD IN NORTHWESTERLY FLOW ALOFT.
DEBRIS CLOUDS ALREADY SPILLING INTO MIDDLE TENNESSEE THIS
AFTERNOON. I`M NOT COMFORTABLE LEAVING POPS OUT ALTOGETHER FOR
TONIGHT SINCE MID AND UPPER LEVEL SHORT WAVE IS GOING TO WORK
ACROSS OUR AREA DURING THE NIGHT. EURO AND NAM SHOW SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS AS WE THROUGH THE OVERNIGHT.
MET MOS ACTUALLY HAS A 41 POP WHILE MAV MOS HAS 8 AT NASHVILLE FOR
TONIGHT. H-TRIPLE-R BREAKS SHOWERS AND ISOLATED THUNDER OUT AS
WELL TONIGHT. LATEST SREF RUN KEEPS THUNDER WELL WEST OF MY CWA.
NORTHWESTERLY FLOW WILL CONTINUE WEDNESDAY AND THURSDAY WITH UPPER RIDGE
BUILDING IN OVER THE SOUTHERN U.S. BY FRIDAY WITH WESTERLY BELT ALONG
NORTHERN U.S. CANADIAN BORDER. BELT BUCKLES ON SATURDAY AS UPPER RIDGE
BUILDS UP THROUGH THE ROCKY MOUNTAIN REGION WITH A RATHER DEEP TROUGH
BEING CARVED OUT OVER EASTERN U.S INTO MONDAY. THIS WILL ALLOW FOR
A SERIES OF CANADIAN COLD FRONTS TO MOVE DOWN AND THROUGH THE MID
STATE BEGINNING ON SUNDAY. THIS FRONT WILL BE ACCOMPANIED BY SHOWERS
AND A FEW THUNDERSTORMS SUNDAY INTO MONDAY. ANOTHER FRONT ALBEIT
DRY MOVES DOWN ON TUESDAY OF NEXT WEEK ONLY TO REINFORCE THE CONTINENTAL
POLAR AIRMASS THAT`S ALREADY IN PLACE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1250 PM CDT THU SEP 18 2014
.AVIATION...
TROPICAL MOISTURE PROFILE ACROSS THE AREA NEXT 24 HOURS WITH THE
REMAINS OF TS ODILE EXPECTED TO MOVE SLOWLY FROM SOUTHWEST TO
CENTRAL NEW MEXICO. IN ADDITION TO DEEP MOISTURE...THIS WILL FAVOR
DEEP LIFT AND PREVAILING RAIN AND THUNDER CHANCES FOR KLBB.
AIRMASS JUST WEST AND SOUTHWEST OF KLBB APPEARS TO BE QUICKLY
DESTABILIZING AGAIN EARLY THIS AFTERNOON AND SHOULD SUPPORT
INCREASING THUNDER CHANCES. A WESTWARD MOVING CONVECTIVE OUTFLOW
NOW IN WESTERN OKLAHOMA WILL MOVE THROUGH KCDS BY 20Z AND APPROACH
KLBB 22Z-00Z TIME FRAME WHICH ALSO SHOULD HELP ENHANCE THUNDER
CHANCES. DO NOT ANTICIPATE NECESSARILY CONTINUOUS PRECIPITATION
CHANCES AT KLBB BUT THE BREAKS ARE DIFFICULT TO SUPPORT OR TIME.
MORE STRATIFORM ENVIRONMENT SEEMS MORE LIKELY OVERNIGHT WITH LOW
CEILING AND VISIBILITY RISK KLBB ESPECIALLY AND MOSTLY IFR
POSSIBLY LIFR CONDITIONS. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 1005 AM CDT THU SEP 18 2014/
UPDATE...
THE FLOOD WATCH HAS BEEN EXPANDED EASTWARD TO INCLUDE MOST OF THE
CWA...EXCLUDING HALL AND CHILDRESS COUNTIES. A LARGE AREA OF
MODERATE RAINFALL CONTINUES TO ENVELOP MUCH OF THE FA...WITH
POCKETS OF HEAVY RAIN. IT APPEARS THE HEAVIEST OF THE RAINFALL IS
GOING TO TEND TO CONVERGE ACROSS OUR SOUTHEAST ZONES OVER THE NEXT
COUPLE OF HOURS...AND FOR THIS REASON WE HAVE DECIDED TO EXPAND
THE FLOOD WATCH EASTWARD. POP...WEATHER AND QPF GRIDS WERE ALSO
ADJUSTED GIVEN CURRENT RADAR TRENDS AND HIGH RESOLUTION MODELS. A
MENTION OF HEAVY RAIN WAS ALSO ADDED TO A GOOD CHUNK OF THE AREA
THIS MORNING...WHILE MAINTAINING THE HEAVY RAIN MENTION ACROSS THE
SOUTHEAST ZONES THIS AFTERNOON. UPDATED PRODUCTS HAVE BEEN SENT.
PREV DISCUSSION... /ISSUED 630 AM CDT THU SEP 18 2014/
AVIATION...
FLYING WEATHER FOR VFR PILOTS WILL BE A DISAPPOINTMENT NEXT 24
HOURS. WIDESPREAD RAINFALL WITH EMBEDDED TSTMS WILL LIKELY PERSIST
MUCH OF THE FCST PERIOD. WE MAY SEE SOME PERIOD OF MVFR/VFR AT
KLBB BUT THIS IS LIKELY ONLY TO EXIST BETWEEN STORMS AS WIDESPREAD
RAINFALL IS EXPECTED THIS MORNING WITH PERHAPS AN AFTERNOON BREAK
THEN MORE AGAIN TONIGHT. IFR AIRCRAFT SHOULD BE IMPACTED MUCH LESS
HEAVILY THOUGH MANEUVERING AROUND CONVECTIVE CELLS WILL BE
NECESSARY.
PREV DISCUSSION... /ISSUED 322 AM CDT THU SEP 18 2014/
SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING WEST TO EAST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE
DISTURBANCE PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE
SFC WILL VEER TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD
FRONTAL PASSAGE /WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/.
THIS COLD FRONT WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH
SUNDAY...WITH A NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 63 74 61 82 59 / 60 70 60 30 30
TULIA 64 77 63 80 62 / 50 70 60 50 30
PLAINVIEW 64 77 63 80 62 / 60 70 60 50 30
LEVELLAND 65 76 63 81 63 / 70 70 60 40 40
LUBBOCK 67 77 66 81 65 / 70 70 60 50 40
DENVER CITY 66 78 64 84 63 / 70 70 60 40 40
BROWNFIELD 67 78 64 83 64 / 70 70 60 40 40
CHILDRESS 67 83 67 80 66 / 50 50 60 60 40
SPUR 67 80 65 82 66 / 60 50 60 50 50
ASPERMONT 69 85 69 85 68 / 60 50 60 50 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>044.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1239 PM CDT THU SEP 18 2014
.DISCUSSION...
SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...
AVIATION CONDITIONS WILL BRIEFLY IMPROVE AT KIAH AND KHOU THROUGH
THE EVENING BUT AM EXPECTING CONDS TO DETERIORATE AT KCLL/KUTS AND
KGLS THROUGH THE AFTERNOON AS CONVECTION MOVES TOWARD THE
PERIPHERY OF THE HGX CWA. LEANED TOWARD A HRRR/NAM12 AND RAP BLEND
WHICH SETS UP LOW LEVEL CONVERGENCE WITH EAST WINDS OVER LAND AND
SE WINDS OVER THE WATER. SHRA SHOULD REDEVELOP SOUTH OF I-10
BETWEEN 08-11Z FRIDAY AND EXPAND INLAND. GFS LOOKS TO BE TOO
AGGRESSIVE WITH DRYING FRI MORNING. 43
&&
.PREV DISCUSSION... /ISSUED 1042 AM CDT THU SEP 18 2014/
UPDATE...
ANOTHER DAY OF SLOW-MOVING CLUSTERS OF MODERATE TO HEAVY RAIN
CELLS...WITH EMBEDDED THUNDERSTORMS...THAT HAVE PRODUCED NUISANCE
FLOODING AROUND HOUSTON METRO. COMMUNITIES OF WESTERN HARRIS...
SOUTHEASTERN MONTGOMERY...AND SOUTHERN SAN JACINTO COUNTIES HAVE
RECEIVED THE HIGHEST RAINFALL THIS MORNING. UPPER LAYER SOIL
SATURATION INDICATES THAT THE SOUTHEASTERN CWA ARE THE COUNTIES
THAT CAN PICK UP THE LEAST AMOUNT OF RAINFALL BEFORE DEALING WITH
FLOODING ISSUES. THE CORE RAINS ARE MOVING A LITTLE FASTER OFF TO
THE NORTHEAST AT 15 TO 20 MPH...AND THIS IS THE GOOD NEWS. THE
LESS GOOD NEWS IS THAT THERE IS WESTERN COUNTY PRECIPITATION RE-
DEVELOPMENT...WITH AN APPROACHING NORTH CENTRAL TEXAS SHORTWAVE
DISTURBANCE EMBEDDED WITHIN THE MID-LEVEL SOUTHEASTERLY STEERING
FLOW. THE AIR MASS REMAINS UNCHANGED AND...OTHER THAN SOME BRIEF
MOMENTS OF RESPITE AFTER PASSING RAIN AS THE ATMOSPHERE QUICKLY
RE-CHARGES...THE SITUATION WILL BE OF RETURNING PRECIPITATION. IT
ALL DEPENDS UPON THE NEAR TERM AREAL EXTENT AND IMPACT OF AFTERNOON
RAIN/STORM ACTIVITY OVER THE NEXT 6 HOURS IN DETERMINING WHETHER
THE FLOOD WATCH NEEDS TO BE EXTENDED INTO FRIDAY. RAIN AND OVERCAST
EQUATE TO MANY ONLY ACHIEVING THE MID 80S FOR MAXIMUM TEMPERATURES.
AS OF NOW...IT APPEARS THAT FRIDAY WILL BE A TRANSITION DAY TO
RELATIVELY DRIER WEEKEND CONDITIONS. HIGHER RAIN CHANCES SHOULD BE
FOCUSED ALONG THE COAST AND POINTS SOUTHWESTWARD...OR WHERE THE
HIGHER MOISTURE RESIDES. THIS ASSUMPTION IS BASED UPON A DRIER AIR
AIR MASS OVER THE SABINE REGION MODELED TO PUSH INTO THE EASTERN
CWA BEHIND A VERY WEAK NORTHEASTERN BOUNDARY PASSAGE EARLY FRIDAY
MORNING. 31
PREV DISCUSSION... /ISSUED 455 AM CDT THU SEP 18 2014/
DISCUSSION...
WET FCST TO CONTINUE TODAY BUT WITH A CONTINUED THREAT OF FLOODING.
GROUNDS WET FROM RAINS THE PREVIOUS FEW DAYS ALONG WITH THE POTENTIAL
OF ADDITIONAL RAINS TODAY WILL KEEP THE FLOOD WATCH IN PLACE THROUGH
THIS EVENING.
ALREADY SEEING DEVELOPMENT OVER THE NEARSHORE WATERS THIS MORNING
AS THE CONTINUED WAA FLOW COLLIDES WITH THE MORE S/SE MOVING DISTURBANCE
COMING OUT OF SOUTH CENTRAL TX. ALSO SEEING HINTS OF YET ANOTHER
DISTURBANCE TRYING TO DIVE DOWN FROM NORTH TX. THESE SYSTEMS COMBINED
WITH THIS STILL VERY MOIST/TROPICAL AIR MASS ALREADY IN PLACE SHOULD
PRODUCE WIDESPREAD CONVECTION ACROSS THE CWA THRU THIS AFTN/EVE.
PER THE LATEST MODEL RUNS...THE REST OF THE WEEK/WEEKEND FORECAST SHOULD
SEE SOME DRYING BUT CONSENSUS NOT AS STRONG WITH THIS NEXT COLD FRONT
EARLY NEXT WEEK. PROGS APPEAR TO BE HAVING ISSUES WITH THE HANDLING
OF THE REMNANTS OF ODILE AND MAY BE EXAGGERATING ITS IMPACT ON THE
MAIN UPPER FLOW/PATTERN. AS SUCH WILL NOT BE CHANGING THE EXTENDED
FCSTS (TOO MUCH) OF FROPA MON (ALONG WITH COOLER AND DRIER CONDTIONS
NEXT WEEK). 41
MARINE...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS MORNING
AND MAY HAVE A CLUSTER MOVE INTO THE COASTAL WATERS THIS AFTERNOON
WITH GUSTY WINDS. SOUTHEAST WINDS WILL BECOME MORE EASTERLY ON
FRIDAY...AND INCREASE FRIDAY NIGHT AND SATURDAY. WEAK HIGH
PRESSURE SETTLES OVER SETX/LA AND WINDS SHOULD SLOWLY RELAX ON
MONDAY. A COLD FRONT SHOULD (IF THE ECMWF IS CORRECT-FAVORING IT
ATTM) MOVE INTO THE COASTAL WATERS ON TUESDAY OF COURSE DEPENDING
ON HOW WELL THE MODELS HANDLE ODILE AND THE NEXT TROUGH THROUGH
THE EASTERN U.S.. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 71 88 71 91 73 / 60 50 20 30 20
HOUSTON (IAH) 71 88 72 90 74 / 60 70 20 30 20
GALVESTON (GLS) 77 86 79 88 79 / 60 60 30 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...31
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1231 PM CDT THU SEP 18 2014
.DISCUSSION...UPDATED FOR 18Z AVIATION.
&&
.AVIATION...VICINITY THUNDERSTORMS FOR KVCT AND KCRP THIS
AFTERNOON DUE TO ONGOING AND ANTICIPATED CONVECTIVE ACTIVITY.
RAIN CHANCES ARE HIGHER FOR KVCT. CONSIDERED PUTTING A MENTION OF
VCTS OR VCSH AT KALI...BUT WITH POP GRIDS SITTING AT 20% LEFT OUT
OF THE TAF FOR CONSISTENCY`S SAKE. ACTIVITY WILL TAPER OFF AFTER
SUNSET...LEAVING CIRRUS BLOWOFF IN ITS WAKE...PARTICULARLY OVER
THE EASTERN THREE TERMINALS. VFR CIGS AND VIS WILL LIKELY GIVE WAY
TO MVFR CIGS/VIS AT KLRD AND KVCT. HAVE INCLUDED TEMPO IFR AT KALI
DUE TO TRENDS OVER THE PAST COUPLE OF DAYS AND NO SIGNIFICANT
CHANGES TO THE SYNOPTIC PATTERN.
&&
.PREV DISCUSSION... /ISSUED 639 AM CDT THU SEP 18 2014/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...CONVECTION TO THE NNW OF THE VCT TERMINAL CONTINUES
TO SINK TO THE SSE THIS MORNING. HAVE INCLUDED VCSH REMARKS AS
CONFIDENCE IS NOT HIGH THAT THIS ACTIVITY WILL DIRECTLY IMPACT THE
TERMINAL. INTERMITTENT MVFR CIGS/VSBYS WILL BE POSSIBLE AT ALI/LRD
FOR A FEW HOURS THIS MORNING BEFORE A RETURN TO VFR CONDITIONS.
WEAK S/W TROUGH WILL CONTINUE TO SLIDE TO THE SE TODAY...WITH
ADDITIONAL CHANCES FOR SHOWERS AND STORMS. HAVE INCLUDED VCTS
REMARKS AT ALI/CRP/VCT WITH BEST CHANCES AT THE VCT TAF SITE.
PREV DISCUSSION... /ISSUED 416 AM CDT THU SEP 18 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...AREA OF SLOW MOVING SHOWERS
AND THUNDERSTORMS ASSOCIATED WITH SHORTWAVE TROUGH CONTINUES TO
SLOW SAG TO SOUTH THIS MORNING. LATEST HRRR KEEPS THIS ACTIVITY
NORTH OF THE REGION AS THE MORNING PROGRESSES...BUT WILL CONTINUE
TO MONITOR TRENDS WITH THIS COMPLEX. UPPER DISTURBANCE WILL SHIFT
TO THE SOUTHEAST TODAY. THE BEST SUPPORT AND LOW LEVEL CONVERGENCE
WILL REMAIN OVER THE VICTORIA CROSSROADS REGION...AND HAVE PLACED
THE HIGHEST POPS OVER THIS AREA. FURTHER TO THE WEST AND SOUTHWEST
SUFFICIENT MOISTURE WILL REMAIN IN PLACE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS. AS WITH THE LAST SEVERAL DAYS...THREAT
FOR LOCALLY HEAVY RAIN WILL BE POSSIBLE. PW VALUES WILL REMAIN AT
OR ABOVE 2 INCHES TONIGHT INTO FRIDAY. ANOTHER WEAK DISTURBANCE IN
NW FLOW ALOFT WILL MOVE ACROSS CENTRAL TEXAS ON FRIDAY...RESULTING
IN ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. TEMPERATURES
TODAY AND FRIDAY WILL RANGE FROM THE MIDDLE 90S OVER THE RIO
GRANDE PLAINS WITH UPPER 80S TO LOWER 90S OVER THE VICTORIA
CROSSROADS WHERE BETTER CHANCES OF RAIN WILL EXIST.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...SURFACE HIGH PRESSURE
BEGINS TO NUDGE INTO THE REGION FROM THE NORTHEAST WITH PWATS
EXPECTED TO SLOWLY DECLINE THROUGH THE WEEKEND. NONETHELESS...THERE
WILL STILL BE ENOUGH MOISTURE AVAILABLE TO LEAD TO ISOLATED TO
SCATTERED DIURNAL ACTIVITY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
CONCERNING THE ADVERTISED COLD FRONT NEXT WEEK...MODEL DISAGREEMENTS
CONTINUE. THE NEXT UPPER TROUGH WILL SWING EAST THROUGH THE CENTRAL
PLAINS WITH THE ASSOCIATED FRONTAL BOUNDARY TO FOLLOW. THE ECMWF
KEEPS THE MAIN TROUGH WELL TO THE NORTH WHICH WOULD SUGGEST LITTLE
TO NO AFFECT FROM THE BOUNDARY. HOWEVER THE GFS AND CMC MAINTAIN A
SLIGHTLY SOUTHERN POSITION WHICH WITH THE AIDE OF A SURFACE LOW
ACROSS THE CENTRAL PLAINS...WOULD HELP ELONGATE THE FRONTAL BOUNDARY
INTO SOUTH TEXAS. WITH A MORE NORTH TO SOUTH FLOW IN
MIDLEVELS...WILL CONTINUE TO BRING THE FRONT THROUGH THE REGION
MONDAY NIGHT/TUESDAY KEEPING A SLIGHT CHANCE THROUGH TUESDAY BEFORE
DRYING THINGS OUT FOR THE REST OF THE WEEK. AS FOR
TEMPERATURES...KEPT NEAR TO SLIGHTLY ABOVE GUIDANCE THROUGH THE
PERIOD...WITH THE EXCEPTION OF COOLER CONDITIONS WITH THE FRONTAL
BOUNDARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 77 91 76 91 75 / 20 40 20 20 20
VICTORIA 75 91 74 93 75 / 30 50 10 30 10
LAREDO 77 96 78 96 78 / 20 30 20 30 20
ALICE 76 93 74 93 75 / 20 40 10 30 10
ROCKPORT 78 90 78 90 78 / 30 40 20 20 20
COTULLA 76 95 76 96 76 / 30 30 20 30 10
KINGSVILLE 76 93 75 93 75 / 20 40 10 30 10
NAVY CORPUS 80 89 79 91 79 / 20 40 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
IB/90...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1005 AM CDT THU SEP 18 2014
.UPDATE...
THE FLOOD WATCH HAS BEEN EXPANDED EASTWARD TO INCLUDE MOST OF THE
CWA...EXCLUDING HALL AND CHILDRESS COUNTIES. A LARGE AREA OF
MODERATE RAINFALL CONTINUES TO ENVELOP MUCH OF THE FA...WITH
POCKETS OF HEAVY RAIN. IT APPEARS THE HEAVIEST OF THE RAINFALL IS
GOING TO TEND TO CONVERGE ACROSS OUR SOUTHEAST ZONES OVER THE NEXT
COUPLE OF HOURS...AND FOR THIS REASON WE HAVE DECIDED TO EXPAND
THE FLOOD WATCH EASTWARD. POP...WEATHER AND QPF GRIDS WERE ALSO
ADJUSTED GIVEN CURRENT RADAR TRENDS AND HIGH RESOLUTION MODELS. A
MENTION OF HEAVY RAIN WAS ALSO ADDED TO A GOOD CHUNK OF THE AREA
THIS MORNING...WHILE MAINTAINING THE HEAVY RAIN MENTION ACROSS THE
SOUTHEAST ZONES THIS AFTERNOON. UPDATED PRODUCTS HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 630 AM CDT THU SEP 18 2014/
AVIATION...
FLYING WEATHER FOR VFR PILOTS WILL BE A DISAPPOINTMENT NEXT 24
HOURS. WIDESPREAD RAINFALL WITH EMBEDDED TSTMS WILL LIKELY PERSIST
MUCH OF THE FCST PERIOD. WE MAY SEE SOME PERIOD OF MVFR/VFR AT
KLBB BUT THIS IS LIKELY ONLY TO EXIST BETWEEN STORMS AS WIDESPREAD
RAINFALL IS EXPECTED THIS MORNING WITH PERHAPS AN AFTERNOON BREAK
THEN MORE AGAIN TONIGHT. IFR AIRCRAFT SHOULD BE IMPACTED MUCH LESS
HEAVILY THOUGH MANEUVERING AROUND CONVECTIVE CELLS WILL BE
NECESSARY.
PREV DISCUSSION... /ISSUED 322 AM CDT THU SEP 18 2014/
SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING WEST TO EAST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE
DISTURBANCE PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE
SFC WILL VEER TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD
FRONTAL PASSAGE /WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/.
THIS COLD FRONT WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH
SUNDAY...WITH A NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 63 74 61 82 / 70 60 70 60 30
TULIA 78 64 77 63 80 / 70 50 70 60 50
PLAINVIEW 78 64 77 63 80 / 90 60 70 60 50
LEVELLAND 77 65 76 63 81 / 80 70 70 60 40
LUBBOCK 78 67 77 65 80 / 90 70 70 60 50
DENVER CITY 77 66 78 64 84 / 80 70 70 60 40
BROWNFIELD 77 67 78 64 83 / 80 70 70 60 40
CHILDRESS 84 67 83 67 80 / 70 50 50 60 60
SPUR 80 67 80 65 82 / 90 60 50 60 50
ASPERMONT 83 69 85 69 85 / 80 60 50 60 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>044.
&&
$$
05/23
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
639 AM CDT THU SEP 18 2014
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...CONVECTION TO THE NNW OF THE VCT TERMINAL CONTINUES
TO SINK TO THE SSE THIS MORNING. HAVE INCLUDED VCSH REMARKS AS
CONFIDENCE IS NOT HIGH THAT THIS ACTIVITY WILL DIRECTLY IMPACT THE
TERMINAL. INTERMITTENT MVFR CIGS/VSBYS WILL BE POSSIBLE AT ALI/LRD
FOR A FEW HOURS THIS MORNING BEFORE A RETURN TO VFR CONDITIONS.
WEAK S/W TROUGH WILL CONTINUE TO SLIDE TO THE SE TODAY...WITH
ADDITIONAL CHANCES FOR SHOWERS AND STORMS. HAVE INCLUDED VCTS
REMARKS AT ALI/CRP/VCT WITH BEST CHANCES AT THE VCT TAF SITE.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT THU SEP 18 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...AREA OF SLOW MOVING SHOWERS
AND THUNDERSTORMS ASSOCIATED WITH SHORTWAVE TROUGH CONTINUES TO
SLOW SAG TO SOUTH THIS MORNING. LATEST HRRR KEEPS THIS ACTIVITY
NORTH OF THE REGION AS THE MORNING PROGRESSES...BUT WILL CONTINUE
TO MONITOR TRENDS WITH THIS COMPLEX. UPPER DISTURBANCE WILL SHIFT
TO THE SOUTHEAST TODAY. THE BEST SUPPORT AND LOW LEVEL CONVERGENCE
WILL REMAIN OVER THE VICTORIA CROSSROADS REGION...AND HAVE PLACED
THE HIGHEST POPS OVER THIS AREA. FURTHER TO THE WEST AND SOUTHWEST
SUFFICIENT MOISTURE WILL REMAIN IN PLACE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS. AS WITH THE LAST SEVERAL DAYS...THREAT
FOR LOCALLY HEAVY RAIN WILL BE POSSIBLE. PW VALUES WILL REMAIN AT
OR ABOVE 2 INCHES TONIGHT INTO FRIDAY. ANOTHER WEAK DISTURBANCE IN
NW FLOW ALOFT WILL MOVE ACROSS CENTRAL TEXAS ON FRIDAY...RESULTING
IN ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. TEMPERATURES
TODAY AND FRIDAY WILL RANGE FROM THE MIDDLE 90S OVER THE RIO
GRANDE PLAINS WITH UPPER 80S TO LOWER 90S OVER THE VICTORIA
CROSSROADS WHERE BETTER CHANCES OF RAIN WILL EXIST.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...SURFACE HIGH PRESSURE
BEGINS TO NUDGE INTO THE REGION FROM THE NORTHEAST WITH PWATS
EXPECTED TO SLOWLY DECLINE THROUGH THE WEEKEND. NONETHELESS...THERE
WILL STILL BE ENOUGH MOISTURE AVAILABLE TO LEAD TO ISOLATED TO
SCATTERED DIURNAL ACTIVITY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
CONCERNING THE ADVERTISED COLD FRONT NEXT WEEK...MODEL DISAGREEMENTS
CONTINUE. THE NEXT UPPER TROUGH WILL SWING EAST THROUGH THE CENTRAL
PLAINS WITH THE ASSOCIATED FRONTAL BOUNDARY TO FOLLOW. THE ECMWF
KEEPS THE MAIN TROUGH WELL TO THE NORTH WHICH WOULD SUGGEST LITTLE
TO NO AFFECT FROM THE BOUNDARY. HOWEVER THE GFS AND CMC MAINTAIN A
SLIGHTLY SOUTHERN POSITION WHICH WITH THE AIDE OF A SURFACE LOW
ACROSS THE CENTRAL PLAINS...WOULD HELP ELONGATE THE FRONTAL BOUNDARY
INTO SOUTH TEXAS. WITH A MORE NORTH TO SOUTH FLOW IN
MIDLEVELS...WILL CONTINUE TO BRING THE FRONT THROUGH THE REGION
MONDAY NIGHT/TUESDAY KEEPING A SLIGHT CHANCE THROUGH TUESDAY BEFORE
DRYING THINGS OUT FOR THE REST OF THE WEEK. AS FOR
TEMPERATURES...KEPT NEAR TO SLIGHTLY ABOVE GUIDANCE THROUGH THE
PERIOD...WITH THE EXCEPTION OF COOLER CONDITIONS WITH THE FRONTAL
BOUNDARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 77 91 76 91 75 / 20 40 20 20 20
VICTORIA 75 91 74 93 75 / 30 50 10 30 10
LAREDO 77 96 78 96 78 / 20 30 20 30 20
ALICE 76 93 74 93 75 / 20 40 10 30 10
ROCKPORT 78 90 78 90 78 / 30 40 20 20 20
COTULLA 76 95 76 96 76 / 30 30 20 30 10
KINGSVILLE 76 93 75 93 75 / 20 40 10 30 10
NAVY CORPUS 80 89 79 91 79 / 20 40 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
630 AM CDT THU SEP 18 2014
.AVIATION...
FLYING WEATHER FOR VFR PILOTS WILL BE A DISAPPOINTMENT NEXT 24
HOURS. WIDESPREAD RAINFALL WITH EMBEDDED TSTMS WILL LIKELY PERSIST
MUCH OF THE FCST PERIOD. WE MAY SEE SOME PERIOD OF MVFR/VFR AT
KLBB BUT THIS IS LIKELY ONLY TO EXIST BETWEEN STORMS AS WIDESPREAD
RAINFALL IS EXPECTED THIS MORNING WITH PERHAPS AN AFTERNOON BREAK
THEN MORE AGAIN TONIGHT. IFR AIRCRAFT SHOULD BE IMPACTED MUCH LESS
HEAVILY THOUGH MANEUVERING AROUND CONVECTIVE CELLS WILL BE
NECESSARY.
&&
.PREV DISCUSSION... /ISSUED 322 AM CDT THU SEP 18 2014/
SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING WEST TO EAST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE
DISTURBANCE PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE
SFC WILL VEER TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD
FRONTAL PASSAGE /WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/.
THIS COLD FRONT WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH
SUNDAY...WITH A NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 63 74 61 82 / 60 60 70 60 30
TULIA 78 64 77 63 80 / 40 50 70 60 50
PLAINVIEW 78 64 77 63 80 / 60 60 70 60 50
LEVELLAND 77 65 76 63 81 / 80 70 70 60 40
LUBBOCK 78 67 77 65 80 / 70 70 70 60 50
DENVER CITY 77 66 78 64 84 / 90 70 70 60 40
BROWNFIELD 77 67 78 64 83 / 90 70 70 60 40
CHILDRESS 84 67 83 67 80 / 40 50 50 60 60
SPUR 80 67 80 65 82 / 60 60 50 60 50
ASPERMONT 83 69 85 69 85 / 60 60 50 60 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>030-033>036-039>042.
&&
$$
99/99/26
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
416 AM CDT THU SEP 18 2014
.SHORT TERM (TODAY THROUGH FRIDAY)...AREA OF SLOW MOVING SHOWERS
AND THUNDERSTORMS ASSOCIATED WITH SHORTWAVE TROUGH CONTINUES TO
SLOW SAG TO SOUTH THIS MORNING. LATEST HRRR KEEPS THIS ACTIVITY
NORTH OF THE REGION AS THE MORNING PROGRESSES...BUT WILL CONTINUE
TO MONITOR TRENDS WITH THIS COMPLEX. UPPER DISTURBANCE WILL SHIFT
TO THE SOUTHEAST TODAY. THE BEST SUPPORT AND LOW LEVEL CONVERGENCE
WILL REMAIN OVER THE VICTORIA CROSSROADS REGION...AND HAVE PLACED
THE HIGHEST POPS OVER THIS AREA. FURTHER TO THE WEST AND SOUTHWEST
SUFFICIENT MOISTURE WILL REMAIN IN PLACE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS. AS WITH THE LAST SEVERAL DAYS...THREAT
FOR LOCALLY HEAVY RAIN WILL BE POSSIBLE. PW VALUES WILL REMAIN AT
OR ABOVE 2 INCHES TONIGHT INTO FRIDAY. ANOTHER WEAK DISTURBANCE IN
NW FLOW ALOFT WILL MOVE ACROSS CENTRAL TEXAS ON FRIDAY...RESULTING
IN ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. TEMPERATURES
TODAY AND FRIDAY WILL RANGE FROM THE MIDDLE 90S OVER THE RIO
GRANDE PLAINS WITH UPPER 80S TO LOWER 90S OVER THE VICTORIA
CROSSROADS WHERE BETTER CHANCES OF RAIN WILL EXIST.
&&
.LONG-TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...SURFACE HIGH PRESSURE
BEGINS TO NUDGE INTO THE REGION FROM THE NORTHEAST WITH PWATS
EXPECTED TO SLOWLY DECLINE THROUGH THE WEEKEND. NONETHELESS...THERE
WILL STILL BE ENOUGH MOISTURE AVAILABLE TO LEAD TO ISOLATED TO
SCATTERED DIURNAL ACTIVITY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
CONCERNING THE ADVERTISED COLD FRONT NEXT WEEK...MODEL DISAGREEMENTS
CONTINUE. THE NEXT UPPER TROUGH WILL SWING EAST THROUGH THE CENTRAL
PLAINS WITH THE ASSOCIATED FRONTAL BOUNDARY TO FOLLOW. THE ECMWF
KEEPS THE MAIN TROUGH WELL TO THE NORTH WHICH WOULD SUGGEST LITTLE
TO NO AFFECT FROM THE BOUNDARY. HOWEVER THE GFS AND CMC MAINTAIN A
SLIGHTLY SOUTHERN POSITION WHICH WITH THE AIDE OF A SURFACE LOW
ACROSS THE CENTRAL PLAINS...WOULD HELP ELONGATE THE FRONTAL BOUNDARY
INTO SOUTH TEXAS. WITH A MORE NORTH TO SOUTH FLOW IN
MIDLEVELS...WILL CONTINUE TO BRING THE FRONT THROUGH THE REGION
MONDAY NIGHT/TUESDAY KEEPING A SLIGHT CHANCE THROUGH TUESDAY BEFORE
DRYING THINGS OUT FOR THE REST OF THE WEEK. AS FOR
TEMPERATURES...KEPT NEAR TO SLIGHTLY ABOVE GUIDANCE THROUGH THE
PERIOD...WITH THE EXCEPTION OF COOLER CONDITIONS WITH THE FRONTAL
BOUNDARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 91 77 91 76 91 / 30 20 40 20 20
VICTORIA 89 75 91 74 93 / 60 30 50 10 30
LAREDO 96 77 96 78 96 / 20 20 30 20 30
ALICE 94 76 93 74 93 / 20 20 40 10 30
ROCKPORT 89 78 90 78 90 / 30 30 40 20 20
COTULLA 94 76 95 76 96 / 20 30 30 20 30
KINGSVILLE 94 76 93 75 93 / 20 20 40 10 30
NAVY CORPUS 89 80 89 79 91 / 30 20 40 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...SHORT TERM
CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
322 AM CDT THU SEP 18 2014
.SHORT TERM...
INTERESTING SHORT TERM TO SAY THE LEAST. H2 RIDGING IS NOTED ON NWP
INITIALIZATION AS WOULD BE EXPECTED ABOVE A VIBRANT TROPICAL
SYSTEM. LOOKING AT H7 AND BELOW...WE SEE A CLOSED LOW STRUCTURE
/WHAT IS LEFT OF ODILE/ WORKING ITS WAY ACROSS SERN AZ. STRONG
MOISTURE ADVECTION IS NOTED ALONG THE EAST SIDE OF THIS FEATURE AND
IS QUITE EVIDENT ON WV AS WELL AS RADAR IMAGERY. IN FACT...THE TSTM
COMPLEX RUNNING FROM THE SIERRA DIABLO MTNS UP INTO THE SACRAMENTOS
IS RATHER HEALTHY FOR THIS TIME OF NIGHT. IT IS FORMED ALONG ONE OF
THE BANDED FEATURES. THE HRRR SEEMS TO BE ONTO SOMETHING AND HAD
CORRECTLY FORECAST THE ESTABLISHMENT OF RAIN SHOWERS ACROSS THE
NORTHERN SOUTH PLAINS. IF THE TRENDS CONTINUE...AS THE SACRAMENTO
RANGE SYSTEM APPROACHES...WE SHOULD SEE WIDESPREAD RAINFALL DEVELOP
BEFORE 12Z ACROSS THE SOUTH PLAINS. WILL CONTINUE TO MONITOR TRENDS
FOR AREAL FLOOD POTENTIAL.
LOOKING AHEAD AFTER 12Z...Q VECTOR ANALYSIS SUGGESTS DECENT LARGE
SCALE LIFT PERSISTING INTO THE EARLY AFTERNOON HOURS ESPECIALLY WEST
OF THE ESCARPMENT. THIS FORCING APPEARS TO WANE DURING THE LATE
AFTERNOON AND EVENING BEFORE RETURNING...ALBEIT MORE
WEAKLY...OVERNIGHT. HOWEVER...MODEST DIURNAL HEATING AND COOLING OF
THE MID LEVEL SHOULD ALLOW FOR LONG/SKINNY CAPE WHICH SHOULD KEEP
LIGHT TO MODERATE CONVECTION GOING THROUGH THE AFTERNOON HOURS.
SO...BOTTOM LINE...WILL CONTINUE TO RAISE POPS ACROSS THE AREA WITH
MOST AREAS CATEGORIZED AS LIKELY. IN REVIEWING NWP DERIVED QPF AND
HPC FCST FIELDS...THIS ASSESSMENT SEEMS TO MATCH UP WELL.
WHILE IT SEEMS TO BE VERY WET THIS SEPTEMBER IN LUBBOCK WITH MANY
DAYS OF RAINFALL...WE ARE STILL ONLY ABOUT ONE QUARTER OF THE WAY TO
THE RECORD RAINFALL OF 2008 WHERE 8.7 INCHES FELL. STILL...WITH
MANY MORE DAYS OF RAINFALL STARING AT US LATER THIS WEEK...WE COULD
SEE THIS CHALLENGED.
GIVEN THE STRONG SIGNAL FOR A PROTRACTED RAIN EVENT...HAVE ELECTED
TO ISSUE AREAL FLOOD WATCH FOR THE COUNTIES GENERALLY WEST OF THE
ESCARPMENT THROUGH 00Z SATURDAY. IT IS ANTICIPATED THAT THIS MAY
HAVE TO BE EXTENDED EASTWARD LATER IN TIME BUT WANT RAISE AWARENESS
THAT THE NEXT FEW DAYS COULD POSE SOME HYDROLOGIC PROBLEMS.
THOUGH...WE CAN USE THE RAIN AFTER THE DEFICIT SINCE LATE 2010.
&&
.LONG TERM...
REMNANTS OF ODILE WAS LOCATED ACROSS SERN AZ/SWRN NM EARLY THIS
MORNING...WITH THE UA RIDGE CENTERED ACROSS ERN OLD MEXICO GUIDING
ODILE/S REMNANTS ENE TO ACROSS THE DESERT SW. CONTINUED AMPLE
MOISTURE PROVIDED BY ODILE AND THE GULF OF MEXICO HAVE WILL RESULT
IN PWATS INCREASING INTO THE 1.50-2.10 INCH RANGE ACROSS THE CWA
TOMORROW THROUGH EARLY WEEKEND...AS THE SAID DISTURBANCE GRADUALLY
PASSES ACROSS THE REGION. BOTH THE NAM AND GFS EXHIBITS THE TRACK OF
THE DISTURBANCE TO MOVE ENE ACROSS NERN NM/WRN PANHANDLES TOMORROW
EVENING...TO ACROSS THE CENTRAL PLAINS LATE TOMORROW NIGHT/EARLY
SATURDAY MORNING WITH A CONTINUED EWRD PROGRESSION /THUS EXITING THE
REGION/. THE CURRENT ECMWF RUN IS QUITE A BIT DIFFERENT FROM THE
PREVIOUS SOLUTIONS AS IT NOT ONLY MOVES THE DISTURBANCE ALMOST
SQUARELY ACROSS THE CWA TOMORROW NIGHT...IT THEN BECOMES
QUASI-STATIONARY THROUGH TUESDAY MORNING WHERE THEREAFTER IT
COMMENCES TO SHIFT EAST OF THE REGION. THE OBVIOUSLY SLOWER ECMWF
SOLUTION WOULD MEAN SHOWERS AND THUNDERSTORMS /WITH MODERATE TO
HEAVY RAINFALL/ LASTING THROUGH TUESDAY MORNING AS AN UPSLOPE SFC
REGIME ENCOMPASSES THE AREA. THIS FORECAST PACKAGE WILL LEAN TOWARDS
THE GFS SOLUTION ATTM...GIVEN IT IS A BIT MORE PERSISTENT FROM MODEL
RUN TO MODEL RUN. THIS WOULD MEAN THAT THE THREAT FOR MODERATE TO
HEAVY RAINFALL MOVING EAST TO WEST WITH TIME...WILL BE BEST FRIDAY
THROUGH SATURDAY MORNING...THUS COINCIDING WITH WHEN THE DISTURBANCE
PASSES NE TOWARDS THE CENTRAL PLAINS. SRLY FLOW AT THE SFC WILL VEER
TO THE NORTH LATE SATURDAY NIGHT COURTESY OF A COLD FRONTAL PASSAGE
/WHICH IS NO LONGER SHOWN VIA THE ECMWF SOLUTION/. THIS COLD FRONT
WILL PROVIDE FOR ADDITIONAL PRECIP CHANCES THROUGH SUNDAY...WITH A
NOTABLE DECLINE NORTH TO SOUTH.
AS AN UA RIDGE MOVES OVERHEAD ON MONDAY...DRYER AIR WILL FILTER IN
AND PROMOTE TOP-DOWN DRYING...WHICH IS THE REASON FOR PWATS
DECLINING A BIT FROM NORTH TO SOUTH THOUGH...AMOUNTS OF 1.00-1.30
INCHES WILL ENDURE. SFC WINDS WILL VEER TO A MORE UPSLOPE SFC
REGIME ON TUESDAY HENCE CAUSING PWATS TO JUMP BACK UP A BIT.
ATTENTION QUICKLY TURNS TO AN UA LOW CURRENTLY OFF THE COAST OF NRN
CA/OR...THAT IS SET TO WEAKEN WHILST PROGRESSING ENE ACROSS THE
CENTRAL ROCKIES EARLY NEXT WEEK...TO ACROSS PANHANDLE REGION/CENTRAL
PLAINS. ADEQUATE ATMOSPHERIC MOISTURE AND INCREASING UL SUPPORT MAY
LEAD TO ANOTHER SHOT AT PRECIP. WILL THEREFORE MAINTAIN MENTIONABLE
POPS ON TUESDAY. WILL OF COURSE NEED TO KEEP AN EYE ON HOW ODILE/S
REMNANTS WILL IN FACT BEHAVE BECAUSE IF THE ECMWF IS CORRECT...POPS
WILL DEFINITELY NEED TO BE RAMPED UP TOWARDS THE END OF THE EXTENDED
FORECAST.
ANTICIPATED CLOUD COVER AND RAINFALL WILL LEAD TO TEMPS 5-7 DEGREES
BELOW SEASONAL NORMS /70S AND 80S/ WITH OVERNIGHT LOWS IN THE 50S
AND 60S.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 63 74 61 82 / 60 60 70 60 30
TULIA 78 64 77 63 80 / 40 50 70 60 50
PLAINVIEW 78 64 77 63 80 / 60 60 70 60 50
LEVELLAND 77 65 76 63 81 / 80 70 70 60 40
LUBBOCK 78 67 77 66 81 / 70 70 70 60 50
DENVER CITY 77 66 78 64 84 / 90 70 70 60 40
BROWNFIELD 77 67 78 64 83 / 90 70 70 60 40
CHILDRESS 84 67 83 67 80 / 40 50 50 60 60
SPUR 80 67 80 65 82 / 60 60 50 60 50
ASPERMONT 83 69 85 69 85 / 60 60 50 60 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
TXZ021>024-027>030-033>036-039>042.
&&
$$
26/29
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1148 PM CDT WED SEP 17 2014
.DISCUSSION...
SEE AVIATION FOR 06Z TAF DISCUSSION.
&&
.AVIATION...
LIGHT SHRA MOVING BACK INTO NORTHERN TERMINALS THIS EVENING
ASSOCIATED WITH CONVECTION TO THE WEST BETWEEN AUS AND ACT. HAVE
SEEN SOME IFR CIGS AT CXO ALREADY THIS EVENING AND STILL THINK
THERE IS SOME POTENTIAL FOR IFR CIGS AT OTHER SITES...PRIMARILY SGR
AND POINTS CXO NORTHWARD. CONVECTION WILL DEVELOP AGAIN EARLY
THURSDAY MORNING WITH SOME HEAVY RAINFALL POSSIBLE DURING THE DAY.
EXACT TIMING OF IMPACTS TO TERMINALS REMAINS SOMEWHAT PROBLEMATIC
BUT COVERAGE WILL BE BEST FROM LATE MORNING THROUGH LATE
AFTERNOON. 38
&&
.PREV DISCUSSION... /ISSUED 1122 PM CDT WED SEP 17 2014/
..HEAVY RAINFALL AND FLOOD THREAT FOR THURSDAY...
UPDATE...
EVENING FORECAST UPDATE...
DISCUSSION...
MANY AREAS HAVE RECEIVED 1 TO 3 INCHES OF RAINFALL THE LAST
COUPLE OF DAYS. THIS HAS SATURATED GROUNDS AND LOWERED FLASH FLOOD
GUIDANCE. SOME AREAS COULD SEE FLOODING WITH AS LITTLE AS 1-2
INCHES ESPECIALLY IF THAT MUCH FELL IN AN HOUR. RIGHT NOW LOOKS
LIKE A SHORT WAVE TROUGH OVER THE TX PANHANDLE SHOULD TRACK
TOWARDS E TX AND ARKLATEX THUR. LARGE SCALE ASCENT SHOULD INCREASE
OVER TOP A TROPICAL AIRMASS CHARACTERIZED BY PRECIP WATER VALUES
AROUND 2.2-2.4 INCHES WHICH IS WELL SUPPORTED BY LCH/CRP 00Z
SOUNDINGS AND GOES PRECIP WATER PRODUCT. SHORT RANGE HI RES MODELS
SHOW RAIN SHIELD OVER C TX MOVING INTO THE REGION THE NEXT FEW HRS
WHICH COULD DUMP LIGHT RAIN. LATEST RUNS OF HRRR SHOW FURTHER
DEVELOPMENT WITH DAY TIME HEATING DURING THE LATE MORNING HRS.
QUITE POSSIBLE THAT THIS ACTIVITY WILL SET THE STAGE FOR FLOODING
WITH STORMS PRODUCING HIGH RAIN RATES OF 2 INCHES AN HR. LATEST
00Z SHOWS A BROAD BAND OF CONVECTION FORMING ACROSS THE AREA FROM
15Z TO 21Z WITH EMBEDDED HIGHER RAINFALL AMOUNTS. THINK COLLEGE
STATION TO HOUSTON WILL BE THE MAIN AREA OF CONCERN WITH AREAS TO
THE NORTH OF THAT LINE STILL UNDER THE THREAT. COASTAL AREAS HAVE
A LOWER THREAT BUT GIVEN ACCESS TO HIGH MOISTURE AND MESOSCALE
FORCING FROM OUTFLOW BOUNDARIES...NO ONE CAN BE RULED OUT OF THE
HEAVY RAINFALL/FLOOD DISCUSSION. FLOOD WATCH WILL CONTINUE UNTIL
7PM CDT THURSDAY AND DO NOT THINK THERE WILL BE ANY ADJUSTMENTS.
39/38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 84 71 87 71 / 60 80 40 50 20
HOUSTON (IAH) 74 83 71 87 72 / 40 80 40 60 20
GALVESTON (GLS) 79 84 77 85 79 / 40 70 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLOOD WATCH THROUGH THURSDAY EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1122 PM CDT WED SEP 17 2014
...HEAVY RAINFALL AND FLOOD THREAT FOR THURSDAY...
.UPDATE...
EVENING FORECAST UPDATE...
&&
.DISCUSSION...
MANY AREAS HAVE RECEIVED 1 TO 3 INCHES OF RAINFALL THE LAST
COUPLE OF DAYS. THIS HAS SATURATED GROUNDS AND LOWERED FLASH FLOOD
GUIDANCE. SOME AREAS COULD SEE FLOODING WITH AS LITTLE AS 1-2
INCHES ESPECIALLY IF THAT MUCH FELL IN AN HOUR. RIGHT NOW LOOKS
LIKE A SHORT WAVE TROUGH OVER THE TX PANHANDLE SHOULD TRACK
TOWARDS E TX AND ARKLATEX THUR. LARGE SCALE ASCENT SHOULD INCREASE
OVER TOP A TROPICAL AIRMASS CHARACTERIZED BY PRECIP WATER VALUES
AROUND 2.2-2.4 INCHES WHICH IS WELL SUPPORTED BY LCH/CRP 00Z
SOUNDINGS AND GOES PRECIP WATER PRODUCT. SHORT RANGE HI RES MODELS
SHOW RAIN SHIELD OVER C TX MOVING INTO THE REGION THE NEXT FEW HRS
WHICH COULD DUMP LIGHT RAIN. LATEST RUNS OF HRRR SHOW FURTHER
DEVELOPMENT WITH DAY TIME HEATING DURING THE LATE MORNING HRS.
QUITE POSSIBLE THAT THIS ACTIVITY WILL SET THE STAGE FOR FLOODING
WITH STORMS PRODUCING HIGH RAIN RATES OF 2 INCHES AN HR. LATEST
00Z SHOWS A BROAD BAND OF CONVECTION FORMING ACROSS THE AREA FROM
15Z TO 21Z WITH EMBEDDED HIGHER RAINFALL AMOUNTS. THINK COLLEGE
STATION TO HOUSTON WILL BE THE MAIN AREA OF CONCERN WITH AREAS TO
THE NORTH OF THAT LINE STILL UNDER THE THREAT. COASTAL AREAS HAVE
A LOWER THREAT BUT GIVEN ACCESS TO HIGH MOISTURE AND MESOSCALE
FORCING FROM OUTFLOW BOUNDARIES...NO ONE CAN BE RULED OUT OF THE
HEAVY RAINFALL/FLOOD DISCUSSION. FLOOD WATCH WILL CONTINUE UNTIL
7PM CDT THURSDAY AND DO NOT THINK THERE WILL BE ANY ADJUSTMENTS.
39/38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 84 71 87 71 / 60 80 40 50 20
HOUSTON (IAH) 74 83 71 87 72 / 40 80 40 60 20
GALVESTON (GLS) 79 84 77 85 79 / 40 70 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLOOD WATCH THROUGH THURSDAY EVENING FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
908 PM CDT FRI SEP 19 2014
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 854 PM CDT FRI SEP 19 2014
FORECAST FROM THE DAY SHIFT APPEARS TO BE ON TRACK. TSTMS HAVE
INCREASED OVER THE PAST HOUR IN WEST CENTRAL WI...WHERE STRONG
0-1 KM MOISTURE CONVERGENCE...THE RRQ OF A 90 KT JET STREAK AND
AN INSTABILITY AXIS (MUCAPE 1000-1500 J/KG) ARE ALIGNED. EXPECT
PCPN TO GRADUALLY SHIFT E/SE ACROSS THE FORECAST OVERNIGHT...
AS THE LLJ VEERS WEST AND THE RRQ OF THE UPPER JET PULLS THROUGH.
NOT SURE ABOUT THE COVERAGE OF THE SHRA/TSRA ACTIVITY YET...SO
WILL STICK WITH HIGH CHC POPS FOR NOW. WILL MONITOR OVER THE NEXT
HOUR AND SEE IF POPS NEED TO BE INCREASED.
STILL ANTICIPATE THE POSSIBILITY OF A FEW STRONG STORMS...AS
DEEP LAYER SHEAR IS 40-50+ KTS AND MID-LEVEL LAPSE RATES ARE
STEEP (7-8 C/KM). THE PRESENCE OF A 40-50 KT LLJ WILL ALSO
ENHANCE THE THREAT OF STRONG TSTM WINDS...ALTHOUGH MOST OF
THE INSTABILITY WILL BE ELEVATED.
&&
.SYNOPSIS...
ISSUED AT 243 PM CDT FRI SEP 19 2014
WARM AND A BIT MORE HUMID EARLY IN THE WEEKEND...THEN BRIEFLY
COOLER BEFORE TURNING MILD AND MAINLY DRY NEXT WEEK.
INITIALLY LOW- AMPLITUDE BAND OF WESTERLIES ACRS SRN CANADA AND
THE NRN CONUS WL UNDERGO AMPLIFICATION DURING THE WEEKEND...WITH
UPR RIDGE BUILDING OVER THE INTERMOUNTAIN WEST AND A TROF
DEEPENING THROUGH THE GREAT LAKES RGN. A SLOW PROGRESSION OF THE
LARGE SCALE FEATURES IS EXPECTED...WITH THE POSITIVE ANOMALY ASSOC
WITH THE WRN RIDGE SHIFTG TO THE JAMES BAY REGION BY THE MIDDLE OF
NEXT WEEK...BEFORE THE PROGRESSION SLOWS. THAT WL LEAVE HIGH UPR
HEIGHTS ACRS THE ERN CONUS LATE NEXT WEEK THROUGH THE FOLLOWING
WEEKEND...WITH THE MAIN WESTERLIES WELL TO THE N ACRS CANADA.
TEMPS WL START OUT ABV NORMAL...BRIEFLY DROP TO BLO NORMAL LEVELS
LATE IN THE WEEKEND...THEN WARM BACK TO ABV NORMAL FOR MOST OF
NEXT WEEK. THE MAIN OPPORTUNITY FOR PCPN WL OCCUR EARLY IN THE
FCST PERIOD. UPR RIDGING DOMINATING THE AREA THEREAFTER WL ALLOW
FOR ONLY SCT LGT SHOWERS AT MOST...AND QUITE POSSIBLY TOTALLY DRY
WEATHER FOR THE MIDDLE TO LATTER PART OF THE PERIOD.
&&
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW FLATTENED
MID-LEVEL TROUGHING ACROSS THE NORTHERN PART OF THE COUNTRY FROM
MONTANA TO LAKE SUPERIOR. WITHIN THIS TROUGHING...SEVERAL
SHORTWAVES ARE MOVING TO THE EAST AND ARE CREATING AREAS OF SHOWERS
AND STORMS. ONE AREA IS LOCATED OVER NORTHERN MINNESOTA WHILE
ANOTHER CLUSTER IS OVER FAR NORTHERN LAKE SUPERIOR. A FEW SHOWERS
EXTENDING SOUTHWARD FROM THE LATTER CLUSTER ARE PASSING OVER N-C
WISCONSIN EARLY THIS AFTERNOON. FOR THE REST OF THE AFTERNOON...THE
AREA TO FOCUS ON IS OVER MINNESOTA WHERE PWATS ARE GREATER THAN 1.50
INCHES BUT STILL WAITING FOR INSTABILITY TO ARRIVE. IF THIS AREA
CAN DESTABILIZE LATER THIS AFTERNOON...COULD SEE SOME STRONG STORMS
DEVELOP. THE SURFACE COLD FRONT TRAILS THIS AREA AND REMAINS OVER
THE EASTERN DAKOTAS. AS THE UPSTREAM SHORTWAVES AND COLD FRONT MOVE
THROUGH THE REGION OVER THE NEXT 24 HOURS...PRECIP TIMING AND
THUNDERSTORM POTENTIAL ARE THE MAIN FORECAST CONCERNS.
TONIGHT...PIECES OF SHORTWAVE ENERGY OVER NORTHERN PLAINS WILL MOVE
INTO THE WESTERN GREAT LAKES REGION THIS EVENING. ALONG THE LEADING
EDGE OF THIS ENERGY...MODELS SHOW A RIBBON OF DEEP MOISTURE WITH
PWATS APPROACHING 1.75 INCHES ALONG WITH INCREASING FORCING IN THE
FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL SAG SOUTHEAST
ACROSS THE NORTHWEST HALF OF WISCONSIN THIS EVENING AND NORTHEAST
WISCONSIN OVERNIGHT. VARIOUS MODELS INCLUDING THE RUC/SREF/NAM ALL
DEVELOP MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS LATE THIS
AFTERNOON OR EARLY THIS EVENING OVER WESTERN WISCONSIN COINCIDENT
WITH A RIBBON OF ELEVATED CAPES UPWARDS OF 1000 J/KG. SPC
HIGHLIGHTS THIS AREA FOR A THREAT OF STRONG TO NEAR SEVERE STORMS.
THE FORCING AND RIBBON OF DEEP MOISTURE LOOK TO OUTRUN THIS
INSTABILITY AXIS BY LATE IN THE EVENING AND OVERNIGHT...BUT NOT OUT
OF THE QUESTION THAT A FEW STRONG STORMS (IF THEY DEVELOP) COULD
MAKE IT INTO CENTRAL WISCONSIN BY MID TO LATE EVENING BEFORE
WEAKENING THEREAFTER. WITH THE JET OVERHEAD...STRONG GUSTY WINDS
WOULD BE THE MAIN THREAT FOLLOWED BY SMALL HAIL. COVERAGE OF
SHOWERS AND STORMS SHOULD DIMINISH TO SCATTERED BY THE TIME THEY
REACH NE WISCONSIN OVERNIGHT. BEHIND THE STORMS...A LOW STRATUS
DECK SHOULD SPREAD ACROSS THE AREA...WHICH COULD ALSO CREATE PATCHY
FOG IN SPOTS. A WARM NIGHT WITH LOWS IN THE UPPER 50S TO LOWER 60S.
SATURDAY...A FEW SHOWERS AND ISOLATED STORMS WILL BE EXITING
EAST-CENTRAL WISCONSIN EARLY IN THE MORNING AND MAY ALSO HAVE A FEW
SHOWERS OVER N-C WISCONSIN AS WELL. BUT OTHERWISE...THE DAY SHOULD
START OUT RATHER CLOUDY WITH A LOW OVERCAST DECK IN PLACE. THE LOW
STRATUS WILL LIKELY SLOW THE HEATING CURVE FOR A FEW HOURS IN THE
MORNING...BUT SHOULD LIFT WITH MIXING BY MID TO LATE MORNING. THE
TRAILING SURFACE FRONT WILL BE MOVING ACROSS CENTRAL AND
NORTH-CENTRAL WISCONSIN DURING THIS TIME BUT THE CLOUD COVER SHOULD
KEEP THE FRONT RELATIVELY INACTIVE. AS IT REACHES NORTHEAST AND
EAST-CENTRAL WISCONSIN BY MIDDAY TO EARLY AFTERNOON...POTENTIAL WILL
BE THERE FOR DAYTIME HEATING TO CREATE SURFACE BASED INSTABILITY
OVER THAT PART OF THE STATE. THE NAM GENERATES CLOSE TO 1500 J/KG
OF ML CAPE OVER EAST-CENTRAL WISCONSIN ASSUMING TEMPERATURES CAN
REACH INTO THE MIDDLE 70S. BUT CONVERGENCE ALONG THE FRONT IS
RELATIVELY WEAK AND THERE WILL LIKELY BE A CAP TO OVERCOME. SO
THINK THE POTENTIAL FOR REDEVELOPMENT OF THUNDERSTORMS IS PRETTY LOW
BECAUSE OF THESE FACTORS. HIGHS IN THE UPPER 60S NORTH TO MIDDLE OR
UPPER 70S SOUTH.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
UPR SPEED MAX AND SHARPENING SHRTWV WL DIG SE ACRS THE FCST AREA
SAT NGT AS LARGE SCALE AMPLIFICATION OCCURS. THE STG DYNAMICS WL
BE FAVORABLE FOR PCPN...ESP ACRS THE N. RAISED POPS TO
CATEGORICAL THERE...TAPERING TO A HIGH-END CHC ACRS THE S.
INSTABILITY WON/T BE GREAT...BUT WL PROBABLY BE SUFFICIENT FOR
THUNDER GIVEN THE DYANMICS. TRENDED TOWARD THE HIGH QPFS OF THE
MODELS WITH THE BETTER DEFINED SFC REFLECTION.
BLUSTERY...CLDY...AND MUCH COOLER CONDITIONS ARE LIKELY SUN...
WITH LINGERING SHRA OVER MAINLY THE N/NE/E. TRIMMED MAX
TEMPS...BUT WOULD NOT BE SURPRISED IF THEY END UP EVENTUALLY
NEEDING A BIT MORE PRUNING.
TEMPS SUN NGT TRICKY BECAUSE THEY/LL DEPEND ON CLDS. THINK THERE
WL STILL BE ENOUGH OF A NW FLOW DOWN ACRS LAKE SUPERIOR TO KEEP
THINGS A LITTLE CLOUDIER THAN MUCH OF THE GUIDANCE IS
INDICATING...SO DID NOT TAKE LOWS DOWN TOO FAR. A FROST/FREEZE
WOULD CERTAINLY BE POSSIBLE ACRS MUCH OF THE AREA IF WE TOTALLY
CLEAR OUT.
UPR HEIGHTS REBOUND QUICKLY LATER SUN NGT AND MON...SO THE COOLER
WX WL BE SHORT-LIVED. MODELS HINT THAT WK SHRTWVS WORKING ARND
THE WRN FLANK OF THE UPR RIDGE COULD BRUSH THE AREA AT TIMES.
THAT RESULTED IN SOME LOW-CHC POPS IN THE EXTENDED FCST
INITIALIZATION GRIDS. THAT/S CERTAINLY HARD TO RULE OUT SO LET
THOSE RIDE IN THE FCST. BUT OVERALL...FORCING WL BE WEAK AND
MOISTURE LIMITED...SO EXPECTING A MAINLY DRY PERIOD WITH ABV
NORMAL TEMPS.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 644 PM CDT FRI SEP 19 2014
SOUTH WINDS GUSTING TO 25-30 KTS WILL CONTINUE ACROSS THE REGION
EARLY THIS EVENING. LLWS IS EXPECTED TONIGHT...BUT SHOULD WEAKEN
AT THE WESTERN TAF SITES BY 09Z-10Z...AND AT THE EASTERN TAF
SITES BY 12Z-14Z/SAT.
SHOWERS AND SCT TSTMS ARE EXPECTED TO DEVELOP IN ASSOCIATION WITH
A STRONG LOW-LEVEL JET THIS EVENING...AND MAY CONTINUE LATE TONIGHT
INTO EARLY SATURDAY AS AN UPPER LEVEL JET STREAK MOVES THROUGH.
HAVE NOT INCLUDED THUNDER AT ANY OF THE TAF SITES...AS CONFIDENCE
IN THE TRENDS IS TOO LOW AT THIS TIME. VFR CONDITIONS ARE
EXPECTED BEFORE THE RAIN ARRIVES...BUT MVFR CONDITIONS SHOULD
ACCOMPANY THE FIRST ROUND OF SHOWERS AND STORMS. STRATUS IS EXPECTED
TO DEVELOP OVER NC WI LATE THIS EVG...THEN GRADUALLY WORK ITS WAY
ACROSS THE REST OF THE FORECAST AREA OVERNIGHT INTO EARLY SATURDAY.
IFR CONDITIONS ARE POSSIBLE...ESPECIALLY OVER NC/C WI. EXPECT LOW
CIGS TO GRADUALLY IMPROVE AS A COLD FRONT MOVES THROUGH THE
REGION ON SATURDAY. RIGHT NOW IT DOES NOT APPEAR THAT THERE WILL
BE SIGNIFICANT PCPN ALONG THE FRONT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
658 PM CDT FRI SEP 19 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SYNOPSIS...
ISSUED AT 243 PM CDT FRI SEP 19 2014
WARM AND A BIT MORE HUMID EARLY IN THE WEEKEND...THEN BRIEFLY
COOLER BEFORE TURNING MILD AND MAINLY DRY NEXT WEEK.
INITIALLY LOW- AMPLITUDE BAND OF WESTERLIES ACRS SRN CANADA AND
THE NRN CONUS WL UNDERGO AMPLIFICATION DURING THE WEEKEND...WITH
UPR RIDGE BUILDING OVER THE INTERMOUNTAIN WEST AND A TROF
DEEPENING THROUGH THE GREAT LAKES RGN. A SLOW PROGRESSION OF THE
LARGE SCALE FEATURES IS EXPECTED...WITH THE POSITIVE ANOMALY ASSOC
WITH THE WRN RIDGE SHIFTG TO THE JAMES BAY REGION BY THE MIDDLE OF
NEXT WEEK...BEFORE THE PROGRESSION SLOWS. THAT WL LEAVE HIGH UPR
HEIGHTS ACRS THE ERN CONUS LATE NEXT WEEK THROUGH THE FOLLOWING
WEEKEND...WITH THE MAIN WESTERLIES WELL TO THE N ACRS CANADA.
TEMPS WL START OUT ABV NORMAL...BRIEFLY DROP TO BLO NORMAL LEVELS
LATE IN THE WEEKEND...THEN WARM BACK TO ABV NORMAL FOR MOST OF
NEXT WEEK. THE MAIN OPPORTUNITY FOR PCPN WL OCCUR EARLY IN THE
FCST PERIOD. UPR RIDGING DOMINATING THE AREA THEREAFTER WL ALLOW
FOR ONLY SCT LGT SHOWERS AT MOST...AND QUITE POSSIBLY TOTALLY DRY
WEATHER FOR THE MIDDLE TO LATTER PART OF THE PERIOD.
&&
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW FLATTENED
MID-LEVEL TROUGHING ACROSS THE NORTHERN PART OF THE COUNTRY FROM
MONTANA TO LAKE SUPERIOR. WITHIN THIS TROUGHING...SEVERAL
SHORTWAVES ARE MOVING TO THE EAST AND ARE CREATING AREAS OF SHOWERS
AND STORMS. ONE AREA IS LOCATED OVER NORTHERN MINNESOTA WHILE
ANOTHER CLUSTER IS OVER FAR NORTHERN LAKE SUPERIOR. A FEW SHOWERS
EXTENDING SOUTHWARD FROM THE LATTER CLUSTER ARE PASSING OVER N-C
WISCONSIN EARLY THIS AFTERNOON. FOR THE REST OF THE AFTERNOON...THE
AREA TO FOCUS ON IS OVER MINNESOTA WHERE PWATS ARE GREATER THAN 1.50
INCHES BUT STILL WAITING FOR INSTABILITY TO ARRIVE. IF THIS AREA
CAN DESTABILIZE LATER THIS AFTERNOON...COULD SEE SOME STRONG STORMS
DEVELOP. THE SURFACE COLD FRONT TRAILS THIS AREA AND REMAINS OVER
THE EASTERN DAKOTAS. AS THE UPSTREAM SHORTWAVES AND COLD FRONT MOVE
THROUGH THE REGION OVER THE NEXT 24 HOURS...PRECIP TIMING AND
THUNDERSTORM POTENTIAL ARE THE MAIN FORECAST CONCERNS.
TONIGHT...PIECES OF SHORTWAVE ENERGY OVER NORTHERN PLAINS WILL MOVE
INTO THE WESTERN GREAT LAKES REGION THIS EVENING. ALONG THE LEADING
EDGE OF THIS ENERGY...MODELS SHOW A RIBBON OF DEEP MOISTURE WITH
PWATS APPROACHING 1.75 INCHES ALONG WITH INCREASING FORCING IN THE
FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL SAG SOUTHEAST
ACROSS THE NORTHWEST HALF OF WISCONSIN THIS EVENING AND NORTHEAST
WISCONSIN OVERNIGHT. VARIOUS MODELS INCLUDING THE RUC/SREF/NAM ALL
DEVELOP MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS LATE THIS
AFTERNOON OR EARLY THIS EVENING OVER WESTERN WISCONSIN COINCIDENT
WITH A RIBBON OF ELEVATED CAPES UPWARDS OF 1000 J/KG. SPC
HIGHLIGHTS THIS AREA FOR A THREAT OF STRONG TO NEAR SEVERE STORMS.
THE FORCING AND RIBBON OF DEEP MOISTURE LOOK TO OUTRUN THIS
INSTABILITY AXIS BY LATE IN THE EVENING AND OVERNIGHT...BUT NOT OUT
OF THE QUESTION THAT A FEW STRONG STORMS (IF THEY DEVELOP) COULD
MAKE IT INTO CENTRAL WISCONSIN BY MID TO LATE EVENING BEFORE
WEAKENING THEREAFTER. WITH THE JET OVERHEAD...STRONG GUSTY WINDS
WOULD BE THE MAIN THREAT FOLLOWED BY SMALL HAIL. COVERAGE OF
SHOWERS AND STORMS SHOULD DIMINISH TO SCATTERED BY THE TIME THEY
REACH NE WISCONSIN OVERNIGHT. BEHIND THE STORMS...A LOW STRATUS
DECK SHOULD SPREAD ACROSS THE AREA...WHICH COULD ALSO CREATE PATCHY
FOG IN SPOTS. A WARM NIGHT WITH LOWS IN THE UPPER 50S TO LOWER 60S.
SATURDAY...A FEW SHOWERS AND ISOLATED STORMS WILL BE EXITING
EAST-CENTRAL WISCONSIN EARLY IN THE MORNING AND MAY ALSO HAVE A FEW
SHOWERS OVER N-C WISCONSIN AS WELL. BUT OTHERWISE...THE DAY SHOULD
START OUT RATHER CLOUDY WITH A LOW OVERCAST DECK IN PLACE. THE LOW
STRATUS WILL LIKELY SLOW THE HEATING CURVE FOR A FEW HOURS IN THE
MORNING...BUT SHOULD LIFT WITH MIXING BY MID TO LATE MORNING. THE
TRAILING SURFACE FRONT WILL BE MOVING ACROSS CENTRAL AND
NORTH-CENTRAL WISCONSIN DURING THIS TIME BUT THE CLOUD COVER SHOULD
KEEP THE FRONT RELATIVELY INACTIVE. AS IT REACHES NORTHEAST AND
EAST-CENTRAL WISCONSIN BY MIDDAY TO EARLY AFTERNOON...POTENTIAL WILL
BE THERE FOR DAYTIME HEATING TO CREATE SURFACE BASED INSTABILITY
OVER THAT PART OF THE STATE. THE NAM GENERATES CLOSE TO 1500 J/KG
OF ML CAPE OVER EAST-CENTRAL WISCONSIN ASSUMING TEMPERATURES CAN
REACH INTO THE MIDDLE 70S. BUT CONVERGENCE ALONG THE FRONT IS
RELATIVELY WEAK AND THERE WILL LIKELY BE A CAP TO OVERCOME. SO
THINK THE POTENTIAL FOR REDEVELOPMENT OF THUNDERSTORMS IS PRETTY LOW
BECAUSE OF THESE FACTORS. HIGHS IN THE UPPER 60S NORTH TO MIDDLE OR
UPPER 70S SOUTH.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
UPR SPEED MAX AND SHARPENING SHRTWV WL DIG SE ACRS THE FCST AREA
SAT NGT AS LARGE SCALE AMPLIFICATION OCCURS. THE STG DYNAMICS WL
BE FAVORABLE FOR PCPN...ESP ACRS THE N. RAISED POPS TO
CATEGORICAL THERE...TAPERING TO A HIGH-END CHC ACRS THE S.
INSTABILITY WON/T BE GREAT...BUT WL PROBABLY BE SUFFICIENT FOR
THUNDER GIVEN THE DYANMICS. TRENDED TOWARD THE HIGH QPFS OF THE
MODELS WITH THE BETTER DEFINED SFC REFLECTION.
BLUSTERY...CLDY...AND MUCH COOLER CONDITIONS ARE LIKELY SUN...
WITH LINGERING SHRA OVER MAINLY THE N/NE/E. TRIMMED MAX
TEMPS...BUT WOULD NOT BE SURPRISED IF THEY END UP EVENTUALLY
NEEDING A BIT MORE PRUNING.
TEMPS SUN NGT TRICKY BECAUSE THEY/LL DEPEND ON CLDS. THINK THERE
WL STILL BE ENOUGH OF A NW FLOW DOWN ACRS LAKE SUPERIOR TO KEEP
THINGS A LITTLE CLOUDIER THAN MUCH OF THE GUIDANCE IS
INDICATING...SO DID NOT TAKE LOWS DOWN TOO FAR. A FROST/FREEZE
WOULD CERTAINLY BE POSSIBLE ACRS MUCH OF THE AREA IF WE TOTALLY
CLEAR OUT.
UPR HEIGHTS REBOUND QUICKLY LATER SUN NGT AND MON...SO THE COOLER
WX WL BE SHORT-LIVED. MODELS HINT THAT WK SHRTWVS WORKING ARND
THE WRN FLANK OF THE UPR RIDGE COULD BRUSH THE AREA AT TIMES.
THAT RESULTED IN SOME LOW-CHC POPS IN THE EXTENDED FCST
INITIALIZATION GRIDS. THAT/S CERTAINLY HARD TO RULE OUT SO LET
THOSE RIDE IN THE FCST. BUT OVERALL...FORCING WL BE WEAK AND
MOISTURE LIMITED...SO EXPECTING A MAINLY DRY PERIOD WITH ABV
NORMAL TEMPS.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 644 PM CDT FRI SEP 19 2014
SOUTH WINDS GUSTING TO 25-30 KTS WILL CONTINUE ACROSS THE REGION
EARLY THIS EVENING. LLWS IS EXPECTED TONIGHT...BUT SHOULD WEAKEN
AT THE WESTERN TAF SITES BY 09Z-10Z...AND AT THE EASTERN TAF
SITES BY 12Z-14Z/SAT.
SHOWERS AND SCT TSTMS ARE EXPECTED TO DEVELOP IN ASSOCIATION WITH
A STRONG LOW-LEVEL JET THIS EVENING...AND MAY CONTINUE LATE TONIGHT
INTO EARLY SATURDAY AS AN UPPER LEVEL JET STREAK MOVES THROUGH.
HAVE NOT INCLUDED THUNDER AT ANY OF THE TAF SITES...AS CONFIDENCE
IN THE TRENDS IS TOO LOW AT THIS TIME. VFR CONDITIONS ARE
EXPECTED BEFORE THE RAIN ARRIVES...BUT MVFR CONDITIONS SHOULD
ACCOMPANY THE FIRST ROUND OF SHOWERS AND STORMS. STRATUS IS EXPECTED
TO DEVELOP OVER NC WI LATE THIS EVG...THEN GRADUALLY WORK ITS WAY
ACROSS THE REST OF THE FORECAST AREA OVERNIGHT INTO EARLY SATURDAY.
IFR CONDITIONS ARE POSSIBLE...ESPECIALLY OVER NC/C WI. EXPECT LOW
CIGS TO GRADUALLY IMPROVE AS A COLD FRONT MOVES THROUGH THE
REGION ON SATURDAY. RIGHT NOW IT DOES NOT APPEAR THAT THERE WILL
BE SIGNIFICANT PCPN ALONG THE FRONT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
620 PM CDT FRI SEP 19 2014
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 222 PM CDT FRI SEP 19 2014
CONCERN FOCUSED ON CONVECTION/SEVERE POTENTIAL TONIGHT.
WATER VAPOR/RAP 500MB ANALYSIS SHOWING A FAIRLY VIGOROUS MID-LEVEL
TROUGH MOVING EAST ACROSS THE DAKOTAS. AT THE SURFACE...LOW PRESSURE
WAS LOCATED OVER SOUTHERN MANITOBA CANADA WITH A TRAILING TROUGH
THROUGH THE EASTERN DAKOTAS INTO CENTRAL NEB. RADAR MOSAIC SHOWING
SCATTERED SHOWERS/ISOLATED THUNDER ACROSS PORTIONS OF ND INTO
NORTHERN MN IN RESPONSE TO CORRIDOR OF 850MB MOISTURE TRANSPORT/310K
ISENTROPIC LIFT AHEAD OF THE APPROACHING TROUGH. OTHERWISE...BREEZY
SOUTH WINDS IN PLACE ACROSS THE FORECAST AREA THIS AFTERNOON WITH
MOSTLY SUNNY SKIES. TEMPERATURES WERE IN THE UPPER 60S TO THE MIDDLE
70S.
FOR TONIGHT...LOOK FOR THAT MID-LEVEL/SURFACE TROUGH TO ROTATE
SOUTHEAST ACROSS THE AREA TONIGHT. MODELS OFFERING UP VARIOUS
SOLUTIONS ON CONVECTIVE SCHEMES BASED ON FAIRLY STRONG CAP IN PLACE.
THINKING WITH INCREASING 850MB MOISTURE TRANSPORT/EVENTUAL
STEEPENING OF MID-LEVEL LAPSE RATES AND LIFT WITH THE TROUGH
PASSAGE...THIS WILL BE ENOUGH FORCING TO SEE AT LEAST A SCATTERED
BAND OF THUNDERSTORMS. THINKING THIS CONVECTION WILL INITIALLY START
OUT ELEVATED IN NATURE ABOVE THE CAP...BUT THEN CAP WEAKENS LATE
THIS EVENING INTO THE OVERNIGHT HOURS ALLOWING FOR AN UPTICK IN
THUNDERSTORM COVERAGE. STILL THINKING THERE IS A MARGINAL SEVERE
THREAT. MODEL CONSENSUS SHOWING 0-3KM MUCAPE VALUES OF 1000-200J/KG
ALONG WITH EFFECTIVE BULK SHEAR AROUND 30KT. THIS COULD PRODUCE A
FEW VIGOROUS/ROTATING UPDRAFTS CAPABLE OF LARGER HAIL PRODUCTION
AND DAMAGING WIND POTENTIAL.
LINGERING SHOWERS/THUNDERSTORMS WILL BE POSSIBLE ACROSS SOUTHERN WI
INTO NORTHEAST IA ON SATURDAY AS THE TROUGH CONTINUES TO ROTATE
SOUTHEAST OUT OF THE AREA. FOR LATER SATURDAY AFTERNOON INTO
SATURDAY EVENING...MODELS SHOWING A FAIRLY COMPACT/VIGOROUS PV-
ANOMALY ROTATING SOUTHEAST OUT OF THE NORTHERN PLAINS IN OUR AREA.
THE BULK OF THE FORCING WITH THIS FEATURE SEEMS TO BE FOCUSED ALONG
AND NORTHEAST OF I-94. AS SUCH...WENT WITH THE LIKELIHOOD OF
SHOWERS/ISOLATED THUNDER NORTHEAST OF I-94 AND TAPERED TO LOWER-END
CHANCES ACROSS NORTHEAST IA/FAR SOUTHWEST WI. WITH THE WARMER START
TO SATURDAY...LOOK FOR HIGHS TO PERK UP INTO THE 70S TO A FEW LOWER
80S ALONG AND SOUTH OF I-90. LOOK FOR THE SHOWERS AND ISOLATED
STORMS TO TAPER OFF/MOVE EAST OF THE AREA BY MIDNIGHT SATURDAY
NIGHT WITH OVERNIGHT LOWS DIPPING INTO THE 50S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 222 PM CDT FRI SEP 19 2014
COOLER CYCLONIC FLOW ALOFT ON SUNDAY WILL PRODUCE COOLER
TEMPERATURES IN THE 60S ALONG WITH BREEZY NORTHWEST WINDS. ALSO
LOOKS LIKE THERE WILL ALSO BE ENOUGH INSTABILITY NORTHEAST OF I-94
TO PRODUCE A FEW SHOWERS.
HIGH PRESSURE BUILDS OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION
SUNDAY NIGHT. CLEAR SKIES AND LIGHT/CALM WINDS WILL SET UP IDEAL
RADIATIONAL COOLING FOR AREAS OF FOG...ESPECIALLY FAVORED RIVER
VALLEY LOCATIONS AND THE SANDY/BOG COUNTRY OF CENTRAL WI. PLAN ON
LOWS IN THE LOWER 40S OVER CENTRAL WI...AND IN THE MIDDLE/UPPER 40S
ELSEWHERE ACROSS THE FORECAST AREA.
AFTER A COOL/POTENTIALLY FOGGY START...HIGH PRESSURE LOOKS TO
PROVIDE A DRY/QUIET/MOSTLY SUNNY MONDAY WITH HIGHS MIDDLE 60S TO
NEAR 70.
FOR TUESDAY THROUGH FRIDAY...A RIDGE OF HIGH PRESSURE TRIES TO
ESTABLISH ITSELF OVER THE CENTRAL CONUS. HOWEVER...MODELS SHOWING A
TROUGH EJECTING OUT OF THE INTERMOUNTAIN WEST INTO THE UPPER
MISSISSIPPI RIVER VALLEY BY WEDNESDAY INTO THURSDAY. BELIEVE THIS
MAY BE A BIT OVER DONE...BUT WILL GO WITH MODEL CONSENSUS AT THIS
POINT AND INCLUDE SMALL-END SHOWER/THUNDER CHANCES IN THE TUESDAY
NIGHT THROUGH THURSDAY PERIOD. AS THE TROUGH MOVES OFF TO THE
EAST...THE RIDGE RE-ESTABLISHES ITSELF ON FRIDAY FOR DRIER/WARMER
CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 620 PM CDT FRI SEP 19 2014
STILL SOME UNCERTAINTY ON WHERE AND IF CONVECTION WILL DEVELOP
ACROSS THE AREA THIS EVENING. THE MAJORITY OF THE MESO SCALE
MODELS ARE NOW FOCUSING ON NORTHWEST IOWA AS THE INITIATION POINT
AHEAD OF THE INCOMING SHORT WAVE TROUGH FROM THE DAKOTAS...UNDER
THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET AND ALONG THE
NORTHERN EDGE OF THE MID LEVEL CAP. THE DIFFERENCES IN THE MODELS
ARE WITH HOW MUCH CONVECTION THEN FILLS IN TO THE NORTHEAST ALONG
THE FRONT. THE 19.20Z HRRR WANTS TO SHOW SOME SCATTERED ACTIVITY
POSSIBLY IMPACTING BOTH TAF SITES WHILE THE 19.12Z HI-RES ARW
WOULD SUGGEST THE ACTIVITY WOULD NOT FILL IN ALONG THE FRONT UNTIL
IT WAS PAST THE TAF SITES. THE 19.18Z NAM IS SIMILAR TO THE HI-RES
ARW WHILE THE 19.18Z CR-NAMNEST IS CLOSER TO THE HRRR. SO FOR
NOW...UNTIL IT BECOMES CLEARER WHAT IS GOING TO TRANSPIRE...WILL
STAY WITH THE PREVIOUS TRENDS OF SHOWING A VCTS AT BOTH SITES THIS
EVENING INTO THE EARLY OVERNIGHT HOURS. AFTER THAT...EXPECT VFR
CONDITIONS THROUGH SATURDAY WITH THE WINDS COMING AROUND TO THE
NORTHWEST WITH THE PASSAGE OF THE COLD FRONT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 243 PM CDT FRI SEP 19 2014
WARM AND A BIT MORE HUMID EARLY IN THE WEEKEND...THEN BRIEFLY
COOLER BEFORE TURNING MILD AND MAINLY DRY NEXT WEEK.
INITIALLY LOW- AMPLITUDE BAND OF WESTERLIES ACRS SRN CANADA AND
THE NRN CONUS WL UNDERGO AMPLIFICATION DURING THE WEEKEND...WITH
UPR RIDGE BUILDING OVER THE INTERMOUNTAIN WEST AND A TROF
DEEPENING THROUGH THE GREAT LAKES RGN. A SLOW PROGRESSION OF THE
LARGE SCALE FEATURES IS EXPECTED...WITH THE POSITIVE ANOMALY ASSOC
WITH THE WRN RIDGE SHIFTG TO THE JAMES BAY REGION BY THE MIDDLE OF
NEXT WEEK...BEFORE THE PROGRESSION SLOWS. THAT WL LEAVE HIGH UPR
HEIGHTS ACRS THE ERN CONUS LATE NEXT WEEK THROUGH THE FOLLOWING
WEEKEND...WITH THE MAIN WESTERLIES WELL TO THE N ACRS CANADA.
TEMPS WL START OUT ABV NORMAL...BRIEFLY DROP TO BLO NORMAL LEVELS
LATE IN THE WEEKEND...THEN WARM BACK TO ABV NORMAL FOR MOST OF
NEXT WEEK. THE MAIN OPPORTUNITY FOR PCPN WL OCCUR EARLY IN THE
FCST PERIOD. UPR RIDGING DOMINATING THE AREA THEREAFTER WL ALLOW
FOR ONLY SCT LGT SHOWERS AT MOST...AND QUITE POSSIBLY TOTALLY DRY
WEATHER FOR THE MIDDLE TO LATTER PART OF THE PERIOD.
&&
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW FLATTENED
MID-LEVEL TROUGHING ACROSS THE NORTHERN PART OF THE COUNTRY FROM
MONTANA TO LAKE SUPERIOR. WITHIN THIS TROUGHING...SEVERAL
SHORTWAVES ARE MOVING TO THE EAST AND ARE CREATING AREAS OF SHOWERS
AND STORMS. ONE AREA IS LOCATED OVER NORTHERN MINNESOTA WHILE
ANOTHER CLUSTER IS OVER FAR NORTHERN LAKE SUPERIOR. A FEW SHOWERS
EXTENDING SOUTHWARD FROM THE LATTER CLUSTER ARE PASSING OVER N-C
WISCONSIN EARLY THIS AFTERNOON. FOR THE REST OF THE AFTERNOON...THE
AREA TO FOCUS ON IS OVER MINNESOTA WHERE PWATS ARE GREATER THAN 1.50
INCHES BUT STILL WAITING FOR INSTABILITY TO ARRIVE. IF THIS AREA
CAN DESTABILIZE LATER THIS AFTERNOON...COULD SEE SOME STRONG STORMS
DEVELOP. THE SURFACE COLD FRONT TRAILS THIS AREA AND REMAINS OVER
THE EASTERN DAKOTAS. AS THE UPSTREAM SHORTWAVES AND COLD FRONT MOVE
THROUGH THE REGION OVER THE NEXT 24 HOURS...PRECIP TIMING AND
THUNDERSTORM POTENTIAL ARE THE MAIN FORECAST CONCERNS.
TONIGHT...PIECES OF SHORTWAVE ENERGY OVER NORTHERN PLAINS WILL MOVE
INTO THE WESTERN GREAT LAKES REGION THIS EVENING. ALONG THE LEADING
EDGE OF THIS ENERGY...MODELS SHOW A RIBBON OF DEEP MOISTURE WITH
PWATS APPROACHING 1.75 INCHES ALONG WITH INCREASING FORCING IN THE
FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL SAG SOUTHEAST
ACROSS THE NORTHWEST HALF OF WISCONSIN THIS EVENING AND NORTHEAST
WISCONSIN OVERNIGHT. VARIOUS MODELS INCLUDING THE RUC/SREF/NAM ALL
DEVELOP MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS LATE THIS
AFTERNOON OR EARLY THIS EVENING OVER WESTERN WISCONSIN COINCIDENT
WITH A RIBBON OF ELEVATED CAPES UPWARDS OF 1000 J/KG. SPC
HIGHLIGHTS THIS AREA FOR A THREAT OF STRONG TO NEAR SEVERE STORMS.
THE FORCING AND RIBBON OF DEEP MOISTURE LOOK TO OUTRUN THIS
INSTABILITY AXIS BY LATE IN THE EVENING AND OVERNIGHT...BUT NOT OUT
OF THE QUESTION THAT A FEW STRONG STORMS (IF THEY DEVELOP) COULD
MAKE IT INTO CENTRAL WISCONSIN BY MID TO LATE EVENING BEFORE
WEAKENING THEREAFTER. WITH THE JET OVERHEAD...STRONG GUSTY WINDS
WOULD BE THE MAIN THREAT FOLLOWED BY SMALL HAIL. COVERAGE OF
SHOWERS AND STORMS SHOULD DIMINISH TO SCATTERED BY THE TIME THEY
REACH NE WISCONSIN OVERNIGHT. BEHIND THE STORMS...A LOW STRATUS
DECK SHOULD SPREAD ACROSS THE AREA...WHICH COULD ALSO CREATE PATCHY
FOG IN SPOTS. A WARM NIGHT WITH LOWS IN THE UPPER 50S TO LOWER 60S.
SATURDAY...A FEW SHOWERS AND ISOLATED STORMS WILL BE EXITING
EAST-CENTRAL WISCONSIN EARLY IN THE MORNING AND MAY ALSO HAVE A FEW
SHOWERS OVER N-C WISCONSIN AS WELL. BUT OTHERWISE...THE DAY SHOULD
START OUT RATHER CLOUDY WITH A LOW OVERCAST DECK IN PLACE. THE LOW
STRATUS WILL LIKELY SLOW THE HEATING CURVE FOR A FEW HOURS IN THE
MORNING...BUT SHOULD LIFT WITH MIXING BY MID TO LATE MORNING. THE
TRAILING SURFACE FRONT WILL BE MOVING ACROSS CENTRAL AND
NORTH-CENTRAL WISCONSIN DURING THIS TIME BUT THE CLOUD COVER SHOULD
KEEP THE FRONT RELATIVELY INACTIVE. AS IT REACHES NORTHEAST AND
EAST-CENTRAL WISCONSIN BY MIDDAY TO EARLY AFTERNOON...POTENTIAL WILL
BE THERE FOR DAYTIME HEATING TO CREATE SURFACE BASED INSTABILITY
OVER THAT PART OF THE STATE. THE NAM GENERATES CLOSE TO 1500 J/KG
OF ML CAPE OVER EAST-CENTRAL WISCONSIN ASSUMING TEMPERATURES CAN
REACH INTO THE MIDDLE 70S. BUT CONVERGENCE ALONG THE FRONT IS
RELATIVELY WEAK AND THERE WILL LIKELY BE A CAP TO OVERCOME. SO
THINK THE POTENTIAL FOR REDEVELOPMENT OF THUNDERSTORMS IS PRETTY LOW
BECAUSE OF THESE FACTORS. HIGHS IN THE UPPER 60S NORTH TO MIDDLE OR
UPPER 70S SOUTH.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
UPR SPEED MAX AND SHARPENING SHRTWV WL DIG SE ACRS THE FCST AREA
SAT NGT AS LARGE SCALE AMPLIFICATION OCCURS. THE STG DYNAMICS WL
BE FAVORABLE FOR PCPN...ESP ACRS THE N. RAISED POPS TO
CATEGORICAL THERE...TAPERING TO A HIGH-END CHC ACRS THE S.
INSTABILITY WON/T BE GREAT...BUT WL PROBABLY BE SUFFICIENT FOR
THUNDER GIVEN THE DYANMICS. TRENDED TOWARD THE HIGH QPFS OF THE
MODELS WITH THE BETTER DEFINED SFC REFLECTION.
BLUSTERY...CLDY...AND MUCH COOLER CONDITIONS ARE LIKELY SUN...
WITH LINGERING SHRA OVER MAINLY THE N/NE/E. TRIMMED MAX
TEMPS...BUT WOULD NOT BE SURPRISED IF THEY END UP EVENTUALLY
NEEDING A BIT MORE PRUNING.
TEMPS SUN NGT TRICKY BECAUSE THEY/LL DEPEND ON CLDS. THINK THERE
WL STILL BE ENOUGH OF A NW FLOW DOWN ACRS LAKE SUPERIOR TO KEEP
THINGS A LITTLE CLOUDIER THAN MUCH OF THE GUIDANCE IS
INDICATING...SO DID NOT TAKE LOWS DOWN TOO FAR. A FROST/FREEZE
WOULD CERTAINLY BE POSSIBLE ACRS MUCH OF THE AREA IF WE TOTALLY
CLEAR OUT.
UPR HEIGHTS REBOUND QUICKLY LATER SUN NGT AND MON...SO THE COOLER
WX WL BE SHORT-LIVED. MODELS HINT THAT WK SHRTWVS WORKING ARND
THE WRN FLANK OF THE UPR RIDGE COULD BRUSH THE AREA AT TIMES.
THAT RESULTED IN SOME LOW-CHC POPS IN THE EXTENDED FCST
INITIALIZATION GRIDS. THAT/S CERTAINLY HARD TO RULE OUT SO LET
THOSE RIDE IN THE FCST. BUT OVERALL...FORCING WL BE WEAK AND
MOISTURE LIMITED...SO EXPECTING A MAINLY DRY PERIOD WITH ABV
NORMAL TEMPS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1140 AM CDT FRI SEP 19 2014
GUSTY SOUTHWEST WINDS UP TO 25 OR 30 KTS WILL CONTINUE
UNTIL EARLY THIS EVENING ACROSS THE REGION BUT WITH VFR CONDITIONS. THEN
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A COLD FRONT
OVER MINNESOTA AND IOWA LATE THIS AFTERNOON OR THIS EVENING. SOME
OF THESE STORMS WILL MAKE A RUN TOWARDS THE CENTRAL WISCONSIN TAF
SITES AND POSSIBLY NORTH-CENTRAL WISCONSIN AS WELL. GUSTY WINDS AND
SMALL HAIL ARE POSSIBLE WITHIN ANY STORMS. THESE STORMS ARE EXPECT
TO WEAKEN LATE TONIGHT AS THEY APPROACH THE FOX VALLEY AND LAKE
SHORE TAF SITES. BEHIND THE STORMS...CIGS/VSBYS WILL BE DROPPING
QUICKLY TO IFR AND MVFR LEVELS. IMPROVEMENT TO THE CIGS AND VSBYS
WILL TAKE PLACE BY MID TO LATE MORNING ON SATURDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1236 PM CDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERNS TODAY ARE CLOUD TRENDS.
LATEST 08Z SURFACE ANALYSIS SHOWS WEAK COLD FRONT EXTENDING FROM
EASTERN WISCONSIN INTO WESTERN MINNESOTA. LATEST FOG PRODUCT
SATELLITE IMAGERY INDICATES LOW LEVEL STRATUS OVER PORTIONS OF
NORTHERN AND EASTERN HALF OF WISCONSIN AND EAST CENTRAL
MINNESOTA. THIS LOW LEVEL STRATUS IS MOVING SOUTH AND WEST BEHIND
THE WEAK SURFACE FRONT.
THE 18.00Z GFS/NAM AND 18.06Z RAP APPEAR INITIALIZE AND HANDLE
MOVEMENT/EXPANSION OF LOW LEVEL STRATUS WELL INTO WESTERN WISCONSIN
EARLY THIS MORNING/TODAY PER THE 925MB RELATIVE HUMIDITY FIELDS. THE
BIG QUESTION WILL BE HOW LONG WILL THE LOW LEVEL STRATUS HANGS
AROUND THE FORECAST AREA TODAY. THE 18.00Z GFS/NAM AND 18.06Z RAP
SUGGEST THE CLOUDS WILL ERODE DUE TO DAYTIME HEATING AND LIFT BACK
NORTH INTO NORTHERN WISCONSIN AROUND 18Z TODAY. IF LOW LEVEL STRATUS
ERODES LATER IN THE AFTERNOON...THIS WILL HAVE IMPACTS ON FORECAST
HIGH TEMPERATURES FOR TODAY...ESPECIALLY OVER EASTERN PART OF THE
FORECAST AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY INTO SATURDAY
NIGHT. THE LATEST 18.00Z GFS/NAM/ECMWF SHOW DECENT ISENTROPIC LIFT
AT 305K SURFACE BETWEEN 12-18Z FRIDAY AND ASSOCIATED 925-850MB
MOISTURE TRANSPORT INTO THE WESTERN FORECAST AREA. THE COMBINATION
OF ELEVATED INSTABILITY OF 0-6KM MOST UNSTABLE CAPE OF 300-800
J/KG OVER THE WESTERN FORECAST AREA AND THIS LIFT...WARRANTS A
SMALL PRECIPITATION CHANCE OVER THE WESTERN FORECAST AREA BETWEEN
12-18Z FRIDAY.
AFTER THIS INITIAL WEAK IMPULSE IN ASSOCIATION WITH WARM AIR
ADVECTION...THE 18.0ZZ GFS/NAM/ECMWF INDICATE MUCH OF THE
SOUTHERN FORECAST AREA BECOMES CAPPED AFTER 18Z FRIDAY...AS
SHORTWAVE RIDGE BUILDS INTO THE AREA AND FOCUSES LIFT/MOISTURE
TRANSPORT INTO NORTHERN WISCONSIN. HAVE ADJUSTED PRECIPITATION
CHANCES FURTHER NORTH AFTER 18Z FRIDAY. THE CAP BEGINS TO WEAKEN
AFTER 00Z SATURDAY ACROSS THE FORECAST AREA...IN ADDITION SURFACE
FRONT PUSHES ACROSS FORECAST AREA AND DEEP FORCING/MOISTURE
TRANSPORT/CONVERGENCE WILL ALLOW SHOWERS AND THUNDERSTORMS TO
DEVELOP IN THE 00-06Z SATURDAY TIMEFRAME AND MOVE NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT. ANY SEVERE THREAT
WITH THE THUNDERSTORMS LOOKS TO BE CONFINED NORTH OF THE
INTERSTATE 90 CORRIDOR...WHERE THE BETTER INSTABILITY AND SHEAR
WILL BE OVER THE FORECAST AREA. AT THIS TIME...THE SEVERE THREAT
LOOKS TO BE ISOLATED AND THE MAIN THREATS WOULD BE LARGE HAIL AND
DAMAGING WINDS.
SURFACE FRONT/SHORTWAVE TROUGH PUSHES SOUTH AND EAST OF FORECAST
AREA SATURDAY AND TAKING THE BULK OF LIFT AND BETTER INSTABILITY
SOUTH AND EAST OF FORECAST AREA. THE REGION WILL BE UNDER THE
INFLUENCE OF CYCLONIC FLOW SATURDAY...WITH STEEPENING LAPSE RATES
AND A COUPLE HUNDRED ELEVATED CAPE PER BUFKIT SOUNDINGS. SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ACROSS THE FORECAST
AREA. HAVE LEFT SMALL PRECIPITATION CHANCES IN THE FORECAST.
UPPER LEVEL TROUGH BEGINS TO BREAK DOWN OVER THE GREAT LAKES
REGION AND HEIGHTS RISE OVER THE NORTHERN PLAINS LATE SUNDAY INTO
THE MIDDLE OF NEXT WEEK. THE 18.00Z GFS/ECMWF ARE INDICATING
UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES BY 00Z
THURSDAY. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL EARLY TO
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM CDT THU SEP 18 2014
AN IFR/MVFR STRATUS FIELD HAS SLOWLY LIFTED TO THE NORTHEAST IN
WESTERN WISCONSIN WITH LSE NOW INTO VFR CONDITIONS. SOME VFR CU
WILL FORM THIS AFTERNOON BEFORE SKIES CLEAR OUT TONIGHT. WINDS
WILL BE ON THE INCREASE OVERNIGHT AS A RIDGE OF HIGH PRESSURE
SHIFTS TO THE EAST AND THE PRESSURE GRADIENT TIGHTENS UP ACROSS
THE REGION. THIS SHOULD HELP TO KEEP ANY FOG FROM FORMING
OVERNIGHT...BUT WILL HAVE TO WATCH FOR ANY POSSIBLE LOW STRATUS
THAT COULD FORM UNDER THE INVERSION. RIGHT NOW...IT APPEARS THAT
THE BETTER CHANCES FOR THIS STRATUS WILL BE IN NORTHERN WISCONSIN
AND FURTHER TO THE WEST...SO WILL KEEP SKIES CLEAR OVERNIGHT.
WINDS WILL PICK UP QUICKLY IN THE MORNING WITH SOME GUSTS IN THE
20-30KT RANGE EXPECTED OUT OF THE SOUTH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
643 AM CDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERNS TODAY ARE CLOUD TRENDS.
LATEST 08Z SURFACE ANALYSIS SHOWS WEAK COLD FRONT EXTENDING FROM
EASTERN WISCONSIN INTO WESTERN MINNESOTA. LATEST FOG PRODUCT
SATELLITE IMAGERY INDICATES LOW LEVEL STRATUS OVER PORTIONS OF
NORTHERN AND EASTERN HALF OF WISCONSIN AND EAST CENTRAL
MINNESOTA. THIS LOW LEVEL STRATUS IS MOVING SOUTH AND WEST BEHIND
THE WEAK SURFACE FRONT.
THE 18.00Z GFS/NAM AND 18.06Z RAP APPEAR INITIALIZE AND HANDLE
MOVEMENT/EXPANSION OF LOW LEVEL STRATUS WELL INTO WESTERN WISCONSIN
EARLY THIS MORNING/TODAY PER THE 925MB RELATIVE HUMIDITY FIELDS. THE
BIG QUESTION WILL BE HOW LONG WILL THE LOW LEVEL STRATUS HANGS
AROUND THE FORECAST AREA TODAY. THE 18.00Z GFS/NAM AND 18.06Z RAP
SUGGEST THE CLOUDS WILL ERODE DUE TO DAYTIME HEATING AND LIFT BACK
NORTH INTO NORTHERN WISCONSIN AROUND 18Z TODAY. IF LOW LEVEL STRATUS
ERODES LATER IN THE AFTERNOON...THIS WILL HAVE IMPACTS ON FORECAST
HIGH TEMPERATURES FOR TODAY...ESPECIALLY OVER EASTERN PART OF THE
FORECAST AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY INTO SATURDAY
NIGHT. THE LATEST 18.00Z GFS/NAM/ECMWF SHOW DECENT ISENTROPIC LIFT
AT 305K SURFACE BETWEEN 12-18Z FRIDAY AND ASSOCIATED 925-850MB
MOISTURE TRANSPORT INTO THE WESTERN FORECAST AREA. THE COMBINATION
OF ELEVATED INSTABILITY OF 0-6KM MOST UNSTABLE CAPE OF 300-800
J/KG OVER THE WESTERN FORECAST AREA AND THIS LIFT...WARRANTS A
SMALL PRECIPITATION CHANCE OVER THE WESTERN FORECAST AREA BETWEEN
12-18Z FRIDAY.
AFTER THIS INITIAL WEAK IMPULSE IN ASSOCIATION WITH WARM AIR
ADVECTION...THE 18.0ZZ GFS/NAM/ECMWF INDICATE MUCH OF THE
SOUTHERN FORECAST AREA BECOMES CAPPED AFTER 18Z FRIDAY...AS
SHORTWAVE RIDGE BUILDS INTO THE AREA AND FOCUSES LIFT/MOISTURE
TRANSPORT INTO NORTHERN WISCONSIN. HAVE ADJUSTED PRECIPITATION
CHANCES FURTHER NORTH AFTER 18Z FRIDAY. THE CAP BEGINS TO WEAKEN
AFTER 00Z SATURDAY ACROSS THE FORECAST AREA...IN ADDITION SURFACE
FRONT PUSHES ACROSS FORECAST AREA AND DEEP FORCING/MOISTURE
TRANSPORT/CONVERGENCE WILL ALLOW SHOWERS AND THUNDERSTORMS TO
DEVELOP IN THE 00-06Z SATURDAY TIMEFRAME AND MOVE NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT. ANY SEVERE THREAT
WITH THE THUNDERSTORMS LOOKS TO BE CONFINED NORTH OF THE
INTERSTATE 90 CORRIDOR...WHERE THE BETTER INSTABILITY AND SHEAR
WILL BE OVER THE FORECAST AREA. AT THIS TIME...THE SEVERE THREAT
LOOKS TO BE ISOLATED AND THE MAIN THREATS WOULD BE LARGE HAIL AND
DAMAGING WINDS.
SURFACE FRONT/SHORTWAVE TROUGH PUSHES SOUTH AND EAST OF FORECAST
AREA SATURDAY AND TAKING THE BULK OF LIFT AND BETTER INSTABILITY
SOUTH AND EAST OF FORECAST AREA. THE REGION WILL BE UNDER THE
INFLUENCE OF CYCLONIC FLOW SATURDAY...WITH STEEPENING LAPSE RATES
AND A COUPLE HUNDRED ELEVATED CAPE PER BUFKIT SOUNDINGS. SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ACROSS THE FORECAST
AREA. HAVE LEFT SMALL PRECIPITATION CHANCES IN THE FORECAST.
UPPER LEVEL TROUGH BEGINS TO BREAK DOWN OVER THE GREAT LAKES
REGION AND HEIGHTS RISE OVER THE NORTHERN PLAINS LATE SUNDAY INTO
THE MIDDLE OF NEXT WEEK. THE 18.00Z GFS/ECMWF ARE INDICATING
UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES BY 00Z
THURSDAY. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL EARLY TO
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 643 AM CDT THU SEP 18 2014
COMPLEX WEATHER PATTERN OVER THE TAF SITES FOR THE NEXT SEVERAL
HOURS WITH VFR OR IFR CONDITIONS. A COLD FRONT IS MOVING OUT OF
WISCONSIN TOWARD MINNESOTA AT 1130Z. AN IFR CLOUD DECK WITH SOME
EMBEDDED IFR VSBYS HAS MADE ITS WAY WESTWARD TO THE MN/WI BORDER.
THIS HAS MADE STEADY WESTWARD PROGRESS OVERNIGHT.
AT KLSE...RIVER VALLEY STRATUS AND FOG WERE FOUND IN THE VALLEY
AND NOW WITH THE IFR CLOUD DECK MOVING OVER THE TOP...BELIEVE IT
WILL SIMPLY REINFORCE THE IFR CONDITIONS...MAKE IT LESS LOCAL TO
THE RIVER VALLEY...AND IMPACT AVIATION THROUGH THE MORNING.
AT KRST...THE WESTWARD PUSH TO THE IFR CIGS AND FRONT SHOULD SLOW
SOME WITH SUNRISE AND MIXING INCREASING. BUT IT IS STILL EARLY
AND HAVE DECIDED TO AT LEAST ADDRESS THE POSSIBILITY THAT THE IFR
CLOUD DECK COULD REACH KRST BEFORE HALTING ITS WESTWARD
PROGRESSION VIA A TEMPO IFR GROUP. CONFIDENCE IS LOWER ON
KRST...IF THE DECK CONTINUES WEST...THE MORNING TAF WILL BE VERY
SIMILAR TO KLSE WITH IFR THROUGH 16-17Z PREVAILING. UPDATES WILL
BE FORTHCOMING AS CONFIDENCE IN A SCENARIO GROWS.
BOTH SITES SHOULD SEE LIFTING CEILINGS BY LATE MORNING WITH A
DECREASE IN CLOUD THIS AFTERNOON AND A RETURN TO VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
344 AM CDT THU SEP 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERNS TODAY ARE CLOUD TRENDS.
LATEST 08Z SURFACE ANALYSIS SHOWS WEAK COLD FRONT EXTENDING FROM
EASTERN WISCONSIN INTO WESTERN MINNESOTA. LATEST FOG PRODUCT
SATELLITE IMAGERY INDICATES LOW LEVEL STRATUS OVER PORTIONS OF
NORTHERN AND EASTERN HALF OF WISCONSIN AND EAST CENTRAL
MINNESOTA. THIS LOW LEVEL STRATUS IS MOVING SOUTH AND WEST BEHIND
THE WEAK SURFACE FRONT.
THE 18.00Z GFS/NAM AND 18.06Z RAP APPEAR INITIALIZE AND HANDLE
MOVEMENT/EXPANSION OF LOW LEVEL STRATUS WELL INTO WESTERN WISCONSIN
EARLY THIS MORNING/TODAY PER THE 925MB RELATIVE HUMIDITY FIELDS. THE
BIG QUESTION WILL BE HOW LONG WILL THE LOW LEVEL STRATUS HANGS
AROUND THE FORECAST AREA TODAY. THE 18.00Z GFS/NAM AND 18.06Z RAP
SUGGEST THE CLOUDS WILL ERODE DUE TO DAYTIME HEATING AND LIFT BACK
NORTH INTO NORTHERN WISCONSIN AROUND 18Z TODAY. IF LOW LEVEL STRATUS
ERODES LATER IN THE AFTERNOON...THIS WILL HAVE IMPACTS ON FORECAST
HIGH TEMPERATURES FOR TODAY...ESPECIALLY OVER EASTERN PART OF THE
FORECAST AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU SEP 18 2014
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY INTO SATURDAY
NIGHT. THE LATEST 18.00Z GFS/NAM/ECMWF SHOW DECENT ISENTROPIC LIFT
AT 305K SURFACE BETWEEN 12-18Z FRIDAY AND ASSOCIATED 925-850MB
MOISTURE TRANSPORT INTO THE WESTERN FORECAST AREA. THE COMBINATION
OF ELEVATED INSTABILITY OF 0-6KM MOST UNSTABLE CAPE OF 300-800
J/KG OVER THE WESTERN FORECAST AREA AND THIS LIFT...WARRANTS A
SMALL PRECIPITATION CHANCE OVER THE WESTERN FORECAST AREA BETWEEN
12-18Z FRIDAY.
AFTER THIS INITIAL WEAK IMPULSE IN ASSOCIATION WITH WARM AIR
ADVECTION...THE 18.0ZZ GFS/NAM/ECMWF INDICATE MUCH OF THE
SOUTHERN FORECAST AREA BECOMES CAPPED AFTER 18Z FRIDAY...AS
SHORTWAVE RIDGE BUILDS INTO THE AREA AND FOCUSES LIFT/MOISTURE
TRANSPORT INTO NORTHERN WISCONSIN. HAVE ADJUSTED PRECIPITATION
CHANCES FURTHER NORTH AFTER 18Z FRIDAY. THE CAP BEGINS TO WEAKEN
AFTER 00Z SATURDAY ACROSS THE FORECAST AREA...IN ADDITION SURFACE
FRONT PUSHES ACROSS FORECAST AREA AND DEEP FORCING/MOISTURE
TRANSPORT/CONVERGENCE WILL ALLOW SHOWERS AND THUNDERSTORMS TO
DEVELOP IN THE 00-06Z SATURDAY TIMEFRAME AND MOVE NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT. ANY SEVERE THREAT
WITH THE THUNDERSTORMS LOOKS TO BE CONFINED NORTH OF THE
INTERSTATE 90 CORRIDOR...WHERE THE BETTER INSTABILITY AND SHEAR
WILL BE OVER THE FORECAST AREA. AT THIS TIME...THE SEVERE THREAT
LOOKS TO BE ISOLATED AND THE MAIN THREATS WOULD BE LARGE HAIL AND
DAMAGING WINDS.
SURFACE FRONT/SHORTWAVE TROUGH PUSHES SOUTH AND EAST OF FORECAST
AREA SATURDAY AND TAKING THE BULK OF LIFT AND BETTER INSTABILITY
SOUTH AND EAST OF FORECAST AREA. THE REGION WILL BE UNDER THE
INFLUENCE OF CYCLONIC FLOW SATURDAY...WITH STEEPENING LAPSE RATES
AND A COUPLE HUNDRED ELEVATED CAPE PER BUFKIT SOUNDINGS. SHOWERS
AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ACROSS THE FORECAST
AREA. HAVE LEFT SMALL PRECIPITATION CHANCES IN THE FORECAST.
UPPER LEVEL TROUGH BEGINS TO BREAK DOWN OVER THE GREAT LAKES
REGION AND HEIGHTS RISE OVER THE NORTHERN PLAINS LATE SUNDAY INTO
THE MIDDLE OF NEXT WEEK. THE 18.00Z GFS/ECMWF ARE INDICATING
UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES BY 00Z
THURSDAY. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL EARLY TO
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED SEP 17 2014
SATELLITE AND SURFACE OBSERVATIONS THIS EVENING INDICATE THE
STRATUS CLOUDS HAVE ADVANCED INTO NORTHERN WISCONSIN BUT ARE
MOVING SOUTH A SLOWER PACE THAN EARLIER EXPECTED. THE 18.00Z NAM
NOW SUGGESTS THESE CLOUDS WILL NOT MAKE INTO THE AREA BEFORE SOME
FOG CAN FORM AND THIS IS CONSISTENT WITH WHAT THE RAP HAS BEEN
SHOWING ALL EVENING. BASED ON THESE TRENDS HAVE GONE FOR A VALLEY
FOG EVENT AT KLSE WITH IFR CONDITIONS DEVELOPING AND PERSISTING
THROUGH THE MIDDLE OF THURSDAY MORNING BEFORE LIFTING. WITH A DEEP
LAYER OF LIGHT WINDS...SHOULD ALSO SEE SOME FOG FORM AT KRST WITH
MVFR/IFR VISIBILITIES EXPECTED. ONCE THE FOG LIFTS THURSDAY
MORNING...VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF THE
PERIOD AS HIGH PRESSURE DRIFTS ACROSS THE NORTHERN GREAT
LAKES/SOUTHERN ONTARIO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT WED SEP 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 318 PM CDT WED SEP 17 2014
AS OF MID AFTERNOON...WATER VAPOR IMAGERY COMBINED WITH 500 MB
RAP HEIGHTS SHOWED LONGWAVE TROUGHING OVER THE GREAT LAKES REGION
WITH SUBTLE SHORTWAVE MOVING THROUGH NORTHERN WISCONSIN. TO THE
WEST...THE REMNANTS OF OLDIE ARE LAID OUT ACROSS SOUTHWEST CONUS
IN THE MIDST OF A LARGE SCALE RIDGE OVER THE INTERMOUNTAIN WEST.
AT THE SURFACE...BACKDOOR COLD FRONT LIES FROM THE BOUNDARY
WATERS REGION OF NORTHERN MINNESOTA THROUGH THE U.P. OF
MICHIGAN...DENOTED BY NORTHEASTERLY FLOW AND LOW STRATUS IN ITS
WAKE. IT IS THIS FEATURE THAT WILL BE THE NEAR/SHORT TERM FORECAST
CONCERN.
17.12Z GUIDANCE IN REASONABLE AGREEMENT SHOWING THE FRONT
ADVANCING SOUTHWESTWARD TONIGHT...REACHING THE I-94 CORRIDOR OF
CENTRAL WISCONSIN AFTER MIDNIGHT. 925 TO 850 MB RH FIELDS SUPPORT
STRATUS DECK CONTINUING ITS MARCH...HOLDING UP JUST ALONG AND EAST
OF THE MS RIVER BY SUNRISE THURSDAY. INCREASED OVERNIGHT SKY COVER
QUITE A BIT ACROSS WEST CENTRAL WISCONSIN. TEMPERATURES DO FALL
OFF WITH ITS PASSAGE...SO STILL LOOKING AT LOWS IN THE UPPER 30S
FOR THOSE AREAS DESPITE CLOUD COVER.
THE REST OF THE FORECAST AREA WILL BE COMPLICATED BY FOG AND/OR
DEVELOPING STRATUS POTENTIAL OVERNIGHT. WIND PROFILES FROM
KLSE/KRST/KDEH AHEAD OF THIS FRONT ARE VERY LIGHT THROUGH
09Z...LESS THAN 10 KTS UP TO 700 MB...THOUGH BEGIN TO INCREASE
BETWEEN 09-12Z. ENVISION INITIALLY PATCHY TO MAYBE AREAS OF FOG
CONCENTRATED IN THE MS AND WISCONSIN RIVER VALLEYS/TRIBS BUT ALSO
GUIDANCE SUGGESTS PATCHY FOG IS POSSIBLE ACROSS NORTHEAST IOWA AND
SOUTHEAST MINNESOTA. AS WINDS AT BLUFF TOP INCREASE...FOG SHOULD
DISSIPATE AND BECOME BROKEN STRATUS. 17.12Z HI-RES MODELS AND SREF
PROBABILITIES SUGGEST THIS THINKING AS WELL.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 PM CDT WED SEP 17 2014
FOCUS IN THIS PERIOD IS ON SHOWER/STORM CHANCES FRIDAY AND
SATURDAY AS WEATHER SYSTEM PASSES THROUGH THE UPPER MIDWEST. BRIEF
UPPER LEVEL RIDGING FRIDAY BECOMES ZONAL FRIDAY AFTERNOON AS
SHORTWAVE TRAVERSES NORTHERN PLAINS. THERE COULD BE SOME FRIDAY
MORNING WARM AIR ADVECTION SHOWERS WEST OF THE MS RIVER BUT IS
LIKELY TO BE WEST OF THE FORECAST AREA. AS THE CAP
STRENGTHENS...THIS WILL SHUT OFF AND/OR MOVE PRECIP TO THE
NORTHEAST. THE BULK OF THE AREA WILL BE CAPPED OFF FRIDAY AS PLUME
OF WARM 700 MB AIR /+12C/ OFF THE HIGH PLAINS NOSES INTO THE UPPER
MIDWEST. THE GFS/NAM ARE AGGRESSIVE WITH THIS CAP...SHUTTING OFF
ANY PRECIP CHANCE DURING THE DAY UP TO KMSP/KEAU AREAS. STRONG
SOUTHERLY FLOW WILL MAKE FOR A BREEZY DAY...ESPECIALLY ACROSS OPEN
AREAS OF SOUTHERN MN. WIND GUSTS 25 TO 35 MPH LIKELY LATE MORNING
THROUGH AFTERNOON.
FINALLY BY FRIDAY EVENING SOME COOLING AND FALLING HEIGHTS WITH
SHORTWAVE TROUGH MOVING THROUGH SHOULD HELP TO BREAK CAP AND ALLOW
CONVECTION TO DEVELOP ACROSS CENTRAL MINNESOTA TO NORTHWEST
WISCONSIN. SHEAR PROFILES ARE IMPRESSIVE NOTED BY 0-6 KM BULK
VALUES 30+ KTS WITH SOME CURVATURE IN THE HODOGRAPHS IN THE
LOWEST 3 KM. AT THE SAME TIME...WARM CLOUD DEPTHS ARE 3.5 TO 4.0
KM...WHICH WILL LIMIT HIGHER HAIL THREAT BUT AID IN THE HEAVY RAIN
PRODUCTION. INITIATION LOOKS TO BE CENTRAL MINNESOTA TO NORTHWEST
WISCONSIN...THEN TRACK EAST/SOUTHEAST THROUGH THE NORTHERN HALF OF
THE FORECAST AREA LATE FRIDAY EVENING. THE BULK OF THE ACTIVITY
LOOKS TO BE IN THE 03-12Z TIME FRAME. SOME STRONGER TO SEVERE
STORMS ARE POSSIBLE INITIALLY...MAINLY DAMAGING WINDS AND HEAVY
RAIN. MARGINAL SEVERE HAIL THREAT. THE GREATEST THREAT IS NORTH
OF I-90.
STILL SOME TIMING DIFFERENCES BETWEEN 17.12Z GUIDANCE BUT COLD FRONT
SHOULD SLIP THROUGH 12-18Z ACROSS MUCH OF THE AREA. AHEAD OF
IT...WEAK CAP REMAINS IN THE PLACE WHICH COULD LIMIT COVERAGE OF
SHOWERS/STORMS WITH THE HIGHER CHANCES LOOKING TO BE NORTHEAST
IOWA INTO SOUTHWEST WISCONSIN.
COOL CANADIAN HIGH PRESSURE THEN LOOKS TO BUILD IN SUNDAY THROUGH
WEDNESDAY PROVIDING THE UPPER MIDWEST WITH SEVERAL
PLEASANT...SEASONABLY COOL DAYS. HIGHS IN THE MIDDLE/UPPER 60S AND
LOWS IN THE 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED SEP 17 2014
SATELLITE AND SURFACE OBSERVATIONS THIS EVENING INDICATE THE
STRATUS CLOUDS HAVE ADVANCED INTO NORTHERN WISCONSIN BUT ARE
MOVING SOUTH A SLOWER PACE THAN EARLIER EXPECTED. THE 18.00Z NAM
NOW SUGGESTS THESE CLOUDS WILL NOT MAKE INTO THE AREA BEFORE SOME
FOG CAN FORM AND THIS IS CONSISTENT WITH WHAT THE RAP HAS BEEN
SHOWING ALL EVENING. BASED ON THESE TRENDS HAVE GONE FOR A VALLEY
FOG EVENT AT KLSE WITH IFR CONDITIONS DEVELOPING AND PERSISTING
THROUGH THE MIDDLE OF THURSDAY MORNING BEFORE LIFTING. WITH A DEEP
LAYER OF LIGHT WINDS...SHOULD ALSO SEE SOME FOG FORM AT KRST WITH
MVFR/IFR VISIBILITIES EXPECTED. ONCE THE FOG LIFTS THURSDAY
MORNING...VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF THE
PERIOD AS HIGH PRESSURE DRIFTS ACROSS THE NORTHERN GREAT
LAKES/SOUTHERN ONTARIO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
913 PM MDT FRI SEP 19 2014
.UPDATE...
ISSUED AT 913 PM MDT FRI SEP 19 2014
A NUMBER OF OUTFLOW BOUNDARIES HAVE BEEN SITUATED ACROSS EASTERN
LARAMIE COUNTY THIS EVENING...AND INTERACTED WITH WHAT APPEARS
TO BE A PREFRONTAL TROUGH MOVING EAST ACROSS THE CWA TO MAINTAIN
DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE
I-80 CORRIDOR. A FEW SHOWERS CONTINUE TO POP UP AT THIS HOUR FROM
EASTERN LARAMIE COUNTY AND POINTS TO THE EAST...BUT THINK THE
MAIN SFC AND MIDLEVEL FORCING HAS PUSHED SOUTH AND EAST OF THE
CWA BASED ON SATELLITE IMAGERY. WILL KEEP WIDELY SCATTERED
COVERAGE FOR SHOWERS WITH MENTION OF ISO-T THROUGH 06Z FOR THIS
AREA...BUT THIS MAY BE OVERLY OPTIMISTIC BASED ON RADAR TRENDS
ALREADY TAKING A DOWNWARD TURN. THE MAIN SFC COLD FRONT LOOKS TO
BE JUST NORTH OF THE CWA AND WILL CONTINUE TO MOVE SOUTH
OVERNIGHT. FOCUSED HIGHEST CLOUD COVER ALONG THE LARAMIE RANGE
THROUGH THE EARLY MORNING HOURS AS MODELS HINT AT A SCT STRATUS
DECK ACCOMPANYING THE FRONT ALONG WITH NORTH-NORTHEAST UPSLOPE
FLOW. OTHERWISE...FORECAST IS IN GOOD SHAPE.
&&
.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 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 551 PM MDT FRI SEP 19 2014
ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH AROUND
02Z FROM VCTS KCYS TO KSNY. GUSTY WEST TO NORTHWEST WINDS WILL
EASE THROUGH SUNSET WITH WINDS REMAINING LIGHT THROUGH SATURDAY
AFTERNOON. WINDS WILL SHIFT TO THE NORTH TO NORTHEAST LATE
SATURDAY AFTERNOON...WITH GUSTS TO 20 KTS POSSIBLE ACROSS THE
WYOMING PLAINS AND NORTHERN NEBRASKA PANHANDLE.
&&
.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.
&&
$$
UPDATE...RJM
SHORT TERM...HAMMER
LONG TERM...FINCH
AVIATION...RJM
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
551 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 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 551 PM MDT FRI SEP 19 2014
ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH AROUND
02Z FROM VCTS KCYS TO KSNY. GUSTY WEST TO NORTHWEST WINDS WILL
EASE THROUGH SUNSET WITH WINDS REMAINING LIGHT THROUGH SATURDAY
AFTERNOON. WINDS WILL SHIFT TO THE NORTH TO NORTHEAST LATE
SATURDAY AFTERNOON...WITH GUSTS TO 20 KTS POSSIBLE ACROSS THE
WYOMING PLAINS AND NORTHERN NEBRASKA PANHANDLE.
&&
.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...RJM
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1145 AM MDT THU SEP 18 2014
.UPDATE...
ISSUED AT 1006 AM MDT THU SEP 18 2014
FOG HAS BEEN LIFTING ACROSS THE PANHANDLE LATE THIS MORNING. WENT
AHEAD AND TOOK FOG OUT OF THE FORECAST THE REST OF THE MORNING.
UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH NOON FRIDAY)
ISSUED AT 1145 AM MDT THU SEP 18 2014
FOG AND LOW STRATUS HAVE LIFTED ACROSS PORTIONS OF THE NEBRASKA
PANHANDLE LATE THIS MORNING...WITH VFR CONDITIONS EXPECTED THROUGH
THE DAY AND INTO TONIGHT. WINDS SHOULD REMAIN RELIATVELY LIGHT TODAY
WITH SOUTH WINDS STRENGTHENING OVER THE NEBRASKA PANHANDLE TONIGHT
AS A SURFACE LOW MOVES EASTWARD OVER THE NORTHERN GREAT PLAINS. VFR
CONDITIONS WILL PREVAIL ACROSS SOUTHEAST WYOMING THROUGH THE PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...TJT
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1008 AM MDT THU SEP 18 2014
.UPDATE...
ISSUED AT 1006 AM MDT THU SEP 18 2014
FOG HAS BEEN LIFTING ACROSS THE PANHANDLE LATE THIS MORNING. WENT
AHEAD AND TOOK FOG OUT OF THE FORECAST THE REST OF THE MORNING.
UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 526 AM MDT THU SEP 18 2014
NEBRASKA TAFS...AREAS OF IFR CEILINGS AND VISIBILITIES IN LOW
CLOUDS AND FOG THROUGH 9 AM...OTHERWISE VFR PREVAILS. WIND GUSTS
OF 20 TO 30 KNOTS LATE THIS MORNING AND THIS AFTERNOON.
WYOMING TAFS...VFR PREVAILS. WIND GUSTS OF 20 TO 30 KNOTS LATE
THIS MORNING AND THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
529 AM MDT THU SEP 18 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 526 AM MDT THU SEP 18 2014
NEBRASKA TAFS...AREAS OF IFR CEILINGS AND VISIBILITIES IN LOW
CLOUDS AND FOG THROUGH 9 AM...OTHERWISE VFR PREVAILS. WIND GUSTS
OF 20 TO 30 KNOTS LATE THIS MORNING AND THIS AFTERNOON.
WYOMING TAFS...VFR PREVAILS. WIND GUSTS OF 20 TO 30 KNOTS LATE
THIS MORNING AND THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
332 AM MDT THU SEP 18 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM MDT THU SEP 18 2014
PREDAWN WATER VAPOR LOOP DEPICTED A UPPER RIDGE AXIS FROM THE FOUR
CORNERS TO THE NORTHERN ROCKY MOUNTAINS. REMNANT LOW FROM TROPICAL
DEPRESSION ODILE WAS DRIFTING NORTHEAST ACROSS SOUTHEAST AZ. A LARGE
PLUME OF SUBTROPICAL MOISTURE EXPANDED EAST ACROSS THE SOUTHERN PLAINS
AND LOWER MS VALLEY. A STATIONARY SURFACE FRONT FROM NORTHEAST WY
TO SOUTHWEST KS SEPARATED DEW POINTS IN THE 50S EAST FROM 30S WEST.
BOTH THE HRRR AND SREF MODELS PROG WEAK UPSLOPE AND L0W LEVEL
MOISTURE CONVERGENCE FROM NORTHWEST KS INTO WESTERN NE...WITH
LOW STRATUS AND PATCHY FOG DEVELOPING BETWEEN 3 AM AND 6 AM FOR
MUCH OF THE NE PANHANDLE. THE FOG AND STRATUS SHOULD DISSIPATE BY
LATE MORNING.
A BLEND OF THE 00Z SHORT RANGE MODEL GUIDANCE PROGS THE UPPER RIDGE
TO THE WEST TO BE SITUATED OVER THE FRONT RANGE THIS AFTERNOON AND
CENTRAL/SOUTHERN GREAT PLAINS FRIDAY MORNING AS A UPPER TROUGH
TRAVERSES THE NORTHERN TIER OF THE NATION. A LEE SURFACE TROUGH AND
MID LEVEL THERMAL RIDGE JUXTAPOSED OVER THE CWA WILL PROVIDE AND
DRY AND QUITE WARM AFTERNOON WITH 700MB TEMPERATURES TOPPING OUT
AROUND 15C. LOW ELEVATIONS CAN EXPECT HIGHS IN THE 80S...WITH 90
TO 95 DEGREES FOR THE PLAINS OF EASTERN WY AND WESTERN NE. THESE
READINGS WILL FLIRT WITH RECORD TERRITORY FOR SOME LOCATIONS. SOUTH
TO SOUTHWEST WINDS WILL BE BREEZY AT TIMES...ESPECIALLY FOR PARTS
OF WESTERN NE AND SOUTH CENTRAL WY.
THE LEADING EDGE OF PACIFIC MOISTURE WILL ENCROACH ON SOUTH CENTRAL
WY LATER TONIGHT AS A WEAK COLD FRONT MOVES INTO WESTERN WY.
ISOLATED SHOWERS/TSTORMS WILL BE POSSIBLE OVER WESTERN CARBON COUNTY.
FRIDAY WILL BE MORE UNSETTLED AS THE FRONT ADVANCES EAST THROUGH THE
CWA...WITH ISOLATED TO SCATTERED SHOWERS/TSTORMS. IT WILL TURN COOLER
AS 700MB TEMPERATURES FALL TO AROUND 11C. WINDS WILL SHIFT TO
NORTHWESTERLY FOLLOWING FROPA. CONVECTIVE PRECIPITATION WILL TAPER
OFF FRIDAY NIGHT WITH THE PASSAGE OF THE UPPER TROUGH AND ADVECTION
OF DRIER STABLE AIR FROM THE WEST.
UPPER RIDGE REASSERTS ITSELF OVER THE FOUR CORNERS SATURDAY. WEAK
UPSLOPE AND INSTABILITY MAY TRIGGER A FEW SHOWERS OR TSTORMS OVER
THE SOUTHERN MOUNTAINS IN THE AFTERNOON. IT WILL BE 5 TO 10 DEGREES
COOLER THAN FRIDAY WITH 700MB TEMPERATURES AROUND 7C. HIGHS WILL
BE IN THE 70S TO LOWER 80S LOWER ELEVATIONS WITH 50S AND 60S FOR
THE HIGH COUNTRY. NORTHEASTERLY WINDS WILL BE BE BREEZY AT TIMES
DURING THE AFTERNOON ACROSS PORTIONS OF THE NE PANHANDLE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM MDT THU SEP 18 2014
SATURDAY NIGHT/SUNDAY...ISOLATED SATURDAY EVENING THUNDERSTORMS OVER
THE SNOWY AND SIERRA MADRE RANGES...OTHERWISE DRY SATURDAY NIGHT.
NEXT SHORTWAVE TROUGH ALOFT MOVES OVER WESTERN UTAH SUNDAY AFTERNOON
SPREADING CLOUDS AND SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR
SOUTHERN COUNTIES SOUTH OF A RAWLINS TO SCOTTSBLUFF LINE.
MONDAY...SHORTWAVE TROUGH PROGGED TO TRAVERSE ACROSS OUR COUNTIES IN
THE AFTERNOON...SPAWNING SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE
25.
TUESDAY...AS THE SHORTWAVE TROUGH IS PROGGED TO MOVE EAST OF OUR
COUNTIES...WILL SEE A CORRESPONDING DECREASE IN SHOWER AND THUNDERSTORM
COVERAGE IN THE AFTERNOON AND EVENING.
WEDNESDAY...FLOW ALOFT BECOMES SOUTHWEST IN ADVANCE OF THE GREAT BASIN
LARGE SCALE TROUGH...AND WITH MINIMAL LOW AND MID LEVEL MOISTURE...
SHOWERS AND THUNDERSTORMS LOOK ISOLATED AT BEST ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM MDT WED SEP 17 2014
WYOMING TAFS...VFR PREVAILS.
NEBRASKA TAFS...AREAS OF IFR DEVELOPING THROUGH 15Z...OTHERWISE
VFR PREVAILS.
&&
.FIRE WEATHER...
ISSUED AT 230 AM MDT THU SEP 18 2014
WARM AND DRY CONDITIONS WILL CONTINUE TODAY WITH LOWEST HUMIDITIES
FROM 15 TO 25 PERCENT DURING THE AFTERNOON. WIND GUSTS WILL PEAK
AROUND 20 MPH. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN
FRIDAY AND FRIDAY NIGHT AS THE REMNANT CIRCULATION FROM ODILE MOVES
ACROSS SOUTHERN COLORADO AND WEAK FRONT PASSES THROUGH SOUTHEAST
WYOMING AND WESTERN NEBRASKA. SATURDAY WILL BE DRY AND COOLER AS
HIGH PRESSURE DOMINATES THE DISTRICTS. A SLOW MOVING PACIFIC UPPER
LOW AND SUBTROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SUNDAY THROUGH TUESDAY...WITH SLIGHTLY COOLER THAN
NORMAL TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...JAMSKI
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
940 PM PDT FRI SEP 19 2014
.SYNOPSIS...
A SLOW MOVING TROUGH WILL CONTINUE TO BRING COOLER WEATHER AND A
DEEP MARINE LAYER THROUGH SUNDAY. PATCHY DRIZZLE IS POSSIBLE AGAIN
LATE TONIGHT AND TOMORROW MORNING. A WARMING TREND AND SHALLOWER
MARINE LAYER IS EXPECTED MONDAY THROUGH WEDNESDAY AS HIGH PRESSURE
BUILDS ALOFT.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
THE MARINE LAYER IS A LITTLE DEEPER THAN LAST NIGHT BUT THE STRATUS
COVERAGE IS NOT NEARLY AS WIDESPREAD. ONLY SCATTERED LOW CLOUDS
COVER THE COASTAL WATERS THIS EVENING. STILL EXPECT THE CLOUDS
INCREASE OVERNIGHT AND SPREAD INTO THE VALLEYS...BUT THE ADVANCING
UPPER LOW COULD DISRUPT THE COVERAGE SO IT MAY NOT BE THE UNIFORM
CLOUD DECK THAT WE SAW THIS MORNING. 00Z WRF STILL OUTPUTTING LIGHT
QPF SO THERE MAY BE AREAS OF DRIZZLE AGAIN TOMORROW MORNING.
WATER VAPOR IMAGE SHOWS THE UPPER TROUGH WEST OF PT CONCEPTION THIS
EVENING. IT WILL MOVE EAST TONIGHT...THEN BRIEFLY STALL OVER PT
CONCEPTION SATURDAY BEFORE EJECTING NORTHEAST TOWARD NEVADA SATURDAY
NIGHT AND SUNDAY. THE NAM4 AND CANSAC GENERATE STILL GENERATE SMALL
QPF OVER THE SBD/RIV COUNTY MTNS SATURDAY AFTERNOON WITH THE PASSAGE
OF THE UPPER VORT MAX...SO WILL HOLD ONTO THE SLT CHANCE FOR
SHRA/TSTMS THERE. THE WRFEMS AND HRRR MODELS ARE DRY.
THE LOW MOVES ACROSS NEVADA SUNDAY WITH A SMALL INCREASE IN HTS AND
A FEW DEGREES OF WARMING. GREATER WARMING AND A SHALLOWER MARINE
LAYER MON-WED FROM WEAK RIDGING BUILDING OVER THE SOUTHWEST. THE
GFS SHOWS SOME INCREASE IN PRECIPITABLE WATER WEDNESDAY AS LOW LEVEL
WINDS SHIFT SOUTHERLY...BUT PRECIP IS NOT EXPECTED.
LONG RANGE OUTLOOK LATE NEXT WEEK...THE GFS AND GEM FORECAST A DEEP
TROUGH TO MOVE INTO THE WEST COAST THURSDAY THROUGH SATURDAY WHICH
WOULD BRING COOLING...A DEEPER MARINE LAYER AND GUSTY MTN AND DESERT
WINDS. THE OUTLIER IS THE ECMWF WHICH HOLDS ONTO WEAK RIDGING INTO
THE WEEKEND. THERE IS A 100DM HEIGHT SPREAD BETWEEN THE MODELS WHICH
IS SIGNIFICANT. HAVE TRENDED TOWARD ECMWF SINCE IT HAS BEEN
PERFORMING BETTER THAN THE GFS LATELY...AND HAVE TEMPERED THE
COOLING SOMEWHAT IN THE THU-SAT TIME FRAME.
&&
.AVIATION...
200300Z...LOW CLOUDS WILL MOVE ASHORE THROUGH THE EVENING WITH
BASES 1500-2000 FEET MSL AND SPREAD INTO INLAND VALLEYS OVERNIGHT.
TOPS WILL BE AROUND 3000 FEET. LOCAL VIS 3-5SM IN FAR INLAND
VALLEYS. SCATTER OUT SATURDAY BY 17-19Z. OTHERWISE...SKIES WILL BE
CLEAR AND VIS UNRESTRICTED THROUGH SATURDAY.
ON SATURDAY AFTERNOON IN THE MOUNTAINS THERE WILL BE SOME CUMULUS
BASED AROUND 8000 FEET AND A VERY SMALL CHANCE OF THUNDERSTORMS OVER
THE MOUNTAINS OF RIVERSIDE/SAN BERNARDINO COUNTIES.
&&
.MARINE...
800 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
&&
.SKYWARN...
SPOTTER ACTIVATION WILL NOT BE NEEDED THIS WEEKEND.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MOEDE
AVIATION/MARINE/BEACHES...MM
AREA FORECAST DISCUSSION
NWS JACKSON KY
413 AM EDT SAT SEP 20 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 355 AM EDT SAT SEP 20 2014
EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED
OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST
INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US...
A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES
WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID
MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT
LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN
INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE
IS MOVING ACROSS THE CANADIAN PLAINS.
THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK
ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO
FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING
NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US.
DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW
PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND
SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED
SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT
WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE
ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT
SHOULD BE CLOSE TO EXITING INTO VA.
SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED
OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS
LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE
RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER
NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH
SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS
SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD
GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A
COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS
FOG WILL TEND TO DISSIPATE AS WELL.
THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE
AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON.
THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO
DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY
ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE
LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS
BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO
GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH
WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS.
THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE
ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH
BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD
FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH
IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF
CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME.
ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE
CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER
TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS
WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY
WINDS...PENDING THE DEGREE OF INSTABILITY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM EDT SAT SEP 20 2014
A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY.
MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME
OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR
OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST
SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE
PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE
DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS
SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS
ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF
THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER
COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH
CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME
CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE
COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO
THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD
FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE
EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO
INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT
DID NOT MENTION FOG AT THIS TIME.
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 DURING
THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO
THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF
STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL
CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER
OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS
HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND.
MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE
LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT
LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 150 AM EDT SAT SEP 20 2014
ASIDE FROM VALLEY FOG DEVELOPING...AND THEN LIFTING AND DISSIPATING
THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL
DURING THE PERIOD. A COLD FRONT AND ASSOCIATED INCREASE IN CLOUDS IS
EXPECTED LATE IN THE PERIOD. THE FOG IS AGAIN EXPECTED TO FOLLOW ITS
TYPICAL LATE SUMMER/EARLY AUTUMN PATTERN OF DEVELOPING FIRST IN DEEP
VALLEYS AND THEN GROWING IN BREADTH AND DEPTH...WITH THE POTENTIAL TO
BEGIN TO REACH SOME RIDGES AND OPEN TERRAIN BY DAWN...SUCH AS MVFR AT
SJS IF WINDS SLACKEN AND POSSIBLY MVFR AT SME WHERE THE CURRENT
DEWPOINT DEPRESSION IS LOW BUT THERE ARE SCT CLOUDS AS WELL. THE
LARGER RECENT OBSERVED DEWPOINT DEPRESSION OF 7 AT LOZ POINTS TOWARD
ANY FOG THAT DEVELOPS BEING IN THE VFR RANGE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
325 AM EDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 140 AM EDT SAT SEP 20 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND
TRENDS. THIS LED TO SLIGHTLY COLDER MIN T IN A COUPLE OF SPOTS ACROSS
THE NORTH...WITH THE MAIN CHANGE BEING MORE FOG IN THE GRIDS FOR
VALLEY LOCATIONS OUTSIDE OF THE HIGHEST TERRAIN WHERE THE PRESSURE
GRADIENT WAS WEAKER. WE HAVE RECEIVED A SPOTTER REPORT OF DENSE FOG
NEAR THE RED RIVER IN POWELL COUNTY AND 11-3.9 SAT IMAGERY SUPPORTS
VALLEY FOG AT PRESENT IN PARTS OF THE LIKING...BIG SANDY...KENTUCKY
AND RED RIVER VALLEYS. SOME OF THE FOG SHOULD AGAIN BE DENSE
GENERALLY ALONG THE LARGER CREEKS AND STREAMS AND ESPECIALLY RIVERS
AND LARGER LAKES. THE PRESSURE GRADIENT IS EXPECTED TO RELAX A BIT
OVERNIGHT ACROSS THE SOUTHEAST PART OF THE CWA SO OUTSIDE OF WHERE
SOME CLOUDS DEVELOP IN THE WARM SECTOR...VALLEY FOG SHOULD ALSO
DEVELOP THERE TOWARD DAWN.
SOME OF THE GUIDANCE INDICATES THE POTENTIAL FOR A FEW STRAY SHOWERS
AS A WEAK DISTURBANCE APPROACHES...MAINLY ACROSS THE WESTERN AND
NORTHWESTERN PARTS OF THE CWA LATER TONIGHT INTO EARLY ON SATURDAY.
CONFIDENCE IN THIS IS NOT ALL THAT HIGH...BUT IT DOES HAVE SUPPORT
FROM THE NAM...SOME OF THE RECENT HRRR RUNS AND SOME PRIOR BUT NOT
THE MOST RECENT RAP RUN. WE WILL CONTINUE TO EVALUATE THIS POTENTIAL
FOR THE SCHEDULED MORNING FORECAST RELEASE.
UPDATE ISSUED AT 1027 PM EDT FRI SEP 19 2014
USED OBSERVED TEMPERATURES AND DEW POINTS TO ADJUST HOURLY GRIDS FOR
TONIGHT...BLENDING TOWARD THE PREEXISTING FORECAST BY MORNING. NO
SUBSTANTIVE CHANGES TO THE OVERALL FORECAST WERE MADE.
UPDATE ISSUED AT 729 PM EDT FRI SEP 19 2014
HAVE UPDATED TO ALLOW FOR A FASTER DROP IN VALLEY TEMPS THIS
EVENING. ALSO...REDUCED SKY COVER FOR MOST AREAS THIS EVENING.
MESOSCALE MODELS ARE PERSISTENT IN SHOWING CLOUDS DEVELOPING NEAR OUR
WESTERN BORDER LATE TONIGHT INTO SATURDAY MORNING...A WELL AS SOME
SHOWERS. HAVE ACCOUNTED FOR A FEW CLOUDS...BUT KEPT THE FORECAST IN
THE JKL FORECAST AREA DRY AT THIS POINT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 307 PM EDT FRI SEP 19 2014
A LARGE DOME OF HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EAST
COAST INTO THE WEEKEND...PROVIDING A DRY START TO THE WEEKEND. STILL
A REMOTE CHANCE OF AN ISOLATED SHOWER ACROSS PIKE COUNTY LATER THIS
EVENING...BUT CHANCES SEEM TO BE DIMINISHING WITH EVERY HOUR THAT
PASSES. THE CU JUST DOES NOT LOOK ALL THAT IMPRESSIVE.
REGARDLESS...UNTIL INSTABILITY WANES THIS EVENING CANNOT RULE OUT A
BRIEF POP UP SHOWER. SKIES WILL CLEAR OUT AGAIN TONIGHT. WITH
DEW POINTS CLIMBING HIGHER TODAY...AND CLEARING SKIES...ANOTHER NIGHT
OF FOG CAN BE EXPECTED ACROSS THE AREA. SHOULD BE A FAIRLY TYPICAL
FOG FOR THIS TIME OF YEAR. HIGHS WILL CLIMB TO THE HIGHEST READINGS
OF THE WEEK ON SATURDAY AS TEMPERATURES CLIMB INTO THE LOW 80S DURING
THE AFTERNOON. CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT AS A
COLD FRONT PUSHES SOUTH INTO THE OHIO RIVER VALLEY. PRECIPITATION
ASSOCIATED WITH THIS BOUNDARY COULD MAKE IT INTO AREAS NORTH OF 1-64
PRIOR TO 12Z SUNDAY...BUT IT APPEARS THE MAIN PRECIPITATION WITH THE
FRONT SHOULD COME COME LATER ON SUNDAY. WITH CLOUDS AND SURFACE
MOISTURE INCREASING SATURDAY NIGHT...A MILDER NIGHT IS ON TAP WITH
LOWS ONLY INTO THE 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM EDT SAT SEP 20 2014
A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY.
MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME
OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR
OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST
SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE
PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE
DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS
SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS
ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF
THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER
COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH
CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME
CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE
COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO
THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD
FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE
EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO
INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT
DID NOT MENTION FOG AT THIS TIME.
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 DURING
THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO
THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF
STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL
CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER
OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS
HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND.
MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE
LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT
LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 150 AM EDT SAT SEP 20 2014
ASIDE FROM VALLEY FOG DEVELOPING...AND THEN LIFTING AND DISSIPATING
THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL
DURING THE PERIOD. A COLD FRONT AND ASSOCIATED INCREASE IN CLOUDS IS
EXPECTED LATE IN THE PERIOD. THE FOG IS AGAIN EXPECTED TO FOLLOW ITS
TYPICAL LATE SUMMER/EARLY AUTUMN PATTERN OF DEVELOPING FIRST IN DEEP
VALLEYS AND THEN GROWING IN BREADTH AND DEPTH...WITH THE POTENTIAL TO
BEGIN TO REACH SOME RIDGES AND OPEN TERRAIN BY DAWN...SUCH AS MVFR AT
SJS IF WINDS SLACKEN AND POSSIBLY MVFR AT SME WHERE THE CURRENT
DEWPOINT DEPRESSION IS LOW BUT THERE ARE SCT CLOUDS AS WELL. THE
LARGER RECENT OBSERVED DEWPOINT DEPRESSION OF 7 AT LOZ POINTS TOWARD
ANY FOG THAT DEVELOPS BEING IN THE VFR RANGE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
155 AM EDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 140 AM EDT SAT SEP 20 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND
TRENDS. THIS LED TO SLIGHTLY COLDER MIN T IN A COUPLE OF SPOTS ACROSS
THE NORTH...WITH THE MAIN CHANGE BEING MORE FOG IN THE GRIDS FOR
VALLEY LOCATIONS OUTSIDE OF THE HIGHEST TERRAIN WHERE THE PRESSURE
GRADIENT WAS WEAKER. WE HAVE RECEIVED A SPOTTER REPORT OF DENSE FOG
NEAR THE RED RIVER IN POWELL COUNTY AND 11-3.9 SAT IMAGERY SUPPORTS
VALLEY FOG AT PRESENT IN PARTS OF THE LIKING...BIG SANDY...KENTUCKY
AND RED RIVER VALLEYS. SOME OF THE FOG SHOULD AGAIN BE DENSE
GENERALLY ALONG THE LARGER CREEKS AND STREAMS AND ESPECIALLY RIVERS
AND LARGER LAKES. THE PRESSURE GRADIENT IS EXPECTED TO RELAX A BIT
OVERNIGHT ACROSS THE SOUTHEAST PART OF THE CWA SO OUTSIDE OF WHERE
SOME CLOUDS DEVELOP IN THE WARM SECTOR...VALLEY FOG SHOULD ALSO
DEVELOP THERE TOWARD DAWN.
SOME OF THE GUIDANCE INDICATES THE POTENTIAL FOR A FEW STRAY SHOWERS
AS A WEAK DISTURBANCE APPROACHES...MAINLY ACROSS THE WESTERN AND
NORTHWESTERN PARTS OF THE CWA LATER TONIGHT INTO EARLY ON SATURDAY.
CONFIDENCE IN THIS IS NOT ALL THAT HIGH...BUT IT DOES HAVE SUPPORT
FROM THE NAM...SOME OF THE RECENT HRRR RUNS AND SOME PRIOR BUT NOT
THE MOST RECENT RAP RUN. WE WILL CONTINUE TO EVALUATE THIS POTENTIAL
FOR THE SCHEDULED MORNING FORECAST RELEASE.
UPDATE ISSUED AT 1027 PM EDT FRI SEP 19 2014
USED OBSERVED TEMPERATURES AND DEW POINTS TO ADJUST HOURLY GRIDS FOR
TONIGHT...BLENDING TOWARD THE PREEXISTING FORECAST BY MORNING. NO
SUBSTANTIVE CHANGES TO THE OVERALL FORECAST WERE MADE.
UPDATE ISSUED AT 729 PM EDT FRI SEP 19 2014
HAVE UPDATED TO ALLOW FOR A FASTER DROP IN VALLEY TEMPS THIS
EVENING. ALSO...REDUCED SKY COVER FOR MOST AREAS THIS EVENING.
MESOSCALE MODELS ARE PERSISTENT IN SHOWING CLOUDS DEVELOPING NEAR OUR
WESTERN BORDER LATE TONIGHT INTO SATURDAY MORNING...A WELL AS SOME
SHOWERS. HAVE ACCOUNTED FOR A FEW CLOUDS...BUT KEPT THE FORECAST IN
THE JKL FORECAST AREA DRY AT THIS POINT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 307 PM EDT FRI SEP 19 2014
A LARGE DOME OF HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EAST
COAST INTO THE WEEKEND...PROVIDING A DRY START TO THE WEEKEND. STILL
A REMOTE CHANCE OF AN ISOLATED SHOWER ACROSS PIKE COUNTY LATER THIS
EVENING...BUT CHANCES SEEM TO BE DIMINISHING WITH EVERY HOUR THAT
PASSES. THE CU JUST DOES NOT LOOK ALL THAT IMPRESSIVE.
REGARDLESS...UNTIL INSTABILITY WANES THIS EVENING CANNOT RULE OUT A
BRIEF POP UP SHOWER. SKIES WILL CLEAR OUT AGAIN TONIGHT. WITH
DEW POINTS CLIMBING HIGHER TODAY...AND CLEARING SKIES...ANOTHER NIGHT
OF FOG CAN BE EXPECTED ACROSS THE AREA. SHOULD BE A FAIRLY TYPICAL
FOG FOR THIS TIME OF YEAR. HIGHS WILL CLIMB TO THE HIGHEST READINGS
OF THE WEEK ON SATURDAY AS TEMPERATURES CLIMB INTO THE LOW 80S DURING
THE AFTERNOON. CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT AS A
COLD FRONT PUSHES SOUTH INTO THE OHIO RIVER VALLEY. PRECIPITATION
ASSOCIATED WITH THIS BOUNDARY COULD MAKE IT INTO AREAS NORTH OF 1-64
PRIOR TO 12Z SUNDAY...BUT IT APPEARS THE MAIN PRECIPITATION WITH THE
FRONT SHOULD COME COME LATER ON SUNDAY. WITH CLOUDS AND SURFACE
MOISTURE INCREASING SATURDAY NIGHT...A MILDER NIGHT IS ON TAP WITH
LOWS ONLY INTO THE 60S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 PM EDT FRI SEP 19 2014
ALL OF THE WEATHER IS AT THE FRONT END OF THIS FORECAST PERIOD AS A
COLD FRONT IS SET TO SWEEP QUICKLY ACROSS THE AREA ON SUNDAY.
MOISTURE RETURN IN ADVANCE OF THE FRONT IS NOT GREAT WITH PWATS ONLY
CREEPING UP TO ABOUT 1.5 INCHES IN A THIN RIBBON. COUPLED WITH ONLY
WEAK INSTABILITY...ANTICIPATE A NARROW BAND OF SHOWERS AND A FEW
THUNDERSTORMS TO ACCOMPANY THE FRONT DURING THE DAY ON SUNDAY. THE
BULK OF THIS ACTIVITY SHOULD BE TO OUR SOUTHEAST BY SUNDAY EVENING.
FOLLOWING THIS FRONTAL PASSAGE...A LARGE DOME OF HIGH PRESSURE WILL
SLIDE ACROSS THE OHIO VALLEY. COUPLED WITH A BUILDING RIDGE ALOFT...
THIS SHOULD RESULT IN A PROLONGED PERIOD OF DRY WEATHER WITH
PLEASANT TEMPERATURES NEXT WEEK. THERE IS ONE POSSIBLE FLY IN THE
OINTMENT THOUGH AS FORECAST MODELS HINT THAT A WEAK UPPER LOW MAY
GET TRAPPED TO THE SOUTH OF THE UPPER RIDGE. ALL SIGNS CURRENTLY ARE
THAT ANY ASSOCIATED MOISTURE WITH THIS LOW WOULD STAY TO OUR SOUTH
AND EAST SO WILL NOT GIVE THIS ANY PLAY IN OUR LOCAL FORECAST AT
THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 150 AM EDT SAT SEP 20 2014
ASIDE FROM VALLEY FOG DEVELOPING...AND THEN LIFTING AND DISSIPATING
THROUGH 13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL
DURING THE PERIOD. A COLD FRONT AND ASSOCIATED INCREASE IN CLOUDS IS
EXPECTED LATE IN THE PERIOD. THE FOG IS AGAIN EXPECTED TO FOLLOW ITS
TYPICAL LATE SUMMER/EARLY AUTUMN PATTERN OF DEVELOPING FIRST IN DEEP
VALLEYS AND THEN GROWING IN BREADTH AND DEPTH...WITH THE POTENTIAL TO
BEGIN TO REACH SOME RIDGES AND OPEN TERRAIN BY DAWN...SUCH AS MVFR AT
SJS IF WINDS SLACKEN AND POSSIBLY MVFR AT SME WHERE THE CURRENT
DEWPOINT DEPRESSION IS LOW BUT THERE ARE SCT CLOUDS AS WELL. THE
LARGER RECENT OBSERVED DEWPOINT DEPRESSION OF 7 AT LOZ POINTS TOWARD
ANY FOG THAT DEVELOPS BEING IN THE VFR RANGE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...ABE
AVIATION...JP
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
348 AM MDT SAT SEP 20 2014
.SYNOPSIS...
VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO
WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER MOISTURE
WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER AND
THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF THE
EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A DISTURBANCE
ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW MOISTURE
FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD EASTWARD INTO NORTHWEST
NEW MEXICO MONDAY AND MOST AREAS TUESDAY. MEANWHILE... TEMPERATURES
WILL REMAIN GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW
NORMAL ACROSS THE EAST. BY THE MIDDLE OF NEXT WEEK...A DRYING
TREND WILL TAKE A STRONGER HOLD ON THE AREA...AND TEMPERATURES
WILL BE NEAR TO SLIGHTLY ABOVE NORMAL EXCEPT FOR THE SOUTHEAST
PLAINS WHERE COOLER THAN AVERAGE TEMPERATURE WILL LIKELY LINGER.
&&
.DISCUSSION...
EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE
CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO
DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST
SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK.
VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS
WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS
EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO
GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS
POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER
WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE
EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS
CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY.
AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX
TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS
ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC
MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED.
OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND
UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING
HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE
NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH
TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY
AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE
INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN
SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY
WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE
ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE
EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN
EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY
SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE-
SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO
THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM
MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY
LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR
WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES.
STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS
DEVELOP SUNDAY PM NW ZONES.
CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH
PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM
NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD
FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT
ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE
DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH
INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY
ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR
REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE
WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL
PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE
POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL
EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ
&&
.FIRE WEATHER...
UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT
DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL
SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE
EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM
TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION
EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING
RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN
ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED
ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC
MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO
MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP
ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL
MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE.
AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS
EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR
NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL
WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION
RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40
CORRIDOR.
MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES
IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL
WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO
CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY
ALONG AND NORTH OF I40.
A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA
STARTING TUE INTO AT LEAST THU...THOUGH 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, THOUGH NOT
DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO
APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL
DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS
DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS
POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF
STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN
CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43
&&
.AVIATION...
06Z TAF CYCLE
IFR CIGS WORKING INTO THE EASTERN PLAINS OVERNIGHT AND IN TAFS FOR
TCC...ROW...AND LVS. RIDGE BUILDING NORTHWARD ACROSS NM IN THE
WAKE OF ODILE...AS SURFACE LOW OVER NORTHERN MEXICO IMPARTS
EASTERLY COMPONENTS TO SURFACE WINDS THROUGH THE DAY ON SATURDAY.
GUSTS SQUIRTING THROUGH CENTRAL MT CHAIN GAPS OVER THE RIO GRANDE
VALLEY REFLECTED IN G30KT WINDS AT ABQ AND SAF FROM 01Z ONWARD SAT
EVENING. NEXT APPROACHING SYSTEM OVER CENTRAL CALIFORNIA WILL
SUPPORT SOME ISOLATED SHOWERS DRIFTING INTO WESTERN NEW MEXICO AND
IN TAFS FOR GUP AND FMN. OVERNIGHT MT OBSCURATION OVER THE
NORTHERN MTS AND ACROSS THE SOUTHERN TIER LATE SAT NIGHT.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 88 60 85 56 / 5 30 30 40
DULCE........................... 87 49 80 47 / 10 30 40 50
CUBA............................ 84 51 78 51 / 10 20 40 40
GALLUP.......................... 85 51 80 48 / 10 30 40 40
EL MORRO........................ 79 50 75 49 / 10 30 40 50
GRANTS.......................... 83 54 78 52 / 10 30 40 40
QUEMADO......................... 79 53 75 52 / 20 30 50 40
GLENWOOD........................ 83 52 82 54 / 30 30 30 30
CHAMA........................... 80 43 75 42 / 10 30 40 60
LOS ALAMOS...................... 81 57 74 55 / 10 20 40 40
PECOS........................... 77 53 69 52 / 10 30 50 50
CERRO/QUESTA.................... 78 48 75 48 / 10 20 40 40
RED RIVER....................... 71 44 66 44 / 10 30 50 50
ANGEL FIRE...................... 74 38 70 41 / 10 30 50 50
TAOS............................ 81 50 73 49 / 10 20 30 40
MORA............................ 77 50 68 50 / 10 30 50 50
ESPANOLA........................ 86 55 79 55 / 10 20 30 30
SANTA FE........................ 80 55 74 55 / 10 20 40 40
SANTA FE AIRPORT................ 84 55 77 55 / 10 20 40 30
ALBUQUERQUE FOOTHILLS........... 84 61 78 61 / 10 20 40 30
ALBUQUERQUE HEIGHTS............. 85 63 80 62 / 10 20 30 30
ALBUQUERQUE VALLEY.............. 86 60 81 61 / 10 20 30 30
ALBUQUERQUE WEST MESA........... 87 61 82 61 / 10 20 30 30
LOS LUNAS....................... 86 58 81 58 / 10 20 30 30
RIO RANCHO...................... 89 61 83 61 / 10 20 30 30
SOCORRO......................... 86 62 83 62 / 10 30 40 40
SANDIA PARK/CEDAR CREST......... 82 57 78 57 / 10 30 40 40
TIJERAS......................... 83 57 78 57 / 10 30 40 40
MORIARTY/ESTANCIA............... 81 49 74 50 / 10 30 50 40
CLINES CORNERS.................. 77 54 70 54 / 10 40 60 50
GRAN QUIVIRA.................... 78 57 71 57 / 20 40 50 40
CARRIZOZO....................... 81 60 74 60 / 20 40 50 30
RUIDOSO......................... 74 54 70 54 / 20 50 60 50
CAPULIN......................... 77 53 70 52 / 10 20 30 30
RATON........................... 82 52 76 52 / 10 20 40 30
SPRINGER........................ 83 53 74 54 / 10 30 40 30
LAS VEGAS....................... 78 52 71 52 / 10 40 60 50
CLAYTON......................... 82 59 77 57 / 10 20 30 30
ROY............................. 79 56 73 56 / 10 30 40 50
CONCHAS......................... 82 62 78 62 / 20 40 40 50
SANTA ROSA...................... 80 61 74 61 / 20 50 50 50
TUCUMCARI....................... 83 63 80 62 / 20 30 40 40
CLOVIS.......................... 77 62 76 61 / 40 40 50 50
PORTALES........................ 78 62 77 62 / 40 40 50 50
FORT SUMNER..................... 81 62 75 62 / 20 50 50 50
ROSWELL......................... 80 65 78 64 / 20 50 60 50
PICACHO......................... 77 59 71 60 / 20 50 60 50
ELK............................. 73 56 68 57 / 30 50 60 60
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
41
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1128 PM MDT FRI SEP 19 2014
.AVIATION...
06Z TAF CYCLE
IFR CIGS WORKING INTO THE EASTERN PLAINS OVERNIGHT AND IN TAFS FOR
TCC...ROW...AND LVS. RIDGE BUILDING NORTHWARD ACROSS NM IN THE
WAKE OF ODILE...AS SURFACE LOW OVER NORTHERN MEXICO IMPARTS
EASTERLY COMPONENTS TO SURFACE WINDS THROUGH THE DAY ON SATURDAY.
GUSTS SQUIRTING THROUGH CENTRAL MT CHAIN GAPS OVER THE RIO GRANDE
VALLEY REFLECTED IN G30KT WINDS AT ABQ AND SAF FROM 01Z ONWARD SAT
EVENING. NEXT APPROACHING SYSTEM OVER CENTRAL CALIFORNIA WILL
SUPPORT SOME ISOLATED SHOWERS DRIFTING INTO WESTERN NEW MEXICO AND
IN TAFS FOR GUP AND FMN. OVERNIGHT MT OBSCURATION OVER THE
NORTHERN MTS AND ACROSS THE SOUTHERN TIER LATE SAT NIGHT.
SHY
&&
.PREV DISCUSSION...743 PM MDT FRI SEP 19 2014...
.UPDATE...
UPDATED FORECAST TO LOWER PRECIPITATION CHANCES OVERNIGHT. MODELS CONTINUE
TO GENERATE LOTS OF QPF BUT SATELLITE AND RADAR IMAGERY INDICATING
NOT MUCH MORE THAN A FEW SHOWERS AND STORMS REMAIN OVER SERN NM.
INTERESTINGLY...A SMALL CLUSTER OF CONVECTION OVER THE SOUTHERN
SAN JUAN MOUNTAINS IN COLORADO CONTINUES TO DRIFT SWED TOWARD
THE CHAMA AREA. LEFT IN ISOLATED STORMS THROUGH THE EVENING
ALONG/NEAR THE COLORADO BORDER IN NORTH-CENTRAL NM AS A RESULT.
33
&&
.PREV DISCUSSION...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 AREA WIDE.
&&
.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...UP SLOPE
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 AREA WIDE...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 AREA WIDE 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
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
303 AM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING DRY WEATHER TO THE NORTH
COUNTRY TONIGHT...BUT TEMPERATURES WILL NOT BE AS COLD AS LAST
NIGHT. LOOKING FOR WARMER...WINDIER...AND WETTER CONDITIONS THIS
WEEKEND. HIGHS SATURDAY AND SUNDAY WILL BE IN THE 60S TO LOWER
70S. WINDS WILL BE INCREASING DURING THE DAY ON SATURDAY WITH
GUSTS IN THE 30 TO 40 MPH RANGE. EVENTUALLY RAIN WILL MOVE IN LATE
SATURDAY NIGHT AND ESPECIALLY THROUGHOUT THE DAY ON SUNDAY WITH
WIDESPREAD RAIN EXPECTED SUNDAY AFTERNOON AND NIGHT.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1027 PM EDT FRIDAY...MINOR ADJUSTMENTS TO HOURLY T/TD DATA
AS OF THE 10 O`CLOCK HOUR TO ACCOUNT FOR CURRENT OBSERVATIONAL
TRENDS. SOUTHERLY RETURN FLOW HAS COMMENCED WITH SOME
AREAS...PARTICULARLY THE CHAMPLAIN AND ST LAWRENCE VALLEYS HAVING
LIKELY ALREADY EXPERIENCED THEIR OVERNIGHT LOWS AS READINGS SLOWLY
CLIMB OVERNIGHT. OTHER AREAS HAVE DECOUPLED SO MORE OF A TYPICAL
DIURNAL TREND EXPECTED...NAMELY ERN VT AND PORTIONS OF THE
ADIRONDACKS. CASE IN POINT TRUSTY SARANAC LAKE ALREADY AT THE
FREEZING MARK. HAVE A GREAT NIGHT. PRIOR DISCUSSION FOLLOWS...
PRIOR DISCUSSION...
FORECAST REMAINS IN GOOD SHAPE AS WE PROGRESS INTO THE EVENING
HOURS. CLEAR SKIES WILL GRADUALLY GIVE WAY TO SOME HIGH CLOUDS
(ESPECIALLY NORTH) OVERNIGHT AS SURFACE HIGH PRESSURE SLIDES
OFFSHORE AS SOUTH/SOUTHWESTERLY RETURN FLOW BEGINS IN EARNEST
ALOFT...NOT AS MUCH AT THE SURFACE. NONETHELESS READINGS WILL BE
MILDER TONIGHT THAN LAST NIGHT GIVEN WARM THERMAL RESPONSE THROUGH
THE 925-850 MB LEVEL. STUCK CLOSE TO LATEST RAP 500 MB RH PROGS
WHICH APPEARS TO BE HANDLING THICKER MID LEVEL CLOUDS OFF TO OUR
NORTH...AND ITS SUBSEQUENT PROGRESSION RATHER WELL THIS EVENING.
LOWS REMAIN ON TRACK...RANGING FROM THE MID TO UPPER 30S IN ERN
VT...UPPER 30S TO LOWER 40S DACKS...AND SOLIDLY IN THE 40S FOR THE
CHAMPLAIN AND ST LAWRENCE VALLEYS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/...
AS OF 336 PM EDT FRIDAY...PRESSURE GRADIENT WILL CONTINUE TO
STRENGTHEN FROM THE SOUTH AND SOUTHWEST DURING THE DAY ON
SATURDAY. WHILE THIS WILL PROMOTE LOW LEVEL WARM AIR
ADVECTION...BREEZY TO WINDY CONDITIONS WILL DEVELOP. SO WHILE
HIGHS WILL BE IN THE MID 60S TO THE LOWER 70S...THE WINDS WILL NOT
ALLOW FOR IT TO FEEL THAT WARM WITH GUSTS IN THE 25 TO 35 MPH
RANGE AND EVEN SOME 40 MPH GUSTS IN THE SAINT LAWRENCE VALLEY. DRY
WEATHER IS EXPECTED DURING THE DAY ON SATURDAY...BUT THAT WILL
CHANGE AS AN UPPER LEVEL TROUGH OF LOW PRESSURE DEVELOPS OVER THE
UPPER MIDWEST. THIS FEATURE WILL BEGIN TO SHARPEN UP SATURDAY
NIGHT WHICH WILL ULTIMATELY SLOW THE ONSET OF THE PRECIPITATION
DOWN. CAN SEE A CHANCE OF SHOWERS LATE SATURDAY NIGHT OVER
NORTHERN NEW YORK...BUT THE STEADIER AND MORE WIDESPREAD SHOWERS
WILL NOT MOVE INTO THE ENTIRE AREA UNTIL LATER SUNDAY MORNING
THROUGH SUNDAY NIGHT. THE CLOUDS AND GUSTY WINDS SATURDAY NIGHT
WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL...SO IT WILL NOT TAKE
MUCH ON SUNDAY FOR HIGHS TO GET RIGHT BACK INTO THE MID 60S TO
LOWER 70S. THE UPPER TROUGH WILL BE SLOW TO MOVE EAST OF THE AREA
SUNDAY NIGHT...SO SHOWERS SHOULD BE FAIRLY WIDESPREAD SUNDAY
EVENING BEFORE GRADUALLY TAPERING OFF AFTER MIDNIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 301 AM EDT SATURDAY...A SIGNIFICANT PATTERN CHANGE IS
EXPECTED DURING THE LONG-TERM PERIOD WITH A TREND TOWARD TRANQUIL
WEATHER WITH TEMPERATURES ABOVE SEASONAL AVERAGES. GOOD RUN-TO-RUN
CONSISTENCY CONTINUES TO BE OBSERVED IN THE 00Z OPERATIONAL GFS
AND ECMWF.
A LINGERING MID-LEVEL TROUGH/CYCLONIC FLOW EARLY IN THE PERIOD WILL
BRING PARTLY TO MOSTLY CLOUDY CONDITIONS WITH A SLIGHT CHANCE OF A
RAIN SHOWER MONDAY NIGHT INTO TUESDAY. THE HIGHEST POPS (~25%) ARE
ACROSS THE NORTHERN MOUNTAINS DURING THE DAY TUESDAY...WITH
DEVELOPMENT OF WEAK DAYTIME INSTABILITY. ANY PRECIPITATION WILL BE
LIGHT. THEREAFTER...AN AMPLIFYING DEEP-LAYER RIDGE BUILDS EWD
FROM THE MIDWEST AND GREAT LAKES PROVIDING GENERALLY CLEAR SKIES.
WILL SEE HIGHS IN THE MID 60S WEDNESDAY...AND THEN INTO THE LOW-
MID 70S IN THE VALLEYS ON THURSDAY AND FRIDAY AS AIR MASS
MODERATES. RELATIVELY LIGHT WINDS ARE EXPECTED AS WELL. CLEAR
SKIES/LIGHT WINDS WILL LEAD TO SOME LOCAL NOCTURNAL FOG IN THE
FAVORED RIVER VALLEYS EACH NIGHT FROM TUESDAY NIGHT THROUGH
THURSDAY NIGHT. COLDEST LOW TEMPERATURES WILL BE TUESDAY
NIGHT...GENERALLY IN THE UPPER 30S TO LOWER 40S. THEREAFTER...LOWS
WILL GENERALLY BE IN THE MID-UPPER 40S IN MOST SECTIONS.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD...THOUGH THERE WILL BE AN INCREASE IN MID-UPPER LEVEL
CLOUDS THROUGH THE DAYLIGHT HOURS AREAWIDE. ALSO WATCHING SOME
DEVELOPING STRATUS ACROSS E-CENTRAL NY...WHICH WILL IMPACT RUT/MPV
AT TIMES THIS MORNING WITH SCT-BKN040-050. NO PRECIPITATION IS
EXPECTED THROUGH THE PERIOD. WINDS WILL BE INCREASING FROM THE
SOUTH TO SOUTHWEST...ESPECIALLY DURING THE DAYLIGHT HOURS WITH
INCREASING PRESSURE GRADIENT. AT BTV...WINDS ALREADY 10KTS AND
WILL INCREASE TO 15G25KT AFTER 13-14Z. WILL ALSO BE DEALING WITH
LOW-LEVEL WIND SHEAR AT PBG/MSS/SLK UNTIL LOW-LEVELS MIX OUT AFTER
12Z THIS MORNING. INCLUDED LLWS IN THE TAFS AT ABOVE MENTIONED
TAF SITES THIS MORNING...WITH STRONGEST SHEAR BETWEEN 1.5-2 KFT
AGL.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...FRONTAL SYSTEM MOVING IN
FROM THE WEST WILL BRING POTENTIAL FOR WIDELY SCATTERED RAIN
SHOWERS DURING THE DAY SUNDAY...WITH PERIODS OF MVFR CEILINGS AND
VSBYS. UPPER TROUGH REMAINS IN PLACE WITH POTENTIAL FOR SCATTERED
SHOWERS SUNDAY NIGHT INTO MONDAY. MAY SEE SOME PERIODS OF
CONTINUING MVFR CEILINGS DURING SUN NIGHT AND MONDAY. GENERALLY
TRENDING VFR MONDAY NIGHT ONWARD WITH DEVELOPING STRONG SURFACE
AND UPPER RIDGE BY MID-WEEK ACROSS THE GREAT LAKES AND NEW
ENGLAND.
&&
.MARINE...
STRONG SOUTH TO SOUTHWEST WINDS WILL DEVELOP AFTER MIDNIGHT TONIGHT AND
CONTINUE RIGHT INTO SUNDAY MORNING. SPEEDS WILL INCREASE INTO THE
20 TO 30 KNOT RANGE DURING THIS TIME PERIOD WITH GUSTS AS HIGH AS
35 KNOTS SATURDAY NIGHT AND SUNDAY MORNING. WAVES WILL BUILD INTO
THE 2 TO 5 FOOT RANGE MAKING FOR ROUGH BOATING CONDITIONS FOR A
GOOD PART OF THE WEEKEND. AS A RESULT...A LAKE WIND ADVISORY IS IN
EFFECT FROM MIDNIGHT TONIGHT RIGHT THROUGH SUNDAY MORNING.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...JMG
SHORT TERM...EVENSON
LONG TERM...BANACOS
AVIATION...BANACOS
MARINE...EVENSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
137 AM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING DRY WEATHER TO THE NORTH
COUNTRY TONIGHT...BUT TEMPERATURES WILL NOT BE AS COLD AS LAST
NIGHT. LOOKING FOR WARMER...WINDIER...AND WETTER CONDITIONS THIS
WEEKEND. HIGHS SATURDAY AND SUNDAY WILL BE IN THE 60S TO LOWER
70S. WINDS WILL BE INCREASING DURING THE DAY ON SATURDAY WITH
GUSTS IN THE 30 TO 40 MPH RANGE. EVENTUALLY RAIN WILL MOVE IN LATE
SATURDAY NIGHT AND ESPECIALLY THROUGHOUT THE DAY ON SUNDAY WITH
WIDESPREAD RAIN EXPECTED SUNDAY AFTERNOON AND NIGHT.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1027 PM EDT FRIDAY...MINOR ADJUSTMENTS TO HOURLY T/TD DATA
AS OF THE 10 O`CLOCK HOUR TO ACCOUNT FOR CURRENT OBSERVATIONAL
TRENDS. SOUTHERLY RETURN FLOW HAS COMMENCED WITH SOME
AREAS...PARTICULARLY THE CHAMPLAIN AND ST LAWRENCE VALLEYS HAVING
LIKELY ALREADY EXPERIENCED THEIR OVERNIGHT LOWS AS READINGS SLOWLY
CLIMB OVERNIGHT. OTHER AREAS HAVE DECOUPLED SO MORE OF A TYPICAL
DIURNAL TREND EXPECTED...NAMELY ERN VT AND PORTIONS OF THE
ADIRONDACKS. CASE IN POINT TRUSTY SARANAC LAKE ALREADY AT THE
FREEZING MARK. HAVE A GREAT NIGHT. PRIOR DISCUSSION FOLLOWS...
PRIOR DISCUSSION...
FORECAST REMAINS IN GOOD SHAPE AS WE PROGRESS INTO THE EVENING
HOURS. CLEAR SKIES WILL GRADUALLY GIVE WAY TO SOME HIGH CLOUDS
(ESPECIALLY NORTH) OVERNIGHT AS SURFACE HIGH PRESSURE SLIDES
OFFSHORE AS SOUTH/SOUTHWESTERLY RETURN FLOW BEGINS IN EARNEST
ALOFT...NOT AS MUCH AT THE SURFACE. NONETHELESS READINGS WILL BE
MILDER TONIGHT THAN LAST NIGHT GIVEN WARM THERMAL RESPONSE THROUGH
THE 925-850 MB LEVEL. STUCK CLOSE TO LATEST RAP 500 MB RH PROGS
WHICH APPEARS TO BE HANDLING THICKER MID LEVEL CLOUDS OFF TO OUR
NORTH...AND ITS SUBSEQUENT PROGRESSION RATHER WELL THIS EVENING.
LOWS REMAIN ON TRACK...RANGING FROM THE MID TO UPPER 30S IN ERN
VT...UPPER 30S TO LOWER 40S DACKS...AND SOLIDLY IN THE 40S FOR THE
CHAMPLAIN AND ST LAWRENCE VALLEYS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 336 PM EDT FRIDAY...PRESSURE GRADIENT WILL CONTINUE TO
STRENGTHEN FROM THE SOUTH AND SOUTHWEST DURING THE DAY ON
SATURDAY. WHILE THIS WILL PROMOTE LOW LEVEL WARM AIR
ADVECTION...BREEZY TO WINDY CONDITIONS WILL DEVELOP. SO WHILE
HIGHS WILL BE IN THE MID 60S TO THE LOWER 70S...THE WINDS WILL NOT
ALLOW FOR IT TO FEEL THAT WARM WITH GUSTS IN THE 25 TO 35 MPH
RANGE AND EVEN SOME 40 MPH GUSTS IN THE SAINT LAWRENCE VALLEY. DRY
WEATHER IS EXPECTED DURING THE DAY ON SATURDAY...BUT THAT WILL
CHANGE AS AN UPPER LEVEL TROUGH OF LOW PRESSURE DEVELOPS OVER THE
UPPER MIDWEST. THIS FEATURE WILL BEGIN TO SHARPEN UP SATURDAY
NIGHT WHICH WILL ULTIMATELY SLOW THE ONSET OF THE PRECIPITATION
DOWN. CAN SEE A CHANCE OF SHOWERS LATE SATURDAY NIGHT OVER
NORTHERN NEW YORK...BUT THE STEADIER AND MORE WIDESPREAD SHOWERS
WILL NOT MOVE INTO THE ENTIRE AREA UNTIL LATER SUNDAY MORNING
THROUGH SUNDAY NIGHT. THE CLOUDS AND GUSTY WINDS SATURDAY NIGHT
WILL KEEP LOW TEMPERATURES WELL ABOVE NORMAL...SO IT WILL NOT TAKE
MUCH ON SUNDAY FOR HIGHS TO GET RIGHT BACK INTO THE MID 60S TO
LOWER 70S. THE UPPER TROUGH WILL BE SLOW TO MOVE EAST OF THE AREA
SUNDAY NIGHT...SO SHOWERS SHOULD BE FAIRLY WIDESPREAD SUNDAY
EVENING BEFORE GRADUALLY TAPERING OFF AFTER MIDNIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 336 PM EDT FRIDAY...NORTHWEST FLOW ALOFT WILL EXIST OVER THE
AREA MONDAY AND TUESDAY. THERE MAY BE SOME LINGERING SHOWERS
MONDAY MORNING...ESPECIALLY OVER VERMONT...BUT DRIER WEATHER IS
EXPECTED TO DEVELOP MONDAY AFTERNOON THROUGH TUESDAY. THE
NORTHWEST FLOW ALOFT WILL RESULT IN BELOW NORMAL HIGH
TEMPERATURES. LARGE UPPER LEVEL RIDGE BUILDS INTO THE REGION
WEDNESDAY THROUGH FRIDAY. THIS WILL RESULT IN A WARMING TREND WITH
HIGH TEMPERATURES AT OR ABOVE SEASONAL NORMALS THURSDAY AND
FRIDAY. DRY WEATHER WILL ALSO EXIST WEDNESDAY THROUGH FRIDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE
PERIOD...THOUGH THERE WILL BE AN INCREASE IN MID-UPPER LEVEL
CLOUDS THROUGH THE DAYLIGHT HOURS AREAWIDE. ALSO WATCHING SOME
DEVELOPING STRATUS ACROSS E-CENTRAL NY...WHICH WILL IMPACT RUT/MPV
AT TIMES THIS MORNING WITH SCT-BKN040-050. NO PRECIPITATION IS
EXPECTED THROUGH THE PERIOD. WINDS WILL BE INCREASING FROM THE
SOUTH TO SOUTHWEST...ESPECIALLY DURING THE DAYLIGHT HOURS WITH
INCREASING PRESSURE GRADIENT. AT BTV...WINDS ALREADY 10KTS AND
WILL INCREASE TO 15G25KT AFTER 13-14Z. WILL ALSO BE DEALING WITH
LOW-LEVEL WIND SHEAR AT PBG/MSS/SLK UNTIL LOW-LEVELS MIX OUT AFTER
12Z THIS MORNING. INCLUDED LLWS IN THE TAFS AT ABOVE MENTIONED
TAF SITES THIS MORNING...WITH STRONGEST SHEAR BETWEEN 1.5-2 KFT
AGL.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...FRONTAL SYSTEM MOVING IN
FROM THE WEST WILL BRING POTENTIAL FOR WIDELY SCATTERED RAIN
SHOWERS DURING THE DAY SUNDAY...WITH PERIODS OF MVFR CEILINGS AND
VSBYS. UPPER TROUGH REMAINS IN PLACE WITH POTENTIAL FOR SCATTERED
SHOWERS SUNDAY NIGHT INTO MONDAY. MAY SEE SOME PERIODS OF
CONTINUING MVFR CEILINGS DURING SUN NIGHT AND MONDAY. GENERALLY
TRENDING VFR MONDAY NIGHT ONWARD WITH DEVELOPING STRONG SURFACE
AND UPPER RIDGE BY MID-WEEK ACROSS THE GREAT LAKES AND NEW
ENGLAND.
&&
.MARINE...
STRONG SOUTH TO SOUTHWEST WINDS WILL DEVELOP AFTER MIDNIGHT TONIGHT AND
CONTINUE RIGHT INTO SUNDAY MORNING. SPEEDS WILL INCREASE INTO THE
20 TO 30 KNOT RANGE DURING THIS TIME PERIOD WITH GUSTS AS HIGH AS
35 KNOTS SATURDAY NIGHT AND SUNDAY MORNING. WAVES WILL BUILD INTO
THE 2 TO 5 FOOT RANGE MAKING FOR ROUGH BOATING CONDITIONS FOR A
GOOD PART OF THE WEEKEND. AS A RESULT...A LAKE WIND ADVISORY IS IN
EFFECT FROM MIDNIGHT TONIGHT RIGHT THROUGH SUNDAY MORNING.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...JMG
SHORT TERM...EVENSON
LONG TERM...EVENSON
AVIATION...BANACOS
MARINE...EVENSON
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
547 AM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE WILL RIDGE INTO THE REGION FROM THE NORTH TODAY. LOW
PRESSURE WILL MOVE NORTHEAST SUNDAY JUST OFF THE COAST. A COLD
FRONT WILL MOVE THROUGH MONDAY. HIGH PRESSURE BEHIND THE FRONT
WILL PASS BY TO THE NORTH TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 230 AM SAT...1030 MB HIGH PRES CENTERED OVER NEW ENGLAND
CONTINUES TO RIDGE SWWD INTO THE REGION WHILE AN INVERTED TROUGH
OVER THE OFFSHORE WATERS IS ADVANCING TOWARD THE COAST AND A 1014
MB LOW PRES IS DEVELOPING OFF THE EAST COAST OF FL. MEANWHILE A
WEAK UPPER LOW RESIDES OVER THE SOUTHEAST STATES WITH A NORTHERN
STREAM SHORTWAVE TROUGH MOVING INTO THE GREAT LAKES.
THE UPPER TROUGH WILL CONTINUE TO DIG INTO THE MIDWEST AND GREAT
LAKES THROUGH THE PERIOD AND WILL BEGIN TO ABSORB THE UPPER LOW
OVER THE SOUTHEAST WHICH IN RESPONSE WILL LIFT THE SFC LOW NORTH
JUST OFF THE SOUTHEAST COAST. EXPECT THE COASTAL TROUGH TO MOVE
INTO EASTERN SECTIONS TODAY THEN GRADUALLY DISSIPATE WHILE THE SFC
LOW LIFTS NORTH TO OFF THE SC COAST BY LATE IN THE PERIOD.
A FEW SHOWERS SHOWING UP ON RADAR ACROSS THE COASTAL WATERS ASSOC
WITH THE COASTAL TROUGH AND EXPECT THESE TO CONTINUE TO ADVANCE
TOWARD THE COAST THROUGH THE MORNING. THE BEST CHANCE OF
SHOWERS...AND POSSIBLY AN ISOLATED THUNDERSTORM...WILL OCCUR
ACROSS EASTERN SECTIONS TODAY AS THE SHOWERS WILL TEND TO
DISSIPATE AS THEY MOVE INTO A DRIER AIRMASS RIDGING IN FROM THE
NORTH. IN ADDITION...COULD SEE SOME SHOWERS ASSOC WITH THE LOW TO
THE SOUTH LIFTING TOWARD THE REGION BY LATE AFTERNOON...MAINLY
AFFECTING THE CRYSTAL COAST. MOSTLY CLOUDY SKIES EXPECTED EASTERN
SECTIONS WITH VARIABLY CLOUDY SKIES TO THE WEST. HIGHS TODAY WILL
REACH A COUPLE DEGREES EITHER SIDE OF 80.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 230 AM SAT...THE SFC LOW WILL CONTINUE TO LIFT NORTH ALONG
THE COAST TONIGHT AND MODELS IN FAIRLY CLOSE AGREEMENT WITH THE
LOW POSITIONED SE OF CAPE LOOKOUT BY 12Z SUN. SLIGHTLY IMPROVING
UPPER LEVEL SUPPORT WITH A STRENGTHENING JET STREAK JUST TO THE
NORTH COUPLED WITH LOW LEVEL CONVERGENCE NEAR THE COASTAL TROUGH
AND SFC LOW WILL BRING A DESCENT CHANCE OF SHOWERS ACROSS EASTERN
SECTIONS TONIGHT. THERE WILL LIKELY BE A SHARP GRADIENT OF PCPN
ACROSS THE REGION WITH BEST CHANCES EAST OF HIGHWAY 17 WHERE
FORCING WILL BE MORE FAVORABLE AND MOISTURE WILL BE GREATER.
MODELS NOT IN BEST AGREEMENT WITH PRECIP AMOUNTS BUT COULD SEE AS
MUCH AS 1/2 TO 1" ALONG THE IMMEDIATE COAST FROM AROUND CAPE
LOOKOUT TO OREGON INLET BUT THEN TAPER OFF RATHER QUICKLY WEST OF
A LINE FROM JACKSONVILLE TO NEW BERN TO COLUMBIA. LOWS EXPECTED IN
THE MID 60S WELL INLAND TO LOWER 70S ALONG THE COAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 232 AM SAT...ACTIVE PATTERN THROUGH THE FIRST PART OF THE LONG
TERM PERIOD. MODELS AGREE THAT CUT OFF UPPER LOW OVER THE FL/GA AREA
WILL MOVE UP THE COAST AS IT DEEPENS. ACCOMPANYING SURFACE LOW WILL
SKIRT THE COAST...AND IS EXPECTED TO BE ALONG THE NORTH CAROLINA
COAST SUNDAY MORNING. UPPER LEVEL ENERGY WILL BE CENTERED
OFFSHORE...THIS WILL HELP KEEP HIGH CHANCES OF PRECIPITATION
CONFINED MAINLY TO COASTAL SECTIONS. INSTABILITY LIMITED BUT CANT
COMPLETELY RULE OUT THUNDERSTORMS. PWS JUST BELOW 2 INCHES SUNDAY
MORNING...BUT QUICKLY DROPS OFF AS SYSTEM MOVES AWAY. AS SYSTEM
LIFTS NORTH OF THE AREA DURING THE DAY SUNDAY...UPPER FLOW WILL
BRIEFLY BECOME ZONAL AHEAD OF NEXT APPROACHING TROUGH.
THIS NEXT SYSTEM WILL PUSH A FRONT AHEAD OF IT THROUGH EASTERN NORTH
CAROLINA EARLY MONDAY. NOT AN AWFUL LOT OF MOISTURE EVIDENT IN THE
MODELS WITH THIS BOUNDARY...AND UPPER LEVEL ENERGY LAGS BEHIND
IT...SO WILL KEEP PRECIPITATION CHANCES LOW. HIGH PRESSURE WILL
QUICKLY BUILD IN BEHIND THE FRONT MONDAY NIGHT. HOWEVER MODELS
DIFFER A BIT AT THIS TIME PERIOD IN THE UPPER LEVEL PATTERN WITH
ECMWF DIGGING A DEEPER UPPER LEVEL TROUGH DOWN THE EAST COAST AND
THE GFSENS BEING NOT AS DEEP. THIS DOESNT APPEAR TO AFFECT THE
SURFACE PATTERN AS MODELS AGREE ON HIGH PRESSURE NORTH OF THE AREA
THROUGH THE REMAINDER OF THE WEEK. MODELS DO HINT AT A WEAK INVERTED
TROUGH ALONG THE COAST LATE IN THE WEEK. CURRENT GRIDS HAVE LOW POPS
AND WILL CONTINUE THAT TREND.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 230 AM SAT...PRED VFR EXPECTED THROUGH THE TAF PERIOD.
CLOUDS AND LIGHT MIXING PREVENTING FOG DEVELOPMENT THIS MORNING
BUT CANNOT RULE OUT BRIEF PERIODS OF MVFR VSBYS AT PGV WHERE SKIES
HAVE REMAINED CLEAR...DEWPOINT DEPRESSION HAVE BEEN LOW AND
DECOUPLING HAS OCCURRED AT TIMES. A COASTAL TROUGH WILL MOVE INTO
EASTERN NC TODAY WITH SFC LOW PRES LIFTING NORTH ALONG THE SE
COAST AND EXPECT VARIABLY CLOUDY SKIES WITH GREATEST COVERAGE
EASTERN SECTIONS. COULD SEE AN ISOLATED SHOWER TODAY AS THE
COASTAL TROUGH MOVES INLAND BUT BETTER CHANCE OF SHOWERS WILL
OCCUR TONIGHT AS THE LOW LIFTS NE JUST OFF THE COAST. COASTAL
SITES WILL HAVE THE BETTER CHANCE OF RECEIVING PRECIP WHILE PGV
AND ISO COULD VERY WELL REMAIN DRY. IF HEAVIER PRECIP DEVELOPS
COULD SEE BRIEF REDUCTIONS IN CIGS/VSBYS TO MVFR OR POSSIBLY IFR.
NE FLOW WILL CONTINUE TODAY WITH GUSTS TO AROUND 15 KT POSSIBLE
THIS AFTERNOON.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 AM SAT...LOW PRESSURE WILL MOVE UP THE COAST THIS
WEEKEND...AND BE OFF THE NORTH CAROLINA COAST BY SUNDAY MORNING.
WILL HAVE SOME MVFR CIGS/VIS SUNDAY IN ASSOCIATED SHOWERS AND LOW
CLOUDS. THIS SYSTEM WILL MOVE AWAY FROM THE AREA LATE SUNDAY AS
ANOTHER SYSTEM APPROACHES FROM THE WEST. NOT TOO MUCH MOISTURE
ASSOCIATED WITH THIS FRONTAL BOUNDARY AND UPPER LEVEL ENERGY STAYS
WEST AS IT MOVES THROUGH EASTERN NORTH CAROLINA MONDAY MORNING. MAY
HAVE ISOLATED MVFR CIGS/VIS IN ANY SHOWERS THAT DEVELOP. HIGH
PRESSURE BUILDS IN BEHIND THE FRONT WITH MAINLY VFR CONDITIONS
EXPECTED MONDAY NIGHT THROUGH WEDNESDAY...HOWEVER MAY HAVE SUB VFR
CONDITIONS IN THE PREDAWN HOURS WITH NORTHEASTERLY FLOW.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 530 AM SAT...EXTENDED THE SCA FOR THE PAMLICO SOUND AND
WATERS SOUTH OF OCRACOKE INLET UNTIL 15Z AS OBS CONTINUE TO SHOW
FREQUENT GUSTS TO 25 KT AND SEAS UP TO 6 FT ACROSS THE COASTAL
WATERS. MOST MODELS STILL TOO QUICK TO BRING DOWN WINDS/SEAS EARLY
THIS MORNING. BLENDED HEAVILY WITH THE RUC FOR WINDS WHICH IS MUCH
STRONGER...AND PERHAPS TOO STRONG...THAN ANY OTHER MODEL BETWEEN
12-18Z...BUT SEEMS TO CAPTURE THE CURRENT CONDITIONS BETTER. IF
THE RUC DOES VERIFY LATER THIS MORNING AN EXPANSION OF TIME AND
AREA FOR THE SCA WILL BE NECESSARY.
PREVIOUS DISCUSSION...STRONG SFC HIGH PRES CONTINUES TO RIDGE
INTO THE REGION EARLY THIS MORNING BRINGING NE FLOW AROUND 10-20
KT WITH MANY AREAS SOUTH OF OREGON INLET SEEING FREQUENT GUSTS TO
AROUND 25 KT. EXPECT WINDS TO GRADUALLY DIMINISH TO AROUND 10-15
KT BY THIS AFTERNOON AS A COASTAL TROUGH MOVES INTO THE REGION
ALLOWING GRADIENTS TO WEAKEN SOME. GRADIENTS EXPECTED TO TIGHTEN
AGAIN TONIGHT...MAINLY AFTER MIDNIGHT...AS THE SFC LOW LIFTS TO
JUST OFF CAPE FEAR BY LATE TONIGHT BRINGING WINDS TO 10-20 KT AND
POSSIBLY GUSTS TO AROUND 25 KT. SEAS REMAIN TRICKY AS MODELS A
FOOT OR TWO UNDERDONE THIS PAST EVENING AND HAVE BEEN TOO QUICK TO
DISSIPATE. SEAS CURRENTLY 4-6 FT AND ARE EXPECTED TO SUBSIDE TO
BELOW SCA CRITERIA SOUTH OF OREGON INLET THIS MORNING AS GRADIENTS
WEAKEN SOME...HOWEVER THE PROLONGED NE FETCH OF WINDS ARE EXPECTED
TO KEEP SEAS ELEVATED UP TO 5-7 FT NORTH OF OREGON INLET THROUGH
THE SHORT TERM. MODELS ALSO INDICATING SEAS REBUILD UP TO 6 FT
SOUTH OF OCRACOKE INLET AFTER MIDNIGHT TONIGHT WITH GRADIENTS
TIGHTENING NEAR THE LOW LIFTING TOWARD THE REGION.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 252 AM SAT...SURFACE WIND WILL BE VARIABLE SUNDAY MORNING AS
LOW PRESSURE MOVES UP THE COAST AND ACROSS THE NORTH CAROLINA
COASTAL WATERS. AM EXPECTING THE LOW PRESSURE TO REMAIN JUST EAST OF
THE WATERS WITH NORTH NORTH WESTERLY FLOW. SPEEDS WILL BE 20 TO 25
KNOTS . IF LOW TRACKS FURTHER WEST...SPEEDS WILL BE LIGHT AND
DIRECTION WILL BE DEPENDENT ON WHERE THE LOW TRACKS. SEA HEIGHTS
WILL REACH SMALL CRAFT ADVISORY CRITERIA OVER MOST OF THE WATERS
WITH UP TO 8 FEET EXPECTED IN THE OUTER WATERS. AS THE LOW MOVES
AWAY FROM THE AREA LATE SUNDAY...WIND SPEED AND SEAS WILL DECREASE
BELOW SMALL CRAFT ADVISORY CRITERIA. DIRECTION WILL TURN
SOUTHWESTERLY SUNDAY NIGHT AHEAD OF NEXT APPROACHING SYSTEM. THIS
FRONT IS EXPECTED TO PASS THROUGH THE WATERS MONDAY AFTERNOON WITH
WIND BECOMING NORTH AND NORTHEASTERLY BEHIND IT AS HIGH PRESSURE
BUILDS IN. GRADIENT BETWEEN THE DEPARTING LOW PRESSURE AND BUILDING
HIGH PRESSURE WILL INCREASE WINDS TO 15 TO 20 KNOTS MONDAY NIGHT
THROUGH WEDNESDAY. MODELS HINTING AS A TROUGH DEVELOPING ALONG THE
COAST LATE WEDNESDAY...WHICH WILL HELP INCREASE WIND SPEEDS
WEDNESDAY NIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ135-
156-158.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...CGG
AVIATION...CGG/SK
MARINE...CGG/SK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
105 AM CDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 105 AM CDT SAT SEP 20 2014
THE INHERITED FORECAST IS MAINLY ON TRACK FOR THE EARLY MORNING
FORECAST UPDATE. DID MODIFY POPS FOR THE NEXT S/WV SET TO MOVE
THROUGH THE NORTHERN PLAINS THIS MORNING. SCALED BACK ON
PRECIPITATION CHANCES TILL 09Z...HIGHER POPS ACROSS THE NORTH
DURING THE MORNING HOURS LATE TONIGHT PAST DAYBREAK SATURDAY.
UPDATE ISSUED AT 952 PM CDT FRI SEP 19 2014
CONVECTION HAS ALL BUT ENDED ACROSS WESTERN AND CENTRAL NORTH
DAKOTA WITH THE SETTING SUN. STILL AN ISOLATED SHOWER ALONG THE
MISSOURI RIVER BORDERING MONTANA...BUT THIS ACTIVITY HAS BEEN
DECREASING AND EXPECT THIS TO CONTINUE. THUS HAVE REMOVED POPS FOR
THIS EVENING. MODELS SUGGEST NEXT WAVE WILL BE MOVING INTO
SOUTHEAST SASKATCHEWAN LATE TONIGHT AND HAVE UTILIZED THE 01 UTC
RAP AS A GUIDE FOR TIMING OF THE PRECIPITATION WITH THIS WAVE.
BROUGHT SHOWERS INTO THE FAR NORTHWEST AROUND 09-10 UTC WITH
SHOWERS AND ISOLATED THUNDERSTORMS GENERALLY ALONG AND NORTH OF A
LINE FROM WILLISTON TO GARRISON TO JAMESTOWN ON SATURDAY...WITH
PRECIPITATION ENDING IN THE SOUTHERN JAMES RIVER VALLEY BY MID TO
LATE AFTERNOON.
UPDATE ISSUED AT 642 PM CDT FRI SEP 19 2014
ISOLATED THUNDERSTORMS CONTINUE TO TRACK SOUTHEAST ACROSS
BOTTINEAU AND MCHENRY COUNTIES IN NORTH CENTRAL NORTH
DAKOTA. STRONGER CELLS HAVE REMAINED OVER NORTHEAST NORTH DAKOTA
NEAR THE SURFACE LOW PRESSURE SYSTEM. GUSTY NORTHWEST WINDS BEHIND
THE LOW SHOULD DIMINISH EARLY THIS EVENING ACROSS THE WEST AND
CENTRAL. UPDATED SKY COVER AND POP GRIDS BASED ON LATEST RADAR AND
SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT UPDATES NEEDED.
&&
.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 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 105 AM CDT SAT SEP 20 2014
VFR CONDITIONS EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE 06Z TAF PERIOD. SCATTERED VFR CLOUDINESS THROUGH
SATURDAY MORNING THROUGH EARLY AFTERNOON...BASES AROUND 7-10KFT
TRACKING MAINLY FROM KMOT TO KJMS AS ANOTHER QUICK MOVING SYSTEM
MOVES THROUGH. WILL MENTION A VCSH AT KISN-KMOT-KJMS SATURDAY
MORNING. NORTHWEST FLOW WILL INCREASE AGAIN SATURDAY AFTERNOON
WITH GUSTS TO AROUND 30-35 KTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AYD
LONG TERM...JV
AVIATION...NH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
417 AM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF TO THE EAST TODAY AS A COLD FRONT
APPROACHES FROM THE NORTHWEST. THE COLD FRONT WILL MOVE ACROSS THE
AREA LATE TONIGHT AND SUNDAY. HIGH PRESSURE WILL THEN BECOME
REESTABLISHED FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MODELS...SUCH AS THE HRRR AND RAP...CONTINUE TO FORECAST
THE DEVELOPMENT OF LOWER LEVEL CLOUDS...4 K FT TO 6 KT ACROSS THE
SRN CWFA TOWARD MORNING. THIS DEVELOPMENT IS DUE TO WEAK
ISENTROPIC LIFT OCCURRING AROUND DEPARTING HIGH PRESSURE. THERE
MAY BE ENOUGH SHALLOW INSTABILITY IN THIS DECK TO WARRANT A LOW
CHANCE POP ALONG AND SOUTH OF THE OHIO RIVER THROUGH THE MORNING
HOURS.
OTHERWISE...WE SHOULD SEE PARTLY TO MOSTLY SUNNY SKIES TODAY OUT
AHEAD OF A COLD FRONT WHICH WILL MAKE IN ROADS TOWARD OUR REGION
TONIGHT. INCREASING SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND
THE FRONT WILL BOOST TEMPERATURES INTO THE UPPER 70S TO THE LOWER
80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HAVE AGAIN USED A BLEND OF THE ECMWF/GFS...ALONG WITH CONVECTION
ALLOWING MODELS...TO HONE IN ON THE PROSPECTS OF PCPN TONIGHT INTO
SUNDAY NIGHT.
A SERIES OF S/WVS WILL DIG EAST/SOUTHEAST THROUGH THE GREAT LAKES
TONIGHT INTO SUNDAY NIGHT...WHICH WILL EVENTUALLY ESTABLISH A LONG
WAVE MID LEVEL TROUGH OVER ERN CANADA SOUTHWARD INTO THE ERN U.S.
BY MONDAY MORNING. THE FIRST WAVE...ALONG WITH PREFRONTAL
CONVERGENCE...IS EXPECTED TO RESULT IN SHOWERS/THUNDERSTORMS TO
OUR NORTHWEST LATE THIS AFTERNOON INTO EARLY THIS EVENING. MODELS
CONTINUE TO SUGGEST THAT AS THIS ACTIVITY PROPAGATES SOUTHEAST INTO
OUR AREA TONIGHT OUT AHEAD OF A COLD FRONT...IT WILL UNDERGO A
WEAKENING TREND. RAPIDLY DECREASING INSTABILITY...WEAKENING LOW
LEVEL FORCING...ALONG WITH WEAKENING UPPER LEVEL SUPPORT ARE THE
REASONS THAT THIS IS FORECAST TO OCCUR. AS A RESULT...HAVE PLACED
THE HIGHEST POPS TONIGHT OVER THE FAR NW...DECREASING THE THREAT
TO JUST 30 AND 40 PERCENT THROUGH THE REMAINDER OF THE REGION
TOWARD SUNDAY MORNING.
ON SUNDAY...ANOTHER EMBEDDED S/WV WILL APPROACH FROM THE NORTHWEST
WHILE THE COLD FRONT PUSHES EAST/SOUTHEAST THROUGH THE REGION.
WITH THE FASTER TIMING OF THE GFS/ECMWF...BELIEVE ANY
SHOWER/THUNDERSTORM REDEVELOPMENT SHOULD OCCUR JUST EAST/SOUTHEAST
OF THE AREA. IN THE WAKE OF THE FRONT...AND BEFORE THE ARRIVAL OF
THE NEXT S/WV...WE SHOULD SEE A POCKET OF DRY WEATHER ALONG WITH
PARTLY TO MOSTLY SUNNY SKIES. HIGHS ON SUNDAY WILL BE TRICKY AS
CAA WILL BE ONGOING THROUGH THE DAY. WILL FORECAST LOWER 70S
NORTHWEST TO THE UPPER 70S SOUTHERN/SOUTHEAST.
FOR SUNDAY NIGHT...AFOREMENTIONED S/WV WILL PASS THROUGH THE
REGION ALONG WITH A SFC TROF AXIS. THERE COULD BE ENOUGH
INSTABILITY WITH THIS FEATURE TO BRING A FEW SPOTTY SHOWERS TO THE
NRN ZONES SUNDAY EVENING. BUT AS TIME WEARS ON AND INSTABILITY
WANES...THE THREAT SHOULD RELEGATE ITSELF TO OUR NE TOWARD
CENTRAL/EASTERN LAKE ERIE. PARTLY CLOUD SKIES WILL UNDERGO A
CLEARING TREND...ESPECIALLY WEST OVERNIGHT. LOWS WILL DROP INTO
THE MID 40S NORTHWEST TO THE LOWER 50S SOUTHEAST.
FOR MONDAY INTO MONDAY NIGHT...MID LEVEL TROUGH WILL MOVE EAST AS
A MID LEVEL RIDGE BUILDS NORTHWARD INTO THE MIDDLE AND UPPER MS
RIVER VALLEY. AT THE SURFACE...A SPRAWLING AREA OF HIGH PRESSURE
WILL BE FOUND AS IT SETTLES RIGHT OVER THE OHIO VALLEY BY TUESDAY
MORNING. CLOUDS WILL CONTINUE TO DECREASE THROUGH THE PERIOD WITH
CLEAR SKIES EXPECTED BY MONDAY NIGHT. AFTER COOL TEMPERATURES
RANGING FROM THE LOWER 60S NORTH TO THE UPPER 60S SOUTH...OVERNIGHT
LOWS WILL DIP INTO THE UPPER 30S AND LOWER 40S BY TUESDAY MORNING.
ON TUESDAY...WITH THE HIGH REMAINING IN PLACE...SKIES WILL BE
SUNNY. HIGHS WILL WARM INTO THE UPPER 60S TO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH
THE LONG TERM. TEMPERATURES WILL SLOWLY WARM THROUGH THE LONG
TERM WITH HIGH TEMPERATURES BY FRIDAY EXPECTED TO BE IN THE MID TO
UPPER 70S.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS ARE GENERALLY EXPECTED...BUT WITH A FEW
COMPLICATIONS IN THE FORECAST TO DISCUSS. TRANQUIL CONDITIONS TO
BEGIN THE OVERNIGHT PERIOD WILL GIVE WAY TO INCREASING SOUTHERLY
FLOW BY MORNING...TURNING SOUTHWESTERLY AND GUSTY (UP TO 20 KNOTS)
BY EARLY AFTERNOON. AN INCREASE IN CLOUDS IS EXPECTED GOING INTO
THE DAY...GENERALLY IN THE 4000-6000 FOOT RANGE. MVFR FOG AT KLUK
WILL LIKELY DISSIPATE OVER THE NEXT FEW HOURS...AS WINDS BEGIN TO
INCREASE.
A COLD FRONT WILL APPROACH THE REGION ON SATURDAY NIGHT AND INTO
EARLY SUNDAY MORNING. THE EXTENT OF PRECIPITATION WITH THIS FRONT
IS NOT CERTAIN...BUT IT LOOKS LIKE THE TIMING WILL BRING
A CHANCE OF PRE-FRONTAL PRECIPITATION TO THE TAF SITES BY 05Z-08Z.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE FROM LATE SATURDAY NIGHT
THROUGH SUNDAY AFTERNOON.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
250 AM CDT SAT SEP 20 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT SAT SEP 20 2014
MAIN CONCERNS ARE ON EXITING MORNING CONVECTION AND THE RETURN FOR
MORE CONVECTION TONIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW JUST OFF THE CALIFORNIA COAST...RIDGING OVER THE
WESTERN THIRD OF THE U.S. INTO BRITISH COLUMBIA...AND TROUGHING OVER
CENTRAL CANADA INTO THE NORTHERN PLAINS/UPPER MIDWEST. A COUPLE OF
SHORTWAVES TRAVERSING THROUGH THIS TROUGH IN SOUTH DAKOTA AND MN...
COMBINED WITH A SURFACE TO 850MB COLD FRONT THAT STRETCHED FROM
DULUTH TO SIOUX CITY IA...HAVE AIDED IN MAINTAINING A BAND OF
SHOWERS AND THUNDERSTORMS. THIS BAND EXTENDS FROM WEST CENTRAL IA
THROUGH THE FORECAST AREA. MUCH OF THE ACTIVITY HAS BEEN ELEVATED IN
NATURE DUE TO CAPPING PRESENT OF BL PARCELS. PLENTY OF INSTABILITY
FOR THE CONVECTION WITH CAPE VALUES LIFTED FROM 1 KM BETWEEN 1000-
2000 J/KG. IN THE WAKE OF THE CONVECTION...THERE HAS BEEN A NARROW
AREA OF LOW STRATUS DEVELOPING...BEFORE CLOUDS CLEAR OUT OVER
CENTRAL MN. AIRMASS BEHIND THE COLD FRONT WAS NOT MUCH COLDER THAN
AHEAD...WITH 925MB TEMPS HOVERING BETWEEN 20-24C. HOWEVER...
PRECIPITABLE WATER DROPS SIGNIFICANTLY FROM 1.5-1.75 INCHES TO 1-
1.25 INCHES. UPSTREAM A MORE SIGNIFICANT COLD FRONT EXISTS OVER
NORTHERN NORTH DAKOTA AND NORTHWEST MN WHERE 925MB TEMPS DROP TO 12-
14C.
THE COLLECTION OF SHORTWAVES ACROSS SOUTH DAKOTA AND MN ARE PROGGED
TO CROSS THE FORECAST AREA THIS MORNING...PUSHING THE SURFACE-850MB
COLD FRONT THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z. ANTICIPATING
MUCH OF THE CURRENT CONVECTION AHEAD OF THESE FEATURES TO MARCH
SOUTHEASTWARD OUT OF THE FORECAST AREA BY 13Z PER HIGH RESOLUTION
MODEL CONSENSUS. STILL CARRIED SOME LOW PRECIPITATION CHANCES OVER
THE SOUTHEAST HALF IN THE WAKE OF THE CURRENT ACTIVITY IN THE EVENT
ADDITIONAL SHOWERS/STORMS FORM AS THE SHORTWAVES MOVE IN.
OTHERWISE...SUBSIDENCE AND DRYING OF PRECIPITABLE WATER SHOULD ALLOW
SKIES TO CLEAR AFTER A BRIEF PERIOD OF MORNING STRATUS. THE SUNSHINE
COMBINED WITH 925MB TEMPS OF 18-20C FOR MUCH OF TODAY SHOULD ALLOW
FOR HIGHS TO TOP OUT IN THE 70S IN MOST LOCATIONS...WITH SOME LOW
80S IN VALLEYS.
SHORTLY AFTER 00Z THIS EVENING...ANOTHER LINE OF SHOWERS AND
EMBEDDED THUNDERSTORMS LOOKS LIKELY TO MOVE ACROSS THE REGION...
ESPECIALLY ALONG AND NORTH OF I-90. THIS LINE OF CONVECTION WILL BE
FORCED BY A POTENT SHORTWAVE OVER CENTRAL ALBERTA DROPPING THROUGH
THE UPPER MIDWEST TROUGHING. THE SHORTWAVE SHOULD ALSO HAVE A NARROW
CORRIDOR OF MOISTURE TO WORK WITH AS PRECIPITABLE WATER JUMPS UP TO
1-1.3 INCHES. INSTABILITY WISE...ITS FAIRLY MEAGER WITH VALUES OF
100-500 J/KG...MOSTLY IN THE EVENING DUE TO LOSS OF DAYTIME HEATING
COOLING THE BOUNDARY LAYER. ANTICIPATING MORE THUNDERSTORM ACTIVITY
SHOULD OCCUR TODAY UPSTREAM OVER NORTH DAKOTA INTO CENTRAL MN WHERE
THE JUXTAPOSITION OF HIGHER DIURNALLY BASED INSTABILITY INTERSECTS
THE SHORTWAVE. SHEAR PROFILES WOULD CERTAINLY SUPPORT BOTH A
DAMAGING WIND AND LARGE HAIL THREAT WITH CONVECTION...HOWEVER...THE
MEAGER INSTABILITY BY THE TIME THE CONVECTION MOVES INTO THE
FORECAST AREA SHOULD HELP MITIGATE SEVERE POTENTIAL. MAY STILL SEE
SOME STRONGER WIND GUSTS...THOUGH. HAVE RAISED PRECIPITATION CHANCES
UP FOR THE EVENING HOURS GIVEN VERY GOOD MODEL CONSENSUS FOR THIS
CONVECTION. KEPT SOME PRECIPITATION CHANCES GOING OVERNIGHT TOO
ALONG AND NORTH OF I-94 WHERE A FRONTOGENESIS BAND LOOKS TO SETUP ON
THE NORTH SIDE OF THE SHORTWAVE. LOOK FOR COOLER TEMPERATURES
TONIGHT AS COLDER AIR RUSHES IN BEHIND THE LINE OF CONVECTION. IN
FACT...925MB TEMPS COOL AS MUCH AS 10C ON A BRISK 30-40 KT 925MB
NORTHWEST WIND.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM CDT SAT SEP 20 2014
MAIN CONCERNS ARE ON PRECIPITATION POTENTIAL FOR SUNDAY...FOLLOWED
BY TEMPERATURES AND VALLEY FOG POTENTIAL SUNDAY NIGHT AND BEYOND.
ANOTHER POTENT SHORTWAVE LOOKS TO FOLLOW QUICKLY ON THE HEELS OF THE
ONE MOVING THROUGH THE FORECAST AREA TONIGHT. THIS SHORTWAVE...
CURRENTLY IN NORTHERN SASKATCHEWAN...IS PROGGED TO DROP SOUTH
THROUGH THE FORECAST AREA SUNDAY MORNING. THIS SHORTWAVE WILL HELP
TO PULL THE FRONTOGENESIS BAND AND ASSOCIATED SURFACE COLD FRONT
SOUTHWARD THROUGH THE FORECAST AREA DURING THE MORNING HOURS.
APPEARS THE BULK OF THE RAIN/SHOWER ACTIVITY WITH THE BAND WILL BE
CONFINED TO WISCONSIN...BUT SOME MAY EVEN CREEP ACROSS THE MS RIVER
AS SUGGESTED BY THE 20.00Z ECMWF/CANADIAN. HAVE RAISED PRECIPITATION
CHANCES UPWARDS AND FURTHER INCREASES MAY BE NECESSARY. OVERALL
AMOUNTS LOOK TO BE FAIRLY LIGHT...THOUGH. THIS FRONTAL BOUNDARY
DROPPING SOUTH...925MB TEMPS ONLY TOPPING OUT FROM 10-12C AT 00Z
MONDAY...A BREEZY NORTH WIND AND A DECENT AMOUNT OF SUN NOT
OCCURRING UNTIL LATE IN THE DAY WILL YIELD MUCH COOLER CONDITIONS
COMPARED TO TODAY.
MODELS REMAIN IN GOOD AGREEMENT IN BUILDING HIGH PRESSURE INTO THE
FORECAST AREA FOR SUNDAY NIGHT THROUGH TUESDAY. THIS IS IN RESPONSE
TO THE UPPER RIDGE OVER THE WESTERN THIRD OF THE U.S. MARCHING EAST
INTO MN AND IA BY 12Z TUE. THE MAIN CENTER OF THE HIGH LOOKS TO
TRACK JUST SOUTH OF THE AREA...BUT THE GRADIENT RELAXES ENOUGH TO
ALLOW FOR DECOUPLING BOTH NIGHTS. SOME CLOUDS COULD DRIFT ACROSS
BOTH NIGHTS...BUT IT APPEARS ENOUGH PERIOD OF CLEAR SKIES SHOULD
EXIST FOR VALLEY FOG TO FORM...ESPECIALLY IN THE TRIBUTARIES. SUNDAY
NIGHT WILL BE THE COOLER OF THE TWO NIGHTS DUE TO AIRMASS
MODIFICATION TAKING PLACE ON MONDAY. THE TYPICAL COLD SPOTS IN
CENTRAL WI COULD DIP INTO THE MID/UPPER 30S SUNDAY NIGHT. 925MB
TEMPS OF 12-14C ON MONDAY WITH MORE SUN WILL ALLOW HIGHS TO TOP OUT
IN THE 60S TO LOW 70S...WARMEST IN VALLEYS. THESE 925MB TEMPS CLIMB
ANOTHER 1-2C ON TUESDAY...RESULTING IN A SIMILAR BUMP UP IN HIGHS.
IN GENERAL THE WEATHER REMAINS FAIRLY QUIET FROM TUESDAY NIGHT RIGHT
INTO NEXT WEEKEND...THANKS TO SIGNIFICANT UPPER RIDGING BUILDING UP
OVER THE EASTERN TWO THIRDS OF THE U.S.. IN FACT...MOST LONG RANGE
GUIDANCE IS SUGGESTING A 590 DAM 500MB HIGH TO FORM OVER MICHIGAN BY
00Z SATURDAY...WHICH WOULD BE ABOUT 2 STANDARD DEVIATIONS ABOVE
NORMAL. THIS IS ALL A RESULT OF A VERY DEEP TROUGH DEVELOPING ALONG
THE WEST COAST OF THE U.S....SOMETHING THAT HASNT BEEN SEEN FOR
QUITE SOME TIME. THE ONLY REAL ISSUE TO WORRY ABOUT IS THE CURRENT
UPPER LOW OFF THE CALIFORNIA COAST...WHICH MODELS TRY TO BRING
THROUGH THE FORECAST AREA IN A WEAKENING STATE CENTERED AROUND
WEDNESDAY. HAVE MAINTAINED SOME LOW PRECIPITATION CHANCES ASSOCIATED
WITH THIS FEATURE. DESPITE THE RISING 500MB HEIGHTS...IT TAKES
AWHILE FOR A SIMILAR RESPONSE TO 850MB TEMPS...PARTIALLY DUE TO THAT
UPPER LOW LIFTING THROUGH. THUS...TEMPERATURES HOLD NEAR SEASONABLE
NORMALS UNTIL THE END OF THE WEEK. FRIDAY...SATURDAY AND SUNDAY ALL
LOOK ABOVE NORMAL WITH HIGHS POSSIBLY APPROACHING 80.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1134 PM CDT FRI SEP 19 2014
ACTIVITY HAS UPSCALED ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA SIMILAR TO WHAT THE MESO SCALE MODELS WERE SHOWING. AS
THE CURRENT ACTIVITY CONTINUES TO MOVE EAST...EXPECT THAT KRST
SHOULD BE IMPACTED BY SOME STORMS THROUGH ABOUT 07Z OR SO AND KLSE
THROUGH ABOUT 09Z WITH PRIMARILY MVFR CONDITIONS EXPECTED. SOME
UNCERTAINTY WHETHER ANY SHOWERS WILL LINGER/DEVELOP BEHIND THE
LINE OF STORMS. THE 20.02Z HRRR AND PREVIOUS RUNS HAVE BEEN
SHOWING GROWTH UP INTO WESTERN AND CENTRAL WISCONSIN WITH SOME
SHOWERS IMPACTING KLSE WHILE THE 20.00Z CR-NESTNAM KEEPS
EVERYTHING TO THE SOUTH. GIVEN THAT THE CURRENT ACTIVITY IS
FARTHER NORTH THAN THE CR-NESTNAM CURRENTLY INDICATES WILL HAVE
SOME LINGERING SHOWERS SIMILAR TO THE HRRR. VFR CONDITIONS SHOULD
THEN PREVAIL THROUGH SATURDAY BEHIND THE COLD FRONT WITH NORTHWEST
WINDS AND ENOUGH MIXING TO PRODUCE SOME GUSTS AT KRST. THE NEXT
SHORT WAVE TROUGH WILL RAPIDLY APPROACH FROM THE NORTHWEST
SATURDAY EVENING WITH MODERATE PV ADVECTION IN THE 500-300 MB
LAYER. THIS IS EXPECTED TO PRODUCE SOME SHOWERS AND HAVE INCLUDED
A VCSH FOR THE LAST HALF OF SATURDAY EVENING FOR BOTH SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1134 PM CDT FRI SEP 19 2014
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 222 PM CDT FRI SEP 19 2014
CONCERN FOCUSED ON CONVECTION/SEVERE POTENTIAL TONIGHT.
WATER VAPOR/RAP 500MB ANALYSIS SHOWING A FAIRLY VIGOROUS MID-LEVEL
TROUGH MOVING EAST ACROSS THE DAKOTAS. AT THE SURFACE...LOW PRESSURE
WAS LOCATED OVER SOUTHERN MANITOBA CANADA WITH A TRAILING TROUGH
THROUGH THE EASTERN DAKOTAS INTO CENTRAL NEB. RADAR MOSAIC SHOWING
SCATTERED SHOWERS/ISOLATED THUNDER ACROSS PORTIONS OF ND INTO
NORTHERN MN IN RESPONSE TO CORRIDOR OF 850MB MOISTURE TRANSPORT/310K
ISENTROPIC LIFT AHEAD OF THE APPROACHING TROUGH. OTHERWISE...BREEZY
SOUTH WINDS IN PLACE ACROSS THE FORECAST AREA THIS AFTERNOON WITH
MOSTLY SUNNY SKIES. TEMPERATURES WERE IN THE UPPER 60S TO THE MIDDLE
70S.
FOR TONIGHT...LOOK FOR THAT MID-LEVEL/SURFACE TROUGH TO ROTATE
SOUTHEAST ACROSS THE AREA TONIGHT. MODELS OFFERING UP VARIOUS
SOLUTIONS ON CONVECTIVE SCHEMES BASED ON FAIRLY STRONG CAP IN PLACE.
THINKING WITH INCREASING 850MB MOISTURE TRANSPORT/EVENTUAL
STEEPENING OF MID-LEVEL LAPSE RATES AND LIFT WITH THE TROUGH
PASSAGE...THIS WILL BE ENOUGH FORCING TO SEE AT LEAST A SCATTERED
BAND OF THUNDERSTORMS. THINKING THIS CONVECTION WILL INITIALLY START
OUT ELEVATED IN NATURE ABOVE THE CAP...BUT THEN CAP WEAKENS LATE
THIS EVENING INTO THE OVERNIGHT HOURS ALLOWING FOR AN UPTICK IN
THUNDERSTORM COVERAGE. STILL THINKING THERE IS A MARGINAL SEVERE
THREAT. MODEL CONSENSUS SHOWING 0-3KM MUCAPE VALUES OF 1000-200J/KG
ALONG WITH EFFECTIVE BULK SHEAR AROUND 30KT. THIS COULD PRODUCE A
FEW VIGOROUS/ROTATING UPDRAFTS CAPABLE OF LARGER HAIL PRODUCTION
AND DAMAGING WIND POTENTIAL.
LINGERING SHOWERS/THUNDERSTORMS WILL BE POSSIBLE ACROSS SOUTHERN WI
INTO NORTHEAST IA ON SATURDAY AS THE TROUGH CONTINUES TO ROTATE
SOUTHEAST OUT OF THE AREA. FOR LATER SATURDAY AFTERNOON INTO
SATURDAY EVENING...MODELS SHOWING A FAIRLY COMPACT/VIGOROUS PV-
ANOMALY ROTATING SOUTHEAST OUT OF THE NORTHERN PLAINS IN OUR AREA.
THE BULK OF THE FORCING WITH THIS FEATURE SEEMS TO BE FOCUSED ALONG
AND NORTHEAST OF I-94. AS SUCH...WENT WITH THE LIKELIHOOD OF
SHOWERS/ISOLATED THUNDER NORTHEAST OF I-94 AND TAPERED TO LOWER-END
CHANCES ACROSS NORTHEAST IA/FAR SOUTHWEST WI. WITH THE WARMER START
TO SATURDAY...LOOK FOR HIGHS TO PERK UP INTO THE 70S TO A FEW LOWER
80S ALONG AND SOUTH OF I-90. LOOK FOR THE SHOWERS AND ISOLATED
STORMS TO TAPER OFF/MOVE EAST OF THE AREA BY MIDNIGHT SATURDAY
NIGHT WITH OVERNIGHT LOWS DIPPING INTO THE 50S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 222 PM CDT FRI SEP 19 2014
COOLER CYCLONIC FLOW ALOFT ON SUNDAY WILL PRODUCE COOLER
TEMPERATURES IN THE 60S ALONG WITH BREEZY NORTHWEST WINDS. ALSO
LOOKS LIKE THERE WILL ALSO BE ENOUGH INSTABILITY NORTHEAST OF I-94
TO PRODUCE A FEW SHOWERS.
HIGH PRESSURE BUILDS OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION
SUNDAY NIGHT. CLEAR SKIES AND LIGHT/CALM WINDS WILL SET UP IDEAL
RADIATIONAL COOLING FOR AREAS OF FOG...ESPECIALLY FAVORED RIVER
VALLEY LOCATIONS AND THE SANDY/BOG COUNTRY OF CENTRAL WI. PLAN ON
LOWS IN THE LOWER 40S OVER CENTRAL WI...AND IN THE MIDDLE/UPPER 40S
ELSEWHERE ACROSS THE FORECAST AREA.
AFTER A COOL/POTENTIALLY FOGGY START...HIGH PRESSURE LOOKS TO
PROVIDE A DRY/QUIET/MOSTLY SUNNY MONDAY WITH HIGHS MIDDLE 60S TO
NEAR 70.
FOR TUESDAY THROUGH FRIDAY...A RIDGE OF HIGH PRESSURE TRIES TO
ESTABLISH ITSELF OVER THE CENTRAL CONUS. HOWEVER...MODELS SHOWING A
TROUGH EJECTING OUT OF THE INTERMOUNTAIN WEST INTO THE UPPER
MISSISSIPPI RIVER VALLEY BY WEDNESDAY INTO THURSDAY. BELIEVE THIS
MAY BE A BIT OVER DONE...BUT WILL GO WITH MODEL CONSENSUS AT THIS
POINT AND INCLUDE SMALL-END SHOWER/THUNDER CHANCES IN THE TUESDAY
NIGHT THROUGH THURSDAY PERIOD. AS THE TROUGH MOVES OFF TO THE
EAST...THE RIDGE RE-ESTABLISHES ITSELF ON FRIDAY FOR DRIER/WARMER
CONDITIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1134 PM CDT FRI SEP 19 2014
ACTIVITY HAS UPSCALED ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA SIMILAR TO WHAT THE MESO SCALE MODELS WERE SHOWING. AS
THE CURRENT ACTIVITY CONTINUES TO MOVE EAST...EXPECT THAT KRST
SHOULD BE IMPACTED BY SOME STORMS THROUGH ABOUT 07Z OR SO AND KLSE
THROUGH ABOUT 09Z WITH PRIMARILY MVFR CONDITIONS EXPECTED. SOME
UNCERTAINTY WHETHER ANY SHOWERS WILL LINGER/DEVELOP BEHIND THE
LINE OF STORMS. THE 20.02Z HRRR AND PREVIOUS RUNS HAVE BEEN
SHOWING GROWTH UP INTO WESTERN AND CENTRAL WISCONSIN WITH SOME
SHOWERS IMPACTING KLSE WHILE THE 20.00Z CR-NESTNAM KEEPS
EVERYTHING TO THE SOUTH. GIVEN THAT THE CURRENT ACTIVITY IS
FARTHER NORTH THAN THE CR-NESTNAM CURRENTLY INDICATES WILL HAVE
SOME LINGERING SHOWERS SIMILAR TO THE HRRR. VFR CONDITIONS SHOULD
THEN PREVAIL THROUGH SATURDAY BEHIND THE COLD FRONT WITH NORTHWEST
WINDS AND ENOUGH MIXING TO PRODUCE SOME GUSTS AT KRST. THE NEXT
SHORT WAVE TROUGH WILL RAPIDLY APPROACH FROM THE NORTHWEST
SATURDAY EVENING WITH MODERATE PV ADVECTION IN THE 500-300 MB
LAYER. THIS IS EXPECTED TO PRODUCE SOME SHOWERS AND HAVE INCLUDED
A VCSH FOR THE LAST HALF OF SATURDAY EVENING FOR BOTH SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1109 PM CDT FRI SEP 19 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 854 PM CDT FRI SEP 19 2014
FORECAST FROM THE DAY SHIFT APPEARS TO BE ON TRACK. TSTMS HAVE
INCREASED OVER THE PAST HOUR IN WEST CENTRAL WI...WHERE STRONG
0-1 KM MOISTURE CONVERGENCE...THE RRQ OF A 90 KT JET STREAK AND
AN INSTABILITY AXIS (MUCAPE 1000-1500 J/KG) ARE ALIGNED. EXPECT
PCPN TO GRADUALLY SHIFT E/SE ACROSS THE FORECAST OVERNIGHT...
AS THE LLJ VEERS WEST AND THE RRQ OF THE UPPER JET PULLS THROUGH.
NOT SURE ABOUT THE COVERAGE OF THE SHRA/TSRA ACTIVITY YET...SO
WILL STICK WITH HIGH CHC POPS FOR NOW. WILL MONITOR OVER THE NEXT
HOUR AND SEE IF POPS NEED TO BE INCREASED.
STILL ANTICIPATE THE POSSIBILITY OF A FEW STRONG STORMS...AS
DEEP LAYER SHEAR IS 40-50+ KTS AND MID-LEVEL LAPSE RATES ARE
STEEP (7-8 C/KM). THE PRESENCE OF A 40-50 KT LLJ WILL ALSO
ENHANCE THE THREAT OF STRONG TSTM WINDS...ALTHOUGH MOST OF
THE INSTABILITY WILL BE ELEVATED.
&&
.SYNOPSIS...
ISSUED AT 243 PM CDT FRI SEP 19 2014
WARM AND A BIT MORE HUMID EARLY IN THE WEEKEND...THEN BRIEFLY
COOLER BEFORE TURNING MILD AND MAINLY DRY NEXT WEEK.
INITIALLY LOW- AMPLITUDE BAND OF WESTERLIES ACRS SRN CANADA AND
THE NRN CONUS WL UNDERGO AMPLIFICATION DURING THE WEEKEND...WITH
UPR RIDGE BUILDING OVER THE INTERMOUNTAIN WEST AND A TROF
DEEPENING THROUGH THE GREAT LAKES RGN. A SLOW PROGRESSION OF THE
LARGE SCALE FEATURES IS EXPECTED...WITH THE POSITIVE ANOMALY ASSOC
WITH THE WRN RIDGE SHIFTG TO THE JAMES BAY REGION BY THE MIDDLE OF
NEXT WEEK...BEFORE THE PROGRESSION SLOWS. THAT WL LEAVE HIGH UPR
HEIGHTS ACRS THE ERN CONUS LATE NEXT WEEK THROUGH THE FOLLOWING
WEEKEND...WITH THE MAIN WESTERLIES WELL TO THE N ACRS CANADA.
TEMPS WL START OUT ABV NORMAL...BRIEFLY DROP TO BLO NORMAL LEVELS
LATE IN THE WEEKEND...THEN WARM BACK TO ABV NORMAL FOR MOST OF
NEXT WEEK. THE MAIN OPPORTUNITY FOR PCPN WL OCCUR EARLY IN THE
FCST PERIOD. UPR RIDGING DOMINATING THE AREA THEREAFTER WL ALLOW
FOR ONLY SCT LGT SHOWERS AT MOST...AND QUITE POSSIBLY TOTALLY DRY
WEATHER FOR THE MIDDLE TO LATTER PART OF THE PERIOD.
&&
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW FLATTENED
MID-LEVEL TROUGHING ACROSS THE NORTHERN PART OF THE COUNTRY FROM
MONTANA TO LAKE SUPERIOR. WITHIN THIS TROUGHING...SEVERAL
SHORTWAVES ARE MOVING TO THE EAST AND ARE CREATING AREAS OF SHOWERS
AND STORMS. ONE AREA IS LOCATED OVER NORTHERN MINNESOTA WHILE
ANOTHER CLUSTER IS OVER FAR NORTHERN LAKE SUPERIOR. A FEW SHOWERS
EXTENDING SOUTHWARD FROM THE LATTER CLUSTER ARE PASSING OVER N-C
WISCONSIN EARLY THIS AFTERNOON. FOR THE REST OF THE AFTERNOON...THE
AREA TO FOCUS ON IS OVER MINNESOTA WHERE PWATS ARE GREATER THAN 1.50
INCHES BUT STILL WAITING FOR INSTABILITY TO ARRIVE. IF THIS AREA
CAN DESTABILIZE LATER THIS AFTERNOON...COULD SEE SOME STRONG STORMS
DEVELOP. THE SURFACE COLD FRONT TRAILS THIS AREA AND REMAINS OVER
THE EASTERN DAKOTAS. AS THE UPSTREAM SHORTWAVES AND COLD FRONT MOVE
THROUGH THE REGION OVER THE NEXT 24 HOURS...PRECIP TIMING AND
THUNDERSTORM POTENTIAL ARE THE MAIN FORECAST CONCERNS.
TONIGHT...PIECES OF SHORTWAVE ENERGY OVER NORTHERN PLAINS WILL MOVE
INTO THE WESTERN GREAT LAKES REGION THIS EVENING. ALONG THE LEADING
EDGE OF THIS ENERGY...MODELS SHOW A RIBBON OF DEEP MOISTURE WITH
PWATS APPROACHING 1.75 INCHES ALONG WITH INCREASING FORCING IN THE
FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL SAG SOUTHEAST
ACROSS THE NORTHWEST HALF OF WISCONSIN THIS EVENING AND NORTHEAST
WISCONSIN OVERNIGHT. VARIOUS MODELS INCLUDING THE RUC/SREF/NAM ALL
DEVELOP MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS LATE THIS
AFTERNOON OR EARLY THIS EVENING OVER WESTERN WISCONSIN COINCIDENT
WITH A RIBBON OF ELEVATED CAPES UPWARDS OF 1000 J/KG. SPC
HIGHLIGHTS THIS AREA FOR A THREAT OF STRONG TO NEAR SEVERE STORMS.
THE FORCING AND RIBBON OF DEEP MOISTURE LOOK TO OUTRUN THIS
INSTABILITY AXIS BY LATE IN THE EVENING AND OVERNIGHT...BUT NOT OUT
OF THE QUESTION THAT A FEW STRONG STORMS (IF THEY DEVELOP) COULD
MAKE IT INTO CENTRAL WISCONSIN BY MID TO LATE EVENING BEFORE
WEAKENING THEREAFTER. WITH THE JET OVERHEAD...STRONG GUSTY WINDS
WOULD BE THE MAIN THREAT FOLLOWED BY SMALL HAIL. COVERAGE OF
SHOWERS AND STORMS SHOULD DIMINISH TO SCATTERED BY THE TIME THEY
REACH NE WISCONSIN OVERNIGHT. BEHIND THE STORMS...A LOW STRATUS
DECK SHOULD SPREAD ACROSS THE AREA...WHICH COULD ALSO CREATE PATCHY
FOG IN SPOTS. A WARM NIGHT WITH LOWS IN THE UPPER 50S TO LOWER 60S.
SATURDAY...A FEW SHOWERS AND ISOLATED STORMS WILL BE EXITING
EAST-CENTRAL WISCONSIN EARLY IN THE MORNING AND MAY ALSO HAVE A FEW
SHOWERS OVER N-C WISCONSIN AS WELL. BUT OTHERWISE...THE DAY SHOULD
START OUT RATHER CLOUDY WITH A LOW OVERCAST DECK IN PLACE. THE LOW
STRATUS WILL LIKELY SLOW THE HEATING CURVE FOR A FEW HOURS IN THE
MORNING...BUT SHOULD LIFT WITH MIXING BY MID TO LATE MORNING. THE
TRAILING SURFACE FRONT WILL BE MOVING ACROSS CENTRAL AND
NORTH-CENTRAL WISCONSIN DURING THIS TIME BUT THE CLOUD COVER SHOULD
KEEP THE FRONT RELATIVELY INACTIVE. AS IT REACHES NORTHEAST AND
EAST-CENTRAL WISCONSIN BY MIDDAY TO EARLY AFTERNOON...POTENTIAL WILL
BE THERE FOR DAYTIME HEATING TO CREATE SURFACE BASED INSTABILITY
OVER THAT PART OF THE STATE. THE NAM GENERATES CLOSE TO 1500 J/KG
OF ML CAPE OVER EAST-CENTRAL WISCONSIN ASSUMING TEMPERATURES CAN
REACH INTO THE MIDDLE 70S. BUT CONVERGENCE ALONG THE FRONT IS
RELATIVELY WEAK AND THERE WILL LIKELY BE A CAP TO OVERCOME. SO
THINK THE POTENTIAL FOR REDEVELOPMENT OF THUNDERSTORMS IS PRETTY LOW
BECAUSE OF THESE FACTORS. HIGHS IN THE UPPER 60S NORTH TO MIDDLE OR
UPPER 70S SOUTH.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 243 PM CDT FRI SEP 19 2014
UPR SPEED MAX AND SHARPENING SHRTWV WL DIG SE ACRS THE FCST AREA
SAT NGT AS LARGE SCALE AMPLIFICATION OCCURS. THE STG DYNAMICS WL
BE FAVORABLE FOR PCPN...ESP ACRS THE N. RAISED POPS TO
CATEGORICAL THERE...TAPERING TO A HIGH-END CHC ACRS THE S.
INSTABILITY WON/T BE GREAT...BUT WL PROBABLY BE SUFFICIENT FOR
THUNDER GIVEN THE DYANMICS. TRENDED TOWARD THE HIGH QPFS OF THE
MODELS WITH THE BETTER DEFINED SFC REFLECTION.
BLUSTERY...CLDY...AND MUCH COOLER CONDITIONS ARE LIKELY SUN...
WITH LINGERING SHRA OVER MAINLY THE N/NE/E. TRIMMED MAX
TEMPS...BUT WOULD NOT BE SURPRISED IF THEY END UP EVENTUALLY
NEEDING A BIT MORE PRUNING.
TEMPS SUN NGT TRICKY BECAUSE THEY/LL DEPEND ON CLDS. THINK THERE
WL STILL BE ENOUGH OF A NW FLOW DOWN ACRS LAKE SUPERIOR TO KEEP
THINGS A LITTLE CLOUDIER THAN MUCH OF THE GUIDANCE IS
INDICATING...SO DID NOT TAKE LOWS DOWN TOO FAR. A FROST/FREEZE
WOULD CERTAINLY BE POSSIBLE ACRS MUCH OF THE AREA IF WE TOTALLY
CLEAR OUT.
UPR HEIGHTS REBOUND QUICKLY LATER SUN NGT AND MON...SO THE COOLER
WX WL BE SHORT-LIVED. MODELS HINT THAT WK SHRTWVS WORKING ARND
THE WRN FLANK OF THE UPR RIDGE COULD BRUSH THE AREA AT TIMES.
THAT RESULTED IN SOME LOW-CHC POPS IN THE EXTENDED FCST
INITIALIZATION GRIDS. THAT/S CERTAINLY HARD TO RULE OUT SO LET
THOSE RIDE IN THE FCST. BUT OVERALL...FORCING WL BE WEAK AND
MOISTURE LIMITED...SO EXPECTING A MAINLY DRY PERIOD WITH ABV
NORMAL TEMPS.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1103 PM CDT FRI SEP 19 2014
LLWS WILL CONTINUE TONIGHT...BUT SHOULD WEAKEN AT THE WESTERN TAF
SITES BY 09Z-10Z...AND AT THE EASTERN TAF SITES BY 12Z-14Z/SAT.
SCT SHOWERS AND TSTMS ARE EXPECTED TO MOVE THROUGH THE FORECAST
AREA OVERNIGHT. DID ADD A TEMPO GROUP FOR TSTMS AT CWA/AUW EARLY
THIS MORNING (LOW-LEVEL JET AND UPPER JET STREAK)...AND A PROB30
GROUP FOR TSTMS AT GRB/ATW/MTW IN THE EARLY AFTERNOON (COLD
FRONTAL PASSAGE). MVFR CONDITIONS MAY ACCOMPANY THE SHOWERS AND
STORMS. STRATUS IS EXPECTED TO SPREAD ACROSS THE FORECAST AREA
OVERNIGHT INTO EARLY SATURDAY. IFR CONDITIONS ARE POSSIBLE...
ESPECIALLY OVER NC/C WI. EXPECT LOW CIGS TO GRADUALLY IMPROVE AS
THE COLD FRONT MOVES THROUGH THE REGION ON SATURDAY.
A STRONG UPPER LEVEL DISTURBANCE WILL SPREAD SHOWERS AND ISOLD
THUNDERSTORMS OVER THE REGION SATURDAY EVENING. MVFR/IFR
CONDITIONS ARE POSSIBLE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1204 AM MDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 913 PM MDT FRI SEP 19 2014
A NUMBER OF OUTFLOW BOUNDARIES HAVE BEEN SITUATED ACROSS EASTERN
LARAMIE COUNTY THIS EVENING...AND INTERACTED WITH WHAT APPEARS
TO BE A PREFRONTAL TROUGH MOVING EAST ACROSS THE CWA TO MAINTAIN
DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE
I-80 CORRIDOR. A FEW SHOWERS CONTINUE TO POP UP AT THIS HOUR FROM
EASTERN LARAMIE COUNTY AND POINTS TO THE EAST...BUT THINK THE
MAIN SFC AND MID LEVEL FORCING HAS PUSHED SOUTH AND EAST OF THE
CWA BASED ON SATELLITE IMAGERY. WILL KEEP WIDELY SCATTERED
COVERAGE FOR SHOWERS WITH MENTION OF ISO-T THROUGH 06Z FOR THIS
AREA...BUT THIS MAY BE OVERLY OPTIMISTIC BASED ON RADAR TRENDS
ALREADY TAKING A DOWNWARD TURN. THE MAIN SFC COLD FRONT LOOKS TO
BE JUST NORTH OF THE CWA AND WILL CONTINUE TO MOVE SOUTH
OVERNIGHT. FOCUSED HIGHEST CLOUD COVER ALONG THE LARAMIE RANGE
THROUGH THE EARLY MORNING HOURS AS MODELS HINT AT A SCT STRATUS
DECK ACCOMPANYING THE FRONT ALONG WITH NORTH-NORTHEAST UPSLOPE
FLOW. OTHERWISE...FORECAST IS IN GOOD SHAPE.
&&
.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 TODAY`S 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 COOL DOWN FROM TODAY`S 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. MID LEVEL 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 MID LEVEL
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 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM MDT SAT SEP 20 2014
WINDS WILL SHIFT TO NORTH AND NORTHEAST WITH THE PASSAGE OF A WEAK
COLD FRONT. UPSLOPE MAY LEAD TO SCATTERED LOW STRATUS ALONG THE
LARAMIE RANGE BY SATURDAY MORNING. OTHERWISE...VFR WILL PREVAIL.
EAST TO NORTHEAST WINDS WILL BE BREEZY AT TIMES FOR THE PLAINS
SATURDAY.
&&
.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.
&&
$$
UPDATE...RJM
SHORT TERM...HAMMER
LONG TERM...FINCH
AVIATION...JAMSKI
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
833 AM PDT Sat Sep 20 2014
.Synopsis...
Lingering Sierra showers/t-storms are possible through the
weekend, otherwise, dry & warmer temperatures into early next
week. Cooler and wetter weather arrives middle of next week into
next weekend.
&&
.Discussion...
Satellite imagery shows a cut off 578dm closed low centered just
west of the Channel Islands near Oxnard. This closed circulation
center is sitting directly under the apex of a ridge covering most
of the western US. Water vapor imagery indicates cloud enhancement
is presently occurring over the Motherlode and west slope of Sierra
Nevada this morning. Due to this and other subtle discrepancies, we
have decided to increase coverage and probability of precipitation
throughout the next 12 hours and sent out an update. Near term
model guidance is fairly consistent in bringing in showers/thunderstorms
above 4000 feet in the Sierra. Unfortunately, the HRRR model,
which has quickly become an office favorite for short term
guidance is currently unavailable. The NAM12 model has been
overforecasting convection over the last week, so we are throwing
out that model as it again appears to be overforecasting
the weekends convection. We will continue to keep a close watch on
the development of any convection in the northeastern sector of the
closed low and send out updates as necessary. DRP
.Previous Discussion...
A closed low is currently straddling the central CA coastline. It
will linger over our region today and gradually move northeastward
by tonight. On Sunday, the low will be centered over Nevada with
the backside of the low still impacting the Sierra. Have kept
mention of showers and thunderstorms over the Sierra this weekend.
The WRF model indicates that there will be more showers on the
western side of the crest Sunday. The rest of our CWA will remain
dry with near to above normal temperatures through Tuesday.
Daytime highs will generally be at their warmest today compared to
the rest of the upcoming 7 days. For the short term forecast, max
temperatures will range mid 80s to upper 90s across the valley.
Smoke from the King Fire will continue to impact the Sierra and
foothills into the adjacent Southern Sacramento valley. Hazy
conditions surrounding the smoky area will extend from the
Central Sacramento valley into the Northern San Joaquin valley. On
Sunday, general wind pattern will transition to a weak onshore
flow which should push smoky/hazy conditions eastward.
Short wave ridging behind the closed upper low moves over NorCal
Sunday into Monday for dry weather. Temperatures trend down slightly
over the weekend but remain near to a little above normal into
Monday. JBB
.Extended Discussion (Wednesday through Saturday)
Models remain in good agreement that a stronger trough will
impact the region from Wednesday into the weekend. On Wednesday,
max temperatures will finally dip below normal. In addition, the
chance for showers will start impacting the NorCal coastline
Wednesday morning. Showers should spread over the Coastal range
and nudge into the Sacramento valley by Wednesday afternoon/evening.
The chance of showers will continue to spread eastward and
southward encompassing the majority of our CWA Thursday and
Friday. Daytime highs will be well below normal Thursday into
Saturday ranging 5 to 15 degrees below average. The one
discrepancy to watch in the models is that the GFS is more
progressive in moving the trough eastward out of our region on
Saturday while the ECMWF model has the trough still lingering.
Have kept mention of showers on Saturday, but started to diminish
them across the valley by Saturday night. JBB
&&
.Aviation...
VFR conditions the next 24 hours all TAF sites. MVFR visibility in
smoke possible in the vicinity of the King Fire. Isolated TS also
possible along the higher Sierra 18z today through 06Z Sunday.
North to east winds to 10 knots this morning transitioning to
southerly this afternoon and tonight.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
1015 AM EDT SAT SEP 20 2014
.UPDATE...
WET CONDITIONS EXPECTED AGAIN TODAY ACROSS SOUTH FLORIDA. LIGHT
SHOWERS WERE MOVING ACROSS THE GULF AND THE LAKE REGION THIS
MORNING. PWATS ON THE 12Z SOUNDING WERE JUST ABOVE 2 INCHES. AN
AREA OF LOW PRESSURE OFF THE EAST COAST OF CENTRAL FLORIDA WILL
DEEPEN AS IT MOVES NORTHEAST TODAY...WITH DEEP TRAILING MOISTURE
REMAINING ACROSS SOUTH FLORIDA. LIFT IS EXPECTED TO INCREASE
ACROSS THE LAKE REGION THROUGH THE DAY AS A SHORTWAVE ROTATES
AROUND THE BASE OF THE UPPER LOW LOCATED ACROSS THE
GEORGIA/FLORIDA BORDER. THE MAJOR LIMITING FACTOR THIS AFTERNOON
WILL BE CLOUD COVER...ESPECIALLY ACROSS THE LAKE REGION.
HOWEVER...WITH THE SYNOPTIC FEATURE ENHANCING LIFT...EXPECT
WIDESPREAD SHOWERS AND A FEW STORMS ACROSS THE NAPLES AREA AND
LAKE REGION. THE FIRST VISIBLE IMAGES THIS MORNING SHOW BREAKS
IN THE CLOUDS ACROSS THE SOUTHERN PORTION OF THE REGION...AND THE
DIFFERENTIAL HEATING MAY ALLOW FOR SHOWER AND STORM DEVELOPMENT
ACROSS THE EAST AND SOUTHEAST COAST IN THE AFTERNOON. THE HRRR AND
LOCAL WRF MODELS ARE HINTING AT THIS POSSIBILITY. SO KEPT THE
LIKELY POPS IN FOR THE REST OF THE REGION AS WELL. TEMPERATURES
WILL BE BELOW NORMAL ACROSS THE REGION DUE TO THE CLOUD COVER AND
RAINFALL.
&&
.PREV DISCUSSION... /ISSUED 855 AM EDT SAT SEP 20 2014/
AVIATION...
DESPITE THE EXTENSIVE MORNING CLOUD COVERAGE...THE LATEST VISIBLE
SATELLITE IMAGERY HAS ALREADY BEGUN TO INDICATE SOME OF THIS
COVERAGE THINNING OR BREAKING UP. IF THIS TREND
CONTINUES...DAYTIME HEATING COMBINED WITH AN UPPER TROUGH AND WEAK
FRONTAL BOUNDARY WILL SUPPORT SHRAS/TSTMS ONCE AGAIN THIS
AFTERNOON...POSSIBLY LATER DUE TO THE CURRENT CLOUD COVERAGE. WITH
THE WSW LOW-LEVEL FLOW IN PLACE...ANY SHRA/TSTM DEVELOP SHOULD
FOCUS TOWARD THE EAST COAST TODAY. 85/
PREV DISCUSSION... /ISSUED 418 AM EDT SAT SEP 20 2014/
DISCUSSION...
A WET PATTERN TO CONTINUE THROUGH THE WEEKEND AND MUCH OF NEXT
WEEK ACROSS SOUTH FLORIDA.
SHOWERS ASSOCIATED WITH A WEAK SURFACE TROUGH CONTINUE TO DIMINISH
WHILE PULLING TO THE NORTHEAST AND AWAY FROM SOUTH FLORIDA THIS
MORNING. HOWEVER...MOSTLY CLOUDY SKIES SHOULD REMAIN ACROSS THE
AREA THROUGH MUCH OF THE DAY AS A RESULT. CUTOFF H5 LOW AND
ASSOCIATED SURFACE LOW PRESSURE ACROSS NORTHERN FLORIDA ARE
EXPECTED TO SLOWLY PUSH TO THE NORTHEAST THROUGH THE DAY.
CONCURRENTLY...DEEP MOISTURE WILL CONTINUE TO SURGE INTO THE AREA
WITH MID LEVEL SOUTHWEST FLOW. THIS WILL PRODUCE PWAT VALUES OF
AROUND 2 INCHES ACROSS THE AREA RESULTING IN ANOTHER DAY OF
SHOWERS AND A FEW THUNDERSTORMS.
THE BEST COVERAGE OF SHOWERS AND STORMS LOOKS TO BE ACROSS THE
LAKE OKEECHOBEE AND PALM BEACH COUNTY AREAS WITH CLOSER PROXIMITY
TO THE H5 SHORTWAVE THUS ENHANCING LIFT. CLOUD COVER THROUGH THE
MORNING SHOULD GREATLY LIMIT STRONG THUNDERSTORM POTENTIAL THROUGH
THE AFTERNOON. VIRTUALLY ALL CONVECTIVE PARAMETERS DECREASE
THROUGH THE DAY AS A RESULT. COVERAGE OF SHOWERS AND STORMS SHOULD
DECREASE AGAIN AFTER DARK WITH LIMITED ACTIVITY LINGERING MAINLY
ACROSS THE AREA WATERS.
DEEP SOUTHWEST FLOW ALOFT SHOULD CONTINUE SUNDAY INTO MONDAY
KEEPING A DEEP MOISTURE AXIS ACROSS CENTRAL AND SOUTHERN FLORIDA.
THIS WILL KEEP A RATHER WET PATTERN THROUGH THE END OF THE WEEKEND
AND INTO THE START OF NEXT WEEK ACROSS THE AREA. A FEW MID LEVEL
IMPULSES SLIGHTLY DETACHED FROM THE PARENT H5 SHORTWAVE WELL TO
THE NORTH ARE EXPECTED TO SLIDE TO THE NORTHEAST ACROSS THE
NORTHERN INTERIOR. THIS SHOULD ENHANCE THUNDERSTORM DEVELOPMENT
SLIGHTLY OVER THE AREA FOR THE BEGINNING OF NEXT WEEK.
A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST
THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES
FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE
DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS
DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE
REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER
ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO
SEVERE THUNDERSTORM POTENTIAL LIMITED.
AVIATION...
A WEAK TROUGH OF LOW PRESSURE OVER FLORIDA WILL DEVELOP INTO A
LOW PRESSURE SYSTEM LATER TODAY. THIS LOW WILL KEEP SHOWERS AND
SOME THUNDERSTORMS OVER SOUTH FLORIDA THROUGH THE DAY. BY THIS
EVENING, THE LOW WILL BE EXITING THE AREA AND TAKE MUCH OF THE
PRECIPITATION ALONG WITH IT. FOR TODAY, EXPECTING MOSTLY RAIN
SHOWERS IN THE MORNING AND INTO THE AFTERNOON. IN THE AFTERNOON,
THE CHANCES OF THUNDERSTORMS WILL INCREASE. HAVE PLACED THE PROB30
GROUPS LATER IN THE DAY TO REFLECT THIS FOR THE EASTERN TAF SITES.
OVERALL, MAINLY VFR/MVFR CONDITIONS ACROSS SOUTH FLORIDA, WITH
BRIEF IFR POSSIBLE UNDER HEAVY SHOWERS AND/OR THUNDERSTORMS.
MARINE...
GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD
PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO
THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP
THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS
ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET
OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 73 87 74 / 80 20 60 20
FORT LAUDERDALE 87 76 88 77 / 70 20 60 20
MIAMI 86 76 88 76 / 60 20 60 20
NAPLES 83 75 85 75 / 80 20 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...84/AK
LONG TERM....84/AK
AREA FORECAST DISCUSSION
NWS JACKSON KY
1019 AM EDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 1019 AM EDT SAT SEP 20 2014
BASED ON THE EXPANSION OF THE MID LEVEL AC HAVE OPTED TO GO AHEAD AND
EXPAND THE ISOLATED SHOWERS TO MOST OF EASTERN KENTUCKY. THE MID
LEVEL AC HAS A FEW VERTICAL TOWERS ALREADY SEEN FROM THE OFFICE. WITH
SOME WEAK INSTABILITY COMBINED WITH THE MID LEVEL INSTABILITY...WE
SHOULD SEE A FEW SHOWERS POP UP THIS AFTERNOON. EVERYTHING SHOULD
REMAIN FAIRLY ISOLATED AND THUNDER DOES NOT LOOK LIKE A THREAT AS
INSTABILITY IS NOT STRONG ENOUGH TO SUPPORT IT. OTHERWISE...NO OTHER
CHANGES PLANNED AT THIS TIME.
UPDATE ISSUED AT 740 AM EDT SAT SEP 20 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND
SATELLITE TRENDS. THIS LED TO SOME MINOR ADJUSTMENTS TO HOURLY
TEMPS AND DEWPOINTS TO START THE PERIOD. ANY LINGERING VALLEY FOG
SHOULD BE LIFTING AND DISSIPATING SHORTLY...IF IT HAS NOT ALREADY
DONE SO. WX GRIDS WERE UPDATED ACCORDINGLY AND AN UPDATED ZFP AND HWO
WILL FOLLOW SHORTLY.
CONFIDENCE IN THE EVOLUTION AND PLACEMENT OF ANY SHOWERS
LATER TODAY REMAINS LOWER THAN AVERAGE. THE NAM HAS BEEN THE MOST
INSISTENT ON ISOLATED SHOWER CHANCES FOR TODAY WHILE THE RECENT HRRR
RUNS POINT TOWARD THE POTENTIAL FOR A STRAY SHOWER JUST ABOUT
ANYWHERE IN THE CWA THIS MORNING INTO THE AFTERNOON...BUT ALSO HAD
ACTIVITY EARLIER IN THE MODEL RUN...BETWEEN 8Z AND PRESENT WHICH DID
NOT MATERIALIZE. THE CURRENT FORECAST HAS THE SLIGHT CHANCES ACROSS
THE WEST OR NORTHWEST IN LINE WITH THE HIGHEST 3Z SREF POPS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 355 AM EDT SAT SEP 20 2014
EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED
OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST
INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US...
A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES
WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID
MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT
LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN
INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE
IS MOVING ACROSS THE CANADIAN PLAINS.
THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK
ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO
FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING
NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US.
DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW
PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND
SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED
SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT
WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE
ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT
SHOULD BE CLOSE TO EXITING INTO VA.
SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED
OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS
LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE
RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER
NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH
SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS
SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD
GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A
COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS
FOG WILL TEND TO DISSIPATE AS WELL.
THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE
AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON.
THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO
DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY
ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE
LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS
BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO
GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH
WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS.
THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE
ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH
BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD
FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH
IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF
CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME.
ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE
CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER
TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS
WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY
WINDS...PENDING THE DEGREE OF INSTABILITY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM EDT SAT SEP 20 2014
A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY.
MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME
OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR
OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST
SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE
PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE
DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS
SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS
ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF
THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER
COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH
CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME
CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE
COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO
THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD
FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE
EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO
INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT
DID NOT MENTION FOG AT THIS TIME.
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 DURING
THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO
THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF
STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL
CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER
OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS
HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND.
MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE
LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT
LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 748 AM EDT SAT SEP 20 2014
ASIDE FROM ANY LINGERING VALLEY FOG LIFTING AND DISSIPATING THROUGH
13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL DURING THE
PERIOD. A COLD FRONT AND APPROACHING UPPER LEVEL SYSTEM WILL BRING
AN INCREASE IN CLOUDS LATER IN THE PERIOD...AND ISOLATED SHOWERS OR
PERHAPS A THUNDERSTORM COULD AFFECT AREAS NORTH OF A SME TO LOZ TO
JKL TO SJS LINE VERY LATE IN THE PERIOD. A FEW VALLEY LOCATIONS MAY
AGAIN EXPERIENCE FOG BETWEEN 3Z AND 12Z WITH VIS RESTRICTIONS DOWN TO
IFR OR MVFR...BUT THIS SHOULD NOT AFFECT 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
753 AM EDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 740 AM EDT SAT SEP 20 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND
SATELLITE TRENDS. THIS LED TO SOME MINOR ADJUSTMENTS TO HOURLY
TEMPS AND DEWPOINTS TO START THE PERIOD. ANY LINGERING VALLEY FOG
SHOULD BE LIFTING AND DISSIPATING SHORTLY...IF IT HAS NOT ALREADY
DONE SO. WX GRIDS WERE UPDATED ACCORDINGLY AND AN UPDATED ZFP AND HWO
WILL FOLLOW SHORTLY.
CONFIDENCE IN THE EVOLUTION AND PLACEMENT OF ANY SHOWERS
LATER TODAY REMAINS LOWER THAN AVERAGE. THE NAM HAS BEEN THE MOST
INSISTENT ON ISOLATED SHOWER CHANCES FOR TODAY WHILE THE RECENT HRRR
RUNS POINT TOWARD THE POTENTIAL FOR A STRAY SHOWER JUST ABOUT
ANYWHERE IN THE CWA THIS MORNING INTO THE AFTERNOON...BUT ALSO HAD
ACTIVITY EARLIER IN THE MODEL RUN...BETWEEN 8Z AND PRESENT WHICH DID
NOT MATERIALIZE. THE CURRENT FORECAST HAS THE SLIGHT CHANCES ACROSS
THE WEST OR NORTHWEST IN LINE WITH THE HIGHEST 3Z SREF POPS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 355 AM EDT SAT SEP 20 2014
EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED
OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST
INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US...
A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES
WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID
MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT
LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN
INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE
IS MOVING ACROSS THE CANADIAN PLAINS.
THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK
ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO
FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING
NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US.
DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW
PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND
SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED
SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT
WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE
ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT
SHOULD BE CLOSE TO EXITING INTO VA.
SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED
OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS
LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE
RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER
NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH
SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS
SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD
GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A
COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS
FOG WILL TEND TO DISSIPATE AS WELL.
THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE
AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON.
THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO
DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY
ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE
LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS
BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO
GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH
WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS.
THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE
ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH
BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD
FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH
IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF
CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME.
ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE
CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER
TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS
WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY
WINDS...PENDING THE DEGREE OF INSTABILITY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM EDT SAT SEP 20 2014
A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY.
MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME
OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR
OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST
SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE
PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE
DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS
SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS
ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF
THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER
COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH
CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME
CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE
COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO
THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD
FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE
EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO
INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT
DID NOT MENTION FOG AT THIS TIME.
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 DURING
THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO
THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF
STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL
CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER
OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS
HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND.
MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE
LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT
LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 748 AM EDT SAT SEP 20 2014
ASIDE FROM ANY LINGERING VALLEY FOG LIFTING AND DISSIPATING THROUGH
13Z TO 14Z...VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL DURING THE
PERIOD. A COLD FRONT AND APPROACHING UPPER LEVEL SYSTEM WILL BRING
AN INCREASE IN CLOUDS LATER IN THE PERIOD...AND ISOLATED SHOWERS OR
PERHAPS A THUNDERSTORM COULD AFFECT AREAS NORTH OF A SME TO LOZ TO
JKL TO SJS LINE VERY LATE IN THE PERIOD. A FEW VALLEY LOCATIONS MAY
AGAIN EXPERIENCE FOG BETWEEN 3Z AND 12Z WITH VIS RESTRICTIONS DOWN TO
IFR OR MVFR...BUT THIS SHOULD NOT AFFECT THE TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...JMW
AVIATION...JP
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
616 AM MDT SAT SEP 20 2014
.AVIATION...
12Z TAF CYCLE
WIDESPREAD IFR AND SPOTTY LIFR CIGS AND VSBY ACROSS GOOD PORTION
OF SE PLAINS WEST AND THEN NORTH ACROSS THE EAST SLOPES OF CENTRAL
MT CHAIN AND IMMEDIATELY ADJACENT HIGHLANDS TO THE EAST TIL AT
LEAST 15Z OR 16Z BEFORE SOME RISE OR BREAKS IN CIGS SETS IN.
EXPECT MT OBSCURATIONS AS WELL. ELSEWHERE IN EAST NM CIGS ARE A
LITTLE LESS WIDESPREAD AND GENERALLY MVFR WITH SOME SPOTTY IFR
MIXED IN. THIS ALSO TO IMPROVE MID TO LATE MORN. MOSTLY VFR
CONDITIONS TO WEST OF CENTRAL MT CHAIN. NEAR SFC WIND FLOW TO
TURN TO MORE OF AN EASTERLY COMPONENT AS THE DAY PROGRESSES TODAY.
BELOW CANYONS AND PASSES OF CENTRAL MT CHAIN E TO SE WIND GUSTS
WILL DEVELOP BETWEEN 21 AND 00Z. MAINLY FROM NEAR 00Z AND ABOUT
09Z OR A BIT LATER WIND GUSTS TO REACH BETWEEN 28 AND 35 KTS BELOW
CANYONS...INCLUDING ABQ AND SAF WITH SUSTAINED SPEEDS BETWEEN 15
AND 26 KT. SOME SPOTTY SHRA/TSRA TO REDEVELOP MAINLY SOUTHERN AND
WESTERN AREAS NEAR AND ESPECIALLY AFTER 20Z...FAVORING HIGHER
TERRAIN AT FIRST...MORE ISOLATED ACTIVITY ACROSS NORTHERN MTS.
SOME ACTIVITY TO CONTINUE OVERNIGHT TONIGHT. ALSO SOME MVFR AND
IFR CIGS AGAIN FAIRLY LIKELY LATER TONIGHT ALONG EAST SLOPES
CENTRAL MT CHAIN AS WELL AS SE AND PERHAPS E CENTRAL PLAINS.
43
&&
.PREV DISCUSSION...348 AM MDT SAT SEP 20 2014...
.SYNOPSIS...
VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO
WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER MOISTURE
WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER AND
THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF THE
EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A DISTURBANCE
ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW MOISTURE
FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD EASTWARD INTO NORTHWEST
NEW MEXICO MONDAY AND MOST AREAS TUESDAY. MEANWHILE... TEMPERATURES
WILL REMAIN GENERALLY ABOVE NORMAL ACROSS THE WEST AND BELOW
NORMAL ACROSS THE EAST. BY THE MIDDLE OF NEXT WEEK...A DRYING
TREND WILL TAKE A STRONGER HOLD ON THE AREA...AND TEMPERATURES
WILL BE NEAR TO SLIGHTLY ABOVE NORMAL EXCEPT FOR THE SOUTHEAST
PLAINS WHERE COOLER THAN AVERAGE TEMPERATURE WILL LIKELY LINGER.
&&
.DISCUSSION...
EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE
CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO
DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST
SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK.
VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS
WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS
EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO
GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS
POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER
WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE
EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS
CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY.
AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX
TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS
ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC
MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED.
OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND
UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING
HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE
NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH
TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY
AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE
INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN
SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY
WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE
ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE
EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN
EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY
SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE-
SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO
THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM
MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY
LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR
WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES.
STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS
DEVELOP SUNDAY PM NW ZONES.
CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH
PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM
NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD
FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT
ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE
DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH
INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY
ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR
REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE
WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL
PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE
POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL
EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ
&&
.FIRE WEATHER...
UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT
DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL
SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE
EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM
TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION
EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING
RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN
ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED
ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC
MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO
MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP
ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL
MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE.
AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS
EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR
NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL
WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION
RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40
CORRIDOR.
MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES
IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL
WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO
CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY
ALONG AND NORTH OF I40.
A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA
STARTING TUE INTO AT LEAST THU...THOUGH 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, THOUGH NOT
DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO
APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL
DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS
DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS
POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF
STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN
CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1009 AM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE COAST OF NEW ENGLAND WILL BRING MILD...DRY
AND GUSTY CONDITIONS TO THE REGION TODAY. AS LOW PRESSURE APPROACHES
FROM THE WEST THERE WILL BE AN INCREASING CHANCE OF SHOWERS LATER
TONIGHT...WITH WIDESPREAD SHOWER DEVELOPING ON SUNDAY AS A COLD
FRONT SWEEPS THROUGH THE REGION. THIS FRONT WILL CLEAR THE AREA
DURING MONDAY WITH SOME LINGERING SHOWERS ACROSS THE HIGHER
TERRAIN THROUGH MID-DAY...THEN IT LOOKS AS IF WE WILL BE IN FOR AN
EXTENDED PERIOD OF DRY WEATHER NEXT WEEK AS A LARGE UPPER RIDGE
BUILDS EAST FROM THE MIDWEST.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1008 AM EDT SATURDAY...PRIMARY CHANGES WITH THIS UPDATE WAS
TO OFFER A MORE PESSIMISTIC FORECAST FOR SOUTHERN/EASTERN
VT...WITH UPWARD ADJUSTMENTS TO SKY COVER FOR MUCH OF THE AFTN
HOURS AND ACCORDINGLY LOWERED HIGHS IN THIS GENERAL AREA.
STILL SHAPING UP TO BE A BREEZY SATURDAY WITH STRONG SOUTHERLY
PRESSURE GRADIENT IN PLACE. OVERCAST SKIES THAT ADVECTED
NORTHEASTWARD OVERNIGHT STILL CONTINUES TO PLAGUE MOST OF THE
NORTH COUNTRY THIS MORNING PER VISIBLE IMAGERY. A NARROW AXIS OF
"CLEARING"/PARTLY CLOUDY SKIES EXTENDED ACROSS THE ST. LAWRENCE
VALLEY...FAR NORTHERN CHAMPLAIN VALLEY INTO THE NORTHERN GREENS.
STRONG LOW- LEVEL SOUTH/SOUTHEAST FLOW HELPING TO MAINTAIN LOWER
MOISTURE AND THINK THIS WILL CONTINUE TO BE THE GENERAL IDEA FOR
TODAY. LATEST RAP 0-1KM RH PROGS SUGGEST OVERCAST WILL BE VERY
SLOW TO LIFT ACROSS INTERIOR CENTRAL AND SOUTHERN VT TODAY. HIGHS
MAY STRUGGLE TO REACH THE MID 60S. THAT CONTRASTS WITH EXPECTED
CONDITIONS FOR ST. LAWRENCE AND NORTHERN CHAMPLAIN VALLEYS AS MORE
BREAKS IN CLOUDS WILL ALLOW HIGHS TO RANGE FROM THE UPPER 60S TO
MID 70S.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH MONDAY/...
AS OF 408 AM EDT SATURDAY...DRY CONDITIONS CONTINUE INTO TONIGHT
AS LOW PRESSURE OVER THE GREAT LAKES SHIFTS NORTHEASTWARD INTO
CENTRAL QUEBEC BY 12Z SUNDAY. ATTENDING SURFACE COLD FRONT RUNS
PARALLEL TO THE UPPER FLOW FROM THE SOUTHWEST SO THE ASSOCIATED
PRECIP WILL TAKE AWHILE TO SHIFT EASTWARD INTO THE BTV CWA...LIKELY
REACHING THE ST. LAWRENCE VALLEY RIGHT AROUND DAYBREAK. WITH
INCREASING CLOUDS AND CONTINUED GUSTY WINDS...OVERNIGHT TEMPS WILL
BE RATHER MILD WITH LOWS ONLY IN THE MID 50S TO LOWER 60S...QUITE
A DIFFERENCE FROM FRIDAY MORNING! PRECIP SHIFTS INTO NORTHERN NEW
YORK SUNDAY MORNING BUT NOT INTO THE CHAMPLAIN VALLEY AND EASTERN
VERMONT UNTIL AFTER 18Z. SO FOR SOME...SUNDAY MORNING WILL BE
GENERALLY DRY...MAINLY ACROSS VERMONT...BUT NOT SO MUCH FOR PEOPLE
LIVING IN NORTHERN NEW YORK. HIGH TEMPS ARE A LITTLE TRICKY SUNDAY
AND WILL LARGELY DEPEND ON TIMING OF THE FRONT AND ASSOCIATED
PRECIP AND CLOUDS. HIGHS WILL PUSH A FEW DEGREES WARMER THAN THE
PREVIOUS DAY ACROSS VT IN THE LOW TO MID 70S...WHILE WESTWARD IN
CLOUDS AND PRECIP THEY`LL HOLD IN THE UPPER 60S.
COLD FRONT AND ASSOCIATED PRECIP SHIFT EAST THROUGH THE REGION
SUNDAY NIGHT BUT THE PARENT UPPER LOW LAGS BEHIND...NOT MOVING
THROUGH UNTIL MONDAY AFTERNOON. WITH LINGERING LOW LEVEL MOISTURE
AND LOW/MID LEVEL FLOW TURNING TO THE NORTHWEST FEEL WE`LL SEE
SOME UPSLOPE ENHANCEMENT TO PRECIP ALONG THE SPINE OF THE GREENS
AND NORTHERN DACKS MONDAY...WHILE DOWNSLOPE AREAS WILL LIKELY
REMAIN DRY. BY LATE AFTERNOON AND INTO THE EVENING THOUGH...HIGH
PRESSURE BEGINS TO SHIFT INTO THE GREAT LAKES REGION AND LOW/MID
LEVELS BEGIN TO DRY OUT ACROSS THE BTV CWA SUBSEQUENTLY ENDING
PRECIP. HIGHS MONDAY WILL BE BACK BELOW NORMAL POST FRONTAL
PASSAGE...AND GENERALLY RUN IN THE 50S EXCEPT FOR THE LOWER
CONNECTICUT RIVER VALLEY WHICH WILL BE IN THE LOW TO MID 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 301 AM EDT SATURDAY...A SIGNIFICANT PATTERN CHANGE IS
EXPECTED DURING THE LONG-TERM PERIOD WITH A TREND TOWARD TRANQUIL
WEATHER WITH TEMPERATURES ABOVE SEASONAL AVERAGES. GOOD RUN-TO-RUN
CONSISTENCY CONTINUES TO BE OBSERVED IN THE 00Z OPERATIONAL GFS
AND ECMWF.
A LINGERING MID-LEVEL TROUGH/CYCLONIC FLOW EARLY IN THE PERIOD WILL
BRING PARTLY TO MOSTLY CLOUDY CONDITIONS WITH A SLIGHT CHANCE OF A
RAIN SHOWER MONDAY NIGHT INTO TUESDAY. THE HIGHEST POPS (~25%) ARE
ACROSS THE NORTHERN MOUNTAINS DURING THE DAY TUESDAY...WITH
DEVELOPMENT OF WEAK DAYTIME INSTABILITY. ANY PRECIPITATION WILL BE
LIGHT. THEREAFTER...AN AMPLIFYING DEEP-LAYER RIDGE BUILDS EWD
FROM THE MIDWEST AND GREAT LAKES PROVIDING GENERALLY CLEAR SKIES.
WILL SEE HIGHS IN THE MID 60S WEDNESDAY...AND THEN INTO THE LOW-
MID 70S IN THE VALLEYS ON THURSDAY AND FRIDAY AS AIR MASS
MODERATES. RELATIVELY LIGHT WINDS ARE EXPECTED AS WELL. CLEAR
SKIES/LIGHT WINDS WILL LEAD TO SOME LOCAL NOCTURNAL FOG IN THE
FAVORED RIVER VALLEYS EACH NIGHT FROM TUESDAY NIGHT THROUGH
THURSDAY NIGHT. COLDEST LOW TEMPERATURES WILL BE TUESDAY
NIGHT...GENERALLY IN THE UPPER 30S TO LOWER 40S. THEREAFTER...LOWS
WILL GENERALLY BE IN THE MID-UPPER 40S IN MOST SECTIONS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...AREAS OF MVFR CEILINGS EXPECTED THIS MORNING
AT SLK/RUT/MPV ASSOCIATED WITH STRATUS DECK. THESE CLOUDS WILL
TEND TO LIFT TO VFR BY 15-16Z WITH BETTER LOW-LEVEL MIXING.
WINDS WILL BE INCREASING FROM THE SOUTH TO SOUTHWEST...ESPECIALLY
DURING THE DAYLIGHT HOURS WITH INCREASING PRESSURE GRADIENT. WILL
ALSO BE DEALING WITH LOW-LEVEL WIND SHEAR AT PBG/SLK UNTIL LOW-
LEVELS MIX OUT AFTER 14-15Z THIS MORNING. INCLUDED LLWS IN THE TAFS
AT ABOVE MENTIONED TAF SITES NEXT FEW HRS...WITH STRONGEST SHEAR
BETWEEN 1.5-2 KFT AGL. VFR THIS AFTERNOON. COULD SEE SOME
ADDITIONAL STRATUS/3-5SM BR OVERNIGHT WITH PERIODS OF MVFR
CONDITIONS.
OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...FRONTAL SYSTEM MOVING IN
FROM THE WEST WILL BRING POTENTIAL FOR WIDELY SCATTERED RAIN
SHOWERS DURING THE DAY SUNDAY...WITH PERIODS OF MVFR CEILINGS AND
VSBYS. UPPER TROUGH REMAINS IN PLACE WITH POTENTIAL FOR SCATTERED
SHOWERS SUNDAY NIGHT INTO MONDAY. MAY SEE SOME PERIODS OF
CONTINUING MVFR CEILINGS DURING SUN NIGHT AND MONDAY. GENERALLY
TRENDING VFR MONDAY NIGHT ONWARD WITH DEVELOPING STRONG SURFACE
AND UPPER RIDGE BY MID-WEEK ACROSS THE GREAT LAKES AND NEW
ENGLAND.
&&
.MARINE...
AS OF 408 AM EDT SATURDAY...STRONG SOUTH WINDS WILL CONTINUE
ACROSS LAKE CHAMPLAIN TODAY AND RIGHT INTO SUNDAY MORNING WITH
HIGH PRESSURE TO OUR EAST AND LOW PRESSURE APPROACHING FROM THE WEST.
SPEEDS OF 20 TO 30 KNOTS ARE EXPECTED DURING THIS TIME PERIOD WITH
GUSTS AS HIGH AS 35 KNOTS AT TIMES. WAVES WILL BUILD INTO THE 2 TO
5 FOOT RANGE MAKING FOR ROUGH BOATING CONDITIONS FOR A GOOD PART
OF THE WEEKEND. AS A RESULT...A LAKE WIND ADVISORY REMAINS IN EFFECT
THROUGH AT LEAST SUNDAY MORNING.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...LAHIFF/LOCONTO
SHORT TERM...LAHIFF
LONG TERM...BANACOS
AVIATION...BANACOS
MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
747 AM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE WILL RIDGE INTO THE REGION FROM THE NORTH TODAY. LOW
PRESSURE WILL MOVE NORTHEAST SUNDAY JUST OFF THE COAST. A COLD
FRONT WILL MOVE THROUGH MONDAY. HIGH PRESSURE BEHIND THE FRONT
WILL PASS BY TO THE NORTH TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 730 AM SAT...MINOR UPDATE TO FORECAST TO CAPTURE T/TD AND
PRECIP TRENDS THIS MORNING.
1030 MB HIGH PRES CENTERED OFF THE NEW ENGLAND COAST CONTINUES TO
RIDGE SWWD INTO THE REGION WHILE AN INVERTED TROUGH OVER THE
OFFSHORE WATERS IS ADVANCING TOWARD THE COAST AND A 1012 MB LOW
PRES IS DEVELOPING OFF THE EAST COAST OF FL. MEANWHILE A WEAK
UPPER LOW RESIDES OVER THE SOUTHEAST STATES WITH A NORTHERN STREAM
SHORTWAVE TROUGH MOVING INTO THE GREAT LAKES.
THE UPPER TROUGH WILL CONTINUE TO DIG INTO THE MIDWEST AND GREAT
LAKES THROUGH THE PERIOD AND WILL BEGIN TO ABSORB THE UPPER LOW
OVER THE SOUTHEAST WHICH IN RESPONSE WILL LIFT THE SFC LOW NORTH
JUST OFF THE SOUTHEAST COAST. EXPECT THE COASTAL TROUGH TO MOVE
INTO EASTERN SECTIONS TODAY THEN GRADUALLY DISSIPATE WHILE THE SFC
LOW LIFTS NORTH TO OFF THE SC COAST BY LATE IN THE PERIOD.
A FEW SHOWERS SHOWING UP ON RADAR ACROSS THE COASTAL WATERS ASSOC
WITH THE COASTAL TROUGH AND EXPECT THESE TO CONTINUE TO ADVANCE
TOWARD THE COAST THROUGH THE MORNING. THE BEST CHANCE OF
SHOWERS...AND POSSIBLY AN ISOLATED THUNDERSTORM...WILL OCCUR
ACROSS EASTERN SECTIONS TODAY AS THE SHOWERS WILL TEND TO
DISSIPATE AS THEY MOVE INTO A DRIER AIRMASS RIDGING IN FROM THE
NORTH. IN ADDITION...COULD SEE SOME SHOWERS ASSOC WITH THE LOW TO
THE SOUTH LIFTING TOWARD THE REGION BY LATE AFTERNOON...MAINLY
AFFECTING THE CRYSTAL COAST. MOSTLY CLOUDY SKIES EXPECTED EASTERN
SECTIONS WITH VARIABLY CLOUDY SKIES TO THE WEST. HIGHS TODAY WILL
REACH A COUPLE DEGREES EITHER SIDE OF 80.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 230 AM SAT...THE SFC LOW WILL CONTINUE TO LIFT NORTH ALONG
THE COAST TONIGHT AND MODELS IN FAIRLY CLOSE AGREEMENT WITH THE
LOW POSITIONED SE OF CAPE LOOKOUT BY 12Z SUN. SLIGHTLY IMPROVING
UPPER LEVEL SUPPORT WITH A STRENGTHENING JET STREAK JUST TO THE
NORTH COUPLED WITH LOW LEVEL CONVERGENCE NEAR THE COASTAL TROUGH
AND SFC LOW WILL BRING A DESCENT CHANCE OF SHOWERS ACROSS EASTERN
SECTIONS TONIGHT. THERE WILL LIKELY BE A SHARP GRADIENT OF PCPN
ACROSS THE REGION WITH BEST CHANCES EAST OF HIGHWAY 17 WHERE
FORCING WILL BE MORE FAVORABLE AND MOISTURE WILL BE GREATER.
MODELS NOT IN BEST AGREEMENT WITH PRECIP AMOUNTS BUT COULD SEE AS
MUCH AS 1/2 TO 1" ALONG THE IMMEDIATE COAST FROM AROUND CAPE
LOOKOUT TO OREGON INLET BUT THEN TAPER OFF RATHER QUICKLY WEST OF
A LINE FROM JACKSONVILLE TO NEW BERN TO COLUMBIA. LOWS EXPECTED IN
THE MID 60S WELL INLAND TO LOWER 70S ALONG THE COAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 232 AM SAT...ACTIVE PATTERN THROUGH THE FIRST PART OF THE LONG
TERM PERIOD. MODELS AGREE THAT CUT OFF UPPER LOW OVER THE FL/GA AREA
WILL MOVE UP THE COAST AS IT DEEPENS. ACCOMPANYING SURFACE LOW WILL
SKIRT THE COAST...AND IS EXPECTED TO BE ALONG THE NORTH CAROLINA
COAST SUNDAY MORNING. UPPER LEVEL ENERGY WILL BE CENTERED
OFFSHORE...THIS WILL HELP KEEP HIGH CHANCES OF PRECIPITATION
CONFINED MAINLY TO COASTAL SECTIONS. INSTABILITY LIMITED BUT CANT
COMPLETELY RULE OUT THUNDERSTORMS. PWS JUST BELOW 2 INCHES SUNDAY
MORNING...BUT QUICKLY DROPS OFF AS SYSTEM MOVES AWAY. AS SYSTEM
LIFTS NORTH OF THE AREA DURING THE DAY SUNDAY...UPPER FLOW WILL
BRIEFLY BECOME ZONAL AHEAD OF NEXT APPROACHING TROUGH.
THIS NEXT SYSTEM WILL PUSH A FRONT AHEAD OF IT THROUGH EASTERN NORTH
CAROLINA EARLY MONDAY. NOT AN AWFUL LOT OF MOISTURE EVIDENT IN THE
MODELS WITH THIS BOUNDARY...AND UPPER LEVEL ENERGY LAGS BEHIND
IT...SO WILL KEEP PRECIPITATION CHANCES LOW. HIGH PRESSURE WILL
QUICKLY BUILD IN BEHIND THE FRONT MONDAY NIGHT. HOWEVER MODELS
DIFFER A BIT AT THIS TIME PERIOD IN THE UPPER LEVEL PATTERN WITH
ECMWF DIGGING A DEEPER UPPER LEVEL TROUGH DOWN THE EAST COAST AND
THE GFSENS BEING NOT AS DEEP. THIS DOESNT APPEAR TO AFFECT THE
SURFACE PATTERN AS MODELS AGREE ON HIGH PRESSURE NORTH OF THE AREA
THROUGH THE REMAINDER OF THE WEEK. MODELS DO HINT AT A WEAK INVERTED
TROUGH ALONG THE COAST LATE IN THE WEEK. CURRENT GRIDS HAVE LOW POPS
AND WILL CONTINUE THAT TREND.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 730 AM SAT...PRED VFR EXPECTED THROUGH THE TAF PERIOD.
A COASTAL TROUGH WILL MOVE INTO EASTERN NC TODAY WITH SFC LOW
PRES LIFTING NORTH ALONG THE SE COAST AND EXPECT VARIABLY CLOUDY
SKIES WITH GREATEST COVERAGE EASTERN SECTIONS. COULD SEE ISOLATED
SHOWERS TODAY AS THE COASTAL TROUGH MOVES INLAND BUT BETTER CHANCE
OF SHOWERS WILL OCCUR TONIGHT AS THE LOW LIFTS NE JUST OFF THE
COAST. COASTAL SITES WILL HAVE THE BETTER CHANCE OF RECEIVING
PRECIP WHILE PGV AND ISO COULD VERY WELL REMAIN DRY. IF HEAVIER
PRECIP DEVELOPS COULD SEE BRIEF REDUCTIONS IN CIGS/VSBYS TO MVFR
OR POSSIBLY IFR. NE FLOW WILL CONTINUE TODAY WITH GUSTS TO AROUND
15 KT POSSIBLE THIS AFTERNOON. GUIDANCE SUGGESTING FOG/STRATUS
POSSIBLE TONIGHT BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN TAFS
ATTM.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 AM SAT...LOW PRESSURE WILL MOVE UP THE COAST THIS
WEEKEND...AND BE OFF THE NORTH CAROLINA COAST BY SUNDAY MORNING.
WILL HAVE SOME MVFR CIGS/VIS SUNDAY IN ASSOCIATED SHOWERS AND LOW
CLOUDS. THIS SYSTEM WILL MOVE AWAY FROM THE AREA LATE SUNDAY AS
ANOTHER SYSTEM APPROACHES FROM THE WEST. NOT TOO MUCH MOISTURE
ASSOCIATED WITH THIS FRONTAL BOUNDARY AND UPPER LEVEL ENERGY STAYS
WEST AS IT MOVES THROUGH EASTERN NORTH CAROLINA MONDAY MORNING. MAY
HAVE ISOLATED MVFR CIGS/VIS IN ANY SHOWERS THAT DEVELOP. HIGH
PRESSURE BUILDS IN BEHIND THE FRONT WITH MAINLY VFR CONDITIONS
EXPECTED MONDAY NIGHT THROUGH WEDNESDAY...HOWEVER MAY HAVE SUB VFR
CONDITIONS IN THE PREDAWN HOURS WITH NORTHEASTERLY FLOW.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 530 AM SAT...EXTENDED THE SCA FOR THE PAMLICO SOUND AND
WATERS SOUTH OF OCRACOKE INLET UNTIL 15Z AS OBS CONTINUE TO SHOW
FREQUENT GUSTS TO 25 KT AND SEAS UP TO 6 FT ACROSS THE COASTAL
WATERS. MOST MODELS STILL TOO QUICK TO BRING DOWN WINDS/SEAS EARLY
THIS MORNING. BLENDED HEAVILY WITH THE RUC FOR WINDS WHICH IS MUCH
STRONGER...AND PERHAPS TOO STRONG...THAN ANY OTHER MODEL BETWEEN
12-18Z...BUT SEEMS TO CAPTURE THE CURRENT CONDITIONS BETTER. IF
THE RUC DOES VERIFY LATER THIS MORNING AN EXPANSION OF TIME AND
AREA FOR THE SCA WILL BE NECESSARY.
PREVIOUS DISCUSSION...STRONG SFC HIGH PRES CONTINUES TO RIDGE
INTO THE REGION EARLY THIS MORNING BRINGING NE FLOW AROUND 10-20
KT WITH MANY AREAS SOUTH OF OREGON INLET SEEING FREQUENT GUSTS TO
AROUND 25 KT. EXPECT WINDS TO GRADUALLY DIMINISH TO AROUND 10-15
KT BY THIS AFTERNOON AS A COASTAL TROUGH MOVES INTO THE REGION
ALLOWING GRADIENTS TO WEAKEN SOME. GRADIENTS EXPECTED TO TIGHTEN
AGAIN TONIGHT...MAINLY AFTER MIDNIGHT...AS THE SFC LOW LIFTS TO
JUST OFF CAPE FEAR BY LATE TONIGHT BRINGING WINDS TO 10-20 KT AND
POSSIBLY GUSTS TO AROUND 25 KT. SEAS REMAIN TRICKY AS MODELS A
FOOT OR TWO UNDERDONE THIS PAST EVENING AND HAVE BEEN TOO QUICK TO
DISSIPATE. SEAS CURRENTLY 4-6 FT AND ARE EXPECTED TO SUBSIDE TO
BELOW SCA CRITERIA SOUTH OF OREGON INLET THIS MORNING AS GRADIENTS
WEAKEN SOME...HOWEVER THE PROLONGED NE FETCH OF WINDS ARE EXPECTED
TO KEEP SEAS ELEVATED UP TO 5-7 FT NORTH OF OREGON INLET THROUGH
THE SHORT TERM. MODELS ALSO INDICATING SEAS REBUILD UP TO 6 FT
SOUTH OF OCRACOKE INLET AFTER MIDNIGHT TONIGHT WITH GRADIENTS
TIGHTENING NEAR THE LOW LIFTING TOWARD THE REGION.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 252 AM SAT...SURFACE WIND WILL BE VARIABLE SUNDAY MORNING AS
LOW PRESSURE MOVES UP THE COAST AND ACROSS THE NORTH CAROLINA
COASTAL WATERS. AM EXPECTING THE LOW PRESSURE TO REMAIN JUST EAST OF
THE WATERS WITH NORTH NORTH WESTERLY FLOW. SPEEDS WILL BE 20 TO 25
KNOTS . IF LOW TRACKS FURTHER WEST...SPEEDS WILL BE LIGHT AND
DIRECTION WILL BE DEPENDENT ON WHERE THE LOW TRACKS. SEA HEIGHTS
WILL REACH SMALL CRAFT ADVISORY CRITERIA OVER MOST OF THE WATERS
WITH UP TO 8 FEET EXPECTED IN THE OUTER WATERS. AS THE LOW MOVES
AWAY FROM THE AREA LATE SUNDAY...WIND SPEED AND SEAS WILL DECREASE
BELOW SMALL CRAFT ADVISORY CRITERIA. DIRECTION WILL TURN
SOUTHWESTERLY SUNDAY NIGHT AHEAD OF NEXT APPROACHING SYSTEM. THIS
FRONT IS EXPECTED TO PASS THROUGH THE WATERS MONDAY AFTERNOON WITH
WIND BECOMING NORTH AND NORTHEASTERLY BEHIND IT AS HIGH PRESSURE
BUILDS IN. GRADIENT BETWEEN THE DEPARTING LOW PRESSURE AND BUILDING
HIGH PRESSURE WILL INCREASE WINDS TO 15 TO 20 KNOTS MONDAY NIGHT
THROUGH WEDNESDAY. MODELS HINTING AS A TROUGH DEVELOPING ALONG THE
COAST LATE WEDNESDAY...WHICH WILL HELP INCREASE WIND SPEEDS
WEDNESDAY NIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ135-
156-158.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR AMZ150-152-154.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...CGG
AVIATION...CGG/SK
MARINE...CGG/SK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
710 AM CDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 707 AM CDT SAT SEP 20 2014
NO CHANGES WERE MADE AS TIMING OF PRECIP SEEMS GOOD BASED ON
LATEST RAP AND 06Z NAM.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 357 AM CDT SAT SEP 20 2014
TO START THE DAY...WILL HAVE SOME LOW CLOUDS IN PARTS OF NW MN AND
PATCHY CLOUDS AND FOG IN NE ND. BIG ISSUE TODAY IS UPSTREAM VORT
MAX IN EAST CENTRAL ALBERTA THAT WILL MOVE SOUTHEAST INTO WESTERN
ND AT 18Z AND THEN INTO WEST CNTRL MN AT 00Z SUN. VERY STRONG MID
AND UPPER LEVEL FORCING WITH A 80 KT 500 MB JET AND 130 KT 300 MB
JET WITH THIS VORT...ALONG WITH STRONG UPPER LEVEL DIVERGENCE
CENTERED OVER THE RED RIVER VALLEY EARLY THIS AFTN. SPC WRF AND
RUC AND LOCAL WFO FGF WRF ALL INDICATE ABOUT THE SAME SCENARIO
WITH A POTENTIAL SQUALL LINE ORGANIZING OVER NE ND NEAR NOON-EARLY
AFTN AND MOVING EAST-SOUTHEAST INTO MINNESOTA EARLY TO MID AFTN.
PEAK OF ACTIVITY VIA RADAR PROGS FROM SPC WRF WOULD INDICATE AREAS
FROM ROSEAU TO DETROIT LAKES IN THE PRIME ZONE THEN LINE WILL MOVE
EAST AND WEAKEN TOWARD 00Z JUST EAST OF THE FCST AREA. SPC DAY 1
HAS MUCH OF THE AREA IN SLIGHT RISK USING THE AFOREMENTIONED
PARAMTERS. ONE DOWNSIDE IS THAT THE LOW LEVELS WILL BE MUCH COOLER
THAN YESTERDAY AND THUS INSTABILITY PARAMETERS WILL BE PRETTY WEAK
WITH BARELY BELOW 0C SHOWWALTERS WITH SYSTEM. IT IS EXPECTED MID
AND UPPER LEVEL DYNAMICS WILL OVERCOME THIS. WIND SEEMS TO BE THE
MAIN THREAT AS 850 MB WINDS INCREASE TO 45 KTS FOR A TIME MID AFTN
JUST EAST OF THE RRV AS LINE MOVES THROUGH. THUS ANY STRONG STORM
LINE COULD EASILY MIX THIS DOWN. HAIL ALSO A THREAT DUE TO COOLING
AT 500 MB WITH SYSTEM AS TEMPS AT THAT LEVEL DROP TO -20C. TORNADO
THREAT WOULD SEEM LOW...DUE TO LACK OF SFC LOW UNLIKE YESTERDAY.
DID INCLUDE SEVERE WORDING FOR A 2-3 HOUR PERIOD ACROSS THE RRV
INTO MN IN RISK AREA BASED ON TIMING FROM SPC WRF/RUC.
SYSTEM CLEARS EAST TONIGHT...LINGERING CLOUDS IN LAKE OF THE
WOODS BUT CLEARING ELSEWHERE. SUNDAY WILL SEE CLOUDS MOST
PROMINENT IN MN FCST AREA UNDER DEPARTING 500 MB TROUGH.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 357 AM CDT SAT SEP 20 2014
SUN NIGHT INTO MONDAY WILL FEATURE GENERALLY CLEAR SKY AS HIGH
PRESSURE AND DRY AIRMASS MOVES IN.
FOR TUESDAY THROUGH FRIDAY...
LONG WAVE RIDGE OVER WESTERN NORTH AMERICA SHIFTS TO EASTERN
NORTH AMERICA BY THE END OF THE PERIOD. LONG WAVE UPPER RIDGE
PRODUCES MUCH ABOVE NORMAL HEIGHTS BY THE END OF THE PERIOD. SHORT
WAVE TROUGH OFF THE CA COAST IS FORECAST TO MOVE ACROSS ITO THE
NORTHERN PLAINS BY LATE TUE INTO WED. THE GFS AND ECMWF ARE
SIMILAR IN TIMING AT 84 HOURS THE GFS BECOMES THE FASTER SOLUTION
ON THU AND FRI. WILL PREFER THE ECMWF.
TWEAKED POPS UP A LITTLE ON TUE.
LITTLE CHANGE TO TEMPS...INCREASE TEMPS BY A DEGREE ON THU.
ESSENTIALLY NO CHANGES FROM PREVIOUS FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 707 AM CDT SAT SEP 20 2014
TYPICAL EARLY MORNING AREA OF LOW END MVFR/IFR CIGS ALONG WITH
PATCHES OF FOG IN THE RED RIVER VALLEY INTO MINNESOTA. THE LOW
CLOUDS/FOG WILL MIX OUT BUT REPLACE BY MID AND HIGH LEVEL MOISTURE
FROM UPPER WAVE MOVING SOUTHEAST. TRIED TO TIME BEST RISK OF TSTMS
AT TAF SITES....MOSTLY VERY LATE MORNING IN DVL AND EARLY AFTN IN
GFK AND MID AFTN TVF-FAR AND LATE AFTN BJI. WINDS MAIN ISSUE WITH
THESE STORMS AS A WEST-SOUTHWEST WIND TURNS NORTHWEST WITH LIKELY
HIGH GUSTS FOR A TIME WITH LINE OF SHOWERS/STORMS. WINDS WILL
DIMINISH THIS EVE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...RIDDLE
LONG TERM...HOPPES/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
647 AM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF TO THE EAST TODAY AS A COLD FRONT
APPROACHES FROM THE NORTHWEST. THE COLD FRONT WILL MOVE ACROSS THE
AREA LATE TONIGHT AND SUNDAY. HIGH PRESSURE WILL THEN BECOME
REESTABLISHED FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MODELS...SUCH AS THE HRRR AND RAP...CONTINUE TO FORECAST
THE DEVELOPMENT OF LOWER LEVEL CLOUDS...4 K FT TO 6 KT ACROSS THE
SRN CWFA TOWARD MORNING. THIS DEVELOPMENT IS DUE TO WEAK
ISENTROPIC LIFT OCCURRING AROUND DEPARTING HIGH PRESSURE. THERE
MAY BE ENOUGH SHALLOW INSTABILITY IN THIS DECK TO WARRANT A LOW
CHANCE POP ALONG AND SOUTH OF THE OHIO RIVER THROUGH THE MORNING
HOURS.
OTHERWISE...WE SHOULD SEE PARTLY TO MOSTLY SUNNY SKIES TODAY OUT
AHEAD OF A COLD FRONT WHICH WILL MAKE IN ROADS TOWARD OUR REGION
TONIGHT. INCREASING SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND
THE FRONT WILL BOOST TEMPERATURES INTO THE UPPER 70S TO THE LOWER
80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HAVE AGAIN USED A BLEND OF THE ECMWF/GFS...ALONG WITH CONVECTION
ALLOWING MODELS...TO HONE IN ON THE PROSPECTS OF PCPN TONIGHT INTO
SUNDAY NIGHT.
A SERIES OF S/WVS WILL DIG EAST/SOUTHEAST THROUGH THE GREAT LAKES
TONIGHT INTO SUNDAY NIGHT...WHICH WILL EVENTUALLY ESTABLISH A LONG
WAVE MID LEVEL TROUGH OVER ERN CANADA SOUTHWARD INTO THE ERN U.S.
BY MONDAY MORNING. THE FIRST WAVE...ALONG WITH PREFRONTAL
CONVERGENCE...IS EXPECTED TO RESULT IN SHOWERS/THUNDERSTORMS TO
OUR NORTHWEST LATE THIS AFTERNOON INTO EARLY THIS EVENING. MODELS
CONTINUE TO SUGGEST THAT AS THIS ACTIVITY PROPAGATES SOUTHEAST INTO
OUR AREA TONIGHT OUT AHEAD OF A COLD FRONT...IT WILL UNDERGO A
WEAKENING TREND. RAPIDLY DECREASING INSTABILITY...WEAKENING LOW
LEVEL FORCING...ALONG WITH WEAKENING UPPER LEVEL SUPPORT ARE THE
REASONS THAT THIS IS FORECAST TO OCCUR. AS A RESULT...HAVE PLACED
THE HIGHEST POPS TONIGHT OVER THE FAR NW...DECREASING THE THREAT
TO JUST 30 AND 40 PERCENT THROUGH THE REMAINDER OF THE REGION
TOWARD SUNDAY MORNING.
ON SUNDAY...ANOTHER EMBEDDED S/WV WILL APPROACH FROM THE NORTHWEST
WHILE THE COLD FRONT PUSHES EAST/SOUTHEAST THROUGH THE REGION.
WITH THE FASTER TIMING OF THE GFS/ECMWF...BELIEVE ANY
SHOWER/THUNDERSTORM REDEVELOPMENT SHOULD OCCUR JUST EAST/SOUTHEAST
OF THE AREA. IN THE WAKE OF THE FRONT...AND BEFORE THE ARRIVAL OF
THE NEXT S/WV...WE SHOULD SEE A POCKET OF DRY WEATHER ALONG WITH
PARTLY TO MOSTLY SUNNY SKIES. HIGHS ON SUNDAY WILL BE TRICKY AS
CAA WILL BE ONGOING THROUGH THE DAY. WILL FORECAST LOWER 70S
NORTHWEST TO THE UPPER 70S SOUTHERN/SOUTHEAST.
FOR SUNDAY NIGHT...AFOREMENTIONED S/WV WILL PASS THROUGH THE
REGION ALONG WITH A SFC TROF AXIS. THERE COULD BE ENOUGH
INSTABILITY WITH THIS FEATURE TO BRING A FEW SPOTTY SHOWERS TO THE
NRN ZONES SUNDAY EVENING. BUT AS TIME WEARS ON AND INSTABILITY
WANES...THE THREAT SHOULD RELEGATE ITSELF TO OUR NE TOWARD
CENTRAL/EASTERN LAKE ERIE. PARTLY CLOUD SKIES WILL UNDERGO A
CLEARING TREND...ESPECIALLY WEST OVERNIGHT. LOWS WILL DROP INTO
THE MID 40S NORTHWEST TO THE LOWER 50S SOUTHEAST.
FOR MONDAY INTO MONDAY NIGHT...MID LEVEL TROUGH WILL MOVE EAST AS
A MID LEVEL RIDGE BUILDS NORTHWARD INTO THE MIDDLE AND UPPER MS
RIVER VALLEY. AT THE SURFACE...A SPRAWLING AREA OF HIGH PRESSURE
WILL BE FOUND AS IT SETTLES RIGHT OVER THE OHIO VALLEY BY TUESDAY
MORNING. CLOUDS WILL CONTINUE TO DECREASE THROUGH THE PERIOD WITH
CLEAR SKIES EXPECTED BY MONDAY NIGHT. AFTER COOL TEMPERATURES
RANGING FROM THE LOWER 60S NORTH TO THE UPPER 60S SOUTH...OVERNIGHT
LOWS WILL DIP INTO THE UPPER 30S AND LOWER 40S BY TUESDAY MORNING.
ON TUESDAY...WITH THE HIGH REMAINING IN PLACE...SKIES WILL BE
SUNNY. HIGHS WILL WARM INTO THE UPPER 60S TO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH
THE LONG TERM. TEMPERATURES WILL SLOWLY WARM THROUGH THE LONG
TERM WITH HIGH TEMPERATURES BY FRIDAY EXPECTED TO BE IN THE MID TO
UPPER 70S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
ALTHOUGH THE MAJORITY OF THE FORECAST PERIOD IS EXPECTED TO BE
VFR...THERE ARE A FEW ITEMS TO DISCUSS. ALTHOUGH ANY REMAINING
MVFR VISIBILITY RESTRICTIONS WILL BE SHORT-LIVED...AN INCREASE IN
MOISTURE FROM THE SOUTH WILL RESULT IN SCATTERED TO BROKEN CLOUDS
OVER THE REGION...GENERALLY IN THE 3500-6000 FOOT RANGE. SOUTHERLY
FLOW WILL SWITCH TO THE SOUTHWEST...WITH GUSTS IN THE 18-22 KNOT
RANGE BY EARLY AFTERNOON.
A COLD FRONT IS FORECAST TO APPROACH THE REGION FROM THE NORTHWEST
TONIGHT AND INTO SUNDAY MORNING. AHEAD OF THIS
FRONT...PRECIPITATION IS FORECAST TO MOVE INTO THE AREA LATE THIS
EVENING AND INTO THE EARLY MORNING HOURS. HOWEVER...THE EXTENT OF
PRECIPITATION WITH THIS FRONT IS NOT CERTAIN. THE PRECIPITATION
(WHICH COULD INCLUDE THUNDERSTORMS) SHOULD BE ON A WEAKENING TREND
AS IT MOVES THROUGH THE TAF SITES. A TEMPO -SHRA GROUP WAS
INCLUDED AT KDAY...BUT THE OTHER TAF SITES ARE NOT AS CERTAIN TO
RECEIVE RAIN. AS THE FRONT NEARS...CEILINGS ARE EXPECTED TO DROP
INTO THE MVFR RANGE.
OUTLOOK...A FEW SHOWERS...AND POSSIBLY A THUNDERSTORM...WILL BE
POSSIBLE DURING THE FIRST HALF OF SUNDAY. MVFR CEILINGS ARE ALSO
POSSIBLE ON SUNDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
659 AM CDT SAT SEP 20 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT SAT SEP 20 2014
MAIN CONCERNS ARE ON EXITING MORNING CONVECTION AND THE RETURN FOR
MORE CONVECTION TONIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW JUST OFF THE CALIFORNIA COAST...RIDGING OVER THE
WESTERN THIRD OF THE U.S. INTO BRITISH COLUMBIA...AND TROUGHING OVER
CENTRAL CANADA INTO THE NORTHERN PLAINS/UPPER MIDWEST. A COUPLE OF
SHORTWAVES TRAVERSING THROUGH THIS TROUGH IN SOUTH DAKOTA AND MN...
COMBINED WITH A SURFACE TO 850MB COLD FRONT THAT STRETCHED FROM
DULUTH TO SIOUX CITY IA...HAVE AIDED IN MAINTAINING A BAND OF
SHOWERS AND THUNDERSTORMS. THIS BAND EXTENDS FROM WEST CENTRAL IA
THROUGH THE FORECAST AREA. MUCH OF THE ACTIVITY HAS BEEN ELEVATED IN
NATURE DUE TO CAPPING PRESENT OF BL PARCELS. PLENTY OF INSTABILITY
FOR THE CONVECTION WITH CAPE VALUES LIFTED FROM 1 KM BETWEEN 1000-
2000 J/KG. IN THE WAKE OF THE CONVECTION...THERE HAS BEEN A NARROW
AREA OF LOW STRATUS DEVELOPING...BEFORE CLOUDS CLEAR OUT OVER
CENTRAL MN. AIRMASS BEHIND THE COLD FRONT WAS NOT MUCH COLDER THAN
AHEAD...WITH 925MB TEMPS HOVERING BETWEEN 20-24C. HOWEVER...
PRECIPITABLE WATER DROPS SIGNIFICANTLY FROM 1.5-1.75 INCHES TO 1-
1.25 INCHES. UPSTREAM A MORE SIGNIFICANT COLD FRONT EXISTS OVER
NORTHERN NORTH DAKOTA AND NORTHWEST MN WHERE 925MB TEMPS DROP TO 12-
14C.
THE COLLECTION OF SHORTWAVES ACROSS SOUTH DAKOTA AND MN ARE PROGGED
TO CROSS THE FORECAST AREA THIS MORNING...PUSHING THE SURFACE-850MB
COLD FRONT THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z. ANTICIPATING
MUCH OF THE CURRENT CONVECTION AHEAD OF THESE FEATURES TO MARCH
SOUTHEASTWARD OUT OF THE FORECAST AREA BY 13Z PER HIGH RESOLUTION
MODEL CONSENSUS. STILL CARRIED SOME LOW PRECIPITATION CHANCES OVER
THE SOUTHEAST HALF IN THE WAKE OF THE CURRENT ACTIVITY IN THE EVENT
ADDITIONAL SHOWERS/STORMS FORM AS THE SHORTWAVES MOVE IN.
OTHERWISE...SUBSIDENCE AND DRYING OF PRECIPITABLE WATER SHOULD ALLOW
SKIES TO CLEAR AFTER A BRIEF PERIOD OF MORNING STRATUS. THE SUNSHINE
COMBINED WITH 925MB TEMPS OF 18-20C FOR MUCH OF TODAY SHOULD ALLOW
FOR HIGHS TO TOP OUT IN THE 70S IN MOST LOCATIONS...WITH SOME LOW
80S IN VALLEYS.
SHORTLY AFTER 00Z THIS EVENING...ANOTHER LINE OF SHOWERS AND
EMBEDDED THUNDERSTORMS LOOKS LIKELY TO MOVE ACROSS THE REGION...
ESPECIALLY ALONG AND NORTH OF I-90. THIS LINE OF CONVECTION WILL BE
FORCED BY A POTENT SHORTWAVE OVER CENTRAL ALBERTA DROPPING THROUGH
THE UPPER MIDWEST TROUGHING. THE SHORTWAVE SHOULD ALSO HAVE A NARROW
CORRIDOR OF MOISTURE TO WORK WITH AS PRECIPITABLE WATER JUMPS UP TO
1-1.3 INCHES. INSTABILITY WISE...ITS FAIRLY MEAGER WITH VALUES OF
100-500 J/KG...MOSTLY IN THE EVENING DUE TO LOSS OF DAYTIME HEATING
COOLING THE BOUNDARY LAYER. ANTICIPATING MORE THUNDERSTORM ACTIVITY
SHOULD OCCUR TODAY UPSTREAM OVER NORTH DAKOTA INTO CENTRAL MN WHERE
THE JUXTAPOSITION OF HIGHER DIURNALLY BASED INSTABILITY INTERSECTS
THE SHORTWAVE. SHEAR PROFILES WOULD CERTAINLY SUPPORT BOTH A
DAMAGING WIND AND LARGE HAIL THREAT WITH CONVECTION...HOWEVER...THE
MEAGER INSTABILITY BY THE TIME THE CONVECTION MOVES INTO THE
FORECAST AREA SHOULD HELP MITIGATE SEVERE POTENTIAL. MAY STILL SEE
SOME STRONGER WIND GUSTS...THOUGH. HAVE RAISED PRECIPITATION CHANCES
UP FOR THE EVENING HOURS GIVEN VERY GOOD MODEL CONSENSUS FOR THIS
CONVECTION. KEPT SOME PRECIPITATION CHANCES GOING OVERNIGHT TOO
ALONG AND NORTH OF I-94 WHERE A FRONTOGENESIS BAND LOOKS TO SETUP ON
THE NORTH SIDE OF THE SHORTWAVE. LOOK FOR COOLER TEMPERATURES
TONIGHT AS COLDER AIR RUSHES IN BEHIND THE LINE OF CONVECTION. IN
FACT...925MB TEMPS COOL AS MUCH AS 10C ON A BRISK 30-40 KT 925MB
NORTHWEST WIND.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM CDT SAT SEP 20 2014
MAIN CONCERNS ARE ON PRECIPITATION POTENTIAL FOR SUNDAY...FOLLOWED
BY TEMPERATURES AND VALLEY FOG POTENTIAL SUNDAY NIGHT AND BEYOND.
ANOTHER POTENT SHORTWAVE LOOKS TO FOLLOW QUICKLY ON THE HEELS OF THE
ONE MOVING THROUGH THE FORECAST AREA TONIGHT. THIS SHORTWAVE...
CURRENTLY IN NORTHERN SASKATCHEWAN...IS PROGGED TO DROP SOUTH
THROUGH THE FORECAST AREA SUNDAY MORNING. THIS SHORTWAVE WILL HELP
TO PULL THE FRONTOGENESIS BAND AND ASSOCIATED SURFACE COLD FRONT
SOUTHWARD THROUGH THE FORECAST AREA DURING THE MORNING HOURS.
APPEARS THE BULK OF THE RAIN/SHOWER ACTIVITY WITH THE BAND WILL BE
CONFINED TO WISCONSIN...BUT SOME MAY EVEN CREEP ACROSS THE MS RIVER
AS SUGGESTED BY THE 20.00Z ECMWF/CANADIAN. HAVE RAISED PRECIPITATION
CHANCES UPWARDS AND FURTHER INCREASES MAY BE NECESSARY. OVERALL
AMOUNTS LOOK TO BE FAIRLY LIGHT...THOUGH. THIS FRONTAL BOUNDARY
DROPPING SOUTH...925MB TEMPS ONLY TOPPING OUT FROM 10-12C AT 00Z
MONDAY...A BREEZY NORTH WIND AND A DECENT AMOUNT OF SUN NOT
OCCURRING UNTIL LATE IN THE DAY WILL YIELD MUCH COOLER CONDITIONS
COMPARED TO TODAY.
MODELS REMAIN IN GOOD AGREEMENT IN BUILDING HIGH PRESSURE INTO THE
FORECAST AREA FOR SUNDAY NIGHT THROUGH TUESDAY. THIS IS IN RESPONSE
TO THE UPPER RIDGE OVER THE WESTERN THIRD OF THE U.S. MARCHING EAST
INTO MN AND IA BY 12Z TUE. THE MAIN CENTER OF THE HIGH LOOKS TO
TRACK JUST SOUTH OF THE AREA...BUT THE GRADIENT RELAXES ENOUGH TO
ALLOW FOR DECOUPLING BOTH NIGHTS. SOME CLOUDS COULD DRIFT ACROSS
BOTH NIGHTS...BUT IT APPEARS ENOUGH PERIOD OF CLEAR SKIES SHOULD
EXIST FOR VALLEY FOG TO FORM...ESPECIALLY IN THE TRIBUTARIES. SUNDAY
NIGHT WILL BE THE COOLER OF THE TWO NIGHTS DUE TO AIRMASS
MODIFICATION TAKING PLACE ON MONDAY. THE TYPICAL COLD SPOTS IN
CENTRAL WI COULD DIP INTO THE MID/UPPER 30S SUNDAY NIGHT. 925MB
TEMPS OF 12-14C ON MONDAY WITH MORE SUN WILL ALLOW HIGHS TO TOP OUT
IN THE 60S TO LOW 70S...WARMEST IN VALLEYS. THESE 925MB TEMPS CLIMB
ANOTHER 1-2C ON TUESDAY...RESULTING IN A SIMILAR BUMP UP IN HIGHS.
IN GENERAL THE WEATHER REMAINS FAIRLY QUIET FROM TUESDAY NIGHT RIGHT
INTO NEXT WEEKEND...THANKS TO SIGNIFICANT UPPER RIDGING BUILDING UP
OVER THE EASTERN TWO THIRDS OF THE U.S.. IN FACT...MOST LONG RANGE
GUIDANCE IS SUGGESTING A 590 DAM 500MB HIGH TO FORM OVER MICHIGAN BY
00Z SATURDAY...WHICH WOULD BE ABOUT 2 STANDARD DEVIATIONS ABOVE
NORMAL. THIS IS ALL A RESULT OF A VERY DEEP TROUGH DEVELOPING ALONG
THE WEST COAST OF THE U.S....SOMETHING THAT HASNT BEEN SEEN FOR
QUITE SOME TIME. THE ONLY REAL ISSUE TO WORRY ABOUT IS THE CURRENT
UPPER LOW OFF THE CALIFORNIA COAST...WHICH MODELS TRY TO BRING
THROUGH THE FORECAST AREA IN A WEAKENING STATE CENTERED AROUND
WEDNESDAY. HAVE MAINTAINED SOME LOW PRECIPITATION CHANCES ASSOCIATED
WITH THIS FEATURE. DESPITE THE RISING 500MB HEIGHTS...IT TAKES
AWHILE FOR A SIMILAR RESPONSE TO 850MB TEMPS...PARTIALLY DUE TO THAT
UPPER LOW LIFTING THROUGH. THUS...TEMPERATURES HOLD NEAR SEASONABLE
NORMALS UNTIL THE END OF THE WEEK. FRIDAY...SATURDAY AND SUNDAY ALL
LOOK ABOVE NORMAL WITH HIGHS POSSIBLY APPROACHING 80.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 658 AM CDT SAT SEP 20 2014
SCATTERED SHOWERS AHEAD OF A COLD FRONT WILL AFFECT KRST THROUGH
20.16Z. THE MESO MODELS SUGGEST THAT THESE SHOWERS WILL NOT MAKE
IT INTO KLSE. HOWEVER WITH WEAK 700 MB MOISTURE TRANSPORT INTO THE
AREA BETWEEN 20.15Z AND 20.18Z...MAY HAVE TO RECONSIDER ADDING
THEM TO THE TAF LATER THIS MORNING. AFTER THE PASSAGE OF THIS
FRONT...IT WILL REMAIN DRY WITH VFR CEILINGS AND VISIBILITIES
THROUGH THIS AFTERNOON.
ANOTHER COLD FRONT WILL MOVE THROUGH THE TAF SITES THIS EVENING.
IT WILL MOVE THROUGH KRST BETWEEN 21.01Z AND 21.03Z...AND KLSE
BETWEEN 21.02Z AND 21.04Z. CEILINGS WILL DROP TO 5K FEET DURING
THIS TIME PERIOD. VISIBILITIES MAY BECOME BRIEFLY MVFR IN SHOWERS.
FOR LATE TONIGHT...THE MODEL SUGGEST THAT A MVFR STRATUS DECK MAY
DEVELOP. HOWEVER WITH DRY AIR LOCATED ACROSS REGION...A BIT
CONCERNED THAT THE MODELS MAY BE OVER DOING THIS...SO OPTED NOT
PUTTING THESE CLOUDS IN THE TAFS AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
340 PM MST SAT SEP 20 2014
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.
&&
.SYNOPSIS...
LINGERING MOISTURE ACROSS THE REGION AND LOW PRESSURE APPROACHING
FROM THE WEST WILL KEEP AT LEAST SLIGHT CHANCES FOR SHOWERS AND
THUNDERSTORMS FOR TODAY. DRIER AIR WILL GRADUALLY FILTER
INTO THE REGION SUNDAY AND MONDAY FOR A DECLINE IN STORM CHANCES.
SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE
HIGHER MOUNTAINS OF SOUTH-CENTRAL ARIZONA DURING THE MIDDLE OF NEXT
WEEK WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. AN APPROACHING
PACIFIC WEATHER SYSTEM LATE NEXT WEEK WILL LEAD TO AN INCREASE IN
STORM CHANCES.
&&
.DISCUSSION...
MODEL THETA-E GRADIENT ALIGNED WELL WITH THE FAVORABLE LOCATIONS OF
HIGHER MOISTURE CONTENT AND GREATER INSTABILITY. THE RAP MLCAPE
VALUES JUST OVER 1500 J/KG ALONG AN AXIS FROM NOGALES TO BULLHEAD
CITY. WESTERN MARICOPA COUNTY...LA PAZ AND NORTHERN YUMA COUNTIES
LOOK TO BE THE FAVORABLE AREAS FOR CONVECTION THIS AFTERNOON AND
EVENING. CAN NOT RULE OUT ISOLATED STORMS SNEAKING IN TO NORTHERN
PINAL COUNTY FROM SOUTH-CENTRAL ARIZONA...AS THE GREATER TUCSON AREA
HAS BEEN INCREASING IN ACTIVITY LATE THIS MORNING. PRECIPITABLE
WATER VALUES HOVERING AROUND 1.5 INCHES ACROSS THE LOWER DESERTS AND
A VERY BROAD DIFLUENT MID-LAYER STRETCHING NORTH-NORTHWEST THROUGH
THE GREAT BASIN ALLOWS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON AND
EVENING. MOISTURE AND DYNAMICS ARE IN PLACE AND THE POTENTIAL ENERGY
IS THERE...NOW THE CHALLENGE WILL BE FOR A TRIGGER TO PUSH THE
DEVELOPMENT NEEDED FOR THUNDERSTORM DEVELOPMENT.
STORM CHANCES WILL BE ON THE DECLINE THROUGH MONDAY BEFORE COMING TO
A QUIET HOLDING PATTERN THROUGH THE WEEK. MONSOON MOISTURE LOOKS TO
HANG AROUND THIS WEEK BUT MAINLY ACROSS EASTERN ARIZONA. THE UPPER
LEVEL DISTURBANCE IS PROGGED TO MOVE NORTH THROUGH THE GREAT BASIN
BY MONDAY AND WILL ALLOW A WESTERLY FLOW TO SETTLE IN PLACE OVER THE
SOUTHWEST DESERTS AS WELL AS A DRYING TREND. WILL KEEP SLIGHT CHANCE
MENTION IN ZONE 24 FOR THE HIGHER TERRAIN LOCATIONS. TEMPERATURES
WILL HAVE LITTLE DAY TO DAY CHANGE...REMAINING AT OR A FEW DEGREES
ABOVE SEASONAL NORMAL WITH HIGH PRESSURE DOMINATING THE REGION
THROUGH MID WEEK.
THURSDAY THROUGH SATURDAY...ATTENTION THEN TURNS TO A POSSIBLE
SEASONAL TRANSITION SYSTEM FOR LATE WEEK INTO NEXT WEEKEND.
CONFIDENCE IS STILL NOT VERY HIGH ON THE SPECIFICS OF THE SYSTEM BUT
THE 00Z OPERATIONAL MODELS HAVE COME IN CLOSER AGREEMENT THAT A DEEP
PACIFIC TROUGH WILL SLIDE THROUGH CALIFORNIA ON FRIDAY AND POSSIBLY
AS FAR SOUTH AS ARIZONA SOMETIME NEXT WEEKEND. WIDESPREAD SLIGHT
CHANCE POPS ARE IN THE FORECAST FOR FRIDAY. EITHER WAY IT IS FAIRLY
LIKELY THIS LOW WILL USER IN COOLER AND MUCH DRIER AIR...AND
POTENTIALLY END OUR MONSOON SEASON.
&&
.AVIATION...
SOUTH-CENTRAL AND SOUTHWEST ARIZONA INCLUDING KPHX...KIWA...KSDL...
ISOLATED TO WIDELY SCATTERED THUNDERSTORM ACTIVITY WILL PERSIST THIS
AFTERNOON AND EVENING OVER SOUTH-CENTRAL AZ...A FEW STORMS COULD
BRIEFLY IMPACT LOW DESERT TERMINALS WITH GUSTY OUTFLOWS UP TO 40
KT...AND REDUCED VISIBILITY DOWN TO 3SM IN BLDU. EXPECT SCT-BKN
CLOUD DECKS AOA 7000FT TO PERSIST OVERNIGHT TIMES INTO SUNDAY
MORNING. ONCE POTENTIAL FOR OUTFLOW BOUNDARIES DIMINISHES AFTER
04Z...WINDS WILL GENERALLY BE LIGHT...LESS THAN 10KT AND FAVOR THE
EAST SOUTHEAST AT ALL TERMINALS.
SOUTHEAST CALIFORNIA INCLUDING KIPL...AND KBLH...
OTHER THAN A FEW CLOUDS GENERALLY AOA 10KFT...EXPECT MOSTLY CLEAR
SKIES AND LIGHT WINDS OVERNIGHT THROUGH AT LEAST 18Z SUNDAY
AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
MOISTURE RETREAT DUE TO WESTERLY FLOW WILL KEEP STORM CHANCES
MINIMAL THROUGH THURSDAY AND LIMITED TO THE HIGHER MOUNTAINS OF
SOUTH-CENTRAL ARIZONA. MEANWHILE...TEMPERATURES NUDGE UPWARD A FEW
DEGREES ABOVE NORMAL. HUMIDITIES ON THE LOWER DESERTS DROP BELOW 15
PERCENT THOUGH MAX HUMIDITIES REMAIN FAIR. NO STRONG WINDS ARE
EXPECTED DURING THIS TIME FRAME. ON FRIDAY...A PACIFIC WEATHER
SYSTEM WILL PULL MOISTURE NORTHWARD OVER THE REGION FOR A RETURN OF
STORM CHANCES INTO NEXT WEEKEND...MAINLY EAST OF THE LOWER COLORADO
RIVER VALLEY. IN ADDITION...COOLER TEMPERATURES AND BREEZY TO
LOCALLY WINDY CONDITIONS CAN BE EXPECTED AS WELL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...DEWEY
AVIATION...MEYERS
FIRE WEATHER...MEYERS/AJ
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
205 PM MST SAT SEP 20 2014
.SYNOPSIS...
LINGERING MOISTURE ACROSS THE REGION AND LOW PRESSURE APPROACHING
FROM THE WEST WILL KEEP AT LEAST SLIGHT CHANCES FOR SHOWERS AND
THUNDERSTORMS FOR TODAY. DRIER AIR WILL GRADUALLY FILTER
INTO THE REGION SUNDAY AND MONDAY FOR A DECLINE IN STORM CHANCES.
SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE
HIGHER MOUNTAINS OF SOUTH-CENTRAL ARIZONA DURING THE MIDDLE OF NEXT
WEEK WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. AN APPROACHING
PACIFIC WEATHER SYSTEM LATE NEXT WEEK WILL LEAD TO AN INCREASE IN
STORM CHANCES.
&&
.DISCUSSION...
MODEL THETA-E GRADIENT ALIGNED WELL WITH THE FAVORABLE LOCATIONS OF
HIGHER MOISTURE CONTENT AND GREATER INSTABILITY. THE RAP MLCAPE
VALUES JUST OVER 1500 J/KG ALONG AN AXIS FROM NOGALES TO BULLHEAD
CITY. WESTERN MARICOPA COUNTY...LA PAZ AND NORTHERN YUMA COUNTIES
LOOK TO BE THE FAVORABLE AREAS FOR CONVECTION THIS AFTERNOON AND
EVENING. CAN NOT RULE OUT ISOLATED STORMS SNEAKING IN TO NORTHERN
PINAL COUNTY FROM SOUTH-CENTRAL ARIZONA...AS THE GREATER TUCSON AREA
HAS BEEN INCREASING IN ACTIVITY LATE THIS MORNING. PRECIPITABLE
WATER VALUES HOVERING AROUND 1.5 INCHES ACROSS THE LOWER DESERTS AND
A VERY BROAD DIFLUENT MID-LAYER STRETCHING NORTH-NORTHWEST THROUGH
THE GREAT BASIN ALLOWS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON AND
EVENING. MOISTURE AND DYNAMICS ARE IN PLACE AND THE POTENTIAL ENERGY
IS THERE...NOW THE CHALLENGE WILL BE FOR A TRIGGER TO PUSH THE
DEVELOPMENT NEEDED FOR THUNDERSTORM DEVELOPMENT.
STORM CHANCES WILL BE ON THE DECLINE THROUGH MONDAY BEFORE COMING TO
A QUIET HOLDING PATTERN THROUGH THE WEEK. MONSOON MOISTURE LOOKS TO
HANG AROUND THIS WEEK BUT MAINLY ACROSS EASTERN ARIZONA. THE UPPER
LEVEL DISTURBANCE IS PROGGED TO MOVE NORTH THROUGH THE GREAT BASIN
BY MONDAY AND WILL ALLOW A WESTERLY FLOW TO SETTLE IN PLACE OVER THE
SOUTHWEST DESERTS AS WELL AS A DRYING TREND. WILL KEEP SLIGHT CHANCE
MENTION IN ZONE 24 FOR THE HIGHER TERRAIN LOCATIONS. TEMPERATURES
WILL HAVE LITTLE DAY TO DAY CHANGE...REMAINING AT OR A FEW DEGREES
ABOVE SEASONAL NORMAL WITH HIGH PRESSURE DOMINATING THE REGION
THROUGH MID WEEK.
THURSDAY THROUGH SATURDAY...ATTENTION THEN TURNS TO A POSSIBLE
SEASONAL TRANSITION SYSTEM FOR LATE WEEK INTO NEXT WEEKEND.
CONFIDENCE IS STILL NOT VERY HIGH ON THE SPECIFICS OF THE SYSTEM BUT
THE 00Z OPERATIONAL MODELS HAVE COME IN CLOSER AGREEMENT THAT A DEEP
PACIFIC TROUGH WILL SLIDE THROUGH CALIFORNIA ON FRIDAY AND POSSIBLY
AS FAR SOUTH AS ARIZONA SOMETIME NEXT WEEKEND. WIDESPREAD SLIGHT
CHANCE POPS ARE IN THE FORECAST FOR FRIDAY. EITHER WAY IT IS FAIRLY
LIKELY THIS LOW WILL USER IN COOLER AND MUCH DRIER AIR...AND
POTENTIALLY END OUR MONSOON SEASON.
&&
.AVIATION...
SOUTH-CENTRAL AND SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA
INCLUDING KPHX...KIWA...KSDL...KIPL...AND KBLH...
AN UPPER LOW CENTERED OFF THE COAST OF SOUTHERN CALIFORNIA WILL PULL
MONSOON MOISTURE NORTHWARD TODAY FOR SCT-BKN080-100 WITH SCATTERED
SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN NORTH...EAST...AND
SOUTH...OF THE PHOENIX AREA AND ISOLATED ELSEWHERE. ONSET OF SHOWERS
POSSIBLE BEFORE 18Z. CONFIDENCE TOO LOW AN ANY GIVEN TAF SITE TO
INSERT TEMPO SHWRS/TSTMS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
MOISTURE RETREAT DUE TO WESTERLY FLOW WILL KEEP STORM CHANCES
MINIMAL THROUGH THURSDAY AND LIMITED TO THE HIGHER MOUNTAINS OF
SOUTH-CENTRAL ARIZONA. MEANWHILE...TEMPERATURES NUDGE UPWARD A FEW
DEGREES ABOVE NORMAL. HUMIDITIES ON THE LOWER DESERTS DROP BELOW 15
PERCENT THOUGH MAX HUMIDITIES REMAIN FAIR. NO STRONG WINDS ARE
EXPECTED DURING THIS TIME FRAME. ON FRIDAY...A PACIFIC WEATHER
SYSTEM WILL PULL MOISTURE NORTHWARD OVER THE REGION FOR A RETURN OF
STORM CHANCES...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY. IN
ADDITION...COOLER TEMPERATURES AND BREEZY TO LOCALLY WINDY
CONDITIONS CAN BE EXPECTED AS WELL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...DEWEY
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
234 PM MDT SAT SEP 20 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1224 PM MDT SAT SEP 20 2014
MDLS CONTINUE TO MOISTEN UP THE AIRMASS OVERNIGHT AND SUNDAY. FOR
THIS EVENING...THE LATEST HRRR APPEARS TO KEEP ANY DEVELOPING
THUNDERSTORMS IN THE MOUNTAINS WEST AND SOUTHWEST OF DENVER. THE
AIRMASS REMAINS TOO DRY AND STABLE ELSEWHERE TO SUPPORT ANY DEEP
CONVECTION. THE UPPER RIDGE WILL REMAIN OVER EASTERN COLORADO
TONIGHT...WITH LOW LEVEL ESELY SFC WINDS. THE UPPER LOW WILL BE
OVER SWRN NV SUNDAY MORNING AND WILL MOVE SLOWLY INTO NERN NV BY
00X MONDAY. THE QG ASCENT THROUGH THE PERIOD WILL BE WEAK BUT
PRECIPITABLE WATER VALUES WILL CLIMB BACK OVER AN INCH. WITH THE
COOLER AMS IN PLACE...LIMITED HEATING COUPLED WITH WEAK FORCING
ALOFT SHOULD ALLOW FOR MORE SHOWERS VS THUNDERSTORMS IN THE
FORECAST. WL CONTINUE WITH SCT-LIKELY POPS ACROSS THE MOUNTAINS
AND FOOTHILLS WITH MORE EMPHASIS ON SHOWERS IN THE GRIDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT SEP 20 2014
NOT A LOT OF DIFFERENCE IN THE MODEL SOLUTIONS DURING THE PERIOD.
THE UPPER LOW CURRENTLY WEST OF LOS ANGELES IS PREDICTED TO LIFT
TO THE NORTHEAST WITH ITS ASSOCIATED TROUGH PASSING EAST OF THE
STATE TUESDAY MORNING. THE RESULT OF THIS IS A QUANTITATIVELY
MODEST BUT DEEP AND PROLONGED PERIOD OF QUASIGEOSTROPHIC ASCENT
OVER MOST OF THE AREA BEGINNING TONIGHT AND CONTINUING THROUGH
MONDAY NIGHT. THIS ASCENT SHOULD DIMINISH FROM WEST TO EAST DURING
THE DAY TUESDAY AS UPPER LEVEL RIDGING OCCURS OVER THE CENTRAL
ROCKIES. CONSEQUENTLY EVERYONE SHOULD HAVE A SHOT AT SOME
PRECIPITATION AS THIS SYSTEM PASSES BY EARLY IN THE PERIOD WITH
DRIER CONDITIONS EXPECTED AFTER TUESDAY. PRECIPITABLE WATER
VALUES ARE FORECAST TO EXCEED 1.00 INCH WITH THIS SYSTEM AND WITH
MODERATE CAPE VALUES AROUND AT TIMES THE THREAT OF SOME HEAVY
SHOWERS CANNOT BE COMPLETELY RULED OUT IN THE SUNDAY NIGHT THROUGH
TUESDAY MORNING TIME FRAME. AT PRESENT HOWEVER IT IS DIFFICULT TO
SINGLE OUT ANY PARTICULAR AREA FOR ANY ENHANCED FLOODING THREAT.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z SUNDAY LATE AFTERNOON)
ISSUED AT 1224 PM MDT SAT SEP 20 2014
VFR CIGS/VSBYS THROUGH 06Z...THE AMS DOES MOISTEN UP OVERNIGHT
WITH LCL LOWERING ENOUGH TO PRODUCE ILS APPROACHES WITH OCNL BKN-
OVC CIGS OF 050-060 KFT AGL AFTER 06Z. ISOLD RAIN SHOWERS POSSIBLE
SUNDAY MORNING...WITH BETTER POTENTIAL FOR SHOWERS ALONG THE
FOOTHILLS ON SUNDAY. COOLER AMS WL KEEP THE POTENTIAL FOR TSTMS ON
THE LOW SIDE...WITH A BETTER CHC FOR RAIN SHOWERS SUNDAY AFTN.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM...ET
AVIATION...COOPER
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
443 PM EDT SAT SEP 20 2014
.UPDATE...
MOST OF THE SHOWERS AND THUNDERSTORMS THAT BEEN OCCURRING OVER THE
EASTERN AREAS OF SOUTH FLORIDA HAVE PUSHED INTO THE ATLANTIC
WATERS LATE THIS AFTERNOON. THE ONLY AREA THAT COULD STILL SEE
SOME SHOWERS AND THUNDERSTORMS IS OVER MIAMI-DADE COUNTY AS THIS
AREA HAS NOT BEEN WORK OVER YET TODAY. THEREFORE...THE POPS HAVE
BEEN LOWERED OVER MOST OF SOUTH FLORIDA...EXCEPT FOR THE SOUTHEAST
AREAS OF SOUTH FLORIDA WHERE SCATTERED POPS WILL REMAIN IN PLACE
FOR THIS AFTERNOON. FOR THE ATLANTIC WATERS...THE POPS HAVE ALSO
BEEN RAISED TO NUMEROUS COVERAGE FOR THE ON GOING SHOWER AND
THUNDERSTORM ACTIVITY.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED.
&&
.UPDATED...54/BNB
.PREV DISCUSSION... /ISSUED 326 PM EDT SAT SEP 20 2014/
DISCUSSION...
THE SUN CAME OUT THIS AFTERNOON ACROSS THE SOUTHEASTERN PORTION OF
THE REGION...AND TEMPERATURES WERE ABLE TO GET BRIEFLY INTO THE
UPPER 80S TO AROUND 90 DEGREES. SHOWERS AND STORMS WERE BEGINNING
TO FILL IN ACROSS THE EAST COAST METRO AREAS...AND NUMEROUS TO
WIDESPREAD SHOWERS AND ISOLATED/SCATTERED STORMS WILL CONTINUE
ACROSS SOUTH FLORIDA THROUGH THE AFTERNOON HOURS. THE MAIN THREAT
THIS AFTERNOON WILL BE LOCALLY HEAVY RAINFALL AND ISOLATED STREET
FLOODING FOR THE EAST COAST METROS. GUSTY WINDS UP TO 50 MPH ARE
ALSO POSSIBLE.
TONIGHT...SHOWERS AND STORMS WILL DIMINISH SLOWLY THIS EVENING
WITH LOSS OF DAYTIME HEATING...BUT REDEVELOPMENT IS POSSIBLE
OVERNIGHT FOR THE GULF WATERS THROUGH THE NAPLES REGION. THE AREA
OF LOW PRESSURE OFF THE EAST COAST OF NORTH FLORIDA WILL MOVE
NORTHEAST OVERNIGHT...BUT THE FRONTAL BOUNDARY ACROSS CENTRAL
FLORIDA WILL REMAIN STATIONARY.
SUNDAY AND MONDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH
FLORIDA TO THE SOUTH OF THE BOUNDARY ACROSS CENTRAL FLORIDA...WITH
PWATS AROUND 2 INCHES. WEAK UPPER TROUGHING WILL ALSO CONTINUE
ACROSS THE REGION. A FEW MID LEVEL IMPULSES SLIGHTLY DETACHED
FROM THE PARENT 500MB SHORTWAVE WELL TO THE NORTH ARE EXPECTED TO
SLIDE TO THE NORTHEAST ACROSS THE NORTHERN INTERIOR. THIS SHOULD
ENHANCE THUNDERSTORM DEVELOPMENT OVER THE AREA FOR THROUGH THE
BEGINNING OF NEXT WEEK. NUMEROUS SHOWERS AND STORMS ARE EXPECTED
EACH AFTERNOON.
A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST
THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES
FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE
DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS
DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE
REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER
ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO
SEVERE THUNDERSTORM POTENTIAL LIMITED.
AVIATION...
SCATTERED SHOWERS AND STORMS ASSOCIATED WITH A FRONTAL BOUNDARY
AND UPPER TROUGH WILL CONTINUE TO DEVELOP AND INCREASE IN
COVERAGE ACROSS THE AREA THROUGH THE AFTERNOON HOURS. WSW FLOW
WILL FOCUS THE HEAVIEST ACTIVITY TOWARD THE EAST COAST SITES
THROUGH THIS TIME TODAY. THE FLOW SHOULD PROVE TO BE TOO STRONG
FOR THE EAST COAST SEA BREEZE TO SET UP...WHICH IS REFLECTED WELL IN
THE LATEST HRRR RUN THAT INDICATES THE ACTIVITY PUSHING THROUGH
AND OFF THE COAST THROUGH THE EARLY EVENING PERIOD. VFR CONDITIONS
SHOULD RETURN THROUGH THE LATE EVENING AND OVERNIGHT HOURS WITH
LIGHT WESTERLY FLOW CONTINUING. 85/AG
MARINE...
GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD
PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO
THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP
THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS
ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET
OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 88 75 86 / 40 50 20 60
FORT LAUDERDALE 75 88 78 87 / 40 60 20 60
MIAMI 74 88 77 87 / 40 60 20 60
NAPLES 75 87 75 86 / 50 50 20 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
326 PM EDT SAT SEP 20 2014
.DISCUSSION...
THE SUN CAME OUT THIS AFTERNOON ACROSS THE SOUTHEASTERN PORTION OF
THE REGION...AND TEMPERATURES WERE ABLE TO GET BRIEFLY INTO THE
UPPER 80S TO AROUND 90 DEGREES. SHOWERS AND STORMS WERE BEGINNING
TO FILL IN ACROSS THE EAST COAST METRO AREAS...AND NUMEROUS TO
WIDESPREAD SHOWERS AND ISOLATED/SCATTERED STORMS WILL CONTINUE
ACROSS SOUTH FLORIDA THROUGH THE AFTERNOON HOURS. THE MAIN THREAT
THIS AFTERNOON WILL BE LOCALLY HEAVY RAINFALL AND ISOLATED STREET
FLOODING FOR THE EAST COAST METROS. GUSTY WINDS UP TO 50 MPH ARE
ALSO POSSIBLE.
TONIGHT...SHOWERS AND STORMS WILL DIMINISH SLOWLY THIS EVENING
WITH LOSS OF DAYTIME HEATING...BUT REDEVELOPMENT IS POSSIBLE
OVERNIGHT FOR THE GULF WATERS THROUGH THE NAPLES REGION. THE AREA
OF LOW PRESSURE OFF THE EAST COAST OF NORTH FLORIDA WILL MOVE
NORTHEAST OVERNIGHT...BUT THE FRONTAL BOUNDARY ACROSS CENTRAL
FLORIDA WILL REMAIN STATIONARY.
SUNDAY AND MONDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH
FLORIDA TO THE SOUTH OF THE BOUNDARY ACROSS CENTRAL FLORIDA...WITH
PWATS AROUND 2 INCHES. WEAK UPPER TROUGHING WILL ALSO CONTINUE
ACROSS THE REGION. A FEW MID LEVEL IMPULSES SLIGHTLY DETACHED
FROM THE PARENT 500MB SHORTWAVE WELL TO THE NORTH ARE EXPECTED TO
SLIDE TO THE NORTHEAST ACROSS THE NORTHERN INTERIOR. THIS SHOULD
ENHANCE THUNDERSTORM DEVELOPMENT OVER THE AREA FOR THROUGH THE
BEGINNING OF NEXT WEEK. NUMEROUS SHOWERS AND STORMS ARE EXPECTED
EACH AFTERNOON.
A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST
THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES
FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE
DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS
DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE
REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER
ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO
SEVERE THUNDERSTORM POTENTIAL LIMITED.
&&
.AVIATION...
SCATTERED SHOWERS AND STORMS ASSOCIATED WITH A FRONTAL BOUNDARY
AND UPPER TROUGH WILL CONTINUE TO DEVELOP AND INCREASE IN
COVERAGE ACROSS THE AREA THROUGH THE AFTERNOON HOURS. WSW FLOW
WILL FOCUS THE HEAVIEST ACTIVITY TOWARD THE EAST COAST SITES
THROUGH THIS TIME TODAY. THE FLOW SHOULD PROVE TO BE TOO STRONG
FOR THE EAST COAST SEA BREEZE TO SET UP...WHICH IS REFLECTED WELL IN
THE LATEST HRRR RUN THAT INDICATES THE ACTIVITY PUSHING THROUGH
AND OFF THE COAST THROUGH THE EARLY EVENING PERIOD. VFR CONDITIONS
SHOULD RETURN THROUGH THE LATE EVENING AND OVERNIGHT HOURS WITH
LIGHT WESTERLY FLOW CONTINUING. 85/AG
&&
.MARINE...
GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD
PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO
THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP
THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS
ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET
OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 88 75 86 / 40 50 20 60
FORT LAUDERDALE 75 88 78 87 / 40 60 20 60
MIAMI 74 88 77 87 / 40 60 20 60
NAPLES 75 87 75 86 / 50 50 20 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...84/AK
LONG TERM....84/AK
AVIATION...85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
211 PM EDT SAT SEP 20 2014
.AVIATION...
SCATTERED SHOWERS AND STORMS ASSOCIATED WITH A FRONTAL BOUNDARY
AND UPPER TROUGH WILL CONTINUE TO DEVELOP AND INCREASE IN
COVERAGE ACROSS THE AREA THROUGH THE AFTERNOON HOURS. WSW FLOW
WILL FOCUS THE HEAVIEST ACTIVITY TOWARD THE EAST COAST SITES
THROUGH THIS TIME TODAY. THE FLOW SHOULD PROVE TO BE TOO STRONG
FOR THE EAST COAST SEA BREEZE TO SET UP...WHICH IS REFLECTED WELL IN
THE LATEST HRRR RUN THAT INDICATES THE ACTIVITY PUSHING THROUGH
AND OFF THE COAST THROUGH THE EARLY EVENING PERIOD. VFR CONDITIONS
SHOULD RETURN THROUGH THE LATE EVENING AND OVERNIGHT HOURS WITH
LIGHT WESTERLY FLOW CONTINUING. 85/AG
&&
.PREV DISCUSSION... /ISSUED 1015 AM EDT SAT SEP 20 2014/
UPDATE...
WET CONDITIONS EXPECTED AGAIN TODAY ACROSS SOUTH FLORIDA. LIGHT
SHOWERS WERE MOVING ACROSS THE GULF AND THE LAKE REGION THIS
MORNING. PWATS ON THE 12Z SOUNDING WERE JUST ABOVE 2 INCHES. AN
AREA OF LOW PRESSURE OFF THE EAST COAST OF CENTRAL FLORIDA WILL
DEEPEN AS IT MOVES NORTHEAST TODAY...WITH DEEP TRAILING MOISTURE
REMAINING ACROSS SOUTH FLORIDA. LIFT IS EXPECTED TO INCREASE
ACROSS THE LAKE REGION THROUGH THE DAY AS A SHORTWAVE ROTATES
AROUND THE BASE OF THE UPPER LOW LOCATED ACROSS THE
GEORGIA/FLORIDA BORDER. THE MAJOR LIMITING FACTOR THIS AFTERNOON
WILL BE CLOUD COVER...ESPECIALLY ACROSS THE LAKE REGION.
HOWEVER...WITH THE SYNOPTIC FEATURE ENHANCING LIFT...EXPECT
WIDESPREAD SHOWERS AND A FEW STORMS ACROSS THE NAPLES AREA AND
LAKE REGION. THE FIRST VISIBLE IMAGES THIS MORNING SHOW BREAKS
IN THE CLOUDS ACROSS THE SOUTHERN PORTION OF THE REGION...AND THE
DIFFERENTIAL HEATING MAY ALLOW FOR SHOWER AND STORM DEVELOPMENT
ACROSS THE EAST AND SOUTHEAST COAST IN THE AFTERNOON. THE HRRR AND
LOCAL WRF MODELS ARE HINTING AT THIS POSSIBILITY. SO KEPT THE
LIKELY POPS IN FOR THE REST OF THE REGION AS WELL. TEMPERATURES
WILL BE BELOW NORMAL ACROSS THE REGION DUE TO THE CLOUD COVER AND
RAINFALL.
PREV DISCUSSION... /ISSUED 855 AM EDT SAT SEP 20 2014/
AVIATION...
DESPITE THE EXTENSIVE MORNING CLOUD COVERAGE...THE LATEST VISIBLE
SATELLITE IMAGERY HAS ALREADY BEGUN TO INDICATE SOME OF THIS
COVERAGE THINNING OR BREAKING UP. IF THIS TREND
CONTINUES...DAYTIME HEATING COMBINED WITH AN UPPER TROUGH AND WEAK
FRONTAL BOUNDARY WILL SUPPORT SHRAS/TSTMS ONCE AGAIN THIS
AFTERNOON...POSSIBLY LATER DUE TO THE CURRENT CLOUD COVERAGE. WITH
THE WSW LOW-LEVEL FLOW IN PLACE...ANY SHRA/TSTM DEVELOP SHOULD
FOCUS TOWARD THE EAST COAST TODAY. 85/
PREV DISCUSSION... /ISSUED 418 AM EDT SAT SEP 20 2014/
DISCUSSION...
A WET PATTERN TO CONTINUE THROUGH THE WEEKEND AND MUCH OF NEXT
WEEK ACROSS SOUTH FLORIDA.
SHOWERS ASSOCIATED WITH A WEAK SURFACE TROUGH CONTINUE TO DIMINISH
WHILE PULLING TO THE NORTHEAST AND AWAY FROM SOUTH FLORIDA THIS
MORNING. HOWEVER...MOSTLY CLOUDY SKIES SHOULD REMAIN ACROSS THE
AREA THROUGH MUCH OF THE DAY AS A RESULT. CUTOFF H5 LOW AND
ASSOCIATED SURFACE LOW PRESSURE ACROSS NORTHERN FLORIDA ARE
EXPECTED TO SLOWLY PUSH TO THE NORTHEAST THROUGH THE DAY.
CONCURRENTLY...DEEP MOISTURE WILL CONTINUE TO SURGE INTO THE AREA
WITH MID LEVEL SOUTHWEST FLOW. THIS WILL PRODUCE PWAT VALUES OF
AROUND 2 INCHES ACROSS THE AREA RESULTING IN ANOTHER DAY OF
SHOWERS AND A FEW THUNDERSTORMS.
THE BEST COVERAGE OF SHOWERS AND STORMS LOOKS TO BE ACROSS THE
LAKE OKEECHOBEE AND PALM BEACH COUNTY AREAS WITH CLOSER PROXIMITY
TO THE H5 SHORTWAVE THUS ENHANCING LIFT. CLOUD COVER THROUGH THE
MORNING SHOULD GREATLY LIMIT STRONG THUNDERSTORM POTENTIAL THROUGH
THE AFTERNOON. VIRTUALLY ALL CONVECTIVE PARAMETERS DECREASE
THROUGH THE DAY AS A RESULT. COVERAGE OF SHOWERS AND STORMS SHOULD
DECREASE AGAIN AFTER DARK WITH LIMITED ACTIVITY LINGERING MAINLY
ACROSS THE AREA WATERS.
DEEP SOUTHWEST FLOW ALOFT SHOULD CONTINUE SUNDAY INTO MONDAY
KEEPING A DEEP MOISTURE AXIS ACROSS CENTRAL AND SOUTHERN FLORIDA.
THIS WILL KEEP A RATHER WET PATTERN THROUGH THE END OF THE WEEKEND
AND INTO THE START OF NEXT WEEK ACROSS THE AREA. A FEW MID LEVEL
IMPULSES SLIGHTLY DETACHED FROM THE PARENT H5 SHORTWAVE WELL TO
THE NORTH ARE EXPECTED TO SLIDE TO THE NORTHEAST ACROSS THE
NORTHERN INTERIOR. THIS SHOULD ENHANCE THUNDERSTORM DEVELOPMENT
SLIGHTLY OVER THE AREA FOR THE BEGINNING OF NEXT WEEK.
A MORE EASTERLY FLOW PATTERN RETURNS TUESDAY AND SHOULD PERSIST
THROUGH THE REMAINDER OF THE WEEK AS MID LEVEL RIDGING BECOMES
FIRMLY ENTRENCHED ACROSS THE WESTERN ATLANTIC. CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL PREVAIL EACH DAY WITH MODELS DEPICTING THE
DEEP MOISTURE AXIS REMAINING ACROSS SOUTH FLORIDA. MODEL SOUNDINGS
DEPICT PWAT VALUES RANGING BETWEEN 1.75-2.00 INCHES THROUGH THE
REMAINDER OF THE WEEK. THE DEEP MOISTURE AND RESULTANT CLOUD COVER
ALONG WITH AN OVERALL LACK OF DYNAMICS SHOULD KEEP THE STRONG TO
SEVERE THUNDERSTORM POTENTIAL LIMITED.
AVIATION...
A WEAK TROUGH OF LOW PRESSURE OVER FLORIDA WILL DEVELOP INTO A
LOW PRESSURE SYSTEM LATER TODAY. THIS LOW WILL KEEP SHOWERS AND
SOME THUNDERSTORMS OVER SOUTH FLORIDA THROUGH THE DAY. BY THIS
EVENING, THE LOW WILL BE EXITING THE AREA AND TAKE MUCH OF THE
PRECIPITATION ALONG WITH IT. FOR TODAY, EXPECTING MOSTLY RAIN
SHOWERS IN THE MORNING AND INTO THE AFTERNOON. IN THE AFTERNOON,
THE CHANCES OF THUNDERSTORMS WILL INCREASE. HAVE PLACED THE PROB30
GROUPS LATER IN THE DAY TO REFLECT THIS FOR THE EASTERN TAF SITES.
OVERALL, MAINLY VFR/MVFR CONDITIONS ACROSS SOUTH FLORIDA, WITH
BRIEF IFR POSSIBLE UNDER HEAVY SHOWERS AND/OR THUNDERSTORMS.
MARINE...
GENERAL SOUTHWESTERLY WINDS AT AROUND 10 KNOTS OR LESS SHOULD
PREVAIL THROUGH THE WEEKEND AS AN AREA OF LOW PRESSURE DEPARTS TO
THE NORTHEAST. A MORE EASTERLY FLOW REGIME WILL THEN SET UP
THROUGH THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE RETURNS
ACROSS THE WESTERN ATLANTIC. SEAS SHOULD REMAIN AT AROUND 3 FEET
OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 87 74 86 / 20 60 20 60
FORT LAUDERDALE 76 88 77 87 / 20 60 20 50
MIAMI 76 88 76 87 / 20 60 20 50
NAPLES 75 85 75 86 / 20 50 30 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....10/CD
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS JACKSON KY
231 PM EDT SAT SEP 20 2014
.UPDATE...
ISSUED AT 231 PM EDT SAT SEP 20 2014
BASED ON SATELLITE TRENDS...IT LOOKS LIKE THE THREAT OF SHOWERS HAS
ENDED AS THE BETTER CU FIELD IS WELL OUT TO OUR WEST. THUS...PLAN TO
GO DRY FOR THE REMAINDER OF THE DAY. NO OTHER CHANGES MADE AT THIS
TIME.
UPDATE ISSUED AT 1019 AM EDT SAT SEP 20 2014
BASED ON THE EXPANSION OF THE MID LEVEL AC HAVE OPTED TO GO AHEAD AND
EXPAND THE ISOLATED SHOWERS TO MOST OF EASTERN KENTUCKY. THE MID
LEVEL AC HAS A FEW VERTICAL TOWERS ALREADY SEEN FROM THE OFFICE. WITH
SOME WEAK INSTABILITY COMBINED WITH THE MID LEVEL INSTABILITY...WE
SHOULD SEE A FEW SHOWERS POP UP THIS AFTERNOON. EVERYTHING SHOULD
REMAIN FAIRLY ISOLATED AND THUNDER DOES NOT LOOK LIKE A THREAT AS
INSTABILITY IS NOT STRONG ENOUGH TO SUPPORT IT. OTHERWISE...NO OTHER
CHANGES PLANNED AT THIS TIME.
UPDATE ISSUED AT 740 AM EDT SAT SEP 20 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS AND
SATELLITE TRENDS. THIS LED TO SOME MINOR ADJUSTMENTS TO HOURLY
TEMPS AND DEWPOINTS TO START THE PERIOD. ANY LINGERING VALLEY FOG
SHOULD BE LIFTING AND DISSIPATING SHORTLY...IF IT HAS NOT ALREADY
DONE SO. WX GRIDS WERE UPDATED ACCORDINGLY AND AN UPDATED ZFP AND HWO
WILL FOLLOW SHORTLY.
CONFIDENCE IN THE EVOLUTION AND PLACEMENT OF ANY SHOWERS
LATER TODAY REMAINS LOWER THAN AVERAGE. THE NAM HAS BEEN THE MOST
INSISTENT ON ISOLATED SHOWER CHANCES FOR TODAY WHILE THE RECENT HRRR
RUNS POINT TOWARD THE POTENTIAL FOR A STRAY SHOWER JUST ABOUT
ANYWHERE IN THE CWA THIS MORNING INTO THE AFTERNOON...BUT ALSO HAD
ACTIVITY EARLIER IN THE MODEL RUN...BETWEEN 8Z AND PRESENT WHICH DID
NOT MATERIALIZE. THE CURRENT FORECAST HAS THE SLIGHT CHANCES ACROSS
THE WEST OR NORTHWEST IN LINE WITH THE HIGHEST 3Z SREF POPS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 355 AM EDT SAT SEP 20 2014
EARLY THIS MORNING...AN UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED
OVER THE SOUTHERN ROCKIES TO SOUTHERN PLAINS REGION WITH RIDGING EAST
INTO THE LOWER OH VALLEY WAS IN PLACE. ACROSS THE SOUTHEASTERN US...
A BROAD UPPER LEVEL LOW WAS PRESENT. MEANWHILE A SERIES OF SHORTWAVES
WERE IN THE NORTHERN STREAM WITH A WEAK LEAD SHORTWAVE NEAR THE MID
MS VALLEY REGION WITH ANOTHER SHORTWAVE NEARING THE NORTHERN GREAT
LAKES EXTENDING FROM WESTERN ONTARIO INTO THE UPPER MIDWEST AND DOWN
INTO THE CENTRAL PLAINS REGION. FURTHER NORTHWEST ANOTHER SHORTWAVE
IS MOVING ACROSS THE CANADIAN PLAINS.
THROUGH THE SHORT TERM PERIOD...THE LEAD WEAK SHORTWAVE WILL WORK
ACROSS THE AREA THROUGH EARLY TO MID AFTERNOON AS HEIGHTS BEGIN TO
FALL IN THE OH VALLEY REGION WHILE THE UPPER LEVEL RIDGE BUILDING
NORTH ACROSS THE ROCKIES AND INTO THE INTERIOR NORTHWESTERN US.
DOWNSTREAM ACROSS THE GREAT LAKES AND EASTERN US...A TROUGH OF LOW
PRESSURE WILL BEGIN TO BE CARVED OUT BY THE TWO MAIN SHORTWAVES AND
SOUTHEASTERN CONUS TROUGH BEGINNING TO MERGE INTO IT. THE ASSOCIATED
SFC LOW WILL TRACK WELL NORTH OF KY...BUT THE TRAILING COLD FRONT
WILL WORK INTO THE LOWER OH VALLEY REGION TONIGHT AND THEN MOVE
ACROSS THE COMMONWEALTH THROUGH THE END OF THE PERIOD...WHEN IT
SHOULD BE CLOSE TO EXITING INTO VA.
SCATTERED TO BROKEN CLOUDS IN THE 4 TO 7KFT RANGE HAVE DEVELOPED
OVERNIGHT IN THE WARM SECTOR. OUTSIDE OF THESE CLOUDS VALLEY FOG IS
LIKELY STILL PRESENT AND MAY BE DENSE AT LEAST IN SOME SPOTS ALONG THE
RIVERS AND LARGER STREAMS AND LAKES. DEWPOINT DEPRESSIONS ARE LARGER
NEARER TO THE VA BORDER WHERE A DOWNSLOPE FLOW HAS BEEN PRESENT WITH
SPEEDS OF 10 MPH OR MORE ACROSS THE HIGH TERRAIN AND OBSERVATIONS
SUPPORT ANY FOG BEING MUCH MORE LOCALIZED THERE. THIS FOG SHOULD
GRADUALLY BEGIN TO LIFT THROUGH SUNRISE AND THEN DISSIPATE BY A
COUPLE OF HOURS AFTER SUNRISE. IN ADDITION...WHERE CLOUDS FORM THIS
FOG WILL TEND TO DISSIPATE AS WELL.
THE MODEL GUIDANCE BRINGS THE WEAK MID LEVEL DISTURBANCE TOWARD THE
AREA FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY AFTERNOON.
THE 0Z NAM AND SOME OF THE NEAR TERM GUIDANCE SUCH AS THE HRRR ALSO
DEVELOP SOME CONVECTION THIS MORNING THROUGH EARLY AFTERNOON MAINLY
ACROSS THE WESTERN HALF OF THE CWA. MOS GUIDANCE ACROSS THESE
LOCATIONS DOES NOT HAVE A SLIGHT CHANCE POPS AND MODEL CONSENSUS
BLENDS GENERALLY STAYED BELOW SLIGHT AS WELL. HOWEVER...WE OPTED TO
GO WITH SLIGHT CHANCE IN THESE WESTERN LOCATIONS FOR TODAY...WHICH
WAS IN BETTER AGREEMENT WITH SURROUNDING WFOS.
THE MAIN PRECIPITATION CHANCE DURING THE SHORT TERM PERIOD AND THE
ENTIRE FORECAST PERIOD FOR THAT MATTER WILL COME AS THE TROUGH
BEGINS TO TAKE SHAPE LATE TONIGHT INTO THE DAY ON SUNDAY AND THE COLD
FRONT ENTERS EASTERN KY. THIS COLD FRONT AND THE APPROACHING TROUGH
IS EXPECTED TO BRING A BAND OF SCATTERED OR BETTER COVERAGE OF
CONVECTION AS IT WILL BE MOVING ACROSS EASTERN KY DURING THE DAYTIME.
ISOLATED TO SCATTERED CONVECTION MAY REACH THE NORTHERN PART OF THE
CWA TOWARD DAWN...BUT THE BEST CHANCE FOR CONVECTION WILL BE CLOSER
TO THE COLD FRONT GENERALLY DURING THE AFTERNOON HOURS. THUNDERSTORMS
WILL BE CAPABLE OF BRIEF HEAVY RAIN AND POSSIBLY SOME GUSTY
WINDS...PENDING THE DEGREE OF INSTABILITY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 324 AM EDT SAT SEP 20 2014
A QUICK MOVING COLD FRONT WILL BE EXITING THE REGION AS OF 0Z MONDAY.
MODELS CONTINUE TO COME INTO A BETTER AGREEMENT FOR THE ENDING TIME
OF PRECIP ASSOCIATED WITH THE FRONT...WITH THE NW EXPECTED TO CLEAR
OUT BY 0Z...AND FINALLY THE SE JUST AFTER 6Z MONDAY. LATEST FORECAST
SOUNDINGS ARE STILL ONLY SUPPORTING MARGINAL INSTABILITY FOR THE
PRECIP ACCOMPANYING THIS FRONT...QUICKLY DISSIPATING AS WE LOSE
DAYTIME HEATING...AND ONCE THE FRONTAL BOUNDARY HAS PASSED. AS
SUCH...THUNDER WAS MENTIONED IN PREVIOUS FORECAST PAST 0Z...AND HAS
ALSO BEEN INCLUDED BY SURROUNDING OFFICES THROUGH THE FIRST PART OF
THE EVENING. DID NOT FEEL CONFIDENT ENOUGH TO YANK MENTION OF THUNDER
COMPLETELY AT 0Z...SO KEPT MENTION OF SLIGHT CHANCE THUNDER WITH
CHANCE POPS THROUGH 3Z...WHICH CONSEQUENTLY IS ABOUT THE SAME TIME
CHANCE POPS EXIT THE REGION ANYWAYS. THERE IS SOME CONCERN THAT THE
COMBINATION OF STRONG SUBSIDENCE BEHIND THE FRONT...IN ADDITION TO
THE LINGERING MOISTURE ACROSS THE REGION...WILL LEAD TO A WIDESPREAD
FOG EVENT BY LATE SUNDAY NIGHT...OR PERHAPS A LOW STRATUS EVENT. THE
EXTENT OF EITHER OF THESE IS STILL SOMEWHAT UNCERTAIN. DECIDED TO
INCREASE CLOUDS SLIGHTLY OVERNIGHT SUNDAY NIGHT/MONDAY MORNING...BUT
DID NOT MENTION FOG AT THIS TIME.
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 DURING
THE DAY MONDAY...BUT HIGH TEMPERATURES WILL STRUGGLE TO MAKE IT TO
THE 70 DEGREE MARK. AIRMASS MODIFICATION...NAMELY THE LESSENING OF
STRONG PRESSURE GRADIENT/NW FLOW AS THE UPPER LEVEL RIDGE TAKES FULL
CONTROL...WILL SLOWLY ALLOW TEMPS TO RISE THROUGHOUT THE REMAINDER
OF THE EXTENDED FORECAST PERIOD. HOWEVER WE LIKELY WON/T SEE TEMPS
HIT ABOVE THE 80 DEGREE MARK AGAIN UNTIL AT LEAST NEXT WEEKEND.
MEANWHILE...WITH SUCH STRONG SUBSIDENCE IN CONTROL...THERE WILL BE
LITTLE CONCERN FOR CLOUDS...LET ALONE PRECIP CHANCES. ALL IN ALL IT
LOOKS TO BE A GORGEOUS AUTUMN-LIKE WEEK AHEAD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 231 PM EDT SAT SEP 20 2014
VFR CONDITIONS WILL CONTINUE OVER THE NEXT 24 TO 36 HOURS. SOME
PATCHY VALLEY FOG WILL BE POSSIBLE AGAIN TONIGHT. A COLD FRONT WILL
DROP SOUTH INTO THE AREA TOMORROW MORNING WITH CLOUDS AND
PRECIPITATION CHANCES ON THE INCREASE. AT THIS TIME...IT APPEARS CIGS
SHOULD REMAIN AT OR ABOVE 3500 FEET.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
314 PM EDT SAT SEP 20 2014
.SHORT TERM...THIS AFTERNOON AND TONIGHT
SEVERAL OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION WELL TO THE
WEST ARE TRACKING ACROSS LOWER MICHIGAN. HOWEVER...18Z DTX SOUNDING
SHOWS A RATHER ROBUST CAP IN THE 875-850MB AREA...WHICH WILL LIKELY
TAKE QUITE SOME TIME TO TOTALLY ERODE. MODELS...INCLUDING PRIMARY
AND PARALLEL HRRR RUNS TODAY...SUGGEST CONVECTION WILL EVENTUALLY
FILL IN ALONG BOTH OUTFLOW BOUNDARY SINKING SOUTH/SOUTHEAST THROUGH
THE CWA AND ALSO ALONG VORTICITY SPOKE FURTHER WEST ASSOCIATED WITH
LEFTOVER WEAK MCV. GIVEN CAPPING...AND THE LACK OF SIGNIFICANT
INSTABILITY...EXPECT THIS ACTIVITY TO REMAIN RATHER DISORGANIZED AND
SUB-SEVERE FOR THE MOST PART.
WILL STILL WATCH FOR THE POTENTIAL OF A FEW SEVERE STORMS AS WIND
FIELDS ARE DECENT...INCREASING FROM 25-30 KNOTS H85-H7 TO 50 KNOTS
AT H5. WITH ADDITIONAL HEATING...TEMPERATURES AROUND 80F DETROIT
SOUTH...OVER THE SOUTHERN CWA AND A LACK OF NOTABLE DEEP LOW LEVEL
MOISTURE...INVERTED-V SOUNDINGS MAY ASSIST IN GUST POTENTIAL GIVEN
THE ABOVE ATMOSPHERIC WIND SPEEDS.
THIS INITIAL PUSH OF FORCING...AND WHATEVER CONVECTION COMES OF
IT...WILL SHIFT EAST/SOUTHEAST OF THE AREA LATE THIS AFTERNOON/EARLY
THIS EVENING. HOWEVER...HIGHER THETA-E AIR WILL CONTINUE TO SHIFT
OVER THE CWA...PARTICULARLY M 59 SOUTH...WITHIN SOUTHWEST FLOW IN
ADVANCE OF MAIN SHORTWAVE TROUGH AXIS. SO...ADDITIONAL SCATTERED
SHOWERS/EMBEDDED STORMS WILL BUILD THROUGH AREA INTO THIS EVENING.
ONCE THIS ACTIVITY EBBS LATE THIS EVENING...EXPECT RENEWED SHOWER
AND STORM DEVELOPMENT LATE TONIGHT AS MAIN UPPER LEVEL SHORTWAVE
DIGS FROM THE UPPER MISSISSIPPI VALLEY INTO THE CENTRAL GREAT LAKES.
WITH MILD...SOUTHWEST FLOW PERSISTING THROUGH THE NIGHT...MINIMUM
TEMPERATURES WILL BE RATHER MILD...HOLDING IN THE 60S IN MOST
LOCATIONS...ESPECIALLY AS FURTHER CLOUDS/PRECIPITATION PROVIDE
ADDITIONAL INSOLATION AND MINIMIZE RADIATIONAL COOLING FURTHER.
&&
.LONG TERM...
LATEST WATER VAPOR IMAGERY SHOWS A STRONG BUT PROGRESSIVE UPPER
LEVEL SYSTEM/CIRCULATION OVER SOUTHERN MANITOBA...WITH A STRONGER
EMBEDDED UPPER WAVE AT THE BASE OF THE TROUGH OVER NORTH DAKOTA. IT
IS THIS UPPER WAVE/COLD POOL (-18 TO -19 C) WHICH WILL ARRIVE OVER
SOUTHERN LOWER MICHIGAN SUNDAY MORNING. WITH SOME LEFTOVER LOW LEVEL
MOISTURE AND MORE THAN ADEQUATE MID LEVEL LAPSE RATE (6.5+ C/KM FROM
700-500 MB)...ADDITIONAL SHOWERS AND EMBEDDED THUNDERSTORMS APPEAR
LIKELY DURING SUNDAY. A SECONDARY UPPER WAVE/COLD POOL WILL FOLLOW
ON THE BACKSIDE THROUGH THE WESTERN GREAT LAKES AND INTO THE OHIO
VALLEY. DEEP NORTHERLY FLOW IN THIS SYSTEMS WAKE OVER THE CENTRAL
GREAT LAKES WILL ALLOW FOR SOLID COLD ADVECTION TO TAKE PLACE...AS
850 MB TEMPS LOWER INTO THE LOW SINGLE NUMBERS...WITH SLIGHTLY
NEGATIVE VALUES OVER LAKE HURON...PER 12Z EURO/NAM. AS SUCH...FULLY
ONBOARD WITH THE 12Z NAM 925 MB RH/LOW CLOUDS AS NORTHERLY FLOW
COMES OFF THE RELATIVELY WARM WATERS OF LAKE HURON SUNDAY NIGHT.
HAVE SUBSEQUENTLY RAMPED UP THE CLOUDS MONDAY MORNING...WHICH WILL
LIKELY TAKE MUCH OF THE DAY TO MIX OUT/ERODE...HOLDING MAXES CLOSE
TO 60 DEGREES. FAVORABLE RADIATING CONDITIONS MONDAY NIGHT EXPECTED
TO ALLOW MINS TO FALL INTO THE 40S.
STUBBORN HIGH PRESSURE AND RELENTLESS LOW RH VALUES THROUGH THE
COLUMN WILL REMAIN IN PLACE FOR THE ENTIRE EXTENDED PERIOD. FLOW
WILL CONTINUE TO BE WEAK UNDER AN OMEGA BLOCKING HIGH. TEMPERATURES
WILL TREND SLIGHTLY ABOVE NORMAL WITH NO THREAT OF PRECIPITATION.
&&
.MARINE...
WARMER AIRMASS AHEAD OF COLD FRONT...COUPLED WITH THE WEAKENING
PRESSURE GRADIENT AS THE FRONT APPROACHES IS TRANSLATING
TO WIND SPEEDS BELOW 25 KNOTS...AND WILL DROP THE SMALL CRAFT
ADVISORIES. HOWEVER...SHOWERS AND THUNDERSTORMS WILL LIKELY
DEVELOP...AND THUNDERSTORMS WILL BE STRONG TO POSSIBLY SEVERE INTO
TONIGHT. A SECONDARY UPPER WAVE AND COLD FRONT WILL LEAD TO
ADDITIONAL SHOWERS TOMORROW AND POSSIBLE THUNDERSTORMS. BRISK
NORTHERLY WINDS OF 20 TO 25 KNOTS WILL FOLLOW THIS FRONT...ALLOWING
LARGE WAVE TO BUILD OVER SOUTHERN LAKE HURON SUNDAY NIGHT INTO
MONDAY...WITH SMALL CRAFT ADVISORIES LIKELY NEED DURING THAT TIME
FRAME. HIGH PRESSURE WILL EXERT FAVORABLE INFLUENCE ON THE WATERS
DURING THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...ISSUED 1251 PM EDT SAT SEP 20 2014
//DISCUSSION...
FORCING ALONG LEAD OUTFLOW BOUNDARY/WEAK MCV CENTER SHOULD BRING SCT
CONVECTION TO LOWER MICHIGAN BY 17Z-19Z...WELL AHEAD OF THE SYNOPTIC
TROUGH AXIS WEST OVER WISCONSIN. THIS ACTIVITY WILL ORGANIZE TO SOME
DEGREE AS IT MOVES INTO TERMINALS...BUT GIVEN THE EARLIER ARRIVAL OF
ACTIVITY...INSTABILITY WILL REMAIN LIMITED AS SURFACE DEW POINTS
STRUGGLE TOWARDS 60F IN ADVANCE OF THIS INITIAL ACTIVITY.
AFTER THIS PUSH OF SHRAS/EMBEDDED THUNDER...HIGHER THETA-E AIR WILL
CONTINUE TO FUNNEL INTO AREA IN ADVANCE OF MAIN TROUGH...LEADING TO
A CONTINUATION OF RATHER DISORGANIZED CONVECTION INTO THE EVENING
GENERALLY SOUTH OF M 59. RENEWED ACTIVITY CAN THEN BE EXPECTED BY
LATE TONIGHT/SUNDAY MORNING AS MAIN UPPER SHORTWAVE DIGS INTO THE
AREA...DURING WHICH TIME CIGS WILL CONSISTENTLY DROP TO MVFR OR
PERHAPS IFR AT TIMES.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW BEYOND 22Z
THIS AFTERNOON.
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET AFTER 22Z...WITH
PROGRESSIVELY HIGHER CONFIDENCE FROM TONIGHT INTO SUNDAY MORNING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...UNTIL 8 PM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DG
LONG TERM....SF/MM
MARINE.......SF
AVIATION.....DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1215 PM MDT SAT SEP 20 2014
.UPDATE...
QUICK UPDATE TO RAISE MAX TEMPS FOR THIS AFTERNOON IN THE NORTHEAST.
&&
.AVIATION...
18Z TAF CYCLE
STILL SOME IFR CIGS PERSISTING ROUGHLY SE OF A LINE FROM KSRR TO
KTCC. KROW WILL BE IMPACTED THE MOST...THOUGH SHOULD SEE IT WAFFLE
BTW SCT AND BKN OVER THE NEXT FEW HOURS. EASTERLY WINDS WILL
INCREASE AS THE AFTN PROGRESSES...ESPECIALLY BELOW GAPS AT KABQ
AND KSAF. MAY NEED TO ISSUE AN AWW LATER FOR KABQ FOR WIND GUSTS
GREATER THAN 35KT. OTHERWISE...SOME SPOTTY SHRA AND TSRA ACROSS
THE NORTH AND WEST THIS AFTN/EVE. CONFIDENCE IS ONLY HIGH ENOUGH
TO INCLUDE A VC MENTION AT THIS TIME AT KFMN...KGUP AND KSAF.
SHOULD SEE ANOTHER ROUND OF LIFR/IFR CIGS AND PERHAPS VSBYS AFT
06Z TONIGHT ALONG AND EAST OF THE CENTRAL MT CHAIN. MAY ALSO SEE
A FEW SHOWERS DEVELOP AROUND KROW NEAR SUNRISE SUNDAY.
34
&&
.PREV DISCUSSION...348 AM MDT SAT SEP 20 2014...
.SYNOPSIS...
VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO
WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER
MOISTURE WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER
AND THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF
THE EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A
DISTURBANCE ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW
MOISTURE FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD
EASTWARD INTO NORTHWEST NEW MEXICO MONDAY AND MOST AREAS TUESDAY.
MEANWHILE... TEMPERATURES WILL REMAIN GENERALLY ABOVE NORMAL
ACROSS THE WEST AND BELOW NORMAL ACROSS THE EAST. BY THE MIDDLE OF
NEXT WEEK...A DRYING TREND WILL TAKE A STRONGER HOLD ON THE
AREA...AND TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL
EXCEPT FOR THE SOUTHEAST PLAINS WHERE COOLER THAN AVERAGE
TEMPERATURE WILL LIKELY LINGER.
&&
.DISCUSSION...
EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE
CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO
DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST
SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK.
VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS
WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS
EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO
GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS
POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER
WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE
EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS
CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY.
AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX
TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS
ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC
MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED.
OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND
UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING
HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE
NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH
TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY
AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE
INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN
SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY
WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE
ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE
EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN
EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY
SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE-
SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO
THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM
MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY
LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR
WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES.
STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS
DEVELOP SUNDAY PM NW ZONES.
CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH
PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM
NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD
FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT
ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE
DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH
INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY
ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR
REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE
WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL
PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE
POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL
EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ
&&
.FIRE WEATHER...
UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT
DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL
SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE
EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM
TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION
EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING
RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN
ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED
ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC
MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO
MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP
ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL
MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE.
AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS
EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR
NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL
WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION
RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40
CORRIDOR.
MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES
IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL
WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO
CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY
ALONG AND NORTH OF I40.
A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA
STARTING TUE INTO AT LEAST THU...THOUGH 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, THOUGH NOT
DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO
APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL
DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS
DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS
POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF
STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN
CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1148 AM MDT SAT SEP 20 2014
.AVIATION...
18Z TAF CYCLE
STILL SOME IFR CIGS PERSISTING ROUGHLY SE OF A LINE FROM KSRR TO
KTCC. KROW WILL BE IMPACTED THE MOST...THOUGH SHOULD SEE IT WAFFLE
BTW SCT AND BKN OVER THE NEXT FEW HOURS. EASTERLY WINDS WILL
INCREASE AS THE AFTN PROGRESSES...ESPECIALLY BELOW GAPS AT KABQ
AND KSAF. MAY NEED TO ISSUE AN AWW LATER FOR KABQ FOR WIND GUSTS
GREATER THAN 35KT. OTHERWISE...SOME SPOTTY SHRA AND TSRA ACROSS
THE NORTH AND WEST THIS AFTN/EVE. CONFIDENCE IS ONLY HIGH ENOUGH
TO INCLUDE A VC MENTION AT THIS TIME AT KFMN...KGUP AND KSAF.
SHOULD SEE ANOTHER ROUND OF LIFR/IFR CIGS AND PERHAPS VSBYS AFT
06Z TONIGHT ALONG AND EAST OF THE CENTRAL MT CHAIN. MAY ALSO SEE
A FEW SHOWERS DEVELOP AROUND KROW NEAR SUNRISE SUNDAY.
34
&&
.PREV DISCUSSION...348 AM MDT SAT SEP 20 2014...
.SYNOPSIS...
VERY MOIST AIR MASS TO REMAIN IN PLACE ACROSS SOUTHEAST NEW MEXICO
WHERE SHOWERS AND A FEW THUNDERSTORMS ARE MOST FAVORED. DEEPER
MOISTURE WILL EXPAND WESTWARD LATE TODAY AND TONIGHT...WITH SHOWER
AND THUNDERSTORM ACTIVITY EXPECTED TO INCREASE AGAIN FOR PARTS OF
THE EASTERN PLAINS. AN OVERALL UPTICK IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED FOR SUNDAY AND SUNDAY EVENING AS A
DISTURBANCE ALOFT PASSES JUST NORTH OF THE STATE AND HELPS TO DRAW
MOISTURE FARTHER NORTH AND WEST. DRIER AIR WILL THEN SPREAD
EASTWARD INTO NORTHWEST NEW MEXICO MONDAY AND MOST AREAS TUESDAY.
MEANWHILE... TEMPERATURES WILL REMAIN GENERALLY ABOVE NORMAL
ACROSS THE WEST AND BELOW NORMAL ACROSS THE EAST. BY THE MIDDLE OF
NEXT WEEK...A DRYING TREND WILL TAKE A STRONGER HOLD ON THE
AREA...AND TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL
EXCEPT FOR THE SOUTHEAST PLAINS WHERE COOLER THAN AVERAGE
TEMPERATURE WILL LIKELY LINGER.
&&
.DISCUSSION...
EXTENSIVE LOW CLOUDS AND AT LEAST PATCHY DENSE FOG EAST OF THE
CENTRAL MOUNTAIN CHAIN EARLY THIS MORNING. EXPECT FOG TO
DEVELOP/EXPAND AND HAVE GREATEST IMPACT ALONG THE IMMEDIATE EAST
SLOPES AND ALONG THE WESTERN FRINGES OF PERSISTENT STRATUS DECK.
VERY MOIST AIR MASS REMAINS IN PLACE ACROSS THE SOUTHEAST PLAINS
WHERE SURFACE DEW POINT TEMPS SOLIDLY IN THE MID/UPPER 60S. THUS
EVEN WEAK UPSLOPE/LOW LEVEL CONVERGENCE IN THIS ENVIRON ENOUGH TO
GENERATE ISOLATED ACTIVITY THIS MORNING...AND ALL INDICATIONS
POINT TOWARD A GRADUAL STRENGTHENING OF THE E-SE BOUNDARY LAYER
WINDS ACROSS THE PLAINS AS THE DAY PROGRESSES AND MORESO INTO THE
EVENING HOURS. LATEST 13KM RAPID REFRESH /RAP/ AND HRRR MODEL RUNS
CONTINUE TO SUPPORT ISO-SCT COVERAGE FOR THE EC/SE ZONES TODAY.
AND GOOD AGREEMENT BETWEEN GFS/NAM SUPPORTING PREVIOUS POP/WX
TRENDS INCREASING POP FOR SE 1/4 TONIGHT WITH A PREFERRED AXIS
ALONG/WEST OF THE PECOS RIVER VALLEY TO EAST SLOPES OF THE SC
MOUNTAINS WHERE UPSLOPE EFFECTS WILL BE MAXIMIZED.
OUTSIDE THE SC MTNS AND EC/SE PLAINS...A PREDOMINATELY DRY AND
UNSEASONABLY WARM FORECAST TODAY BENEATH GRADUALLY STRENGTHENING
HIGH PRESSURE ALOFT THAT SHOULD CENTER NEAR OR JUST NORTH OF THE
NM/CO LINE TODAY BEFORE DEFLATING AND SHIFTING EAST AND SOUTH
TONIGHT- SUNDAY. THE SLIGHT AMPLIFICATION OF THE RIDGE ALOFT TODAY
AND THEN TRENDS INTO SUNDAY DUE TO A CLOSED LOW FORECAST TO MOVE
INTO CENTRAL CA LATE TODAY- TONIGHT THEN ACROSS THE GREAT BASIN
SUNDAY. THE ONE EXCEPTION TO THE PREDOMINATELY DRY FORECAST TODAY
WILL BE CATRON COUNTY/UPPER GILA REGION EXTENDING NORTH TOWARD THE
ZUNI MOUNTAINS NEAR THE NM/AZ LINE WHERE MID LEVEL MOISTURE
EXPECTED TO ADVECT NORTHWARD IN THE DEVELOPING S-SELY FLOW. AN
EXPANSION OF ISOLATED TO SCATTERED POPS EXPECTED AREAWIDE BY
SUNDAY...ESPECIALLY THE NORTH AND WEST...AS FORCING FOR LARGE-
SCALE LIFT AIDS CONVECTION SUNDAY PM. SURFACE PRESSURE FALLS TO
THE WEST OF THE STATE ASSOCIATED WITH THE CA LOW PRESSURE SYSTEM
MOST LIKELY RESPONSIBLE FOR THE STRENGTHENING E-SELY BOUNDARY
LAYER LATE TODAY AND TONIGHT. THIS WILL BRING HIGHER DEW POINT AIR
WESTWARD CONTRIBUTING TO THE OVERALL IMPROVING SHRA/TSRA CHANCES.
STORM MOTIONS WILL BE FAIRLY FAST BUT COULD SEE A FEW STRONG CELLS
DEVELOP SUNDAY PM NW ZONES.
CLOSED LOW TO OPEN UP AND PASS NORTH OF THE STATE MONDAY...WITH
PROGRESSIVELY DRIER AIR MASS INTO THE FOUR CORNERS. BEST POPS FROM
NE TO SW. TRANSITION TO NWLY FLOW ALOFT ON TUESDAY THAT WOULD
FAVOR THE NC/NE AREAS BUT WITH RESIDUAL MOISTURE CANNOT RULE OUT
ISOLATED- SCATTERED SHRA/TSRA ACROSS THE EAST AND SOUTH. DEFINITE
DRYING TREND NC/NW ZONES. FOR WED AND BEYOND...ANOTHER DEEP TROUGH
INDICATED INTO THE WEST COAST LATE NEXT WEEK BUT MUCH UNCERTAINTY
ON HOW QUICKLY IT WILL PROGRESS EAST. FARTHER DOWNSTREAM OVER OUR
REGION... POSITIVELY TILTED UPPER RIDGE MOST LIKELY TO DOMINATE
WITH A DEFORMATION AXIS OF SOME SORTS STRETCHING FROM THE CENTRAL
PLAINS STATES INTO FAR EASTERN NM BUT LOW CONFIDENCE. LOW GRADE
POP FORECAST IN PLACE FOR NOW WITH TEMPS GENERALLY BELOW NORMAL
EAST...AND NEAR TO SLIGHTLY ABOVE WEST. KJ
&&
.FIRE WEATHER...
UPPER LOW NEAR THE CENTRAL TO S CALIFORNIA COAST TO BE AN IMPORTANT
DRIVER IN LOWERING SFC PRESSURE OVER OR JUST W OF W NM WHICH WILL
SHIFT WINDS TO SOMEWHAT OF AN EASTERLY COMPONENT ACROSS MOST OF THE
EAST TWO THIRDS OR THREE QUARTERS OF NM BY LATE AM TO EARLY PM
TODAY. SOME DRYING THANKS TO A MODERATE MID LEVEL DRY INTRUSION
EXPECTED MAINLY ACROSS WESTERN AREAS. THE BEST CHANCE OF WETTING
RAIN TO BE FOUND ACROSS THE SE AND ALSO MUCH OF THE HIGHER TERRAIN
ELSEWHERE. GAP WIND GUSTS RANGING FROM 30 TO 40 MPH WILL BE EXPECTED
ALONG THE RIO GRANDE VALLEY TONIGHT INTO SUN MORNING. RESIDUAL SFC
MOISTURE AND MID TO UPPER LVL FLOW SHIFTING FROM E AND NE TODAY TO
MORE OF A SE TO S FLOW SUN TO SUN NIGHT PERIOD. THIS SHOULD HELP
ENHANCE WETTING RAIN POTENTIAL FOR SUN...FAVORING MOST THE CENTRAL
MTN CHAIN AND EAST AS WELL AS AREAS NEAR TO WEST OF THE DIVIDE.
AFTN TEMPS SHOULD BE WILL COOL ROUGHLY 5 TO 10 DEGREES MOST SPOTS
EXCEPT PERHAPS A BIT LESS SO ACROSS FAR E NM...BUT REMAIN NEAR
NORMAL ACROSS ROUGHLY THE NE HALF OF THE STATE. SOME BREEZY LEVEL
WIND AREAS EMBEDDED IN THE GENERALLY S TO SE FLOW SUN. VENTILATION
RATES LOOK TO BE FAIR TO GOOD FOR AREAS NORTH OF THE INTERSTATE 40
CORRIDOR.
MON TO AGAIN SOME WETTING RAIN CHANCES AND BELOW NORMAL TEMPERATURES
IN THE EAST AND TO SOME DEGREE SOUTH...LESS WETTING RAIN POTENTIAL
WITH NEAR NORMAL TEMPERATURES TO THE NW. VENTILATION NOT EXPECTED TO
CHANGE A LOT BETWEEN SUNDAY TO MONDAY WITH BETTER READINGS GENERALLY
ALONG AND NORTH OF I40.
A DRYING TREND STILL APPEARS TO BE IN THE CARDS OVER THE AREA
STARTING TUE INTO AT LEAST THU...THOUGH 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, THOUGH NOT
DRASTICALLY...TUE AND WED. THE NEXT UPPER TROUGH STILL LOOKS TO
APPROACH FOR LATE WEEK INTO THE FOLLOWING WEEKEND. SOME FCST MODEL
DIFFERENCES REMAIN IN STRENGTH AND TIMING. GFS MODEL STILL LOOKS
DEEPER AND SOMEWHAT FASTER WITH THE TROUGH THUS SOME WIND IMPACTS
POSSIBLE AHEAD OF IT. THIS SHOULD IMPROVE VENTILATION RATES. ECMWF
STILL IS A BIT SLOWER. MODEL DIFFERENCES STILL DRIVING DOWN
CONFIDENCE SOME FOR LATE WEEK INTO NEXT WEEK. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
630 PM EDT SAT SEP 20 2014
.SYNOPSIS...
HIGH PRESSURE BREAKS DOWN ACROSS THE AREA EARLY TONIGHT AS A LARGE
AREA OF LOW PRESSURE LIFTS NORTHEAST ALONG THE SOUTHERN US COAST
TONIGHT THROUGH THE DAY ON SUNDAY. A COLD FRONT WILL MOVE THROUGH
MONDAY. HIGH PRESSURE BEHIND THE FRONT WILL BUILD IN BEHIND THE
FRONT TO THE NORTH OF THE AREA AND REMAIN THERE THROUGH LATE WEEK.
&&
.NEAR TERM /REST OF THE NIGHT/...
AS OF 630 PM SAT...LARGE AREA OF MODERATE TO OCNL HEAVY RAIN
MOVING ONSHORE ACROSS OUTER BANKS/CARTERET COUNTY EARLY THIS
EVENING. THIS IN ASSOCIATION WITH ENHANCED MID LEVEL OMEGA/FGEN
OBSERVED IN RUC X-SECTIONS. HAVE INC POPS A BIT MORE TO ACCOUNT
FOR NEAR TERM TRENDS AND EXPECTED INC IN VORT ADVECTION ALONG THE
COAST THROUGH THE NIGHT. HAVE CORRESPONDINGLY INC QPF AMOUNTS
THROUGH THE NIGHT AS DUAL POL P-RATES JIVING WITH OBSERVED RATES
OF 1 TO OCNL 2 INCHES PER HOUR. BOUTS OF HEAVY RAIN WILL CONTINUE
TO ROTATE ONSHORE THROUGH THE NIGHT AS LOW AXIS MOVES NORTHWARD
JUST OFFSHORE CONTINUING STRONG THERMAL GRADIENT AND ACTS TO GENERATE
STRONG OMEGA/FGEN. LOCALIZED FLOODING WITH THE HEAVIER SHOWERS
CERTAINLY WILL BE A THREAT...AND HAVE INCLUDED HEAVY RAIN WORDING
IN FCST GRIDS.
PREVIOUS DISCUSSION...EXPECT THE BRIEF LULL IN SHOWER ACTIVITY THIS
AFTERNOON TO NOT LAST LONG AS A LARGE AREA OF SHOWERS ASSOCIATED
WITH THE LOW LIFTING NORTHEAST OFF THE SOUTHEASTERN US COAST MAKES
ITS WAY TOWARDS THE COAST. CARRIED CATEGORICAL 80 POPS ALONG THE
IMMEDIATE COAST FOR TONIGHT FROM THE VICINITY OF LOOKOUT THROUGH
CAPE HATTERAS...ASSOCIATED WITH THE LOW AND AN UPPER TROF ACROSS
THE SOUTHEAST. PRECIPITABLE WATER VALUES WILL BE ABNORMALLY HIGH
ACROSS THE COAST TONIGHT PERHAPS A BIT ABOVE 2.25 INCHES AS A
PLUME OF TROPICAL MOISTURE STREAMS UP THE COAST. THIS IS ABOUT TWO
STANDARD DEVIATIONS ABOVE NORMAL. EXPECT TO SEE PERIODS OF VERY
HEAVY RAINFALL AS SHOWERS MOVE ACROSS THE COAST TONIGHT. THIS
COULD RESULT IN SOME MINOR FLOODING OF LOW LYING AND POOR DRAINAGE
AREAS. THE GOOD NEWS IS THE HEAVIEST PRECIPITATION SHOULD REMAIN
ALONG COASTAL AREAS...NOT PENETRATING TOO FAR INLAND. WILL SEE
EXTENSIVE CLOUD COVER ACROSS THE AREA OVERNIGHT. FOLLOWED A BLEND
OF MOS GUIDANCE WITH LOWS IN THE MID 60S INLAND TO LOWER 70S ALONG
THE COAST.
&&
.SHORT TERM /SUNDAY/...
AS OF 330 PM SAT...THE COASTAL LOW AND ASSOCIATED MOISTURE WILL
BEGIN TO DEPART THE AREA ON SUNDAY WITH DECREASING POPS FROM WEST
TO EAST THROUGH THE DAY. EXPECT RAIN TO BE OFF THE OUTER BANKS BY
AROUND MID AFTERNOON. CLOUDS WILL DECREASE FROM WEST TO EAST AS
WELL WITH CLEARING BY THE AFTERNOON MOST PLACES. AGAIN FOLLOWED A
BLEND OF MOS GUIDANCE WITH HIGHS IN THE LOW TO MID 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 255 PM SATURDAY...COLD FRONT WILL APPROACH THE AREA SUNDAY
NIGHT AND SHOULD PUSH OFFSHORE SOMETIME DURING THE LATE MORNING
HOURS ON MONDAY. GFS/NAM12/ECMWF CONTINUE TO INDICATE A BROKEN
LINE OF SHOWERS AND PERHAPS A TSTM OR TWO WILL ACCOMPANY THE
FRONT. STRONG HIGH PRESSURE WILL THEN EXPAND SOUTH FROM THE GREAT
LAKES MONDAY NIGHT AND TUESDAY WITH VERY COMFORTABLE FALL LIKE
TEMPERATURES FOR MOST OF THE AREA...WITH MID/UPPER 50S INLAND AND
LOW/MID 60S COAST. GFS AND ECMWF DIVERGE FOR THE MID WEEK PERIOD
WITH THE ECMWF CUTTING OFF THE SOUTHERN PORTION OF DEEP MID-LEVEL
TROUGH OVER SOUTH CAROLINA TUESDAY AFTERNOON THROUGH WEDNESDAY
WHILE THE GFS KEEPS A BROAD TROUGH OVER THE EASTERN US. AS A
RESULT...THE ECMWF IS MUCH WETTER SHOWING PRECIPITATION EVEN ON
TUESDAY WHILE THE GFS IS DRY TUESDAY AND WEDNESDAY. HAVE TRENDED
THIS PORTION OF THE FORECAST TOWARD THE GFS WHICH HAS BEEN MORE
CONSISTENT...BUT CANNOT IGNORE THE ECMWF SOLUTION COMPLETELY WHICH
IS CLOSE TO WPC GUIDANCE...AND THUS HAVE A SMALL POP IN THE
FORECAST...MAINLY EASTERN SECTIONS WEDNESDAY. WITH INVERTED
SURFACE TROUGH MOVING TOWARD THE COAST ON THURSDAY...BETTER
AGREEMENT WITH AT LEAST A SMALL CHANCE OF RAIN ACROSS THE REGION.
WITH A VERY WEAK UPPER LEVEL FLOW AND CONTINUED FEED OF MOISTURE
FROM THE ATLANTIC ON A SOUTHEAST FLOW...WILL LIKEWISE HAVE SMALL
POPS OVER MAINLY THE EASTERN TWO-THIRDS OF THE CWA FRIDAY AND
SATURDAY. TEMPERATURES WILL REMAIN FAIRLY CONSISTENT WITH HIGHS
MID/UPPER 70S WITH A FEW LOWER 80S AND NIGHTTIME LOWS MAINLY IN
THE UPPER 50S TO MID 60S THROUGH THE PERIOD.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY/...
AS OF 630 PM SAT...LARGE AREA OF RAIN SHOWERS MOVING ONSHORE OF
THE NC COAST THIS EVENING. BULK OF WIDESPREAD HEAVY RAIN WILL
REMAIN EAST OF THE TERMINALS...THOUGH WILL SEE OCNL BOUTS OF
HEAVIER SHOWERS POSSIBLY AFFECT ESP THE KEWN AND KOAJ TAF SITES
WITH MORE SCT ACTIVITY INLAND. CIGS WILL DROP TO MVFR FROM EAST TO
WEST ACROSS EASTERN NC THIS EVENING. COULD EVEN SEE SOME IFR
CONDITIONS WITH BEST CONFIDENCE OF A FEW HOURS OF IFR CIGS AT KEWN
WHERE DEEPER LOW LEVEL MOISTURE WILL EXIST LATE TONIGHT.
CONDITIONS WILL IMPROVE RAPIDLY ON SUNDAY AS AREA OF LOW PRES
MOVES AWAY FROM THE COAST AND WINDS TURN WNW BRINGING IN MUCH
DRIER AIR.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...COULD SEE SOME TEMPORARY REDUCTIONS TO MVFR
WITH A FEW SHOWERS ALONG THE COLD FRONT DURING THE MORNING HOURS
ON MONDAY. WITH DRY HIGH PRESSURE BUILDING IN FROM THE
NORTH...TUESDAY SHOULD BE VFR. ANTICIPATE MOSTLY VFR ON WEDNESDAY
AS WELL...AS MODEL UNCERTAINTY EXISTS BETWEEN GFS/ECMWF ON EXTENT
OF MOISTURE/PRECIPITATION INTO THE AREA. A BETTER AGREEMENT
BETWEEN MODELS EXISTS THURSDAY WITH SCATTERED SHOWERS AND
OCCASIONAL MVFR CEILINGS AND VSBYS. A MORE MOIST BOUNDARY LAYER BY
WEDNESDAY AND THURSDAY WILL ALSO LEAD TO PATCHY FOG DURING THE
LATE NIGHT AND EARLY MORNING HOURS WITH MVFR AND PSBL IFR
CONDITIONS.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 330 PM SAT...CONTINUED ON STRONG SIDE OF MODEL GUIDANCE FOR
THE REMAINDER OF THE AFTERNOON AND TONIGHT BLENDING THE HIGH RES
NAM/ARW INTO THE FORECAST FOR WINDS. SCA CONDITIONS WILL PERSIST ALL
COASTAL WATERS THROUGH SUNDAY. SEAS REMAIN HIGH AND HAVE JUMPED
TO 7 TO 8 FEET ACROSS PORTIONS OF THE NORTHERN AND CENTRAL WATERS
WITH 6 FOOT SEAS TO THE SOUTH. USED NWPS GUIDANCE AND HAD TO
INCREASE SLIGHTLY FOR THE EARLY PERIOD TONIGHT TO ACCOUNT FOR
HIGHER SEAS IN THE COASTAL WATERS. WILL SEE TREACHEROUS BOATING
CONDITIONS ACROSS THE COASTAL WATERS THROUGH THE DAY ON SUNDAY AS
SEAS BUILD TO 8 TO 9 FEET ACROSS THE WATERS AS THE AREA OF LOW
PRESSURE LIFTS ACROSS THE AREA.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 305 PM SATURDAY...AN UNSETTLED EXTENDED PERIOD EXPECTED ON
THE COASTAL WATERS AND SOUNDS. BASED ON LATEST OUTPUT FROM LOCAL
SWAN/NWPS MODEL...HAVE OPTED TO EXTEND THE SMALL CRAFT ADVISORY
NORTH OF OCRACOKE INTO MONDAY MORNING FOR SEAS. AFTER A BRIEF LULL
MONDAY/MONDAY NIGHT...WINDS/SEAS BUILD AGAIN TUESDAY INTO THURSDAY
WITH LONG FETCH NORTHEAST FLOW AROUND STRONG 1035 MB HIGH OVER
SOUTHERN NEW ENGLAND AND WEAK INVERTED TROUGH OFFSHORE. LONGER
RANGE WAVEWATCH GUIDANCE INDICATES THAT ELEVATED SEAS AND SMALL
CRAFT ADVISORY CONDITIONS ARE LIKELY TO EXTEND INTO NEXT WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...RSB
NEAR TERM...RSB/TL
SHORT TERM...RSB
LONG TERM...CTC
AVIATION...RSB/CTC/TL
MARINE...RSB/CTC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
557 PM EDT SAT SEP 20 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL SHIFT THROUGH THE GREAT LAKES TONIGHT AND
SUNDAY WITH THE THREAT FOR SHOWERS AND THUNDERSTORMS. A MILD NIGHT
IS IN STORE AHEAD OF THE FRONT TONIGHT...WITH LOWS IN THE 60S.
COOLER AIR WILL DROP IN QUICKLY BEHIND THE FRONT SUNDAY AFTERNOON
AND NIGHT...LEADING TO SEVERAL NIGHTS WITH LOWS IN THE 40S...WITH
PERHAPS SOME UPPER 30S IN OUTLYING AREAS. MUCH OF THE WORK WEEK
WILL FEATURE STRONG HIGH PRESSURE...WHICH WILL BRING MILD
DAYS...COOL NIGHTS...AND LOW HUMIDITY. PLENTY OF SUN IS EXPECTED
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
UPDATE...SPED UP ARRIVAL OF RAIN CHANCES BY AN HOUR OR TWO BASED
ON TIME TRENDS FROM RADAR ON NOW WELL-DEVELOPED LINE OF CONVECTION
FROM NERN IND BACK TO WCNTL IND. MOST CONCENTRATED N-S PORTION OF
LINE WITH HISTORY OF WIND DAMAGE WILL PASS NORTH OF OUR AREA
THROUGH EARLY EVENING. REST OF LINE SEEMS TO BE STRUGGLING TO BE
SEVERE...AND WE/RE WATCHING PORTION OF THE LINE FROM LOGANSPORT
BACK TO IL BORDER AS THE PORTION THAT WILL AFFECT US. GUST FRONT
NOW KICKING SWRD FROM SEGMENT OF LINE FROM COLUMBIA CITY BACK TO
LOGANSPORT SO THIS PORTION OF LINE LIKELY TO WEAKEN. MESOA OVER
IND/OH SHOWS INSTBY DECREASING WITH EWRD EXTENT INTO ILN CWA AND WITH
SUNSET APPROACHING STILL THINK OVERALL SEVERE THREAT IS MARGINAL.
DID UPDATE HWO TO GIVE HEADS UP TO WCNTL OHIO/ECNTL IND COUNTIES
THAT A GUSTY/WEAKENING LINE OF STORMS IS LIKELY 00Z-02Z. REF
MCD#1741 THAT A NEW WATCH /IF ISSUED/ MAY GRAB A COUPLE OF OUR FAR
NWRN COUNTIES. ALSO PULLED RAIN CHANCES IN NRN KY AS CUMULUS/PVS
SHRA DOWN THERE HAVE LARGELY DISSIPATED.
PREVIOUS DISCUSSION -> SEVERAL FOCI FOR PRECIPITATION NOW THROUGH
SUNRISE ON SUNDAY MORNING. FIRST...IS IN A RELATIVELY NARROW AXIS
OF HIGHER THETA-E THAT RUNS NORTHEAST ALONG THE OHIO RIVER INTO
THE CVG AREA THIS AFTERNOON. BOUNDARY LAYER DWPTS HAVE WITHSTOOD
MIXING TO REMAIN IN THE MID 60S YIELDING SOME MARGINAL MLCAPE FROM
200-500 J/KG. CONFLUENT FLOW/VERY WEAK CONVERGENCE HAS LED TO THIS
EXTENSION OF BUOYANCY AND SOME ISOLD SHRA HAVE DEVELOPED IN THIS
AXIS AND WILL CONTINUE TO DO SO THROUGH ABT 7-8 PM TIED STRONGLY
TO THE BOUNDARY LAYER FLOW/INSTBY. HAVE PLACED A SMALL RAIN CHANCE
IN PARTS OF OUR NRN KY COUNTIES FOR THIS EVENING TO ACCOUNT FOR
THIS THREAT.
LARGER CONCERN IS STRONG COLD FRONT WHICH IS SHIFTING THROUGH
WI/IA/NRN IL ATTM ATTENDANT TO A COUPLE OF HEIGHT FALL
CENTERS...ONE IN WI THIS AFTN AND ANOTHER VERY COMPACT ONE IN ERN
ND. LOW LEVEL FORCING IS STRONG WITH THE FRONT AND ASSOCIATED PRE-
FRONTAL TROUGH...AND DEEP LAYER FLOW IS INCREASING AS THE THROUGH
AMPLIFIES WITH TIME TONIGHT.
CONVECTION HAS RECENTLY ERUPTED AS OF 19Z JUST SOUTH OF CHICAGO
AND SPC WATCH #504 ACCOMPANIES THIS INCREASE IN CONVECTION OFF TO
OUR NW. ACCORDING TO 20.12Z AWR-WRF...20.09Z SREF...AND MULTIPLE
WELL-AGREED UPON HRRR RUNS...A RATHER ROBUST LINE OF STORMS WILL
DEVELOP ALONG/AHEAD OF THE FRONT OVER THE NEXT FEW HOURS AND PUSH
EAST/NORTHEAST. ORIENTATION/MAGNITUDE /30+KTS BY TONIGHT/ OF 0-3KM
SHEAR VECTOR IS FAVORABLE FOR SOME DURATION/ORGANIZATION TO LINE
SEGMENTS WHICH CAN ORIENT IN MORE N-S FASHION OR SOME VARIATION OF
THAT. NOT SURPRISINGLY...HRRR RUNS HAVE DEMONSTRATED SPORADIC SWATHS
OF DAMAGING WIND GUSTS > 50KTS ACROSS NRN IND POTENTIALLY
INVOLVING NWRN/WCNTL OH LATER THIS EVE /AFTER 10 PM OR SO/. REALLY
LIKE THE 5% WIND CONTOUR INTO WCNTL OHIO BASED ON THE HRRR/ARW WRF
SOLUTIONS SHOWING A WEAKENING ORGANIZED LINE COMING INTO OUR AREA
AROUND 10 PM...PERHAPS WITH SOME 40-50 MPH WINDS. THIS FITS
CURRENT MESOA WHICH HAS MINIMUM OF INSTBY IN WRN OH DUE TO MIXED
DWPTS IN THE 50S...SO LINE SHOULD WEAKEN CONSIDERABLY AS IT
CROSSES INTO OHIO...DESPITE BRINGING A MODEST INCREASE IN MOISTURE
VIA ADVECTION.
STRUGGLED A LOT WITH RAIN CHANCES...FEEL CONFIDENT ENOUGH FOR
LIKELY RAIN CHANCES WITH DYING LINE INTO ABOUT THE NWRN 1/2 OF OUR
FORECAST AREA...BUT ALL CAMS/PARAMETRIZED DATA SHOWING ACTIVITY
BECOMING MORE SCT WITH TIME AS NIGHT WEARS ON. SO RAIN CHANCES
OVERNIGHT RANGE FROM A LOW CONFIDENCE 20% IN FAR SOUTH/EAST UP TO
A 70% CHANCE OR SO IN WCNTL OH. ALL WILL DEPEND HOW QUICKLY THE
INCOMING LINE WEAKENS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
FIRST HEIGHT FALL CENTER MENTIONED ABOVE PULLS EAST OF THE AREA
SUNDAY MORNING TAKING PRIMARY CONVERGENCE/PREFRONTAL TROUGH WITH
IT THROUGH THE MORNING. RESIDUAL SHOWERS/STORMS TO CROSS THE AREA
IN THE MORNING AND THEN SCT STORMS WILL BEGIN TO BUBBLE ALONG THIS
BOUNDARY LATE MORNING/EARLY AFTERNOON AND LIKELY IN OUR FAR
SOUTH/EAST OR JUST OUT OF OUR AREA. RATHER IMPRESSIVE/NARROW DRY
SLOT SHOULD WRAP IN LATE MORNING/EARLY AFTERNOON WITH SOME
SUNSHINE BEFORE STRONG CAA SETS IN DURING THE AFTERNOON WITH THE
PASSAGE OF SECONDARY FRONT. WITH SHALLOW INSTBY DEVELOPING...COULD
SEE SOME SCT SHRA DEVELOP WITH THIS FEATURE WHICH WAS ALREADY WELL
HANDLED BY PVS FORECASTER. THIS MOST LIKELY ACROSS OUR NORTH
CLOSER TO STRONG/COMPACT SHORTWAVE DIGGING ACROSS NRN OH. DON/T
EXPECT MUCH IF ANY THUNDER AFTER ABOUT 18Z...AS INSTBY BECOMES TOO
SHALLOW FOR CHARGE SEPARATION. WILL DEFINITELY A BE A CHANGEABLE
/AUTUMN-LIKE DAY DESPITE MAX TEMPS IN THE 70S. WINDS WILL BECOME
BREEZY/GUSTY IN THE AFTN AS THE COLD ADVECTION ARRIVES AND
CHANGEABLE SKY WITH THE DRY SLOT TO LOWER CLOUDS ALONG/BEHIND THE
SECONDARY SURFACE FRONT.
AS THIS ACTION ALL CLEARS THE CWA SUNDAY NIGHT AND STRONG HIGH
PRESSURE BUILDS IN...A VERY CHILLY NIGHT IN STORE WITH LOWS WELL
INTO THE 40S IN OUR INDIANA/WRN OHIO COUNTIES AS 925MB TEMPS DROP
TO +5C IN THIS AREA BY SUNRISE ON MONDAY. SHOULD SEE A SLOW DECREASE
IN LOW CLOUDS THROUGH THE NIGHT AND LESSENING WINDS AS
WELL...GIVEN THE DEGREE OF COLD AIR INBOUND...AM A LITTLE WORRIED
I AM CLEARING THE SKIES A LITTLE TOO QUICKLY AND STRATOCUMULUS MAY
BE MORE WIDESPREAD.
MONDAY BRINGS 1024MB SURFACE HIGH PRESSURE SPRAWLING INTO THE
GREAT LAKES AND CENTERED NEAR CHICAGO BY MONDAY EVENING. SHOULD BE
PLENTY OF SUNSHINE WITH DEWPTS IN THE 40S. CONTINUED WEAK CAA
SHOULD KEEP 925MB TEMPS IN THE +8 TO +10C RANGE WHICH PER CLIMO
STUDY SUGGESTS MAX TEMPS IN THE LOW TO MID 60S MOST
AREAS...DESPITE PLENTY OF SUN. MONDAY NIGHT WILL BE COLDEST OF THE
WEEK AND WOULD NOT BE SURPRISED TO SEE COLD PRONE/OUTLYING SITES
TOUCH THE MID TO UPPER 30S AGAIN LIKE DELAWARE/MARYSVILLE ETC DID
LAST WEEK. MAY EVEN BE A TOUCH COLDER THIS TIME AROUND. LOW TEMPS
THIS NIGHT MAY STILL BE A DEGREE OR TWO TOO WARM IN GOING
FORECAST...ESPECIALLY WITH SURFACE HIGH MOVING RIGHT OVERHEAD AT
12Z AND THE VERY DRY PROFILE /PWATS RUNNING 40% OF NORMAL/. AN
IDEAL RADIATIONAL COOLING SIGNAL BEING SEEN IN THE DATA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MID/UPPER LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE REGION
THROUGH THE END OF THE WEEK. THIS WILL RESULT IN DRY CONDITIONS AND
FAIRLY SEASONABLE TEMPERATURES THROUGH THE LONG TERM PERIOD. AS THE
AIRMASS SLOWLY MODIFIES...HIGH TEMPERATURES WILL GRADUALLY WARM EACH
DAY...FROM THE LOW TO MID 70S MID WEEK INTO THE UPPER 70S TO AROUND
80 DEGREES BY THE WEEKEND.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
MVFR CEILINGS PERSIST AT CVG AND LUK...OTHERWISE TAF SITES HAVE
VFR. COLD FRONT WILL BE MOVING IN LATE TONIGHT/EARLY SUNDAY. THIS
WILL BRING SCATTERED SHOWERS AND POSSIBLY MORE MVFR CEILINGS. KEPT
THUNDER OUT FOR NOW SINCE FRONT WILL BE ARRIVING AT A DIURNALLY
UNFAVORABLE TIME. WINDS WILL GUST AROUND 20 KNOTS THIS AFTERNOON
OUT OF THE SOUTHWEST. GUSTS OVER 20 KNOTS ARE EXPECTED SUNDAY
AS DIRECTION SHIFTS TO WEST ALONG THE FRONT. CVG SHOULD SEE
CONTINUED GUSTY CONDITIONS AS WINDS BECOME NORTHWEST SUNDAY
AFTERNOON BEHIND THE FRONT.
OUTLOOK...MVFR CEILINGS POSSIBLE SUNDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
352 PM EDT SAT SEP 20 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL SHIFT THROUGH THE GREAT LAKES TONIGHT AND
SUNDAY WITH THE THREAT FOR SHOWERS AND THUNDERSTORMS. A MILD NIGHT
IS IN STORE AHEAD OF THE FRONT TONIGHT...WITH LOWS IN THE 60S.
COOLER AIR WILL DROP IN QUICKLY BEHIND THE FRONT SUNDAY AFTERNOON
AND NIGHT...LEADING TO SEVERAL NIGHTS WITH LOWS IN THE 40S...WITH
PERHAPS SOME UPPER 30S IN OUTLYING AREAS. MUCH OF THE WORK WEEK
WILL FEATURE STRONG HIGH PRESSURE...WHICH WILL BRING MILD
DAYS...COOL NIGHTS...AND LOW HUMIDITY. PLENTY OF SUN IS EXPECTED
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERAL FOCI FOR PRECIPITATION NOW THROUGH SUNRISE ON SUNDAY
MORNING. FIRST...IS IN A RELATIVELY NARROW AXIS OF HIGHER THETA-E
THAT RUNS NORTHEAST ALONG THE OHIO RIVER INTO THE CVG AREA THIS
AFTERNOON. BOUNDARY LAYER DWPTS HAVE WITHSTOOD MIXING TO REMAIN IN
THE MID 60S YIELDING SOME MARGINAL MLCAPE FROM 200-500 J/KG.
CONFLUENT FLOW/VERY WEAK CONVERGENCE HAS LED TO THIS EXTENSION OF
BUOYANCY AND SOME ISOLD SHRA HAVE DEVELOPED IN THIS AXIS AND WILL
CONTINUE TO DO SO THROUGH ABT 7-8 PM TIED STRONGLY TO THE BOUNDARY
LAYER FLOW/INSTBY. HAVE PLACED A SMALL RAIN CHANCE IN PARTS OF OUR
NRN KY COUNTIES FOR THIS EVENING TO ACCOUNT FOR THIS THREAT.
LARGER CONCERN IS STRONG COLD FRONT WHICH IS SHIFTING THROUGH
WI/IA/NRN IL ATTM ATTENDANT TO A COUPLE OF HEIGHT FALL
CENTERS...ONE IN WI THIS AFTN AND ANOTHER VERY COMPACT ONE IN ERN
ND. LOW LEVEL FORCING IS STRONG WITH THE FRONT AND ASSOCIATED PRE-
FRONTAL TROUGH...AND DEEP LAYER FLOW IS INCREASING AS THE THROUGH
AMPLIFIES WITH TIME TONIGHT.
CONVECTION HAS RECENTLY ERUPTED AS OF 19Z JUST SOUTH OF CHICAGO
AND SPC WATCH #504 ACCOMPANIES THIS INCREASE IN CONVECTION OFF TO
OUR NW. ACCORDING TO 20.12Z AWR-WRF...20.09Z SREF...AND MULTIPLE
WELL-AGREED UPON HRRR RUNS...A RATHER ROBUST LINE OF STORMS WILL
DEVELOP ALONG/AHEAD OF THE FRONT OVER THE NEXT FEW HOURS AND PUSH
EAST/NORTHEAST. ORIENTATION/MAGNITUDE /30+KTS BY TONIGHT/ OF 0-3KM
SHEAR VECTOR IS FAVORABLE FOR SOME DURATION/ORGANIZATION TO LINE
SEGMENTS WHICH CAN ORIENT IN MORE N-S FASHION OR SOME VARIATION OF
THAT. NOT SURPRISINGLY...HRRR RUNS HAVE DEMONSTRATED SPORADIC SWATHS
OF DAMAGING WIND GUSTS > 50KTS ACROSS NRN IND POTENTIALLY
INVOLVING NWRN/WCNTL OH LATER THIS EVE /AFTER 10 PM OR SO/. REALLY
LIKE THE 5% WIND CONTOUR INTO WCNTL OHIO BASED ON THE HRRR/ARW WRF
SOLUTIONS SHOWING A WEAKENING ORGANIZED LINE COMING INTO OUR AREA
AROUND 10 PM...PERHAPS WITH SOME 40-50 MPH WINDS. THIS FITS
CURRENT MESOA WHICH HAS MINIMUM OF INSTBY IN WRN OH DUE TO MIXED
DWPTS IN THE 50S...SO LINE SHOULD WEAKEN CONSIDERABLY AS IT
CROSSES INTO OHIO...DESPITE BRINGING A MODEST INCREASE IN MOISTURE
VIA ADVECTION.
STRUGGLED A LOT WITH RAIN CHANCES...FEEL CONFIDENT ENOUGH FOR
LIKELY RAIN CHANCES WITH DYING LINE INTO ABOUT THE NWRN 1/2 OF OUR
FORECAST AREA...BUT ALL CAMS/PARAMETRIZED DATA SHOWING ACTIVITY
BECOMING MORE SCT WITH TIME AS NIGHT WEARS ON. SO RAIN CHANCES
OVERNIGHT RANGE FROM A LOW CONFIDENCE 20% IN FAR SOUTH/EAST UP TO
A 70% CHANCE OR SO IN WCNTL OH. ALL WILL DEPEND HOW QUICKLY THE
INCOMING LINE WEAKENS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
FIRST HEIGHT FALL CENTER MENTIONED ABOVE PULLS EAST OF THE AREA
SUNDAY MORNING TAKING PRIMARY CONVERGENCE/PREFRONTAL TROUGH WITH
IT THROUGH THE MORNING. RESIDUAL SHOWERS/STORMS TO CROSS THE AREA
IN THE MORNING AND THEN SCT STORMS WILL BEGIN TO BUBBLE ALONG THIS
BOUNDARY LATE MORNING/EARLY AFTERNOON AND LIKELY IN OUR FAR
SOUTH/EAST OR JUST OUT OF OUR AREA. RATHER IMPRESSIVE/NARROW DRY
SLOT SHOULD WRAP IN LATE MORNING/EARLY AFTERNOON WITH SOME
SUNSHINE BEFORE STRONG CAA SETS IN DURING THE AFTERNOON WITH THE
PASSAGE OF SECONDARY FRONT. WITH SHALLOW INSTBY DEVELOPING...COULD
SEE SOME SCT SHRA DEVELOP WITH THIS FEATURE WHICH WAS ALREADY WELL
HANDLED BY PVS FORECASTER. THIS MOST LIKELY ACROSS OUR NORTH
CLOSER TO STRONG/COMPACT SHORTWAVE DIGGING ACROSS NRN OH. DON/T
EXPECT MUCH IF ANY THUNDER AFTER ABOUT 18Z...AS INSTBY BECOMES TOO
SHALLOW FOR CHARGE SEPARATION. WILL DEFINITELY A BE A CHANGEABLE
/AUTUMN-LIKE DAY DESPITE MAX TEMPS IN THE 70S. WINDS WILL BECOME
BREEZY/GUSTY IN THE AFTN AS THE COLD ADVECTION ARRIVES AND
CHANGEABLE SKY WITH THE DRY SLOT TO LOWER CLOUDS ALONG/BEHIND THE
SECONDARY SURFACE FRONT.
AS THIS ACTION ALL CLEARS THE CWA SUNDAY NIGHT AND STRONG HIGH
PRESSURE BUILDS IN...A VERY CHILLY NIGHT IN STORE WITH LOWS WELL
INTO THE 40S IN OUR INDIANA/WRN OHIO COUNTIES AS 925MB TEMPS DROP
TO +5C IN THIS AREA BY SUNRISE ON MONDAY. SHOULD SEE A SLOW DECREASE
IN LOW CLOUDS THROUGH THE NIGHT AND LESSENING WINDS AS
WELL...GIVEN THE DEGREE OF COLD AIR INBOUND...AM A LITTLE WORRIED
I AM CLEARING THE SKIES A LITTLE TOO QUICKLY AND STRATOCUMULUS MAY
BE MORE WIDESPREAD.
MONDAY BRINGS 1024MB SURFACE HIGH PRESSURE SPRAWLING INTO THE
GREAT LAKES AND CENTERED NEAR CHICAGO BY MONDAY EVENING. SHOULD BE
PLENTY OF SUNSHINE WITH DEWPTS IN THE 40S. CONTINUED WEAK CAA
SHOULD KEEP 925MB TEMPS IN THE +8 TO +10C RANGE WHICH PER CLIMO
STUDY SUGGESTS MAX TEMPS IN THE LOW TO MID 60S MOST
AREAS...DESPITE PLENTY OF SUN. MONDAY NIGHT WILL BE COLDEST OF THE
WEEK AND WOULD NOT BE SURPRISED TO SEE COLD PRONE/OUTLYING SITES
TOUCH THE MID TO UPPER 30S AGAIN LIKE DELAWARE/MARYSVILLE ETC DID
LAST WEEK. MAY EVEN BE A TOUCH COLDER THIS TIME AROUND. LOW TEMPS
THIS NIGHT MAY STILL BE A DEGREE OR TWO TOO WARM IN GOING
FORECAST...ESPECIALLY WITH SURFACE HIGH MOVING RIGHT OVERHEAD AT
12Z AND THE VERY DRY PROFILE /PWATS RUNNING 40% OF NORMAL/. AN
IDEAL RADIATIONAL COOLING SIGNAL BEING SEEN IN THE DATA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MID/UPPER LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE REGION
THROUGH THE END OF THE WEEK. THIS WILL RESULT IN DRY CONDITIONS AND
FAIRLY SEASONABLE TEMPERATURES THROUGH THE LONG TERM PERIOD. AS THE
AIRMASS SLOWLY MODIFIES...HIGH TEMPERATURES WILL GRADUALLY WARM EACH
DAY...FROM THE LOW TO MID 70S MID WEEK INTO THE UPPER 70S TO AROUND
80 DEGREES BY THE WEEKEND.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MVFR CEILINGS PERSIST AT CVG AND LUK...OTHERWISE TAF SITES HAVE
VFR. COLD FRONT WILL BE MOVING IN LATE TONIGHT/EARLY SUNDAY. THIS
WILL BRING SCATTERED SHOWERS AND POSSIBLY MORE MVFR CEILINGS. KEPT
THUNDER OUT FOR NOW SINCE FRONT WILL BE ARRIVING AT A DIURNALLY
UNFAVORABLE TIME. WINDS WILL GUST AROUND 20 KNOTS THIS AFTERNOON
OUT OF THE SOUTHWEST. GUSTS OVER 20 KNOTS ARE EXPECTED SUNDAY
AS DIRECTION SHIFTS TO WEST ALONG THE FRONT. CVG SHOULD SEE
CONTINUED GUSTY CONDITIONS AS WINDS BECOME NORTHWEST SUNDAY
AFTERNOON BEHIND THE FRONT.
OUTLOOK...MVFR CEILINGS POSSIBLE SUNDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1145 AM CDT SAT SEP 20 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT SAT SEP 20 2014
MAIN CONCERNS ARE ON EXITING MORNING CONVECTION AND THE RETURN FOR
MORE CONVECTION TONIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED AN UPPER LOW JUST OFF THE CALIFORNIA COAST...RIDGING OVER THE
WESTERN THIRD OF THE U.S. INTO BRITISH COLUMBIA...AND TROUGHING OVER
CENTRAL CANADA INTO THE NORTHERN PLAINS/UPPER MIDWEST. A COUPLE OF
SHORTWAVES TRAVERSING THROUGH THIS TROUGH IN SOUTH DAKOTA AND MN...
COMBINED WITH A SURFACE TO 850MB COLD FRONT THAT STRETCHED FROM
DULUTH TO SIOUX CITY IA...HAVE AIDED IN MAINTAINING A BAND OF
SHOWERS AND THUNDERSTORMS. THIS BAND EXTENDS FROM WEST CENTRAL IA
THROUGH THE FORECAST AREA. MUCH OF THE ACTIVITY HAS BEEN ELEVATED IN
NATURE DUE TO CAPPING PRESENT OF BL PARCELS. PLENTY OF INSTABILITY
FOR THE CONVECTION WITH CAPE VALUES LIFTED FROM 1 KM BETWEEN 1000-
2000 J/KG. IN THE WAKE OF THE CONVECTION...THERE HAS BEEN A NARROW
AREA OF LOW STRATUS DEVELOPING...BEFORE CLOUDS CLEAR OUT OVER
CENTRAL MN. AIRMASS BEHIND THE COLD FRONT WAS NOT MUCH COLDER THAN
AHEAD...WITH 925MB TEMPS HOVERING BETWEEN 20-24C. HOWEVER...
PRECIPITABLE WATER DROPS SIGNIFICANTLY FROM 1.5-1.75 INCHES TO 1-
1.25 INCHES. UPSTREAM A MORE SIGNIFICANT COLD FRONT EXISTS OVER
NORTHERN NORTH DAKOTA AND NORTHWEST MN WHERE 925MB TEMPS DROP TO 12-
14C.
THE COLLECTION OF SHORTWAVES ACROSS SOUTH DAKOTA AND MN ARE PROGGED
TO CROSS THE FORECAST AREA THIS MORNING...PUSHING THE SURFACE-850MB
COLD FRONT THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z. ANTICIPATING
MUCH OF THE CURRENT CONVECTION AHEAD OF THESE FEATURES TO MARCH
SOUTHEASTWARD OUT OF THE FORECAST AREA BY 13Z PER HIGH RESOLUTION
MODEL CONSENSUS. STILL CARRIED SOME LOW PRECIPITATION CHANCES OVER
THE SOUTHEAST HALF IN THE WAKE OF THE CURRENT ACTIVITY IN THE EVENT
ADDITIONAL SHOWERS/STORMS FORM AS THE SHORTWAVES MOVE IN.
OTHERWISE...SUBSIDENCE AND DRYING OF PRECIPITABLE WATER SHOULD ALLOW
SKIES TO CLEAR AFTER A BRIEF PERIOD OF MORNING STRATUS. THE SUNSHINE
COMBINED WITH 925MB TEMPS OF 18-20C FOR MUCH OF TODAY SHOULD ALLOW
FOR HIGHS TO TOP OUT IN THE 70S IN MOST LOCATIONS...WITH SOME LOW
80S IN VALLEYS.
SHORTLY AFTER 00Z THIS EVENING...ANOTHER LINE OF SHOWERS AND
EMBEDDED THUNDERSTORMS LOOKS LIKELY TO MOVE ACROSS THE REGION...
ESPECIALLY ALONG AND NORTH OF I-90. THIS LINE OF CONVECTION WILL BE
FORCED BY A POTENT SHORTWAVE OVER CENTRAL ALBERTA DROPPING THROUGH
THE UPPER MIDWEST TROUGHING. THE SHORTWAVE SHOULD ALSO HAVE A NARROW
CORRIDOR OF MOISTURE TO WORK WITH AS PRECIPITABLE WATER JUMPS UP TO
1-1.3 INCHES. INSTABILITY WISE...ITS FAIRLY MEAGER WITH VALUES OF
100-500 J/KG...MOSTLY IN THE EVENING DUE TO LOSS OF DAYTIME HEATING
COOLING THE BOUNDARY LAYER. ANTICIPATING MORE THUNDERSTORM ACTIVITY
SHOULD OCCUR TODAY UPSTREAM OVER NORTH DAKOTA INTO CENTRAL MN WHERE
THE JUXTAPOSITION OF HIGHER DIURNALLY BASED INSTABILITY INTERSECTS
THE SHORTWAVE. SHEAR PROFILES WOULD CERTAINLY SUPPORT BOTH A
DAMAGING WIND AND LARGE HAIL THREAT WITH CONVECTION...HOWEVER...THE
MEAGER INSTABILITY BY THE TIME THE CONVECTION MOVES INTO THE
FORECAST AREA SHOULD HELP MITIGATE SEVERE POTENTIAL. MAY STILL SEE
SOME STRONGER WIND GUSTS...THOUGH. HAVE RAISED PRECIPITATION CHANCES
UP FOR THE EVENING HOURS GIVEN VERY GOOD MODEL CONSENSUS FOR THIS
CONVECTION. KEPT SOME PRECIPITATION CHANCES GOING OVERNIGHT TOO
ALONG AND NORTH OF I-94 WHERE A FRONTOGENESIS BAND LOOKS TO SETUP ON
THE NORTH SIDE OF THE SHORTWAVE. LOOK FOR COOLER TEMPERATURES
TONIGHT AS COLDER AIR RUSHES IN BEHIND THE LINE OF CONVECTION. IN
FACT...925MB TEMPS COOL AS MUCH AS 10C ON A BRISK 30-40 KT 925MB
NORTHWEST WIND.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM CDT SAT SEP 20 2014
MAIN CONCERNS ARE ON PRECIPITATION POTENTIAL FOR SUNDAY...FOLLOWED
BY TEMPERATURES AND VALLEY FOG POTENTIAL SUNDAY NIGHT AND BEYOND.
ANOTHER POTENT SHORTWAVE LOOKS TO FOLLOW QUICKLY ON THE HEELS OF THE
ONE MOVING THROUGH THE FORECAST AREA TONIGHT. THIS SHORTWAVE...
CURRENTLY IN NORTHERN SASKATCHEWAN...IS PROGGED TO DROP SOUTH
THROUGH THE FORECAST AREA SUNDAY MORNING. THIS SHORTWAVE WILL HELP
TO PULL THE FRONTOGENESIS BAND AND ASSOCIATED SURFACE COLD FRONT
SOUTHWARD THROUGH THE FORECAST AREA DURING THE MORNING HOURS.
APPEARS THE BULK OF THE RAIN/SHOWER ACTIVITY WITH THE BAND WILL BE
CONFINED TO WISCONSIN...BUT SOME MAY EVEN CREEP ACROSS THE MS RIVER
AS SUGGESTED BY THE 20.00Z ECMWF/CANADIAN. HAVE RAISED PRECIPITATION
CHANCES UPWARDS AND FURTHER INCREASES MAY BE NECESSARY. OVERALL
AMOUNTS LOOK TO BE FAIRLY LIGHT...THOUGH. THIS FRONTAL BOUNDARY
DROPPING SOUTH...925MB TEMPS ONLY TOPPING OUT FROM 10-12C AT 00Z
MONDAY...A BREEZY NORTH WIND AND A DECENT AMOUNT OF SUN NOT
OCCURRING UNTIL LATE IN THE DAY WILL YIELD MUCH COOLER CONDITIONS
COMPARED TO TODAY.
MODELS REMAIN IN GOOD AGREEMENT IN BUILDING HIGH PRESSURE INTO THE
FORECAST AREA FOR SUNDAY NIGHT THROUGH TUESDAY. THIS IS IN RESPONSE
TO THE UPPER RIDGE OVER THE WESTERN THIRD OF THE U.S. MARCHING EAST
INTO MN AND IA BY 12Z TUE. THE MAIN CENTER OF THE HIGH LOOKS TO
TRACK JUST SOUTH OF THE AREA...BUT THE GRADIENT RELAXES ENOUGH TO
ALLOW FOR DECOUPLING BOTH NIGHTS. SOME CLOUDS COULD DRIFT ACROSS
BOTH NIGHTS...BUT IT APPEARS ENOUGH PERIOD OF CLEAR SKIES SHOULD
EXIST FOR VALLEY FOG TO FORM...ESPECIALLY IN THE TRIBUTARIES. SUNDAY
NIGHT WILL BE THE COOLER OF THE TWO NIGHTS DUE TO AIRMASS
MODIFICATION TAKING PLACE ON MONDAY. THE TYPICAL COLD SPOTS IN
CENTRAL WI COULD DIP INTO THE MID/UPPER 30S SUNDAY NIGHT. 925MB
TEMPS OF 12-14C ON MONDAY WITH MORE SUN WILL ALLOW HIGHS TO TOP OUT
IN THE 60S TO LOW 70S...WARMEST IN VALLEYS. THESE 925MB TEMPS CLIMB
ANOTHER 1-2C ON TUESDAY...RESULTING IN A SIMILAR BUMP UP IN HIGHS.
IN GENERAL THE WEATHER REMAINS FAIRLY QUIET FROM TUESDAY NIGHT RIGHT
INTO NEXT WEEKEND...THANKS TO SIGNIFICANT UPPER RIDGING BUILDING UP
OVER THE EASTERN TWO THIRDS OF THE U.S.. IN FACT...MOST LONG RANGE
GUIDANCE IS SUGGESTING A 590 DAM 500MB HIGH TO FORM OVER MICHIGAN BY
00Z SATURDAY...WHICH WOULD BE ABOUT 2 STANDARD DEVIATIONS ABOVE
NORMAL. THIS IS ALL A RESULT OF A VERY DEEP TROUGH DEVELOPING ALONG
THE WEST COAST OF THE U.S....SOMETHING THAT HASNT BEEN SEEN FOR
QUITE SOME TIME. THE ONLY REAL ISSUE TO WORRY ABOUT IS THE CURRENT
UPPER LOW OFF THE CALIFORNIA COAST...WHICH MODELS TRY TO BRING
THROUGH THE FORECAST AREA IN A WEAKENING STATE CENTERED AROUND
WEDNESDAY. HAVE MAINTAINED SOME LOW PRECIPITATION CHANCES ASSOCIATED
WITH THIS FEATURE. DESPITE THE RISING 500MB HEIGHTS...IT TAKES
AWHILE FOR A SIMILAR RESPONSE TO 850MB TEMPS...PARTIALLY DUE TO THAT
UPPER LOW LIFTING THROUGH. THUS...TEMPERATURES HOLD NEAR SEASONABLE
NORMALS UNTIL THE END OF THE WEEK. FRIDAY...SATURDAY AND SUNDAY ALL
LOOK ABOVE NORMAL WITH HIGHS POSSIBLY APPROACHING 80.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1145 AM CDT SAT SEP 20 2014
SFC FRONT SLIDING ACROSS THE REGION...WITH SATELLITE IMAGERY
POINTING TO SKC SKIES POST FRONT. EXPECTING VFR CONDITIONS THROUGH
THE AFTERNOON INTO THE EARLY EVENING.
AN UPPER LEVEL SHORTWAVE TROUGH WILL DRIVE SOUTHEAST ACROSS THE
NORTHERN PLAINS AND THEN THROUGH THE UPPER MISSISSIPPI RIVER VALLEY
TONIGHT. A COLD FRONT AT THE SFC WILL ACCOMPANY THE SHORTWAVE...AND
HELP FIRE A LINE OF SHOWERS/ISOLATED THUNDERSTORMS AS IT MOVES
THROUGH. COULD SEE SOME HIGHER GUSTS AROUND THE STRONGER STORMS -
WITH AN ISOLATED SEVERE THREAT EARLY IN THE EVENING.
UPSTREAM OBS WITH THE SHORTWAVE POINT TO AN AREA OF MVFR CIGS IN THE
2-2.5 KFT RANGE. MODEL RH FIELDS AND BUFKIT SOUNDINGS FAVOR THIS
TOO...ESPECIALLY ALONG AND EAST OF THE MISSISSIPPI RIVER. MOST OF
THIS APPEARS POST THE APPROX 3 HOUR WINDOW WHEN A -SHRA/TS THREAT IS
HIGHLIGHTED. SPEAKING OF WHICH...WITH INSTABILITY MINIMAL AT
BEST...WILL KEEP MENTION TO -SHRA RATHER THAN -TSRA. DYNAMICS DO
APPEAR STRONG ENOUGH FOR SOME ISOLD THUNDER...BUT NOT CONFIDENT
ENOUGH TO INCLUDE IN TAFS AT THIS TIME.
FRONT LIKELY LINGERS ACROSS THE REGION FOR THE BETTER PART OF
SUNDAY...BEFORE HIGH PRESSURE AND SUBSIDENCE WORKS IN BY THE
EVENING. KLSE COULD BE UNDER MVFR CLOUDS FOR THE BETTER PART OF THE
MORNING...POTENTIALLY LINGERING THROUGH THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RIECK