Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/29/15
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
731 PM EDT FRI AUG 28 2015
.UPDATE...
23Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE EASTERN UNITED
STATES LONGWAVE TROUGH THAT WAS IN PLACE 24 HOURS AGO...HAS
WEAKENED AND CLOSED OFF INTO A SEMI-CLOSED LOW OVER THE NORTH-
CENTRAL GULF COAST. THIS UPPER LOW...HOWEVER...IS STILL THE
DIVIDER BETWEEN A SIGNIFICANT SWATH OF DRY MID/UPPER LEVEL AIR
OVER THE CENTRAL/WESTERN GULF...AND DEEP MOISTURE IN PLACE OVER
THE EASTERN GULF OF MEXICO AND FLORIDA PENINSULA.
IT WAS ANOTHER WET DAY ACROSS THE PENINSULA UNDER THIS ABUNDANT
ATMOSPHERIC MOISTURE...WITH WIDESPREAD COVERAGE OF SHOWERS AND
STORMS...AND MORE HEFTY RAINFALL TOTALS ACROSS PORTIONS OF OUR
SOUTHWEST AND SOUTH-CENTRAL ZONES. SEEMS TO BE THE STORY FOR THE
SUMMER...AND RAIN CHANCES WILL NOT BE DECREASING FOR SATURDAY.
BEST CHANCES ON SATURDAY FOR GETTING ANYTHING DONE OUTDOORS WILL
BE IN THE MORNING...AS RAIN CHANCE QUICKLY INCREASE FROM MIDDAY
ON.
&&
.AVIATION...
29/00Z-30/00Z. EXISTING SHRA/TSRA SHOULD PRIMARILY STAY NORTH AND
EAST OF TERMINALS THROUGH THIS EVENING. ACTIVITY WILL DIMINISH
OVERNIGHT...AND EXPECT VFR CONDITIONS WITH PREVAILING LIGHT E/SE
WINDS OVERNIGHT. SCT TSRA LIKELY TO DEVELOP OVER THE WATERS EARLY
SAT...WITH VCSH POSSIBLE AT KTPA/KPIE. THEN...SCT TSRA LIKELY TO
DEVELOP FROM 18Z TO 21Z...LINGERING INTO THE LATE AFTERNOON.
CIGS/VSBYS TO REMAIN VFR EXCEPT IN TSRA...WHERE BRIEF MVFR/IFR CIGS
MAY OCCUR.
&&
.MARINE...
THE GRADIENT ACROSS THE EASTERN GULF OF MEXICO WILL REMAIN WEAK
THROUGH SATURDAY ON THE FAR SOUTHERN PERIPHERY OF A HIGH PRESSURE
RIDGE CENTERED ACROSS THE MID-ATLANTIC STATES. WINDS AND SEAS WILL
REMAIN LOW THROUGH SATURDAY AWAY FROM SCATTERED TO NUMEROUS
SHOWERS AND STORMS. LATER SUNDAY INTO MONDAY THE FORECAST FOR THE
EASTERN GULF WILL BE HIGHLY DEPENDENT ON THE EVENTUAL TRACK AND
STRENGTH OF TROPICAL STORM ERIKA. THE TREND AS BEEN FOR A WEAKER
AND WEAKER STORM...BUT THOSE PLANNING ACTIVITIES ON THE GULF
DURING THE SECOND HALF OF THE WEEKEND SHOULD CONTINUE TO CLOSELY
MONITOR THE PROGRESS OF ERIKA.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 91 77 91 / 70 50 30 60
FMY 76 93 77 90 / 90 70 30 60
GIF 75 92 75 90 / 70 60 30 70
SRQ 75 91 76 91 / 40 50 30 50
BKV 74 91 73 91 / 90 50 30 60
SPG 79 91 78 91 / 70 50 30 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...AUSTIN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1047 PM EDT FRI AUG 28 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST THROUGH
TONIGHT...WITH DRY SURFACE HIGH PRESSURE REMAINING ANCHORED OVER
THE WESTERN AND CENTRAL CAROLINAS. INCREASING ATMOSPHERIC
MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN AND WESTERN
PORTIONS OF OUR REGION LATE SATURDAY...AND INTO REMAINING AREAS
SUNDAY. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN
FLORIDA SUNDAY NIGHT. REFER TO THE LATEST ADVISORY ON ERIKA
ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.NEAR TERM /THROUGH SATURDAY/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST FOR THE OVERNIGHT
HOURS. WV LOOP SHOWS A TROUGH ALONG THE CENTRAL GULF COAST WITH
GA/SC ON THE FRONT SIDE WITH A SOUTH/SOUTHWEST MID/UPPER LEVEL
FLOW. EXPECT THE WEAK FRONTAL BOUNDARY TO REMAIN STALLED OFF THE
SC COAST. AT THE SURFACE...HIGH PRESSURE TO OUR NORTH WILL
CONTINUE TO PROVIDE A NORTHEASTERLY/EASTERLY FLOW WILL PERSIST
OVER THE FORECAST AREA. EXPECT MAINLY DRY CONDITIONS UNDER PARTLY
TO MOSTLY CLOUDY SKIES AT TIMES WITH MOST MID/UPPER FLOW. OVERNIGHT
LOWS RANGING FROM THE MIDDLE 60S NORTH TO AROUND 70 SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
MEAN UPPER TROUGH TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED
TO OUR E AND SE. SHORTWAVE ENERGY MOVING EAST INTO THE MIDWEST
SAT/SUN WILL ALLOW UPPER ENERGY AND MOISTURE TO SLOWLY SHIFT
NORTH FROM THE GULF INTO OUR REGION. WITH THE EXCEPTION OF THE
NAM...MODELS CONTINUE TO TREND SLOWER WITH MOISTURE RETURN...AND
MAINLY RELEGATE IT TO THE S AND W FA SATURDAY...AS SURFACE HIGH
PRESSURE AND DRIER AIR REMAINS ENTRENCHED OVER THE WESTERN AND
CENTRAL CAROLINAS. THINK SLIGHT CHANCE POPS BY AFTERNOON FOR THE
S/W FA LOOK OK SATURDAY. MOISTURE EXPECTED TO CONTINUE TRENDING
SLOWLY NORTH SATURDAY NIGHT INTO SUNDAY...WITH INDICATIONS OF WEAK
SURFACE HIGH PRESSURE AND DRIER AIR STILL TRYING TO HANG TOUGH
OVER THE WESTERN CAROLINAS. MODELS INDICATE A POP GRADIENT OVER
OUR FA SUNDAY WITH LOWER POPS NORTH/HIGHER POPS SOUTH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST.
MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL
CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO S FLORIDA
BY LATE SUN...AND NORTHWARD INTO N FL/S GA VICINITY BY WED. EVEN
WITHOUT THE CYCLONE IN PLAY...IT APPEARS SUFFICIENT ATMOSPHERIC
MOISTURE WOULD PROVIDE PREMISE FOR SCATTERED DIURNAL CONVECTION
OVER OUR FA ANYWAY. DUE TO UNCERTAINTIES REGARDING POSSIBLE
IMPACT OF ERIKA ON OUR REGION...WILL CONTINUE TO MAINTAIN ONGOING
FORECAST OF CHANCE POPS...TRENDED A LITTLE HIGHER TO THE SOUTH.
GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
LINGERING LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY LEAD TO
STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE NAM MOS
INDICATED MVFR OR IFR CONDITIONS 06Z TO 15Z. THE GFS MOS PLUS SREF
AND HRRR GUIDANCE GENERALLY MAINTAINED VFR CONDITIONS. WE LEANED
TOWARD THE MORE OPTIMISTIC GUIDANCE BASED ON UPPER MOISTURE
STREAMING INTO THE AREA LIMITING NET RADIATIONAL COOLING AND
SURFACE HIGH PRESSURE TO THE NORTH PUSHING DRY AIR TOWARD THE
AREA. AN INCREASE IN MOISTURE AND HEATING MAY HELP SUPPORT
THUNDERSTORMS IN THE AFTERNOON BUT EXPECT SCATTERED COVERAGE WITH
THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS
TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1031 PM EDT FRI AUG 28 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST THROUGH
TONIGHT...WITH DRY SURFACE HIGH PRESSURE REMAINING ANCHORED OVER
THE WESTERN AND CENTRAL CAROLINAS. INCREASING ATMOSPHERIC
MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN AND WESTERN
PORTIONS OF OUR REGION LATE SATURDAY...AND INTO REMAINING AREAS
SUNDAY. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN
FLORIDA SUNDAY NIGHT. REFER TO THE LATEST ADVISORY ON ERIKA
ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.NEAR TERM /THROUGH SATURDAY/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST FOR THE OVERNIGHT
HOURS. A WEAK FRONTAL BOUNDARY WILL REMAIN STALLED OFF THE SC
COAST. AS A RESULT...A NORTHEASTERLY/EASTERLY FLOW WILL PERSIST
OVER THE FORECAST AREA. EXPECT MAINLY DRY CONDITIONS UNDER PARTLY
CLOUDY SKIES. OVERNIGHT LOWS RANGING FROM THE MIDDLE 60S NORTH TO
AROUND 70 SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
MEAN UPPER TROUGH TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED
TO OUR E AND SE. SHORTWAVE ENERGY MOVING EAST INTO THE MIDWEST
SAT/SUN WILL ALLOW UPPER ENERGY AND MOISTURE TO SLOWLY SHIFT
NORTH FROM THE GULF INTO OUR REGION. WITH THE EXCEPTION OF THE
NAM...MODELS CONTINUE TO TREND SLOWER WITH MOISTURE RETURN...AND
MAINLY RELEGATE IT TO THE S AND W FA SATURDAY...AS SURFACE HIGH
PRESSURE AND DRIER AIR REMAINS ENTRENCHED OVER THE WESTERN AND
CENTRAL CAROLINAS. THINK SLIGHT CHANCE POPS BY AFTERNOON FOR THE
S/W FA LOOK OK SATURDAY. MOISTURE EXPECTED TO CONTINUE TRENDING
SLOWLY NORTH SATURDAY NIGHT INTO SUNDAY...WITH INDICATIONS OF WEAK
SURFACE HIGH PRESSURE AND DRIER AIR STILL TRYING TO HANG TOUGH
OVER THE WESTERN CAROLINAS. MODELS INDICATE A POP GRADIENT OVER
OUR FA SUNDAY WITH LOWER POPS NORTH/HIGHER POPS SOUTH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST.
MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL
CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO S FLORIDA
BY LATE SUN...AND NORTHWARD INTO N FL/S GA VICINITY BY WED. EVEN
WITHOUT THE CYCLONE IN PLAY...IT APPEARS SUFFICIENT ATMOSPHERIC
MOISTURE WOULD PROVIDE PREMISE FOR SCATTERED DIURNAL CONVECTION
OVER OUR FA ANYWAY. DUE TO UNCERTAINTIES REGARDING POSSIBLE
IMPACT OF ERIKA ON OUR REGION...WILL CONTINUE TO MAINTAIN ONGOING
FORECAST OF CHANCE POPS...TRENDED A LITTLE HIGHER TO THE SOUTH.
GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
LINGERING LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY LEAD TO
STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE NAM MOS
INDICATED MVFR OR IFR CONDITIONS 06Z TO 15Z. THE GFS MOS PLUS SREF
AND HRRR GUIDANCE GENERALLY MAINTAINED VFR CONDITIONS. WE LEANED
TOWARD THE MORE OPTIMISTIC GUIDANCE BASED ON UPPER MOISTURE
STREAMING INTO THE AREA LIMITING NET RADIATIONAL COOLING AND
SURFACE HIGH PRESSURE TO THE NORTH PUSHING DRY AIR TOWARD THE
AREA. AN INCREASE IN MOISTURE AND HEATING MAY HELP SUPPORT
THUNDERSTORMS IN THE AFTERNOON BUT EXPECT SCATTERED COVERAGE WITH
THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS
TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
726 PM EDT FRI AUG 28 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST THROUGH
TONIGHT...WITH DRY SURFACE HIGH PRESSURE REMAINING ANCHORED OVER
THE WESTERN AND CENTRAL CAROLINAS. INCREASING ATMOSPHERIC
MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN AND WESTERN
PORTIONS OF OUR REGION LATE SATURDAY...AND INTO REMAINING AREAS
SUNDAY. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN
FLORIDA SUNDAY NIGHT. REFER TO THE LATEST ADVISORY ON ERIKA
ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.NEAR TERM /THROUGH SATURDAY/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST FOR THE EVENING
AND OVERNIGHT HOURS. A WEAK FRONTAL BOUNDARY WILL REMAIN STALLED
OFF THE SC COAST. AS A RESULT...A NORTHEASTERLY/EASTERLY FLOW WILL
PERSIST OVER THE FORECAST AREA. LATEST RADAR LOOP SHOWING A FEW
SHOWERS MAINLY ALONG THE COAST AND ACROSS CNTRL/SRN GA. SLIGHT
CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS APPROPRIATE
FOR THE EARLY EVENING HOURS.
OVERNIGHT...MAINLY DRY CONDITIONS UNDER PARTLY CLOUDY SKIES.
OVERNIGHT LOWS RANGING FROM THE MIDDLE 60S NORTH TO AROUND 70
SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
MEAN UPPER TROUGH TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED
TO OUR E AND SE. SHORTWAVE ENERGY MOVING EAST INTO THE MIDWEST
SAT/SUN WILL ALLOW UPPER ENERGY AND MOISTURE TO SLOWLY SHIFT
NORTH FROM THE GULF INTO OUR REGION. WITH THE EXCEPTION OF THE
NAM...MODELS CONTINUE TO TREND SLOWER WITH MOISTURE RETURN...AND
MAINLY RELEGATE IT TO THE S AND W FA SATURDAY...AS SURFACE HIGH
PRESSURE AND DRIER AIR REMAINS ENTRENCHED OVER THE WESTERN AND
CENTRAL CAROLINAS. THINK SLIGHT CHANCE POPS BY AFTERNOON FOR THE
S/W FA LOOK OK SATURDAY. MOISTURE EXPECTED TO CONTINUE TRENDING
SLOWLY NORTH SATURDAY NIGHT INTO SUNDAY...WITH INDICATIONS OF WEAK
SURFACE HIGH PRESSURE AND DRIER AIR STILL TRYING TO HANG TOUGH
OVER THE WESTERN CAROLINAS. MODELS INDICATE A POP GRADIENT OVER
OUR FA SUNDAY WITH LOWER POPS NORTH/HIGHER POPS SOUTH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST.
MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL
CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO S FLORIDA
BY LATE SUN...AND NORTHWARD INTO N FL/S GA VICINITY BY WED. EVEN
WITHOUT THE CYCLONE IN PLAY...IT APPEARS SUFFICIENT ATMOSPHERIC
MOISTURE WOULD PROVIDE PREMISE FOR SCATTERED DIURNAL CONVECTION
OVER OUR FA ANYWAY. DUE TO UNCERTAINTIES REGARDING POSSIBLE
IMPACT OF ERIKA ON OUR REGION...WILL CONTINUE TO MAINTAIN ONGOING
FORECAST OF CHANCE POPS...TRENDED A LITTLE HIGHER TO THE SOUTH.
GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LINGERING LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY LEAD TO
STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE NAM MOS
INDICATED MVFR OR IFR CONDITIONS 06Z TO 15Z. THE GFS MOS PLUS SREF
AND HRRR GUIDANCE GENERALLY MAINTAINED VFR CONDITIONS. WE LEANED
TOWARD THE MORE OPTIMISTIC GUIDANCE BASED ON UPPER MOISTURE
STREAMING INTO THE AREA LIMITING NET RADIATIONAL COOLING AND
SURFACE HIGH PRESSURE TO THE NORTH PUSHING DRY AIR TOWARD THE
AREA. AN INCREASE IN MOISTURE AND HEATING MAY HELP SUPPORT
THUNDERSTORMS SATURDAY AFTERNOON BUT EXPECT SCATTERED COVERAGE
WITH THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT
THIS TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
714 AM EDT THU AUG 27 2015
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN ACROSS THE AREA THROUGH TONIGHT.
HIGH PRESSURE WILL SETTLE IN NORTH OF THE REGION INTO FRIDAY
BEFORE MOVING OFF THE EAST COAST THIS WEEKEND. TROPICAL STORM
ERIKA COULD IMPACT THE SOUTHEAST U.S. BY EARLY OR MID NEXT WEEK.
REFER TO THE LATEST ADVISORY ON ERIKA ISSUED BY THE NATIONAL
HURRICANE CENTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE SUNRISE UPDATE...ADJUSTED NEAR TERM POPS TO MATCH
GOING RADAR TRENDS. BEST CHANCES OF RAIN THROUGH 9 AM WILL BE OVER
COASTAL CHARLESTON COUNTY AND THE ADJACENT COASTAL WATERS.
CEILINGS HAVE DROPPED TO 600-800 FEET AT KOGB AND KMNI...SOME OF
WHICH IS BLEEDING INTO THE NORTHERN PARTS OF COLLETON...DORCHESTER
AND BERKELEY COUNTIES. THE REST OF THE FORECAST IS UNCHANGED.
THE STATIONARY FRONT HAS BUCKLED BACK INLAND AWAY FROM THE COAST
EARLY THIS MORNING IN RESPONSE TO WEAK LOW PRESSURE RETROGRADING
INTO INTERIOR SOUTHEAST GEORGIA. MODELS SHOW THE STATIONARY FRONT
ESSENTIALLY BISECTING SOUTHEAST SOUTHEAST SOUTH CAROLINA AND
SOUTHEAST GEORGIA TODAY AS THE WESTERN EDGE OF A RIBBON OF HIGHER
850-700 HPA THETA-E AIR NUDGES WEST. THIS COUPLED WITH UPPER
DIFLUENCE INDUCED BY THE RIGHT ENTRANCE REGION OF A SUBTROPICAL
JET STREAK POSITIONED OVER THE CAROLINA PIEDMONT WILL SUPPORT
SCATTERED SHOWERS/TSTMS LATER THIS MORNING AND CONTINUING INTO THE
AFTERNOON HOURS. THE RAP AND NSSL-WRF APPEAR TO HAVE THE BEST
HANDLE ON THE EXPECTED EVOLUTION OF CONVECTION TODAY...BUT THERE
ARE DEFINITELY SOME TEMPORAL AND SPATIAL DIFFERENCES NOTED. WILL
GO WITH A 30-50 POP REGIME FOR TODAY WITH THE HIGHEST GRIDDED POPS
PLACED ROUGHLY ALONG AND SOUTH OF A NORTH CHARLESTON-
HENDERSONVILLE-SPRINGFIELD-GLENNVILLE LINE. THIS INCLUDES BOTH THE
CHARLESTON AND SAVANNAH METRO AREAS. INITIALLY THE AIRMASS WEST OF
THE FRONT WILL LIKELY BE TOO DRY TO SUPPORT DEEP CONVECTION...BUT
THIS WILL CHANGE AS THE AFTERNOON PROGRESSES AS MID-LEVEL THETA-E
INCREASES. WILL CAP POPS AT 20-30 PERCENT WELL INLAND FOR NOW.
HIGHS WILL RANGE FROM THE UPPER 80S TO LOWER 90S INLAND WITH
COOLER CONDITIONS AT THE BEACHES. THE PRIMARY HAZARD FOR TODAY
LOOKS TO BE LOCALLY HEAVY RAINFALL WITH A FEW STRONG TSTMS BEING
POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...CONVECTION IS EXPECTED TO DIMINISH SLOWLY THIS
EVENING WITH ADDITIONAL SHOWERS/TSTMS DEVELOPING OVER THE COASTAL
WATERS IN RESPONSE TO LOW-LEVEL CONVERGENCE SHIFTING BACK TO THE
WESTERN WALL OF THE GULF STREAM. WILL NEED TO KEEP 20-40 PERCENT
POPS FOR MUCH OF THE NIGHT...HIGHEST AT THE COAST...AS THE LOW-
LEVEL FLOW REGIME WILL FAVOR SOME OF THIS ACTIVITY MAKING IT
INLAND. LOWS WILL RANGE FROM THE LOWER 70S INLAND WITH UPPER
70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON.
FRIDAY THROUGH SUNDAY...AT UPPER LEVELS....THE REGION WILL REMAIN
BETWEEN A WEAKENING TROUGH TO THE WEST OVER THE MS RIVER VALLEY
AND A STRONG ATLANTIC RIDGE TO THE EAST. AT THE SURFACE...HIGH
PRESSURE CENTERED WELL NORTH OF THE AREA ON FRIDAY...WILL SHIFT
EAST INTO THE ATLANTIC ON SATURDAY AND SUNDAY. THE LOW LEVEL FLOW
WILL BE EASTERLY ON FRIDAY...THEN VEER TO SOUTHEAST SATURDAY AND
SUNDAY. DEEP LAYER MOISTURE WILL INCREASE THROUGH THE PERIOD AS
EAST- SOUTHEAST FLOW ADVECTS TROPICAL MOISTURE INTO THE AREA. WENT
LOW END CHANCE POPS FOR MAINLY AFTERNOON CONVECTION ON
FRIDAY...THEN INCREASED TO HIGH END CHANCE FOR BOTH SATURDAY AND
SUNDAY. TEMPERATURES ARE EXPECTED TO BE NEAR TO SLIGHTLY ABOVE
NORMAL THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
ALL EYES WILL BE FOCUSING ON THE FATE OF ERIKA DURING THIS PERIOD.
THE LATEST NHC FORECAST FOR ERIKA HAS THE CENTER OF THE STORM
EMERGING FROM THE NORTHERN BAHAMAS LATER MONDAY...THEN MOVING
NORTHWARD TOWARD OUR ATLANTIC WATERS ON TUESDAY. THE OFFICIAL NHC
TRACK IS PRETTY CLOSE TO THE LATEST RUN OF THE GFS. IT IS STILL TOO
EARLY TO SPECULATE ON ANY POTENTIAL IMPACTS FROM ERIKA IN OUR AREA
DUE TO A SIGNIFICANT AMOUNT OF UNCERTAINTY WITH BOTH THE TRACK AND
INTENSITY OF THIS SYSTEM.
HAVE GRADUALLY INCREASED POPS MONDAY THROUGH WEDNESDAY...WITH HIGH
END CHANCE TO LOW END LIKELY ON MONDAY AND TUESDAY. DUE TO
UNCERTAINTY IN THE TRACK...HAVE KEPT HIGH END CHANCE FOR NOW ON
WEDNESDAY. BY THURSDAY...STARTED TO TREND POPS DOWN ASSUMING ERIKA
MOVES WELL AWAY FROM OUR REGION BY THEN.
TEMPERATURES NEAR NORMAL THROUGH THE PERIOD.
PLEASE CONTINUE TO MONITOR THE LATEST FORECASTS FROM THE NATIONAL
HURRICANE CENTER AND OUR OFFICE CONCERNING ERIKA.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
STRATUS AT KOGB AND KMNI WILL REMAIN NORTHWEST OF KCHS. VFR THIS
MORNING AT BOTH KCHS AND KSAV. SCATTERED SHOWERS/TSTMS ARE
EXPECTED TO IMPACT THE AREA TODAY. THERE ARE STILL SOME
TIMING/SPATIAL DIFFERENCES NOTED THE VARIOUS MODEL DATA...BUT
ODDS FAVOR KSAV FOR IMPACTS. WILL CARRY TEMPO 4SM -TSRA AT KSAV
18-21Z FOR NOW. TSRA MAY NEED TO BE ADDED TO KCHS IF CONFIDENCE
INCREASES.
EXTENDED AVIATION OUTLOOK...FRIDAY THROUGH MONDAY...EXPECT VFR TO
DOMINATE WITH BRIEF PERIODS OF FLIGHT RESTRICTIONS POSSIBLE IN
SCATTERED SHOWERS AND THUNDERSTORMS. LATER MONDAY THROUGH MID
WEEK...THE FORECAST HIGHLY DEPENDS ON THE EVENTUAL TRACK AND
INTENSITY OF ERIKA. THE LATEST TRACK FROM NHC BRINGS ERIKA TOWARD
OUR REGION TUESDAY AND WEDNESDAY. EXPECT INCREASING CHANCES FOR
CONVECTION AND FLIGHT RESTRICTIONS... ESPECIALLY LATER TUESDAY AND
WEDNESDAY...ASSUMING THIS WILL BE THE TIME FRAME OF CLOSEST
APPROACH OF ERIKA. ALSO WIND SPEEDS AND DIRECTIONS WILL BE HIGHLY
DEPENDENT ON WHERE ERIKA TRACKS. STAY TUNED TO THE LATEST
FORECASTS FROM THE NATIONAL HURRICANE CENTER AND OUR OFFICE
CONCERNING ERIKA.
&&
.MARINE...
TODAY...LIGHT WINDS WILL BECOME SOUTHEAST TODAY AS THE STATIONARY
FRONT MEANDERS FARTHER INLAND AND THE SEA BREEZE CIRCULATION TAKES
HOLD. SPEEDS LOOK TO MAX OUT AT 10-15 KT WITH SEAS 1-3 FT. TSTMS
COULD POSE A RISK FOR MARINERS WITH WIND GUSTS IN EXCESS OF 35
KT...CLOUD TO WATER LIGHTNING AND VSBYS LESS THAN 1 NM IN HEAVY
RAIN.
TONIGHT...SOUTHEAST WINDS WILL PREVAIL WITH WINDS GENERALLY 10-15
KT WITH SEAS 1-3 FT. TSTMS COULD POSE A RISK FOR MARINERS WITH
WIND GUSTS IN EXCESS OF 35 KT...CLOUD TO WATER LIGHTNING AND
VSBYS LESS THAN 1 NM IN HEAVY RAIN.
THURSDAY THROUGH MONDAY...NO HIGHLIGHTS EXPECTED THROUGH MUCH OF
MONDAY WITH WINDS GENERALLY 15 KTS OR LESS AND SEAS LESS THAN 5
FEET. ATLANTIC HIGH PRESSURE WILL REMAIN CENTERED EAST AND NORTH
OF THE AREA THROUGH MONDAY...WITH EAST WINDS ON FRIDAY...VEERING
TO SOUTHEAST SATURDAY THROUGH MONDAY.
LATER MONDAY THROUGH WEDNESDAY...THE FORECAST BECOMES HIGHLY
DEPENDENT ON THE EVENTUAL TRACK AND INTENSITY OF ERIKA. THE
LATEST NHC FORECAST HAS ERIKA APPROACHING THE WATERS LATER
TUESDAY. HAVE STARTED TO TREND WINDS AND SEAS UP BY MONDAY NIGHT
AND TUESDAY...BUT THERE IS A LOT OF UNCERTAINTY WITH THIS
FORECAST. FOR NOW...HAVE CAPED WINDS AT 30 KTS OR LESS TUESDAY AND
WEDNESDAY...WITH SEAS 10-15 FEET...MAINLY OFFSHORE.
PLEASE STAY TUNED TO THE LATEST FORECASTS FROM THE NATIONAL
HURRICANE CENTER AND OUR OFFICE CONCERNING ERIKA.
&&
.TIDES/COASTAL FLOODING...
THIS EVENING...CURRENT TIDE TRENDS SUGGEST TIDE LEVELS COULD PEAK
NEAR OR JUST ABOVE 7.0 FT MLLW IN THE CHARLESTON HARBOR. WITH THE
FAIRLY LIGHT WIND REGIME IN PLACE...IT IS POSSIBLE TIDES MAY FALL
JUST SHORT AS GUIDANCE TENDS TO RUN A BIT TOO HIGH THIS FAR OUT IN
THIS KIND OF REGIME. HOWEVER...A COASTAL FLOOD ADVISORY COULD
STILL BE NEEDED FOR PARTS OF THE LOWER SOUTH CAROLINA COAST LATER
TODAY. TRENDS SUGGEST TIDES WILL REMAIN BELOW ADVISORY CRITERIA
FORT PULASKI AND THE GEORGIA COAST.
FRIDAY THROUGH SUNDAY...ASTRONOMICAL TIDES WILL BE HIGH FRIDAY
THROUGH MID NEXT WEEK. EVEN WITHOUT ANY EFFECTS FROM
ERIKA...EXTRA- TROPICAL SURGE GUIDANCE SHOWS TIDES REACHING MINOR
COASTAL FLOOD LEVELS DURING THE MAJOR HIGH TIDES FOR FRIDAY AND
SATURDAY. EASTERLY LOW LEVEL FLOW FRIDAY AND SATURDAY WILL HELP TO
INCREASE TIDE LEVELS. WINDS BECOME MORE SOUTHEAST BY
SUNDAY...WHICH MAY NOT BE QUITE AS CONDUCIVE FOR PUSHING TIDE
LEVELS HIGHER...BUT WILL CONTINUE MONITORING THE POTENTIAL FOR
MINOR COASTAL FLOODING.
MONDAY THROUGH WEDNESDAY...ASTRONOMICAL TIDE LEVELS WILL REMAIN MUCH
HIGHER THAN NORMAL...AND IF THE LATEST FORECAST FROM NHC FOR ERIKA
HOLDS...WE WILL HAVE THE POTENTIAL FOR MORE SIGNIFICANT RISES IN THE
TIDES ALONG WITH SOME COASTAL FLOODING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/RFM
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
440 AM EDT THU AUG 27 2015
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN ACROSS THE AREA THROUGH TONIGHT.
HIGH PRESSURE WILL SETTLE IN NORTH OF THE REGION INTO FRIDAY
BEFORE MOVING OFF THE EAST COAST THIS WEEKEND. TROPICAL STORM
ERIKA COULD IMPACT THE SOUTHEAST U.S. BY EARLY OR MID NEXT WEEK.
REFER TO THE LATEST ADVISORY ON ERIKA ISSUED BY THE NATIONAL
HURRICANE CENTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THROUGH SUNRISE...AN IMPRESSIVE BAND OF STRONG TSTMS HAS DEVELOPED
ALONG AND JUST OFF THE SOUTHERN SOUTH CAROLINA COAST EARLY THIS
MORNING. NONE OF THE HIGHER RESOLUTION MODELS PICKED UP ON THIS
CONVECTION. EXPECT ACTIVITY TO GRADUALLY WIND DOWN AS SUNRISE
APPROACHES AND THE ATMOSPHERE OVER THE COASTAL WATERS BECOMES
INCREASINGLY OVERTURNED. THERE WILL BE A RISK FOR HEAVY RAIN
THROUGH SUNRISE...ESPECIALLY ALONG THE COLLETON AND CHARLESTON
COUNTY COASTS...ALONG WITH A RISK FOR FLOODING. FARTHER
INLAND...WATCHING FOR POSSIBLE LOW STRATUS AND FOG OOZING IN FROM
THE EASTERN MIDLANDS. NAM12 1000 HPA CONDENSATION PRESSURE
DEFICITS SHOW AREAS FROM WALTERBORO TO MONCKS CORNER HAVING THE
BEST CHANCES FOR LOW STRATUS AND POSSIBLY SOME REDUCTIONS IN
VISIBILITIES...BUT ANY FOG THAT DOES FORM SHOULD REMAIN FAIRLY
LIGHT GIVEN THE EXTENSIVE MID/HIGH CLOUD CANOPIES THAT ARE IN
PLACE.
TODAY...THE STATIONARY FRONT HAS BUCKLED BACK INLAND AWAY FROM THE
COAST EARLY THIS MORNING IN RESPONSE TO WEAK LOW PRESSURE
RETROGRADING INTO INTERIOR SOUTHEAST GEORGIA. MODELS SHOW THE
STATIONARY FRONT ESSENTIALLY BISECTING SOUTHEAST SOUTHEAST SOUTH
CAROLINA AND SOUTHEAST GEORGIA TODAY AS THE WESTERN EDGE OF A
RIBBON OF HIGHER 850-700 HPA THETA-E AIR NUDGES WEST. THIS
COUPLED WITH UPPER DIFLUENCE INDUCED BY THE RIGHT ENTRANCE REGION
OF A SUBTROPICAL JET STREAK POSITIONED OVER THE CAROLINA PIEDMONT
WILL SUPPORT SCATTERED SHOWERS/TSTMS LATER THIS MORNING AND
CONTINUING INTO THE AFTERNOON HOURS. THE RAP AND NSSL-WRF APPEAR
TO HAVE THE BEST HANDLE ON THE EXPECTED EVOLUTION OF CONVECTION
TODAY...BUT THERE ARE DEFINITELY SOME TEMPORAL AND SPATIAL
DIFFERENCES NOTED. WILL GO WITH A 30-50 POP REGIME FOR TODAY WITH
THE HIGHEST GRIDDED POPS PLACED ROUGHLY ALONG AND SOUTH OF A NORTH
CHARLESTON-HENDERSONVILLE-SPRINGFIELD-GLENNVILLE LINE. THIS
INCLUDES BOTH THE CHARLESTON AND SAVANNAH METRO AREAS. INITIALLY
THE AIRMASS WEST OF THE FRONT WILL LIKELY BE TOO DRY TO SUPPORT
DEEP CONVECTION...BUT THIS WILL CHANGE AS THE AFTERNOON PROGRESSES
AS MID-LEVEL THETA-E INCREASES. WILL CAP POPS AT 20-30 PERCENT
WELL INLAND FOR NOW. HIGHS WILL RANGE FROM THE UPPER 80S TO LOWER
90S INLAND WITH COOLER CONDITIONS AT THE BEACHES. THE PRIMARY
HAZARD FOR TODAY LOOKS TO BE LOCALLY HEAVY RAINFALL WITH A FEW
STRONG TSTMS BEING POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...CONVECTION IS EXPECTED TO DIMINISH SLOWLY THIS
EVENING WITH ADDITIONAL SHOWERS/TSTMS DEVELOPING OVER THE COASTAL
WATERS IN RESPONSE TO LOW-LEVEL CONVERGENCE SHIFTING BACK TO THE
WESTERN WALL OF THE GULF STREAM. WILL NEED TO KEEP 20-40 PERCENT
POPS FOR MUCH OF THE NIGHT...HIGHEST AT THE COAST...AS THE LOW-
LEVEL FLOW REGIME WILL FAVOR SOME OF THIS ACTIVITY MAKING IT
INLAND. LOWS WILL RANGE FROM THE LOWER 70S INLAND WITH UPPER
70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON.
FRIDAY THROUGH SUNDAY...AT UPPER LEVELS....THE REGION WILL REMAIN
BETWEEN A WEAKENING TROUGH TO THE WEST OVER THE MS RIVER VALLEY
AND A STRONG ATLANTIC RIDGE TO THE EAST. AT THE SURFACE...HIGH
PRESSURE CENTERED WELL NORTH OF THE AREA ON FRIDAY...WILL SHIFT
EAST INTO THE ATLANTIC ON SATURDAY AND SUNDAY. THE LOW LEVEL FLOW
WILL BE EASTERLY ON FRIDAY...THEN VEER TO SOUTHEAST SATURDAY AND
SUNDAY. DEEP LAYER MOISTURE WILL INCREASE THROUGH THE PERIOD AS
EAST- SOUTHEAST FLOW ADVECTS TROPICAL MOISTURE INTO THE AREA. WENT
LOW END CHANCE POPS FOR MAINLY AFTERNOON CONVECTION ON
FRIDAY...THEN INCREASED TO HIGH END CHANCE FOR BOTH SATURDAY AND
SUNDAY. TEMPERATURES ARE EXPECTED TO BE NEAR TO SLIGHTLY ABOVE
NORMAL THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
ALL EYES WILL BE FOCUSING ON THE FATE OF ERIKA DURING THIS PERIOD.
THE LATEST NHC FORECAST FOR ERIKA HAS THE CENTER OF THE STORM
EMERGING FROM THE NORTHERN BAHAMAS LATER MONDAY...THEN MOVING
NORTHWARD TOWARD OUR ATLANTIC WATERS ON TUESDAY. THE OFFICIAL NHC
TRACK IS PRETTY CLOSE TO THE LATEST RUN OF THE GFS. IT IS STILL TOO
EARLY TO SPECULATE ON ANY POTENTIAL IMPACTS FROM ERIKA IN OUR AREA
DUE TO A SIGNIFICANT AMOUNT OF UNCERTAINTY WITH BOTH THE TRACK AND
INTENSITY OF THIS SYSTEM.
HAVE GRADUALLY INCREASED POPS MONDAY THROUGH WEDNESDAY...WITH HIGH
END CHANCE TO LOW END LIKELY ON MONDAY AND TUESDAY. DUE TO
UNCERTAINTY IN THE TRACK...HAVE KEPT HIGH END CHANCE FOR NOW ON
WEDNESDAY. BY THURSDAY...STARTED TO TREND POPS DOWN ASSUMING ERIKA
MOVES WELL AWAY FROM OUR REGION BY THEN.
TEMPERATURES NEAR NORMAL THROUGH THE PERIOD.
PLEASE CONTINUE TO MONITOR THE LATEST FORECASTS FROM THE NATIONAL
HURRICANE CENTER AND OUR OFFICE CONCERNING ERIKA.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THERE LOOKS TO BE TOO MUCH CLOUD COVER TO SUPPORT FOG AT EITHER
TERMINAL AND IT HAS BEEN REMOVED FOR THE 06Z TAF CYCLE. COULD SEE
SOME STRATUS WORK ITS WAY INTO KCHS PRIOR TO SUNRISE...BUT THE
BULK SHOULD REMAIN NORTH AND NORTHWEST OF THE TERMINAL. TSTM
ACTIVITY EAST OF KSAV WILL REMAIN EAST OF THE TERMINAL...BUT MAY
MAKE A RUN AT KCHS AFTER 09Z. WILL GO WITH VCTS FOR NOW THERE
FROM 09-12Z WITH BRIEF CIGS DROPPING TO BKN015. EXPECT VFR
OTHERWISE. SCATTERED SHOWERS/TSTMS WILL AFFECT THE REGION TODAY AS
A STATIONARY FRONT REMAINS INLAND FROM THE COAST. THERE ARE LARGE
DISCREPANCIES OF WHEN THE HIGHEST CHANCES FOR IMPACTS WILL OCCUR
AT EITHER TERMINAL. WILL THEREFORE LEAVE MENTION OF TSRA OUT OF
BOTH TERMINALS AFTER 12Z UNTIL A MORE DEFINITIVE TIMEFRAME CAN BE
ESTABLISHED.
EXTENDED AVIATION OUTLOOK...FRIDAY THROUGH MONDAY...EXPECT VFR TO
DOMINATE WITH BRIEF PERIODS OF FLIGHT RESTRICTIONS POSSIBLE IN
SCATTERED SHOWERS AND THUNDERSTORMS. LATER MONDAY THROUGH MID
WEEK...THE FORECAST HIGHLY DEPENDS ON THE EVENTUAL TRACK AND
INTENSITY OF ERIKA. THE LATEST TRACK FROM NHC BRINGS ERIKA TOWARD
OUR REGION TUESDAY AND WEDNESDAY. EXPECT INCREASING CHANCES FOR
CONVECTION AND FLIGHT RESTRICTIONS... ESPECIALLY LATER TUESDAY AND
WEDNESDAY...ASSUMING THIS WILL BE THE TIME FRAME OF CLOSEST
APPROACH OF ERIKA. ALSO WIND SPEEDS AND DIRECTIONS WILL BE HIGHLY
DEPENDENT ON WHERE ERIKA TRACKS. STAY TUNED TO THE LATEST
FORECASTS FROM THE NATIONAL HURRICANE CENTER AND OUR OFFICE
CONCERNING ERIKA.
&&
.MARINE...
TODAY...LIGHT WINDS WILL BECOME SOUTHEAST TODAY AS THE STATIONARY
FRONT MEANDERS FARTHER INLAND AND THE SEA BREEZE CIRCULATION TAKES
HOLD. SPEEDS LOOK TO MAX OUT AT 10-15 KT WITH SEAS 1-3 FT. TSTMS
COULD POSE A RISK FOR MARINERS WITH WIND GUSTS IN EXCESS OF 35
KT...CLOUD TO WATER LIGHTNING AND VSBYS LESS THAN 1 NM IN HEAVY
RAIN.
TONIGHT...SOUTHEAST WINDS WILL PREVAIL WITH WINDS GENERALLY 10-15
KT WITH SEAS 1-3 FT. TSTMS COULD POSE A RISK FOR MARINERS WITH
WIND GUSTS IN EXCESS OF 35 KT...CLOUD TO WATER LIGHTNING AND
VSBYS LESS THAN 1 NM IN HEAVY RAIN.
THURSDAY THROUGH MONDAY...NO HIGHLIGHTS EXPECTED THROUGH MUCH OF
MONDAY WITH WINDS GENERALLY 15 KTS OR LESS AND SEAS LESS THAN 5
FEET. ATLANTIC HIGH PRESSURE WILL REMAIN CENTERED EAST AND NORTH
OF THE AREA THROUGH MONDAY...WITH EAST WINDS ON FRIDAY...VEERING
TO SOUTHEAST SATURDAY THROUGH MONDAY.
LATER MONDAY THROUGH WEDNESDAY...THE FORECAST BECOMES HIGHLY
DEPENDENT ON THE EVENTUAL TRACK AND INTENSITY OF ERIKA. THE
LATEST NHC FORECAST HAS ERIKA APPROACHING THE WATERS LATER
TUESDAY. HAVE STARTED TO TREND WINDS AND SEAS UP BY MONDAY NIGHT
AND TUESDAY...BUT THERE IS A LOT OF UNCERTAINTY WITH THIS
FORECAST. FOR NOW...HAVE CAPED WINDS AT 30 KTS OR LESS TUESDAY AND
WEDNESDAY...WITH SEAS 10-15 FEET...MAINLY OFFSHORE.
PLEASE STAY TUNED TO THE LATEST FORECASTS FROM THE NATIONAL
HURRICANE CENTER AND OUR OFFICE CONCERNING ERIKA.
&&
.TIDES/COASTAL FLOODING...
THIS EVENING...CURRENT TIDE TRENDS SUGGEST TIDE LEVELS COULD PEAK
NEAR OR JUST ABOVE 7.0 FT MLLW IN THE CHARLESTON HARBOR. WITH THE
FAIRLY LIGHT WIND REGIME IN PLACE...IT IS POSSIBLE TIDES MAY FALL
JUST SHORT AS GUIDANCE TENDS TO RUN A BIT TOO HIGH THIS FAR OUT IN
THIS KIND OF REGIME. HOWEVER...A COASTAL FLOOD ADVISORY COULD
STILL BE NEEDED FOR PARTS OF THE LOWER SOUTH CAROLINA COAST LATER
TODAY. TRENDS SUGGEST TIDES WILL REMAIN BELOW ADVISORY CRITERIA
FORT PULASKI AND THE GEORGIA COAST.
FRIDAY THROUGH SUNDAY...ASTRONOMICAL TIDES WILL BE HIGH FRIDAY
THROUGH MID NEXT WEEK. EVEN WITHOUT ANY EFFECTS FROM
ERIKA...EXTRA- TROPICAL SURGE GUIDANCE SHOWS TIDES REACHING MINOR
COASTAL FLOOD LEVELS DURING THE MAJOR HIGH TIDES FOR FRIDAY AND
SATURDAY. EASTERLY LOW LEVEL FLOW FRIDAY AND SATURDAY WILL HELP TO
INCREASE TIDE LEVELS. WINDS BECOME MORE SOUTHEAST BY
SUNDAY...WHICH MAY NOT BE QUITE AS CONDUCIVE FOR PUSHING TIDE
LEVELS HIGHER...BUT WILL CONTINUE MONITORING THE POTENTIAL FOR
MINOR COASTAL FLOODING.
MONDAY THROUGH WEDNESDAY...ASTRONOMICAL TIDE LEVELS WILL REMAIN MUCH
HIGHER THAN NORMAL...AND IF THE LATEST FORECAST FROM NHC FOR ERIKA
HOLDS...WE WILL HAVE THE POTENTIAL FOR MORE SIGNIFICANT RISES IN THE
TIDES ALONG WITH SOME COASTAL FLOODING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/RFM
...PRELIMINARY AREA FORECAST DISCUSSION...
.SYNOPSIS...
A WEAK COLD FRONT AND ASSOCIATED AREA OF LOW PRESSURE WILL STALL AND
DISSIPATE ALONG THE SOUTHEAST COAST THROUGH THURSDAY. HIGH PRESSURE
WILL SETTLE IN NORTH OF THE REGION INTO FRIDAY BEFORE MOVING OFF THE
EAST COAST THIS WEEKEND. ANOTHER AREA OF HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIANS INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
THROUGH SUNRISE...AN IMPRESSIVE BAND OF STRONG TSTMS HAS DEVELOPED
ALONG AND JUST OFF THE SOUTHERN SOUTH CAROLINA COAST EARLY THIS
MORNING. NONE OF THE HIGHER RESOLUTION MODELS PICKED UP ON THIS
CONVECTION. EXPECT ACTIVITY TO GRADUALLY WIND DOWN AS SUNRISE
APPROACHES AND THE ATMOSPHERE OVER THE COASTAL WATERS BECOMES
INCREASINGLY OVERTURNED. THERE WILL BE A RISK FOR HEAVY RAIN
THROUGH SUNRISE...ESPECIALLY ALONG THE COLLETON AND CHARLESTON
COUNTY COASTS...ALONG WITH A RISK FOR FLOODING. FARTHER
INLAND...WATCHING FOR POSSIBLE LOW STRATUS AND FOG OOZING IN FROM
THE EASTERN MIDLANDS. NAM12 1000 HPA CONDENSATION PRESSURE
DEFICITS SHOW AREAS FROM WALTERBORO TO MONCKS CORNER HAVING THE
BEST CHANCES FOR LOW STRATUS AND POSSIBLY SOME REDUCTIONS IN
VISIBILITIES...BUT ANY FOG THAT DOES FORM SHOULD REMAIN FAIRLY
LIGHT GIVEN THE EXTENSIVE MID/HIGH CLOUD CANOPIES THAT ARE IN
PLACE.
TODAY...THE STATIONARY FRONT HAS BUCKLED BACK INLAND AWAY FROM THE
COAST EARLY THIS MORNING IN RESPONSE TO WEAK LOW PRESSURE
RETROGRADING INTO INTERIOR SOUTHEAST GEORGIA. MODELS SHOW THE
STATIONARY FRONT ESSENTIALLY BISECTING SOUTHEAST SOUTHEAST SOUTH
CAROLINA AND SOUTHEAST GEORGIA TODAY AS THE WESTERN EDGE OF A
RIBBON OF HIGHER 850-700 HPA THETA-E AIR NUDGES WEST. THIS
COUPLED WITH UPPER DIFLUENCE INDUCED BY THE RIGHT ENTRANCE REGION
OF A SUBTROPICAL JET STREAK POSITIONED OVER THE CAROLINA PIEDMONT
WILL SUPPORT SCATTERED SHOWERS/TSTMS LATER THIS MORNING AND
CONTINUING INTO THE AFTERNOON HOURS. THE RAP AND NSSL-WRF APPEAR
TO HAVE THE BEST HANDLE ON THE EXPECTED EVOLUTION OF CONVECTION
TODAY...BUT THERE ARE DEFINITELY SOME TEMPORAL AND SPATIAL
DIFFERENCES NOTED. WILL GO WITH A 30-50 POP REGIME FOR TODAY WITH
THE HIGHEST GRIDDED POPS PLACED ROUGHLY ALONG AND SOUTH OF A NORTH
CHARLESTON-HENDERSONVILLE-SPRINGFIELD-GLENNVILLE LINE. THIS
INCLUDES BOTH THE CHARLESTON AND SAVANNAH METRO AREAS. INITIALLY
THE AIRMASS WEST OF THE FRONT WILL LIKELY BE TOO DRY TO SUPPORT
DEEP CONVECTION...BUT THIS WILL CHANGE AS THE AFTERNOON PROGRESSES
AS MID-LEVEL THETA-E INCREASES. WILL CAP POPS AT 20-30 PERCENT
WELL INLAND FOR NOW. HIGHS WILL RANGE FROM THE UPPER 80S TO LOWER
90S INLAND WITH COOLER CONDITIONS AT THE BEACHES. THE PRIMARY
HAZARD FOR TODAY LOOKS TO BE LOCALLY HEAVY RAINFALL WITH A FEW
STRONG TSTMS BEING POSSIBLE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
TONIGHT...CONVECTION IS EXPECTED TO DIMINISH SLOWLY THIS
EVENING WITH ADDITIONAL SHOWERS/TSTMS DEVELOPING OVER THE COASTAL
WATERS IN RESPONSE TO LOW-LEVEL CONVERGENCE SHIFTING BACK TO THE
WESTERN WALL OF THE GULF STREAM. WILL NEED TO KEEP 20-40 PERCENT
POPS FOR MUCH OF THE NIGHT...HIGHEST AT THE COAST...AS THE LOW-
LEVEL FLOW REGIME WILL FAVOR SOME OF THIS ACTIVITY MAKING IT
INLAND. LOWS WILL RANGE FROM THE LOWER 70S INLAND WITH UPPER
70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON.
FRIDAY INTO SUNDAY...TO BE ISSUED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
TO BE ISSUED.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
THERE LOOKS TO BE TOO MUCH CLOUD COVER TO SUPPORT FOG AT EITHER
TERMINAL AND IT HAS BEEN REMOVED FOR THE 06Z TAF CYCLE. COULD SEE
SOME STRATUS WORK ITS WAY INTO KCHS PRIOR TO SUNRISE...BUT THE
BULK SHOULD REMAIN NORTH AND NORTHWEST OF THE TERMINAL. TSTM
ACTIVITY EAST OF KSAV WILL REMAIN EAST OF THE TERMINAL...BUT MAY
MAKE A RUN AT KCHS AFTER 09Z. WILL GO WITH VCTS FOR NOW THERE
FROM 09-12Z WITH BRIEF CIGS DROPPING TO BKN015. EXPECT VFR
OTHERWISE. SCATTERED SHOWERS/TSTMS WILL AFFECT THE REGION TODAY AS
A STATIONARY FRONT REMAINS INLAND FROM THE COAST. THERE ARE LARGE
DISCREPANCIES OF WHEN THE HIGHEST CHANCES FOR IMPACTS WILL OCCUR
AT EITHER TERMINAL. WILL THEREFORE LEAVE MENTION OF TSRA OUT OF
BOTH TERMINALS AFTER 12Z UNTIL A MORE DEFINITIVE TIMEFRAME CAN BE
ESTABLISHED.
EXTENDED AVIATION OUTLOOK...TO BE ISSUED.
&&
.MARINE...
TODAY...LIGHT WINDS WILL BECOME SOUTHEAST TODAY AS THE STATIONARY
FRONT MEANDERS FARTHER INLAND AND THE SEA BREEZE CIRCULATION TAKES
HOLD. SPEEDS LOOK TO MAX OUT AT 10-15 KT WITH SEAS 1-3 FT. TSTMS
COULD POSE A RISK FOR MARINERS WITH WIND GUSTS IN EXCESS OF 35
KT...CLOUD TO WATER LIGHTNING AND VSBYS LESS THAN 1 NM IN HEAVY
RAIN.
TONIGHT...SOUTHEAST WINDS WILL PREVAIL WITH WINDS GENERALLY 10-15
KT WITH SEAS 1-3 FT. TSTMS COULD POSE A RISK FOR MARINERS WITH
WIND GUSTS IN EXCESS OF 35 KT...CLOUD TO WATER LIGHTNING AND
VSBYS LESS THAN 1 NM IN HEAVY RAIN.
FRIDAY THROUGH TUESDAY NIGHT...TO BE ISSUED.
&&
.TIDES/COASTAL FLOODING...
THIS EVENING...CURRENT TIDE TRENDS SUGGEST TIDE LEVELS COULD PEAK
NEAR OR JUST ABOVE 7.0 FT MLLW IN THE CHARLESTON HARBOR. WITH THE
FAIRLY LIGHT WIND REGIME IN PLACE...IT IS POSSIBLE TIDES MAY FALL
JUST SHORT AS GUIDANCE TENDS TO RUN A BIT TOO HIGH THIS FAR OUT IN
THIS KIND OF REGIME. HOWEVER...A COASTAL FLOOD ADVISORY COULD
STILL BE NEEDED FOR PARTS OF THE LOWER SOUTH CAROLINA COAST LATER
TODAY. TRENDS SUGGEST TIDES WILL REMAIN BELOW ADVISORY CRITERIA
FORT PULASKI AND THE GEORGIA COAST.
FRIDAY INTO EARLY NEXT WEEK...TO BE ISSUED.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1006 PM CDT FRI AUG 28 2015
.UPDATE...626 PM CDT
HAVE ADJUSTED POPS DOWNWARD THROUGH THE MID EVENING HOURS TO
ACCOUNT FOR RADAR AND NEAR-TERM GUIDANCE TRENDS. LEADING EDGE OF
SHORTWAVE TROUGH AND VORTICITY MAXIMA WILL MOVE EAST FROM
WISCONSIN THIS EVENING...KEEPING BEST FORCING FOR PRECIP NORTH OF
THE STATE LINE. THUS...JUST HAVE GENERALLY ISOLATED
SHRA/INTERMITTENT SPRINKLE MENTION THROUGH MID EVENING IN FAR
NORTHERN ILLINOIS. VERY DRY AIR NOTED AROUND 800 MB ON A RECENT
AMDAR SOUNDING FROM MDW WILL MAKE IT TOUGH FOR ANY STEADY PRECIP
UNTIL DRY AIR GETS ERODED. UPPER TROUGH/SHORTWAVE AXIS AND
SHEARED VORT MAX ALONG TROUGH AXIS WILL SLOWLY PROGRESS FROM IA TO
NORTHERN IL LATE THIS EVENING AND OVERNIGHT...BRINGING GRADUALLY
INCREASING SHRA/RAIN COVERAGE FROM NORTHWEST TO SOUTHEAST...BUT
MANY AREAS ALONG AND EAST OF AN EVANSTON TO PONTIAC LINE COULD
VERY WELL REMAIN DRY THROUGH DAYBREAK. VERY LITTLE IF ANY
INSTABILITY OVER AREA THROUGH THE NIGHT AND POOR MIDLEVEL LAPSE
RATES SUPPORT KEEPING SLIGHT CHANCE TSRA AT BEST. THE REST OF THE
FORECAST LOOKS TO BE ON TRACK.
RC
&&
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
307 PM CDT
SATURDAY NIGHT THROUGH FRIDAY...
THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE
FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE
EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT
WITH PREVIOUS RUNS.
THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR
NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL
THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE
SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW
THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL
SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS
OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP
OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED
SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE
PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH
MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID
ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL
HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD
FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST
MAY CAUSE SOME DELAY IN THE MOISTURE RETURN.
THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE
MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE
LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD
PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE
HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL
EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING
ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN
IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A
LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT
INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA
AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED
OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS
WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD
COVER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* UNCERTAINTY IN WIND DIRECTION THROUGH MUCH OF THE PERIOD.
* CHANCES FOR RAIN LATE OVERNIGHT THROUGH MID MORNING...THEN
CHANCES FOR SHOWERS AND THUNDERSTORMS TOMORROW AFTERNOON.
BMD
//DISCUSSION...UPDATED 00Z...
WEAK LOW PRESSURE OVER IOWA THIS EVENING IS PROGGED TO LIFT ENE
AND FILL OVERNIGHT. SHOWERS ARE A FEW EMBEDDED THUNDERSTORMS ARE
ONGOING ACROSS WISCONSIN AND IOWA THIS EVENING AHEAD OF THE LOW
AND WILL GRADUALLY TRANSLATE EAST OVERNIGHT...REACHING RFD JUST
AFTER MIDNIGHT TONIGHT AND THEN THE CHICAGO TERMINALS EARLY ON
SATURDAY. A SECONDARY WAVE DIGGING ACROSS THE REGION TOMORROW IS
EXPECTED TO KICK OFF ADDITIONAL SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON. CONFIDENCE IN THE WIND
DIRECTION IS LOW WITH LARGE DIFFERENCES BETWEEN MODELS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM IN PRECIP TIMING EARLY SATURDAY...LOW-MEDIUM IN TSRA
TIMING/COVERAGE SATURDAY AFTERNOON.
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. EAST WIND.
MONDAY...VFR. SOUTHEAST WIND.
TUESDAY...VFR. SOUTH WIND.
WEDNESDAY...SLT CHC TSRA. PRIMARILY VFR. SOUTH WIND.
THURSDAY...VFR. SOUTH WIND.
BMD
&&
.MARINE...
310 PM CDT
HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE
THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN
IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY
AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A
TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS
TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE
OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST
WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
909 PM CDT FRI AUG 28 2015
.UPDATE...
ISSUED AT 903 PM CDT FRI AUG 28 2015
THE DRY AIR IN PLACE ACROSS CENTRAL IL HAS CAUSED THE LEADING PUSH
OF SHOWERS TO DISSIPATE BEFORE REACHING THE ILLINOIS RIVER. THAT
SHOULD CONTINUE TO BE THE CASE UNTIL AT LEAST 06Z/1AM. WE EXPECT
BETTER POTENTIAL FOR RAIN TOMORROW AS THE LOW AND COLD FRONT
REACH WESTERN IL. THE WEAKENING OF THE ENTIRE LOW PRESSURE SYSTEM
AS IT REACHES ILLINOIS WILL SUPPORT KEEPING THE POPS IN THE LOW
CHANCE CATEGORY. WILL DIMINISH THE SOUTHERN EXTENT OF CHANCE POPS
BETWEEN 06Z AND 12Z, BASED ON TRENDS THIS EVENING. A VEIL OF HIGH
CLOUDS WILL KEEP LOW TEMPS WARMER THAN LAST NIGHT, WITH READINGS
MAINLY IN THE MID 60S. UPDATES THIS EVENING WILL BE MAINLY IN THE
WEATHER/POP AREA, AS THE REMAINDER OF THE FORECAST IS GENERALLY ON
TRACK.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 243 PM CDT FRI AUG 28 2015
AFTERNOON SURFACE MAP SHOWING LOW PRESSURE CENTERED NEAR OMAHA, WITH
A WARM FRONT EXTENDING NORTHEAST ACROSS IOWA AND A COLD FRONT INTO
CENTRAL KANSAS. MAIN ACTIVITY OF SHOWERS AND THUNDERSTORMS HAS BEEN
CLOSER TO THE WARM FRONT AND TRACKING NORTH OF OUR FORECAST AREA. A
GENERAL EASTWARD PROGRESSION OF THE BOUNDARIES IS EXPECTED OVER THE
NEXT SEVERAL HOURS, WITH THE COLD FRONT APPROACHING THE
ILLINOIS/IOWA BORDER TOWARD 3-4 AM. FORECAST SOUNDINGS ARE RATHER
DRY BELOW 12,000 FEET FROM ABOUT PEORIA EAST AND SOUTH, AND AM
STARTING TO GET CONCERNED THAT THERE WILL BE LITTLE MORE THAN
ISOLATED SHOWERS BETWEEN I-55 AND THE ILLINOIS RIVER TONIGHT.
HOWEVER, THE HRRR AND ARW MODELS ARE A BIT MORE AGGRESSIVE WITH
SHOWERS MOVING INTO THIS AREA AFTER 3 AM, SO WILL MAINTAIN CHANCE
POP`S ACROSS THE ILLINOIS RIVER VALLEY MAINLY FROM LATE EVENING
THROUGH OVERNIGHT. INSTABILITY IS A LITTLE MORE SPARSE THOUGH, WITH
THE CURRENT THUNDER ACTIVITY MAINLY NEAR THE UPPER LEVEL DISTURBANCE
TRACKING ACROSS CENTRAL IOWA, AND HAVE TRIMMED BACK THE THUNDER
POTENTIAL TO MAINLY WEST OF THE RIVER. OTHERWISE, HAVE MAINLY GONE
DRY EAST OF I-55. MILDER CONDITIONS EXPECTED OVERNIGHT WITH CLOUD
COVER MUCH MORE EXTENSIVE AND A SOUTHERLY FLOW, WITH MOST AREAS
DIPPING INTO THE MID 60S.
.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 243 PM CDT FRI AUG 28 2015
LOW PRESSURE AREA AND ASSOCIATED FRONT WEST OF THE AREA WILL
CONTINUE TO SLOWLY MOVE EAST AND INTO THE CWA DURING THE WEEKEND.
HOWEVER...VERY LITTLE SUPPORT FOR THIS SYSTEM AS IT MOVES EAST SO
ALL MODELS HAVE THIS SYSTEM WEAKENING AS IT MOVES INTO THE AREA.
THEREFORE...WILL ONLY HAVE CHANCE POPS FOR SAT MORNING WEST OF I-55
AND THEN MOVE POPS EAST DURING THE AFTERNOON BUT REMAINING MAINLY
NORTH OF I-70 AS FRONT CONTINUES TO WEAKEN AND BECOME SOMEWHAT
PARALLEL TO THE FLOW AND VERY LACKING ON CONVERGENCE/SUPPORT. CHANCE
POPS FOR SAT NIGHT WILL CONTINUE AS THE UPPER LEVEL WAVE SHIFTS EAST
ACROSS THE AREA. PCPN WILL BE MAINLY SHOWERS AND ISOLATED
THUNDERSTORMS...DUE TO LACK OF FORCING AND INSTABILITY. BY
SUNDAY...THE WAVE SHOULD BE VERY WEAK AND EAST OF THE CWA...SO WILL
ONLY HAVE SLIGHT CHANCE POPS. FOR REMAINDER OF THE WEEKEND AND INTO
THE BEGINNING OF NEXT WEEK...DRY CONDITIONS CAN BE EXPECTED AS HIGH
PRESSURE BEGINS TO BUILD IN THE WEST AND PUSH INTO THE NORTHERN PART
OF THE AREA.
BEGINNING TUE AND THROUGH MOST OF THE WEEK...A COUPLE OF MODELS
BRING REMNANTS OF TS ERIKA INTO THE AREA. HOWEVER...THIS IS
DEPENDENT ON WHERE THE TS GOES. AND IT IS FAR ENOUGH AWAY IN TIME
THAT WILL JUST KEEP CLOSE TO WHAT THE CRINT HAS...AND THAT IS JUST
SLIGHT CHANCE POPS IN SOME AREAS FOR WED THROUGH THUR. SLIGHT CHANCE
POPS WILL BE IN THE GRIDS BUT NOT MENTIONED IN THE WORDED FORECAST.
TEMPS THROUGH THE WEEKEND WILL BE TEMPERED DUE TO CLOUD COVER AND
SCATTERED PCPN...BUT STILL EXPECTING THEM TO RISE INTO THE 80S FOR
THE WEEKEND. BY NEXT WEEK...WITH UPPER LEVEL RIDGING BUILDING INTO
THE AREA AND DEWPOINTS BEING DRIER...EXPECTING TEMPS TO RISE INTO
THE UPPER 80S TO AROUND 90 FOR THE ENTIRE WEEK. THIS WILL BE MUCH
ABOVE NORMAL FOR THE BEGINNING OF SEPT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 700 PM CDT FRI AUG 28 2015
LOW PRESSURE CENTERED IN WESTERN IOWA IS PROJECTED TO DRIFT EAST
AS IT GRADUALLY DISSIPATES NEAR WESTERN ILLINOIS SATURDAY
AFTERNOON/EVE. SHOWERS ARE DRIFTING INTO A RELATIVELY DRY AIRMASS,
AS CONFIRMED BY THE ILX 00Z SOUNDING. SPOTTY RAIN WILL EVENTUALLY
MOVE ACROSS CENTRAL ILLINOIS, AHEAD OF THE LOW. THE CHANCES ONLY
WARRANTED A VCSH AND VFR CLOUD COVER, BASED ON FORECAST SOUNDINGS
FROM HRRR AND RAP/NAM OUTPUT. WE STARTED VCSH AT PIA THE SOONEST,
AT 03Z, WHILE DELAYING AT BMI UNTIL 12Z AND THE SOUTHERN TAF SITES
AFTER 18Z. WINDS ARE EXPECTED TO REMAIN SOUTH THROUGH AT LEAST
18Z, THEN BEGIN TO SHIFT TO THE SOUTHWEST AS THE LOW AND COLD
FRONT APPROACH WESTERN ILLINOIS. PREVAILING WIND SPEEDS SHOULD
REMAIN 10KT OR LESS THROUGH TOMORROW AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
703 PM CDT FRI AUG 28 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 243 PM CDT FRI AUG 28 2015
AFTERNOON SURFACE MAP SHOWING LOW PRESSURE CENTERED NEAR OMAHA, WITH
A WARM FRONT EXTENDING NORTHEAST ACROSS IOWA AND A COLD FRONT INTO
CENTRAL KANSAS. MAIN ACTIVITY OF SHOWERS AND THUNDERSTORMS HAS BEEN
CLOSER TO THE WARM FRONT AND TRACKING NORTH OF OUR FORECAST AREA. A
GENERAL EASTWARD PROGRESSION OF THE BOUNDARIES IS EXPECTED OVER THE
NEXT SEVERAL HOURS, WITH THE COLD FRONT APPROACHING THE
ILLINOIS/IOWA BORDER TOWARD 3-4 AM. FORECAST SOUNDINGS ARE RATHER
DRY BELOW 12,000 FEET FROM ABOUT PEORIA EAST AND SOUTH, AND AM
STARTING TO GET CONCERNED THAT THERE WILL BE LITTLE MORE THAN
ISOLATED SHOWERS BETWEEN I-55 AND THE ILLINOIS RIVER TONIGHT.
HOWEVER, THE HRRR AND ARW MODELS ARE A BIT MORE AGGRESSIVE WITH
SHOWERS MOVING INTO THIS AREA AFTER 3 AM, SO WILL MAINTAIN CHANCE
POP`S ACROSS THE ILLINOIS RIVER VALLEY MAINLY FROM LATE EVENING
THROUGH OVERNIGHT. INSTABILITY IS A LITTLE MORE SPARSE THOUGH, WITH
THE CURRENT THUNDER ACTIVITY MAINLY NEAR THE UPPER LEVEL DISTURBANCE
TRACKING ACROSS CENTRAL IOWA, AND HAVE TRIMMED BACK THE THUNDER
POTENTIAL TO MAINLY WEST OF THE RIVER. OTHERWISE, HAVE MAINLY GONE
DRY EAST OF I-55. MILDER CONDITIONS EXPECTED OVERNIGHT WITH CLOUD
COVER MUCH MORE EXTENSIVE AND A SOUTHERLY FLOW, WITH MOST AREAS
DIPPING INTO THE MID 60S.
.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 243 PM CDT FRI AUG 28 2015
LOW PRESSURE AREA AND ASSOCIATED FRONT WEST OF THE AREA WILL
CONTINUE TO SLOWLY MOVE EAST AND INTO THE CWA DURING THE WEEKEND.
HOWEVER...VERY LITTLE SUPPORT FOR THIS SYSTEM AS IT MOVES EAST SO
ALL MODELS HAVE THIS SYSTEM WEAKENING AS IT MOVES INTO THE AREA.
THEREFORE...WILL ONLY HAVE CHANCE POPS FOR SAT MORNING WEST OF I-55
AND THEN MOVE POPS EAST DURING THE AFTERNOON BUT REMAINING MAINLY
NORTH OF I-70 AS FRONT CONTINUES TO WEAKEN AND BECOME SOMEWHAT
PARALLEL TO THE FLOW AND VERY LACKING ON CONVERGENCE/SUPPORT. CHANCE
POPS FOR SAT NIGHT WILL CONTINUE AS THE UPPER LEVEL WAVE SHIFTS EAST
ACROSS THE AREA. PCPN WILL BE MAINLY SHOWERS AND ISOLATED
THUNDERSTORMS...DUE TO LACK OF FORCING AND INSTABILITY. BY
SUNDAY...THE WAVE SHOULD BE VERY WEAK AND EAST OF THE CWA...SO WILL
ONLY HAVE SLIGHT CHANCE POPS. FOR REMAINDER OF THE WEEKEND AND INTO
THE BEGINNING OF NEXT WEEK...DRY CONDITIONS CAN BE EXPECTED AS HIGH
PRESSURE BEGINS TO BUILD IN THE WEST AND PUSH INTO THE NORTHERN PART
OF THE AREA.
BEGINNING TUE AND THROUGH MOST OF THE WEEK...A COUPLE OF MODELS
BRING REMNANTS OF TS ERIKA INTO THE AREA. HOWEVER...THIS IS
DEPENDENT ON WHERE THE TS GOES. AND IT IS FAR ENOUGH AWAY IN TIME
THAT WILL JUST KEEP CLOSE TO WHAT THE CRINT HAS...AND THAT IS JUST
SLIGHT CHANCE POPS IN SOME AREAS FOR WED THROUGH THUR. SLIGHT CHANCE
POPS WILL BE IN THE GRIDS BUT NOT MENTIONED IN THE WORDED FORECAST.
TEMPS THROUGH THE WEEKEND WILL BE TEMPERED DUE TO CLOUD COVER AND
SCATTERED PCPN...BUT STILL EXPECTING THEM TO RISE INTO THE 80S FOR
THE WEEKEND. BY NEXT WEEK...WITH UPPER LEVEL RIDGING BUILDING INTO
THE AREA AND DEWPOINTS BEING DRIER...EXPECTING TEMPS TO RISE INTO
THE UPPER 80S TO AROUND 90 FOR THE ENTIRE WEEK. THIS WILL BE MUCH
ABOVE NORMAL FOR THE BEGINNING OF SEPT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 700 PM CDT FRI AUG 28 2015
LOW PRESSURE CENTERED IN WESTERN IOWA IS PROJECTED TO DRIFT EAST
AS IT GRADUALLY DISSIPATES NEAR WESTERN ILLINOIS SATURDAY
AFTERNOON/EVE. SHOWERS ARE DRIFTING INTO A RELATIVELY DRY AIRMASS,
AS CONFIRMED BY THE ILX 00Z SOUNDING. SPOTTY RAIN WILL EVENTUALLY
MOVE ACROSS CENTRAL ILLINOIS, AHEAD OF THE LOW. THE CHANCES ONLY
WARRANTED A VCSH AND VFR CLOUD COVER, BASED ON FORECAST SOUNDINGS
FROM HRRR AND RAP/NAM OUTPUT. WE STARTED VCSH AT PIA THE SOONEST,
AT 03Z, WHILE DELAYING AT BMI UNTIL 12Z AND THE SOUTHERN TAF SITES
AFTER 18Z. WINDS ARE EXPECTED TO REMAIN SOUTH THROUGH AT LEAST
18Z, THEN BEGIN TO SHIFT TO THE SOUTHWEST AS THE LOW AND COLD
FRONT APPROACH WESTERN ILLINOIS. PREVAILING WIND SPEEDS SHOULD
REMAIN 10KT OR LESS THROUGH TOMORROW AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
632 PM CDT FRI AUG 28 2015
.UPDATE...
626 PM CDT
HAVE ADJUSTED POPS DOWNWARD THROUGH THE MID EVENING HOURS TO
ACCOUNT FOR RADAR AND NEAR-TERM GUIDANCE TRENDS. LEADING EDGE OF
SHORTWAVE TROUGH AND VORTICITY MAXIMA WILL MOVE EAST FROM
WISCONSIN THIS EVENING...KEEPING BEST FORCING FOR PRECIP NORTH OF
THE STATE LINE. THUS...JUST HAVE GENERALLY ISOLATED
SHRA/INTERMITTENT SPRINKLE MENTION THROUGH MID EVENING IN FAR
NORTHERN ILLINOIS. VERY DRY AIR NOTED AROUND 800 MB ON A RECENT
AMDAR SOUNDING FROM MDW WILL MAKE IT TOUGH FOR ANY STEADY PRECIP
UNTIL DRY AIR GETS ERODED. UPPER TROUGH/SHORTWAVE AXIS AND
SHEARED VORT MAX ALONG TROUGH AXIS WILL SLOWLY PROGRESS FROM IA TO
NORTHERN IL LATE THIS EVENING AND OVERNIGHT...BRINGING GRADUALLY
INCREASING SHRA/RAIN COVERAGE FROM NORTHWEST TO SOUTHEAST...BUT
MANY AREAS ALONG AND EAST OF AN EVANSTON TO PONTIAC LINE COULD
VERY WELL REMAIN DRY THROUGH DAYBREAK. VERY LITTLE IF ANY
INSTABILITY OVER AREA THROUGH THE NIGHT AND POOR MIDLEVEL LAPSE
RATES SUPPORT KEEPING SLIGHT CHANCE TSRA AT BEST. THE REST OF THE
FORECAST LOOKS TO BE ON TRACK.
RC
&&
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
307 PM CDT
SATURDAY NIGHT THROUGH FRIDAY...
THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE
FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE
EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT
WITH PREVIOUS RUNS.
THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR
NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL
THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE
SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW
THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL
SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS
OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP
OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED
SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE
PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH
MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID
ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL
HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD
FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST
MAY CAUSE SOME DELAY IN THE MOISTURE RETURN.
THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE
MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE
LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD
PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE
HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL
EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING
ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN
IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A
LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT
INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA
AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED
OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS
WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD
COVER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* UNCERTAINTY IN WIND DIRECTION THROUGH MUCH OF THE DAY TOMORROW.
* CHANCES FOR RAIN LATE OVERNIGHT THROUGH MID MORNING...THEN
CHANCES FOR SHOWERS AND THUNDERSTORMS TOMORROW AFTERNOON.
BMD
//DISCUSSION...UPDATED 00Z...
WEAK LOW PRESSURE OVER IOWA THIS EVENING IS PROGGED TO LIFT ENE
AND FILL OVERNIGHT. SHOWERS ARE A FEW EMBEDDED THUNDERSTORMS ARE
ONGOING ACROSS WISCONSIN AND IOWA THIS EVENING AHEAD OF THE LOW
AND WILL GRADUALLY TRANSLATE EAST OVERNIGHT...REACHING RFD JUST
AFTER MIDNIGHT TONIGHT AND THEN THE CHICAGO TERMINALS EARLY ON
SATURDAY. A SECONDARY WAVE DIGGING ACROSS THE REGION TOMORROW IS
EXPECTED TO KICK OFF ADDITIONAL SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON. CONFIDENCE IN THE WIND
DIRECTION IS LOW WITH LARGE DIFFERENCES BETWEEN MODELS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM IN PRECIP TIMING EARLY SATURDAY...LOW-MEDIUM IN TSRA
TIMING/COVERAGE SATURDAY AFTERNOON.
* LOW CONFIDENCE IN WIND DIRECTION SATURDAY.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. EAST WIND.
MONDAY...VFR. SOUTHEAST WIND.
TUESDAY...VFR. SOUTH WIND.
WEDNESDAY...SLT CHC TSRA. PRIMARILY VFR. SOUTH WIND.
THURSDAY...VFR. SOUTH WIND.
BMD
&&
.MARINE...
310 PM CDT
HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE
THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN
IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY
AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A
TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS
TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE
OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST
WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
626 PM CDT FRI AUG 28 2015
.UPDATE...
626 PM CDT
HAVE ADJUSTED POPS DOWNWARD THROUGH THE MID EVENING HOURS TO
ACCOUNT FOR RADAR AND NEAR-TERM GUIDANCE TRENDS. LEADING EDGE OF
SHORTWAVE TROUGH AND VORTICITY MAXIMA WILL MOVE EAST FROM
WISCONSIN THIS EVENING...KEEPING BEST FORCING FOR PRECIP NORTH OF
THE STATE LINE. THUS...JUST HAVE GENERALLY ISOLATED
SHRA/INTERMITTENT SPRINKLE MENTION THROUGH MID EVENING IN FAR
NORTHERN ILLINOIS. VERY DRY AIR NOTED AROUND 800 MB ON A RECENT
AMDAR SOUNDING FROM MDW WILL MAKE IT TOUGH FOR ANY STEADY PRECIP
UNTIL DRY AIR GETS ERODED. UPPER TROUGH/SHORTWAVE AXIS AND
SHEARED VORT MAX ALONG TROUGH AXIS WILL SLOWLY PROGRESS FROM IA TO
NORTHERN IL LATE THIS EVENING AND OVERNIGHT...BRINGING GRADUALLY
INCREASING SHRA/RAIN COVERAGE FROM NORTHWEST TO SOUTHEAST...BUT
MANY AREAS ALONG AND EAST OF AN EVANSTON TO PONTIAC LINE COULD
VERY WELL REMAIN DRY THROUGH DAYBREAK. VERY LITTLE IF ANY
INSTABILITY OVER AREA THROUGH THE NIGHT AND POOR MIDLEVEL LAPSE
RATES SUPPORT KEEPING SLIGHT CHANCE TSRA AT BEST. THE REST OF THE
FORECAST LOOKS TO BE ON TRACK.
RC
&&
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
307 PM CDT
SATURDAY NIGHT THROUGH FRIDAY...
THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE
FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE
EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT
WITH PREVIOUS RUNS.
THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR
NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL
THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE
SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW
THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL
SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS
OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP
OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED
SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE
PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH
MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID
ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL
HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD
FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST
MAY CAUSE SOME DELAY IN THE MOISTURE RETURN.
THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE
MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE
LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD
PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE
HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL
EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING
ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN
IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A
LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT
INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA
AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED
OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS
WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD
COVER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* CHANCE OF SHRA/SLIGHT CHANCE OF TS TONIGHT INTO SAT MORNING.
SLIGHTLY BETTER CHANCE OF THUNDER SATURDAY AFTERNOON.
KJB/BMD
//DISCUSSION...UPDATED 18Z...
AN ATMOSPHERIC DISTURBANCE...CURRENTLY DRIVING AN AREA OF SHOWERS
AND EMBEDDED STORMS OVER IOWA...WILL GRADUALLY SHIFT EASTWARD
TONIGHT. HOWEVER...IT APPEARS THE MAIN FOCUS FOR SHOWERS AND ANY
STORMS MAY LARGELY REMAIN NORTH OF THE EASTERN TERMINALS...ACROSS
FAR NORTHERN ILLINOIS AND INTO WISCONSIN. BETTER CHANCES OF MORE
SUBSTANTIAL SHOWERS LOOKS TO ENTER THE PICTURE AFTER DAYBREAK
SATURDAY...AND CONTINUING AT TIMES INTO THE AFTERNOON. IT APPEARS
THE THUNDER THREAT WILL BE LOW WITH MUCH OF THIS ACTIVITY.
HOWEVER...THERE WILL BE A SLIGHT BETTER CHANCE OF THUNDER SUNDAY
AFTERNOON AS A FRONTAL ZONE SAGS SOUTHEASTWARD OVER THE AREA.
GIVEN THIS...I HAVE OPTED TO ADD A PROB30 FOR A PERIOD OF THUNDER
LATER SATURDAY AFTERNOON AT THE END OF THE 30 HOUR ORD TAF.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM WITH PRECIP CHANCES/TIMING...ESPECIALLY SATURDAY
MORNING/EARLY AFTERNOON.
* LOW WITH THREAT OF THUNDER DURING THE PERIOD.
* HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS.
KJB/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
SUNDAY...VFR. NORTHEAST WINDS.
MONDAY THROUGH THURSDAY...VFR. SOUTHERLY WINDS...POSSIBLE
AFTERNOON WIND SHIFTS TO EASTERLY WITH LAKE BREEZES EACH
AFTERNOON.
IZZI
&&
.MARINE...
310 PM CDT
HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE
THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN
IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY
AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A
TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS
TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE
OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST
WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
330 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY)
ISSUED AT 326 AM CDT THU AUG 27 2015
EARLY MORNING SURFACE MAP INDICATES HIGH PRESSURE OVER NORTH CENTRAL
ILLINOIS RESULTING IN A MOSTLY CLEAR SKY AND RATHER COOL
TEMPERATURES. IDEAL RADIATIONAL CONDITIONS UNDERNEATH THE LARGE FAIR
WEATHER SYSTEM THIS MORNING WITH THE MERCURY ALREADY DOWN TO 48
DEGREES HERE AT THE OFFICE IN LINCOLN WITH A FEW OTHER LOCATIONS
APPROACHING 50 DEGREES. TEMP-DEW POINT SPREADS DECREASING AS WELL
SO SOME PATCHY FOG WILL BE POSSIBLE EARLY THIS MORNING WITH ANY
FOG DISSIPATING QUICKLY AS TEMPERATURES WARM RAPIDLY THRU THE
MORNING HOURS. FORECAST SOUNDINGS SUGGEST SOME CLOUDS DEVELOPING
AGAIN LATE THIS MORNING INTO THIS AFTERNOON, ESPECIALLY OVER THE
EASTERN HALF OF THE FORECAST AREA. HOWEVER, WE ARE NOT EXPECTING AS
MUCH CLOUDINESS AS WE SAW YESTERDAY WHICH SHOULD KEEP TEMPERATURES
MORE UNIFORM OVER CENTRAL ILLINOIS WITH HIGHS RANGING FROM THE
MID 70S FAR EAST TO AROUND 80 ACROSS THE REMAINDER OF THE FORECAST
AREA.
&&
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 326 AM CDT THU AUG 27 2015
TEMPERATURES CLOSE TO CLIMATOLOGICAL NORMS TONIGHT AND TOMORROW AS
STORM SYSTEM TAKES SHAPE AND MOVES INTO THE REGION. WAVE IS
CURRENTLY OVER THE NORTHERN ROCKIES AND IS SLIDING THROUGH THE
PLAINS AND INTO THE MIDWEST TO BRING INCREASING CHANCES FOR PRECIP
FOR FRI NIGHT AND SATURDAY. ALTHOUGH THE MODELS ARE DOING BETTER
WITH THE TIMING OF THE WAVE, THE SOUTHERN EXTENT OF THE BETTER
PRECIP COVERAGE IS STILL BEING CALLED INTO QUESTION. A DRY AIRMASS
OVERALL ON ILX SOUNDINGS IS PART OF THE PROBLEM. ALTHOUGH THE SFC
WINDS BECOME MORE SOUTHERLY THROUGH THE DAY ON FRIDAY, THE MOISTURE
ADVECTION IS LIMITED BY LIGHTER WINDS TO THE SOUTH. THE MODELS HAVE
BEEN TRENDING THE WAVE A LITTLE FURTHER NORTH IN THE LATEST RUNS AS
WELL. STILL CONCERNED THAT THE PRECIP WILL STILL BE MORE
INTERMITTENT THAN WIDESPREAD ALONG THE FRONTAL PASSAGE...WITH WEAKER
CONVERGENCE ALONG THE BOUNDARY. GFS AND NAM STARTING TO TREND THAT
WAY, LINGERING THE PRECIP INTO SAT NIGHT AND IN THE EAST FOR EARLY
SUNDAY MORNING.
WAVE MOVING THROUGH EFFECTIVELY SHIFTS THE NORTHWESTERLY FLOW TO A
MORE SOUTHWESTERLY FROM THE SOUTHERN PAC COAST INTO THE HUDSON BAY
REGION...AND RATHER WEAK FLOW ALOFT FOR MOST OF THE EASTERN HALF
OF THE COUNTRY AFTER THE WEEKEND. HOT TEMPS UNDER THE RIDGE IN THE
SOUTHWESTERN CONUS DIFFUSE INTO THE REGION WITH THE PATTERN SHIFT
AND TEMPS THROUGH THE MIDDLE OF NEXT WEEK SIGNIFICANTLY ABOVE
NORMALS WITH MAX TEMPS APPROACHING THE 90 MARK BEFORE MIDWEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1149 PM CDT WED AUG 26 2015
THE LATEST FEW RUNS OF THE HRRR HAVE INTRODUCED LOCALLY DENSE FOG
ACROSS EASTERN AREAS OF CENTRAL IL. BMI AND CMI APPEAR TO HAVE THE
BETTER POTENTIAL FOR DENSE FOG, WITH MVFR FOG FOR DEC, SPI AND
PIA. THE FOG POTENTIAL APPEARS REASONABLE DUE TO IDEAL RADIATIONAL
COOLING CONDITIONS, AND AFTERNOON MIN DEWPOINTS WITHIN A COUPLE
DEGREES OF FORECAST LOWS. WILL INTRODUCE TEMPO GROUPS FOR FOG IN
ALL TAFS FOR LATE TONIGHT.
AFTER THE FOG BURNS OFF, MODEL SOUNDINGS SHOW THAT SOME PATCHY
CUMULUS ARE EXPECTED IN THE EASTERN PORTIONS OF OUR FORECAST AREA,
CLOSER TO BMI AND CMI. NO MVFR CEILINGS ARE EXPECTED.
WINDS WILL REMAIN LIGHT AND VARIABLE FOR THE REST OF THE NIGHT AS
THE SURFACE RIDGE AXIS LINGERS FROM NE TO SW ACROSS ILLINOIS.
SOUTHEAST WINDS WILL DEVELOP THURSDAY MORNING AS THE RIDGE AXIS
MOVES EAST OF OUR COUNTIES. HOWEVER, WIND SPEEDS SHOULD PREVAIL AT
LESS THAN 1OKT THROUGH THE DAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1149 PM CDT WED AUG 26 2015
.UPDATE...
ISSUED AT 900 PM CDT WED AUG 26 2015
CLOUDS ASSOCIATED WITH THE UPPER TROUGH AND TO SOME EXTENT LAKE
MICHIGAN, HAVE SHIFTED E-NE OF OUR COUNTIES, LEAVING CLEAR SKIES
UNDER THE SURFACE RIDGE OF HIGH PRESSURE. LITTLE TO NO AIRMASS
CHANGES ARE EXPECTED OVERNIGHT AS WINDS BECOME LIGHT AND VARIABLE.
RADIATIONAL COOLING SHOULD ALLOW TEMPS TO DIP INTO THE LOW-MID 50S
IN MOST AREAS. TRIMMED A DEGREE OR SO FROM AREAS NORTHEAST OF THE
LAKE TO ALLOW FOR SOME 52 DEG READINGS, AND UPDATED THE SKY GRIDS
TO ACCOUNT FOR EARLIER CLEARING. OTHERWISE, THE FORECAST LOOKS ON
TRACK. UPDATED INFO IS ALREADY AVAILABLE.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 200 PM CDT WED AUG 26 2015
LARGE STRATOCUMULUS SHIELD THAT HAS PUSHED SOUTHWARD ACROSS THE
NORTHEAST QUARTER OF THE STATE WAS FINALLY STARTING TO SHOW SOME
CONTRACTION EARLY THIS AFTERNOON. HOWEVER...IT IS FLANKED ON MOST
SIDES BY DIURNAL DEVELOPMENT...SO NET RESULT CONTINUES TO BE QUITE A
BIT OF CLOUDS ESPECIALLY ACROSS THE EAST HALF OF THE CWA. THE 900 MB
PLOT OFF THE RAP MODEL CONTINUES TO DEPICT THE CLOUD SHIELD THE
BEST...AND SHOWS SOME CONTRACTION CONTINUING THIS AFTERNOON. MOST OF
THE DIURNAL CLOUDS SHOULD FADE WITH SUNSET. HOWEVER...SOME RESIDUAL
MOISTURE SHOULD LINGER FROM THE PERSISTENT CLOUDS...AND WILL GO WITH
PARTLY CLOUDY SKIES ACROSS THE NORTHEAST CORNER OF THE FORECAST AREA
NEAR DANVILLE AND CHAMPAIGN.
WITH HIGH PRESSURE OVERHEAD...ENOUGH CLEAR SKIES EXPECTED THAT MOST
AREAS SHOULD FALL INTO THE MID 50S OVERNIGHT. HOWEVER...SOME
ADJUSTMENTS MAY BE NEEDED ACROSS THE NORTHEAST IF THE CLOUDS DO NOT
CLEAR OUT FAST ENOUGH...AS HAS BEEN THE CASE THE LAST COUPLE NIGHTS.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT WED AUG 26 2015
LATEST MODEL SOLUTIONS IN REASONABLE AGREEMENT FOR ILLINOIS OVER
THE REST OF THE WEEK. MODELS DIFFER IN STRENGTH AND MOISTURE
AVAILABILITY OF SOUTHERN STREAM WAVE CURRENTLY OVER FOUR CORNERS
AREA AND EXPECTED TO RIDE OVER RIDGE INTO ILLINOIS THIS WEEKEND.
WATER VAPOR IMAGERY SHOWS WAVE OVER NORTHERN ARIZONA THIS MORNING
PUSHING NORTHWARD OVER STRONG ROCKIES RIDGE. MODEL SUITE CONSISTENT
ON BRINGING ENERGY UP OVER THE RIDGE AND INTO MIDWEST FRIDAY AND
SATURDAY. UNTIL THEN...DRY CONDITIONS AND A WARMING TREND IS
EXPECTED AS 850 TEMPS CLIMB 5-10 DEGREES C BETWEEN THIS MORNINGS
RAOB AND FRIDAY EVENING. INCREASING HIGH CLOUDS AHEAD OF THE WAVE
MAY INHIBIT WARMING A BIT FOR FRIDAY...BUT TEMPS SHOULD STILL MAKE
IT INTO THE 80S THROUGHOUT FORECAST AREA BY FRIDAY AFTERNOON.
WAVE APPROACHING FOR THE FIRST PART OF THE WEEKEND IS MOVING INTO A
RELATIVELY DRY BUT MOISTENING AIRMASS. IN ADDITION...DIGGING OF
NORTHERN STREAM ENERGY ALONG THE WEST COAST SHOULD SLOW PROGRESSION
OF SYSTEMS AND THEREFORE SLOW THE INCOMING WAVE. CHANCE OF STORMS
ARE EXPECTED IN THE NORTHWEST BY LATE AFTERNOON FRIDAY AND ACROSS
MUCH OF THE AREA FRIDAY NIGHT AND PARTICULARLY SATURDAY. MAIN MODEL
DIFFERENCES BEGIN TO SHOW UP TOWARD THE END OF THE WEEKEND. LATEST
AVAILABLE ECMWF RUNS HAVE BEEN CONSISTENT ON BEING STRONG ENOUGH
WITH THIS WAVE TO DEVELOP DECENT NVA IN ITS WAKE ON SUNDAY AND
SHUNTING MOISTURE EAST OF THE AREA. THIS LEADS TO A RELATIVELY DRY
BUT INCREASINGLY HOT FORECAST AS THE LONGWAVE RIDGE AXIS MOVES
ACROSS THE AREA. MEANWHILE...THE 06Z AND 12Z GFS TRENDING WEAKER
WITH THE WAVE AND FORECAST AN EVOLUTION TO JUST A GENERAL WEAKNESS
OVER THE AREA THROUGH EARLY NEXT WEEK. THIS EVOLUTION SUGGESTS AT
LEAST A SLIGHT CHANCE OF THUNDERSTORMS AND LOWER TEMPERATURES
WITH GENERALLY MORE CLOUD COVER. AM LEANING TOWARD A COMPROMISE
WITH A NOD TOWARD THE GFS WHICH SEEMS TO BE SUPPORTED BY THE CMC
AND GEFS MEAN. A QUICK LOOK AT 12Z ECMWF ALSO SUGGESTS IT MAY BE
SWINGING BACK TOWARD A WEAKER SOLUTION.
ANY CONVECTION THAT DEVELOPS THIS WEEKEND INTO NEXT WEEK SHOULD HAVE
LIMITED SEVERE POTENTIAL DUE TO LOW SHEAR IN THE RIDGE AND LIMITED
INSTABILITY GIVEN THE WARM 500 MB TEMPS CLIMBING ABOVE -10C. BIGGEST
THREAT MAY BE LOCALLY HEAVY RAINFALL DUE TO SLOW MOVEMENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1149 PM CDT WED AUG 26 2015
THE LATEST FEW RUNS OF THE HRRR HAVE INTRODUCED LOCALLY DENSE FOG
ACROSS EASTERN AREAS OF CENTRAL IL. BMI AND CMI APPEAR TO HAVE THE
BETTER POTENTIAL FOR DENSE FOG, WITH MVFR FOG FOR DEC, SPI AND
PIA. THE FOG POTENTIAL APPEARS REASONABLE DUE TO IDEAL RADIATIONAL
COOLING CONDITIONS, AND AFTERNOON MIN DEWPOINTS WITHIN A COUPLE
DEGREES OF FORECAST LOWS. WILL INTRODUCE TEMPO GROUPS FOR FOG IN
ALL TAFS FOR LATE TONIGHT.
AFTER THE FOG BURNS OFF, MODEL SOUNDINGS SHOW THAT SOME PATCHY
CUMULUS ARE EXPECTED IN THE EASTERN PORTIONS OF OUR FORECAST AREA,
CLOSER TO BMI AND CMI. NO MVFR CEILINGS ARE EXPECTED.
WINDS WILL REMAIN LIGHT AND VARIABLE FOR THE REST OF THE NIGHT AS
THE SURFACE RIDGE AXIS LINGERS FROM NE TO SW ACROSS ILLINOIS.
SOUTHEAST WINDS WILL DEVELOP THURSDAY MORNING AS THE RIDGE AXIS
MOVES EAST OF OUR COUNTIES. HOWEVER, WIND SPEEDS SHOULD PREVAIL AT
LESS THAN 1OKT THROUGH THE DAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...GEELHART
LONG TERM...BARKER
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 PM EDT FRI AUG 28 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 313 PM EDT FRI AUG 28 2015
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH TONIGHT. A
WEAK FRONTAL SYSTEM WILL SETTLE INTO THE OHIO VALLEY THIS WEEKEND.
HIGH PRESSURE WILL BUILD BACK INTO THE AREA FOR THE EARLY NEXT WEEK.
A FEW DISTURBANCES MAY MOVE THROUGH CENTRAL INDIANA THROUGH THE
MIDDLE TO END OF THE NEXT WORK WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 948 PM EDT FRI AUG 28 2015
UPPED CLOUDS A BIT IN THE WEST TONIGHT BASED ON LATEST TRENDS SEEN
ON SATELLITE. HRRR TRIES TO BRING IN A FEW SHOWERS LATE TONIGHT BUT
DO NOT BELIEVE THERE WILL BE ENOUGH FORCING TO GENERATE MUCH RAIN.
CANNOT RULE OUT A FEW SPRINKLES AS DYING SHOWERS MOVE IN LATE...BUT
NOT ENOUGH EXPECTED TO ADD THESE TO THE FORECAST.
TEMPERATURE FORECAST LOOKS GOOD.
PREVIOUS DISCUSSION FOLLOWS...
WILL KEEP THE FORECAST DRY FOR TONIGHT AS SURFACE HIGH PRESSURE
HOLDS ON. SHORT TERM MODELS AND LATEST TRENDS TO THE WEST INDICATE
THERE WILL BE A GRADUAL INCREASE OF MID AND HIGH LEVEL CLOUD COVER.
A MOS BLEND FOR LOWS LOOKS REASONABLE GIVEN THE EXPECTED CLOUD COVER
FOR LOW TEMPERATURES 60-65.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 313 PM EDT FRI AUG 28 2015
MODELS REMAIN INCONSISTENT WITH REGARD TO MOISTURE AMOUNTS AND TRACK
OF A WEAK FRONTAL SYSTEM...WHICH IS ASSOCIATED WITH AN UPPER TROUGH
AND EXPECTED TO MOVE THROUGH THIS WEEKEND. INSTABILITY IS NOT GREAT
BUT AT LEAST WARRANTS MENTION OF SCATTERED THUNDERSTORMS DURING THIS
WEEKEND. BEST CHANCES APPEAR TO BE SATURDAY EVENING WHEN THE FRONTAL
SYSTEM IS PROJECTED TO CROSS THE AREA. WEAK CHANCES WILL EXIST
SATURDAY AFTERNOON AND AGAIN ON SUNDAY INTO SUNDAY NIGHT. SINCE THE
MODELS HAVE YET TO COME TO A CONSENSUS SOLUTION AND REMAIN
INCONSISTENT...KEPT CHANCES BELOW THE "LIKELY" CATEGORY...FOR NOW.
PRECIP CHANCES WILL QUICKLY BEGIN TO DWINDLE BY EARLY MONDAY
MORNING AS A RIDGE OF HIGH PRESSURE QUICKLY REESTABLISHES ITS
HOLD OVER THE REGION. DRY CONDITIONS ARE GENERALLY EXPECTED TO
KICK OFF THE WORK WEEK. AND TEMPERATURES WILL HAVE SLOWLY
ACCLIMATED BACK TO SEASONAL NORMAL BY MONDAY. WELCOME BACK
SUMMER...
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 252 PM EDT FRI AUG 28 2015
BROAD UPPER RIDGING WILL BE ACROSS THE AREA DURING THE LONG TERM.
HOWEVER THE INFLUENCE OF MOISTURE FROM ERIKA NOW LOOKS LIKE IT COULD
COME INTO PLAY IN THE MIDWEST/OHIO VALLEY DURING THE WEEK. WITH
MODELS TRENDING TOWARD BRINGING SOME ENERGY AROUND THE UPPER RIDGE
AND BRING MOISTURE NORTH THOUGHT IT PRUDENT TO FOLLOW THAT TREND AND
INCLUDE SOME SLIGHT CHANCES FOR THUNDERSTORMS DURING THE DAY FROM
WEDNESDAY THROUGH FRIDAY. THE INITIALIZATION FOLLOWED THIS TREND AS
WELL AND JUST NEEDED SOME QUALITY CONTROL TWEAKS. TEMPERATURE-WISE
LOOKING AT HIGHS JUST ABOVE NORMAL IN THE MID TO UPPER 80S FROM THE
INITIALIZATION AND THESE LOOK GOOD. HIGHS IN THE 90S NOT OUT OF THE
QUESTION BUT SHOULD ONLY BE ATTAINABLE IF THE TROPICAL MOISTURE
DOESN/T MAKE IT THIS WAY.
&&
.AVIATION /DISCUSSION FOR 290300Z TAF UPDATE/...
ISSUED AT 1025 PM EDT FRI AUG 28 2015
ONLY MADE MINOR TWEAKS TO KIND TAF.
PREVIOUS DISCUSSION FOLLOWS...
VFR EXPECTED THROUGH THE PERIOD.
ANY LINGERING CUMULUS WILL DISSIPATE AFTER SUNSET LEAVING BEHIND
INCREASING MID AND HIGH CLOUDS DURING THE NIGHT. THESE CLOUDS
SHOULD HELP KEEP ANY FOG AT BAY.
A WEAK SYSTEM WILL MOVE IN ON SATURDAY AND WILL GENERATE SOME
SCATTERED CONVECTION IN THE AFTERNOON...WITH BEST CHANCES ARRIVING IN
THE EVENING AFTER 00Z. EVEN THEN ODDS WILL BE TOO LOW TO MENTION IN
TAFS.
LIGHT WINDS OVERNIGHT WILL BECOME SOUTHWEST ON SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF/50
SHORT TERM...SMF
LONG TERM....CP
AVIATION...50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
948 PM EDT FRI AUG 28 2015
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 313 PM EDT FRI AUG 28 2015
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH TONIGHT. A
WEAK FRONTAL SYSTEM WILL SETTLE INTO THE OHIO VALLEY THIS WEEKEND.
HIGH PRESSURE WILL BUILD BACK INTO THE AREA FOR THE EARLY NEXT WEEK.
A FEW DISTURBANCES MAY MOVE THROUGH CENTRAL INDIANA THROUGH THE
MIDDLE TO END OF THE NEXT WORK WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 948 PM EDT FRI AUG 28 2015
UPPED CLOUDS A BIT IN THE WEST TONIGHT BASED ON LATEST TRENDS SEEN
ON SATELLITE. HRRR TRIES TO BRING IN A FEW SHOWERS LATE TONIGHT BUT
DO NOT BELIEVE THERE WILL BE ENOUGH FORCING TO GENERATE MUCH RAIN.
CANNOT RULE OUT A FEW SPRINKLES AS DYING SHOWERS MOVE IN LATE...BUT
NOT ENOUGH EXPECTED TO ADD THESE TO THE FORECAST.
TEMPERATURE FORECAST LOOKS GOOD.
PREVIOUS DISCUSSION FOLLOWS...
WILL KEEP THE FORECAST DRY FOR TONIGHT AS SURFACE HIGH PRESSURE
HOLDS ON. SHORT TERM MODELS AND LATEST TRENDS TO THE WEST INDICATE
THERE WILL BE A GRADUAL INCREASE OF MID AND HIGH LEVEL CLOUD COVER.
A MOS BLEND FOR LOWS LOOKS REASONABLE GIVEN THE EXPECTED CLOUD COVER
FOR LOW TEMPERATURES 60-65.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 313 PM EDT FRI AUG 28 2015
MODELS REMAIN INCONSISTENT WITH REGARD TO MOISTURE AMOUNTS AND TRACK
OF A WEAK FRONTAL SYSTEM...WHICH IS ASSOCIATED WITH AN UPPER TROUGH
AND EXPECTED TO MOVE THROUGH THIS WEEKEND. INSTABILITY IS NOT GREAT
BUT AT LEAST WARRANTS MENTION OF SCATTERED THUNDERSTORMS DURING THIS
WEEKEND. BEST CHANCES APPEAR TO BE SATURDAY EVENING WHEN THE FRONTAL
SYSTEM IS PROJECTED TO CROSS THE AREA. WEAK CHANCES WILL EXIST
SATURDAY AFTERNOON AND AGAIN ON SUNDAY INTO SUNDAY NIGHT. SINCE THE
MODELS HAVE YET TO COME TO A CONSENSUS SOLUTION AND REMAIN
INCONSISTENT...KEPT CHANCES BELOW THE "LIKELY" CATEGORY...FOR NOW.
PRECIP CHANCES WILL QUICKLY BEGIN TO DWINDLE BY EARLY MONDAY
MORNING AS A RIDGE OF HIGH PRESSURE QUICKLY REESTABLISHES ITS
HOLD OVER THE REGION. DRY CONDITIONS ARE GENERALLY EXPECTED TO
KICK OFF THE WORK WEEK. AND TEMPERATURES WILL HAVE SLOWLY
ACCLIMATED BACK TO SEASONAL NORMAL BY MONDAY. WELCOME BACK
SUMMER...
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 252 PM EDT FRI AUG 28 2015
BROAD UPPER RIDGING WILL BE ACROSS THE AREA DURING THE LONG TERM.
HOWEVER THE INFLUENCE OF MOISTURE FROM ERIKA NOW LOOKS LIKE IT COULD
COME INTO PLAY IN THE MIDWEST/OHIO VALLEY DURING THE WEEK. WITH
MODELS TRENDING TOWARD BRINGING SOME ENERGY AROUND THE UPPER RIDGE
AND BRING MOISTURE NORTH THOUGHT IT PRUDENT TO FOLLOW THAT TREND AND
INCLUDE SOME SLIGHT CHANCES FOR THUNDERSTORMS DURING THE DAY FROM
WEDNESDAY THROUGH FRIDAY. THE INITIALIZATION FOLLOWED THIS TREND AS
WELL AND JUST NEEDED SOME QUALITY CONTROL TWEAKS. TEMPERATURE-WISE
LOOKING AT HIGHS JUST ABOVE NORMAL IN THE MID TO UPPER 80S FROM THE
INITIALIZATION AND THESE LOOK GOOD. HIGHS IN THE 90S NOT OUT OF THE
QUESTION BUT SHOULD ONLY BE ATTAINABLE IF THE TROPICAL MOISTURE
DOESN/T MAKE IT THIS WAY.
&&
.AVIATION /DISCUSSION FOR 290000Z TAF ISSUANCE/...
ISSUED AT 636 PM EDT FRI AUG 28 2015
VFR EXPECTED THROUGH THE PERIOD.
ANY LINGERING CUMULUS WILL DISSIPATE AFTER SUNSET LEAVING BEHIND
INCREASING MID AND HIGH CLOUDS DURING THE NIGHT. THESE CLOUDS
SHOULD HELP KEEP ANY FOG AT BAY.
A WEAK SYSTEM WILL MOVE IN ON SATURDAY AND WILL GENERATE SOME
SCATTERED CONVECTION IN THE AFTERNOON...WITH BEST CHANCES ARRIVING IN
THE EVENING AFTER 00Z. EVEN THEN ODDS WILL BE TOO LOW TO MENTION IN
TAFS.
LIGHT WINDS OVERNIGHT WILL BECOME SOUTHWEST ON SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF/50
SHORT TERM...SMF
LONG TERM....CP
AVIATION...50
AREA FORECAST DISCUSSION
NWS DES MOINES IA
647 PM CDT FRI AUG 28 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 358 PM CDT FRI AUG 28 2015
HEAVY RAIN WILL PERSIST ACROSS THE NORTHEAST THROUGH THE
EVENING. LATEST HRRR RUN KEEPS CONVECTION GOING IN THE FAR EAST
THROUGH 04-05Z TIME FRAME AND LEANED TOWARD THIS SOLUTION FOR
POPS/WX. THE WARM RAIN PROCESSES CURRENTLY AFFECTING THE FLASH FLOOD
WARNED AREAS ARE PRODUCING 2-4 INCH PER HOUR RAINFALL RATES. STRONG
DEEP MOISTURE CONVERGENCE OVER THE WATERLOO AREA WITH ROUGHLY 1.5-2
INCH PRECIPITABLE WATER AND WARM CLOUD DEPTHS TO AROUND 4000 METERS
IS ENOUGH TO CONTINUE THE HEAVY RAIN THREAT BEFORE SURFACE LOW IN
WESTERN IOWA PUSHES FURTHER EAST LATER THIS EVENING. POTENTIAL FOR
HEAVY RAIN TO CONTINUE IN THE EAST TO NORTHEAST SECTIONS OF THE
FORECAST AREA THROUGH 03Z TONIGHT...TO COINCIDE WITH THE LATEST HRRR
THINKING. OTHER CONCERN IS FOG OVERNIGHT WITH PLENTY OF MOISTURE AND
VERY LITTLE FLOW AT THE SURFACE A WEAK SURFACE RIDGE BUILDS INTO
WESTERN IOWA. HAVE MENTIONED PATCHY FOG PAST 09Z WEST OF I-35.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 358 PM CDT FRI AUG 28 2015
THE WEATHER WILL GENERALLY BE QUIET IN THE LONGER TERM WITH UPPER
RIDGING BUILDING INTO THE CENTRAL UNITED STATES. THICKNESSES WILL
INCREASE WITH TEMPERATURES CORRESPONDINGLY RESPONDING WITH HIGHS
CLIMBING ABOVE NORMAL...LIKELY TOWARD 90 BY EARLY NEXT
WEEK...ESPECIALLY IN THE SOUTH AND WEST. BOTH GFS AND EURO
INDICATED A WEAK SYSTEM PULLING NORTHEAST ON TUESDAY INTO THE
PLAINS WHICH MAY BRING THE THREAT OF ISOLATED THUNDER INTO THE
NORTHWEST PORTIONS OF IOWA BY LATER IN THE DAY INTO TUESDAY NIGHT.
OTHERWISE...THE RIDGE WILL REMAIN IN PLACE INTO LATE IN THE WEEK
WITH THE VERY WARM TEMPERATURES AND LITTLE THREAT OF PRECIPITATION.
&&
.AVIATION...29/00Z
ISSUED AT 647 PM CDT FRI AUG 28 2015
SFC LOW STILL OVR SW IA WITH A WARM FRONT EXTENDING TO NEAR THE
HIGHWAY 30 CORRIDOR AND NE. THE BOUNDARY WILL BE THE FOCUS FOR HVY
RN. GENERAL IFR CONDITIONS WILL PERSIST IN LOW CIGS AND VSBYS DUE
TO HEAVY RAIN THROUGH 03Z THEN FG AFT 06Z. THERE WILL BE A GRADUAL
IMPROVEMENT AFTER 15Z FROM W TO E AND MOST OF THE PRECIP...EXCEPT
FOR THE FAR EAST WILL END BY 06Z. SFC FLOW OVR SE IA WILL BE SRLY
AT 15-25KTS BEHIND THE SYSTEM SFC WND WILL BECOME ERLY THEN NRLY AT
5-10KTS AND WILL BE VERY LIGHT OVERNIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...FAB
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
241 PM CDT THU AUG 27 2015
...Updated long term discussion...
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 117 PM CDT THU AUG 27 2015
Models remain in good agreement with an upper level trough
crossing the Central High Plains overnight as a surface
boundary/weak cold front crosses southwestern Kansas. Water vapor
loop earlier this morning indicated an upper level disturbance,
located over southern Colorado at 12z Thursday. Dprog/dt along
with the RAP and NAM suggesting that this disturbance will precede
the main upper trough and will be crossing southwest Kansas
between 18z Thursday and 00z Friday. Based on the timing of the
southern Colorado upper wave along with 700mb moisture, 700mb
frontogenesis, and afternoon mid level instability ahead of this
wave late day will be leaning towards the HRRR,RAP,ARW, and NMM
with the better chances for scattered thunderstorms developing
along and east of a Dighton to Hugoton line. the main hazards from
these storms still appear to be hail quarter size and smaller
along with wind gusts of near 60 mph based on the latest RAP 0-6km
shear and CAPE values late today and early this evening. Periods
of moderate to heavy rainfall will also be possible, especially
east of highway 283. These thunderstorms are expected to move east
overnight as another area of scattered thunderstorms develop
further west near the weak cold front/surface boundary as it and
the main upper trough crosses western Kansas between 03z and 12z
Friday. Severe weather is not anticipated with these storms,
however moderate rainfall and lightning still will be likely.
A few lingering thunderstorms will be possible across south
central Kansas early Friday morning, however as the upper level
trough moves east towards the mid Mississippi valley these storms
will quickly end and skies will begin to clear from west to east.
As the weak cold front continues to move south across Oklahoma
during the day the 900mb to 850mb temperatures will cool. 850mb
mix down temperatures at 00z Saturday continue to supports highs
mainly in the 85 to 90 degree range.
.LONG TERM...(Friday NIGHT THROUGH Thursday)
ISSUED AT 240 PM CDT THU AUG 27 2015
High pressure at the surface will build across western Kansas
Friday night so winds will decrease to less than 10 knots after
sunset. Given these winds and clear/mostly clear conditions will
trend towards undercutting guidance for lows. Will favor
temperatures falling back into the mainly the upper 50s to lower
60s.
From Saturday through the beginning of next week an upper level
ridge will build and shift eastward into the Central and Northern
Plains. This trend continues to support the previous forecast with
a gradual warming trend through early next week. Highs will be
rebounding from the upper 80s to around 90 on Saturday to at least
the low to mid 90s on Monday and Tuesday.
Towards mid week a southwesterly flow will develop across the
Central High Plains. The GFS and ECMWF also suggest some tropical
moisture will try to return to Colorado and portions of western
Kansas. This may limit how warm temperatures will get around mid
week. There will also be a slightly better chance for afternoon
and evening thunderstorms along a surface boundary which is
expected to be located near the Colorado border should any subtle
upper wave be embedded in the southwesterly flow.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1209 PM CDT THU AUG 27 2015
Clouds will thicken and lower this afternoon as a Colorado upper
level trough moves east towards western Kansas. At this time based
on the NAM BUFR along with the RAP and NMM the VFR ceilings by
late day/early evening will lower to around 3500 ft AGL. In
addition to the lowering ceilings there will also be a chance for
thunderstorms ahead of the upper level trough late today and early
tonight. DDC and HYS will have the better opportunity for
convection for thunderstorms between 21z Thursday and 03z Friday.
GCK also has a chance but it appears to be prior to 00z Friday,
and the probability is less than 50 percent. As this upper level
trough passes the chance for storms will end and skies will begin
to slowly clear. Gusty southwest winds will continue until a cold
front crosses southwest Kansas between 03z and 09z Friday. As this
cold front passes the winds will shift to the north at 10 to 15
knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 88 60 89 / 50 10 0 0
GCK 64 88 59 89 / 40 10 0 0
EHA 64 88 59 89 / 30 10 10 0
LBL 66 89 60 90 / 50 10 0 0
HYS 65 87 59 89 / 60 10 0 0
P28 70 91 63 90 / 30 20 10 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Burgert
AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
119 PM CDT THU AUG 27 2015
...Updated short term discussion...
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 117 PM CDT THU AUG 27 2015
Models remain in good agreement with an upper level trough
crossing the Central High Plains overnight as a surface
boundary/weak cold front crosses southwestern Kansas. Water vapor
loop earlier this morning indicated an upper level disturbance,
located over southern Colorado at 12z Thursday. Dprog/dt along
with the RAP and NAM suggesting that this disturbance will precede
the main upper trough and will be crossing southwest Kansas
between 18z Thursday and 00z Friday. Based on the timing of the
southern Colorado upper wave along with 700mb moisture, 700mb
frontogenesis, and afternoon mid level instability ahead of this
wave late day will be leaning towards the HRRR,RAP,ARW, and NMM
with the better chances for scattered thunderstorms developing
along and east of a Dighton to Hugoton line. the main hazards from
these storms still appear to be hail quarter size and smaller
along with wind gusts of near 60 mph based on the latest RAP 0-6km
shear and CAPE values late today and early this evening. Periods
of moderate to heavy rainfall will also be possible, especially
east of highway 283. These thunderstorms are expected to move east
overnight as another area of scattered thunderstorms develop
further west near the weak cold front/surface boundary as it and
the main upper trough crosses western Kansas between 03z and 12z
Friday. Severe weather is not anticipated with these storms,
however moderate rainfall and lightning still will be likely.
A few lingering thunderstorms will be possible across south
central Kansas early Friday morning, however as the upper level
trough moves east towards the mid Mississippi valley these storms
will quickly end and skies will begin to clear from west to east.
As the weak cold front continues to move south across Oklahoma
during the day the 900mb to 850mb temperatures will cool. 850mb
mix down temperatures at 00z Saturday continue to supports highs
mainly in the 85 to 90 degree range.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 150 AM CDT THU AUG 27 2015
WE WILL SEE A TEMPORARY REPRIEVE FROM THE HEAT FRIDAY AND SATURDAY
AS SLIGHTLY COOLER 850-HPA TEMPERATURES ADVECT IN THE WAKE OF THE FRONT.
EXPECTING UPPER 80S FOR THESE DAYS. THE HEAT WILL RETURN WITH 90S LIKELY
BY SUNDAY AND CONTINUING THROUGH MUCH OF THE EXTENDED PERIOD. THE EXTENDED
MODELS SHOW UPPER LEVEL RIDGING ACROSS THE SOUTHERN TO CENTRAL PLAINS
WITH LEE TROUGHING ACROSS THE HIGH PLAINS. THE SUPERBLEND HAS ISOLATED
15-20 PERCENT POPS TUESDAY AND WEDNESDAY. I SUPPOSE AN ISOLATED STORM
COULD FORM ALONG THE LEE TROUGH. ON THE OTHER HAND, WOULD NOT BE SURPRISED
IF MOST AREAS REMAIN HOT AND DRY SINCE ANY ACTIVITY WILL REMAIN WELL
ISOLATED IN NATURE. THE SUPERBLEND TEMPERATURES LOOK REASONABLE FOR
THIS SUMMER-TIME PATTERN WITH HIGHS IN THE 90S AND LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1209 PM CDT THU AUG 27 2015
Clouds will thicken and lower this afternoon as a Colorado upper
level trough moves east towards western Kansas. At this time based
on the NAM BUFR along with the RAP and NMM the VFR ceilings by
late day/early evening will lower to around 3500 ft AGL. In
addition to the lowering ceilings there will also be a chance for
thunderstorms ahead of the upper level trough late today and early
tonight. DDC and HYS will have the better opportunity for
convection for thunderstorms between 21z Thursday and 03z Friday.
GCK also has a chance but it appears to be prior to 00z Friday,
and the probability is less than 50 percent. As this upper level
trough passes the chance for storms will end and skies will begin
to slowly clear. Gusty southwest winds will continue until a cold
front crosses southwest Kansas between 03z and 09z Friday. As this
cold front passes the winds will shift to the north at 10 to 15
knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 88 60 89 / 50 10 0 0
GCK 64 88 59 89 / 40 10 0 0
EHA 64 88 59 89 / 30 10 10 0
LBL 66 89 60 90 / 50 10 0 0
HYS 65 87 59 89 / 60 10 0 0
P28 70 91 63 90 / 20 20 10 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...SUGDEN
AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1213 PM CDT THU AUG 27 2015
...Updated synopsis and aviation discussion...
.SYNOPSIS...
ISSUED AT 1209 PM CDT THU AUG 27 2015
At 12z Thursday a 500mb trough was located over Colorado and
Wyoming. 40 to 50 meter 500mb 12 hour height falls were observed
east of the upper trough at North Platte and Denver. A 700mb
trough was located over eastern Colorado and western Nebraska.
700mb temperatures at 12z Thursday varied from +10c at Topeka to
+13c at Dodge City and Denver to +14c at North Platte. At the
surface a weak stationary front extended from southwest Nebraska
into central Kansas. A trough of low pressure extended from north
to south across far eastern Colorado.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 111 AM CDT THU AUG 27 2015
A SYNOPTIC DISTURBANCE CURRENTLY LOCATED ACROSS WESTERN WYOMING WILL
ROUND THE EDGE OF A LARGE ANTICYCLONE TO THE SOUTH. THIS UPPER LEVEL
DISTURBANCE WILL EVENTUALLY EJECT OUT ACROSS THE CENTRAL AND NORTHERN
PLAINS LATER TODAY. AS THIS DOES, THIS FEATURE WILL USHER IN THE PASSAGE
OF A WEAK FRONT ACROSS KANSAS. LATE AFTERNOON AND EVENING STORMS WILL
DEVELOP ALONG THIS BOUNDARY. HAVE THE HIGHEST POPS FROM HAYS, DOWN TO
NEAR DODGE CITY, AND WRAPPING BACK UP TO THE NORTHEAST TOWARDS STAFFORD
COUNTY. THIS IS A BLEND OF THE TWO ARW/WRF CORES, WHICH SHOWS THE STRONGEST
FRONTOGENESIS IN THIS REGION. A LOW TO MODERATE AMOUNT OF SBCAPE IS
FORECAST TO DEVELOP (1000-2000 J/KG). BULK SHEAR WILL BE WEAK TOO (20-30
KT). THE MAIN THREATS WITH THE STORMS ARE 50-60 MPH WINDS, NICKEL TO
QUARTER SIZE HAIL AND MODERATE RAINFALL AMOUNTS. UNDER THE STRONGEST
STORM, WOULD NOT RULE OUT 1" OF RAIN. MORE REALISTICALLY, RAIN AMOUNTS
WILL BE SPOTTY WITH LOWER AMOUNTS OF LESS THAN INCH FOR MUCH OF THE
REGION. HAVE POPS TAPERING QUICKLY THROUGH THE OVERNIGHT PERIOD. SOME
OF THE MODELS CONTINUE PRECIP THROUGH EARLY FRIDAY MORNING AS A WEAK
LOW LEVEL JET DEVELOPS AND HELPS WITH LIFT. OTHERWISE, HIGHS TODAY
ARE EXPECTED TO BE IN THE 90S WITH LOWS IN MAINLY IN THE 60S FOR FRIDAY
MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 150 AM CDT THU AUG 27 2015
WE WILL SEE A TEMPORARY REPRIEVE FROM THE HEAT FRIDAY AND SATURDAY
AS SLIGHTLY COOLER 850-HPA TEMPERATURES ADVECT IN THE WAKE OF THE FRONT.
EXPECTING UPPER 80S FOR THESE DAYS. THE HEAT WILL RETURN WITH 90S LIKELY
BY SUNDAY AND CONTINUING THROUGH MUCH OF THE EXTENDED PERIOD. THE EXTENDED
MODELS SHOW UPPER LEVEL RIDGING ACROSS THE SOUTHERN TO CENTRAL PLAINS
WITH LEE TROUGHING ACROSS THE HIGH PLAINS. THE SUPERBLEND HAS ISOLATED
15-20 PERCENT POPS TUESDAY AND WEDNESDAY. I SUPPOSE AN ISOLATED STORM
COULD FORM ALONG THE LEE TROUGH. ON THE OTHER HAND, WOULD NOT BE SURPRISED
IF MOST AREAS REMAIN HOT AND DRY SINCE ANY ACTIVITY WILL REMAIN WELL
ISOLATED IN NATURE. THE SUPERBLEND TEMPERATURES LOOK REASONABLE FOR
THIS SUMMER-TIME PATTERN WITH HIGHS IN THE 90S AND LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1209 PM CDT THU AUG 27 2015
Clouds will thicken and lower this afternoon as a Colorado upper
level trough moves east towards western Kansas. At this time based
on the NAM BUFR along with the RAP and NMM the VFR ceilings by
late day/early evening will lower to around 3500 ft AGL. In
addition to the lowering ceilings there will also be a chance for
thunderstorms ahead of the upper level trough late today and early
tonight. DDC and HYS will have the better opportunity for
convection for thunderstorms between 21z Thursday and 03z Friday.
GCK also has a chance but it appears to be prior to 00z Friday,
and the probability is less than 50 percent. As this upper level
trough passes the chance for storms will end and skies will begin
to slowly clear. Gusty southwest winds will continue until a cold
front crosses southwest Kansas between 03z and 09z Friday. As this
cold front passes the winds will shift to the north at 10 to 15
knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 97 66 88 60 / 50 50 10 0
GCK 96 64 88 59 / 30 40 10 0
EHA 95 64 88 59 / 40 40 10 10
LBL 98 66 89 60 / 40 50 10 0
HYS 98 65 87 59 / 60 60 10 0
P28 98 70 91 63 / 30 30 20 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...SUGDEN
LONG TERM...SUGDEN
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS GOODLAND KS
208 AM MDT THU AUG 27 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 110 PM MDT WED AUG 26 2015
WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS
THE PLAINS WITH 596 DM CENTER AXIS EXTENDING NORTH OVER OUR CWA.
SHORTWAVE TROUGH IS CURRENTLY ROTATING AROUND WESTERN EDGE OF RIDGE
WITH MOISTURE PLUME EXTENDING ACROSS THE CENTRAL ROCKIES AHEAD OF
THIS FEATURE. AT THE SURFACE LO PRESSURE EXTENDS FROM EASTERN
MONTANA ACROSS EASTERN COLORADO AND OVER OUR CWA. A WEAK
STATIONARY FRONT IS CURRENTLY IN PLACE FROM SW NEBRASKA AND ACROSS
CENTRAL KANSAS (NEAR HLC).
THIS AFTERNOON-TONIGHT...VERY DRY AIR MASS...STRONG CAP...AND
LIMITED LARGE SCALE FORCING WILL CONTINUE TO LIMIT CONVECTIVE
POTENTIAL. CAP MAY BEGIN TO WEAKEN ALONG STALLED FRONT IN OUR
EASTERN CWA LATER THIS AFTERNOON...HOWEVER AT THIS POINT
CONFIDENCE IS TOO LOW TO INCLUDE A MENTION OF
SHOWERS/THUNDERSTORMS. AS WAS EXPECTED HOT TEMPERATURES AND
FAVORABLE MIXING HAVE RESULTED IN VERY LOW RH VALUES THIS
AFTERNOON ACROSS THE WESTERN HALF OF OF OUR FORECAST AREA...WITH
SOME LOCATIONS GUSTING TO NEAR RFW CRITERIA. WITH FUELS STILL NOT
CONSIDERED FAVORABLE FOR RAPID FIRE SPREAD I HAVE HELD BACK ON RFW
ISSUANCE.
THURSDAY...UPPER LEVEL TROUGH WILL ROTATE AROUND THE NORTH SIDE OF
THE RIDGE AND DEEPEN AS IT TRACKS ACROSS THE NORTHERN PLAINS.
LARGE SCALE FORCING WILL OVERSPREAD OUR CWA ON THE SOUTHERN EXTENT
OF THIS FEATURE...WITH DRY AIR MASS INITIALLY LIMITING CONVECTIVE
COVERAGE UNTIL LATER THURSDAY AFTERNOON. RETURN FLOW AHEAD OF
APPROACHING FRONT MAY LEAD TO INCREASED TDS AND HIGHER CAPE VALUES
ACROSS OUR EASTERN CWA. GFS AND NAM BOTH SHOWING VERY DIFFERENT
PICTURE REGARDING MOISTURE/CAPE PROFILES WITH NAM SHOWING BETTER
MOISTURE RETURN AND HIGHER CAPE BY 00Z. EFFECTIVE SHEER VALUES
35KT OR HIGHER WILL BE POSSIBLE...SO IF THE MORE AGGRESSIVE
GUIDANCE WAS TO VERIFY WE COULD SEE A MORE ORGANIZED SEVERE THREAT
ROUGHLY ALONG/EAST OF HIGHWAY 83. REGARDLESS OF SEVERE
THREAT...GFS/NAM BOTH SHOW THE BEST PRECIP SIGNAL IN OUR
EAST/SOUTHEAST ALONG PRE FRONTAL TROUGH...AND I RAISED POPS
ACCORDINGLY.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 206 AM MDT THU AUG 27 2015
THE RIDGE SITUATED OVER THE HIGH PLAINS ON SUNDAY WILL GRADUALLY
TRANSITION EAST AND NORTHEASTWARD AS WE HEAD INTO MONDAY. THIS WILL
ALLOW THE UPPER FLOW PATTERN TO TRANSITION TO A MORE WESTERLY TO
SOUTHWESTERLY FLOW AND USHER IN MONSOONAL MOISTURE. THERE IS GOOD
CONFIDENCE IN DAILY RAIN AND THUNDERSTORM CHANCES OF 20 TO 30
PERCENT ESPECIALLY IN THE WESTERN AND NORTHWESTERN PORTIONS OF THE
CWA AS A THETA E BOUNDARY WILL SET UP FROM SOUTHWEST TO NORTHEAST
ACROSS THIS REGION. THE BEST POPS WILL FOCUS ALONG THIS BOUNDARY.
SEVERE THUNDERSTORMS ARE POSSIBLE HOWEVER THE CAPE AND SHEAR INDICES
ARE VERY WEAK TO MARGINAL AT BEST. BOTH THE GFS AND ECMWF AGREE WITH
REGARDS TO THE OVERALL PATTERN BUT THE LATEST RUNS DO NOT AGREE AS
WELL AS SOME OF THE PREVIOUS RUNS. OVERALL THE PATTERN WILL BECOME
AMPLIFIED AND FAVOR RIDGING IN THE EASTERN US WITH A DEEP TROUGH
DEVELOPING OVER THE WESTERN STATES AND THE INTERMOUNTAIN WEST.
TEMPERATURES DURING THIS PERIOD WILL REMAIN SLIGHTLY ABOVE THE
SEASONAL AVERAGE WITH HIGHS IN THE UPPER 80S TO LOWER 90S AND LOWS
IN THE LOW TO MID 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1121 PM MDT WED AUG 26 2015
PREFRONTAL TROUGH AND COLD FRONT WILL MOVE THROUGH THE TERMINALS
ON THURSDAY...EACH ACCOMPANIED BY A WIND SHIFT. THE TROUGH WILL
SHIFT WINDS TO SOUTHWEST AND THE FRONT TO NORTHWEST. SCATTERED
SHOWERS AND THUNDERSTORMS WILL ALSO DEVELOP BUT DUE TO LIMITED
COVERAGE WILL NOT MENTION IN EITHER TAF ATTM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TL
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1123 PM MDT WED AUG 26 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 110 PM MDT WED AUG 26 2015
WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS
THE PLAINS WITH 596 DM CENTER AXIS EXTENDING NORTH OVER OUR CWA.
SHORTWAVE TROUGH IS CURRENTLY ROTATING AROUND WESTERN EDGE OF RIDGE
WITH MOISTURE PLUME EXTENDING ACROSS THE CENTRAL ROCKIES AHEAD OF
THIS FEATURE. AT THE SURFACE LO PRESSURE EXTENDS FROM EASTERN
MONTANA ACROSS EASTERN COLORADO AND OVER OUR CWA. A WEAK
STATIONARY FRONT IS CURRENTLY IN PLACE FROM SW NEBRASKA AND ACROSS
CENTRAL KANSAS (NEAR HLC).
THIS AFTERNOON-TONIGHT...VERY DRY AIR MASS...STRONG CAP...AND
LIMITED LARGE SCALE FORCING WILL CONTINUE TO LIMIT CONVECTIVE
POTENTIAL. CAP MAY BEGIN TO WEAKEN ALONG STALLED FRONT IN OUR
EASTERN CWA LATER THIS AFTERNOON...HOWEVER AT THIS POINT
CONFIDENCE IS TOO LOW TO INCLUDE A MENTION OF
SHOWERS/THUNDERSTORMS. AS WAS EXPECTED HOT TEMPERATURES AND
FAVORABLE MIXING HAVE RESULTED IN VERY LOW RH VALUES THIS
AFTERNOON ACROSS THE WESTERN HALF OF OF OUR FORECAST AREA...WITH
SOME LOCATIONS GUSTING TO NEAR RFW CRITERIA. WITH FUELS STILL NOT
CONSIDERED FAVORABLE FOR RAPID FIRE SPREAD I HAVE HELD BACK ON RFW
ISSUANCE.
THURSDAY...UPPER LEVEL TROUGH WILL ROTATE AROUND THE NORTH SIDE OF
THE RIDGE AND DEEPEN AS IT TRACKS ACROSS THE NORTHERN PLAINS.
LARGE SCALE FORCING WILL OVERSPREAD OUR CWA ON THE SOUTHERN EXTENT
OF THIS FEATURE...WITH DRY AIR MASS INITIALLY LIMITING CONVECTIVE
COVERAGE UNTIL LATER THURSDAY AFTERNOON. RETURN FLOW AHEAD OF
APPROACHING FRONT MAY LEAD TO INCREASED TDS AND HIGHER CAPE VALUES
ACROSS OUR EASTERN CWA. GFS AND NAM BOTH SHOWING VERY DIFFERENT
PICTURE REGARDING MOISTURE/CAPE PROFILES WITH NAM SHOWING BETTER
MOISTURE RETURN AND HIGHER CAPE BY 00Z. EFFECTIVE SHEER VALUES
35KT OR HIGHER WILL BE POSSIBLE...SO IF THE MORE AGGRESSIVE
GUIDANCE WAS TO VERIFY WE COULD SEE A MORE ORGANIZED SEVERE THREAT
ROUGHLY ALONG/EAST OF HIGHWAY 83. REGARDLESS OF SEVERE
THREAT...GFS/NAM BOTH SHOW THE BEST PRECIP SIGNAL IN OUR
EAST/SOUTHEAST ALONG PRE FRONTAL TROUGH...AND I RAISED POPS
ACCORDINGLY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 225 PM MDT WED AUG 26 2015
A RIDGE WILL MOVE INTO THE ROCKIES THROUGH FRIDAY NIGHT AND THEN
START MOVING INTO THE PLAINS SATURDAY. A SURFACE TROUGH WILL MOVE
EAST ACROSS NORTHWEST KANSAS THURSDAY NIGHT FOLLOWED BY HIGH
PRESSURE WHICH SHOULD LINGER OVER THE PLAINS THROUGH SATURDAY.
A SHORTWAVE MOVING OVER THE TOP OF THE RIDGE WILL BE EXITING THE FA
THURSDAY EVENING. PLAN TO CONTINUE CHANCE/SLIGHT CHANCE POPS FOR THE
EVENING. DYNAMICS SHOULD BE EXITING THE FA AROUND 06Z FRIDAY.
SUBSIDENCE BUILDS INTO THE FA FRIDAY AND CONTINUES THROUGH SATURDAY.
POPS WILL BE NIL FOR THOSE PERIODS.
MIN TEMPERATURES SHOULD RANGE FROM THE UPPER 50S IN EASTERN COLORADO
TO THE LOWER 60S ELSEWHERE. MAX TEMPERATURES SHOULD REACH THE MID
AND UPPER 80S.
IN THE EXTENDED...(SATURDAY NIGHT THROUGH WEDNESDAY)...
THE UPPER RIDGE WILL REMAIN OVER THE PLAINS THROUGH SUNDAY AND THEN
MOVE EAST OF THE PLAINS MONDAY. THE FORECAST WILL REMAIN DRY
THROUGH MONDAY DUE TO THE LACK OF SUFFICIENT MOISTURE AND FORCING.
HOWEVER BY MONDAY EVENING MONSOONAL MOISTURE WILL BEGIN TO IMPACT
THE AREA WITH A SLIGHT CHANCE OF THUNDERSTORMS EACH AFTERNOON AND
EVENING THROUGH WEDNESDAY.
MIN TEMPERATURES SHOULD COOL TO THE LOWER AND MID 60S. MAX
TEMPERATURES SHOULD REACH THE LOWER 90S EACH DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1121 PM MDT WED AUG 26 2015
PREFRONTAL TROUGH AND COLD FRONT WILL MOVE THROUGH THE TERMINALS
ON THURSDAY...EACH ACCOMPANIED BY A WIND SHIFT. THE TROUGH WILL
SHIFT WINDS TO SOUTHWEST AND THE FRONT TO NORTHWEST. SCATTERED
SHOWERS AND THUNDERSTORMS WILL ALSO DEVELOP BUT DUE TO LIMITED
COVERAGE WILL NOT MENTION IN EITHER TAF ATTM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...024
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1205 AM EDT THU AUG 27 2015
.SYNOPSIS...
AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL APPROACH TONIGHT AND MOVE
OVER THE REGION ON THURSDAY. THE TROUGH WILL LIFT NORTHEAST OF THE
AREA THURSDAY NIGHT. HIGH PRESSURE WILL BUILD ALONG THE MID ATLANTIC
COAST FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
1205 AM UPDATE...THE LAST OF THE LIGHTNING HAS NOW MOVED EAST OF
THE CWA INTO NEW BRUNSWICK. THERE ARE STILL A FEW SHOWERS ACROSS
FAR EASTERN PORTIONS OF THE AREA THAT WILL END OVERNIGHT AS A COLD
FRONT CONTINUES TO MOVE EAST OF THE AREA. ONLY MINOR ADJUSTMENTS
TO THE ONGOING FORECAST BASED ON THE LATEST OBSERVATIONS AND RADAR
TRENDS. NOTED THAT THE HRRR APPEARS TOO VIGOROUS IN ATTEMPTING TO
GENERATE ADDITIONAL SHOWERS ACROSS CENTRAL AND NORTHEAST PORTIONS
OF THE CWA POST FRONTAL OVERNIGHT.
ORGNL DISC: SFC BNDRY HAS SLOWLY CREEPED INTO EXTRM WRN PART OF
CWA WITH NW WIND AT GREENVILLE AND SE WIND AT MILLINOCKET. THIS
BNDRY IS ALLOWING MOISTURE TO STREAM NWRD ON 30KT H8 LLJ. SHOWERS
AND ISOLD STORMS CONTINUE TO RE-DEVELOP AT THIS TIME. EXPECT THESE
WL CONTINUE OFF AND ON INTO THE EVNG HRS. BIGGEST CONCERN CONTS TO
CENTER ARND WASHINGTON CNTY. THIS AREA WAS HIT HARD THIS MRNG WITH
HVY RAIN AND FLOODING AS A RESULT OF LFQ OF H2 JET. MED RANGE
MODELS INDICATING ANOTHER JET DVLPNG LATE TONIGHT. THIS JET IS
BEING PICKED UP ON WV IMAGERY AT THIS TIME ALONG THE ERN SEABOARD.
AS THIS JET INTENSIFIES IT WL LKLY INDUCE SFC LOW DVLPMNT IN THE
GULF OF MAINE. UPR LVL SUPPORT FM JET MAX COUPLED WITH LOW-LVL
CONVERGENCE WITH SFC LOW AND PW VALUES OF 1.50+ INCHES WL LKLY LEAD
TO HVY RAINFALL AGAIN OVRNGT. WL HIGHLIGHT THREAT IN HWO AND ALLOW
LATER SHIFTS TO MAKE THE CALL ON A POSSIBLE WATCH. SFC LOPRES WL
RESULT IN SLOW MVMNT TO FRONT AND NOT CLR CWA UNTIL 12Z THUR.
ELEVATED INSTABILITY WL WANE ACRS MOST OF CWA AFT 00Z BUT WL
CONTINUE THRU ABOUT 06Z OVR WASHINGTON CNTY. THUS HV MAINTAINED
ISOLD THUNDER THRU THIS TIME.
DRY DWPTS WL FILTER INTO THE NW IN WAKE OF FROPA AS DWPTS ACRS
CANADA HV DROPPED INTO THE M50S. THUS, EXPECT THAT MINS OVRNGT IN
THE NORTH WOOD CUD DROP INTO THE M/U 50S WITH LOCALES ALONG THE
COAST IN THE L60S.
DRG THE DAY THURSDAY EXPECT UPR LVL TROF TO SWING THRU THE STATE.
THIS WL LEAD TO ANOTHER ROUND OF SHOWERS AND ISOLD THUNDER ACRS THE
CROWN OF MAINE. COLD TEMPS ALOFT WL MV THRU DRG THE AFTN AT TIME OF
MAX DIURNAL HTG.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
THE TROUGH OF LOW PRESSURE WHICH HAS BEEN BRINGING SHOWERS THE LAST
FEW DAYS WILL BE WEAKENING AND LIFTING OUT TO THE NORTHEAST THURSDAY
NIGHT AS HIGH PRESSURE BEGINS TO BUILD TOWARD THE MID ATLANTIC
REGION. THE HIGH WILL BRING MOSTLY SUNNY AND DRY WEATHER ON FRIDAY.
A WEAK FRONTAL BOUNDARY DROPPING DOWN FROM THE NORTH MAY BRING SOME
CLOUDINESS TO FAR NORTHERN AREAS LATE IN THE DAY. FRIDAY NIGHT WILL
BE CLEAR TO PARTLY CLOUDY. SATURDAY SHOULD THEN BE ANOTHER DRY DAY
AS HIGH PRESSURE MOVES OFF THE EAST COAST. SOME CLOUDS MAY INCREASE
LATE IN THE DAY AHEAD OF A WEAK TROUGH APPROACHING FROM THE WEST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE WEAK TROUGH MOVING ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY
WILL BRING A PARTLY TO MOSTLY CLOUDY DAY WITH THE CHANCE FOR SOME
SPOTTY SHOWERS OR A THUNDERSTORM, ESPECIALLY OVER THE NORTH WHERE A
WEAK FRONTAL BOUNDARY WILL BE PUSHING IN. THE TROUGH WILL QUICKLY
MOVE AWAY SUNDAY NIGHT. HIGH PRESSURE SUPPORTED BY STRONG UPPER
LEVEL RIDGING SHOULD THEN BUILD OVER THE AREA BRINGING SUNNY DRY
WEATHER ON MONDAY. RIDGING WILL CONTINUE TO SUPPORT SUNSHINE AND DRY
WEATHER ON TUESDAY WITH TEMPS A BIT WARMER AS A WEST SOUTHWESTERLY
BREEZE CIRCULATES IN BEHIND THE HIGH. DRY WEATHER SHOULD PERSIST
INTO MID WEEK DOWNEAST WHILE A WEAK FRONTAL BOUNDARY PUSHING INTO
THE NORTH WILL BRING A CHANCE FOR SHOWERS OVER NORTHERN AREAS ON
WEDNESDAY.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR CONDITIONS EXPECTED MAJORITY OF TAF VALID TIME IN
MOIST AND HUMID AIRMASS. AS DRIER AIR WORKS IN BEHIND FRONTAL
BOUNDARY OVERNIGHT AND EARLY THURSDAY MORNING EXPECT CONDITIONS
TO INCREASE TO MVFR AFTER DAYBREAK.
SHORT TERM: VFR CONDITIONS ARE EXPECTED THURSDAY NIGHT THROUGH
SATURDAY AS HIGH PRESSURE BUILDS SOUTH OF THE AREA. CONDITIONS MAY
LOWER TO MVFR AT TIMES SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND
SOME SHOWERS. CONDITIONS WILL RETURN TO VFR SUNDAY NIGHT AND
REMAIN VFR ON MONDAY AS HIGH PRESSURE RETURNS.
&&
.MARINE...
NEAR TERM: VISIBILITIES WILL BE REDUCED IN AREAS OF FOG OVERNIGHT.
THE WIND AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA. A FEW SHOWERS WILL BE POSSIBLE OVERNIGHT ACROSS THE
EASTERN MOST MARINE ZONE.
SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
THROUGH MID WEEK NEXT WEEK WITH HIGH PRESSURE SOUTH OF THE WATERS
EARLY THIS WEEKEND AND ANOTHER HIGH OVER THE WATERS EARLY NEXT
WEEK.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CB/VJN
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...CB/VJN/BLOOMER
MARINE...CB/VJN/BLOOMER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
754 PM EDT FRI AUG 28 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 411 PM EDT FRI AUG 28 2015
WV IMAGERY AND RAP ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL
FLOW ALONG THE US/CANADIAN BORDER. A SHORTWAVE TROUGH FROM NW
ONTARIO INTO NRN MN SUPPORTED SCT SHRA/TSRA OVER THE MN ARROWHEAD
INTO NRN ONTARIO WEST OF THUNDER BAY. TO THE SOUTH...ANOTHER SHRTWV
OVER IA BRINGING SHOWERS FROM NE IA THROUGH SW WI WAS SLOWLY LIFTING
TO THE ENE. THE LEADING EDGE OF THE PCPN TO NEAR AUW.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES PREVAILED ACROSS UPPER MI
WITH TEMPS IN THE MID 70S.
TONIGHT...MOST OF THE CWA WILL REMAIN BETWEEN THE INFLUENCE OF THE
NRN AND SRN STREAM SHORTWAVES. RADAR TRENDS AND SHORT RANGE MODELS
SUGGEST THAT THE RAIN OVER WI TO AFFECT MAINLY THE SRN TIER ALONG
AND SOUTH OF US-2 FROM IMT EASTWARD. SHRA/TSRA WITH THE NRN STREAM
SHRTWV MAY BRUSH MAINLY THE KEWEENAW BY LATE THIS EVENING AND
POSSIBLY INTO THE NRN PORTION OF UPPER MI. FCST MUCAPE VALUES INTO
THE 500-1000 J/KG RANGE OVER THE NORTH COULD ALSO SUPPORT ISOLD
TSRA.
SATURDAY...SOME SHOWERS MAY LINGER OVER THE SE PORTION OF THE CWA
ASSOCIATED WITH REMNANTS OF THE WI SHRTWV OR POSSIBLY AIDED BY A
TRAILING SHRTWV DIVING INTO NRN WI. HOWEVER...EXPECT THE PCPN TO
SLIDE OFF TO THE EAST BY AFTERNOON. WITH SOME CLEARING INTO THE WEST
HALF BY AFTERNOON...TEMPS WILL REBOUND INTO THE MID AND UPPER 70.
GREATER CLOUD COVER OVER THE EAST AND WITH SRLY FLOW OFF OF LAKE
MI...TEMPS WILL REMAIN IN UPPER 60S AND LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM EDT FRI AUG 28 2015
COULD SEE A FEW SHOWERS IN THE FIRST 6 HOURS OF THE FORECAST SAT
NIGHT...BUT THINK VAST MAJORITY OF PRECIP ASSOCIATED WITH A
SHORTWAVE WILL BE OUT OF THE AREA. OTHERWISE...PRECIP CHANCES ARE
LOW IN THE LONG TERM AS A MID-UPPER RIDGE MOVES IN AND SITS OVER THE
CENTRAL TO ERN CONUS. COULD SEE SOME PRECIP MID-LATE NEXT WEEK AS
SHORTWAVES TRY TO TOP THE RIDGE...BUT PREDICTABILITY IS TOO LOW TO
JUSTIFY ANYTHING ABOVE SLIGHT CHANCE POPS.
TEMPS WILL BE ON THE INCREASE AND WILL ALREADY BE ABOVE NORMAL SUN.
HIGHS SUN WILL BE IN THE MID 70S TO LOW 80S AS 850MB TEMPS START OUT
IN THE MID TEENS C. 850MB TEMPS THROUGH THE REST OF THE WEEK WILL BE
AROUND 20C...RESULTING IN HIGH TEMPS 10 OR MORE DEGREES ABOVE
NORMAL.
COULD SEE SOME PATCHY FOG AROUND SAT NIGHT INTO EARLY SUN MORNING
AND AGAIN SUN NIGHT INTO MON MORNING AS HIGH PRESSURE/SUBSIDENCE
MOVES IN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 754 PM EDT FRI AUG 28 2015
VFR CONDITIONS WILL CONTINUE THROUGH THIS FCST PERIOD AT ALL SITES.
WILL BE MVFR BRIEFLY FOR CLOUDS AT KSAW SAT MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT FRI AUG 28 2015
EXPECT A PERIOD OF MODERATE SW WINDS LATE TONIGHT INTO EARLY GUSTING
TO 15-20 KNOTS. OTHERWISE...A GENERALLY WEAK PRES GRADIENT WILL
DOMINATE THE UPPER LAKES INTO EARLY NEXT WEEK. ON MOST DAYS...WINDS
WILL BE UNDER 15KT. LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE
WEEKEND WITH HIGH PRES RIDGE MORE FIRMLY IN CONTROL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
702 PM EDT THU AUG 27 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 411 PM EDT THU AUG 27 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW WNW FLOW INTO THE UPPER
GREAT LAKES. RIDGE THAT EXTENDED FROM THE SRN ROCKIES TO SCNTRL
CANADA YESTERDAY IS WEAKENING DUE TO SHORTWAVE ENERGY TRACKING FROM
NRN ALBERTA TO NRN MANITOBA AND ANOTHER SHORTWAVE MOVING FROM WY
INTO THE WRN PLAINS. THAT SHORTWAVE WILL BEGIN TO BECOME A FCST
ISSUE HERE ON FRI. AFTER MORNING FOG...THE DAY HAS TURNED MOSTLY
SUNNY...THOUGH AN ELEVATED SMOKE LAYER HAS LEFT THE SKY WITH A HAZY
APPEARANCE. TEMPS HAVE REBOUNDED INTO THE MID 60S TO LWR 70S.
QUIET WEATHER WILL CONTINUE TONIGHT AS DRY AIR IN A RELATIVE SENSE
DOMINATES MOST OF THE COLUMN. LIGHT SOUTHERLY WINDS AND AN INCREASE
IN PRECIPITABLE WATER WILL RESULT IN A WARMER NIGHT THAN LAST NIGHT.
EXPECT MINS MOSTLY IN THE 50S...THOUGH DOWNSLOPE AREAS NEAR LAKE
SUPERIOR MAY NOT FALL BLO 60F.
ON FRI...THE WRN PLAINS SHORTWAVE WILL MOVE TO WI. BEST
WAA/ISENTROPIC ASCENT ASSOCIATED WITH FEATURE SHIFTS FROM NRN IA/SRN
MN INTO WI...SO BULK OF PCPN WILL PASS BY TO THE S OF HERE. THAT
AREA IS ALSO WHERE MODELS SHOW HEAVIEST PCPN. PCPN CHANCES WILL BE
MUCH MORE LIMITED TO THE N. WHILE HIGH RES WRF-ARW/NMM ARE LIKELY
TOO AGGRESSIVE IN SPREADING PCPN INTO SCNTRL UPPER MI FRI...MOST
MODELS DO BRING SOME PCPN INTO THE SCNTRL IN THE AFTN. WILL PAINT
CHC POPS OVER THE FAR SCNTRL. DEPENDING ON CLOUD COVER/DAYTIME
HEATING...THE GFS AND ESPECIALLY NAM BUILD A LITTLE BIT OF
INSTABILITY PER MLCAPES FARTHER N. HAVE INCLUDED SCHC POPS FOR -SHRA
IN THE EVENT A FEW -SHRA MANAGE TO POP IN THE AFTN.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 301 PM EDT THU AUG 27 2015
PLENTY OF UNCERTAINTY IN THE FIRST 24 HOURS OF THE LONG TERM...FRI
NIGHT AND SAT. A SHORTWAVE IS SET TO MOVE OUT OF THE CENTRAL PLAINS
AND MOVE THROUGH OR NEAR THE REGION DURING THIS TIME. THE 00Z/27
ECMWF IS DEEPEST AND FARTHEST NORTH WITH THE SHORTWAVE...WITH RAIN
OVER MOST OF THE CWA. THE 12Z/27 GFS IS QUITE A BIT WEAKER AND
FARTHER S...KEEPING MOST OF THE CWA DRY. THE 12Z/27 GEM AND 12Z/27
NAM MATCH CLOSER TO THE GFS...BUT DO BRING SOME PRECIP INTO THE SRN
CWA. WILL TEND TO FAVOR A GFS/NAM/GEM CONSENSUS GIVEN HOW MUCH OF AN
OUTLIER THE ECMWF IS. THIS RESULTS IN CHANCE POPS OVER SCENTRAL UPPER
MI FRI NIGHT AND SAT MORNING AND SLIGHT CHANCE POPS ELSEWHERE. DRY
CONDITIONS EXPECTED BY 00Z SUN.
MODELS CONTINUE TO BUILD AN UPPER RIDGE OVER THE REGION FROM SUN
THROUGH THE REST OF NEXT WEEK. RAIN CHANCES WILL BE MINIMAL...BUT
COULD SEE SOME CONVECTION WED OR THU IF SHORTWAVE ENERGY CAN ROUND
THE TOP OF THE RIDGE...BUT CHANCES ARE LOW. THE AIRMASS WILL BE ON
THE RISE...HOVERING AROUND 20C FROM LATE MON THROUGH THE REST OF THE
WEEK. THIS RESULTS IN TEMPS BEING 10 OR MORE DEGREES ABOVE NORMAL
FROM MON ON.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 701 PM EDT THU AUG 27 2015
RELATIVELY DRY AIR MASS OVER THE AREA SHOULD ENSURE VFR CONDITIONS
CONTINUE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT THU AUG 27 2015
A GENERALLY WEAK PRES GRADIENT WILL DOMINATE THE UPPER LAKES INTO
EARLY NEXT WEEK. ON MOST DAYS...WINDS WILL BE UNDER 15KT...BUT THERE
WILL BE SOME PERIODS WHERE GUSTS WILL GET INTO THE 15-20KT RANGE.
LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE WEEKEND WITH HIGH
PRES RIDGE MORE FIRMLY IN CONTROL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT THU AUG 27 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 411 PM EDT THU AUG 27 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW WNW FLOW INTO THE UPPER
GREAT LAKES. RIDGE THAT EXTENDED FROM THE SRN ROCKIES TO SCNTRL
CANADA YESTERDAY IS WEAKENING DUE TO SHORTWAVE ENERGY TRACKING FROM
NRN ALBERTA TO NRN MANITOBA AND ANOTHER SHORTWAVE MOVING FROM WY
INTO THE WRN PLAINS. THAT SHORTWAVE WILL BEGIN TO BECOME A FCST
ISSUE HERE ON FRI. AFTER MORNING FOG...THE DAY HAS TURNED MOSTLY
SUNNY...THOUGH AN ELEVATED SMOKE LAYER HAS LEFT THE SKY WITH A HAZY
APPEARANCE. TEMPS HAVE REBOUNDED INTO THE MID 60S TO LWR 70S.
QUIET WEATHER WILL CONTINUE TONIGHT AS DRY AIR IN A RELATIVE SENSE
DOMINATES MOST OF THE COLUMN. LIGHT SOUTHERLY WINDS AND AN INCREASE
IN PRECIPITABLE WATER WILL RESULT IN A WARMER NIGHT THAN LAST NIGHT.
EXPECT MINS MOSTLY IN THE 50S...THOUGH DOWNSLOPE AREAS NEAR LAKE
SUPERIOR MAY NOT FALL BLO 60F.
ON FRI...THE WRN PLAINS SHORTWAVE WILL MOVE TO WI. BEST
WAA/ISENTROPIC ASCENT ASSOCIATED WITH FEATURE SHIFTS FROM NRN IA/SRN
MN INTO WI...SO BULK OF PCPN WILL PASS BY TO THE S OF HERE. THAT
AREA IS ALSO WHERE MODELS SHOW HEAVIEST PCPN. PCPN CHANCES WILL BE
MUCH MORE LIMITED TO THE N. WHILE HIGH RES WRF-ARW/NMM ARE LIKELY
TOO AGGRESSIVE IN SPREADING PCPN INTO SCNTRL UPPER MI FRI...MOST
MODELS DO BRING SOME PCPN INTO THE SCNTRL IN THE AFTN. WILL PAINT
CHC POPS OVER THE FAR SCNTRL. DEPENDING ON CLOUD COVER/DAYTIME
HEATING...THE GFS AND ESPECIALLY NAM BUILD A LITTLE BIT OF
INSTABILITY PER MLCAPES FARTHER N. HAVE INCLUDED SCHC POPS FOR -SHRA
IN THE EVENT A FEW -SHRA MANAGE TO POP IN THE AFTN.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 301 PM EDT THU AUG 27 2015
PLENTY OF UNCERTAINTY IN THE FIRST 24 HOURS OF THE LONG TERM...FRI
NIGHT AND SAT. A SHORTWAVE IS SET TO MOVE OUT OF THE CENTRAL PLAINS
AND MOVE THROUGH OR NEAR THE REGION DURING THIS TIME. THE 00Z/27
ECMWF IS DEEPEST AND FARTHEST NORTH WITH THE SHORTWAVE...WITH RAIN
OVER MOST OF THE CWA. THE 12Z/27 GFS IS QUITE A BIT WEAKER AND
FARTHER S...KEEPING MOST OF THE CWA DRY. THE 12Z/27 GEM AND 12Z/27
NAM MATCH CLOSER TO THE GFS...BUT DO BRING SOME PRECIP INTO THE SRN
CWA. WILL TEND TO FAVOR A GFS/NAM/GEM CONSENSUS GIVEN HOW MUCH OF AN
OUTLIER THE ECMWF IS. THIS RESULTS IN CHANCE POPS OVER SCENTRAL UPPER
MI FRI NIGHT AND SAT MORNING AND SLIGHT CHANCE POPS ELSEWHERE. DRY
CONDITIONS EXPECTED BY 00Z SUN.
MODELS CONTINUE TO BUILD AN UPPER RIDGE OVER THE REGION FROM SUN
THROUGH THE REST OF NEXT WEEK. RAIN CHANCES WILL BE MINIMAL...BUT
COULD SEE SOME CONVECTION WED OR THU IF SHORTWAVE ENERGY CAN ROUND
THE TOP OF THE RIDGE...BUT CHANCES ARE LOW. THE AIRMASS WILL BE ON
THE RISE...HOVERING AROUND 20C FROM LATE MON THROUGH THE REST OF THE
WEEK. THIS RESULTS IN TEMPS BEING 10 OR MORE DEGREES ABOVE NORMAL
FROM MON ON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 125 PM EDT THU AUG 27 2015
RELATIVELY DRY AIR MASS OVER THE AREA SHOULD ENSURE VFR CONDITIONS
CONTINUE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT THU AUG 27 2015
A GENERALLY WEAK PRES GRADIENT WILL DOMINATE THE UPPER LAKES INTO
EARLY NEXT WEEK. ON MOST DAYS...WINDS WILL BE UNDER 15KT...BUT THERE
WILL BE SOME PERIODS WHERE GUSTS WILL GET INTO THE 15-20KT RANGE.
LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE WEEKEND WITH HIGH
PRES RIDGE MORE FIRMLY IN CONTROL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 AM EDT THU AUG 27 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 350 PM EDT WED AUG 26 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THAT THE MID LEVEL LOW
THAT HAS PLAGUED UPPER MI FOR THE LAST 2 DAYS WITH UNSEASONABLY COOL
WEATHER IS NOW CENTERED SE OF JAMES BAY AND IS CONTINUING TO DRIFT
E. UPSTREAM...A RIDGE EXTENDS FROM THE SRN ROCKIES INTO
SASKATCHEWAN/MANITOBA/NRN ONTARIO. VIS SATELLITE IMAGERY SHOWS THE
BACK EDGE OF THE LOW CLOUDS ASSOCIATED WITH LOW AND DEPARTING
THERMAL TROF RUNNING FROM ROUGHLY COPPER HARBOR TO MARQUETTE TO IRON
MTN. TO THE W...ELEVATED SMOKE LAYER FROM THE PACIFIC NW FOREST
FIRES IS ONCE AGAIN SPREADING ACROSS THE NRN PLAINS WITH LEADING
EDGE APPROACHING WRN LAKE SUPERIOR/FAR NW WI.
SHORT TERM PORTION OF THE FCST WILL BE QUIET AS SFC HIGH PRES RIDGE
MOVES ACROSS THE UPPER LAKES TONIGHT AND CONTINUES TO DRIFT EASTWARD
ON THU. MAIN FCST ISSUES WILL REVOLVE AROUND CLOUDS/TEMPS AND
FROST/FOG POTENTIAL TONIGHT. EXPECT CLOUDS TO CONTINUE CLEARING OUT
FROM NW TO SE OVER THE NEXT SEVERAL HRS. HOWEVER...THERE IS
CERTAINLY CONCERN THAT CLEARING MAY NOT PROGRESS FAR ENOUGH SE
BEFORE LOW-LEVEL WINDS VEER AND EITHER HOLD CLOUDS IN OVER THE E OR
BRING THEM BACK. FOR NOW...THE PLAN IS FOR DAYTIME HEATING TO
CONTINUE MIXING OUT THE MOISTURE FROM THE W AND AID THE CURRENT SE
CLEARING TREND...HELPING IT PROGRESS FAR ENOUGH THAT CLOUDS WILL
STAY E OF THE FCST AREA TONIGHT. IF CLOUDS DO NOT CLEAR OUT OF THE
ERN FCST AREA BY SUNSET...SKIES PROBABLY WON`T CLEAR TONIGHT.
OTHERWISE...AS SFC HIGH PRES SLOWLY MOVES ACROSS THE FCST AREA
TONIGHT...STAGE WILL BE SET FOR A COOL NIGHT UNDER CLEAR SKIES/CALM
WIND AND DRY AIR MASS WITH PRECIPITABLE AROUND ONE-HALF INCH. LEANED
FCST SIGNIFICANTLY TOWARD BOTH BIAS CORRECTED CANADIAN MODELS FOR
MINS DUE TO THEIR USUAL BETTER PERFORMANCE IN RADIATIONAL COOLING
SITUATIONS. EXPECT THE NORMAL COLD AREAS IN THE INTERIOR TO FALL
INTO THE UPPER 30S WITH TRADITIONAL COLD SPOTS DOWN INTO THE MID
30S. WILL INCLUDE PATCHY FROST IN THE FCST. TYPICAL FOR THIS TIME OF
YEAR UNDER RADIATIONAL COOLING CONDITIONS...EXPECT SOME FOG TO
DEVELOP AS WELL NEAR RIVERS/STREAMS/LAKES/SWAMPY AREAS.
RETURN FLOW WILL BEGIN ON THU AS THE SFC HIGH PRES RIDGE CONTINUES
TO DRIFT E. WITH LINGERING DRY AIR MASS...EXPECT ONLY SOME HIGH
CLOUDS...THOUGH SKY WILL LIKELY BE HAZY WITH ELEVATED SMOKE LAYER
OVER THE UPPER LAKES. WITH MORNING 850MB TEMPS OF 10-12C AND RISING
1-2C DURING THE DAY...EXPECT AFTN MAX TEMPS MOSTLY IN THE LOWER TO
MIDDLE 70S AWAY FROM ANY LAKE MODERATION.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 453 PM EDT WED AUG 26 2015
THE MODELS WERE IN OVERALL AGREEMENT WITH THE PATTERN TRANSITION
FROM ZONAL FLOW TO A MORE AMPLIFIED PATTERN NEXT WEEK WITH A TROUGH
OVER THE NW CONUS AND A RIDGE OVER THE CNTRL AND EAST.
THURSDAY NIGHT...AS THE SFC RIDGE SLIDES OFF TO THE EAST AND 850-700
MB WAA DEVELOPS...EXPECT SOME INCREASE IN MID CLOUDS ACROSS UPPER
MICHIGAN. THIS SHOULD HELP KEEP OVERNIGHT LOWS IN THE MID 50S INLAND
TO AROUND 60 NEAR LAKE SUPERIOR WHERE DOWNSLOPE FLOW PREVAILS.
FRI THROUGH SAT...THERE IS STILL PLENTY OF UNCERTAINTY WITH THE
PATH/TIMING OF THE SHORTWAVE EMERGING FROM THE PLAINS. THE
GFS...GEM AND ESPECIALLY THE ECMWF HAVE TRENDED FARTHER NORTH WITH
THE SYSTEM WHICH COULD REMAIN JUST SOUTH OF THE CWA OR BRING RAIN TO
MOST OF THE AREA. THE FCST REFLECTS THESE TRENDS AND REMAINING
UNCERTAINTY WITH INCREASING POPS THAT REMAIN IN THE CHANCE CATEGORY.
THE BEST CHANCE FOR RAIN WOULD ARRIVE MAINLY FRI NIGHT AND LINGER
OVER THE ERN CWA AT LEAST THROUGH SAT MORNING. THERE MAY ENOUGH
HEATING/INSTABILITY FRI FOR AT LEAST A MENTION OF TSRA...BUT MOST OF
THE PCPN ASSOCIATED WITH THE SHRTWV WILL NOT HAVE TS...PER GFS/ECMWF
INSTABILITY PROGS.
SAT NIGHT THROUGH WED...THE BUILDING RIDGE WILL BRING WARMER
CONDITIONS WITH MAINLY DRY CONDITIONS. EXPECT THE FRONTAL BOUNDARY
TO REMAIN FAR ENOUGH WEST TO MINIMIZE SHRA/TSRA CHANCES. HIGHS WILL
CLIMB WELL ABOVE NORMAL WITH HIGHS WELL INTO THE 80S FROM MON
THROUGH WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 131 AM EDT THU AUG 27 2015
VFR CONDITIONS TO REMAIN THE RULE AT KIWD AND KCMX...WHILE THERE IS
A POSSIBILITY THAT KSAW WILL SEE MVFR VISIBILITIES OVERNIGHT AS FOG
DEVELOPS WITH CLEAR SKIES AND LIGHT WINDS OVER THE REGION. CANNOT
COMPLETELY RULE OUT FOG AT KIWD AS VSBYS HAVE DROPPED OVER NRN WI
LATE THIS EVENING BUT CONFIDENCE IS NOT HIGH ENOUGH THERE TO PUT IT
IN THE FORECAST. IF FOG DOES DEVELOP THERE...SHOULD ONLY DROP VSBYS
TO MVFR. ANY FOG THAT DOES DEVELOP WILL QUICKLY BURN OFF AFTER
SUNRISE WITH VFR CONDITIONS THROUGH THE FORECAST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 PM EDT WED AUG 26 2015
WITH SFC HIGH PRES OVER THE UPPER GREAT LAKES...WINDS WILL BE LESS
THAN 15KT ACROSS LAKE SUPERIOR TONIGHT. ALTHOUGH THE HIGH DRIFTS E
ON THU...WINDS WILL REMAIN UNDER 15KT THOUGH LOCALLY SLIGHTLY HIGHER
E TO SE WINDS ARE POSSIBLE IN THE AFTN IN THE VCNTY OF THE HURON
ISLANDS. WINDS SHOULD REMAIN UNDER 20KT THRU THE WEEKEND...BUT THERE
MAY BE SOME PERIODS WHERE WIND GUSTS EXCEED 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...RJT
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
117 PM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU AUG 27 2015
SHORT TERM CONCERNS ARE SHOWER THREAT RIDING EAST THIS MORNING.
THEN DEVELOPMENT OF CLOSED CIRCULATION AND HEAVY RAIN THREAT OVER
THE SOUTHERN CWA OVERNIGHT.
SPC MESOANALYSIS HAS A NARROW BAND OF MID LEVEL FRONTOGENESIS OVER
SOUTHERN NORTH DAKOTA THIS MORNING. AREA OF MID CLOUDS/SHOWERS AND
THUNDER THE FARTHER SOUTH IN SOUTH DAKOTA. MCS OVER SOUTH DAKOTA
SHOULD CONTINUE TO RIDE EAST/SOUTHEAST THIS MORNING AND GRADUALLY
DECAY. THERE WILL BE A LOT OF CLOUDS ASSOCIATED WITH THIS FEATURE
ALONG WITH THE FRONT BAND THAT MOVES ACROSS. JET STREAK RIDING
NORTH OF THE SOUTH DAKOTA COMPLEX SHOULD DRIVE THIS MID CLOUD
LAYER /FORCING EAST DURING THE MORNING. THE TREND OF THE HRRR AND
HRRR-CR BRING THIS AREA EAST TO THE METRO BY EARLY AFTERNOON. HAD
TO INCLUDE SOME CHANCE POPS FOR THIS THREAT. NEIGHBORHOOD POPS
FROM THE HIRES CAMS ARE JUST NOW BEGINNING PICK UP ON THIS. DONT
ANTICIPATE ANY SIGNIFICANT THUNDER THREAT UNTIL LATE THIS
AFTERNOON TO THE SOUTHWEST WHERE BETTER INSTABILITY IF FORECAST.
THAT ALL DEPENDS ON HOW MUCH HEATING WILL OCCUR HOWEVER. HIGH
TEMPERATURE FORECAST ALSO TRICKY...WITH THE THICKER CLOUD COVER
POSSIBLE AT LEAST THROUGH THE MORNING. MID/UPPER 70S LOOK LIKELY.
THE DETERMINISTIC MODELS ARE IN FAIR AGREEMENT WITH PLACEMENT OF
HEAVIER RAIN ACROSS SOUTHERN QUARTER OF THE STATE OVERNIGHT INTO
FRIDAY. THE ECMWF IS SLOWER WITH MOVEMENT OF THE TROUGH HOWEVER.
AT THE MOMENT HAVE ABOUT 0.80 TO 1.25 INCHES QPF FORECAST FOR THE
OVERNIGHT OVER SOUTH CENTRAL MINNESOTA. THE HIRES CAM SOLUTIONS
WERE MOVING THE HEAVIER QPF SOUTH INTO IOWA. THE 03Z SREF WAS
STILL WAS FOCUSING HEAVIER RAIN ACROSS SOUTH CENTRAL MN SO WE WILL
CONTINUE THE HIGHER QPF THIS REGION FOR NOW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU AUG 27 2015
THE LONG TERM PERIOD STARTS OUT ON AN ACTIVE NOTE...AND THEN
FEATURES OVERALL DRY WEATHER WITH MODERATING TEMPERATURES NEXT
WEEK.
THE NORTHERN EXTENT OF /HEAVY/ RAINFALL CONTINUES TO BE THE
PRIMARY CONCERN FOR FRIDAY...GIVEN MODELS HAVE FLUCTUATED NORTH
AND SOUTH WITH THE TRACK OF THE SURFACE LOW AND ASSOCIATED
PRECIPITATION FOR SEVERAL DAYS. THE ECMWF HAS BEEN THE FARTHEST
NORTH AND MOST PERSISTENT WITH RAIN SPREADING INTO CENTRAL
MINNESOTA ON FRIDAY MORNING...AND THE OTHER MODELS HAVE TRENDED
THAT WAY. HAVE THEREFORE MAINTAINED CATEGORICAL POPS AS FAR NORTH
AS THE INTERSTATE 94 CORRIDOR /INCLUDING THE TWIN CITIES METRO AND
EAU CLAIRE/. THE INTERSTATE 90 CORRIDOR STILL LOOKS TO BEAR THE
BRUNT OF THE HEAVY RAINFALL...WHERE ONE TO THREE INCH AMOUNTS
APPEAR POSSIBLE AS PWATS INCREASE TO CLIMATOLOGICAL MAXIMUMS /1.75
INCHES/ AND COMBINE WITH A HEALTHY LLVL JET OF 45KTS.
THE ECMWF SOLUTION ALSO LINGERS PRECIPITATION WELL INTO FRIDAY
AFTERNOON ALONG AND EAST OF THE INTERSTATE 35 CORRIDOR...GIVEN IT
IS MUCH STRONGER AND SLOWER WITH THE LOW. LEANED TOWARD A SLIGHTLY MORE
OPTIMISTIC SCENARIO CLOSER TO WHAT THE 27.00Z GFS
INDICATES...BUT IT STILL LOOKS LIKE A SOGGY DAY FROM SOUTH/EAST
CENTRAL MN INTO CENTRAL WI. FRIDAY HIGH TEMPERATURES WILL BE
IMPACTED NOTABLY WITH THE ANTICIPATED CLOUDS/PRECIP...WITH MID 60S
/SOUTHEAST/ TO MID 70S /NORTHWEST/ EXPECTED.
REGARDLESS OF WHAT MODEL IS SELECTED...WE SHOULD CLEAR OUT FOR
SATURDAY...WITH LIGHT WINDS AND MILD TEMPS IN THE MID 70S TO LOWER
80S.
THE REMAINDER OF THE LONG TERM FORECAST IS MARKED BY MODERATING
TEMPERATURES AS LLVL TEMPS GRADUALLY RISE. SHOULD SEE MID/UPPER
80S FOR MOST OF THE UPCOMING WEEK. A WASHED OUT FRONT WILL HANG
OUT NEAR THE AREA MID TO LATE NEXT WEEK...BUT TEMPS ALOFT ARE
LIKELY TOO WARM FOR CONVECTIVE DEVELOPMENT GIVEN THE LACK OF
FORCING. HAVE THEREFORE KEPT THE FORECAST MOSTLY DRY FOR NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1250 PM CDT THU AUG 27 2015
THE FIRST 12 HOURS OF THE FORECAST LOOK MAINLY VFR...WITH THE MOST
INTERESTING TIME PERIOD FROM MIDNIGHT AND BEYOND. FOR THE
REMAINDER OF TODAY...EXPECTING HIGH LEVEL CLOUDINESS TO CONTINUE
STREAMING IN...WITH MID LEVEL CLOUDINESS AND SHOWERS PUSHING INTO
SOUTHWESTERN MN. RWF WILL BE THE MOST VULNERABLE TO PRECIP THIS
AFTERNOON. THE SURFACE LOW IS EXPECTED TO REMAIN SOUTH OF THE MN
BORDER...BUT GUIDANCE STILL INDICATES WIDESPREAD MVFR POSSIBLE.
PUSHED BACK THE ONSET SLIGHTLY...MAINLY VERY LATE TONIGHT THROUGH
THE MORNING ON FRIDAY. IN FACT...AT THIS POINT IT LOOKS LIKE THE
CIGS MAY BE LOWEST TOMORROW AFTER DAYBREAK AND WE MAY CARRY MVFR
UNTIL AT LEAST 18Z...POTENTIALLY ALL DAY. SOME GUIDANCE INDICATES
IFR CIGS POSSIBLE...BUT NOT READY TO BITE ON THAT AT THIS TIME
WITH THE LOW BEING SO FAR SOUTH.
KMSP...MOST OF THE PRECIP WILL STAY SOUTH OF MSP...BUT STILL
EXPECT THE POSSIBILITY OF SOME LIGHT RAIN AT MSP EARLY TOMORROW.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS SE 5-10 KTS.
SUN...VFR. WINDS S 5-10 KTS.
MON...VFR. WINDS S 5-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
554 AM CDT THU AUG 27 2015
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU AUG 27 2015
SHORT TERM CONCERNS ARE SHOWER THREAT RIDING EAST THIS MORNING.
THEN DEVELOPMENT OF CLOSED CIRCULATION AND HEAVY RAIN THREAT OVER
THE SOUTHERN CWA OVERNIGHT.
SPC MESOANALYSIS HAS A NARROW BAND OF MID LEVEL FRONTOGENESEIS OVER
SOUTHERN NORTH DAKOTA THIS MORNING. AREA OF MID CLOUDS/SHOWERS AND
THUNDER THE FARTHER SOUTH IN SOUTH DAKOTA. MCS OVER SOUTH DAKOTA
SHOULD CONTINUE TO RIDE EAST/SOUTHEAST THIS MORNING AND GRADUALLY
DECAY. THERE WILL BE A LOT OF CLOUDS ASSOCIATED WITH THIS FEATURE
ALONG WITH THE FRONT BAND THAT MOVES ACROSS. JET STREAK RIDING NORTH
OF THE SOUTH DAKOTA COMPLEX SHOULD DRIVE THIS MID CLOUD LAYER
/FORCING EAST DURING THE MORNING. THE TREND OF THE HRRR AND HRRR-CR
BRING THIS AREA EAST TO THE METRO BY EARLY AFTERNOON. HAD TO INCLUDE
SOME CHANCE POPS FOR THIS THREAT. NEIGHBORHOOD POPS FROM THE HIRES
CAMS ARE JUST NOW BEGINNING PICK UP ON THIS. DONT ANTICIPATE ANY
SIGNIFICANT THUNDER THREAT UNTIL LATE THIS AFTERNOON TO THE
SOUTHWEST WHERE BETTER INSTABILITY IF FORECAST. THAT ALL DEPENDS ON
HOW MUCH HEATING WILL OCCUR HOWEVER. HIGH TEMPERATURE FORECAST ALSO
TRICKY...WITH THE THICKER CLOUD COVER POSSIBLE AT LEAST THROUGH THE
MORNING. MID/UPPER 70S LOOK LIKELY.
THE DETERMINISITIC MODELS ARE IN FAIR AGREEMENT WITH PLACEMENT OF
HEAVIER RAIN ACROSS SOUTHERN QUARTER OF THE STATE OVERNIGHT INTO
FRIDAY. THE ECMWF IS SLOWER WITH MOVEMENT OF THE TROUGH HOWEVER. AT
THE MOMENT HAVE ABOUT 0.80 TO 1.25 INCHES QPF FORECAST FOR THE
OVERNIGHT OVER SOUTH CENTRAL MINNESOTA. THE HIRES CAM SOLUTIONS
WERE MOVING THE HEAVIER QPF SOUTH INTO IOWA. THE 03Z SREF WAS STILL
WAS FOCUSING HEAVIER RAIN ACROSS SOUTH CENTRAL MN SO WE WILL
CONTINUE THE HIGHER QPF THIS REGION FOR NOW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU AUG 27 2015
THE LONG TERM PERIOD STARTS OUT ON AN ACTIVE NOTE...AND THEN
FEATURES OVERALL DRY WEATHER WITH MODERATING TEMPERATURES NEXT
WEEK.
THE NORTHERN EXTENT OF /HEAVY/ RAINFALL CONTINUES TO BE THE
PRIMARY CONCERN FOR FRIDAY...GIVEN MODELS HAVE FLUCTUATED NORTH
AND SOUTH WITH THE TRACK OF THE SURFACE LOW AND ASSOCIATED
PRECIPITATION FOR SEVERAL DAYS. THE ECMWF HAS BEEN THE FARTHEST
NORTH AND MOST PERSISTENT WITH RAIN SPREADING INTO CENTRAL
MINNESOTA ON FRIDAY MORNING...AND THE OTHER MODELS HAVE TRENDED
THAT WAY. HAVE THEREFORE MAINTAINED CATEGORICAL POPS AS FAR NORTH
AS THE INTERSTATE 94 CORRIDOR /INCLUDING THE TWIN CITIES METRO AND
EAU CLAIRE/. THE INTERSTATE 90 CORRIDOR STILL LOOKS TO BEAR THE
BRUNT OF THE HEAVY RAINFALL...WHERE ONE TO THREE INCH AMOUNTS
APPEAR POSSIBLE AS PWATS INCREASE TO CLIMATOLOGICAL MAXIMUMS /1.75
INCHES/ AND COMBINE WITH A HEALTHY LLVL JET OF 45KTS.
THE ECMWF SOLUTION ALSO LINGERS PRECIPITATION WELL INTO FRIDAY
AFTERNOON ALONG AND EAST OF THE INTERSTATE 35 CORRIDOR...GIVEN IT
IS MUCH STRONGER AND SLOWER WITH THE LOW. LEANED TOWARD A SLIGHTLY MORE
OPTIMISTIC SCENARIO CLOSER TO WHAT THE 27.00Z GFS
INDICATES...BUT IT STILL LOOKS LIKE A SOGGY DAY FROM SOUTH/EAST
CENTRAL MN INTO CENTRAL WI. FRIDAY HIGH TEMPERATURES WILL BE
IMPACTED NOTABLY WITH THE ANTICIPATED CLOUDS/PRECIP...WITH MID 60S
/SOUTHEAST/ TO MID 70S /NORTHWEST/ EXPECTED.
REGARDLESS OF WHAT MODEL IS SELECTED...WE SHOULD CLEAR OUT FOR
SATURDAY...WITH LIGHT WINDS AND MILD TEMPS IN THE MID 70S TO LOWER
80S.
THE REMAINDER OF THE LONG TERM FORECAST IS MARKED BY MODERATING
TEMPERATURES AS LLVL TEMPS GRADUALLY RISE. SHOULD SEE MID/UPPER
80S FOR MOST OF THE UPCOMING WEEK. A WASHED OUT FRONT WILL HANG
OUT NEAR THE AREA MID TO LATE NEXT WEEK...BUT TEMPS ALOFT ARE
LIKELY TOO WARM FOR CONVECTIVE DEVELOPMENT GIVEN THE LACK OF
FORCING. HAVE THEREFORE KEPT THE FORECAST MOSTLY DRY FOR NEXT
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 555 AM CDT THU AUG 27 2015
LOW CONFIDENCE ON OVERALL TRENDS IN TIMING OF -SHRA INTO THE DAY.
SOME CHANCE OF ACTIVITY MOVING EAST/SOUTHEAST ACROSS MN PORTION
OF THE FA DURING THE MORNING PER TREND OF THE RAP/HRRR. SHOULD
REMAIN VFR WITH SLOWLY LOWERING MID CLOUD DECK TO MVFR INTO THE
EVENING OUT WEST...SPREADING EAST AFTER 06Z. IT SHOULD REMAIN VFR
INTO MOST OF WEST CENTRAL WI INTO TONIGHT. MORE WIDESPREAD RAIN
WITH ISOLD THUNDER POSSIBLE DEVELOPING SOUTHWEST THIS EVENING AND
ACROSS SOUTHERN MN INTO FRIDAY MORNING. SHOULD SEE IT MOVE INTO
WISCONSIN MAINLY AFTER 06Z. BEST THUNDER THREAT AROUND KRWF LATE
AFTERNOON/EVENING. LOWER IFR CIGS LIKELY DEVELOPING AFTER 08Z
INTO THE SOUTHWEST TOWARD EASTERN MN AFTER 12Z FRI.
KMSP...
VFR CONDITIONS EXPECTED THROUGH AT LEAST 06Z FRI. WILL SEE A
CHANCE OF -SHRA MOVING INTO THE AREA AFTER 18Z BUT IT SHOULD
REMAIN LIGHT AND WEAKEN AS IT MOVES INTO THE AREA. THEN MORE
WIDESPREAD -SHRA/RA BR EXPECTED WITH MVFR CIGS DEVELOPING AFTER
09Z LATE. SOME THREAT OF THUNDER...BUT BELIEVE THAT WILL BE
LIMITED TO SOUTHWEST MN AT THIS TIME. LIGHT SOUTHEAST WIND INTO
THE NIGHT GENERALLY 10KTS OR LESS.
/OUTLOOK FOR KMSP/
FRI AFTN...VFR. CHC MVFR SHRA. WINDS SE 7-15 KTS.
SAT...VFR. WINDS SE 5-10 KTS.
SUN...VFR. WINDS S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
354 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU AUG 27 2015
SHORT TERM CONCERNS ARE SHOWER THREAT RIDING EAST THIS MORNING.
THEN DEVELOPMENT OF CLOSED CIRCULATION AND HEAVY RAIN THREAT OVER
THE SOUTHERN CWA OVERNIGHT.
SPC MESOANALYSIS HAS A NARROW BAND OF MID LEVEL FRONTOGENESEIS OVER
SOUTHERN NORTH DAKOTA THIS MORNING. AREA OF MID CLOUDS/SHOWERS AND
THUNDER THE FARTHER SOUTH IN SOUTH DAKOTA. MCS OVER SOUTH DAKOTA
SHOULD CONTINUE TO RIDE EAST/SOUTHEAST THIS MORNING AND GRADUALLY
DECAY. THERE WILL BE A LOT OF CLOUDS ASSOCIATED WITH THIS FEATURE
ALONG WITH THE FRONT BAND THAT MOVES ACROSS. JET STREAK RIDING NORTH
OF THE SOUTH DAKOTA COMPLEX SHOULD DRIVE THIS MID CLOUD LAYER
/FORCING EAST DURING THE MORNING. THE TREND OF THE HRRR AND HRRR-CR
BRING THIS AREA EAST TO THE METRO BY EARLY AFTERNOON. HAD TO INCLUDE
SOME CHANCE POPS FOR THIS THREAT. NEIGHBORHOOD POPS FROM THE HIRES
CAMS ARE JUST NOW BEGINNING PICK UP ON THIS. DONT ANTICIPATE ANY
SIGNIFICANT THUNDER THREAT UNTIL LATE THIS AFTERNOON TO THE
SOUTHWEST WHERE BETTER INSTABILITY IF FORECAST. THAT ALL DEPENDS ON
HOW MUCH HEATING WILL OCCUR HOWEVER. HIGH TEMPERATURE FORECAST ALSO
TRICKY...WITH THE THICKER CLOUD COVER POSSIBLE AT LEAST THROUGH THE
MORNING. MID/UPPER 70S LOOK LIKELY.
THE DETERMINISITIC MODELS ARE IN FAIR AGREEMENT WITH PLACEMENT OF
HEAVIER RAIN ACROSS SOUTHERN QUARTER OF THE STATE OVERNIGHT INTO
FRIDAY. THE ECMWF IS SLOWER WITH MOVEMENT OF THE TROUGH HOWEVER. AT
THE MOMENT HAVE ABOUT 0.80 TO 1.25 INCHES QPF FORECAST FOR THE
OVERNIGHT OVER SOUTH CENTRAL MINNESOTA. THE HIRES CAM SOLUTIONS
WERE MOVING THE HEAVIER QPF SOUTH INTO IOWA. THE 03Z SREF WAS STILL
WAS FOCUSING HEAVIER RAIN ACROSS SOUTH CENTRAL MN SO WE WILL
CONTINUE THE HIGHER QPF THIS REGION FOR NOW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU AUG 27 2015
THE LONG TERM PERIOD STARTS OUT ON AN ACTIVE NOTE...AND THEN
FEATURES OVERALL DRY WEATHER WITH MODERATING TEMPERATURES NEXT
WEEK.
THE NORTHERN EXTENT OF /HEAVY/ RAINFALL CONTINUES TO BE THE
PRIMARY CONCERN FOR FRIDAY...GIVEN MODELS HAVE FLUCTUATED NORTH
AND SOUTH WITH THE TRACK OF THE SURFACE LOW AND ASSOCIATED
PRECIPITATION FOR SEVERAL DAYS. THE ECMWF HAS BEEN THE FARTHEST
NORTH AND MOST PERSISTENT WITH RAIN SPREADING INTO CENTRAL
MINNESOTA ON FRIDAY MORNING...AND THE OTHER MODELS HAVE TRENDED
THAT WAY. HAVE THEREFORE MAINTAINED CATEGORICAL POPS AS FAR NORTH
AS THE INTERSTATE 94 CORRIDOR /INCLUDING THE TWIN CITIES METRO AND
EAU CLAIRE/. THE INTERSTATE 90 CORRIDOR STILL LOOKS TO BEAR THE
BRUNT OF THE HEAVY RAINFALL...WHERE ONE TO THREE INCH AMOUNTS
APPEAR POSSIBLE AS PWATS INCREASE TO CLIMATOLOGICAL MAXIMUMS /1.75
INCHES/ AND COMBINE WITH A HEALTHY LLVL JET OF 45KTS.
THE ECMWF SOLUTION ALSO LINGERS PRECIPITATION WELL INTO FRIDAY
AFTERNOON ALONG AND EAST OF THE INTERSTATE 35 CORRIDOR...GIVEN IT
IS MUCH STRONGER AND SLOWER WITH THE LOW. LEANED TOWARD A SLIGHTLY MORE
OPTIMISTIC SCENARIO CLOSER TO WHAT THE 27.00Z GFS
INDICATES...BUT IT STILL LOOKS LIKE A SOGGY DAY FROM SOUTH/EAST
CENTRAL MN INTO CENTRAL WI. FRIDAY HIGH TEMPERATURES WILL BE
IMPACTED NOTABLY WITH THE ANTICIPATED CLOUDS/PRECIP...WITH MID 60S
/SOUTHEAST/ TO MID 70S /NORTHWEST/ EXPECTED.
REGARDLESS OF WHAT MODEL IS SELECTED...WE SHOULD CLEAR OUT FOR
SATURDAY...WITH LIGHT WINDS AND MILD TEMPS IN THE MID 70S TO LOWER
80S.
THE REMAINDER OF THE LONG TERM FORECAST IS MARKED BY MODERATING
TEMPERATURES AS LLVL TEMPS GRADUALLY RISE. SHOULD SEE MID/UPPER
80S FOR MOST OF THE UPCOMING WEEK. A WASHED OUT FRONT WILL HANG
OUT NEAR THE AREA MID TO LATE NEXT WEEK...BUT TEMPS ALOFT ARE
LIKELY TOO WARM FOR CONVECTIVE DEVELOPMENT GIVEN THE LACK OF
FORCING. HAVE THEREFORE KEPT THE FORECAST MOSTLY DRY FOR NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU AUG 27 2015
VFR CONDITIONS EXPECTED THROUGH MN PORTION OF THE FA WITH AREAS OF
LIFR/IFR FOG OVER WEST CENTRAL WI THROUGH 13Z THU.
SOME MID/HIGH LEVEL CLOUDS SPREADING EAST/SOUTHEAST ACROSS MN
OVERNIGHT INTO THURSDAY. SOME THREAT OF -SHRA INTO THU MORNING
OVER THE WEST...BUT EXPECT THAT TO GRADUALLY DRY UP DURING THE
LATE MORNING. THEN LOWERING CEILINGS INTO THE LATE
AFTERNOON/EVENING WITH APPROACH OF NEXT TROUGH. SOME -TSRA THREAT
MAINLY TO THE SOUTHWEST/KRWF REGION INTO THE EVENING BEFORE MORE
WIDESPREAD -SHRA/RA DEVELOPS OVERNIGHT ACROSS THE SOUTHERN THIRD
OF MN.
KMSP...
VFR CONDITIONS EXPECTED THROUGH AT LEAST 06Z FRI. THEN MORE
WIDESPREAD -SHRA/RA BR EXPECTED INTO THE AREA WITH MVFR CIGS
DEVELOPING LATE. SOME THREAT OF THUNDER...BUT BELIEVE THAT WILL
BE LIMITED TO SOUTHWEST MN AT THIS TIME. LIGHT SOUTHEAST WIND
INTO THE NIGHT GENERALLY 10KTS OR LESS.
/OUTLOOK FOR KMSP/
FRI...VFR. CHC MVFR SHRA/TSRA. WINDS SE 7-15 KTS.
SAT...VFR. WINDS SE 5-10 KTS.
SUN...VFR. WINDS S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS DULUTH MN
307 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 230 AM CDT THU AUG 27 2015
MAIN CONCERNS IN THE SHORT TERM REMAIN FOCUSED AROUND THE COOL
TEMPERATURES THIS MORNING ALONG WITH PATCHY FOG BEFORE 9 AM. WILL
ALSO HIGHLIGHT THE INCOMING POTENTIAL FOR SHOWERS AND ISOLATED
STORMS LATE TONIGHT AND INTO FRIDAY...MAINLY OVER PORTIONS OF NW
WI FRI MORNING...AND ACROSS THE NE MN FRIDAY AFTERNOON.
SURFACE RIDGE AND WEAK INFLUENCE FROM A MID-LEVEL HIGH WILL STILL
BE PRESENT ACROSS THE ERN PORTIONS OF THE NORTHLAND TODAY...AND
ALLOW THE AREA TO REMAIN DRY THROUGH THE DAY. THE CLEAR SKIES THIS
MORNING...COMBINED WITH CALM WINDS AND A WEAK INVERSION ALOFT HAVE
ALLOWED FOR PATCHY FOG TO DEVELOP. LOWER VISIBILITIES HAVE BEEN
VERY ISOLATED THIS MORNING...BUT LESS THAN 1 MILE IN SOME
LOCATIONS. TEMPERATURES THIS MORNING HAVE BOTTOMED OUT MOSTLY IN
THE UPPER 30S AND 40S...WITH SLIGHTLY WARMER CONDITIONS TO THE
EAST INTO THE LOWER 50S.
MUCH OF THE REGION WILL BE UNDER THE INFLUENCE OF A WARM AIR
ADVECTION REGIME TODAY WITH A MODEST SOUTHERLY FLOW DEVELOPING.
TEMPERATURES WILL WARM INTO THE LOWER TO MID 70S OVER THE ENTIRE
REGION.
TONIGHT AN AREA OF LOW PRESSURE WILL TRACK FROM EASTERN NEBRASKA
INTO FAR SRN MN/N-CENTRAL IA. AN AREA OF SHOWERS AND STORMS
ASSOCIATED WITH THIS LOW WILL MOVE FROM ERN SD ACROSS SRN MN...AND
SLOWLY SPREAD E/NEWD FRIDAY MORNING. THE NWD EXTENT OF THE PRECIP
SHIELD WILL BE THE CHALLENGE WITH THIS SYSTEM...AND MODEL
AGREEMENT HAS BEEN NOT THE BEST OVER THE PAST COUPLE DAYS.
STILL...EXPECTING THE SHOWERS AND ISOLATED STORMS TO REMAIN SOUTH
OF THE TWIN PORTS AND CONFINED TO AREAS OF NW WI DURING THE
MORNING HOURS. A SECONDARY FRONT WILL MOVE IN FROM THE NW IN THE
AFTERNOON AND COMBINE WITH A SLIGHTLY UNSTABLE MIXED LAYER TO
PRODUCE SCATTERED SHOWERS AND ISOLATED WEAK STORMS ACROSS NERN
MN...NORTH OF HIGHWAY 2. RAINFALL AMTS IN THE MORNING COULD REACH
A QUARTER TO HALF AN INCH IN N-CENTRAL WI...WITH LESSER AMTS TO
THE NORTH AND WEST. AREAS OF NE MN WILL ONLY SEE AROUND A TENTH OF
AN INCH OR SO.
TEMPERATURES TONIGHT WILL ONLY FALL INTO THE 50S...AND RISE DURING
THE DAY FRIDAY INTO THE MID TO UPPER 70S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 AM CDT THU AUG 27 2015
THE 00Z ECMWF MAINTAINS THE NORTHERLY TRACK OF ITS SFC LOW COMPARED
TO THE OTHER MODELS FOR FRIDAY NIGHT. MEANWHILE...IMPULSES EMBEDDED
IN NW FLOW ALOFT OVER THE FORECAST AREA WILL GENERATE SOME
THUNDERSTORMS FRIDAY NIGHT AND SATURDAY MORNING OVER THE NORTHERN
HALF OF THE AREA. BY SATURDAY AFTERNOON...UPPER LEVEL AND SFC
RIDGING WILL MOVE INTO THE REGION. THIS RIDGING WILL PERSIST THROUGH
SUNDAY. SUNDAY NIGHT FINDS A WAA/RETURN FLOW PATTERN BECOMING
ESTABLISHED IN THE LOWER 5K FT WHILE RIDGING PREVAILS ALOFT. THE
ECMWF IS THE FASTEST WITH THE ONSET OF RAIN INTO KOOCHICHING COUNTY
SUNDAY NIGHT...WHILE THE OTHER MODELS ARE DRY. A BLEND RESULTED IN
SMALL POPS OVER KOOCHICHING COUNTY. WITH THE INSTABILITY AXIS WEST
OF THE AREA...LEFT OUT THE MENTION OF THUNDER. THE UPPER RIDGING
MOVES OFF TO THE EAST ON MONDAY ALLOWING FOR A FAST SW FLOW OVER THE
REGION ON MONDAY. THERMAL PROFILE DIFFERENCES ARE QUITE LARGE AND SO
IS THE HANDLING OF QPF. USED THE BLENDED APPROACH HERE FOR POPS AND
TEMPS. THE SW FLOW REMAINS OVER THE AREA THROUGH WEDNESDAY DUE TO A
STATIONARY LONG WAVE TROF OVER THE EAST COAST...WHICH ALSO BECOMES
TANGLED WITH TROPICAL SYSTEM ERIKA. EMBEDDED IMPULSES IN THIS SW
FLOW WILL TRACK OVER THE REGION WARRANTING A POP MENTION.
TEMPERATURES WILL WARM BACK UP TO MIDDLE SUMMER VALUES WITH MAX
TEMPS IN THE 80S COMMON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 102 AM CDT THU AUG 27 2015
HIGH PRESSURE IS CURRENTLY LOCATED OVER THE CENTRAL GREAT LAKES.
THE HIGH WILL MOVE EASTWARDS INTO THE EASTERN GREAT LAKES BY THE
END OF THE FORECAST CYCLE...WHILE A DEVELOPING LOW MOVES FROM THE
CENTRAL PLAINS INTO SOUTHEASTERN SOUTH DAKOTA/EASTERN NEBRASKA.
DUE TO HIGH PRESSURE...SKIES HAVE CLEARED AND WINDS HAVE BECOME
LIGHT. AS A RESULT PATCHY FOG HAS DEVELOPED. EXPECTING WINDS TO
REMAIN OUT OF THE SOUTH/SOUTHEAST AT KINL/KBRD...AND WINDS SHOULD
BE HIGH ENOUGH TO KEEP FOG FROM FORMING. MOST CONFIDENT IN FOG
FORMATION AT KHIB AND KHYR DUE OBS ALONG WITH THE LATEST DLHWRF
AND HRRR OUTPUT. SO BROUGHT DOWN KHIB TO IFR VISBY AND KHYR TO MVFR.
STILL UNCERTAIN ON FOG FORMATION AT KDLH...AS NAM MOS GUIDANCE HAS
BACKED OFF. EVEN WITH THIS IN MIND STILL CONCERNED WITH LIGHT
WINDS...CLEAR SKIES AND SMALL TEMP/DEWPOINT DEPRESSION THAT FOG
WILL FORM. SO HINTED AT THIS IN THE LATEST TAFS. BY 14Z ALL
TERMINALS WILL BE IN VFR CONDITIONS...WHICH WILL PERSIST THROUGH
THE REST OF THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 73 58 72 56 / 0 10 10 10
INL 77 55 80 59 / 0 10 30 50
BRD 74 58 76 56 / 10 10 10 10
HYR 74 58 70 54 / 0 20 30 20
ASX 76 58 73 55 / 0 10 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM...GSF
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
102 AM CDT THU AUG 27 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 310 PM CDT WED AUG 26 2015
A QUIET WEATHER PERIOD TODAY AND TOMORROW. TEMPERATURES WILL AGAIN
FALL TO WELL BELOW NORMAL VALUES TONIGHT...POSSIBLY REACHING THE
UPPER 30S IN A FEW SPOTS...THEN WARMING UP TO NEAR SEASONABLE
TOMORROW AFTERNOON. NO PRECIP CHANCES IN THE FORECAST...THOUGH SOME
GUIDANCE IS DEPICTING A FAINT CHANCE FOR A SHOWER IN NORTH CENTRAL
MINNESOTA...BASICALLY BEMIDJI TO BRAINERD AND SOUTH...BUT NOT VERY
CONFIDENT IN THESE SOLUTIONS.
TONIGHT...ANOTHER COOL AND CLEAR NIGHT WITH WIND NEARLY CALM. LEANED
TOWARDS MOS GUIDANCE FOR LOWS AS IT TENDS TO PERFORMS WELL IN THESE
SITUATIONS. AREA OF HIGH PRESSURE WILL BE SLIDING OFF TO THE EAST
WHILE A LOW PRESSURE DEEPENS OVER THE CENTRAL PLAINS...CENTERED OVER
CENTRAL NEBRASKA BY TOMORROW MORNING. WHILE LOW LEVEL WINDS TURN OUT
OF THE SOUTH/SOUTHWEST AS THIS SHIFT IN SYNOPTIC FEATURES OCCURS...A
NOCTURNAL INVERSION WILL DEVELOP DUE TO THE CLEAR SKIES AND RAPID
COOLING...THUS SHIELDING US FROM THE SLIGHTLY WARMER AIR WHICH WILL
BEGIN TO BE ADVECTED IN ALOFT. LOWS IN THE UPPER 30S TO MID 40S.
THURSDAY...WARMER WITH INCREASING CLOUDS MAINLY SOUTH OF HIGHWAY 2.
WINDS OUT OF THE SOUTH AT 5 TO 10 MPH. DESPITE THE CLOUDS
TEMPERATURES WILL WARM UP TO THE LOW TO MID 70S...EXCEPT IN THE MID
TO UPPER 60S NEAR THE LAKE AND ESPECIALLY ALONG THE NORTH SHORE OF
LAKE SUPERIOR. THERE IS A VERY LOW CHANCE FOR A SPRINKLE ACROSS EAST-
CENTRAL MINNESOTA LATE IN THE DAY...BASICALLY SOUTH OF HIGHWAY 2 IN
MINNESOTA. LARGE-SCALE LIFT IS NOT STRONG BESIDES SOME WARM AIR
ADVECTION AT LOW/MID LEVELS...BUT DO NOT THINK THERE WILL BE ENOUGH
MOISTURE IN THE COLUMN TO SUPPORT ANY RAIN MAKING IT TO THE
GROUND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 310 PM CDT WED AUG 26 2015
THE NORTHLAND WILL BEGIN THE PERIOD WITH SEASONALLY NORMAL OR
SLIGHTLY WARMER THAN NORMAL WEATHER. A WAVE IS EXPECTED TO EJECT OUT
OF THE ROCKY MOUNTAINS TONIGHT...MOVE THROUGH THE CENTRAL PLAINS
THURSDAY...AND MOVE INTO THE UPPER MIDWEST FRIDAY. THE LATEST
GFS/GEM/ECMWF TRACKS ARE IN FAIRLY GOOD AGREEMENT THAT THE TRACK
WILL BE THROUGH SOUTHERN MINNESOTA OR NORTHERN IOWA...AND THEN INTO
SOUTHERN WISCONSIN. THIS TRACK KEEPS MOST OF THE ASSOCIATED PCPN
SOUTH OF THE FORECAST AREA...BUT THE SOUTHERN FRINGES OF THE
FORECAST AREA COULD BE AFFECTED BY LIGHT RAIN AND SOME THUNDER
THURSDAY NIGHT AND FRIDAY.
THERE WILL ALSO BE AN ELEVATED WARM FRONT ACROSS SOUTHERN MANITOBA
AND NW ONTARIO THURSDAY NIGHT AND FRIDAY...AND NE MINNESOTA WILL BE
UNDER WARM NW FLOW. THE TROUGH ASSOCIATED WITH THE FRONT WILL BEGIN
TO MOVE INTO THE NW FORECAST AREA LATE FRIDAY OR EARLY SATURDAY. THE
GFS/ECMWF/NAM12 ARE INDICATING THE POTENTIAL FOR SHOWERS AND STORMS
ACROSS THE NORTHERN FORECAST AREA LATE FRIDAY AND INTO EARLY
SATURDAY. I PROVIDED LOW PCPN CHANCES FOR FRIDAY AFTERNOON...BUT
THINK THERE MAY BE SOME INITIAL DIFFICULTY OVERCOMING THE CAP FROM
THE WARM FLOW. THE CHANCES WILL BE BETTER FRIDAY NIGHT WHEN THE LOW
LEVEL JET INCREASES AND THE CAP COULD BE OVERCOME.
WEAK HIGH PRESSURE WILL MOVE INTO THE NORTHLAND DURING THE SECOND
HALF OF SATURDAY AND HELP KEEP THE NORTHLAND DRY FOR THE REST OF THE
WEEKEND.
SOUTHERLY FLOW WILL STRENGTHEN LATE OVER THE WEEKEND AND INTO EARLY
NEXT WEEK...BRINGING A WARMING TREND TO THE NORTHLAND. TEMPERATURES
COULD BUILD TO ABOUT 10 DEGREES ABOVE NORMAL BY MONDAY OR TUESDAY. A
TROUGH COULD BRING SHOWERS AND STORMS TO NE MINNESOTA MONDAY INTO
TUESDAY...DEPENDING ON THE TIMING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 102 AM CDT THU AUG 27 2015
HIGH PRESSURE IS CURRENTLY LOCATED OVER THE CENTRAL GREAT LAKES.
THE HIGH WILL MOVE EASTWARDS INTO THE EASTERN GREAT LAKES BY THE
END OF THE FORECAST CYCLE...WHILE A DEVELOPING LOW MOVES FROM THE
CENTRAL PLAINS INTO SOUTHEASTERN SOUTH DAKOTA/EASTERN NEBRASKA.
DUE TO HIGH PRESSURE...SKIES HAVE CLEARED AND WINDS HAVE BECOME
LIGHT. AS A RESULT PATCHY FOG HAS DEVELOPED. EXPECTING WINDS TO
REMAIN OUT OF THE SOUTH/SOUTHEAST AT KINL/KBRD...AND WINDS SHOULD
BE HIGH ENOUGH TO KEEP FOG FROM FORMING. MOST CONFIDENT IN FOG
FORMATION AT KHIB AND KHYR DUE OBS ALONG WITH THE LATEST DLHWRF
AND HRRR OUTPUT. SO BROUGHT DOWN KHIB TO IFR VISBY AND KHYR TO MVFR.
STILL UNCERTAIN ON FOG FORMATION AT KDLH...AS NAM MOS GUIDANCE HAS
BACKED OFF. EVEN WITH THIS IN MIND STILL CONCERNED WITH LIGHT
WINDS...CLEAR SKIES AND SMALL TEMP/DEWPOINT DEPRESSION THAT FOG
WILL FORM. SO HINTED AT THIS IN THE LATEST TAFS. BY 14Z ALL
TERMINALS WILL BE IN VFR CONDITIONS...WHICH WILL PERSIST THROUGH
THE REST OF THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 57 72 57 76 / 10 10 10 10
INL 56 79 59 80 / 0 30 50 20
BRD 60 76 57 80 / 10 0 10 10
HYR 59 73 55 77 / 10 30 20 0
ASX 58 74 57 76 / 10 20 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...GROCHOCINSKI
AVIATION...WL
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
627 PM CDT FRI AUG 28 2015
.DISCUSSION...
Issued at 409 PM CDT FRI AUG 28 2015
Tonight...
Positive tilted shortwave trough as noted in satellite imagery from
IA through KS will slide east tonight. Scattered convection will
form along an associated cold front within a moderately
unstable airmass....at least it will be into the early evening
hours.
A narrow band of convection has finally formed over east
central KS where MLCAPES between 1500-2000J/kg are noted. Further
northeast VFR ceilings within the warm sector have pretty much
capped intense convection as radar shows sputtering area of low
topped showers. The east central KS activity may be the only region
which develops deep convection, albeit the non-severe variety. Will
hit PoPs highest over northern and west central counties until a few
hours after sunset. Thereafter expect a fairly quick drop off in
intensity and coverage as instability hits the skids. Believe the
trend of the HRRR and 12z NAM looks reasonable. QPF will also be
muted. Could see isolated showers form after the passage of the
frontal convection and last into the pre-dawn hours.
Saturday - Sunday...
The above shortwave is expected to flounder over the Mid MO Valley
over the weekend. The h7 shortwave trough will be slow to exit the
CWA resulting in a general region of uvv over the eastern 1/2 of the
CWA. Thinking there will be sufficient breaks in the overcast such
that isolated instability showers/storms will be possible Saturday
afternoon over parts of northeast and central MO. Current
temperature forecast may be a bit too optimistic should the
afternoon clouds fail to break up.
Sunday looks dry with a slight warm-up as the mid level trough
washes out.
Monday - Friday...
The operational models transition to a broadening southwesterly flow
pattern after the upper level ridge axis leans over into the Central
Plains. This will allow warmer more seasonal temperatures and
humidity back into the region. While the h7 temperatures don`t get
overly hot and cap off the environment a lack of any discernible
mid/upper level wave or surface boundaries will greatly limit the
rain chances. As such will go with a dry forecast until some feature
of significance is picked up by the models.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 627 PM CDT FRI AUG 28 2015
Line of convection along approaching cold front beginning to
dissipate this evening. As such...have decided to play a wait and see
approach by maintaining a VCTS mention for now. Its conceivable much
of the precip will pass north of KC area terminals. Otherwise...main
concern heading into the early morning hrs will be the possibility of
developing low stratus. Models seem pretty insistent on this
possibility...but the main question is whether low cigs will extend
far enough south to impact the KC terminals. For now...have offered a
SCT008 mention at MCI...and will reevaluate with the 6z package after
00z model guidance arrives.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...32
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
850 AM CDT THU AUG 27 2015
.MESOSCALE DISCUSSION...
Issued at 0838 AM CDT THU AUG 27 2015
Vigorous elevated convection continues to develop across eastern
Kansas this morning. Isentropic upglide centered around the 310K
level is tapping into an unstable source of air upstream. Most
unstable CAPE (MUCAPE) values earlier were approaching 3000 J/kg
with enough shear for occasional supercell structures. This
resulted in several reports of large hail across extreme southeast
Kansas. Most stones have been around 1 inch in diameter, though we
did received a report of baseball sized hail in Crawford county.
Recent mesoanalysis indicates the MUCAPE values have come down a
bit, between 1500 and 2000 J/kg. This is due to the airmass being
worked over by earlier storms. As was the case earlier mixed
layer CAPE is still rather low, on the order of a few hundred
J/kg and surface based CAPE remains non existent. As a result,
will maintain our main risks as hail to the size of quarters and
cloud to ground lightning.
Expectations over the next few hours is for storms to continue to
move south. Upper level wind fields and cell motion vectors
continue to favor a southward movement (if not south-southwest).
As a result, little in the way of activity is expected to cross
the MO/KS state line. Convection intensity will wane as we head
through the morning hours, with activity expected to exit to the
south/southwest or dissipate by midday.
&&
.SYNOPSIS...
Issued at 0225 AM CDT THU AUG 27 2015
Another pleasant night across the Ozarks region with temperatures
in the mid 50s over the eastern Ozarks to the mid 60s in the west.
Generally seeing a clear sky across the area.
A thunderstorm complex has developed over South Dakota on top of
the ridge axis in an area where upper level energy was moving in
from the west and beginning to break down that ridge. An
instability axis extends almost due south from the current
convective activity through Nebraska and Kansas. HRRR continues to
develop convection towards daybreak over far eastern Kansas on the
edge of this instability in an area of isentropic upglide. Will
need to monitor for this development in a couple/few hours.
&&
.SHORT TERM...(Today and Tonight)
Issued at 0225 AM CDT THU AUG 27 2015
If convection does indeed develop over the far western portion of
the CWA in southeast Kansas and far western Missouri early this
morning, it will have trouble getting much further east. Much
drier and more stable air exists over most of our CWA, so any
potential of convection today will likely be this morning and in
our far western CWA.
Shortwave energy will continue to track eastward today and tonight
with the main energy remaining north of our CWA. Will maintain low
end precipitation chances over northwest 1/3 of the CWA, but
expecting most areas to remain dry tonight as well.
.LONG TERM...(Friday through Wednesday)
Issued at 0225 AM CDT THU AUG 27 2015
Front remains to our west on Friday with the best energy from the
upper level shortwave still off to the north. Again not expecting
much in the way of precipitation coverage, with slight if any
chances existing in northwest portion of the CWA.
The surface front and shortwave energy will begin to push through
the area Friday night and continue into Saturday, but
shower/thunderstorm coverage looks to remain scattered in nature
with this system, and it looks like not everyone will get
precipitation.
Upper level ridging begins to build back into the area by Saturday
night and precipitation chances through the remainder of the
extended period look to be minimal at this time. Will also see
temperatures rise back to more normal readings for this time of
year.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1155 PM CDT WED AUG 26 2015
VFR conditions are expected through Thursday evening. A few
thunderstorms will be possible around sunrise on Thursday across
extreme southeastern Kansas, but they are expected to remain west
of the Joplin aerodrome at this time. Variable winds tonight will
become southeast on Thursday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Gagan
SYNOPSIS...Lindenberg
SHORT TERM...Lindenberg
LONG TERM...Lindenberg
AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
225 AM CDT THU AUG 27 2015
.SYNOPSIS...
Issued at 0225 AM CDT THU AUG 27 2015
Another pleasant night across the Ozarks region with temperatures
in the mid 50s over the eastern Ozarks to the mid 60s in the west.
Generally seeing a clear sky across the area.
A thunderstorm complex has developed over South Dakota on top of
the ridge axis in an area where upper level energy was moving in
from the west and beginning to break down that ridge. An
instability axis extends almost due south from the current
convective activity through Nebraska and Kansas. HRRR continues to
develop convection towards daybreak over far eastern Kansas on the
edge of this instability in an area of isentropic upglide. Will
need to monitor for this development in a couple/few hours.
&&
.SHORT TERM...(Today and Tonight)
Issued at 0225 AM CDT THU AUG 27 2015
If convection does indeed develop over the far western portion of
the CWA in southeast Kansas and far western Missouri early this
morning, it will have trouble getting much further east. Much
drier and more stable air exists over most of our CWA, so any
potential of convection today will likely be this morning and in
our far western CWA.
Shortwave energy will continue to track eastward today and tonight
with the main energy remaining north of our CWA. Will maintain low
end precipitation chances over northwest 1/3 of the CWA, but
expecting most areas to remain dry tonight as well.
.LONG TERM...(Friday through Wednesday)
Issued at 0225 AM CDT THU AUG 27 2015
Front remains to our west on Friday with the best energy from the
upper level shortwave still off to the north. Again not expecting
much in the way of precipitation coverage, with slight if any
chances existing in northwest portion of the CWA.
The surface front and shortwave energy will begin to push through
the area Friday night and continue into Saturday, but
shower/thunderstorm coverage looks to remain scattered in nature
with this system, and it looks like not everyone will get
precipitation.
Upper level ridging begins to build back into the area by Saturday
night and precipitation chances through the remainder of the
extended period look to be minimal at this time. Will also see
temperatures rise back to more normal readings for this time of
year.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1155 PM CDT WED AUG 26 2015
VFR conditions are expected through Thursday evening. A few
thunderstorms will be possible around sunrise on Thursday across
extreme southeastern Kansas, but they are expected to remain west
of the Joplin aerodrome at this time. Variable winds tonight will
become southeast on Thursday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SYNOPSIS...Lindenberg
SHORT TERM...Lindenberg
LONG TERM...Lindenberg
AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
536 PM MDT FRI AUG 28 2015
AVIATION SECTION UPDATED.
.UPDATE...
AN EARLY UPDATE WAS NEEDED TO INCREASE WINDS ALONG NORTHERN PORTIONS
OF THE ROCKY MOUNTAIN FRONT AND ADJACENT PLAINS. OBSERVATIONS IN
THIS AREA INDICATE WIND GUSTS NEAR 45 MPH. ANALYSIS AND SHORT-TERM
GUIDANCE SHOW THESE WINDS ARE THE RESULT OF A MINOR SHORTWAVE
PASSING QUICKLY THROUGH THE SOUTHWESTERLY FLOW. EXPECT THESE WINDS
TO DECREASE BY MIDNIGHT AS SUGGESTED BY HRRR GUIDANCE. RADAR AND
SATELLITE INDICATES A BAND OF SHOWERS ASSOCIATED WITH THIS WAVE.
ALSO RAISED POPS BARELY INTO SLIGHT CHANCE CATEGORY AS LOW LEVELS
REMAIN EXCEEDINGLY DRY. GUSTY WINDS WILL BE ASSOCIATED WITH VIRGA AS
SHOWERS PASS OVERHEAD. PN
.DISCUSSION...
TONIGHT THROUGH SUNDAY...SOUTHWESTERLY FLOW STRENGTHENS OVER THE
REGION TONIGHT AS A PERSISTENT RIDGE FINALLY MOVES AWAY TO THE
EAST AND A VIGOROUS TROUGH IMPACTS THE PACIFIC NORTHWEST. THE
AIRMASS REMAINS WARM AND DRY ON SATURDAY WHILE SOUTHWEST WINDS
INCREASE UNDER STRENGTHENING PRESSURE GRADIENTS. A RED FLAG
WARNING HAS BEEN ISSUED IN ANTICIPATION OF CRITICAL FIRE WEATHER
CONDITIONS SATURDAY AFTERNOON. ISOLATED TO SCATTERED SHOWERS WILL
BE POSSIBLE AS A WEAK COLD FRONT ACROSS THE AREA...BUT WITH
LIMITED MOISTURE AT LOW LEVELS...SOME STORMS WILL BE CAPABLE OF
PRODUCING ERRATIC GUSTY WINDS. WINDS TURN WESTERLY AND REMAIN
ELEVATED BEHIND THE FRONT SATURDAY NIGHT AND SUNDAY. HIGH
TEMPERATURES SUNDAY WILL DROP INTO THE UPPER 70S TO NEAR 80. AIR
QUALITY REMAINS A PROBLEM DUE TO WILDFIRE SMOKE. THE FRONTAL
PASSAGE MAY PROVIDE SOME RELIEF SUNDAY...BUT SMOKE IS LIKELY TO
RETURN GIVEN THE EXTENT AND CONTINUING ACTIVITY OF WESTERN
WILDFIRES. PN
SUNDAY NIGHT THROUGH FRIDAY...MAIN PLAYERS IN THE MEDIUM RANGE
FORECAST CONTINUE TO BE AN UPPER LEVEL TROUGH OVER THE WEST COAST
OF CANADA AND RIDGING OVER THE HIGH PLAINS/GREAT LAKES REGION.
MONTANA REMAINS BENEATH A SOMEWHAT UNSTABLE SOUTHWEST FLOW ALOFT
THROUGH MUCH OF THE FORECAST PERIOD. MODELS REMAIN IN FAIRLY GOOD
AGREEMENT AS THEY EXTEND THE UPPER TROUGH SOUTHWARD INTO THE
PACIFIC NORTHWEST AND THEN ATTEMPT TO PROGRESS IT EASTWARD INTO
THE NORTHERN ROCKIES. FORECAST CONTINUES TO BE GENERALLY DRY
ACROSS MUCH OF MY FORECAST AREA BUT HAVE INCREASED POPS OVER THE
GLACIER PARK REGION INTO THE CHANCE CATEGORY FOR TUESDAY ONWARD.
TEMPERATURES ALSO REMAIN NEAR OR SLIGHTLY ABOVE SEASONAL AVERAGES
FOR MUCH OF THE PERIOD BUT HAVE TRENDED SOMEWHAT COOLER FOR
THURSDAY. STILL NO SIGN OF A SEASON- ENDING EVENT FOR WILDFIRES SO
AM KEEPING MENTION OF SMOKE IN THROUGH THE ENTIRE TIME FRAME. MPJ
&&
.AVIATION... UPDATED 2346Z. VFR TO MVFR CONDITIONS PREVAIL WITH
VISIBILITY REDUCTIONS AT TIMES DUE TO SMOKE. LOW TO MID LEVEL CLOUDS
ARE SPREADING THROUGH THE AREA WITH INCREASING SOUTHWEST WINDS
ALOFT. SCATTERED SHOWERS ARE POSSIBLE THIS EVENING...PRODUCING
LITTLE RAINFALL AND GUSTY ERRATIC WINDS. STRONGER SOUTHWEST WINDS
MIX TO THE SURFACE ON SATURDAY AFTERNOON. PN
&&
.FIRE WEATHER... STRONG WINDS ALONG THE ROCKY MOUNTAIN FRONT THIS
EVENING WILL TAPER THROUGH MIDNIGHT AS A MINOR SHORTWAVE EXITS ONTO
THE PLAINS. A RED FLAG WARNING IS NOW IN EFFECT FOR NOON TO 9 PM MDT
SATURDAY FOR FIRE ZONES 112/114/116/117/118. FORECAST IS STILL ON
TRACK FOR LOW HUMIDITY CONDITIONS AND GUSTY WINDS TO DEVELOP AHEAD
OF A PACIFIC COLD FRONT THAT WILL CROSS EAST OF THE CONTINENTAL
DIVIDE BY EARLY SATURDAY EVENING. LOOK FOR AFTERNOON HUMIDITY VALUES
TO DROP INTO THE 15 TO 25 PERCENT RANGE WITH WIND GUSTS OF 20 TO 30
MPH AHEAD OF THE FRONT. WINDS WILL REMAIN GUSTY (WITH GUSTS OF 30-35
MPH) INTO SATURDAY EVENING FOLLOWING FRONTAL PASSAGE BEFORE
GRADUALLY TAPERING OFF AFTER SUNSET.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 61 92 59 77 / 10 20 20 10
CTB 56 88 53 71 / 10 10 10 10
HLN 56 91 55 78 / 10 20 20 20
BZN 54 91 54 80 / 10 10 20 20
WEY 44 81 45 71 / 0 20 20 20
DLN 55 88 52 77 / 10 20 20 20
HVR 58 95 59 80 / 10 10 30 20
LWT 58 94 58 78 / 0 10 20 30
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TO 9 PM MDT SATURDAY FOR MTZ112-114-
116>118.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
258 PM MDT THU AUG 27 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...
THE EMBEDDED SHORT-WAVE TROUGH WHICH RODE UP AND AROUND THE RIDGE
OF HIGH PRESSURE HAS NOW PASSED EAST OF MONTANA. ANY REMAINING
CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY THIS AFTERNOON AND
EVENING WILL BE MANIFESTED BY A RESIDUAL VERY SMALL-SCALE KINK IN
THE FLOW ALOFT APPROACHING FROM CENTRAL MONTANA AS THE UPPER-
LEVEL RIDGE NOW BEGINS TO RE-ASSERT ITSELF ACROSS THE REGION. EVEN
WITH THE TIME FRAME VERY NEAR...MODELS ARE STILL IN SIGNIFICANT
DISAGREEMENT AS TO HOW MUCH PRECIPITATION WILL FALL ACROSS NE
MONTANA THROUGH THIS EVENING. GFS AND HRRR ARE NEARLY COMPLETELY
DRY...THE NAM SHOWS A FEW SCATTERED AREAS OF LIGHT PRECIP...AND
THE EC CONTINUES TO HOLD ON TO A WIDE AREA OF WETTING RAIN ACROSS
THE WESTERN HALF OF OUR CWA. BY LATE TONIGHT...IT WILL BECOME
EVIDENT WHICH MODEL SOLUTION IS MORE TRUSTWORTHY IN THE NEAR SHORT
TERM.
REGARDLESS...EARLY FRIDAY MORNING THROUGH SATURDAY NIGHT SHOWS
MUCH BETTER MODEL CONSENSUS IN KEEPING NE MONTANA DRY AS A BONE
UNDER A DECENT RIDGE OF HIGH PRESSURE. INDEED...HIGH TEMPERATURES
FOR SATURDAY WILL EASILY REACH 100 DEGREES FOR MANY LOCATIONS. AT
THIS TIME...FIRE WEATHER CONCERNS WILL GENERALLY STILL BE HELD IN
CHECK AS SATURDAYS WIND SPEEDS MAY BE AROUND A BORDERLINE 15 MPH
WITH RH VALUES ALSO IN THE LOWER TEENS. WILL NEED TO KEEP A CLOSE
EYE ON THE POSSIBILITY FOR SLIGHTLY STRONGER WINDS AND/OR SLIGHTLY
DRIER RH VALUES...WHICH WOULD RAISE FIRE WEATHER CONCERNS.
LATER ON SATURDAY...THE FLOW ALOFT BEGINS TO TURN MORE FROM THE
SW...COURTESY OF THE LARGE PACNW TROUGH WHICH WILL PERSIST THROUGH
THE REMAINDER OF THE ENTIRE FORECAST WITH OFF AND ON CHANCES FOR
SHOWERS AND THUNDERSTORMS THROUGHOUT. BMICKELSON
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
GOING FORECAST LOOKED GOOD. MODEL CONFIDENCE ON PRECIPITATION IS
LOW AS STRONG UNSTABLE SW JET STREAM INTERACTS WITH A DRY DESERT AIR
MASS. TFJ
PREVIOUS DISCUSSION...
HOT UPPER RIDGE OVER THE REGION EXPECTED TO BREAK DOWN OVER THE
WEEKEND AS THE UPPER LOW CURRENTLY IN THE EAST PACIFIC MOVES
ONSHORE. THIS TROF WILL BE REINFORCED BY WAVES DROPPING OUT OF
ALASKA...MAINTAINING THE TROF OVER WESTERN CANADA THROUGH NEXT
WEEK.
COLD FRONT SWEEPS ACROSS THE REGION SATURDAY NIGHT WITH THE BEST
CHANCE FOR SHOWERS OR THUNDERSTORMS FOLLOWING THE FRONT. AS THE
UPPER TROF MOVES ONSHORE...SOUTHWEST FLOW INTO EASTERN MONTANA
WILL KEEP TEMPERATURES NEAR NORMAL FOR THE REMAINDER OF THE WEEK.
SOME MOISTURE MAY WORK INTO THE REGION BUT NONE OF THE MEDIUM
RANGE MODELS INDICATE SIGNIFICANT UPPER ENERGY TO TRIGGER
PRECIPITATION. EBERT
&&
.AVIATION...
VFR.
AN ISOLATED SHOWER OR TWO MAY MOVE INTO THE KGGW VICINITY THIS
LATE TODAY...OTHERWISE EXPECT CLOUDS AOA 10K AGL AND LIGHT AND
VARIABLE WINDS THROUGH TONIGHT.
SMOKE MAY RETURN TO THE AREA LATE FRIDAY WITH THE WEST WINDS
RETURNING. TFJ
&&
.FIRE WEATHER...
NEXT FOCUS FOR FIRE WEATHER CONCERNS WILL BE SATURDAY AS THE
UPPER-LEVEL RIDGE OF HIGH PRESSURE WILL RE-ASSERT ITSELF OVER THE
REGION. A BREEZY TO SLIGHTLY GUSTY SOUTH WIND WILL SET UP.
SATURDAYS HIGH TEMPERATURES WILL CLIMB TO AROUND 100 DEGREES AND
THE LOWEST RH VALUES WILL BE SOMEWHERE IN THE LOW TO MID TEENS.
ONLY SLIGHT CHANGES IN THESE PARAMETERS WOULD RAISE FIRE WEATHER CONCERNS
FOR SATURDAY. WILL DEFER TO NEXT THE SHIFT AS SATURDAY IS STILL
DAY 3 OF THE FORECAST. BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1126 PM CDT WED AUG 26 2015
.SYNOPSIS...
ISSUED AT 341 PM CDT WED AUG 26 2015
UPPER LEVEL RIDGE ACROSS THE ROCKIES...WITH A TROUGH ACROSS NEW
ENGLAND. SHORTWAVE MOVING ACROSS THE CREST OF THE RIDGE...CAUSING
THE RIDGE TO FLATTEN. ELONGATED SFC HIGH ACROSS MUCH OF THE MISS RVR
VALLEY. A STALLED BOUNDARY ANALYZED FROM A LOW OVER MONTANA...THEN
MEANDERS SE INTO CENTRAL KS. ALSO A DISTINCT DRY LINE ACROSS THE
PANHANDLE AND EASTERN COLORADO...WHERE DEW POINTS HAVE FALLEN INTO
THE 30S AND 40S WITH TEMPS NEAR/ABOVE 100.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 341 PM CDT WED AUG 26 2015
MAIN FOCUS WILL BE THUNDERSTORM CHANCES THE NEXT 24 HOURS. FIRST
WILL BE EARLY THIS EVENING ACROSS SOUTHWEST NEB...ALONG THE DRY
LINE. A COUPLE CU CLOUDS HAVE DEVELOPED...HOWEVER DEVELOPMENT IS
MINIMAL AND SHALLOW...SUGGESTING A CAP STILL IN PLACE. THE
NAM/GFS/EC KEEP THIS AREA QUIET...HOWEVER THE NEAR TERM RAP/HRRR IN
AGREEMENT A FEW ISOLD STORMS TO DEVELOP. THE RAP AND HRRR SUGGEST
STORMS SHOULD ALREADY BE DEVELOPED. HAVE A DRY FORECAST AT THE
MOMENT...THINKING THE NEAR TERM MODELS ARE SLIGHTLY OVERDONE WITH
MOISTURE AVAILABLE. THAT SAID...INVERTED V SOUNDING WEST OF THE DRY
LINE AND CAN NOT RULE OUT A STRAY STRONG STORM DEVELOPING. WILL
CONTINUE TO MONITOR.
NEXT FOCUS WILL BE FOLLOWING A COMBINATION OF A LEAD SHORTWAVE
RIDING THE CREST OF THE RIDGE ACROSS SOUTHERN S DAKOTA AND INTO
NORTHEASTERN NEB. THIS WILL COMBINE WITH LIFT FROM A NOCTURNAL LL
JET. MODELS IN GOOD AGREEMENT WITH THE NOSE NEAR THE NEB/S DAKOTA
BORDER. ANY ACTIVITY SHOULD DRIFT EAST THEN TURN TO THE SOUTHEAST.
THIS FOCUSES ACTIVITY ACROSS THE NORTHERN ZONES.
TOMORROW THE MAIN WAVE WILL CROSS THE AREA. MODELS HAVE SLOWED THE
SPEED FROM EARLIER RUNS. THIS WAVE HAS GOOD SUPPORT AND THE
DEEPENING MID LEVEL LOW WILL AID IN LIFT. MORNING CHANCES ARE
MINIMAL AS CAP IN PLACE...ALTHOUGH WILL HAVE TO MONITOR POSSIBLE
REMNANT OUTFLOW BOUNDARIES. OTHERWISE EXPECT EARLY AFTERNOON
DEVELOPMENT ACROSS THE WESTERN CWA WHICH WILL MOVE EAST. GOOD
INSTABILITY AND MARGINAL SHEAR SHOULD BE ENOUGH FROM SOME STRONG
STORMS. SHOULD SEE SOME MORE CLOUDS AND HIGHS HOLD IN THE 80S FOR
MOST LOCATIONS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 341 PM CDT WED AUG 26 2015
THE FRONT SWINGS THROUGH CENTRAL NEBRASKA THURSDAY NIGHT...BUT
MOISTURE WRAPPING AROUND THE UPPER LOW/TROUGH COULD STILL BRING THE
POSSIBILITY OF SHOWERS AND ISOLATED THUNDERSTORMS TO NORTH CENTRAL
NEBRASKA FRIDAY MORNING.
AFTER FRIDAY...LOW LEVEL FLOW WILL RETURN TO THE SOUTH AND BRING
WARMER TEMPERATURES TO CENTRAL AND WESTERN NEBRASKA THROUGH
SATURDAY. THE RETURN FLOW WILL ALSO BEGIN BRINGING MOISTURE TO THE
HIGH PLAINS FROM THE SOUTHWEST U.S. AND INCREASING THE LOW LEVEL
THETA-E. IN ADDITION...DESTABILIZATION IS LIKELY IN THE THETA-E
RIDGE. ANOTHER BOUNDARY COMING ACROSS THE STATE COULD BRING AT LEAST
A SLIGHT CHANCE OF THUNDERSTORMS TO WESTERN NEBRASKA NEBRASKA EARLY
NEXT WEEK. CURRENT INDICATIONS ARE THAT THE BEST MOISTURE WILL BE
OVER THE SOUTHEAST U.S. AS A TROPICAL SYSTEM INTERACTS WITH A WEAK
STATIONARY FRONT ACROSS THE GULF COAST STATES AND THE MOISTURE ON
THE HIGH PLAINS WILL BE LIMITED TO PRECIPITABLE WATER OF AN INCH OR
LESS. THIS WOULD ALSO LIMIT THE COVERAGE OF THE CONVECTION AND
PRETTY MUCH LIMIT IT TO THE NEBRASKA PANHANDLE AND WESTERN
SANDHILLS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1125 PM CDT WED AUG 26 2015
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH THURSDAY AFTERNOON. OVERNIGHT...THERE IS A
CHANCE OF THUNDERSTORMS ACROSS NORTHERN NEBRASKA...INCLUDING KVTN.
CURRENT COVERAGE IN NRN NEBRASKA IS TOO ISOLATED TO WARRANT TSRA
IN THE CURRENT FORECAST. HOWEVER...AS AN UPPER LEVEL SYSTEM MOVES
ACROSS WESTERN NEBRASKA ON THURSDAY...ISOLATED TO SCATTERED
THUNDERSTORMS WILL OCCUR IN THE AFTERNOON/EVENING. HAVE KEPT A
TEMPO FOR 5SM -TSRA BKN080CB FOR BOTH THE KLBF AND KVTN TERMINALS
FROM 21Z- 02Z/27TH. AFTER 02Z...THUNDERSTORMS SHOULD REMAIN EAST
OF THE TERMINALS WITH THE CHANCE FOR MVFR CONDITIONS TO DEVELOP
INTO THE KVTN TERMINAL AFTER 03Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...SPRINGER
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
853 PM CDT FRI AUG 28 2015
.UPDATE...
ISSUED AT 845 PM CDT FRI AUG 28 2015
ADDED A MENTION OF FOG FOR TONIGHT INTO SATURDAY MORNING FOR
LOCATIONS GENERALLY ALONG AND EAST OF US HIGHWAY 83...WHERE MID
TO UPPER 60S F DEWPOINTS WERE OBSERVED AS OF 01 UTC. THE 23-00 UTC
RAP ITERATIONS HOLD THIS MOISTURE IN THROUGH THE NIGHT...SUPPORTED
BY THE HRRR VISIBILITY PRODUCT RAPIDLY DECREASING LATE TONIGHT
INTO SATURDAY MORNING FOR THE AFOREMENTIONED AREAS.
UPDATE ISSUED AT 633 PM CDT FRI AUG 28 2015
DID ADD AREAS OF SMOKE TO THE FORECAST FOR THE REMAINDER OF THE
EVENING INTO SATURDAY GIVEN SATELLITE AND SURFACE OBSERVATION
TRENDS THROUGH 23 UTC. OTHERWISE...THE FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 345 PM CDT FRI AUG 28 2015
MAIN CONCERN IN THE SHORT TERM WILL BE FIRE WEATHER POTENTIAL OVER
WESTERN NORTH DAKOTA FOR SATURDAY. AFTER A QUIET NIGHT TONIGHT A
VERY WARM AIRMASS WILL ALLOW TEMPERATURES TO RISE INTO THE 90S TO
NEAR 100 ACROSS WESTERN NORTH DAKOTA SATURDAY. MINIMUM RELATIVE
HUMIDITY COULD FALL AS LOW AS 15 PERCENT. A FIRE WEATHER WATCH HAS
BEEN ISSUED FOR WESTERN NORTH DAKOTA...WEST OF THE MISSOURI RIVER
UP TO LAKE SAKAKAWEA AND GENERALLY WEST OF HIGHWAY 83 NORTH OF
LAKE SAKAKAWEA.
OTHERWISE...A WEAK TROUGH OF LOW PRESSURE WAS THE FOCUS FOR A FEW
THUNDERSTORMS FRIDAY MORNING AND EARLY AFTERNOON ACROSS NORTHEAST
ND. AS THIS TROUGH SLIDES SOUTHEAST THIS AFTERNOON AND EVENING AN
ISOLATED THUNDERSTORM MAY YET BE POSSIBLE ACROSS THE JAMES RIVER
VALLEY INTO THIS EVENING. OTHERWISE WILL KEEP A MENTION OF SMOKE
IN TONIGHT MOST OF WEST AND CENTRAL NORTH DAKOTA. THE SMOKE HAS
BEEN MAINLY ALOFT BUT SKIES ARE QUITE COVERED WITH IT AND THERE
CONTINUES TO BE A SCENT OF IT AT THE SURFACE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 PM CDT FRI AUG 28 2015
WARM TEMPERATURES AND PERIODIC THUNDERSTORM CHANCES WILL HIGHLIGHT
THE EXTENDED FORECAST PERIOD NEXT WEEK.
WESTERN CONUS UPPER LEVEL RIDGE WILL AMPLIFY INTO THE CENTRAL U.S
OVER THE UPCOMING WEEKEND...THEN TRANSLATE TO THE EASTERN CONUS NEXT
WEEK PUTTING SOUTHWEST FLOW ALOFT INTO THE NORTHERN PLAINS THROUGH
THE WORK WEEK. THE UPPER RIDGE THIS WEEKEND WILL BRING WELL ABOVE
NORMAL TEMPERATURES AND LIMITED PRECIPITATION CHANCES TO WESTERN
AND CENTRAL NORTH DAKOTA THROUGH SUNDAY DAYTIME.
ON SUNDAY WE ARE EXPECTING SLIGHTLY COOLER TEMPERATURES IN THE
NORTHWEST. THE THERMAL RIDGE SHIFTS INTO CENTRAL NORTH
DAKOTA...THUS MINOT AND BISMARCK COULD SEE TEMPERATURES
APPROACHING RECORDS ONCE AGAIN FOR SUNDAY...BUT MUCH WILL DEPEND
ON THE TIMING OF AN APPROACHING COLD FRONT.
ISOLATED THUNDERSTORMS WILL ENTER THE FORECAST SUNDAY NIGHT WITH
ENERGY ALOFT AND THE AFOREMENTIONED COLD FRONT/SFC BOUNDARY
MOVING SLOWLY SOUTH AND EAST THROUGH NORTH DAKOTA...COOLING
TEMPERATURES BACK DOWN INTO THE 80S FOR MONDAY.
BROAD SOUTHWEST UPPER LEVEL FLOW WILL THEN PERSIST THROUGH NEXT
WEEK. NO MAJOR SYSTEMS DEPICTED...BUT WE CAN EXPECT DAILY ISOLATED
TO SCATTERED THUNDERSTORM CHANCES WITH ANY EMBEDDED SHORTWAVE
WHICH TRAVELS THROUGH THE FLOW ALOFT COUPLED WITH ANY ASSOCIATED
BOUNDARY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 845 PM CDT FRI AUG 28 2015
MVFR VISIBILITY IN SMOKE FROM NORTHWEST U.S. FIRES ARE POSSIBLE
AT KDIK/KISN/KBIS/KMOT THIS EVENING INTO SATURDAY MORNING. SMOKE
MAY BE DENSE ENOUGH TO DROP VISIBILITY TO IFR AT KDIK AND KISN
TONIGHT. PATCHY FOG IS POSSIBLE IN THE KJMS/KBIS VICINITY LATE
TONIGHT INTO SATURDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
EVENING FOR NDZ001-002-009>011-017>021-031>034-040>045.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1243 PM CDT THU AUG 27 2015
.UPDATE...
ISSUED AT 1241 PM CDT THU AUG 27 2015
CONSIDERABLE HIGH CLOUD COVER OVER THE SRN 2/3 OF THE FCST AREA.
THAT COMBINED WITH SOME HIGH LEVEL SMOKE ENOUGH TO TAME TEMPS DOWN
A TAD...MOST NOTICEABLE IT SEEMS IN THE RED RIVER VALLEY INTO NW
MN AS WINDS ARE THE LIGHTEST. SO LOWERED HIGHS TODAY DOWN A FEW
RRV AND EAST. O/W ANY PRECIP REMAINING WELL SOUTH OF THE BORDER
AND WILL DO SO.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
FORECAST CHALLENGES CONCERN LOW END PCPN CHANCES ACROSS THE FAR
SOUTH AND NORTH AS WELL AS TEMPERATURES. MODELS IN REASONABLE
AGREEMENT THROUGH THE PERIOD.
CONVECTIVE COMPLEX OVER SD ASSOCIATED WITH WARM ADVECTION ZONE
AND ON NOSE OF LOW LEVEL JET AHEAD OF E WYO SHORT WAVE. SOME
WEAKER ECHOES FARTHER NORTH CLIPPING THE THE FAR SW FA HOWEVER
HAVE DOUBTS THAT ANY OF THIS REACHING THE GROUND. HRRR HANDLING
CURRENT CONVECTION WELL AND AS STRONGER CONVECTION OUTRUNS
INSTABILITY AXIS AND LOW LEVEL JET WEAKENS STORMS SHOULD WEAKEN AS
THEY CLIP THE ND/SD BORDER AREA LATER THIS MORNING. BASED ON THIS
SCENARIO WILL MAINTAIN SOME LOW POPS ACROSS THE FAR SOUTH. COULD
SEE SOME MORE DEVELOPMENT THIS AFTERNOON AS SURFACE LOW TRACKS
ACROSS NE HOWEVER MOST CAM/SHORT TERM MODEL GUIDANCE KEEPS THIS
JUST SOUTH OF THE BORDER. COOLEST READINGS LIKELY ACROSS THE FAR
SOUTH WITH MORE CLOUD COVER. OTHERWISE WITH FAIRLY WARM COLUMN AND
WARMER START TEMPERATURES SHOULD RECOVER TO AT OR A BIT ABOVE
AVERAGE.
SURFACE LOW WILL CONTINUE TO TRACK EAST ALONG THE NE/SD BORDER
AREA TO NEAR SUX BY FRIDAY MORNING. MODEL GUIDANCE CONTINUES TO
INDICATE NORTHERN FRINGE OF PCPN SHIELD POSSIBLY CLIPPING FAR
SOUTHERN FA SO WILL CONTINUE LOW POPS THERE. WITH LOW LEVEL
MOISTURE RECOVERY MINIMUM TEMPERATURES WILL BE WARMER.
LOW PULLS AWAY FRIDAY WITH COLUMN CONTINUING TO WARM. THIS SHOULD
ALLOW TEMPERATURES TO RECOVER TO ABOVE AVERAGE VALUES MOST AREAS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
WEAK SHORTWAVE ACROSS S MB FRIDAY NIGHT MAY BRING SOME PCPN
POTENTIAL TO NORTHERN AREAS. LACK OF INSTABILITY AND LOW LEVEL JET
SHOULD LIMIT COVERAGE AND ANY RESIDUAL CONVECTION SHOULD WEAKEN
EARLY SATURDAY.
COLUMN CONTINUES TO WARM SATURDAY SO WELL ABOVE AVERAGE
TEMPERATURES EXPECTED WITH WESTERN AREAS APPROACHING 90.
THE EXTENDED PERIOD STARTS WITH UPPER LEVEL RIDGING OVER THE NRN
PLAINS ALLOWING WARMER TEMPS...MAINLY IN THE 80S...TO REMAIN OVER
THE AREA. THE PATTERN BEGINS TO CHANGE BY MONDAY AS AN UPPER TROF
BEGINS TO DEEPEN AND SHIFT OVER THE INTERMOUNTAIN WEST...BRINGING SW
FLOW ALOFT TO THE AREA. A SERIES OF UPPER DISTURBANCES ARE EXPECTED
TO PROPAGATE THROUGH THE FLOW...BRINGING INCREASED CHANCES FOR
SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA LATE IN THE PERIOD.
TEMPERATURES LATE IN THE PERIOD ARE EXPECTED TO COOL A BIT...TO MORE
SEASONAL VALUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1241 PM CDT THU AUG 27 2015
VFR WITH LIGHT WINDS...SOME PATCHY BKN MID CLOUD AT BJI
EARLY THIS AFTN OTHERWISE HIGH CIRRUS TODAY AND TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...VOELKER
LONG TERM...HOPKINS/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1237 PM CDT THU AUG 27 2015
.UPDATE...
ISSUED AT 1237 PM CDT THU AUG 27 2015
TEMPERATURES HAVE BEEN SLOWER TO RISE THAN EXPECTED...BUT NO BIG
CHANGES ON OVERALL MAX TEMPERATURES EXPECTED FOR THE DAY. CURRENT
FORECAST ON TRACK.
UPDATE ISSUED AT 949 AM CDT THU AUG 27 2015
ITERATIONS OF THE HRRR MODEL EACH HOUR INDICATE WANING CHANCES FOR
ANY SHOWERS ACROSS THE SOUTHERN TIER OF COUNTIES. UPPER LEVEL
DISTURBANCE ACROSS SOUTH DAKOTA WAS ASSOCIATED WITH ONGOING
SCATTERED SHOWERS IN SOUTH DAKOTA. HAVE TRIMMED CHANCES IN NORTH
DAKOTA TO SLIGHT CHANCE. FOR THE AFTERNOON HOWEVER...KEPT CHANCE
MENTIONS IN THE SOUTH WITH MODELS INDICATING AFTERNOON CAPE AND
PLENTY OF LOW LEVEL MOISTURE AVAILABLE...WITH DEWPOINTS IN THE UPPER
50S AND LOWER 60S ACROSS THE REGION. PATCHY FOG WAS DISSIPATING
ACROSS THE REGION...THUS THE EARLIER UPDATE TO ADD PATCHY FOG
UNTIL AROUND 10 AM CDT LOOKS ON TRACK.
OTHERWISE ONLY HOURLY TRENDS IN TEMPERATURES AND WINDS WERE UPDATED
WITH NO CHANGES IN THE OVERALL EXPECTED TEMPS THIS AFTERNOON.
UPDATE ISSUED AT 627 AM CDT THU AUG 27 2015
CONVECTION TRACKING SOUTHEAST ACROSS EASTERN SOUTH DAKOTA.
UPSTREAM NEXT SHORTWAVE IS TRACKING ACROSS WESTERN WYOMING. STILL
A LITTLE CONVECTIVE DEBRIS LINGERING ACROSS NORTHERN SOUTH DAKOTA
BUT SHOULD BE RELATIVELY QUIET ACROSS SOUTHERN NORTH DAKOTA FOR
THE NEXT FEW HOURS. DID KEEP SOME SLIGHT CHANCE POPS OVER THE FAR
SOUTH EARLY THIS MORNING...THEN BEGAN INCREASING POPS ACROSS THE
SOUTH MID TO LATE MORNING. STILL JUST LOOKING AT CHC POPS FAR
SOUTH TODAY TO SLIGHT CHANCE UP TO THE I94 CORRIDOR. OTHERWISE NO
SIGNIFICANT CHANGES TO THE GOING FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 238 AM CDT THU AUG 27 2015
WARMING TEMPERATURES AND ISOLATED THUNDERSTORM POTENTIAL IN THE
SOUTH HIGHLIGHT THE SHORT TERM.
AN UPPER LEVEL LOW WAS LOCATED OVER NORTHERN WYOMING...TRIGGERING
WIDESPREAD SHOWERS AND THUNDERSTORMS OVER CENTRAL SOUTH DAKOTA
EARLY THIS MORNING. AS AN ASSOCIATED SURFACE LOW DEEPENS ON THE
SOUTH DAKOTA NEBRASKA BORDER...PRECIPITATION SHOULD
EXPAND...NUDGING INTO THE COUNTY WARNING AREA LATER THIS MORNING
AND INTO THIS AFTERNOON. THE BEST CHANCES FOR A FEW SHOWERS AND
THUNDERSTORMS WILL BE IN OUR MOST SOUTHERN ZONES...SOUTH OF
INTERSTATE 94. WITH MEAGER INSTABILITY AND WEAK DEEP LAYER SHEAR
FORECAST...SEVERE WEATHER DOES NOT APPEAR TO BE A THREAT. THURSDAY
WILL ALSO FEATURE WARMER TEMPERATURES AS THE UPPER 80S CREEP INTO
THE WEST.
ANOTHER SHORTWAVE WILL APPROACH OUR NORTHWEST COUNTIES THURSDAY
NIGHT...BRINGING A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM TO
THE NORTHWEST AND NORTH CENTRAL PARTS OF THE STATE. HOWEVER...AT
THIS TIME IT APPEARS THAT THE STRONGEST FORCING MECHANISMS WILL
REMAIN NORTH OF THE INTERNATIONAL BORDER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 238 AM CDT THU AUG 27 2015
WARM TEMPERATURES AND PERIODIC THUNDERSTORM CHANCES HIGHLIGHT THE
EXTENDED FORECAST PERIOD.
DETERMINISTIC AND ENSEMBLE MODELS ARE IN GOOD AGREEMENT OVER THE
NORTHERN PLAINS THROUGH THE LONG TERM PERIOD AS A MEAN WESTERN CONUS
UPPER LEVEL RIDGE AMPLIFIES OVER THE CENTRAL U.S OVER THE UPCOMING
WEEKEND...THEN TRANSLATES TO THE EASTERN CONUS NEXT WEEK. THIS WILL
BRING ABOVE NORMAL TEMPERATURES AND LIMITED PRECIPITATION CHANCES TO
WESTERN AND CENTRAL NORTH DAKOTA FRIDAY THROUGH SUNDAY. AN ISOLATED
THUNDERSTORM CAN NOT BE COMPLETELY RULED OUT FRIDAY ALONG THE
CANADIAN BORDER ON THE PERIPHERY OF THE BUILDING RIDGE. BUT WILL
KEEP A DRY FORECAST FOR NOW. FORECAST HIGH ARE EXPECTED TO RANGE
FROM THE MID 80S EAST TO LOWER 90S WEST ON FRIDAY. THEN UPPER 80S
EAST TO UPPER 90S WEST ON SATURDAY. SUNDAY...THE WARMEST
TEMPERATURES WILL SHIFT INTO THE EASTERN PORTION OF THE FORECAST
AREA WITH HIGHS IN THE LOW TO MID 90S. A COLD FRONT WILL MOVE INTO
THE WEST...COOLING TEMPERATURES BACK DOWN IN THE MID TO UPPER 80S.
WARM TEMPERATURES ALOFT SHOULD INHIBIT THUNDERSTORM CHANCES DURING
THE DAY ON SUNDAY.
THE COLD FRONT MOVES THROUGH THE FORECAST AREA SUNDAY NIGHT BUT WITH
CAPPING IN PLACE AND A RELATIVELY DRY ATMOSPHERE...PRECIPITATION
CHANCES WILL BE MEAGER. A MODEL BLEND BRINGS MAINLY SLIGHT CHANCE
POPS TO THE ENTIRE AREA SUNDAY NIGHT.
WITH THE FRONTAL PASSAGE THE MEAN UPPER RIDGE PASSES TO OUR EAST AND
WE REMAIN IN A BROAD SOUTHWEST UPPER LEVEL FLOW THROUGH AT LEAST THE
MIDDLE OF NEXT WEEK. ALTHOUGH DETERMINISTIC MODELS ARE NOT HINTING
AT ANY MAJOR SYSTEMS...WE CAN EXPECT DAILY ISOLATED TO SCATTERED
THUNDERSTORM CHANCES AS SHORTWAVES TRAVEL THROUGH THE SOUTHWEST
UPPER FLOW. TEMPERATURES ARE EXPECTED TO REMAIN AT OR A LITTLE ABOVE
NORMAL THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1237 PM CDT THU AUG 27 2015
MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD...WITH LOW
CONFIDENCE ON FOG FORMATION FRIDAY MORNING.
UPPER LEVEL CLOUDS CONTINUE TO STREAM OVER THE AREA WITH
SOME HAZE ORIGINATING FROM WILDFIRES IN THE PACIFIC NORTHWEST.
SHOWERS IN SOUTH DAKOTA ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE
MOVING EAST MAY BRING ISOLATED SHOWERS - POSSIBLY THUNDER - TO FAR
SOUTHERN NORTH DAKOTA THIS AFTERNOON INTO EARLY EVENING...BUT
WILL NOT MENTION FARTHER NORTH AT KDIK...KBIS...KJMS TAFS. LINGERING
LOW LEVEL MOISTURE - ESPECIALLY KMOT/KBIS/KDIK/KJMS MAY ALLOW MORE
FOG FORMATION FRIDAY MORNING...BUT WOULD LIKELY BE PATCHY AND
CONFIDENCE LOW AT THIS TIME TO MENTION IN LATER HOURS OF TAF
PERIOD - 11Z-14Z FRIDAY. DRY LOW LEVEL AIR BEGINS MOVING INTO KISN
AROUND 09Z AND SPREADS EAST ACROSS THE STATE FRIDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...ZH
LONG TERM...TWH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1000 AM CDT THU AUG 27 2015
.UPDATE...
ISSUED AT 959 AM CDT THU AUG 27 2015
BASED ON LATEST SHORT TERM GUIDANCE AND REGIONAL RADAR...THREAT
FOR ANY RAIN IN OUR FAR SOUTH APPEARS TO BE DECREASING AND THUS
WILL REMOVE POPS AND GO DRY IN SRN FCST AREA THIS AFTN-TONIGHT.
NO OTHER CHANGES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
FORECAST CHALLENGES CONCERN LOW END PCPN CHANCES ACROSS THE FAR
SOUTH AND NORTH AS WELL AS TEMPERATURES. MODELS IN REASONABLE
AGREEMENT THROUGH THE PERIOD.
CONVECTIVE COMPLEX OVER SD ASSOCIATED WITH WARM ADVECTION ZONE
AND ON NOSE OF LOW LEVEL JET AHEAD OF E WYO SHORT WAVE. SOME
WEAKER ECHOES FARTHER NORTH CLIPPING THE THE FAR SW FA HOWEVER
HAVE DOUBTS THAT ANY OF THIS REACHING THE GROUND. HRRR HANDLING
CURRENT CONVECTION WELL AND AS STRONGER CONVECTION OUTRUNS
INSTABILITY AXIS AND LOW LEVEL JET WEAKENS STORMS SHOULD WEAKEN AS
THEY CLIP THE ND/SD BORDER AREA LATER THIS MORNING. BASED ON THIS
SCENARIO WILL MAINTAIN SOME LOW POPS ACROSS THE FAR SOUTH. COULD
SEE SOME MORE DEVELOPMENT THIS AFTERNOON AS SURFACE LOW TRACKS
ACROSS NE HOWEVER MOST CAM/SHORT TERM MODEL GUIDANCE KEEPS THIS
JUST SOUTH OF THE BORDER. COOLEST READINGS LIKELY ACROSS THE FAR
SOUTH WITH MORE CLOUD COVER. OTHERWISE WITH FAIRLY WARM COLUMN AND
WARMER START TEMPERATURES SHOULD RECOVER TO AT OR A BIT ABOVE
AVERAGE.
SURFACE LOW WILL CONTINUE TO TRACK EAST ALONG THE NE/SD BORDER
AREA TO NEAR SUX BY FRIDAY MORNING. MODEL GUIDANCE CONTINUES TO
INDICATE NORTHERN FRINGE OF PCPN SHIELD POSSIBLY CLIPPING FAR
SOUTHERN FA SO WILL CONTINUE LOW POPS THERE. WITH LOW LEVEL
MOISTURE RECOVERY MINIMUM TEMPERATURES WILL BE WARMER.
LOW PULLS AWAY FRIDAY WITH COLUMN CONTINUING TO WARM. THIS SHOULD
ALLOW TEMPERATURES TO RECOVER TO ABOVE AVERAGE VALUES MOST AREAS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
WEAK SHORTWAVE ACROSS S MB FRIDAY NIGHT MAY BRING SOME PCPN
POTENTIAL TO NORTHERN AREAS. LACK OF INSTABILITY AND LOW LEVEL JET
SHOULD LIMIT COVERAGE AND ANY RESIDUAL CONVECTION SHOULD WEAKEN
EARLY SATURDAY.
COLUMN CONTINUES TO WARM SATURDAY SO WELL ABOVE AVERAGE
TEMPERATURES EXPECTED WITH WESTERN AREAS APPROACHING 90.
THE EXTENDED PERIOD STARTS WITH UPPER LEVEL RIDGING OVER THE NRN
PLAINS ALLOWING WARMER TEMPS...MAINLY IN THE 80S...TO REMAIN OVER
THE AREA. THE PATTERN BEGINS TO CHANGE BY MONDAY AS AN UPPER TROF
BEGINS TO DEEPEN AND SHIFT OVER THE INTERMOUNTAIN WEST...BRINGING SW
FLOW ALOFT TO THE AREA. A SERIES OF UPPER DISTURBANCES ARE EXPECTED
TO PROPAGATE THROUGH THE FLOW...BRINGING INCREASED CHANCES FOR
SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA LATE IN THE PERIOD.
TEMPERATURES LATE IN THE PERIOD ARE EXPECTED TO COOL A BIT...TO MORE
SEASONAL VALUES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM CDT THU AUG 27 2015
MID/UPPER LEVEL CLOUDS ACROSS THE SOUTHERN HALF OF THE FA
OTHERWISE VFR ACROSS THE FORECAST AREA THROUGH THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...VOELKER
LONG TERM...HOPKINS/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
951 AM CDT THU AUG 27 2015
.UPDATE...
ISSUED AT 949 AM CDT THU AUG 27 2015
ITERATIONS OF THE HRRR MODEL EACH HOUR INDICATE WANING CHANCES FOR
ANY SHOWERS ACROSS THE SOUTHERN TIER OF COUNTIES. UPPER LEVEL
DISTURBANCE ACROSS SOUTH DAKOTA WAS ASSOCIATED WITH ONGOING
SCATTERED SHOWERS IN SOUTH DAKOTA. HAVE TRIMMED CHANCES IN NORTH
DAKOTA TO SLIGHT CHANCE. FOR THE AFTERNOON HOWEVER...KEPT CHANCE
MENTIONS IN THE SOUTH WITH MODELS INDICATING AFTERNOON CAPE AND
PLENTY OF LOW LEVEL MOISTURE AVAILABLE...WITH DEWPOINTS IN THE UPPER
50S AND LOWER 60S ACROSS THE REGION. PATCHY FOG WAS DISSIPATING
ACROSS THE REGION...THUS THE EARLIER UPDATE TO ADD PATCHY FOG
UNTIL AROUND 10 AM CDT LOOKS ON TRACK.
OTHERWISE ONLY HOURLY TRENDS IN TEMPERATURES AND WINDS WERE UPDATED
WITH NO CHANGES IN THE OVERALL EXPECTED TEMPS THIS AFTERNOON.
UPDATE ISSUED AT 627 AM CDT THU AUG 27 2015
CONVECTION TRACKING SOUTHEAST ACROSS EASTERN SOUTH DAKOTA.
UPSTREAM NEXT SHORTWAVE IS TRACKING ACROSS WESTERN WYOMING. STILL
A LITTLE CONVECTIVE DEBRIS LINGERING ACROSS NORTHERN SOUTH DAKOTA
BUT SHOULD BE RELATIVELY QUIET ACROSS SOUTHERN NORTH DAKOTA FOR
THE NEXT FEW HOURS. DID KEEP SOME SLIGHT CHANCE POPS OVER THE FAR
SOUTH EARLY THIS MORNING...THEN BEGAN INCREASING POPS ACROSS THE
SOUTH MID TO LATE MORNING. STILL JUST LOOKING AT CHC POPS FAR
SOUTH TODAY TO SLIGHT CHANCE UP TO THE I94 CORRIDOR. OTHERWISE NO
SIGNIFICANT CHANGES TO THE GOING FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 238 AM CDT THU AUG 27 2015
WARMING TEMPERATURES AND ISOLATED THUNDERSTORM POTENTIAL IN THE
SOUTH HIGHLIGHT THE SHORT TERM.
AN UPPER LEVEL LOW WAS LOCATED OVER NORTHERN WYOMING...TRIGGERING
WIDESPREAD SHOWERS AND THUNDERSTORMS OVER CENTRAL SOUTH DAKOTA
EARLY THIS MORNING. AS AN ASSOCIATED SURFACE LOW DEEPENS ON THE
SOUTH DAKOTA NEBRASKA BORDER...PRECIPITATION SHOULD
EXPAND...NUDGING INTO THE COUNTY WARNING AREA LATER THIS MORNING
AND INTO THIS AFTERNOON. THE BEST CHANCES FOR A FEW SHOWERS AND
THUNDERSTORMS WILL BE IN OUR MOST SOUTHERN ZONES...SOUTH OF
INTERSTATE 94. WITH MEAGER INSTABILITY AND WEAK DEEP LAYER SHEAR
FORECAST...SEVERE WEATHER DOES NOT APPEAR TO BE A THREAT. THURSDAY
WILL ALSO FEATURE WARMER TEMPERATURES AS THE UPPER 80S CREEP INTO
THE WEST.
ANOTHER SHORTWAVE WILL APPROACH OUR NORTHWEST COUNTIES THURSDAY
NIGHT...BRINGING A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM TO
THE NORTHWEST AND NORTH CENTRAL PARTS OF THE STATE. HOWEVER...AT
THIS TIME IT APPEARS THAT THE STRONGEST FORCING MECHANISMS WILL
REMAIN NORTH OF THE INTERNATIONAL BORDER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 238 AM CDT THU AUG 27 2015
WARM TEMPERATURES AND PERIODIC THUNDERSTORM CHANCES HIGHLIGHT THE
EXTENDED FORECAST PERIOD.
DETERMINISTIC AND ENSEMBLE MODELS ARE IN GOOD AGREEMENT OVER THE
NORTHERN PLAINS THROUGH THE LONG TERM PERIOD AS A MEAN WESTERN CONUS
UPPER LEVEL RIDGE AMPLIFIES OVER THE CENTRAL U.S OVER THE UPCOMING
WEEKEND...THEN TRANSLATES TO THE EASTERN CONUS NEXT WEEK. THIS WILL
BRING ABOVE NORMAL TEMPERATURES AND LIMITED PRECIPITATION CHANCES TO
WESTERN AND CENTRAL NORTH DAKOTA FRIDAY THROUGH SUNDAY. AN ISOLATED
THUNDERSTORM CAN NOT BE COMPLETELY RULED OUT FRIDAY ALONG THE
CANADIAN BORDER ON THE PERIPHERY OF THE BUILDING RIDGE. BUT WILL
KEEP A DRY FORECAST FOR NOW. FORECAST HIGH ARE EXPECTED TO RANGE
FROM THE MID 80S EAST TO LOWER 90S WEST ON FRIDAY. THEN UPPER 80S
EAST TO UPPER 90S WEST ON SATURDAY. SUNDAY...THE WARMEST
TEMPERATURES WILL SHIFT INTO THE EASTERN PORTION OF THE FORECAST
AREA WITH HIGHS IN THE LOW TO MID 90S. A COLD FRONT WILL MOVE INTO
THE WEST...COOLING TEMPERATURES BACK DOWN IN THE MID TO UPPER 80S.
WARM TEMPERATURES ALOFT SHOULD INHIBIT THUNDERSTORM CHANCES DURING
THE DAY ON SUNDAY.
THE COLD FRONT MOVES THROUGH THE FORECAST AREA SUNDAY NIGHT BUT WITH
CAPPING IN PLACE AND A RELATIVELY DRY ATMOSPHERE...PRECIPITATION
CHANCES WILL BE MEAGER. A MODEL BLEND BRINGS MAINLY SLIGHT CHANCE
POPS TO THE ENTIRE AREA SUNDAY NIGHT.
WITH THE FRONTAL PASSAGE THE MEAN UPPER RIDGE PASSES TO OUR EAST AND
WE REMAIN IN A BROAD SOUTHWEST UPPER LEVEL FLOW THROUGH AT LEAST THE
MIDDLE OF NEXT WEEK. ALTHOUGH DETERMINISTIC MODELS ARE NOT HINTING
AT ANY MAJOR SYSTEMS...WE CAN EXPECT DAILY ISOLATED TO SCATTERED
THUNDERSTORM CHANCES AS SHORTWAVES TRAVEL THROUGH THE SOUTHWEST
UPPER FLOW. TEMPERATURES ARE EXPECTED TO REMAIN AT OR A LITTLE ABOVE
NORMAL THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 627 AM CDT THU AUG 27 2015
MID TO UPPER LEVEL CLOUDS CONTINUE TO STREAM OVER THE AREA WITH
SOME HAZE ORIGINATING FROM WILDFIRES IN THE PACIFIC NORTHWEST. A
BAND OF SPOTTY SHOWERS WAS LOCATED JUST SOUTH OF KJMS AND MAY
PROVIDE A SPRINKLE OR TWO THROUGH 18Z. CLOUDS SHOULD HANG AROUND
UNTIL LATE THURSDAY AFTERNOON OR EVENING...CLEARING FROM WEST TO
EAST. VFR CEILINGS AND VISIBILITIES SHOULD PREVAIL THROUGHOUT THE
PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...ZH
LONG TERM...TWH
AVIATION...ZH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
643 AM CDT THU AUG 27 2015
.UPDATE...
ISSUED AT 637 AM CDT THU AUG 27 2015
CONVECTION ACROSS SD PROPAGATING SE AND ECHOES OVER THE SW FA
DIMINISHING. BASED ON FAVORED SHORT TERM MODEL GUIDANCE LOW
CONFIDENCE THAT THE SOUTHERN FA WILL GET ANY PCPN TODAY. KEPT THE
MORNING DRY BUT FOR NOW HELD ON TO LOW POPS ACROSS THE FAR SOUTH
THIS AFTERNOON. NO OTHER SIGNIFICANT CHANGES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
FORECAST CHALLENGES CONCERN LOW END PCPN CHANCES ACROSS THE FAR
SOUTH AND NORTH AS WELL AS TEMPERATURES. MODELS IN REASONABLE
AGREEMENT THROUGH THE PERIOD.
CONVECTIVE COMPLEX OVER SD ASSOCIATED WITH WARM ADVECTION ZONE
AND ON NOSE OF LOW LEVEL JET AHEAD OF E WYO SHORT WAVE. SOME
WEAKER ECHOES FARTHER NORTH CLIPPING THE THE FAR SW FA HOWEVER
HAVE DOUBTS THAT ANY OF THIS REACHING THE GROUND. HRRR HANDLING
CURRENT CONVECTION WELL AND AS STRONGER CONVECTION OUTRUNS
INSTABILITY AXIS AND LOW LEVEL JET WEAKENS STORMS SHOULD WEAKEN AS
THEY CLIP THE ND/SD BORDER AREA LATER THIS MORNING. BASED ON THIS
SCENARIO WILL MAINTAIN SOME LOW POPS ACROSS THE FAR SOUTH. COULD
SEE SOME MORE DEVELOPMENT THIS AFTERNOON AS SURFACE LOW TRACKS
ACROSS NE HOWEVER MOST CAM/SHORT TERM MODEL GUIDANCE KEEPS THIS
JUST SOUTH OF THE BORDER. COOLEST READINGS LIKELY ACROSS THE FAR
SOUTH WITH MORE CLOUD COVER. OTHERWISE WITH FAIRLY WARM COLUMN AND
WARMER START TEMPERATURES SHOULD RECOVER TO AT OR A BIT ABOVE
AVERAGE.
SURFACE LOW WILL CONTINUE TO TRACK EAST ALONG THE NE/SD BORDER
AREA TO NEAR SUX BY FRIDAY MORNING. MODEL GUIDANCE CONTINUES TO
INDICATE NORTHERN FRINGE OF PCPN SHIELD POSSIBLY CLIPPING FAR
SOUTHERN FA SO WILL CONTINUE LOW POPS THERE. WITH LOW LEVEL
MOISTURE RECOVERY MINIMUM TEMPERATURES WILL BE WARMER.
LOW PULLS AWAY FRIDAY WITH COLUMN CONTINUING TO WARM. THIS SHOULD
ALLOW TEMPERATURES TO RECOVER TO ABOVE AVERAGE VALUES MOST AREAS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
WEAK SHORTWAVE ACROSS S MB FRIDAY NIGHT MAY BRING SOME PCPN
POTENTIAL TO NORTHERN AREAS. LACK OF INSTABILITY AND LOW LEVEL JET
SHOULD LIMIT COVERAGE AND ANY RESIDUAL CONVECTION SHOULD WEAKEN
EARLY SATURDAY.
COLUMN CONTINUES TO WARM SATURDAY SO WELL ABOVE AVERAGE
TEMPERATURES EXPECTED WITH WESTERN AREAS APPROACHING 90.
THE EXTENDED PERIOD STARTS WITH UPPER LEVEL RIDGING OVER THE NRN
PLAINS ALLOWING WARMER TEMPS...MAINLY IN THE 80S...TO REMAIN OVER
THE AREA. THE PATTERN BEGINS TO CHANGE BY MONDAY AS AN UPPER TROF
BEGINS TO DEEPEN AND SHIFT OVER THE INTERMOUNTAIN WEST...BRINGING SW
FLOW ALOFT TO THE AREA. A SERIES OF UPPER DISTURBANCES ARE EXPECTED
TO PROPAGATE THROUGH THE FLOW...BRINGING INCREASED CHANCES FOR
SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA LATE IN THE PERIOD.
TEMPERATURES LATE IN THE PERIOD ARE EXPECTED TO COOL A BIT...TO MORE
SEASONAL VALUES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM CDT THU AUG 27 2015
MID/UPPER LEVEL CLOUDS ACROSS THE SOUTHERN HALF OF THE FA
OTHERWISE VFR ACROSS THE FORECAST AREA THROUGH THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...VOELKER
LONG TERM...HOPKINS/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
322 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
FORECAST CHALLENGES CONCERN LOW END PCPN CHANCES ACROSS THE FAR
SOUTH AND NORTH AS WELL AS TEMPERATURES. MODELS IN REASONABLE
AGREEMENT THROUGH THE PERIOD.
CONVECTIVE COMPLEX OVER SD ASSOCIATED WITH WARM ADVECTION ZONE
AND ON NOSE OF LOW LEVEL JET AHEAD OF E WYO SHORT WAVE. SOME
WEAKER ECHOES FARTHER NORTH CLIPPING THE THE FAR SW FA HOWEVER
HAVE DOUBTS THAT ANY OF THIS REACHING THE GROUND. HRRR HANDLING
CURRENT CONVECTION WELL AND AS STRONGER CONVECTION OUTRUNS
INSTABILITY AXIS AND LOW LEVEL JET WEAKENS STORMS SHOULD WEAKEN AS
THEY CLIP THE ND/SD BORDER AREA LATER THIS MORNING. BASED ON THIS
SCENARIO WILL MAINTAIN SOME LOW POPS ACROSS THE FAR SOUTH. COULD
SEE SOME MORE DEVELOPMENT THIS AFTERNOON AS SURFACE LOW TRACKS
ACROSS NE HOWEVER MOST CAM/SHORT TERM MODEL GUIDANCE KEEPS THIS
JUST SOUTH OF THE BORDER. COOLEST READINGS LIKELY ACROSS THE FAR
SOUTH WITH MORE CLOUD COVER. OTHERWISE WITH FAIRLY WARM COLUMN AND
WARMER START TEMPERATURES SHOULD RECOVER TO AT OR A BIT ABOVE
AVERAGE.
SURFACE LOW WILL CONTINUE TO TRACK EAST ALONG THE NE/SD BORDER
AREA TO NEAR SUX BY FRIDAY MORNING. MODEL GUIDANCE CONTINUES TO
INDICATE NORTHERN FRINGE OF PCPN SHIELD POSSIBLY CLIPPING FAR
SOUTHERN FA SO WILL CONTINUE LOW POPS THERE. WITH LOW LEVEL
MOISTURE RECOVERY MINIMUM TEMPERATURES WILL BE WARMER.
LOW PULLS AWAY FRIDAY WITH COLUMN CONTINUING TO WARM. THIS SHOULD
ALLOW TEMPERATURES TO RECOVER TO ABOVE AVERAGE VALUES MOST AREAS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CDT THU AUG 27 2015
WEAK SHORTWAVE ACROSS S MB FRIDAY NIGHT MAY BRING SOME PCPN
POTENTIAL TO NORTHERN AREAS. LACK OF INSTABILITY AND LOW LEVEL JET
SHOULD LIMIT COVERAGE AND ANY RESIDUAL CONVECTION SHOULD WEAKEN
EARLY SATURDAY.
COLUMN CONTINUES TO WARM SATURDAY SO WELL ABOVE AVERAGE
TEMPERATURES EXPECTED WITH WESTERN AREAS APPROACHING 90.
THE EXTENDED PERIOD STARTS WITH UPPER LEVEL RIDGING OVER THE NRN
PLAINS ALLOWING WARMER TEMPS...MAINLY IN THE 80S...TO REMAIN OVER
THE AREA. THE PATTERN BEGINS TO CHANGE BY MONDAY AS AN UPPER TROF
BEGINS TO DEEPEN AND SHIFT OVER THE INTERMOUNTAIN WEST...BRINGING SW
FLOW ALOFT TO THE AREA. A SERIES OF UPPER DISTURBANCES ARE EXPECTED
TO PROPAGATE THROUGH THE FLOW...BRINGING INCREASED CHANCES FOR
SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA LATE IN THE PERIOD.
TEMPERATURES LATE IN THE PERIOD ARE EXPECTED TO COOL A BIT...TO MORE
SEASONAL VALUES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1138 PM CDT WED AUG 26 2015
VFR CONDITIONS CONTINUE AS MID AND HIGH CLOUDS MOVE INTO
SOUTHEASTERN NORTH DAKOTA FROM THE WEST. WINDS WILL REMAIN OUT OF
THE SOUTHEAST AT LESS THAN 10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...HOPKINS/VOELKER
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1139 PM CDT WED AUG 26 2015
.UPDATE...
ISSUED AT 1138 PM CDT WED AUG 26 2015
LOWERED LOWS A FEW DEGREES IN OUR USUAL COOL SPOTS OF THE
NORTHWESTERN CWA AND NEAR FOSSTON...TEMPS HAVE BEEN FALLING INTO
THE LOW 50S ALREADY THERE AND SHOULD GET DOWN INTO THE UPPER 40S
BY MORNING. OTHERWISE NO MAJOR CHANGES.
UPDATE ISSUED AT 941 PM CDT WED AUG 26 2015
ADJUSTED CLOUD COVER FOR CURRENT SATELLITE TRENDS. AT THIS POINT
IT SEEMS THAT MOST OF THE THICKER CLOUDS WILL BE IN THE SOUTH AS A
WEAK WAVE MOVES THROUGH SOUTH DAKOTA OVERNIGHT. TWEAKED TEMPS A
BIT AS SOME HAVE FALLEN A BIT FASTER THAN EXPECTED. STILL
EXPECTING LOWS TO RANGE FROM THE UPPER 40S TO MID 50S.
UPDATE ISSUED AT 644 PM CDT WED AUG 26 2015
INCREASED CLOUDS A BIT WITH SOME MID AND HIGH LEVEL COVERAGE
MOVING INTO THE WESTERN CWA. NO OTHER CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 332 PM CDT WED AUG 26 2015
500 MB UPPER RIDGE BUILDING FROM NEW MEXICO INTO ERN WYOMING.
SEVERAL SHORT WAVES SEEN MOVING ON TOP OF UPPER RIDGE INTO
WRN/CNTRL ND AND SOUTH DAKOTA TODAY. SOME BANDS OF MID AND HIGH
LEVEL CLOUD COVER WITH THESE WAVES AND NOT SURE IF MODELS ARE
HANDLING THESE CLOUDS BANDS ALL THAT GOOD. ONE CLOUD BAND NORTH OF
WILLISTON TO RUGBY MOVING EAST-SOUTHEAST AND THE OTHER SOUTH OF
WATFORD CITY TO BISMARCK MOVING SOUTHEAST. THE NRN CLOUD BAND ISNT
HANDLED BY THE MODELS WELL AT ALL AS THEY WANT TO DRY UP THE
CLOUDS TOO MUCH IT SEEMS. OTHER CLOUD BAND HANDLED OK BY HRRR IN
HAVING A FEW SPRINKLES INTO SCNTRL ND EARLY EVENING. LATEST HRRR
HAS A FEW RW-- INTO FAR SE ND AS WELL OVERNIGHT. WILL MAINTAIN DRY
FCST AND LATER SHIFTS CAN ADD RW-- HAS NEEDED. IT WOULD BE VERY
VERY MINOR.
WARMER THAN THE LAST FEW NIGHTS AS SOUTHERLY WINDS HOLD UP ENOUGH
FOR MORE MIXING.
MAIN SHORT WAVE WILL MOVE EAST AND TEMPORARILY SQUASH THE RIDGE
AND MOVE THRU SRN SD INTO SRN MN/NRN IA LATER THURSDAY AFTERNOON
AND NIGHT. NRN EDGE OF ANY PRECIP WILL JUST SKIRT THE FAR SRN FCST
AREA SO CONFINED POPS TO THAT AREA ONLY. A FEW DEGREES WARMER ON
THURSDAY AS WELL.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 332 PM CDT WED AUG 26 2015
A SHORT WAVE MOVING EAST THRU SRN CANADA WILL BRING A RISK OF A
T-STORM TO THE CANADIAN BORDER REGION FRI AFTN-EVE.. BIT BETTER
RISK IN LAKE OF THE WOODS AREA FRI EVE. OTHERWISE GETTING WARMER
STILL AS UPPER AIR RIDGE BEINGS TO BUILD NORTHWARD. UPPER AIR
BUILDS INTO NORTH DAKOTA SATURDAY AS HIGH TEMPS CLIMB WELL INTO
THE 80S. IT WILL BE DRY.
SATURDAY NIGHT-WEDNESDAY...A VERY WARM AND FAIRLY QUIET PERIOD IS
EXPECTED. A WEST TO SOUTHWEST FLOW PATTERN ALOFT WILL PERSIST OVER
THE N PLAINS WITH THE MEAN UPPER RIDGE OVER THE EASTERN CONUS AND
PERSISTENT TROUGHING OVER THE PACIFIC NORTHWEST. WITH THE UPPER JET
REMAINING NORTH INTO CANADA...ORGANIZED PRECIP CHANCES LOOK LOW.
SOME UPPER LEVEL ENERGY WILL SLIDE NORTH ACROSS CENTRAL CANADA EARLY
IN THE WEEK...POSSIBLY DRAGGING A SFC TROUGH INTO THE AREA WITH
MAYBE A FEW STORMS. OTHERWISE...ANY OTHER STORMS WILL DEPEND ON
SUBTLE FORCING WITH WEAK UPPER WAVES. TEMPS WILL REMAIN ABOVE
AVERAGE...WITH HIGHS GENERALLY IN THE 80S TO PERHAPS LOW 90S IN
SPOTS...AND LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1138 PM CDT WED AUG 26 2015
VFR CONDITIONS CONTINUE AS MID AND HIGH CLOUDS MOVE INTO
SOUTHEASTERN NORTH DAKOTA FROM THE WEST. WINDS WILL REMAIN OUT OF
THE SOUTHEAST AT LESS THAN 10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...RIDDLE
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1054 PM EDT FRI AUG 28 2015
.SYNOPSIS...
WARMING TREND THIS WEEKEND WITH ISOLATED AFTERNOON SHOWER IN THE
MOUNTAINS. MORE HUMID SUNDAY INTO NEXT WEEK...WITH A BETTER CHANCE
FOR SHOWERS...ESPECIALLY MONDAY INTO TUESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
1100 PM UPDATE...
FCST REMAINS ON TRACK OUTSIDE SLIGHTLY FASTER DROP ON
TEMPERATURES NRN PORTION OF FCST AREA.
800 PM UPDATE...
FCST ON TRACK WITH AFTERNOON CU DISSIPATED.
PREV DISCN...
ANOTHER QUIET WEATHER DAY WITH CU FORMING OVER THE HIGHER
TERRAIN...AND ALSO IN SE OHIO. NAM CONTINUES TO SHOW SHOWERS
DEVELOPING OVER THE MOUNTAINS TODAY. DID LEAVE AN ISOLATED SHOWER
IN...BUT THINK THE HRRR HAS A BETTER SOLUTION KEEPING SHOWERS EAST
OF CWA WHERE BETTER DEVELOPED CU ARE SHOWING ON SATELLITE.
HIGH PRESSURE DRIFTS NORTHEAST TONIGHT...AND MODELS TRYING TO
SHOW SOME CLOUDS MOVING IN ACROSS THE SOUTH LATE TONIGHT AND
DRIFTING NORTH THROUGH THE DAY. ANTICIPATE VALLEY FOG BEGINNING TO
FORM...BUT MAY BE TEMPERED BY CLOUDS...ESPECIALLY ACROSS THE
SOUTH.
WITH A BIT MORE MOISTURE COMING IN SATURDAY...THINK UPSLOPE FLOW
SHOULD LEAD TO AN ISOLATED SHOWER OR TSTORM ACROSS THE MOUNTAINS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
THE TRANSITION FROM WEAK UPPER RIDGING TO WEAK UPPER TROUGHING
OVER THE EASTERN U.S...WHICH WILL ALLOW AN UPPER DISTURBANCE TO
EJECT NORTHEASTWARD OUT OF THE NORTHERN GULF OF MEXICO...LOOKS TO
BE DELAYED BY ABOUT 24 HOURS. THUS...SUNDAY AFTERNOON CONVECTION
LOOKS TO BE MAINLY WIDELY SCATTERED AND OVER THE MOUNTAINS.
LOOK FOR TEMPERATURES IN THE UPPER 80S WITH MORE HUMID
CONDITIONS SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
WITH VERY WARM AND MOIST AIR IN PLACE...THE AFOREMENTIONED UPPER
DISTURBANCE LIFTING NORTHEAST ACROSS THE AREA MONDAY INTO
TUESDAY WILL BRING A BETTER CHANCE OF SHOWERS AND A STORM...ESPECIALLY
OVER THE MOUNTAINS. UPPER RIDGING WILL AGAIN BUILD OVER THE AREA
FOR THE MIDDLE AND LATER PART OF NEXT WEEK...WITH VERY WARM AND
HUMID CONDITIONS PREVAILING...BUT LITTLE RAINFALL. TEMPERATURES
WILL GENERALLY BE NEAR 90 DEGREES EACH DAY.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
DENSE VALLEY FOG EXPECTED AGAIN OVERNIGHT ALTHOUGH PATCHY STRATOCU
MAY HINDER IT A BIT. A LIGHT SE FLOW MAY ALSO HINDER FOG ALONG THE
OHIO RIVER.
EXPECT ANOTHER VFR DAY SAT ONCE THE FOG IS GONE. AN AFTERNOON
SHOWER MAY POP UP IN THE MOUNTAINS.
SFC FLOW OVERNIGHT WILL BE CALM TO LIGHT SE...AND THEN LIGHT S TO
SW ON SAT. FLOW ALOFT WILL CONTINUE LIGHT SW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING/INTENSITY OF DENSE RIVER VALLEY FOG COULD
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.
DATE SAT 08/29/15
UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
EDT 1HRLY 23 00 01 02 03 04 05 06 07 08 09 10
CRW CONSISTENCY H H M M M L L L L L M H
HTS CONSISTENCY H H M L L L L L L L M H
BKW CONSISTENCY H H H H H H H H M M M H
EKN CONSISTENCY H M M L L L L L L L L H
PKB CONSISTENCY H H H H H M L L L L M H
CKB CONSISTENCY H H H H M M L M M M H H
AFTER 00Z SUNDAY...
SPOTTY IFR IN RIVER VALLEY FOG POSSIBLE LATE SATURDAY INTO EARLY
SUNDAY DEPENDING ON CLOUDS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/JMV/MZ
NEAR TERM...TRM/MZ
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
756 PM EDT FRI AUG 28 2015
.SYNOPSIS...
WARMING TREND THIS WEEKEND WITH ISOLATED AFTERNOON SHOWER IN THE
MOUNTAINS. MORE HUMID SUNDAY INTO NEXT WEEK...WITH A BETTER CHANCE
FOR SHOWERS...ESPECIALLY MONDAY INTO TUESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
800 PM UPDATE...
FCST ON TRACK WITH AFTERNOON CU DISSIPATED.
PREV DISCN...
ANOTHER QUIET WEATHER DAY WITH CU FORMING OVER THE HIGHER
TERRAIN...AND ALSO IN SE OHIO. NAM CONTINUES TO SHOW SHOWERS
DEVELOPING OVER THE MOUNTAINS TODAY. DID LEAVE AN ISOLATED SHOWER
IN...BUT THINK THE HRRR HAS A BETTER SOLUTION KEEPING SHOWERS EAST
OF CWA WHERE BETTER DEVELOPED CU ARE SHOWING ON SATELLITE.
HIGH PRESSURE DRIFTS NORTHEAST TONIGHT...AND MODELS TRYING TO
SHOW SOME CLOUDS MOVING IN ACROSS THE SOUTH LATE TONIGHT AND
DRIFTING NORTH THROUGH THE DAY. ANTICIPATE VALLEY FOG BEGINNING TO
FORM...BUT MAY BE TEMPERED BY CLOUDS...ESPECIALLY ACROSS THE
SOUTH.
WITH A BIT MORE MOISTURE COMING IN SATURDAY...THINK UPSLOPE FLOW
SHOULD LEAD TO AN ISOLATED SHOWER OR TSTORM ACROSS THE MOUNTAINS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
THE TRANSITION FROM WEAK UPPER RIDGING TO WEAK UPPER TROUGHING
OVER THE EASTERN U.S...WHICH WILL ALLOW AN UPPER DISTURBANCE TO
EJECT NORTHEASTWARD OUT OF THE NORTHERN GULF OF MEXICO...LOOKS TO
BE DELAYED BY ABOUT 24 HOURS. THUS...SUNDAY AFTERNOON CONVECTION
LOOKS TO BE MAINLY WIDELY SCATTERED AND OVER THE MOUNTAINS.
LOOK FOR TEMPERATURES IN THE UPPER 80S WITH MORE HUMID
CONDITIONS SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
WITH VERY WARM AND MOIST AIR IN PLACE...THE AFOREMENTIONED UPPER
DISTURBANCE LIFTING NORTHEAST ACROSS THE AREA MONDAY INTO
TUESDAY WILL BRING A BETTER CHANCE OF SHOWERS AND A STORM...ESPECIALLY
OVER THE MOUNTAINS. UPPER RIDGING WILL AGAIN BUILD OVER THE AREA
FOR THE MIDDLE AND LATER PART OF NEXT WEEK...WITH VERY WARM AND
HUMID CONDITIONS PREVAILING...BUT LITTLE RAINFALL. TEMPERATURES
WILL GENERALLY BE NEAR 90 DEGREES EACH DAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
DENSE VALLEY FOG EXPECTED AGAIN OVERNIGHT ALTHOUGH PATCHY STRATOCU
MAY HINDER IT A BIT. A LIGHT SE FLOW MAY ALSO HINDER FOG ALONG THE
OHIO RIVER.
EXPECT ANOTHER VFR DAY SAT ONCE THE FOG IS GONE. AN AFTERNOON
SHOWER MAY POP UP IN THE MOUNTAINS.
SFC FLOW OVERNIGHT WILL BE CALM TO LIGHT SE...AND THEN LIGHT S TO
SW ON SAT. FLOW ALOFT WILL CONTINUE LIGHT SW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING/INTENSITY OF DENSE RIVER VALLEY FOG COULD
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.
DATE SAT 08/29/15
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H M M M L L L L
HTS CONSISTENCY H H H H H M L L L L L L
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H M M L L L L L L
PKB CONSISTENCY H H H H H H H H M L L L
CKB CONSISTENCY H H H H H H H M M L M M
AFTER 00Z SUNDAY...
SPOTTY IFR IN RIVER VALLEY FOG POSSIBLE LATE SATURDAY INTO EARLY
SUNDAY DEPENDING ON CLOUDS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/JMV/MZ
NEAR TERM...TRM/MZ
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS NORMAN OK
610 PM CDT FRI AUG 28 2015
.AVIATION...
MAINLY MID/HIGH CLOUDS EXPECTED OVERNIGHT WITH A GRADUAL SHIFT TO
THE SOUTH OF THE TAF SITES BY MIDDAY SATURDAY. THERE WILL BE AREAS
OF LIGHT RAIN AND SPRINKLES... BUT OTHER THAN A COUPLE OF HOURS AT
SPS WILL NOT MENTION. WEAK FRONT THAT CONT TO LINGER IN NORTHWEST
OKLAHOMA WILL MAKE SOME PROGRESS SOUTH AND EAST OVERNIGHT INTO
SATURDAY MORNING WITH A SHIFT TO NORTH WINDS BEHIND IT. HOWEVER...
SPEEDS ARE EXPECTED TO REMAIN BELOW 12KTS.
30
&&
.PREV DISCUSSION... /ISSUED 309 PM CDT FRI AUG 28 2015/
.DISCUSSION...
DETERMINING RAIN CHANCES TONIGHT IS THE PRIMARY FORECAST CHALLENGE
OF THE DAY.
OVERALL...SLIGHTLY LOWERED RAIN CHANCES THROUGH TONIGHT DUE TO
WEAK FORCING FOR PRODUCING RAINFALL. DID NOT GO ABOVE 20 PERCENT
IN ANY GIVEN LOCATION.
THROUGH MIDNIGHT TONIGHT...THINK A FEW LIGHT SHOWERS AND
SPRINKLES WILL CONTINUE WHERE THERE IS SOME MID LEVEL MOISTURE
CONVERGENCE...GENERALLY NEAR AN ALTUS TO NORMAN TO CHANDLER LINE.
A FEW THUNDERSTORMS ARE POSSIBLE AS WELL MAINLY NEAR AN HIGHER
INSTABILITY AXIS EXISTS FROM HOLLIS TO CLINTON TO CHEROKEE. ANY
STORM IS EXPECTED TO BE SUBSEVERE WITH PERHAPS A FEW STRONG WIND
GUSTS UP TO 50 MPH AND SOME LOCALIZED DOWNPOURS. PRECIPITATION
COVERAGE MAY DIMINISH AFTER SUNSET DUE TO THE LOSS OF DAYTIME
HEATING. RAINFALL SHOULD RAIN SPARSE AND UNDER 0.10 INCH IN MOST
LOCATIONS.
AFTER MIDNIGHT TONIGHT...A FEW SHOWERS AND PERHAPS A FEW
THUNDERSTORMS MAY CONTINUE ACROSS THE AREA...MAINLY SOUTH OF A ELK
CITY TO PONCA CITY LINE. LATEST RUC13 SUGGESTED THAT THE 850 MB
JET MAY INCREASE OVER WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA
WHICH MAY ALLOW FOR INCREASED COVERAGE OF RAIN. HOWEVER...
INSTABILITY MAY BE LACKING. THUS...KEPT 20 PERCENT CHANCES IN
THESE AREAS.
SATURDAY...OVERALL...PARTLY TO MOSTLY SUNNY AND DRY WEATHER CAN BE
EXPECTED. WOULD NOT BE COMPLETELY SURPRISED IF A STRAY SHOWER OR STORM
OCCURRED SOUTH OF A QUANAH TEXAS TO OKLAHOMA CITY TO CHANDLER
LINE...BUT DID NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
HIGHS WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE...MAINLY IN THE 90S.
SATURDAY NIGHT THROUGH FRIDAY...A DRY WEATHER PATTERN IS FORECAST
WITH NEAR OR ABOVE AVERAGE TEMPERATURES. THERE ARE SOME MODEL
DIFFERENCES MAINLY IN REGARDS TO THE LOCATION AND PROGRESSION A
MID/UPPER TROUGH SOMEWHERE OVER THE SOUTHERN PLAINS OR
SOUTHEASTERN U.S. AT THIS TIME...THINK THE DEEPEST MOISTURE AND
HIGHER RAIN CHANCES WILL STAY EAST OF OKLAHOMA AND NORTH
TEXAS...BUT CONFIDENCE IS RATHER LOW.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 92 67 92 / 20 10 0 0
HOBART OK 68 96 66 96 / 20 10 10 0
WICHITA FALLS TX 74 98 68 98 / 20 10 10 10
GAGE OK 63 92 60 93 / 10 0 0 0
PONCA CITY OK 67 89 64 91 / 20 10 10 0
DURANT OK 72 94 70 95 / 20 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
104 PM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM CDT THU AUG 27 2015
AN MCS HAS DEVELOPED OVER WESTERN AND CENTRAL SOUTH DAKOTA AND WILL
HAS BEGUN MOVING INTO OUR WESTERN FORECAST AREA. THIS COMPLEX HAS A
HISTORY OF VERY STRONG WINDS WITH MIDLAND SD REPORTING 79 MPH GUSTS
AS IT MOVED OVERHEAD. GIVEN THAT THIS COMPLEX IS SHOWING SIGNS OF
WEAKENING AS IT MOVES EAST...THINK THAT THE SEVERE WIND THREAT WILL
BE GREATEST IN OUR SOUTH CENTRAL SD COUNTIES. HRRR SUGGESTS THAT IT
WILL SIGNIFICANTLY WEAKEN BY THE TIME IT HEADS EAST OF THE JAMES
RIVER.
THINK THIS THIS INITIAL WAVE OF SHOWERS AND THUNDERSTORMS WILL
APPROACH I29 SHORTLY AFTER SUNRISE AND WEAKEN FURTHER AS IT MOVES
THROUGH SW MN AND NW IA THROUGH MIDDAY. THERE WILL LIKELY BE SOME
SORT OF BREAK IN ACTIVITY BEHIND THIS COMPLEX...BUT THIS WILL BE
SHORT LIVED. SURFACE LOW PRESSURE SLIDING EASTWARD ALONG THE
MISSOURI RIVER AHEAD OF THE MAIN UPPER LOW DIGGING INTO CENTRAL
SD...WILL IGNITE FURTHER CONVECTION LATER THIS AFTERNOON AS WARM AIR
AND MOISTURE CONTINUES TO ADVECT INTO THE REGION. THIS INITIAL
ACTIVITY WILL LIKELY BE FOCUSED IN THE NORTHWEST FORECAST AREA LATE
AFTERNOON WITH SHOWERS AND THUNDERSTORMS BECOMING WIDESPREAD THIS
EVENING ACROSS THE BULK OF THE CWA AS THE LOW LEVEL JET INTENSIFIES.
THIS SYSTEM SLOWLY TRUDGES EASTWARD OVERNIGHT WITH THE BEST CHANCES
FOR PRECIPITATION MAINLY ACROSS THE I29 CORRIDOR AND POINTS
EASTWARD.
PRECIPITABLE WATER VALUES REMAIN ABOVE NORMAL TODAY AND TONIGHT...SO
RAINFALL WILL LIKELY TO BE MODERATE TO HEAVY AT TIMES. FLASH
FLOODING WILL BE A CONCERN...BUT GIVEN THE HIGH FLASH FLOOD GUIDANCE
ON THE ORDER OF 2 TO 3 INCHES PER 3 HOURS IN THE CENTRAL AND EASTERN
FORECAST AREA WHERE THE HEAVIEST AMOUNTS ARE EXPECTED...WILL NOT
ISSUE ANY HEADLINES AT THIS POINT. BUT WILL NEED TO MONITOR THIS
POTENTIAL THIS EVENING AND TONIGHT. FORECAST SOUNDINGS SUGGEST THAT
SEVERE WEATHER THREAT WILL RATHER LOW THIS AFTERNOON AND
EVENING...BUT GIVEN THE STRONG DYNAMICS OF THE UPPER WAVE THERE IS A
SMALL THREAT FOR MARGINAL HAIL OR WINDS...MAINLY NEAR THE MO VALLEY.
BY LATE EVENING THIS THREAT DROPS SIGNIFICANTLY...AS WILL THE
POTENTIAL FOR MUCH THUNDER AT ALL. HIGHS TODAY WILL BE HAMPERED A
BIT BY THE CLOUDS AND RAIN TODAY...BUT WILL BE MILD IN THE MID 70S
TO LOWER 80S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 401 AM CDT THU AUG 27 2015
SIGNIFICANT WEATHER CONTINUES TO BE FRONT WEIGHTED AT THE START OF
THE LONGER RANGE. DEEPENING UPPER LEVEL WAVE SHOULD BE FAIRLY CLOSE
TO BEING CENTERED RIGHT OVER THE FSD CWA AT 12Z FRIDAY...BUT STILL
DEALING WITH A COUPLE DISTINCT COMMUNITIES OF SOLUTIONS...ONE A BIT
MORE NORTHWARD CONSISTING OF MOST OF THE DETERMINISTIC MODELS...AND
ONE MORE SOUTHWARD CONSISTING OF THE CANADIAN AND WRF-ARW/WRF NMM.
SOME HINTS IN THE WATER VAPOR EARLY THIS MORNING SUGGEST A BIT MORE
CREDENCE SHOULD BE GIVEN TO THIS SUBSET...WITH STRONGER OF THE WAVES
MOVING THROUGH SOUTHERN UTAH AND WHAT IMPACT THE CURRENT MCS WILL
HAVE ON BOUNDARY LOCATION. WHEREVER THE EXACT UPPER LOW SETS UP BY
EARLY FRIDAY...THE EASTERN CWA WILL REMAIN IN A PRECIPITATION
FAVORED DYNAMIC SET UP.
ONE THING THAT MAY BE A CHALLENGE IS GETTING A GREAT COVERAGE OF
THUNDER...WITH MOST PROFILES SIDING CLOSER TO MOIST NEUTRAL NEAR AND
BEHIND THE UPPER LOW. CONTINUE TO SHOW TRAJECTORY WRAPPING MID LEVEL
FRONTAL SUPPORT AND PRECIPITATION BEHIND SYSTEM...SO WILL CONTINUE
WITH A PERIOD OF CATEGORICAL PRECIPITATION DURING THE MORNING ACROSS
SOUTHWEST MINNESOTA...BUT ON A GRADUAL DECLINE FROM WEST TO EAST.
EVEN IF PRECIPITATION DOES END OVER MOST OF THE AREA BY EARLY TO MID
AFTERNOON...WILL CONTINUE TO HAVE FAIRLY WIDESPREAD CLOUDINESS
LINGER OVER MOST OF THE AREA TO IMPACT HEATING. WILL LIKELY HOLD
TEMPS IN THE UPPER 60S IN THE FAR EAST...AND SOME LATE DAY SUNSHINE
SHOULD PUSH TEMPS CLOSER TO 80 IN THE WEST.
CONCERN GOING INTO FRIDAY NIGHT WITH UPPER LOW CONTINUING TO SLOWLY
PULL EASTWARD IS JUST HOW MUCH PUSH THE STRATUS FIELD WILL GET
BEFORE FLOW WEAKENS WITH BUILDING RIDGE. MOST OF THE CWA TRAJECTORY
WOULD FAVOR DRYING...BUT THE FAR SOUTHEAST COULD SEE STRATUS LINGER
INTO MUCH OF THE NIGHT. EVEN NOT IMPOSSIBLE FOR THERE TO BE SOME
AREAS OF FOG WITHIN THE SURFACE RIDGE AXIS TOWARD THE I29 CORRIDOR.
FLOW WILL CONTINUE TO TREND TOWARD SOUTHERLY OVER THE REMAINDER OF
THE AREA AS WE MOVE THROUGH SATURDAY...AND THIS SOUTHERLY FLOW WILL
BE A FEATURE OF THE FORECAST FOR THE REMAINDER OF THE EXTENDED.
FEATURES...IN FACT...ARE FAIRLY STABLE THROUGH THE PERIOD WITH A
COUPLE OF WAVES PUSHING OVER A POSITIVELY TILTED RIDGE. POTENTIALLY
COULD GET A WEAK FRONTAL BOUNDARY TO LAY DOWN ACROSS THE AREA TOWARD
TUESDAY/WEDNESDAY...BUT FOR NOW WITH THE WARMISH TEMPS ALOFT AND
DISTINCT LACK OF CONVERGENCE ANYWHERE NEAR THE AREA...HAVE REMOVED
ATTEMPT BY BLENDED INITIALIZATION FOR SEVERAL PERIODS OF LOWER
PRECIPITATION CHANCES. OTHERWISE...TEMPS APPEAR TO HAVE A BIT OF A
COOL BIAS IN THE BLEND AND HAVE PUSHED MOST DAYTIME READINGS UP A
COUPLE DEGREES BY TUESDAY AND WEDNESDAY. TEMPTED TO DO MORE...BUT
INCREASED MOISTURE IN THE LOWER LEVELS AND WARMING TEMPS ALOFT
SHOULD KEEP SURFACE TEMPS BELOW MAXIMUM MIXING. READINGS IN THE WEST
WILL OCCASIONALLY PUSH INTO THE LOWER 90S...WHILE GENERALLY 80S
PREVAIL EACH DAY CENTRAL AND EAST. OVERNIGHT LOWS WILL MAINLY HOLD
IN THE LOWER TO MID 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 101 PM CDT THU AUG 27 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP ACROSS SOUTH
CENTRAL SOUTH DAKOTA INTO NORTHEAST NEBRASKA TONIGHT. SOME OF
THESE STORMS COULD INITIALL PRODUCE SOME HAIL AND WIND...BUT THE
BIGGER CONCERN IS THE POTENTIAL FOR HEAVY RAINFALL ACROSS EASTERN
SOUTH DAKOTA INTO NORTHWEST IOWA. THIS MAY IMPACT THE KFSD
TAF...WITH A GREATER IMPACT AT KSUX. LOWER CEILINGS WILL DEVELOP
BEHIND THE THUNDERSTORM COMPLEX...AND CONTINUE THROUGH FRIDAY
MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
603 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM CDT THU AUG 27 2015
AN MCS HAS DEVELOPED OVER WESTERN AND CENTRAL SOUTH DAKOTA AND WILL
HAS BEGUN MOVING INTO OUR WESTERN FORECAST AREA. THIS COMPLEX HAS A
HISTORY OF VERY STRONG WINDS WITH MIDLAND SD REPORTING 79 MPH GUSTS
AS IT MOVED OVERHEAD. GIVEN THAT THIS COMPLEX IS SHOWING SIGNS OF
WEAKENING AS IT MOVES EAST...THINK THAT THE SEVERE WIND THREAT WILL
BE GREATEST IN OUR SOUTH CENTRAL SD COUNTIES. HRRR SUGGESTS THAT IT
WILL SIGNIFICANTLY WEAKEN BY THE TIME IT HEADS EAST OF THE JAMES
RIVER.
THINK THIS THIS INITIAL WAVE OF SHOWERS AND THUNDERSTORMS WILL
APPROACH I29 SHORTLY AFTER SUNRISE AND WEAKEN FURTHER AS IT MOVES
THROUGH SW MN AND NW IA THROUGH MIDDAY. THERE WILL LIKELY BE SOME
SORT OF BREAK IN ACTIVITY BEHIND THIS COMPLEX...BUT THIS WILL BE
SHORT LIVED. SURFACE LOW PRESSURE SLIDING EASTWARD ALONG THE
MISSOURI RIVER AHEAD OF THE MAIN UPPER LOW DIGGING INTO CENTRAL
SD...WILL IGNITE FURTHER CONVECTION LATER THIS AFTERNOON AS WARM AIR
AND MOISTURE CONTINUES TO ADVECT INTO THE REGION. THIS INITIAL
ACTIVITY WILL LIKELY BE FOCUSED IN THE NORTHWEST FORECAST AREA LATE
AFTERNOON WITH SHOWERS AND THUNDERSTORMS BECOMING WIDESPREAD THIS
EVENING ACROSS THE BULK OF THE CWA AS THE LOW LEVEL JET INTENSIFIES.
THIS SYSTEM SLOWLY TRUDGES EASTWARD OVERNIGHT WITH THE BEST CHANCES
FOR PRECIPITATION MAINLY ACROSS THE I29 CORRIDOR AND POINTS
EASTWARD.
PRECIPITABLE WATER VALUES REMAIN ABOVE NORMAL TODAY AND TONIGHT...SO
RAINFALL WILL LIKELY TO BE MODERATE TO HEAVY AT TIMES. FLASH
FLOODING WILL BE A CONCERN...BUT GIVEN THE HIGH FLASH FLOOD GUIDANCE
ON THE ORDER OF 2 TO 3 INCHES PER 3 HOURS IN THE CENTRAL AND EASTERN
FORECAST AREA WHERE THE HEAVIEST AMOUNTS ARE EXPECTED...WILL NOT
ISSUE ANY HEADLINES AT THIS POINT. BUT WILL NEED TO MONITOR THIS
POTENTIAL THIS EVENING AND TONIGHT. FORECAST SOUNDINGS SUGGEST THAT
SEVERE WEATHER THREAT WILL RATHER LOW THIS AFTERNOON AND
EVENING...BUT GIVEN THE STRONG DYNAMICS OF THE UPPER WAVE THERE IS A
SMALL THREAT FOR MARGINAL HAIL OR WINDS...MAINLY NEAR THE MO VALLEY.
BY LATE EVENING THIS THREAT DROPS SIGNIFICANTLY...AS WILL THE
POTENTIAL FOR MUCH THUNDER AT ALL. HIGHS TODAY WILL BE HAMPERED A
BIT BY THE CLOUDS AND RAIN TODAY...BUT WILL BE MILD IN THE MID 70S
TO LOWER 80S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 401 AM CDT THU AUG 27 2015
SIGNIFICANT WEATHER CONTINUES TO BE FRONT WEIGHTED AT THE START OF
THE LONGER RANGE. DEEPENING UPPER LEVEL WAVE SHOULD BE FAIRLY CLOSE
TO BEING CENTERED RIGHT OVER THE FSD CWA AT 12Z FRIDAY...BUT STILL
DEALING WITH A COUPLE DISTINCT COMMUNITIES OF SOLUTIONS...ONE A BIT
MORE NORTHWARD CONSISTING OF MOST OF THE DETERMINISTIC MODELS...AND
ONE MORE SOUTHWARD CONSISTING OF THE CANADIAN AND WRF-ARW/WRF NMM.
SOME HINTS IN THE WATER VAPOR EARLY THIS MORNING SUGGEST A BIT MORE
CREDENCE SHOULD BE GIVEN TO THIS SUBSET...WITH STRONGER OF THE WAVES
MOVING THROUGH SOUTHERN UTAH AND WHAT IMPACT THE CURRENT MCS WILL
HAVE ON BOUNDARY LOCATION. WHEREVER THE EXACT UPPER LOW SETS UP BY
EARLY FRIDAY...THE EASTERN CWA WILL REMAIN IN A PRECIPITATION
FAVORED DYNAMIC SET UP.
ONE THING THAT MAY BE A CHALLENGE IS GETTING A GREAT COVERAGE OF
THUNDER...WITH MOST PROFILES SIDING CLOSER TO MOIST NEUTRAL NEAR AND
BEHIND THE UPPER LOW. CONTINUE TO SHOW TRAJECTORY WRAPPING MID LEVEL
FRONTAL SUPPORT AND PRECIPITATION BEHIND SYSTEM...SO WILL CONTINUE
WITH A PERIOD OF CATEGORICAL PRECIPITATION DURING THE MORNING ACROSS
SOUTHWEST MINNESOTA...BUT ON A GRADUAL DECLINE FROM WEST TO EAST.
EVEN IF PRECIPITATION DOES END OVER MOST OF THE AREA BY EARLY TO MID
AFTERNOON...WILL CONTINUE TO HAVE FAIRLY WIDESPREAD CLOUDINESS
LINGER OVER MOST OF THE AREA TO IMPACT HEATING. WILL LIKELY HOLD
TEMPS IN THE UPPER 60S IN THE FAR EAST...AND SOME LATE DAY SUNSHINE
SHOULD PUSH TEMPS CLOSER TO 80 IN THE WEST.
CONCERN GOING INTO FRIDAY NIGHT WITH UPPER LOW CONTINUING TO SLOWLY
PULL EASTWARD IS JUST HOW MUCH PUSH THE STRATUS FIELD WILL GET
BEFORE FLOW WEAKENS WITH BUILDING RIDGE. MOST OF THE CWA TRAJECTORY
WOULD FAVOR DRYING...BUT THE FAR SOUTHEAST COULD SEE STRATUS LINGER
INTO MUCH OF THE NIGHT. EVEN NOT IMPOSSIBLE FOR THERE TO BE SOME
AREAS OF FOG WITHIN THE SURFACE RIDGE AXIS TOWARD THE I29 CORRIDOR.
FLOW WILL CONTINUE TO TREND TOWARD SOUTHERLY OVER THE REMAINDER OF
THE AREA AS WE MOVE THROUGH SATURDAY...AND THIS SOUTHERLY FLOW WILL
BE A FEATURE OF THE FORECAST FOR THE REMAINDER OF THE EXTENDED.
FEATURES...IN FACT...ARE FAIRLY STABLE THROUGH THE PERIOD WITH A
COUPLE OF WAVES PUSHING OVER A POSITIVELY TILTED RIDGE. POTENTIALLY
COULD GET A WEAK FRONTAL BOUNDARY TO LAY DOWN ACROSS THE AREA TOWARD
TUESDAY/WEDNESDAY...BUT FOR NOW WITH THE WARMISH TEMPS ALOFT AND
DISTINCT LACK OF CONVERGENCE ANYWHERE NEAR THE AREA...HAVE REMOVED
ATTEMPT BY BLENDED INITIALIZATION FOR SEVERAL PERIODS OF LOWER
PRECIPITATION CHANCES. OTHERWISE...TEMPS APPEAR TO HAVE A BIT OF A
COOL BIAS IN THE BLEND AND HAVE PUSHED MOST DAYTIME READINGS UP A
COUPLE DEGREES BY TUESDAY AND WEDNESDAY. TEMPTED TO DO MORE...BUT
INCREASED MOISTURE IN THE LOWER LEVELS AND WARMING TEMPS ALOFT
SHOULD KEEP SURFACE TEMPS BELOW MAXIMUM MIXING. READINGS IN THE WEST
WILL OCCASIONALLY PUSH INTO THE LOWER 90S...WHILE GENERALLY 80S
PREVAIL EACH DAY CENTRAL AND EAST. OVERNIGHT LOWS WILL MAINLY HOLD
IN THE LOWER TO MID 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 557 AM CDT THU AUG 27 2015
COMPLEX OF SHOWERS AND THUNDERSTORMS MOVING SLOWLY EASTWARD ACROSS
SOUTHEAST SD AND NORTHEAST NEBRASKA WILL CONTINUE TO DISSIPATE AS
IT MOVES THROUGH AREAS EAST OF I29 THIS MORNING. SCATTERED SHOWERS
AND STORMS WILL REMAIN POSSIBLE TODAY BEHIND THIS BAND...BUT THE
BETTER CHANCES FOR PRECIPITATION ARRIVE AFTER 21Z IN THE NORTHWEST
AND EXPAND ELSEWHERE THIS EVENING. EXPECT MAINLY VFR CONDITIONS
TODAY WITH THE EXCEPTION OF SOME LOWER VISIBILITIES UNDER SHOWERS.
OTHERWISE...AS THE RAIN EXPANDS THIS EVENING AND
OVERNIGHT...MVFR/IFR CEILINGS AND VISIBILITY WILL BECOME MORE
LIKELY...PARTICULARLY AFTER MIDNIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
402 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM CDT THU AUG 27 2015
AN MCS HAS DEVELOPED OVER WESTERN AND CENTRAL SOUTH DAKOTA AND WILL
HAS BEGUN MOVING INTO OUR WESTERN FORECAST AREA. THIS COMPLEX HAS A
HISTORY OF VERY STRONG WINDS WITH MIDLAND SD REPORTING 79 MPH GUSTS
AS IT MOVED OVERHEAD. GIVEN THAT THIS COMPLEX IS SHOWING SIGNS OF
WEAKENING AS IT MOVES EAST...THINK THAT THE SEVERE WIND THREAT WILL
BE GREATEST IN OUR SOUTH CENTRAL SD COUNTIES. HRRR SUGGESTS THAT IT
WILL SIGNIFICANTLY WEAKEN BY THE TIME IT HEADS EAST OF THE JAMES
RIVER.
THINK THIS THIS INITIAL WAVE OF SHOWERS AND THUNDERSTORMS WILL
APPROACH I29 SHORTLY AFTER SUNRISE AND WEAKEN FURTHER AS IT MOVES
THROUGH SW MN AND NW IA THROUGH MIDDAY. THERE WILL LIKELY BE SOME
SORT OF BREAK IN ACTIVITY BEHIND THIS COMPLEX...BUT THIS WILL BE
SHORT LIVED. SURFACE LOW PRESSURE SLIDING EASTWARD ALONG THE
MISSOURI RIVER AHEAD OF THE MAIN UPPER LOW DIGGING INTO CENTRAL
SD...WILL IGNITE FURTHER CONVECTION LATER THIS AFTERNOON AS WARM AIR
AND MOISTURE CONTINUES TO ADVECT INTO THE REGION. THIS INITIAL
ACTIVITY WILL LIKELY BE FOCUSED IN THE NORTHWEST FORECAST AREA LATE
AFTERNOON WITH SHOWERS AND THUNDERSTORMS BECOMING WIDESPREAD THIS
EVENING ACROSS THE BULK OF THE CWA AS THE LOW LEVEL JET INTENSIFIES.
THIS SYSTEM SLOWLY TRUDGES EASTWARD OVERNIGHT WITH THE BEST CHANCES
FOR PRECIPITATION MAINLY ACROSS THE I29 CORRIDOR AND POINTS
EASTWARD.
PRECIPITABLE WATER VALUES REMAIN ABOVE NORMAL TODAY AND TONIGHT...SO
RAINFALL WILL LIKELY TO BE MODERATE TO HEAVY AT TIMES. FLASH
FLOODING WILL BE A CONCERN...BUT GIVEN THE HIGH FLASH FLOOD GUIDANCE
ON THE ORDER OF 2 TO 3 INCHES PER 3 HOURS IN THE CENTRAL AND EASTERN
FORECAST AREA WHERE THE HEAVIEST AMOUNTS ARE EXPECTED...WILL NOT
ISSUE ANY HEADLINES AT THIS POINT. BUT WILL NEED TO MONITOR THIS
POTENTIAL THIS EVENING AND TONIGHT. FORECAST SOUNDINGS SUGGEST THAT
SEVERE WEATHER THREAT WILL RATHER LOW THIS AFTERNOON AND
EVENING...BUT GIVEN THE STRONG DYNAMICS OF THE UPPER WAVE THERE IS A
SMALL THREAT FOR MARGINAL HAIL OR WINDS...MAINLY NEAR THE MO VALLEY.
BY LATE EVENING THIS THREAT DROPS SIGNIFICANTLY...AS WILL THE
POTENTIAL FOR MUCH THUNDER AT ALL. HIGHS TODAY WILL BE HAMPERED A
BIT BY THE CLOUDS AND RAIN TODAY...BUT WILL BE MILD IN THE MID 70S
TO LOWER 80S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 401 AM CDT THU AUG 27 2015
SIGNIFICANT WEATHER CONTINUES TO BE FRONT WEIGHTED AT THE START OF
THE LONGER RANGE. DEEPENING UPPER LEVEL WAVE SHOULD BE FAIRLY CLOSE
TO BEING CENTERED RIGHT OVER THE FSD CWA AT 12Z FRIDAY...BUT STILL
DEALING WITH A COUPLE DISTINCT COMMUNITIES OF SOLUTIONS...ONE A BIT
MORE NORTHWARD CONSISTING OF MOST OF THE DETERMINISTIC MODELS...AND
ONE MORE SOUTHWARD CONSISTING OF THE CANADIAN AND WRF-ARW/WRF NMM.
SOME HINTS IN THE WATER VAPOR EARLY THIS MORNING SUGGEST A BIT MORE
CREDENCE SHOULD BE GIVEN TO THIS SUBSET...WITH STRONGER OF THE WAVES
MOVING THROUGH SOUTHERN UTAH AND WHAT IMPACT THE CURRENT MCS WILL
HAVE ON BOUNDARY LOCATION. WHEREVER THE EXACT UPPER LOW SETS UP BY
EARLY FRIDAY...THE EASTERN CWA WILL REMAIN IN A PRECIPITATION
FAVORED DYNAMIC SET UP.
ONE THING THAT MAY BE A CHALLENGE IS GETTING A GREAT COVERAGE OF
THUNDER...WITH MOST PROFILES SIDING CLOSER TO MOIST NEUTRAL NEAR AND
BEHIND THE UPPER LOW. CONTINUE TO SHOW TRAJECTORY WRAPPING MID LEVEL
FRONTAL SUPPORT AND PRECIPITATION BEHIND SYSTEM...SO WILL CONTINUE
WITH A PERIOD OF CATEGORICAL PRECIPITATION DURING THE MORNING ACROSS
SOUTHWEST MINNESOTA...BUT ON A GRADUAL DECLINE FROM WEST TO EAST.
EVEN IF PRECIPITATION DOES END OVER MOST OF THE AREA BY EARLY TO MID
AFTERNOON...WILL CONTINUE TO HAVE FAIRLY WIDESPREAD CLOUDINESS
LINGER OVER MOST OF THE AREA TO IMPACT HEATING. WILL LIKELY HOLD
TEMPS IN THE UPPER 60S IN THE FAR EAST...AND SOME LATE DAY SUNSHINE
SHOULD PUSH TEMPS CLOSER TO 80 IN THE WEST.
CONCERN GOING INTO FRIDAY NIGHT WITH UPPER LOW CONTINUING TO SLOWLY
PULL EASTWARD IS JUST HOW MUCH PUSH THE STRATUS FIELD WILL GET
BEFORE FLOW WEAKENS WITH BUILDING RIDGE. MOST OF THE CWA TRAJECTORY
WOULD FAVOR DRYING...BUT THE FAR SOUTHEAST COULD SEE STRATUS LINGER
INTO MUCH OF THE NIGHT. EVEN NOT IMPOSSIBLE FOR THERE TO BE SOME
AREAS OF FOG WITHIN THE SURFACE RIDGE AXIS TOWARD THE I29 CORRIDOR.
FLOW WILL CONTINUE TO TREND TOWARD SOUTHERLY OVER THE REMAINDER OF
THE AREA AS WE MOVE THROUGH SATURDAY...AND THIS SOUTHERLY FLOW WILL
BE A FEATURE OF THE FORECAST FOR THE REMAINDER OF THE EXTENDED.
FEATURES...IN FACT...ARE FAIRLY STABLE THROUGH THE PERIOD WITH A
COUPLE OF WAVES PUSHING OVER A POSITIVELY TILTED RIDGE. POTENTIALLY
COULD GET A WEAK FRONTAL BOUNDARY TO LAY DOWN ACROSS THE AREA TOWARD
TUESDAY/WEDNESDAY...BUT FOR NOW WITH THE WARMISH TEMPS ALOFT AND
DISTINCT LACK OF CONVERGENCE ANYWHERE NEAR THE AREA...HAVE REMOVED
ATTEMPT BY BLENDED INITIALIZATION FOR SEVERAL PERIODS OF LOWER
PRECIPITATION CHANCES. OTHERWISE...TEMPS APPEAR TO HAVE A BIT OF A
COOL BIAS IN THE BLEND AND HAVE PUSHED MOST DAYTIME READINGS UP A
COUPLE DEGREES BY TUESDAY AND WEDNESDAY. TEMPTED TO DO MORE...BUT
INCREASED MOISTURE IN THE LOWER LEVELS AND WARMING TEMPS ALOFT
SHOULD KEEP SURFACE TEMPS BELOW MAXIMUM MIXING. READINGS IN THE WEST
WILL OCCASIONALLY PUSH INTO THE LOWER 90S...WHILE GENERALLY 80S
PREVAIL EACH DAY CENTRAL AND EAST. OVERNIGHT LOWS WILL MAINLY HOLD
IN THE LOWER TO MID 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 1102 PM CDT WED AUG 26 2015
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH MOST OF THE DAY
THURSDAY...WITH DETERIORATING CONDITIONS SPREADING OVER THE REGION
THURSDAY NIGHT. SHOULD SEE SOME ELEVATED SHOWERS/THUNDERSTORMS TO
OUR WEST THIS EVENING MOVE INTO AREAS MAINLY WEST OF I-29 OVERNIGHT
INTO EARLY THURSDAY. MODELS POINT AT CURRENT ACTIVITY WEAKENING AS
IT PROGRESSES EAST...BUT WILL MAINTAIN VICINITY MENTION FOR SHOWERS
AT KHON/KFSD TO INDICATE TIMING OF GREATER POTENTIAL.
BETTER THREAT OF RAINFALL WILL BEGIN TO AFFECT THE FORECAST AREA
LATE IN THE DAY THURSDAY...MORE LIKELY AFTER 28/00Z...AND WILL BEGIN
TO INTRODUCE MVFR CONDITIONS FOR THE LATTER PART OF THIS TAF PERIOD.
ENOUGH INSTABILITY THAT WE COULD SEE SOME THUNDERSTORMS WITH THE
LATE AFTERNOON ACTIVITY...THOUGH WITH TIMING UNCERTAINTIES WILL
LIMIT TO JUST SHOWERS FOR NOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...CHAPMAN
AVIATION...JH
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1244 AM CDT THU AUG 27 2015
.AVIATION...
VFR FLYING CONDITIONS PREVAIL OVERNIGHT THROUGH THURSDAY NIGHT.
HOWEVER...THERE MAY BE SOME STRATUS AT THE MVFR LEVEL ALONG THE
ESCARPMENT BETWEEN 08Z AND 16Z. THERE IS A SMALL POSSIBILITY OF
BRIEF CIGS AT KSAT/KSSF...ALTHOUGH WILL KEEP SCT FOR NOW. S TO SE
WINDS OF 10 KTS OR LESS PREVAIL.
&&
.PREV DISCUSSION... /ISSUED 642 PM CDT WED AUG 26 2015/
AVIATION...
THERE ARE ISOLATED SHOWERS AND THUNDERSTORMS NORTH OF DRT MOVING
TOWARD THE SOUTHWEST. THERE IS A SLIGHT CHANCE THAT ONE OF THESE
COULD MOVE OVER THE AIRPORT AND REDUCE VIS TO MVFR...BUT THE
PROBABILITY IS VERY LOW. ANY CHANCE FOR CONVECTION WILL END BY
AROUND 03Z. OTHERWISE CONDITIONS WILL BE VFR AT TERMINALS THROUGH
THE PERIOD. WE COULD SEE SOME LOW CLOUDS FORM IN THE SOUTHEASTERLY
FLOW THURSDAY MORNING...BUT NOT EXPECTING ANY CIGS. WINDS WILL
GENERALLY BE LESS THAN 10 KTS.
PREV DISCUSSION... /ISSUED 254 PM CDT WED AUG 26 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
ISOLATED SHOWERS HAVE DEVELOPED OVER THE HILL COUNTRY AND EDWARDS
PLATEAU. THE LATEST TEXAS TECH WRF AND HRRR RUNS INDICATE THIS
ACTIVITY WILL REMAIN ISOLATED AND BARELY BRING MEASURABLE RAIN TO
ONLY A FEW SPOTS. WE HAVE REMOVED THE CHANCE FOR DOWNDRAFT WINDS
IN THE HAZARDOUS WEATHER OUTLOOK. OTHERWISE...WE EXPECT THE
SHOWERS TO QUICKLY DIE BY SUNSET. DRY AIR CONTINUES TO FILTER INTO
THE REGION...AND WHEN COUPLED WITH SUBSIDENCE BELOW THE UPPER
LEVEL RIDGE...WE EXPECT MOSTLY CLEAR SKIES OVERNIGHT...WITH THE
EXCEPTION OF SOME LOW CLOUDS ALONG THE BALCONES ESCARPMENT.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
THE UPPER LEVEL RIDGE SLIDES A BIT WEST OVER THE NEXT FEW
DAYS...WITH A RESULTING DROP IN HIGH AND LOW TEMPERATURES. EARLY
MORNINGS WILL BE PLEASANT FOR THE TIME OF YEAR...BUT AFTERNOONS
STILL WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. A CUTOFF
LOW/TROUGH EVENTUALLY CARVES OUT OVER NORTHEAST TEXAS EARLY NEXT
WEEK...AND COMBINES WITH THE REMNANTS OF ERIKA TO PRODUCE A
LONGWAVE TROUGH OVER THE EASTERN U.S.. GULF MOISTURE WILL COINCIDE
WITH THE TROUGH DEVELOPMENT...AND HENCE BRING A CHANCE OF RAIN BY
THE MIDDLE OF NEXT WEEK. HOWEVER...THE WESTERN EDGE OF THE TROUGH
WILL HAVE A SHARP GRADIENT OF COVERAGE...SO AT THIS TIME WE WILL
KEEP POPS LOW. LOWER HEIGHTS AND CLOUD COVER SHOULD DROP TEMPS TO
NEAR NORMAL...LOWER 90S FOR HIGHS AT MANY LOCATIONS...AND LOWS
AROUND 70...BY THE END OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 73 98 73 97 74 / 0 0 0 0 -
AUSTIN BERGSTROM INTL AIRPORT 68 97 69 96 70 / 0 0 0 0 -
NEW BRAUNFELS MUNI AIRPORT 70 97 70 96 72 / 0 0 0 0 -
BURNET MUNI AIRPORT 71 97 71 96 72 / 0 0 0 0 -
DEL RIO INTL AIRPORT 73 100 72 99 73 / 0 0 0 0 -
GEORGETOWN MUNI AIRPORT 71 98 72 96 74 / 0 0 0 0 -
HONDO MUNI AIRPORT 69 98 68 97 70 / 0 0 0 0 -
SAN MARCOS MUNI AIRPORT 70 97 71 96 72 / 0 0 0 0 -
LA GRANGE - FAYETTE REGIONAL 70 97 71 95 72 / 0 0 0 0 -
SAN ANTONIO INTL AIRPORT 72 97 72 96 73 / 0 0 0 0 -
STINSON MUNI AIRPORT 72 98 71 97 72 / 0 0 0 0 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1210 PM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT THU AUG 27 2015
AT 3 AM...A MESOSCALE CONVECTIVE COMPLEX WAS MOVING EAST ACROSS
SOUTH DAKOTA. THIS SYSTEM WAS NOT HANDLED WELL BY THE
DETERMINISTIC NAM...GFS...AND ECMWF. MEANWHILE BOTH THE ARW AND
NMM BRING THIS SYSTEM INTO SOUTHEAST MINNESOTA THIS AFTERNOON.
THIS SEEMS A BIT TOO MUCH OVER DONE CONSIDERING THE DRY DEW POINTS
OVER THE AREA. THE HRRR ALSO MOVES THIS SYSTEM EAST AND WEAKENS IT
ACROSS MINNESOTA. HOWEVER SOME LINGERING SHOWERS AND STORMS
CONTINUE ALONG A BAND OF 700 TO 500 MB FRONTOGENESIS. WITH SO MUCH
UNCERTAINTY...OPTED TO GO MORE OF A BLEND THAT SOME OF THE SHOWERS
AND STORMS WOULD MOVE INTO THE FAR WESTERN COUNTIES OF THE COUNTY
WARNING AREA THIS AFTERNOON. HOWEVER DID NOT INCLUDE ANY
PRECIPITATION INTO CLARK AND TAYLOR COUNTIES AT THIS TIME.
FOR TONIGHT...THE NAM...GFS...AND ECMWF TRACK THE SURFACE LOW
NEAR THE MINNESOTA AND IOWA BORDER. WITH MUCH OF THE 950 TO
500 MB FRONTOGENESIS REMAINING ACROSS SOUTHERN MINNESOTA AND
NORTHERN IOWA OVERNIGHT KEPT THE HIGHEST RAIN CHANCES MAINLY WEST
OF THE MISSISSIPPI RIVER. WILL HAVE TO WATCH HOW CYCLOGENESIS
TAKES PLACE ACROSS NEBRASKA TODAY. THERE IS SOME SUGGESTION IN THE
MESO MODELS THAT THE STRONGER WAVE COMING OUT OF THE CENTRAL AND
NORTHERN PLAINS WILL BE LOCATED MUCH FURTHER SOUTH AS THE SHORT
WAVE EJECTS NORTHEAST OUT OF UTAH THIS MORNING. IF THIS SCENARIO
COMES TRUE...WE MAY BE TOO FAR NORTH WITH THE RAINFALL TONIGHT AND
FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 346 AM CDT THU AUG 27 2015
FROM FRIDAY INTO FRIDAY NIGHT...THE 27.00Z DETERMINISTIC
GFS...NAM...AND ECMWF CONTINUE TO SHOW STRONG 950 TO 500 MB
FRONTOGENESIS AND 925 TO 850 MB MOISTURE TRANSPORT ALONG AND
NORTH OF THE INTERSTATE 90 CORRIDOR. THIS OCCURS AS A SHORT WAVE
TROUGH LIFTS EAST NORTHEAST OUT OF NEBRASKA. DESPITE THE LACK OF A
INSTABILITY...PRECIPITABLE WATER VALUES RANGE AROUND 1.6 INCHES
AND WARM CLOUD LAYER DEPTHS RANGING BETWEEN 4 AND 4.5 KM...THERE
WILL BE COALESCENCE OF THE RAIN DROPLETS...THUS...HEAVY RAIN LOOKS
POSSIBLE. BOTH THE NAM AND GFS SUGGEST A BAND OF 3 TO 4 INCHES.
MEANWHILE THE ECMWF LOOKS MORE REASONABLE CONSIDERING THE
INSTABILITY WITH A 1 TO 3 INCH BAND.
WHILE THERE IS GREAT AGREEMENT AMONGST THESE MODELS...THERE IS
SOME CONCERN THAT THE SHORT WAVE CURRENTLY DEVELOPING ACROSS
SOUTHEAST UTAH MAY CAUSE THE SURFACE LOW TO TAKE A MUCH FURTHER
SOUTH TRACK ACROSS IOWA. THE ARW...NMM...GEM...AND 11 OF THE 12
GFS MEMBERS WOULD SUGGEST THAT THIS COULD BE A POSSIBILITY. IF
THIS SCENARIO DID COME TRUE...THAN THE RAIN BAND WOULD HAVE TO BE
SHIFTED MUCH FURTHER SOUTH WHICH WOULD BE GREAT FOR THE ABNORMALLY
DRY AND MODERATE DROUGHT AREAS OF SOUTHWEST WISCONSIN AND
NORTHEAST IOWA.
FOR THE TIME BEING...STAY WITH THE MORE CONSISTENT GFS...NAM...
AND ECMWF AND WILL WATCH TO SEE HOW THE CYCLOGENESIS DEVELOPS
ACROSS THE CENTRAL PLAINS TODAY.
FROM TUESDAY THROUGH WEDNESDAY...THE MODELS CONTINUE TO SHOW THAT
A STRONG RIDGE OF HIGH PRESSURE WILL BE LOCATED ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. WITH 925 MB TEMPERATURES RUNNING AROUND
26 TO 27C...HIGH TEMPERATURES IN THE RIVER VALLEYS WILL LIKELY
CLIMB INTO THE LOWER 90S...AND INTO THE MID TO UPPER 80S. SINCE
THIS HAS BEEN A VERY CONSISTENT SIGNAL...RAISED THE MODEL
CONSENSUS HIGH TEMPERATURES ON BOTH DAYS BY 3 TO 5 DEGREES IN THE
RIVER VALLEYS AND 2 DEGREES ELSEWHERE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1209 PM CDT THU AUG 27 2015
AN AREA OF SURFACE LOW PRESSURE CONTINUES TO DEVELOP OVER
SOUTHWEST NEBRASKA THIS MORNING. THE 27.12Z GUIDANCE HAS REMAINED
CONSISTENT WITH PREVIOUS SOLUTIONS OF MOVING THIS SURFACE LOW
NORTHEAST AND INTO NORTHWEST IOWA BY EARLY FRIDAY AFTERNOON. THIS
WILL OCCUR AS A SHORT WAVE TROUGH COMING ACROSS WYOMING MERGES
WITH ANOTHER SHORT WAVE TROUGH COMING OUT OF COLORADO TO FORM A
UNIFIED SYSTEM TO MOVE ACROSS THE REGION FRIDAY. THE FORCING AHEAD
OF THIS SYSTEM WILL START TO INCREASE LATE TONIGHT INTO FRIDAY
MORNING. A BAND OF LOW LEVEL FRONTOGENESIS WILL START TO TAKE
SHAPE ALONG THE IOWA/MINNESOTA BORDER NORTH OF THE EXPECTED
POSITION OF THE SURFACE WARM FRONT. THE ISENTROPIC UP GLIDE ON THE
300K SURFACE WILL INCREASE TO AROUND 4 UBAR/S ALONG AND SOUTH OF
THE WARM FRONT...BUT THE BEST FORCING WILL REMAIN TO THE WEST OF
THE AREA THROUGH 18Z FRIDAY AND SHOULD SPREAD IN FRIDAY AFTERNOON.
THE TIMING OF THE RAIN LOOKS TO BE A BIT SLOWER ON THE 27.12Z NAM
AND 27.15Z HRRR-CR...SO WILL SHOW A VCSH FOR SOME SPRINKLES OUT OF
A HIGH VFR DECK COMING IN LATE TONIGHT WITH PREDOMINANT SHOWERS
FOR KRST AROUND 28.11Z AND 28.14Z FOR KLSE. CONDITIONS SHOULD
INITIALLY BE VFR BUT GO DOWN TO MVFR AS THE HEAVIER RAINS START TO
MOVE TO SATURATE THE LOWER BOUNDARY LAYER. EXPECTING IFR
CONDITIONS TO DEVELOP BUT NOT UNTIL AFTER 18Z FRIDAY. THE
INSTABILITY WITH THIS SYSTEM LOOKS VERY LIMITED...BUT WITH THE
STRENGTH OF THE FORCING THERE PROBABLY WILL BE SOME EMBEDDED
STORMS WITH THE SHOWERS. HOWEVER...THE CONFIDENCE ON WHERE AND
WHEN THESE MAY OCCUR TO TOO LOW TO INCLUDE IN EITHER TAF AT THIS
TIME.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY NIGHT
ISSUED AT 346 AM CDT THU AUG 27 2015
BOTH THE GFS AND NAM ARE SUGGESTING 3 TO 4 INCHES RAIN ALONG AND
NORTH OF THE INTERSTATE 90 CORRIDOR. MEANWHILE THE THE ECMWF HAS
1 TO 3 INCHES OF RAIN IN THIS SAME GENERAL LOCATION. CONSIDERING
THE AMOUNT OF INSTABILITY LOCATED AROUND THE AREA...THOUGHT THAT
THE ECMWF AMOUNTS SEEMED A BIT MORE REALISTIC...SO TRENDED THE
QPFS TOWARD IT. ELSEWHERE RAINFALL AMOUNTS LOOK TO BE LESS THAN
AN INCH.
HOWEVER AS STATED IN THE LONG TERM SECTION WILL HAVE TO
WATCH HOW THIS HEAVY RAINFALL BAND DEVELOPS TONIGHT...BECAUSE 11
OF 12 OF GFS FAMILY MEMBERS...GEM...ARW...AND NMM HAVE THE
HEAVIEST QPF BAND SOUTH OF THE INTERSTATE 90 CORRIDOR WHICH WOULD
BE GREAT FOR THE ABNORMALLY DRY AND DROUGHT AREAS OF NORTHEAST
IOWA AND SOUTHWEST WISCONSIN.
WITH HOURLY RAIN RATES LESS THAN AN INCH AN HOUR...NOT ANTICIPATING
ANY ISSUES WITH URBANIZED FLOODING. IN ADDITION...AREA RIVERS AND
STREAMS HAVE FLOWS CURRENTLY RUNNING ANYWHERE FROM 25 TO 50 PERCENT
OF CLIMATOLOGY. AS A RESULT...THIS RAIN SHOULD ONLY RESULT IN BANK
RISES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
641 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT THU AUG 27 2015
AT 3 AM...A MESOSCALE CONVECTIVE COMPLEX WAS MOVING EAST ACROSS
SOUTH DAKOTA. THIS SYSTEM WAS NOT HANDLED WELL BY THE
DETERMINISTIC NAM...GFS...AND ECMWF. MEANWHILE BOTH THE ARW AND
NMM BRING THIS SYSTEM INTO SOUTHEAST MINNESOTA THIS AFTERNOON.
THIS SEEMS A BIT TOO MUCH OVER DONE CONSIDERING THE DRY DEW POINTS
OVER THE AREA. THE HRRR ALSO MOVES THIS SYSTEM EAST AND WEAKENS IT
ACROSS MINNESOTA. HOWEVER SOME LINGERING SHOWERS AND STORMS
CONTINUE ALONG A BAND OF 700 TO 500 MB FRONTOGENESIS. WITH SO MUCH
UNCERTAINTY...OPTED TO GO MORE OF A BLEND THAT SOME OF THE SHOWERS
AND STORMS WOULD MOVE INTO THE FAR WESTERN COUNTIES OF THE COUNTY
WARNING AREA THIS AFTERNOON. HOWEVER DID NOT INCLUDE ANY
PRECIPITATION INTO CLARK AND TAYLOR COUNTIES AT THIS TIME.
FOR TONIGHT...THE NAM...GFS...AND ECMWF TRACK THE SURFACE LOW
NEAR THE MINNESOTA AND IOWA BORDER. WITH MUCH OF THE 950 TO
500 MB FRONTOGENESIS REMAINING ACROSS SOUTHERN MINNESOTA AND
NORTHERN IOWA OVERNIGHT KEPT THE HIGHEST RAIN CHANCES MAINLY WEST
OF THE MISSISSIPPI RIVER. WILL HAVE TO WATCH HOW CYCLOGENESIS
TAKES PLACE ACROSS NEBRASKA TODAY. THERE IS SOME SUGGESTION IN THE
MESO MODELS THAT THE STRONGER WAVE COMING OUT OF THE CENTRAL AND
NORTHERN PLAINS WILL BE LOCATED MUCH FURTHER SOUTH AS THE SHORT
WAVE EJECTS NORTHEAST OUT OF UTAH THIS MORNING. IF THIS SCENARIO
COMES TRUE...WE MAY BE TOO FAR NORTH WITH THE RAINFALL TONIGHT AND
FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 346 AM CDT THU AUG 27 2015
FROM FRIDAY INTO FRIDAY NIGHT...THE 27.00Z DETERMINISTIC
GFS...NAM...AND ECMWF CONTINUE TO SHOW STRONG 950 TO 500 MB
FRONTOGENESIS AND 925 TO 850 MB MOISTURE TRANSPORT ALONG AND
NORTH OF THE INTERSTATE 90 CORRIDOR. THIS OCCURS AS A SHORT WAVE
TROUGH LIFTS EAST NORTHEAST OUT OF NEBRASKA. DESPITE THE LACK OF A
INSTABILITY...PRECIPITABLE WATER VALUES RANGE AROUND 1.6 INCHES
AND WARM CLOUD LAYER DEPTHS RANGING BETWEEN 4 AND 4.5 KM...THERE
WILL BE COALESCENCE OF THE RAIN DROPLETS...THUS...HEAVY RAIN LOOKS
POSSIBLE. BOTH THE NAM AND GFS SUGGEST A BAND OF 3 TO 4 INCHES.
MEANWHILE THE ECMWF LOOKS MORE REASONABLE CONSIDERING THE
INSTABILITY WITH A 1 TO 3 INCH BAND.
WHILE THERE IS GREAT AGREEMENT AMONGST THESE MODELS...THERE IS
SOME CONCERN THAT THE SHORT WAVE CURRENTLY DEVELOPING ACROSS
SOUTHEAST UTAH MAY CAUSE THE SURFACE LOW TO TAKE A MUCH FURTHER
SOUTH TRACK ACROSS IOWA. THE ARW...NMM...GEM...AND 11 OF THE 12
GFS MEMBERS WOULD SUGGEST THAT THIS COULD BE A POSSIBILITY. IF
THIS SCENARIO DID COME TRUE...THAN THE RAIN BAND WOULD HAVE TO BE
SHIFTED MUCH FURTHER SOUTH WHICH WOULD BE GREAT FOR THE ABNORMALLY
DRY AND MODERATE DROUGHT AREAS OF SOUTHWEST WISCONSIN AND
NORTHEAST IOWA.
FOR THE TIME BEING...STAY WITH THE MORE CONSISTENT GFS...NAM...
AND ECMWF AND WILL WATCH TO SEE HOW THE CYCLOGENESIS DEVELOPS
ACROSS THE CENTRAL PLAINS TODAY.
FROM TUESDAY THROUGH WEDNESDAY...THE MODELS CONTINUE TO SHOW THAT
A STRONG RIDGE OF HIGH PRESSURE WILL BE LOCATED ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. WITH 925 MB TEMPERATURES RUNNING AROUND
26 TO 27C...HIGH TEMPERATURES IN THE RIVER VALLEYS WILL LIKELY
CLIMB INTO THE LOWER 90S...AND INTO THE MID TO UPPER 80S. SINCE
THIS HAS BEEN A VERY CONSISTENT SIGNAL...RAISED THE MODEL
CONSENSUS HIGH TEMPERATURES ON BOTH DAYS BY 3 TO 5 DEGREES IN THE
RIVER VALLEYS AND 2 DEGREES ELSEWHERE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 640 AM CDT THU AUG 27 2015
MORNING FOG WILL DISSIPATE AROUND THE KLSE AIRFIELD IN THE NEXT
HOUR OR SO. THEN VFR CONDITIONS ARE EXPECTED AS A WEATHER SYSTEM
MOVES TOWARD THE AIRFIELDS FOR FRIDAY. EXPECT CIGS/VSBYS TO BE
LOWERED TO AT LEAST MVFR FRIDAY...BUT TRENDS WILL LIKELY BE TOWARD
IFR IN SHRA/RA.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY NIGHT
ISSUED AT 346 AM CDT THU AUG 27 2015
BOTH THE GFS AND NAM ARE SUGGESTING 3 TO 4 INCHES RAIN ALONG AND
NORTH OF THE INTERSTATE 90 CORRIDOR. MEANWHILE THE THE ECMWF HAS
1 TO 3 INCHES OF RAIN IN THIS SAME GENERAL LOCATION. CONSIDERING
THE AMOUNT OF INSTABILITY LOCATED AROUND THE AREA...THOUGHT THAT
THE ECMWF AMOUNTS SEEMED A BIT MORE REALISTIC...SO TRENDED THE
QPFS TOWARD IT. ELSEWHERE RAINFALL AMOUNTS LOOK TO BE LESS THAN
AN INCH.
HOWEVER AS STATED IN THE LONG TERM SECTION WILL HAVE TO
WATCH HOW THIS HEAVY RAINFALL BAND DEVELOPS TONIGHT...BECAUSE 11
OF 12 OF GFS FAMILY MEMBERS...GEM...ARW...AND NMM HAVE THE
HEAVIEST QPF BAND SOUTH OF THE INTERSTATE 90 CORRIDOR WHICH WOULD
BE GREAT FOR THE ABNORMALLY DRY AND DROUGHT AREAS OF NORTHEAST
IOWA AND SOUTHWEST WISCONSIN.
WITH HOURLY RAIN RATES LESS THAN AN INCH AN HOUR...NOT ANTICIPATING
ANY ISSUES WITH URBANIZED FLOODING. IN ADDITION...AREA RIVERS AND
STREAMS HAVE FLOWS CURRENTLY RUNNING ANYWHERE FROM 25 TO 50 PERCENT
OF CLIMATOLOGY. AS A RESULT...THIS RAIN SHOULD ONLY RESULT IN BANK
RISES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BAUMGARDT
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
347 AM CDT THU AUG 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT THU AUG 27 2015
AT 3 AM...A MESOSCALE CONVECTIVE COMPLEX WAS MOVING EAST ACROSS
SOUTH DAKOTA. THIS SYSTEM WAS NOT HANDLED WELL BY THE
DETERMINISTIC NAM...GFS...AND ECMWF. MEANWHILE BOTH THE ARW AND
NMM BRING THIS SYSTEM INTO SOUTHEAST MINNESOTA THIS AFTERNOON.
THIS SEEMS A BIT TOO MUCH OVER DONE CONSIDERING THE DRY DEW POINTS
OVER THE AREA. THE HRRR ALSO MOVES THIS SYSTEM EAST AND WEAKENS IT
ACROSS MINNESOTA. HOWEVER SOME LINGERING SHOWERS AND STORMS
CONTINUE ALONG A BAND OF 700 TO 500 MB FRONTOGENESIS. WITH SO MUCH
UNCERTAINTY...OPTED TO GO MORE OF A BLEND THAT SOME OF THE SHOWERS
AND STORMS WOULD MOVE INTO THE FAR WESTERN COUNTIES OF THE COUNTY
WARNING AREA THIS AFTERNOON. HOWEVER DID NOT INCLUDE ANY
PRECIPITATION INTO CLARK AND TAYLOR COUNTIES AT THIS TIME.
FOR TONIGHT...THE NAM...GFS...AND ECMWF TRACK THE SURFACE LOW
NEAR THE MINNESOTA AND IOWA BORDER. WITH MUCH OF THE 950 TO
500 MB FRONTOGENESIS REMAINING ACROSS SOUTHERN MINNESOTA AND
NORTHERN IOWA OVERNIGHT KEPT THE HIGHEST RAIN CHANCES MAINLY WEST
OF THE MISSISSIPPI RIVER. WILL HAVE TO WATCH HOW CYCLOGENESIS
TAKES PLACE ACROSS NEBRASKA TODAY. THERE IS SOME SUGGESTION IN THE
MESO MODELS THAT THE STRONGER WAVE COMING OUT OF THE CENTRAL AND
NORTHERN PLAINS WILL BE LOCATED MUCH FURTHER SOUTH AS THE SHORT
WAVE EJECTS NORTHEAST OUT OF UTAH THIS MORNING. IF THIS SCENARIO
COMES TRUE...WE MAY BE TOO FAR NORTH WITH THE RAINFALL TONIGHT AND
FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 346 AM CDT THU AUG 27 2015
FROM FRIDAY INTO FRIDAY NIGHT...THE 27.00Z DETERMINISTIC
GFS...NAM...AND ECMWF CONTINUE TO SHOW STRONG 950 TO 500 MB
FRONTOGENESIS AND 925 TO 850 MB MOISTURE TRANSPORT ALONG AND
NORTH OF THE INTERSTATE 90 CORRIDOR. THIS OCCURS AS A SHORT WAVE
TROUGH LIFTS EAST NORTHEAST OUT OF NEBRASKA. DESPITE THE LACK OF A
INSTABILITY...PRECIPITABLE WATER VALUES RANGE AROUND 1.6 INCHES
AND WARM CLOUD LAYER DEPTHS RANGING BETWEEN 4 AND 4.5 KM...THERE
WILL BE COALESCENCE OF THE RAIN DROPLETS...THUS...HEAVY RAIN LOOKS
POSSIBLE. BOTH THE NAM AND GFS SUGGEST A BAND OF 3 TO 4 INCHES.
MEANWHILE THE ECMWF LOOKS MORE REASONABLE CONSIDERING THE
INSTABILITY WITH A 1 TO 3 INCH BAND.
WHILE THERE IS GREAT AGREEMENT AMONGST THESE MODELS...THERE IS
SOME CONCERN THAT THE SHORT WAVE CURRENTLY DEVELOPING ACROSS
SOUTHEAST UTAH MAY CAUSE THE SURFACE LOW TO TAKE A MUCH FURTHER
SOUTH TRACK ACROSS IOWA. THE ARW...NMM...GEM...AND 11 OF THE 12
GFS MEMBERS WOULD SUGGEST THAT THIS COULD BE A POSSIBILITY. IF
THIS SCENARIO DID COME TRUE...THAN THE RAIN BAND WOULD HAVE TO BE
SHIFTED MUCH FURTHER SOUTH WHICH WOULD BE GREAT FOR THE ABNORMALLY
DRY AND MODERATE DROUGHT AREAS OF SOUTHWEST WISCONSIN AND
NORTHEAST IOWA.
FOR THE TIME BEING...STAY WITH THE MORE CONSISTENT GFS...NAM...
AND ECMWF AND WILL WATCH TO SEE HOW THE CYCLOGENESIS DEVELOPS
ACROSS THE CENTRAL PLAINS TODAY.
FROM TUESDAY THROUGH WEDNESDAY...THE MODELS CONTINUE TO SHOW THAT
A STRONG RIDGE OF HIGH PRESSURE WILL BE LOCATED ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. WITH 925 MB TEMPERATURES RUNNING AROUND
26 TO 27C...HIGH TEMPERATURES IN THE RIVER VALLEYS WILL LIKELY
CLIMB INTO THE LOWER 90S...AND INTO THE MID TO UPPER 80S. SINCE
THIS HAS BEEN A VERY CONSISTENT SIGNAL...RAISED THE MODEL
CONSENSUS HIGH TEMPERATURES ON BOTH DAYS BY 3 TO 5 DEGREES IN THE
RIVER VALLEYS AND 2 DEGREES ELSEWHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1130 PM CDT WED AUG 26 2015
SCENARIO SCREAMS WIDESPREAD VALLEY FOG FOR KLSE...WITH HIGH PRESSURE
OVERHEAD...DEEP LIGHT WIND LAYER...AND T/TD SPREAD AT 03Z NOW ONLY 5
DEGREES. A 1-3 HOUR PERIOD OF 1/4SM SEEMED LIKELY...AND WOULD HAVE
ALREADY UPDATED TAF TO REFLECT CONFIDENCE. HOWEVER...A BATCH OF MID
LEVEL CLOUDS HAVE MOVED INTO CENTRAL MN...AND LOOK TO TAKE A
EAST/SOUTHEAST TRACK OVERNIGHT. THE RAP/HRRR/NAM ALL SUGGEST THIS
BKN 6-8 KFT DECK WOULD MOVE OVER KLSE BEFORE 12Z...AND COULD PUT THE
BREAKS ON THE DENSE FOG DEVELOPMENT. WILL IT THIN BEFORE IT MAKES
IT? WILL IT GET IN TOO LATE TO INHIBIT FOG FORMATION? ELECTING TO
KEEP FORECAST AS IS. EXPECT UPDATES BASED ON CLOUD TRENDS OVERNIGHT.
FOR KRST...NOT SOLD ON THE MVFR BR ANYMORE WITH A FEW CLOUDS MORE
LIKELY AT KRST.
FOR THE REST OF THU...CLOUDS WILL BE ON THE INCREASE FROM THE
WEST...WITH LOWER CIGS OVERNIGHT. EXPECT RAIN TO MOVE IN
OVERNIGHT...AND LIKELY HANG AROUND FOR THE BETTER PART OF FRIDAY.
LOOK FOR MVFR/IFR CIGS-VSBYS.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY NIGHT
ISSUED AT 346 AM CDT THU AUG 27 2015
BOTH THE GFS AND NAM ARE SUGGESTING 3 TO 4 INCHES RAIN ALONG AND
NORTH OF THE INTERSTATE 90 CORRIDOR. MEANWHILE THE THE ECMWF HAS
1 TO 3 INCHES OF RAIN IN THIS SAME GENERAL LOCATION. CONSIDERING
THE AMOUNT OF INSTABILITY LOCATED AROUND THE AREA...THOUGHT THAT
THE ECMWF AMOUNTS SEEMED A BIT MORE REALISTIC...SO TRENDED THE
QPFS TOWARD IT. ELSEWHERE RAINFALL AMOUNTS LOOK TO BE LESS THAN
AN INCH.
HOWEVER AS STATED IN THE LONG TERM SECTION WILL HAVE TO
WATCH HOW THIS HEAVY RAINFALL BAND DEVELOPS TONIGHT...BECAUSE 11
OF 12 OF GFS FAMILY MEMBERS...GEM...ARW...AND NMM HAVE THE
HEAVIEST QPF BAND SOUTH OF THE INTERSTATE 90 CORRIDOR WHICH WOULD
BE GREAT FOR THE ABNORMALLY DRY AND DROUGHT AREAS OF NORTHEAST
IOWA AND SOUTHWEST WISCONSIN.
WITH HOURLY RAIN RATES LESS THAN AN INCH AN HOUR...NOT ANTICIPATING
ANY ISSUES WITH URBANIZED FLOODING. IN ADDITION...AREA RIVERS AND
STREAMS HAVE FLOWS CURRENTLY RUNNING ANYWHERE FROM 25 TO 50 PERCENT
OF CLIMATOLOGY. AS A RESULT...THIS RAIN SHOULD ONLY RESULT IN BANK
RISES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RIECK
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
955 PM MST FRI AUG 28 2015
.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT WILL KEEP HIGH TEMPERATURES WELL ABOVE
SEASONAL NORMALS THROUGH SATURDAY WITH HOTTER LOWER DESERTS REACHING
OR EXCEEDING 110. THERE WILL BE SUFFICIENT MOISTURE EAST OF THE LOWER
COLORADO RIVER TO SUPPORT ISOLATED TO SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS THROUGH SUNDAY. STARTING MONDAY DRIER WESTERLY FLOW
ALOFT WILL PUSH THE MOISTURE OFF TO THE EAST LIMITING STORM CHANCES
PRIMARILY TO HIGHER TERRAIN AREAS TO THE EAST OF PHOENIX. THERE WILL
BE A GRADUAL COOLING TREND STARTING SUNDAY WITH CENTRAL DESERTS HIGH
TEMPERATURES DROPPING TO AROUND SEASONAL NORMALS BY THE MIDDLE OF
NEXT WEEK.
&&
.DISCUSSION...
STORM ACTIVITY HAS DISSIPATED THIS EVENING ACROSS ARIZONA AND
SOUTHEAST CALIFORNIA. ANTICIPATE THAT TO REMAIN THE CASE OVERNIGHT AS
LOWER LEVELS HAVE HAD SOME DRYING OVER A GOOD PORTION OF
ARIZONA PER 00Z SOUNDINGS...LESS SO OVER SOUTHWEST ARIZONA AND INTO
FAR SOUTHEAST CALIFORNIA. ALSO...SONORA IS FAIRLY QUIET AND NEAREST
LARGE ACTIVITY IS OVER EASTERN NEW MEXICO. THERE COULD BE A STRAY
ISOLATED STORM THANKS TO A LONG TRAVELED GRAVITY WAVE BUT
PROBABILITY TOO LOW TO HOLD ON TO POPS FOR THE OVERNIGHT PERIOD. OF
NOTE...THE LATEST HRRR DOES DEVELOP SOME ACTIVITY OVER SOUTHEAST
ARIZONA WITH SOME VERY ISOLATED STORMS MAKING THEIR WAY INTO SOUTH-
CENTRAL ARIZONA LATE TONIGHT. LOCAL HI-RES MODELS AND 00Z NCAR
ENSEMBLE ARE NOT REFLECTING THAT. LATEST NAM AND GFS INDICATE SOME
RECOVERY OF MOISTURE SATURDAY AND THUS MORE STORMS THAN
TODAY...MAINLY OVER SOUTHEAST ARIZONA. ALSO SOME SOUTHERLY MID LEVEL
WINDS WHICH SHOULD BRING STORMS CLOSER TO THE PHOENIX AREA THAN
TODAY. NO CHANGES TO CURRENT FORECASTS.
&&
.PREVIOUS DISCUSSION ISSUED 152 PM...
AS EXPECTED THERE HAS BEEN A LATER ONSET TO STORM ACTIVITY TODAY
WITH ONLY A FEW SHOWERS AND THUNDERSTORMS IN NORTHERN YUMA COUNTY AND
SOUTHERN RIVERSIDE COUNTY. A FEW ADDITIONAL SHOWERS AND THUNDERSTORMS
ARE CURRENTLY SEEN OVER THE WHITE MOUNTAINS AND NORTH OF THE MOGOLLON
RIM OUTSIDE OF OUR CWA. A BOUNDARY LAYER AND DRYING NORTHERLY FLOW
ALOFT ARE LIMITING DEVELOPMENT CURRENTLY AND LIKELY THROUGH THE REST
OF TODAY. BEST CHANCES FOR THE REST OF TODAY WILL BE OVER HIGHER
TERRAIN AREAS OF SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA WHERE
PWATS ARE HIGHEST...WHILE LIMITED ACTIVITY ACROSS SOUTHEAST AND
SOUTH-CENTRAL ARIZONA SHOULD MOSTLY STAY OUTSIDE THE PHOENIX AREA.
A SLOW TRANSITION TO A DRIER REGIME IS EXPECTED THROUGH EARLY NEXT
WEEK...BUT STORM CHANCES WILL BE POSSIBLE BOTH SATURDAY AND SUNDAY AS
PWATS ARE FORECAST TO BE AROUND 1.25 INCHES. VERY WEAK FLOW ALOFT ON
SATURDAY POINT TOWARD A TYPICAL MONSOON DAY OVER SOUTH-CENTRAL AND
SOUTHEAST ARIZONA WITH HIGH TERRAIN STORMS FOLLOWED BY THE POTENTIAL
FOR A FEW STORMS OVER THE LOWER DESERTS FROM OUTFLOW INTERACTIONS.
FOR SUNDAY...PWATS START TO DROP BELOW ONE INCH OVER THE LOWER
COLORADO RIVER VALLEY...WHILE STILL REMAINING BETWEEN 1.25-1.40
INCHES OVER SOUTH-CENTRAL ARIZONA. MORE FAVORABLE DIFLUENT FLOW ALOFT
IS LIKELY ON SUNDAY OVER SOUTH-CENTRAL ARIZONA WHICH SHOULD LEAD TO
SLIGHTLY BETTER STORM CHANCES OVER THE LOWER DESERTS. TEMPERATURES
THROUGH THE WEEKEND WILL REMAIN QUITE WARM FOR THIS TIME OF YEAR AS
HIGHS LIKELY WILL BREACH 110 DEGREES IN OUR WESTERN ZONES AND IN A
104-109 RANGE OVER THE SOUTH-CENTRAL ARIZONA DESERTS.
THE DRYING TREND WILL GAIN STEAM STARTING MONDAY AND CONTINUE THROUGH
AT LEAST THE MIDDLE OF NEXT WEEK. UPPER TROFFING IS FORECAST TO SET
UP BOTH ALONG THE WEST COAST AND INLAND OVER THE PAC NORTHWEST AND
THIS WILL LEAD TO STRENGTHENING SOUTHWEST FLOW ALOFT TO WORK INTO THE
DESERT SOUTHWEST AND GRADUALLY THIN OUT THE MOISTURE OVER SE
CALIFORNIA AND THE LOWER AZ DESERTS. BY NEXT MONDAY THUNDERSTORM
CHANCES SHOULD BE CONFINED PRIMARILY TO HIGHER TERRAIN AREAS EAST OF
PHOENIX...ZONE 24 TO BE EXACT. THERE WILL BE PERIODS OF HIGH CLOUDS
MOVING THROUGH THE FLOW BUT OVERALL DESERTS SHOULD RANGE FROM MOSTLY
SUNNY TO PARTLY SUNNY EACH DAY FROM MONDAY ONWARD. AS THE UPPER
TROFFING DEVELOPS AND HEIGHTS FALL...HIGH TEMPERATURES WILL STEADILY
FALL OFF AND BY NEXT MONDAY THE WARMER LOWER DESERTS WILL BE WELL
UNDER 110. THE GREATER PHOENIX AREA IS FORECAST TO DROP TO 105 ON
MONDAY...AND EVENTUALLY TO 103 ON WEDNESDAY AND THURSDAY. THE 103
DEGREE READINGS WILL EQUAL THE CLIMATE NORMALS FOR THOSE DAYS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...AND..
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXCEPT FOR VERY ISOLATED THUNDERSTORMS OVER THE MOUNTAINS OF EASTERN
ARIZONA...EXPECT QUIET CONDITIONS THE REST OF THE NIGHT AND THROUGH
THE MORNING. RENEWED STORM DEVELOPMENT OVER HIGHER TERRAIN AND
SOUTHEAST ARIZONA SATURDAY AFTERNOON WITH ONLY A SLIGHT CHANCE OF
STORMS AT ANY GIVEN TAF SITE. OTHERWISE ONLY SOME HIGH CLOUDS ALONG
WITH FAMILIAR DIURNAL WIND PATTERNS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
DRIER AND WARMER WEATHER WILL GRADUALLY SPREAD INTO REGION FROM THE
WEST. A SLIGHT CHANCE OF AFTERNOON AND EVENING TSTMS WILL STILL BE
FORECAST FOR THE MOUNTAINS OF SOUTHERN GILA COUNTY EACH DAY. HIGH
TEMPERATURES THROUGH THE WEEK WILL BE NEAR NORMAL WITH HOTTER DESERT
LOCATIONS NEARING 110 ON MONDAY. MINIMUM HUMIDITIES WILL FALL INTO
THE 10 TO 15 PERCENT RANGE OVER THE WESTERN DESERTS BUT STAY MOSTLY
ABOVE 15 PERCENT ACROSS SOUTH CENTRAL ARIZONA EACH DAY WITH VALUES
REACHING 25 PERCENT IN SOUTHERN GILA COUNTY. AFTERNOON SOUTHWEST
WINDS WILL RANGE FROM 10 TO 20 MPH. GOOD OVERNIGHT RECOVERY IS
EXPECTED.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...KUHLMAN/CB
AVIATION...AJ
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
305 AM MST SAT AUG 29 2015
.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT WILL KEEP HIGH TEMPERATURES WELL ABOVE
SEASONAL NORMALS TODAY WITH HOTTER LOWER DESERTS REACHING OR
EXCEEDING 110. THERE WILL BE SUFFICIENT MOISTURE EAST OF THE LOWER
COLORADO RIVER TO SUPPORT ISOLATED TO SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THROUGH SUNDAY. STARTING MONDAY DRIER WESTERLY
FLOW ALOFT WILL PUSH THE MOISTURE OFF TO THE EAST LIMITING STORM
CHANCES PRIMARILY TO HIGHER TERRAIN AREAS TO THE EAST OF PHOENIX.
THERE WILL BE A GRADUAL COOLING TREND STARTING SUNDAY WITH CENTRAL
DESERTS HIGH TEMPERATURES DROPPING TO AROUND SEASONAL NORMALS BY THE
MIDDLE OF NEXT WEEK.
&&
.DISCUSSION... A STRONG UPPER LEVEL TROF CURRENTLY SPINNING OFF THE
PAC NW COAST HAS KEPT THE DOWNSTREAM UPPER RIDGE PUMPED UP OVER THE
DESERT SOUTHWEST...WITH H5 VALUES AROUND 593DM ACROSS ARIZONA PER
THE LATEST PLOT DATA. THE HIGH HEIGHTS ALOFT CONTINUED TO PRODUCE
HOT WEATHER ACROSS THE LOWER DESERTS WITH PHOENIX REACHING 109
YESTERDAY AND YUMA HITTING 111. LITTLE CHANGE IN THE PATTERN IS
EXPECTED TODAY AND CONTINUED HOT WEATHER IS ON TAP FOR THE LOWER
DESERTS...IN FACT PHOENIX IS EXPECTED TO REACH 110 TODAY WITH 110
PLUS READINGS OVER THE HOTTER WESTERN DESERTS. TEMPERATURES TODAY
WILL BE VERY CLOSE TO EXCESSIVE HEAT WARNING LEVELS.
WITH THE TROFFING SITTING OFF THE WEST COAST AND THE RIDGE PARKED
FIRMLY OVERHEAD...STEERING FLOW IS EITHER WEAK AND NONDESCRIPT OR
WEAK SOUTHERLY. PLENTY OF MOISTURE CONTINUES TO FLOW NORTH THRU
CENTRAL AND EASTERN ARIZONA WITH PWAT VALUES BETWEEN 1.25 AND 1.5
INCHES...AND SURFACE DEWPOINTS REMAIN HIGH AS WELL. AT 2 AM MOST OF
THE LOWER DESERTS RANGED FROM THE MID 50S TO THE MID 60S. EAST OF
THE LOWER COLORADO RIVER TODAY THERE WILL BE SUFFICIENT MOISTURE...
MLCAPE AND DAYTIME HEATING TO KEEP A THREAT GOING FOR AFTERNOON AND
EVENING STORMS...AND IN FACT SEVERAL LOCAL MESOSCALE MODELS
INCLUDING THE HRRR CALL FOR CONVECTION BREAKING OUT THIS AFTERNOON
OVER THE CENTRAL DESERTS...INCLUDING THE GREATER PHOENIX AREA...AND
PERSISTING INTO THE NIGHTTIME HOURS. POPS HAVE BEEN RAISED EAST OF
THE LOWER COLORADO RIVER INTO THE 15-20 PERCENT BALLPARK WITH
CHANCES FORECAST IN THE HIGHER TERRAIN EAST OF PHOENIX.
ON SUNDAY SIGNIFICANT SHORTWAVE ENERGY IS FORECAST TO MOVE INLAND
OVER THE PAC NORTHWEST AND IN RESPONSE FLOW OVER THE DESERT
SOUTHWEST AND ARIZONA BECOMES INCREASINGLY SOUTHWESTERLY. HEIGHTS
ALOFT FALL SLIGHTLY AND TEMPS SHOULD COOL A FEW DEGREES BUT THEY
WILL REMAIN WELL ABOVE NORMAL. THE FLOW WILL START TO SHIFT THE
DEEPER MOISTURE FURTHER TO THE EAST...BUT THERE WILL BE SUFFICIENT
MOISTURE AND INSTABILITY TO KEEP THE THREAT GOING FOR AFTN/EVE STORMS
ACROSS SOUTH CENTRAL ARIZONA. POPS WILL BE SIMILAR TO TODAY...BUT
SLIGHTLY LOWER WEST OF MARICOPA COUNTY.
GFS AND ECMWF OPERATIONAL RUNS AS WELL AS ENSEMBLE GUIDANCE CONTINUE
TO CALL FOR A GRADUAL DRYING AND COOLING TREND TO OCCUR OVER THE
ENTIRE WORK WEEK NEXT WEEK...AS TROFFING ALOFT INITIALLY DEVELOPS
ALONG THE WEST COAST AND PLACES A DRYING SOUTHWEST FLOW ALOFT ACROSS
SERN CALIFORNIA AND ARIZONA. AS THE WEEK PROGRESSES THE TROFFING
STARTS TO PUSH INLAND AND AS THIS HAPPENS TEMPERATURES WILL COOL
DOWN TO NEAR SEASONAL NORMALS. MONDAY INTO TUESDAY THE TROF AXIS
REMAINS ALONG THE WEST COAST...AND FLOW IS NOT SUFFICIENT TO
COMPLETELY SCOUR OUT THE MOISTURE OVER ALL OF SOUTH CENTRAL AZ. FOR
THE MOST PART THE THREAT OF AFTERNOON AND EVENING STORMS WILL BE
CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX BUT CHANCES IN THE
GREATER PHOENIX AREA WILL CERTAINLY NOT BE ZERO...THEY WILL HOVER IN
THE 5 TO 10 PERCENT BALLPARK. FOR THE LATTER HALF OF THE WORKWEEK AS
THE TROF AXIS SHIFTS INLAND AND SOUTHWEST FLOW ALOFT BECOMES
STRONGER...MOISTURE WILL BE PUSHED OFF TO THE EAST AND EVENTUALLY
ANY THREAT FOR STORMS WILL FOCUS OVER HIGHER TERRAIN AREAS TO THE
EAST OF GLOBE WITH SKIES IN THE GREATER PHOENIX AREA MOSTLY SUNNY
EACH DAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...AND..
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXCEPT FOR VERY ISOLATED THUNDERSTORMS OVER THE MOUNTAINS OF EASTERN
ARIZONA...EXPECT QUIET CONDITIONS THE REST OF THE NIGHT AND THROUGH
THE MORNING. RENEWED STORM DEVELOPMENT OVER HIGHER TERRAIN AND
SOUTHEAST ARIZONA SATURDAY AFTERNOON WITH ONLY A SLIGHT CHANCE OF
STORMS AT ANY GIVEN TAF SITE. OTHERWISE ONLY SOME HIGH CLOUDS ALONG
WITH FAMILIAR DIURNAL WIND PATTERNS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
DRIER AND WARMER WEATHER WILL GRADUALLY SPREAD INTO REGION FROM THE
WEST. A SLIGHT CHANCE OF AFTERNOON AND EVENING TSTMS WILL STILL BE
FORECAST FOR THE MOUNTAINS OF SOUTHERN GILA COUNTY EACH DAY. HIGH
TEMPERATURES THROUGH THE WEEK WILL BE NEAR NORMAL WITH HOTTER DESERT
LOCATIONS NEARING 110 ON MONDAY. MINIMUM HUMIDITIES WILL FALL INTO
THE 10 TO 15 PERCENT RANGE OVER THE WESTERN DESERTS BUT STAY MOSTLY
ABOVE 15 PERCENT ACROSS SOUTH CENTRAL ARIZONA EACH DAY WITH VALUES
REACHING 25 PERCENT IN SOUTHERN GILA COUNTY. AFTERNOON SOUTHWEST
WINDS WILL RANGE FROM 10 TO 20 MPH. GOOD OVERNIGHT RECOVERY IS
EXPECTED.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CB
AVIATION...AJ
FIRE WEATHER...DEWEY
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1122 PM MDT FRI AUG 28 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 242 PM MDT FRI AUG 28 2015
TODAY AN UPR RIDGE IS OVR UT AND WRN CO...WITH NW FLOW ALOFT OVR ERN
CO AND A WEAK UPR DISTURBANCE MOVING THRU THE NW FLOW OVR ERN CO AND
WRN KS. THE NAM AND HRRR SHOW ISOLD TO SCT CONVECTION OVR THE HYR
TRRN AND PORTIONS OF THE I-25 CORRIDOR THRU THIS EVENING...BUT THE
HRRR ALSO SHOWS THE POTENTIAL FOR A FEW SHOWERS/TSTMS OVR THE SERN
PLAINS AS WELL. HAVE ALREADY SEEN A FEW ECHOES DEVELOP OVR BACA AND
ERN LAS ANIMAS COUNTIES...SO WL KEEP SOME ISOLD POPS FOR THESE
LOCATIONS THIS EVENING...BUT WL KEEP SILENT POPS OVR THE REST OF THE
SERN PLAINS. THE DISTURBANCE WILL EXIT THE REGION IN THE
EVENING...AND PCPN CHANCES ACRS THE AREA ARE GENERALLY EXPECTED TO
END BY MIDNIGHT.
ON SATURDAY THE UPR RIDGE MOVES OVR THE AREA. WITH LIMITED
MOISTURE...ONLY ISOLD TO SCT PCPN CHANCES ARE EXPECTED OVR THE NR
THE HYR TRRN. HIGH TEMPS SATURDAY SHOULD BE AROUND TO SLIGHTLY
ABOVE AVERAGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 242 PM MDT FRI AUG 28 2015
MODELS IN DECENT AGREEMENT THROUGH THE EXTENDED PERIOD WITH LOW
ENSEMBLE SPREADS. THE UPPER PATTERN WILL REMAIN NEARLY STATIONARY
WITH RIDGING NORTHWARD OUT OF THE DESERT SOUTHWEST...STRETCHING
NORTHEAST INTO THE NORTHERN PLAINS...AND AN UPPER TROUGH SITS
ALONG THE WEST COAST. EXPECT PERSISTENT SOUTHWESTERLY FLOW ALONG
WITH MONSOONAL MOISTURE TO CONTINUE ACROSS COLORADO THROUGH THE
EXTENDED PERIOD. SHOWER AND THUNDERSTORM CHANCES WILL BE HIGHLY
DEPENDENT UPON EMBEDDED ENERGY IN THE SOUTHWEST FLOW. CURRENT
MODEL ANALYSIS BRINGS NEAR DAILY DISTURBANCES ACROSS THE AREA
SATURDAY NIGHT THROUGH TUESDAY. SHOWERS AND THUNDERSTORMS ARE
FORECAST TO DEVELOP OVER THE MOUNTAINS DURING THE AFTERNOON
HOURS...AND SPREAD EAST INTO THE I-25 CORRIDOR DURING THE EVENING
BEFORE DISSIPATING OVERNIGHT. THE GFS IS DRIER ON WEDNESDAY AND
THURSDAY...AND THE ECMWF IS COMPLETELY DRY THESE DAYS. FOR NOW
HAVE LOW POPS IN THE FORECAST FOR THE MOUNTAINS WEDNESDAY AND
THURSDAY. A STRONGER DISTURBANCE IS LIKELY TO MOVE NORTH OUT OF
THE DESERT SOUTHWEST ON FRIDAY...WITH AN UPTICK IN SHOWER AND
THUNDERSTORM ACTIVITY. SHOWERS AND THUNDERSTORMS WILL BE CAPABLE
OF PRODUCING LOCALLY HEAVY RAINFALL...AND FLASH FLOODING WILL
CONTINUE TO BE A THREAT...ESPECIALLY ON AREA BURN SCARS. TEMPERATURES
WILL REMAIN WARM THROUGH THE EXTENDED PERIOD WITH 80S AND 90S
ACROSS MUCH OF THE AREA FOR AFTERNOON HIGHS. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1119 PM MDT FRI AUG 28 2015
VFR CONDITIONS ARE ANTICIPATED DURING THE NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. WINDS WILL BE DIURNALLY DRIVEN.
THERE WILL BE A VERY SLIGHT CHANCE OF A -TSRA DURING THE AFTERNOON
AND EARLY EVENING HOURS AT ALL 3 TAF SITES...BUT PROBABILITY OF
OCCURRENCE IS TOO LOW TO EXPLICITLY MENTION IN TAF PRODUCT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
312 AM CDT SAT AUG 29 2015
.SHORT TERM...(TODAY)
ISSUED AT 312 AM CDT SAT AUG 29 2015
07Z/2AM SURFACE ANALYSIS SHOWS A WEAK FRONTAL BOUNDARY EXTENDING
FROM WISCONSIN SOUTHWESTWARD TO THE TEXAS PANHANDLE. A PLUME OF
MAINLY MID-LEVEL MOISTURE AHEAD OF THE FRONT HAS RESULTED IN
SCATTERED LIGHT SHOWERS/SPRINKLES ACROSS THE WESTERN HALF OF THE
KILX CWA EARLY THIS MORNING. 00Z UPPER AIR SOUNDING SHOWED PLENTY
OF DRY AIR BELOW 850MB...SO PRECIP HAS BEEN HAVING A HARD TIME
REACHING THE GROUND IN MANY AREAS. FORECAST SOUNDINGS SHOW A
GRADUAL MOISTENING OF THE PROFILE TODAY...HOWEVER DEEP-LAYER
MOISTURE REMAINS LACKING. IN ADDITION...WIDESPREAD CLOUD COVER WILL
LIMIT INSTABILITY...WITH GFS SBCAPE VALUES ONLY REACHING THE 500 TO
1000J/KG RANGE. END RESULT WILL BE SCATTERED SHOWERS WITH PERHAPS A
RUMBLE OF THUNDER. THINK AREAL COVERAGE OF PRECIP WILL REMAIN
LOW...SO WILL ONLY CARRY 30-40 POPS. HIGH TEMPERATURES WILL RANGE
FROM THE UPPER 70S ALONG/NORTHWEST OF THE ILLINOIS RIVER...TO THE
MIDDLE 80S ALONG/SOUTHEAST OF I-70 WHERE CONDITIONS WILL REMAIN DRY
UNTIL A FEW SHOWERS ARRIVE DURING THE AFTERNOON.
&&
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 312 AM CDT SAT AUG 29 2015
FRONTAL BOUNDARY WILL SLOWLY PUSH EASTWARD LATER TODAY INTO
TONIGHT...WITH MODEL CONSENSUS SHOWING IT REACHING A CHICAGO TO
KIRKSVILLE LINE BY 12Z SUN. SCATTERED SHOWERS WILL BE ONGOING
AHEAD OF THE FRONT ACROSS MUCH OF THE AREA THIS EVENING...THEN
WILL SHIFT TO MAINLY LOCATIONS ALONG/EAST OF I-57 OVERNIGHT. MAIN
WEATHER CONCERN FOR TONIGHT WILL BE THE POTENTIAL FOR FOG ACROSS
THE W/NW CWA. AS THE SLOW-MOVING FRONT ARRIVES...WINDS WILL BECOME
LIGHT/VARIABLE ACROSS THIS AREA. DUE TO THE NEARLY CALM
WINDS...ADDED LOW-LEVEL MOISTURE FROM SHOWERS TODAY...AND PARTIAL
CLEARING LATE TONIGHT...THINK AT LEAST PATCHY FOG WILL FORM. BOTH
FORECAST SOUNDINGS AND NUMERIC GUIDANCE SUGGEST A REDUCTION IN
VISBY OVERNIGHT. CURRENT OBSERVATIONS IN THE VICINITY OF THE FRONT
ACROSS IOWA SHOW WIDESPREAD FOG...WITH A FEW VISBYS DOWN TO AROUND
1/4 MILE. THINK THIS SAME SCENARIO WILL UNFOLD FURTHER EAST
TONIGHT...SO HAVE INCLUDED PATCHY FOG IN THE FORECAST WEST OF I-55
AFTER MIDNIGHT.
THE FRONTAL BOUNDARY WILL SLOWLY DISSIPATE ON SUNDAY...HOWEVER
ENOUGH UPPER-LEVEL SUPPORT WILL PERSIST TO SUPPORT AT LEAST A
MENTION OF A FEW SHOWERS/THUNDERSTORMS. MOST MODELS PRODUCE LIGHT
QPF ACROSS NEARLY THE ENTIRE CWA AS THE BOUNDARY HAS SLOWED SLIGHTLY
FROM PREVIOUS RUNS. AS A RESULT...HAVE PULLED POPS FURTHER WEST TO
INCLUDE SLIGHT CHANCES AS FAR WEST AS THE ILLINOIS RIVER SUNDAY
AFTERNOON/EVENING.
AFTER THAT...THE REMAINDER OF THE EXTENDED LOOKS WARM AND DRY AS
UPPER-LEVEL RIDGING DOMINATES THE EASTERN CONUS THROUGH THE END OF
THE COMING WEEK. A SLIGHT WEAKNESS IN THE RIDGE APPEARS TO DEVELOP
ACROSS ILLINOIS INTO THE OHIO RIVER VALLEY...POTENTIALLY TRIGGERING
ISOLATED AFTERNOON/EVENING CONVECTION TUESDAY THROUGH FRIDAY.
HOWEVER...MID-LEVEL WARMING BENEATH THE RIDGE WILL LIKELY LEAD TO
CAPPING AND AN OVERALL SUPPRESSION OF CONVECTION. AS A
RESULT...WILL MAINTAIN A DRY FORECAST WITH HIGH TEMPERATURES
CLIMBING INTO THE UPPER 80S TO AROUND 90 DEGREES EACH DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1142 PM CDT FRI AUG 28 2015
LOW PRESSURE CENTERED IN WESTERN IOWA WILL CONTINUE TO DRIFT EAST
TONIGHT. IT WILL GRADUALLY DISSIPATE NEAR WESTERN ILLINOIS
SATURDAY AFTERNOON/EVE. SHOWERS HAVE EXPANDED IN COVERAGE BETWEEN
04Z-05Z, AND RAIN IS STARTING TO REACH THE GROUND FROM CLOUD
BASES AT 8K FT OR HIGHER. SCATTERED RAIN SHOWERS WILL PERIODICALLY
AFFECT THE TERMINAL SITES OVER THE NEXT 18 HOURS, BEFORE
DISSIPATING SATURDAY EVENING. THE CHANCES ONLY WARRANTED A VCSH
AND VFR CLOUD COVER, BASED ON FORECAST SOUNDINGS FROM HRRR AND
RAP/NAM OUTPUT. USED ONLY VCSH IN ALL TAFS TO ACCOUNT FOR PRECIP,
AS TIMING WILL BE HIGHLY VARIABLE IN TERMS OF TIMING AND LOCATION.
ENDED ALL MENTION OF PRECIP BEFORE 00Z/30. WINDS ARE EXPECTED TO
REMAIN SOUTH THROUGH AT LEAST 18Z, THEN BEGIN TO SHIFT TO THE
SOUTHWEST AS THE LOW AND COLD FRONT APPROACH WESTERN ILLINOIS.
PREVAILING WIND SPEEDS SHOULD REMAIN 10KT OR LESS THROUGH TOMORROW
AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
207 AM CDT SAT AUG 29 2015
.UPDATE...
626 PM CDT
HAVE ADJUSTED POPS DOWNWARD THROUGH THE MID EVENING HOURS TO
ACCOUNT FOR RADAR AND NEAR-TERM GUIDANCE TRENDS. LEADING EDGE OF
SHORTWAVE TROUGH AND VORTICITY MAXIMA WILL MOVE EAST FROM
WISCONSIN THIS EVENING...KEEPING BEST FORCING FOR PRECIP NORTH OF
THE STATE LINE. THUS...JUST HAVE GENERALLY ISOLATED
SHRA/INTERMITTENT SPRINKLE MENTION THROUGH MID EVENING IN FAR
NORTHERN ILLINOIS. VERY DRY AIR NOTED AROUND 800 MB ON A RECENT
AMDAR SOUNDING FROM MDW WILL MAKE IT TOUGH FOR ANY STEADY PRECIP
UNTIL DRY AIR GETS ERODED. UPPER TROUGH/SHORTWAVE AXIS AND
SHEARED VORT MAX ALONG TROUGH AXIS WILL SLOWLY PROGRESS FROM IA TO
NORTHERN IL LATE THIS EVENING AND OVERNIGHT...BRINGING GRADUALLY
INCREASING SHRA/RAIN COVERAGE FROM NORTHWEST TO SOUTHEAST...BUT
MANY AREAS ALONG AND EAST OF AN EVANSTON TO PONTIAC LINE COULD
VERY WELL REMAIN DRY THROUGH DAYBREAK. VERY LITTLE IF ANY
INSTABILITY OVER AREA THROUGH THE NIGHT AND POOR MIDLEVEL LAPSE
RATES SUPPORT KEEPING SLIGHT CHANCE TSRA AT BEST. THE REST OF THE
FORECAST LOOKS TO BE ON TRACK.
RC
&&
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
307 PM CDT
SATURDAY NIGHT THROUGH FRIDAY...
THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE
FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE
EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT
WITH PREVIOUS RUNS.
THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR
NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL
THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE
SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW
THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL
SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS
OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP
OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED
SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE
PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH
MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID
ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL
HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD
FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST
MAY CAUSE SOME DELAY IN THE MOISTURE RETURN.
THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE
MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE
LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD
PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE
HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL
EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING
ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN
IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A
LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT
INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA
AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED
OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS
WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD
COVER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIOD OF RAIN OVERNIGHT INTO SATURDAY MORNING
* MVFR OR LOWER CIGS AND VSBY POSSIBLE SAT NIGHT
IZZI
//DISCUSSION...UPDATED 06Z...
WEAKENING STORM SYSTEM WILL BRING A PERIOD OF RAIN WITH POSSIBLE
PERIODIC MVFR VSBY LATE TONIGHT INTO SAT MORNING BEFORE RAIN
TAPERS OFF AND ENDS BY MIDDAY. SMALL CHANCE EXISTS FOR SOME ISOLD
SHRA OR PERHAPS A TSRA DURING THE LATE AFTERNOON AS WHAT IS LEFT
OF THE STORM SYSTEM FESTERS...BUT CHANCES LOOK TOO LOW TO INCLUDE
PRECIP IN TAFS AT THIS TIME. LIGHT EAST TO SOUTHEAST WINDS COULD
TURN MORE SOUTHERLY SAT MORNING BEFORE PROBABLY TURNING FAIRLY
LIGHT AND VARIABLE DURING THE AFTERNOON. SHOULD SEE A TENDENCY FOR
WINDS TO BECOME LIGHT NORTHEAST SAT NIGHT AND WITH AMPLE LOW LEVEL
MOISTURE AND RECENT RAINS COULD SEE SOME LIGHT FOG AND/OR STRATUS
DEVELOP.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN LATE TONIGHT/SAT MORNING
* HIGH CONFIDENCE IN WINDS BELOW 10KT...BUT LOW CONFIDENCE IN
DIRECTION.
* LOW CONFIDENCE IN CIGS/VSBY SAT NIGHT
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. EAST WIND.
MONDAY...VFR. SOUTHEAST WIND.
TUESDAY...VFR. SOUTH WIND.
WEDNESDAY...SLT CHC TSRA. PRIMARILY VFR. SOUTH WIND.
THURSDAY...VFR. SOUTH WIND.
BMD
&&
.MARINE...
207 AM CDT
NARROW RIDGE OF HIGH PRESSURE STRETCHING FROM NEAR DETROIT TO
GREEN BAY COMBINED WITH WEAKENING LOW PRESSURE OVER IOWA WILL
RESULT IN A NARROW RIBBON OF STRONGER EASTERLY WINDS EARLY THIS
MORNING OVER PORTIONS OF CENTRAL LAKE MICHIGAN BEFORE BACKING MORE
SOUTHEAST LATER THIS MORNING THEN ULTIMATELY EASING THIS
AFTERNOON. WEAK LOW OVER IOWA WILL DISSIPATE TONIGHT AND REMAINDER
OF THE UPCOMING WEEK WILL SEE WEATHER OVER THE LAKE DOMINATED BY
HIGH PRESSURE ANCHORED OVER THE MID ATLANTIC AND NORTHEAST.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
108 AM CDT SAT AUG 29 2015
.UPDATE...
HAVE ADJUSTED POPS DOWNWARD THROUGH THE MID EVENING HOURS TO
ACCOUNT FOR RADAR AND NEAR-TERM GUIDANCE TRENDS. LEADING EDGE OF
SHORTWAVE TROUGH AND VORTICITY MAXIMA WILL MOVE EAST FROM
WISCONSIN THIS EVENING...KEEPING BEST FORCING FOR PRECIP NORTH OF
THE STATE LINE. THUS...JUST HAVE GENERALLY ISOLATED
SHRA/INTERMITTENT SPRINKLE MENTION THROUGH MID EVENING IN FAR
NORTHERN ILLINOIS. VERY DRY AIR NOTED AROUND 800 MB ON A RECENT
AMDAR SOUNDING FROM MDW WILL MAKE IT TOUGH FOR ANY STEADY PRECIP
UNTIL DRY AIR GETS ERODED. UPPER TROUGH/SHORTWAVE AXIS AND
SHEARED VORT MAX ALONG TROUGH AXIS WILL SLOWLY PROGRESS FROM IA TO
NORTHERN IL LATE THIS EVENING AND OVERNIGHT...BRINGING GRADUALLY
INCREASING SHRA/RAIN COVERAGE FROM NORTHWEST TO SOUTHEAST...BUT
MANY AREAS ALONG AND EAST OF AN EVANSTON TO PONTIAC LINE COULD
VERY WELL REMAIN DRY THROUGH DAYBREAK. VERY LITTLE IF ANY
INSTABILITY OVER AREA THROUGH THE NIGHT AND POOR MIDLEVEL LAPSE
RATES SUPPORT KEEPING SLIGHT CHANCE TSRA AT BEST. THE REST OF THE
FORECAST LOOKS TO BE ON TRACK.
RC
&&
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
307 PM CDT
SATURDAY NIGHT THROUGH FRIDAY...
THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE
FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE
EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT
WITH PREVIOUS RUNS.
THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR
NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL
THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE
SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW
THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL
SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS
OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP
OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED
SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE
PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH
MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID
ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL
HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD
FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST
MAY CAUSE SOME DELAY IN THE MOISTURE RETURN.
THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE
MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE
LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD
PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE
HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL
EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING
ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN
IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A
LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT
INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA
AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED
OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS
WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD
COVER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIOD OF RAIN OVERNIGHT INTO SATURDAY MORNING
* MVFR OR LOWER CIGS AND VSBY POSSIBLE SAT NIGHT
IZZI
//DISCUSSION...UPDATED 06Z...
WEAKENING STORM SYSTEM WILL BRING A PERIOD OF RAIN WITH POSSIBLE
PERIODIC MVFR VSBY LATE TONIGHT INTO SAT MORNING BEFORE RAIN
TAPERS OFF AND ENDS BY MIDDAY. SMALL CHANCE EXISTS FOR SOME ISOLD
SHRA OR PERHAPS A TSRA DURING THE LATE AFTERNOON AS WHAT IS LEFT
OF THE STORM SYSTEM FESTERS...BUT CHANCES LOOK TOO LOW TO INCLUDE
PRECIP IN TAFS AT THIS TIME. LIGHT EAST TO SOUTHEAST WINDS COULD
TURN MORE SOUTHERLY SAT MORNING BEFORE PROBABLY TURNING FAIRLY
LIGHT AND VARIABLE DURING THE AFTERNOON. SHOULD SEE A TENDENCY FOR
WINDS TO BECOME LIGHT NORTHEAST SAT NIGHT AND WITH AMPLE LOW LEVEL
MOISTURE AND RECENT RAINS COULD SEE SOME LIGHT FOG AND/OR STRATUS
DEVELOP.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN LATE TONIGHT/SAT MORNING
* HIGH CONFIDENCE IN WINDS BELOW 10KT...BUT LOW CONFIDENCE IN
DIRECTION.
* LOW CONFIDENCE IN CIGS/VSBY SAT NIGHT
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. EAST WIND.
MONDAY...VFR. SOUTHEAST WIND.
TUESDAY...VFR. SOUTH WIND.
WEDNESDAY...SLT CHC TSRA. PRIMARILY VFR. SOUTH WIND.
THURSDAY...VFR. SOUTH WIND.
BMD
&&
.MARINE...
310 PM CDT
HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE
THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN
IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY
AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A
TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS
TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE
OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST
WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1142 PM CDT FRI AUG 28 2015
.UPDATE...
ISSUED AT 903 PM CDT FRI AUG 28 2015
THE DRY AIR IN PLACE ACROSS CENTRAL IL HAS CAUSED THE LEADING PUSH
OF SHOWERS TO DISSIPATE BEFORE REACHING THE ILLINOIS RIVER. THAT
SHOULD CONTINUE TO BE THE CASE UNTIL AT LEAST 06Z/1AM. WE EXPECT
BETTER POTENTIAL FOR RAIN TOMORROW AS THE LOW AND COLD FRONT
REACH WESTERN IL. THE WEAKENING OF THE ENTIRE LOW PRESSURE SYSTEM
AS IT REACHES ILLINOIS WILL SUPPORT KEEPING THE POPS IN THE LOW
CHANCE CATEGORY. WILL DIMINISH THE SOUTHERN EXTENT OF CHANCE POPS
BETWEEN 06Z AND 12Z, BASED ON TRENDS THIS EVENING. A VEIL OF HIGH
CLOUDS WILL KEEP LOW TEMPS WARMER THAN LAST NIGHT, WITH READINGS
MAINLY IN THE MID 60S. UPDATES THIS EVENING WILL BE MAINLY IN THE
WEATHER/POP AREA, AS THE REMAINDER OF THE FORECAST IS GENERALLY ON
TRACK.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 243 PM CDT FRI AUG 28 2015
AFTERNOON SURFACE MAP SHOWING LOW PRESSURE CENTERED NEAR OMAHA, WITH
A WARM FRONT EXTENDING NORTHEAST ACROSS IOWA AND A COLD FRONT INTO
CENTRAL KANSAS. MAIN ACTIVITY OF SHOWERS AND THUNDERSTORMS HAS BEEN
CLOSER TO THE WARM FRONT AND TRACKING NORTH OF OUR FORECAST AREA. A
GENERAL EASTWARD PROGRESSION OF THE BOUNDARIES IS EXPECTED OVER THE
NEXT SEVERAL HOURS, WITH THE COLD FRONT APPROACHING THE
ILLINOIS/IOWA BORDER TOWARD 3-4 AM. FORECAST SOUNDINGS ARE RATHER
DRY BELOW 12,000 FEET FROM ABOUT PEORIA EAST AND SOUTH, AND AM
STARTING TO GET CONCERNED THAT THERE WILL BE LITTLE MORE THAN
ISOLATED SHOWERS BETWEEN I-55 AND THE ILLINOIS RIVER TONIGHT.
HOWEVER, THE HRRR AND ARW MODELS ARE A BIT MORE AGGRESSIVE WITH
SHOWERS MOVING INTO THIS AREA AFTER 3 AM, SO WILL MAINTAIN CHANCE
POP`S ACROSS THE ILLINOIS RIVER VALLEY MAINLY FROM LATE EVENING
THROUGH OVERNIGHT. INSTABILITY IS A LITTLE MORE SPARSE THOUGH, WITH
THE CURRENT THUNDER ACTIVITY MAINLY NEAR THE UPPER LEVEL DISTURBANCE
TRACKING ACROSS CENTRAL IOWA, AND HAVE TRIMMED BACK THE THUNDER
POTENTIAL TO MAINLY WEST OF THE RIVER. OTHERWISE, HAVE MAINLY GONE
DRY EAST OF I-55. MILDER CONDITIONS EXPECTED OVERNIGHT WITH CLOUD
COVER MUCH MORE EXTENSIVE AND A SOUTHERLY FLOW, WITH MOST AREAS
DIPPING INTO THE MID 60S.
.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 243 PM CDT FRI AUG 28 2015
LOW PRESSURE AREA AND ASSOCIATED FRONT WEST OF THE AREA WILL
CONTINUE TO SLOWLY MOVE EAST AND INTO THE CWA DURING THE WEEKEND.
HOWEVER...VERY LITTLE SUPPORT FOR THIS SYSTEM AS IT MOVES EAST SO
ALL MODELS HAVE THIS SYSTEM WEAKENING AS IT MOVES INTO THE AREA.
THEREFORE...WILL ONLY HAVE CHANCE POPS FOR SAT MORNING WEST OF I-55
AND THEN MOVE POPS EAST DURING THE AFTERNOON BUT REMAINING MAINLY
NORTH OF I-70 AS FRONT CONTINUES TO WEAKEN AND BECOME SOMEWHAT
PARALLEL TO THE FLOW AND VERY LACKING ON CONVERGENCE/SUPPORT. CHANCE
POPS FOR SAT NIGHT WILL CONTINUE AS THE UPPER LEVEL WAVE SHIFTS EAST
ACROSS THE AREA. PCPN WILL BE MAINLY SHOWERS AND ISOLATED
THUNDERSTORMS...DUE TO LACK OF FORCING AND INSTABILITY. BY
SUNDAY...THE WAVE SHOULD BE VERY WEAK AND EAST OF THE CWA...SO WILL
ONLY HAVE SLIGHT CHANCE POPS. FOR REMAINDER OF THE WEEKEND AND INTO
THE BEGINNING OF NEXT WEEK...DRY CONDITIONS CAN BE EXPECTED AS HIGH
PRESSURE BEGINS TO BUILD IN THE WEST AND PUSH INTO THE NORTHERN PART
OF THE AREA.
BEGINNING TUE AND THROUGH MOST OF THE WEEK...A COUPLE OF MODELS
BRING REMNANTS OF TS ERIKA INTO THE AREA. HOWEVER...THIS IS
DEPENDENT ON WHERE THE TS GOES. AND IT IS FAR ENOUGH AWAY IN TIME
THAT WILL JUST KEEP CLOSE TO WHAT THE CRINT HAS...AND THAT IS JUST
SLIGHT CHANCE POPS IN SOME AREAS FOR WED THROUGH THUR. SLIGHT CHANCE
POPS WILL BE IN THE GRIDS BUT NOT MENTIONED IN THE WORDED FORECAST.
TEMPS THROUGH THE WEEKEND WILL BE TEMPERED DUE TO CLOUD COVER AND
SCATTERED PCPN...BUT STILL EXPECTING THEM TO RISE INTO THE 80S FOR
THE WEEKEND. BY NEXT WEEK...WITH UPPER LEVEL RIDGING BUILDING INTO
THE AREA AND DEWPOINTS BEING DRIER...EXPECTING TEMPS TO RISE INTO
THE UPPER 80S TO AROUND 90 FOR THE ENTIRE WEEK. THIS WILL BE MUCH
ABOVE NORMAL FOR THE BEGINNING OF SEPT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1142 PM CDT FRI AUG 28 2015
LOW PRESSURE CENTERED IN WESTERN IOWA WILL CONTINUE TO DRIFT EAST
TONIGHT. IT WILL GRADUALLY DISSIPATE NEAR WESTERN ILLINOIS
SATURDAY AFTERNOON/EVE. SHOWERS HAVE EXPANDED IN COVERAGE BETWEEN
04Z-05Z, AND RAIN IS STARTING TO REACH THE GROUND FROM CLOUD
BASES AT 8K FT OR HIGHER. SCATTERED RAIN SHOWERS WILL PERIODICALLY
AFFECT THE TERMINAL SITES OVER THE NEXT 18 HOURS, BEFORE
DISSIPATING SATURDAY EVENING. THE CHANCES ONLY WARRANTED A VCSH
AND VFR CLOUD COVER, BASED ON FORECAST SOUNDINGS FROM HRRR AND
RAP/NAM OUTPUT. USED ONLY VCSH IN ALL TAFS TO ACCOUNT FOR PRECIP,
AS TIMING WILL BE HIGHLY VARIABLE IN TERMS OF TIMING AND LOCATION.
ENDED ALL MENTION OF PRECIP BEFORE 00Z/30. WINDS ARE EXPECTED TO
REMAIN SOUTH THROUGH AT LEAST 18Z, THEN BEGIN TO SHIFT TO THE
SOUTHWEST AS THE LOW AND COLD FRONT APPROACH WESTERN ILLINOIS.
PREVAILING WIND SPEEDS SHOULD REMAIN 10KT OR LESS THROUGH TOMORROW
AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1255 AM EDT SAT AUG 29 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 313 PM EDT FRI AUG 28 2015
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH TONIGHT. A
WEAK FRONTAL SYSTEM WILL SETTLE INTO THE OHIO VALLEY THIS WEEKEND.
HIGH PRESSURE WILL BUILD BACK INTO THE AREA FOR THE EARLY NEXT WEEK.
A FEW DISTURBANCES MAY MOVE THROUGH CENTRAL INDIANA THROUGH THE
MIDDLE TO END OF THE NEXT WORK WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 948 PM EDT FRI AUG 28 2015
UPPED CLOUDS A BIT IN THE WEST TONIGHT BASED ON LATEST TRENDS SEEN
ON SATELLITE. HRRR TRIES TO BRING IN A FEW SHOWERS LATE TONIGHT BUT
DO NOT BELIEVE THERE WILL BE ENOUGH FORCING TO GENERATE MUCH RAIN.
CANNOT RULE OUT A FEW SPRINKLES AS DYING SHOWERS MOVE IN LATE...BUT
NOT ENOUGH EXPECTED TO ADD THESE TO THE FORECAST.
TEMPERATURE FORECAST LOOKS GOOD.
PREVIOUS DISCUSSION FOLLOWS...
WILL KEEP THE FORECAST DRY FOR TONIGHT AS SURFACE HIGH PRESSURE
HOLDS ON. SHORT TERM MODELS AND LATEST TRENDS TO THE WEST INDICATE
THERE WILL BE A GRADUAL INCREASE OF MID AND HIGH LEVEL CLOUD COVER.
A MOS BLEND FOR LOWS LOOKS REASONABLE GIVEN THE EXPECTED CLOUD COVER
FOR LOW TEMPERATURES 60-65.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 313 PM EDT FRI AUG 28 2015
MODELS REMAIN INCONSISTENT WITH REGARD TO MOISTURE AMOUNTS AND TRACK
OF A WEAK FRONTAL SYSTEM...WHICH IS ASSOCIATED WITH AN UPPER TROUGH
AND EXPECTED TO MOVE THROUGH THIS WEEKEND. INSTABILITY IS NOT GREAT
BUT AT LEAST WARRANTS MENTION OF SCATTERED THUNDERSTORMS DURING THIS
WEEKEND. BEST CHANCES APPEAR TO BE SATURDAY EVENING WHEN THE FRONTAL
SYSTEM IS PROJECTED TO CROSS THE AREA. WEAK CHANCES WILL EXIST
SATURDAY AFTERNOON AND AGAIN ON SUNDAY INTO SUNDAY NIGHT. SINCE THE
MODELS HAVE YET TO COME TO A CONSENSUS SOLUTION AND REMAIN
INCONSISTENT...KEPT CHANCES BELOW THE "LIKELY" CATEGORY...FOR NOW.
PRECIP CHANCES WILL QUICKLY BEGIN TO DWINDLE BY EARLY MONDAY
MORNING AS A RIDGE OF HIGH PRESSURE QUICKLY REESTABLISHES ITS
HOLD OVER THE REGION. DRY CONDITIONS ARE GENERALLY EXPECTED TO
KICK OFF THE WORK WEEK. AND TEMPERATURES WILL HAVE SLOWLY
ACCLIMATED BACK TO SEASONAL NORMAL BY MONDAY. WELCOME BACK
SUMMER...
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 252 PM EDT FRI AUG 28 2015
BROAD UPPER RIDGING WILL BE ACROSS THE AREA DURING THE LONG TERM.
HOWEVER THE INFLUENCE OF MOISTURE FROM ERIKA NOW LOOKS LIKE IT COULD
COME INTO PLAY IN THE MIDWEST/OHIO VALLEY DURING THE WEEK. WITH
MODELS TRENDING TOWARD BRINGING SOME ENERGY AROUND THE UPPER RIDGE
AND BRING MOISTURE NORTH THOUGHT IT PRUDENT TO FOLLOW THAT TREND AND
INCLUDE SOME SLIGHT CHANCES FOR THUNDERSTORMS DURING THE DAY FROM
WEDNESDAY THROUGH FRIDAY. THE INITIALIZATION FOLLOWED THIS TREND AS
WELL AND JUST NEEDED SOME QUALITY CONTROL TWEAKS. TEMPERATURE-WISE
LOOKING AT HIGHS JUST ABOVE NORMAL IN THE MID TO UPPER 80S FROM THE
INITIALIZATION AND THESE LOOK GOOD. HIGHS IN THE 90S NOT OUT OF THE
QUESTION BUT SHOULD ONLY BE ATTAINABLE IF THE TROPICAL MOISTURE
DOESN/T MAKE IT THIS WAY.
&&
.AVIATION /DISCUSSION FOR 290600Z TAF ISSUANCE/...
ISSUED AT 1235 AM EDT SAT AUG 29 2015
OUTSIDE OF ANY CONVECTION LATE IN THE PERIOD...VFR EXPECTED THROUGH
THE PERIOD.
MID CLOUD WILL CONTINUE TO INCREASE OVERNIGHT. THIS SHOULD KEEP FOG
AT BAY...BUT IF BREAKS LAST LONG ENOUGH...COULD SEE SOME MVFR FOG AT
THE OUTLIER SITES.
SCATTERED LIGHT SHOWERS ARE POSSIBLE SATURDAY MORNING...BUT BETTER
CHANCES FOR SCATTERED CONVECTION ARRIVE LATE AFTERNOON INTO THE
EVENING. FOR NOW HAVE ADDED A PROB30 GROUP FOR STORMS THEN.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF/50
SHORT TERM...SMF
LONG TERM....CP
AVIATION...50/JH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1139 PM CDT FRI AUG 28 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 358 PM CDT FRI AUG 28 2015
HEAVY RAIN WILL PERSIST ACROSS THE NORTHEAST THROUGH THE
EVENING. LATEST HRRR RUN KEEPS CONVECTION GOING IN THE FAR EAST
THROUGH 04-05Z TIME FRAME AND LEANED TOWARD THIS SOLUTION FOR
POPS/WX. THE WARM RAIN PROCESSES CURRENTLY AFFECTING THE FLASH FLOOD
WARNED AREAS ARE PRODUCING 2-4 INCH PER HOUR RAINFALL RATES. STRONG
DEEP MOISTURE CONVERGENCE OVER THE WATERLOO AREA WITH ROUGHLY 1.5-2
INCH PRECIPITABLE WATER AND WARM CLOUD DEPTHS TO AROUND 4000 METERS
IS ENOUGH TO CONTINUE THE HEAVY RAIN THREAT BEFORE SURFACE LOW IN
WESTERN IOWA PUSHES FURTHER EAST LATER THIS EVENING. POTENTIAL FOR
HEAVY RAIN TO CONTINUE IN THE EAST TO NORTHEAST SECTIONS OF THE
FORECAST AREA THROUGH 03Z TONIGHT...TO COINCIDE WITH THE LATEST HRRR
THINKING. OTHER CONCERN IS FOG OVERNIGHT WITH PLENTY OF MOISTURE AND
VERY LITTLE FLOW AT THE SURFACE A WEAK SURFACE RIDGE BUILDS INTO
WESTERN IOWA. HAVE MENTIONED PATCHY FOG PAST 09Z WEST OF I-35.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 358 PM CDT FRI AUG 28 2015
THE WEATHER WILL GENERALLY BE QUIET IN THE LONGER TERM WITH UPPER
RIDGING BUILDING INTO THE CENTRAL UNITED STATES. THICKNESSES WILL
INCREASE WITH TEMPERATURES CORRESPONDINGLY RESPONDING WITH HIGHS
CLIMBING ABOVE NORMAL...LIKELY TOWARD 90 BY EARLY NEXT
WEEK...ESPECIALLY IN THE SOUTH AND WEST. BOTH GFS AND EURO
INDICATED A WEAK SYSTEM PULLING NORTHEAST ON TUESDAY INTO THE
PLAINS WHICH MAY BRING THE THREAT OF ISOLATED THUNDER INTO THE
NORTHWEST PORTIONS OF IOWA BY LATER IN THE DAY INTO TUESDAY NIGHT.
OTHERWISE...THE RIDGE WILL REMAIN IN PLACE INTO LATE IN THE WEEK
WITH THE VERY WARM TEMPERATURES AND LITTLE THREAT OF PRECIPITATION.
&&
.AVIATION...29/06Z
ISSUED AT 1139 PM CDT FRI AUG 28 2015
SFC LOW STILL HAS SHIFTED TO SCEN IA AND WILL CONTINUE TO SHIFT EAST
THROUGH 12Z. LIGHT PRECIP WILL CONTINUE OVER THE FAR EASTERN TAF
LOCATIONS FOR A COUPLE MORE HOURS. MAIN CONCERN OVER IS IFR/LIFR
CIGS AND FOG POTENTIAL WITH HALF MILE VSBYS AND LOCALLY A QUARTER OR
LESS VSBY POSSIBLE. LOW CLOUDS AND FOG WILL SLOWLY BURN OFF THROUGH
LATE MORNING. A COUPLE MODELS HINT AT THE COLD FRONT DEVELOPING
STORMS DURING PEAK HEATING MAINLY AFFECTING KOTM BUT CONFIDENCE IN
THIS OCCURRING AT THIS POINT IS LOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
306 AM EDT SAT AUG 29 2015
.SHORT TERM (NOW THROUGH SUNDAY)...
ISSUED AT 235 AM EDT SAT AUG 29 2015
EARLY MORNING WATER VAPOR IMAGERY COMBINED WITH 500 MB HEIGHTS
SHOWED A MID LEVEL TROUGH EXTENDING FROM THE CENTRAL PLAINS
NORTHEASTWARD TOWARD EASTERN WISCONSIN...WHILE A BROAD CLOSED LOW
WAS ADVANCING NORTHWARD FROM THE GULF INTO THE DEEP SOUTH. THE
LOWER OHIO VALLEY LIED IN BETWEEN...AS OBSERVED BY IR SATELLITE
IMAGERY WHICH SHOWED MOSTLY CLEAR SKIES AND LIGHT WINDS. DEEPER
MOISTURE...CLOUDY SKIES...AND LIGHT RADAR RETURNS WERE OFF TO THE
NORTHWEST.
THE MAIN FORECAST CONCERN FOR TODAY IS PRECIPITATION CHANCES AS THE
TWO AFOREMENTIONED SYSTEMS TRACK TOWARD EACH OTHER. THE SOUTHERN
SYSTEM WILL DRAW MORE MOISTURE INTO THE AREA...CHARACTERIZED BY
DEWPOINTS APPROACHING THE UPPER 60S TO NEAR 70 THIS AFTERNOON. THE
NORTHERN SYSTEM WILL BEGIN TO WASH OUT AS IT SLOWLY ADVANCES
EASTWARD. OVERALL...DYNAMICS ARE RATHER WEAK WITH THESE SYSTEMS BUT
A WEAKLY OR UNCAPPED ENVIRONMENT ALONG WITH PEAK HEATING GENERATING
POCKETS OF INSTABILITY SHOULD BREAK OUT ISOLATED TO SCATTERED NON
SEVERE SHOWERS AND STORMS.
NEAR TERM HI-RES MODELS SHOW HIGH AGREEMENT SPATIALLY...TEMPORALLY
AND RUN TO RUN WHICH LEADS TO A HIGHER CONFIDENCE FORECAST FOR
TODAY. THE HRRR HAS BEEN VERY CONSISTENT SHOWING ISOLATED
SHOWERS/STORMS BREAKING OUT DURING THE EARLY AFTERNOON HOURS AS
CONVECTIVE TEMPS ARE REACHED. THE NSSL AND SPC WRF SOLUTIONS OFFER
SIMILAR SOLUTIONS AS WELL. THE HIGHEST COVERAGE LOOKS TO BE ALONG A
BOWLING GREEN TO FRANKFORT LINE AND WESTWARD...ALONG THE AXIS OF
GREATER INSTABILITY AND MOISTURE.
MOSTLY SUNNY SKIES THIS MORNING WILL BE REPLACED BY SCATTERED
CUMULUS AS WELL AS MID/HIGH CLOUDS...WHICH SHOULD MAKE FOR A PARTLY
TO MOSTLY CLOUDY AFTERNOON AT TIMES. PLAN ON HIGHS TO TOP OUT IN THE
MID TO UPPER 80S. THE INCREASE IN DEWPOINTS WILL MAKE IT FEEL
SLIGHTLY MORE MUGGY THAN RECENT DAYS.
EXPECTING A DROP OFF IN PRECIPITATION THIS EVENING WITH THE LOSS OF
HEATING...THOUGH WILL STILL CARRY A CHANCE THROUGH THE OVERNIGHT
WITH THE WEAK TROUGH OVERHEAD. SUNDAY STILL LOOKS TO BE THE BETTER
DAY FOR PRECIPITATION AS WE`LL HAVE A MORE FAVORABLE ENVIRONMENT AND
OVERALL DYNAMICS. PRECIPITATION COVERAGE STILL LOOKS TO BE
SCATTERED...SO KEPT CHANCES IN THE 30-40 PERCENT RANGE.
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
ISSUED AT 300 AM EDT SAT AUG 29 2015
MONDAY - WEDNESDAY...
A WEAK UPPER LOW NEAR THE OHIO VALLEY MAY PROVIDE ENOUGH SUPPORT FOR
ISLD SHOWERS/STORMS MAINLY ALONG AND EAST OF I-65 SUNDAY NIGHT AND
MONDAY. THE GFS IS MOST OPTIMISTIC WITH THIS CONVECTION AND EVEN
THIS NOTORIOUSLY WET MODEL ISN`T SHOWING MUCH PRECIP.
TUESDAY LOOKS TO BE DRY WITH THE NEXT CHANCE FOR SHOWERS/STORMS
ARRIVING FOR WED. MID RANGE MODELS ARE DIFFERENT IN DEPICTING THE
MAIN SOURCE FOR FORCING/MOISTURE. THE GFS INDICATES THE REMNANTS OF
T.S. ERIKA WILL BE THE CAUSE WHILE THE ECMWF SUGGESTS A NORTHERN
STREAM TROUGH WILL BE THE CAUSE. EITHER WAY WILL CARRY 20-30% POPS
FOR WED.
TEMPS FOR EARLY TO MID WEEK WILL BE ON THE INCREASE BACK TO SEASONAL
NORMS WITH HIGHS RANGING MAINLY THE MID TO UPPER 80S WITH A FEW
LOCATIONS NEAR 90 TUES/WED.
THURSDAY - FRIDAY...
LONG RANGE MODELS AGREE THAT A STRONG UPPER RIDGE AXIS WILL BUILD
INTO PORTIONS OF THE PLAINS/MIDWEST. THICKNESSES WILL INCREASE OVER
THE OHIO VALLEY AS A RESULT BRINGING TEMPS SLIGHTLY ABOVE NORMAL FOR
THE LATTER HALF OF THE WEEK (UPPER 80S/LOWER 90S FOR HIGHS).
ALTHOUGH A CLEAR TRIGGER IS NOT APPARENT, SOME LONG RANGE SIGNALS
SUGGEST A DIRTY RIDGE WITH SUBTLE WAVES MAY CAUSE MAINLY DIURNAL
CONVECTION PEAKING DURING THE AFTERNOON/EVENING HOURS BOTH
THURS/FRI. THUS WILL HAVE LOW POPS BOTH OF THESE DAYS.
&&
.AVIATION (06Z TAF UPDATE)...
ISSUED AT 104 AM EDT SAT AUG 29 2015
A LIGHT WIND COMBINED WITH PASSING HIGH CLOUDS SHOULD LIMIT FOG
POTENTIAL AT BWG/LEX THROUGH EARLY THIS MORNING. OTHERWISE...PLAN ON
VFR CONDITIONS AT ALL SITES AS SOUTHERLY WINDS DEVELOP BY MID-
MORNING ALONG WITH A SCATTERED CU FIELD WITH BASES 4-5 KFT. THERE
ARE SIGNALS FOR ISOLATED TO SCATTERED SHOWERS OR A STORM
DEVELOPING BY 17-18Z...LASTING THROUGH ABOUT 23-00Z.
THOUGH...EXPECTING LOW COVERAGE WHICH PRECLUDES MENTIONING IN THE
TAF FOR NOW. WINDS WILL REMAIN SOUTHERLY THROUGH THE END OF THE
TAF PERIOD WITH PASSING SCATTERED/BROKEN HIGH CLOUDS.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........ZBT
LONG TERM.........AMS
AVIATION..........ZBT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
329 AM EDT SAT AUG 29 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 411 PM EDT FRI AUG 28 2015
WV IMAGERY AND RAP ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL
FLOW ALONG THE US/CANADIAN BORDER. A SHORTWAVE TROUGH FROM NW
ONTARIO INTO NRN MN SUPPORTED SCT SHRA/TSRA OVER THE MN ARROWHEAD
INTO NRN ONTARIO WEST OF THUNDER BAY. TO THE SOUTH...ANOTHER SHRTWV
OVER IA BRINGING SHOWERS FROM NE IA THROUGH SW WI WAS SLOWLY LIFTING
TO THE ENE. THE LEADING EDGE OF THE PCPN TO NEAR AUW.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES PREVAILED ACROSS UPPER MI
WITH TEMPS IN THE MID 70S.
TONIGHT...MOST OF THE CWA WILL REMAIN BETWEEN THE INFLUENCE OF THE
NRN AND SRN STREAM SHORTWAVES. RADAR TRENDS AND SHORT RANGE MODELS
SUGGEST THAT THE RAIN OVER WI TO AFFECT MAINLY THE SRN TIER ALONG
AND SOUTH OF US-2 FROM IMT EASTWARD. SHRA/TSRA WITH THE NRN STREAM
SHRTWV MAY BRUSH MAINLY THE KEWEENAW BY LATE THIS EVENING AND
POSSIBLY INTO THE NRN PORTION OF UPPER MI. FCST MUCAPE VALUES INTO
THE 500-1000 J/KG RANGE OVER THE NORTH COULD ALSO SUPPORT ISOLD
TSRA.
SATURDAY...SOME SHOWERS MAY LINGER OVER THE SE PORTION OF THE CWA
ASSOCIATED WITH REMNANTS OF THE WI SHRTWV OR POSSIBLY AIDED BY A
TRAILING SHRTWV DIVING INTO NRN WI. HOWEVER...EXPECT THE PCPN TO
SLIDE OFF TO THE EAST BY AFTERNOON. WITH SOME CLEARING INTO THE WEST
HALF BY AFTERNOON...TEMPS WILL REBOUND INTO THE MID AND UPPER 70S.
GREATER CLOUD COVER OVER THE EAST AND WITH SRLY FLOW OFF OF LAKE
MI...TEMPS WILL REMAIN IN UPPER 60S AND LOWER 70S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT AUG 29 2015
MODELS INDICATE RIDGE MOVING IN FROM THE NORTHERN PLAINS WILL
PROVIDE DRY WEATHER FOR THE EARLY PART OF NEXT WEEK....THEN A SERIES
OF WEAKER SHORTWAVES MOVING UP THE BACKSIDE OF RIDGE COULD BRING
SOME ISOLD TO SCT CONVECTION INTO THE UPPER GREAT LAKES BY MIDWEEK.
MODELS THEN SUGGEST MID-UPPER LEVEL RIDGE COULD REESTABLISH ITSELF
IN DEVELOPING BLOCKING PATTERN OVER NORTH AMERICA AND GREATLY
AMPLIFY INTO THE UPPER GREAT LAKES BY THE END OF NEXT WEEK/WEEKEND.
WELL ABOVE NORMAL TEMPS LOOK LIKE A GOOD BET THROUGH MUCH OF THE
WEEK WITH THE POTENTIAL FOR NEAR RECORD WARM TEMPS LATE IN THE WEEK.
SUN AND MON...MODELS SHOW NORTHERN PLAINS RIDGE MOVING INTO THE
UPPER GREAT LAKES IN RESPONSE TO BROAD TROUGH DEVELOPING OVER WRN
CANADA INTO THE PAC NW. WITH 8H TEMPS RISING TO AROUND 20C AND DEW
POINTS IN THE LOWER 60S IN A SW FLOW...EXPECT MUGGY CONDITIONS
WITH HIGH TEMPS BY MONDAY TO REACH INTO THE LOWER TO MID 80S.
TUE INTO THU...MODELS ADVERTISE A SERIES OF SHORTWAVES MOVING UP
BACKSIDE OF MID-UPPER LEVEL RIDGE AS RIDGE AXIS PUSHES EAST OF THE
WESTERN GREAT LAKES. SINCE TIMING OF THESE WEAKER SHORTWAVES IS
POORLY RESOLVED BY MODELS WILL CONTINUE TO INCLUDE ONLY LOW CHC POPS
FOR POSSIBLE CONVECTION FROM THESE FEATURES THROUGH THE PERIOD.
TOWARD END OF NEXT WEEK/WEEKEND...MODELS SUGGEST RIDGE MID-UPPER
LEVEL RIDGE WILL REESTABLISH ITSELF AND GREATLY AMPLIFY INTO THE
CENTRAL CONUS AND GREAT LAKES REGION AS A BLOCKING PATTERN DEVELOPS
WITH A BROAD TROUGH PERSISTING OVER WRN CANADA INTO THE U.S. WEST
COAST AND A CUT-OFF LOW DEVELOPING NEAR THE CANADIAN MARITIMES OVER
THE NORTH ATLANTIC. WITH MANY OF THE MODELS FORECASTING 5H HEIGHTS
OF 590 DM OR GREATER AND 8H TEMPS GREATER THAN 20C...EXPECT HIGH
TEMPS WELL INTO THE 80S AND PERHAPS EVEN APPROACHING 90F OVER
PORTIONS OF THE WEST HALF OF UPPER MI. WOULD NOT BE SURPRISED TO SEE
A FEW RECORD HIGH TEMPS FALL FRI INTO SAT OVER THE WEST HALF OF THE
CWA. MUGGY CONDITIONS WILL CONTINUE WITH DEWPOINTS IN THE LOWER TO
MID 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 128 AM EDT SAT AUG 29 2015
VFR CONDITIONS WILL CONTINUE THROUGH THIS FCST PERIOD AT ALL SITES.
POSSIBLE ISOLD TSRA COULD AFFECT KCMX TERMINAL EARLY THIS MORNING AS
CLUSTERS OF TSRA OVER WESTERN LK SUPERIOR SLIDE TOWARD KEWEENAW
PENINSULA WHILE WEAKENING. WILL MONITOR AND UPDATE AS NECESSARY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT FRI AUG 28 2015
EXPECT A PERIOD OF MODERATE SW WINDS LATE TONIGHT INTO EARLY SATURDAY
GUSTING TO 15-20 KNOTS. OTHERWISE...A GENERALLY WEAK PRES GRADIENT
WILL DOMINATE THE UPPER LAKES INTO EARLY NEXT WEEK. ON MOST
DAYS...WINDS WILL BE UNDER 15KT. LOOKS LIKE THE LIGHTEST WINDS WILL
OCCUR OVER THE WEEKEND WITH HIGH PRES RIDGE MORE FIRMLY IN CONTROL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLA
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT SAT AUG 29 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 411 PM EDT FRI AUG 28 2015
WV IMAGERY AND RAP ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL
FLOW ALONG THE US/CANADIAN BORDER. A SHORTWAVE TROUGH FROM NW
ONTARIO INTO NRN MN SUPPORTED SCT SHRA/TSRA OVER THE MN ARROWHEAD
INTO NRN ONTARIO WEST OF THUNDER BAY. TO THE SOUTH...ANOTHER SHRTWV
OVER IA BRINGING SHOWERS FROM NE IA THROUGH SW WI WAS SLOWLY LIFTING
TO THE ENE. THE LEADING EDGE OF THE PCPN TO NEAR AUW.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES PREVAILED ACROSS UPPER MI
WITH TEMPS IN THE MID 70S.
TONIGHT...MOST OF THE CWA WILL REMAIN BETWEEN THE INFLUENCE OF THE
NRN AND SRN STREAM SHORTWAVES. RADAR TRENDS AND SHORT RANGE MODELS
SUGGEST THAT THE RAIN OVER WI TO AFFECT MAINLY THE SRN TIER ALONG
AND SOUTH OF US-2 FROM IMT EASTWARD. SHRA/TSRA WITH THE NRN STREAM
SHRTWV MAY BRUSH MAINLY THE KEWEENAW BY LATE THIS EVENING AND
POSSIBLY INTO THE NRN PORTION OF UPPER MI. FCST MUCAPE VALUES INTO
THE 500-1000 J/KG RANGE OVER THE NORTH COULD ALSO SUPPORT ISOLD
TSRA.
SATURDAY...SOME SHOWERS MAY LINGER OVER THE SE PORTION OF THE CWA
ASSOCIATED WITH REMNANTS OF THE WI SHRTWV OR POSSIBLY AIDED BY A
TRAILING SHRTWV DIVING INTO NRN WI. HOWEVER...EXPECT THE PCPN TO
SLIDE OFF TO THE EAST BY AFTERNOON. WITH SOME CLEARING INTO THE WEST
HALF BY AFTERNOON...TEMPS WILL REBOUND INTO THE MID AND UPPER 70S.
GREATER CLOUD COVER OVER THE EAST AND WITH SRLY FLOW OFF OF LAKE
MI...TEMPS WILL REMAIN IN UPPER 60S AND LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM EDT FRI AUG 28 2015
COULD SEE A FEW SHOWERS IN THE FIRST 6 HOURS OF THE FORECAST SAT
NIGHT...BUT THINK VAST MAJORITY OF PRECIP ASSOCIATED WITH A
SHORTWAVE WILL BE OUT OF THE AREA. OTHERWISE...PRECIP CHANCES ARE
LOW IN THE LONG TERM AS A MID-UPPER RIDGE MOVES IN AND SITS OVER THE
CENTRAL TO ERN CONUS. COULD SEE SOME PRECIP MID-LATE NEXT WEEK AS
SHORTWAVES TRY TO TOP THE RIDGE...BUT PREDICTABILITY IS TOO LOW TO
JUSTIFY ANYTHING ABOVE SLIGHT CHANCE POPS.
TEMPS WILL BE ON THE INCREASE AND WILL ALREADY BE ABOVE NORMAL SUN.
HIGHS SUN WILL BE IN THE MID 70S TO LOW 80S AS 850MB TEMPS START OUT
IN THE MID TEENS C. 850MB TEMPS THROUGH THE REST OF THE WEEK WILL BE
AROUND 20C...RESULTING IN HIGH TEMPS 10 OR MORE DEGREES ABOVE
NORMAL.
COULD SEE SOME PATCHY FOG AROUND SAT NIGHT INTO EARLY SUN MORNING
AND AGAIN SUN NIGHT INTO MON MORNING AS HIGH PRESSURE/SUBSIDENCE
MOVES IN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 128 AM EDT SAT AUG 29 2015
VFR CONDITIONS WILL CONTINUE THROUGH THIS FCST PERIOD AT ALL SITES.
POSSIBLE ISOLD TSRA COULD AFFECT KCMX TERMINAL EARLY THIS MORNING AS
CLUSTERS OF TSRA OVER WESTERN LK SUPERIOR SLIDE TOWARD KEWEENAW
PENINSULA WHILE WEAKENING. WILL MONITOR AND UPDATE AS NECESSARY. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT FRI AUG 28 2015
EXPECT A PERIOD OF MODERATE SW WINDS LATE TONIGHT INTO EARLY SATURDAY
GUSTING TO 15-20 KNOTS. OTHERWISE...A GENERALLY WEAK PRES GRADIENT
WILL DOMINATE THE UPPER LAKES INTO EARLY NEXT WEEK. ON MOST
DAYS...WINDS WILL BE UNDER 15KT. LOOKS LIKE THE LIGHTEST WINDS WILL
OCCUR OVER THE WEEKEND WITH HIGH PRES RIDGE MORE FIRMLY IN CONTROL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLA
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1216 AM CDT SAT AUG 29 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 315 PM CDT FRI AUG 28 2015
WATER VAPOR IMAGERY SHOWS THAT A SHORTWAVE TROUGH IS MOVING SLOWLY
EAST ACROSS MISSOURI AT THIS HOUR. LATEST RUNS OF THE RAP SUGGEST
THAT IT WILL TAKE ALL EVENING FOR THIS FIRST SHORTWAVE TO REACH
HALFWAY ACROSS THE CWA WHILE A SECOND SHORTWAVE WILL ENTER WESTERN
MISSOURI BEHIND IT LATER TONIGHT. LOW LEVEL MOISTURE CONVERGENCE
WILL INCREASE ACROSS EASTERN MISSOURI BY LATER THIS EVENING AS LOW
LEVEL JET VEERS AND INCREASES IN SPEED SLIGHTLY. THIS SHOULD CAUSE
AN INCREASE IN COVERAGE IN SCATTERED SHOWERS AND THUNDERSTORMS BY
LATE EVENING AND OVERNIGHT OVER THE REGION BECAUSE OF THE FORCING
FROM THE SHORTWAVES AND THE MOISTURE CONVERGENCE. THE 1KM
REFLECTIVITY FROM THE CAMS DEPICTS THIS PRETTY WELL.
MOS LOWS TONIGHT LOOK REASONABLE GIVEN THE INCREASING DEWPOINTS
AHEAD OF THE COLD FRONT CURRENTLY OVER THE CENTRAL PLAINS.
BRITT
.LONG TERM: (SATURDAY THROUGH NEXT FRIDAY)
ISSUED AT 316 PM CDT FRI AUG 28 2015
AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ON
SATURDAY AND SATURDAY EVENING AS AN UPPER LEVEL TROUGH MOVES
SLOWLY SOUTHEASTWARD THROUGH OUR AREA. IT NOW APPEARS THAT THE
COLD FRONT WILL ONLY MAKE IT INTO NORTHEAST MO AND WEST CENTRAL IL
BEFORE GRADUALLY DISSIPATING. ONLY SLIGHT COOLING IS EXPECTED
ACROSS NORTHEAST MO AND WEST CENTRAL IL SATURDAY AND SATURDAY
NIGHT WITH THE REST OF THE AREA SLIGHTLY WARMER AND MORE HUMID
DESPITE THE CLOUD COVER ON SATURDAY WITH MAINLY A WEAK SOUTHERLY
FLOW. ALTHOUGH THE CHANCE OF PRECIPITATION WILL LESSEN BY LATE
SATURDAY NIGHT AND SUNDAY...THERE MAY STILL BE AT LEAST ISOLATED
SHOWERS/STORMS ACROSS MAINLY SOUTHEAST MO AND SOUTHWEST IL AS THE
WEAKENING UPPER LEVEL TROUGH...SHEAR AXIS MOVES ONLY SLOWLY
SOUTHEASTWARD. A WAMER PERIOD OF WEATHER IS FORECAST FOR THE NEXT
WORK WEEK DUE TO PERSISTENT SOUTHERLY SURFACE/LOW LEVEL FLOW WITH
THE SURFACE/850 MB RIDGE EAST/SOUTHEAST OF OUR AREA...AND AT
LEAST UPPER LEVEL RIDGING ACROSS NORTHWEST MO. WILL KEEP THE
REMAINDER OF THE FORECAST DRY FOR NOW...ALTHOUGH COULD NOT RULE
OUT A FEW SHOWERS/STORMS MAINLY DURING THE AFTERNOON AND EARLY
EVENING HOURS AS THE MODELS CONTINUE TO DEPICT SOME WEAK MID-UPPER
LEVEL TROUGHING...SHEAR AXIS ACROSS MAINLY SOUTHEAST MO AND
SOUTHWEST IL.
GKS
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1208 AM CDT SAT AUG 29 2015
SPECIFICS FOR KCOU, KUIN: RAIN SHOWERS WILL CONTINUE TO INCREASE
IN COVERAGE OVERNIGHT AS A COUPLE OF UPPER LEVEL DISTURBANCES
APPROACH THE REGION. THUNDERSTORMS ARE POSSIBLE AT KUIN DURING THE
AFTERNOON, BUT CURRENT MODELS SUGGEST THE PRECIPITATION WOULD BE
EAST OF KCOU BY THEN. WINDS WILL REMAIN SOUTHEASTERLY TO
SOUTHERLY, THEN BECOME LGT/VAR INVOF A WEAK COLD FRONT.
SPECIFICS FOR KSTL, KSUS, KCPS: THE INCOMING SHIFT NOTICED SOME
LIGHT RAIN ON THEIR COMMUTE TO THE OFFICE IN WELDON SPRING, SO IT
LOOKS LIKE AT LEAST SOME OF THOSE WEAKER ECHOES ON RADAR ARE
PRODUCING RAINFALL. ADDED VCSH TO KSUS AND KSTL FOR THE NEXT FEW
HOURS BASED ON THE CURRENT RADAR TRENDS. SHOWERS SHOULD BECOME
MORE WIDESPREAD WITH TIME AS A COUPLE OF UPPER LEVEL DISTURBANCES
MOVE ACROSS THE AREA. THUNDERSTORMS ARE POSSIBLE DURING THE
AFTERNOON. WINDS WILL REMAIN SOUTHEASTERLY TO SOUTHERLY, THEN
BECOME LGT/VAR INVOF A WEAK COLD FRONT.
KANOFSKY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1149 PM CDT FRI AUG 28 2015
.DISCUSSION...
Issued at 409 PM CDT FRI AUG 28 2015
Tonight...
Positive tilted shortwave trough as noted in satellite imagery from
IA through KS will slide east tonight. Scattered convection will
form along an associated cold front within a moderately
unstable airmass....at least it will be into the early evening
hours.
A narrow band of convection has finally formed over east
central KS where MLCAPES between 1500-2000J/kg are noted. Further
northeast VFR ceilings within the warm sector have pretty much
capped intense convection as radar shows sputtering area of low
topped showers. The east central KS activity may be the only region
which develops deep convection, albeit the non-severe variety. Will
hit PoPs highest over northern and west central counties until a few
hours after sunset. Thereafter expect a fairly quick drop off in
intensity and coverage as instability hits the skids. Believe the
trend of the HRRR and 12z NAM looks reasonable. QPF will also be
muted. Could see isolated showers form after the passage of the
frontal convection and last into the pre-dawn hours.
Saturday - Sunday...
The above shortwave is expected to flounder over the Mid MO Valley
over the weekend. The h7 shortwave trough will be slow to exit the
CWA resulting in a general region of uvv over the eastern 1/2 of the
CWA. Thinking there will be sufficient breaks in the overcast such
that isolated instability showers/storms will be possible Saturday
afternoon over parts of northeast and central MO. Current
temperature forecast may be a bit too optimistic should the
afternoon clouds fail to break up.
Sunday looks dry with a slight warm-up as the mid level trough
washes out.
Monday - Friday...
The operational models transition to a broadening southwesterly flow
pattern after the upper level ridge axis leans over into the Central
Plains. This will allow warmer more seasonal temperatures and
humidity back into the region. While the h7 temperatures don`t get
overly hot and cap off the environment a lack of any discernible
mid/upper level wave or surface boundaries will greatly limit the
rain chances. As such will go with a dry forecast until some feature
of significance is picked up by the models.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1149 PM CDT FRI AUG 28 2015
Cold front currently moving through the region which will lead to a
gradual wind shift to the northwest late this evening/early Saturday
morning. Satellite imagery this evening showing plenty of low status
across eastern Nebraska and western Iowa...which fcst models show
gradually shifting south across area terminals after 8z or so. As
such...have elected to highlight IFR probabilities at all sites with
the exception of IXD which may be too far south. Look for minor
improvements in the morning with MVFR cigs likely sticking around
through early to mid-afternoon.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...32
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
341 AM MDT SAT AUG 29 2015
.SYNOPSIS...
STORM COVERAGE WILL LOWER SLIGHTLY TODAY ALTHOUGH LOCALLY HEAVY
RAIN WILL REMAIN POSSIBLE OVER THE MOUNTAINS...ESPECIALLY
SOUTHWEST AND NORTHERN SACRAMENTOS. THE FAVORED STORM COVERAGE
AREAS WILL SHIFT WESTWARD AND FAVOR THE CONTINENTAL DIVIDE TO THE
ARIZONA BORDER ON SUNDAY. A PACIFIC TROUGH WILL NUDGE CLOSER TO
THE STATE ON MONDAY AND SHIFT THE MAIN STORM COVERAGE FURTHER
EAST. LOCALLY HEAVY RAIN WILL REMAIN POSSIBLE SUNDAY/MONDAY. THE
MONSOON MOISTURE PLUME...ALBEIT DISJOINTED AT TIMES... WILL REMAIN
OVER PORTIONS OF THE STATE THROUGH THE REST OF THE WEEK. A MORE
CONCENTRATED MOISTURE PLUME WILL BE POSSIBLE NEXT WEEKEND AS A
PACIFIC TROUGH STRENGTHENS AND DEEPENS TO THE WEST OF THE STATE.
&&
.DISCUSSION...
MASSAGED POPS/SKY COVER AND WEATHER HERE AND THERE BUT NO MAJOR
CHANGES. THE OVERALL WEATHER THEME APPEARS TO BE SIMILAR. A LITTLE
LESS STORM COVERAGE WITH THE FOCUS GRADUALLY SHIFTING WESTWARD
TODAY. THE MAIN FOCUS ON SUNDAY STILL APPEARS TO BE ACROSS THE
WESTERN THIRD AND CURRENT POPS REFLECT THAT. THE PACIFIC TROUGH
WILL NUDGE CLOSER TO THE STATE ON MONDAY THUS SHIFTING THE MAIN
MOISTURE PLUME A LITTLE FURTHER EAST. IT APPEARS THAT THE PAC
TROUGH WOULD REFORM OR DEEPEN TO THE WEST TUESDAY AND CONTINUE
INTO NEXT WEEKEND. THIS WOULD PLACE THE MAIN MONSOONAL MOISTURE
PLUME OVER SOME PORTION OF THE STATE DURING THIS PERIOD. THUS AN
ACTIVE PERIOD BUT NOTHING OUT OF THE ORDINARY AT THIS TIME. WILL
BE FOLLOWING THE UPPER HIGH PROGRESSION BECAUSE ONCE IT
CONSOLIDATES/LESS HIGH CENTERS/ AND MOVES EAST OF THE STATE THEN A
JUICIER MOISTURE FLOW SHOULD ENSUE. THAT APPEARS POSSIBLE LATE
WEEKEND OR DURING NEXT WEEKEND.
SOME MODEL DISPCREPANCIES FOR TODAYS POP FORECAST. HRRR IS MUCH
MORE BULLISH ACROSS THE EASTERN PLAINS COMPARED TO THE NAM/GFS.
LATEST WATER VAPOR IMAGERY SHOWS A DRIER AND MORE STABLE AIRMASS
POISED TO THE NORTH OF THE STATE SO WOULD EXPECT SOME OF THIS AIR
TO MAKE IT INTO EASTERN NM AS THE DAY PROGRESSES. DESPITE THIS
IMPACT...DECIDED TO BEEF UP POPS A BIT MORE ACROSS THE EC/SE
PLAINS THANKS TO THE LATEST HRRR FORECAST. EITHER WAY...MAIN FOCUS
WILL BE SHIFTING SLIGHTLY MORE TO THE WEST. STEERING FLOW FOR THE
STORMS APPEARS TO BE PRETTY LIGHT DUE TO THE CLOSE PROXIMITY TO
THE HIGH CENTER. ONE NOTABLE STEERING FLOW DIRECTION WOULD BE THE
NE FLOW ORIGINATING FROM THE SANDIA MTNS. THIS FLOW USUALLY BODES
WELL FOR PORTIONS OF THE ABQ NE HEIGHTS SO FOOTHILL RECREATIONALISTS
SHOULD BE COGNIZANT OF THAT POTENTIAL IMPACT. ALSO BEEFED UP QPF
AND POPS ACROSS THE GILA REGION AND NORTHERN SACRAMENTO MTNS.
SINCE THE CELLS SHOULD TRAVEL SOUTHWARD OVER THE SACS...RESIDENCE
TIME MAY NOT BE ALL THAT MUCH...BUT SOMETHING TO WATCH IN TERMS
OF LOCALIZED FLOODING. LOCALIZED FLOODING ALSO POSSIBLE ACROSS
THE GILA REGION. BASED ON THE LATEST NASASPORT SOIL MOISTURE
IMAGERY...CATRON COUNTY APPEARS TO BE RATHER MOIST AS WELL AS
PORTIONS OF THE CENTRAL MTNS/EAST SLOPES.
NOT A LOT OF SIGNIFICANT CHANGES IN THE LATEST MODELING. THE
INITIAL PAC TROUGH IS EXPECTED TO SHEAR OUT ACROSS THE
NORTHERN/CENTRAL ROCKIES/NORTHERN PLAINS SUNDAY/MONDAY. LOCALLY
HEAVY RAIN AND A DIFFUSE MONSOONAL MOISTURE PLUME WILL FAVOR THE
CONTINENTAL DIVIDE WESTWARD SUNDAY. THEN SHIFT A BIT MORE TO THE
EAST ON MONDAY BASED ON THE INITIAL PAC TROUGH EJECTION.
THE PAC TROUGH WILL DEEPEN TO THE WEST OF THE STATE TUESDAY
THROUGH THE END OF THE WEEK. PRETTY TYPICAL PATTERN FOR
SEPTEMBER...AT LEAST BASED ON THE PAST FEW YEARS. MONSOONAL
MOISTURE WILL TRY TO MOVE NORTHWARD AHEAD OF THE TROUGH AND
CONTINUE SH/TS OVER THE FORECAST AREA. SUBTLE DAY TO DAY CHANGES
WILL DEPEND ON WEAK VORTICE WAVES ORIGINATING FROM MEXICO AS WELL
AS A DRIER AND MORE STABLE AIRMASS ROTATING AROUND THE HIGH
CENTER. IT APPEARS THAT BASED ON THE PAC TROUGH PROGRESSION...THE
UPPER HIGH WOULD EVENTUALLY SHIFT EAST OF THE STATE ALTHOUGH THIS
PROGRESSION WILL MOST LIKELY JUMP AROUND A BIT BECAUSE THE MODELS
HAVE BEEN HAVING A HARDER TIME WITH THE PROGRESSION OF THE PAC
TROUGH ALONG THE WEST COAST. EITHER WAY...WOULD EXPECT THE
MONSOONAL MOISTURE PLUME...ORIGINATING FROM MEXICO...TO BECOME
MORE CONSOLIDATED AROUND THE UPPER HIGH OR BECOMING LESS DIFFUSE.
WILL JUST HAVE TO WAIT ON SEE ON THAT ONE. DECIDED TO INCREASE
TEMPS SLIGHTLY ABOVE MODEL GUIDANCE OR SUPER BLEND LEVELS DURING
THE EXTENDED PERIOD. ALSO LOWERED MIN TEMPS IN THE HIGHER MTN
BASINS SUCH AS THE MORENO VALLEY DUE TO LOWERING DEWPOINTS.
50
&&
.FIRE WEATHER...
BACK DOOR FRONT HAS PUSHED WESTWARD TO THE CONTDVD EARLY THIS
MORNING. THIS WILL SET THE STAGE FOR MORE ACTIVITY ACROSS WESTERN NM
TODAY AS COMPARED TO YESTERDAY...THOUGH WETTING RAINS WILL STILL BE
SPOTTY...WITH THE WEST CENTRAL HIGHLANDS BEING THE EXCEPTION. HI-RES
MODELS STILL SHOWING A FAIR AMOUNT OF ACTIVITY ACROSS THE EASTERN
PLAINS AS WELL...BUT WITH DRIER AIR MOVING IN...IT SHOULD NOT BE AS
WIDESPREAD OR AS ORGANIZED AS YESTERDAY. STORM MOTION LOOKS TO SHIFT
A BIT TODAY...PERHAPS MORE TOWARD THE SOUTHWEST OR WEST ACROSS THE
EAST AND MORE TOWARD THE NORTH ACROSS THE WEST.
THE UPPER HIGH IS STILL ON TRACK TO ELONGATE FROM SW TO NE FROM SE
AZ TO NE NM ON SUNDAY. MEANWHILE...THE CENTROID OF THE MID LEVEL
HIGH WILL SHIFT OVER EASTERN NM OR WEST TEXAS. THIS WILL ALLOW MID
LEVEL MOISTURE TO STREAM NORTHWARD ACROSS FAR WESTERN NM AND EASTERN
AZ. APPEARS THAT THE BEST PRECIP CHANCES WILL BE ACROSS THE WESTERN
THIRD OF THE STATE AND SOME SPOTTY HEAVY RAINFALL WILL BE POSSIBLE.
STORM MOTION WILL GENERALLY BE TOWARD THE NORTHEAST AROUND 5-10 MPH.
THE MOISTURE PLUME STILL LOOKS TO SHIFT EASTWARD ON MONDAY...
FOCUSING THE BEST CHANCE FOR TSTMS FROM THE WEST CENTRAL HIGHLANDS
NEWD TO THE NE PLAINS. STORM MOTION WILL LIKELY BE A BIT MORE
ERRATIC...BUT GENERALLY FROM WEST TO EAST OR SW TO NE.
APPEARS THAT THE MOISTURE PLUME WILL STILL BE HOVERING OVER NM ON
TUESDAY...THOUGH NOT AS ROBUST AS SUNDAY OR MONDAY. WILL STILL LOOK
FOR STORMS...MAINLY OVER THE HIGH TERRAIN.
ECMWF AND CANADIAN MODELS CONTINUE TO SHOW THE UPPER HIGH CENTERED
FARTHER SOUTH WEDNESDAY...ALLOWING FOR DRIER WESTERLY FLOW ACROSS
NORTHERN NM. THE GFS HANGS ONTO A DISORGANIZED PLUME ON WEDNESDAY
WITH THE HIGH OVER WEST TEXAS...THOUGH BY THURSDAY...THE HIGH
WEAKENS ALLOWING THAT DRIER AIR INTO NORTHERN NM. WITH MODEL
INCONSISTENCIES OF LATE...HARD TO HAVE A DEFINITE ANSWER...BUT IT
DOES LOOK LIKE MODELS ARE TRENDING TOWARD A DRIER LATTER HALF OF
NEXT WEEK.
VERY LITTLE TEMPERATURE CHANGES OVER THE NEXT SEVERAL DAYS... WITH
HIGHS GENERALLY AT OR ABOVE NORMAL. HUMIDITIES WILL LOWER WED/THURS
MAINLY ACROSS NORTHERN NM IF THE AFOREMENTIONED PATTERN COMES TO
FRUITION. WEAK TRANSPORT WINDS WILL CONTINUE TO RESULT IN POOR TO
FAIR VENT RATES ACROSS NORTH CENTRAL NM TODAY...BUT SHOULD GENERALLY
IMPROVE INTO THE GOOD TO EXCELLENT RANGE NEXT WEEK. ONE EXCEPTION
MAY BE ACROSS THE SANGRE DE CRISTO MOUNTAINS ON MONDAY.
34
&&
.AVIATION...
06Z TAF CYCLE
CONVECTION IS EXPECTED TO CONTINUE TO DIMINISH
THROUGH THE LATE NIGHT HOURS. A BACK DOOR COLD FRONT WILL FINISH
PUSHING THROUGH W AREAS TONIGHT INCREASING HUMIDITIES THERE FOR
SATURDAY. TS WILL FAVOR THE CONTDVD AND CENTRAL MT CHAIN SATURDAY.
MODELS ARE COMING INTO BETTER AGREEMENT ON A N TO S MOVEMENT OF
STORMS ON SATURDAY...WHICH MATCHES WHAT GENERALLY OCCURRED TODAY.
AIRPORTS NEAR MTS HAVE THE BEST CHANCE OF GETTING HIT BY TS/SHRA
SATURDAY AFTN AND EVENING...ESPECIALLY KSAF. &&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 90 61 88 59 / 5 10 20 40
DULCE........................... 83 50 84 50 / 30 10 10 50
CUBA............................ 82 52 83 52 / 40 20 30 30
GALLUP.......................... 86 54 84 53 / 20 20 60 50
EL MORRO........................ 82 52 80 51 / 20 40 40 40
GRANTS.......................... 83 53 82 53 / 20 50 40 50
QUEMADO......................... 83 53 81 55 / 20 40 30 50
GLENWOOD........................ 87 59 84 60 / 40 30 40 50
CHAMA........................... 76 48 77 48 / 50 20 10 40
LOS ALAMOS...................... 81 57 82 57 / 30 20 40 30
PECOS........................... 79 53 81 55 / 50 20 20 10
CERRO/QUESTA.................... 79 49 81 50 / 40 20 10 10
RED RIVER....................... 68 41 71 43 / 50 20 20 10
ANGEL FIRE...................... 72 43 75 45 / 50 20 10 10
TAOS............................ 81 49 82 51 / 10 10 5 10
MORA............................ 75 50 80 53 / 50 20 20 10
ESPANOLA........................ 86 54 87 55 / 20 10 10 20
SANTA FE........................ 82 56 83 57 / 40 20 5 10
SANTA FE AIRPORT................ 85 57 86 58 / 20 20 5 10
ALBUQUERQUE FOOTHILLS........... 87 62 88 63 / 50 30 5 10
ALBUQUERQUE HEIGHTS............. 87 65 88 66 / 20 20 5 10
ALBUQUERQUE VALLEY.............. 89 62 90 63 / 10 20 5 10
ALBUQUERQUE WEST MESA........... 88 63 89 64 / 10 20 5 10
LOS LUNAS....................... 90 61 91 62 / 10 20 5 10
RIO RANCHO...................... 87 61 89 63 / 10 20 5 10
SOCORRO......................... 89 61 89 63 / 10 20 5 20
SANDIA PARK/CEDAR CREST......... 83 59 84 59 / 50 30 20 20
TIJERAS......................... 85 58 86 59 / 50 20 10 20
MORIARTY/ESTANCIA............... 83 53 85 54 / 20 10 5 10
CLINES CORNERS.................. 81 55 82 57 / 20 10 5 5
GRAN QUIVIRA.................... 83 57 84 59 / 20 20 5 10
CARRIZOZO....................... 85 59 85 61 / 30 10 5 10
RUIDOSO......................... 76 55 78 58 / 50 20 5 10
CAPULIN......................... 82 53 86 56 / 10 5 0 0
RATON........................... 85 52 88 55 / 10 5 0 10
SPRINGER........................ 85 54 88 56 / 10 5 0 10
LAS VEGAS....................... 80 52 83 55 / 20 10 5 5
CLAYTON......................... 87 60 91 62 / 5 5 0 5
ROY............................. 85 56 88 58 / 10 5 0 5
CONCHAS......................... 91 63 93 64 / 10 5 0 5
SANTA ROSA...................... 89 60 91 63 / 10 5 0 5
TUCUMCARI....................... 92 62 94 65 / 10 5 0 0
CLOVIS.......................... 89 61 91 63 / 20 5 0 0
PORTALES........................ 90 60 92 64 / 20 10 0 0
FORT SUMNER..................... 91 63 92 63 / 10 5 0 5
ROSWELL......................... 92 65 95 65 / 20 10 0 5
PICACHO......................... 86 59 88 61 / 20 10 0 10
ELK............................. 81 57 82 58 / 40 20 0 10
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
50
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1237 AM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 1237 AM CDT SAT AUG 29 2015
VISIBILITIES WERE AROUND 3-6 MILES IN SMOKE OVER PARTS OF WESTERN
AND CENTRAL NORTH DAKOTA. EXPECTING FOG FORMATION AS WELL OVER MUCH
OF CENTRAL NORTH DAKOTA...WITH RELATIVELY HUMID AIR WITH DEWPOINTS
IN THE 60S. FARTHER WEST DEWPOINTS WERE IN THE 40S AND 50S WITH THE
INFLUENCE OF THE DRIER WESTERN US RIDGE AIRMASS. EXPECT VISIBILITIES
REDUCED FOR THE EARLY MORNING HOURS UNTIL AFTER AROUND 8 TO 10 AM
CDT WHEN SOME SOUTHERLY/SOUTHWESTERLY WINDS BEGIN TO INCREASE.
OTHERWISE MADE SOME MINIMUM TEMPERATURE ADJUSTMENTS...WITH HETTINGER
ALREADY DIPPING TO 54 DEGREES. MAIN ELEMENTS OF THE FORECAST REMAIN
ON TRACK.
UPDATE ISSUED AT 845 PM CDT FRI AUG 28 2015
ADDED A MENTION OF FOG FOR TONIGHT INTO SATURDAY MORNING FOR
LOCATIONS GENERALLY ALONG AND EAST OF US HIGHWAY 83...WHERE MID
TO UPPER 60S F DEWPOINTS WERE OBSERVED AS OF 01 UTC. THE 23-00 UTC
RAP ITERATIONS HOLD THIS MOISTURE IN THROUGH THE NIGHT...SUPPORTED
BY THE HRRR VISIBILITY PRODUCT RAPIDLY DECREASING LATE TONIGHT
INTO SATURDAY MORNING FOR THE AFOREMENTIONED AREAS.
UPDATE ISSUED AT 633 PM CDT FRI AUG 28 2015
DID ADD AREAS OF SMOKE TO THE FORECAST FOR THE REMAINDER OF THE
EVENING INTO SATURDAY GIVEN SATELLITE AND SURFACE OBSERVATION
TRENDS THROUGH 23 UTC. OTHERWISE...THE FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 345 PM CDT FRI AUG 28 2015
MAIN CONCERN IN THE SHORT TERM WILL BE FIRE WEATHER POTENTIAL OVER
WESTERN NORTH DAKOTA FOR SATURDAY. AFTER A QUIET NIGHT TONIGHT A
VERY WARM AIRMASS WILL ALLOW TEMPERATURES TO RISE INTO THE 90S TO
NEAR 100 ACROSS WESTERN NORTH DAKOTA SATURDAY. MINIMUM RELATIVE
HUMIDITY COULD FALL AS LOW AS 15 PERCENT. A FIRE WEATHER WATCH HAS
BEEN ISSUED FOR WESTERN NORTH DAKOTA...WEST OF THE MISSOURI RIVER
UP TO LAKE SAKAKAWEA AND GENERALLY WEST OF HIGHWAY 83 NORTH OF
LAKE SAKAKAWEA.
OTHERWISE...A WEAK TROUGH OF LOW PRESSURE WAS THE FOCUS FOR A FEW
THUNDERSTORMS FRIDAY MORNING AND EARLY AFTERNOON ACROSS NORTHEAST
ND. AS THIS TROUGH SLIDES SOUTHEAST THIS AFTERNOON AND EVENING AN
ISOLATED THUNDERSTORM MAY YET BE POSSIBLE ACROSS THE JAMES RIVER
VALLEY INTO THIS EVENING. OTHERWISE WILL KEEP A MENTION OF SMOKE
IN TONIGHT MOST OF WEST AND CENTRAL NORTH DAKOTA. THE SMOKE HAS
BEEN MAINLY ALOFT BUT SKIES ARE QUITE COVERED WITH IT AND THERE
CONTINUES TO BE A SCENT OF IT AT THE SURFACE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 PM CDT FRI AUG 28 2015
WARM TEMPERATURES AND PERIODIC THUNDERSTORM CHANCES WILL HIGHLIGHT
THE EXTENDED FORECAST PERIOD NEXT WEEK.
WESTERN CONUS UPPER LEVEL RIDGE WILL AMPLIFY INTO THE CENTRAL U.S
OVER THE UPCOMING WEEKEND...THEN TRANSLATE TO THE EASTERN CONUS NEXT
WEEK PUTTING SOUTHWEST FLOW ALOFT INTO THE NORTHERN PLAINS THROUGH
THE WORK WEEK. THE UPPER RIDGE THIS WEEKEND WILL BRING WELL ABOVE
NORMAL TEMPERATURES AND LIMITED PRECIPITATION CHANCES TO WESTERN
AND CENTRAL NORTH DAKOTA THROUGH SUNDAY DAYTIME.
ON SUNDAY WE ARE EXPECTING SLIGHTLY COOLER TEMPERATURES IN THE
NORTHWEST. THE THERMAL RIDGE SHIFTS INTO CENTRAL NORTH
DAKOTA...THUS MINOT AND BISMARCK COULD SEE TEMPERATURES
APPROACHING RECORDS ONCE AGAIN FOR SUNDAY...BUT MUCH WILL DEPEND
ON THE TIMING OF AN APPROACHING COLD FRONT.
ISOLATED THUNDERSTORMS WILL ENTER THE FORECAST SUNDAY NIGHT WITH
ENERGY ALOFT AND THE AFOREMENTIONED COLD FRONT/SFC BOUNDARY
MOVING SLOWLY SOUTH AND EAST THROUGH NORTH DAKOTA...COOLING
TEMPERATURES BACK DOWN INTO THE 80S FOR MONDAY.
BROAD SOUTHWEST UPPER LEVEL FLOW WILL THEN PERSIST THROUGH NEXT
WEEK. NO MAJOR SYSTEMS DEPICTED...BUT WE CAN EXPECT DAILY ISOLATED
TO SCATTERED THUNDERSTORM CHANCES WITH ANY EMBEDDED SHORTWAVE
WHICH TRAVELS THROUGH THE FLOW ALOFT COUPLED WITH ANY ASSOCIATED
BOUNDARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1237 AM CDT SAT AUG 29 2015
MVFR VISIBILITY IN SMOKE FROM NORTHWEST U.S. FIRES ARE POSSIBLE
AT KDIK/KISN/KBIS/KMOT THIS MORNING. SMOKE MAY BE DENSE ENOUGH TO
DROP VISIBILITY TO IFR AT KDIK AND KISN TONIGHT. PATCHY FOG IS
POSSIBLE IN THE KJMS/KBIS VICINITY THIS MORNING. ADDED MENTION OF
SCT-BKN CIGS AT 3000-5000 FEET AS SENSORS DETECTING A CIG WITH SMOKE
PARTICLES. AFTER 16Z SOUTH TO SOUTHWEST WINDS SHOULD INCREASE AND
DISSIPATE FOG AND SURFACE SMOKE. VFR CONDITIONS EXPECTED AFTER VSBY
REDUCTIONS END BY AROUND 16Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM 11 AM CDT /10 AM MDT/ THIS MORNING
THROUGH THIS EVENING FOR NDZ001-002-009>011-017>021-031>034-
040>045.
&&
$$
UPDATE...JV
SHORT TERM...WAA
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS PENDLETON OR
300 AM PDT SAT AUG 29 2015
.SHORT TERM...TODAY THROUGH MONDAY...POTENT UPPER LEVEL TROUGH OFF
THE OREGON COAST WILL LIFT NEWD INTO NW WASHINGTON AND DEAMPLIFY AS
IT MOVES INTO BRITISH COLUMBIA TODAY AND TONIGHT. THE MAIN IMPACT
FROM THIS SYSTEM WILL BE SOME RAIN ALONG THE CASCADES AND GUSTY SW
WINDS FROM MID MORNING UNTIL LATE THIS AFTERNOON. WIND ADVISORIES
ARE IN EFFECT FOR MUCH OF THE LOWER ELEVATIONS. WITH LITTLE RAIN
EXPECTED EAST OF THE CASCADES EXPECT SOME BLOWING DUST AS WELL.
BLOWING DUST ADVISORIES ARE IN EFFECT FOR THE BLUE MOUNTAIN
FOOTHILLS...YAKIMA VALLEY AND COLUMBIA BASIN. LOOKING AT THE PAST
FEW RUNS OF THE HRRR IT APPEARS THAT THE STRONGEST WIND TODAY WILL
BE OVER THE YAKIMA VALLEY AND SIMCOE HIGHLANDS WITH GUST POTENTIAL
REACHING 50 TO 55 MPH LATE THIS MORNING INTO EARLY THIS AFTERNOON.
THIS MAKES SENSE BECAUSE THIS AREA IS CLOSER TO THE TRACK OF THE
UPPER TROUGH. WINDS WILL DECREASE QUICKLY BY EARLY EVENING. AS A
SECOND UPPER TROUGH APPROACHES LATER TONIGHT RAIN IS EXPECTED TO
SPREAD EAST OF THE CASCADES. THIS RAIN WILL MOVE ACROSS THE ENTIRE
FORECAST AREA ON SUNDAY. BUMPED UP POPS QUITE A BIT FOR SUNDAY TO
REFLECT THE MODELS WETTER TRENDING...AND POPS MAY NEED TO BE RAISED
FURTHER. THERE IS A CHANCE FOR QUARTER INCH AMOUNTS WITH THIS SYSTEM
OVER A WIDE AREA WHICH WOULD REALLY HELP WITH THE ONGOING FIRES. BY
MONDAY THE TROUGH WILL HAVE MOVED EAST OF THE REGION WITH GENERALLY
DRY CONDITIONS AND COOL TEMPERATURES. 78
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY..THE AREA WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH THROUGH THE LONG TERM PERIOD
AND UNSETTLED WEATHER IS EXPECTED. ON MONDAY NIGHT THE TROUGH WILL
BE BROAD AND SHALLOW WITH A WESTERLY FLOW OVER THE AREA. AN UPPER
LOW WILL BE OFF THE NORTHERN BRITISH COLUMBIA COAST AND WILL SINK
SOUTH, ENDING UP NEAR NORTHERN VANCOUVER ISLAND BY TUESDAY
AFTERNOON. RAIN SHOWERS WILL STRUGGLE TO GET VERY FAR PAST THE
CASCADE CREST THOUGH BY TUESDAY AFTERNOON, THERE SHOULD BE A FEW
LIGHT SHOWERS AS FAR EAST AS YAKIMA AND ELLENSBURG. THE REST OF THE
AREA WILL REMAIN DRY. WINDS WILL BECOME BREEZY TUESDAY AFTERNOON.
THE UPPER LOW WILL DEEPEN THE TROUGH AND TURN THE FLOW OVER OUR AREA
MORE SOUTHWESTERLY. A FRONT WILL MOVE THROUGH THE AREA TUESDAY NIGHT
AND WEDNESDAY BRINGING A CHANCE OF LIGHT RAIN TO THE ENTIRE AREA.
ANOTHER IMPULSE WILL MOVE THROUGH THE TROUGH ON THURSDAY AND BRING A
CHANCE OF RAIN AND A SLIGHT CHANCE OF THUNDERSTORMS TO THE MOUNTAINS
WITH A SLIGHT CHANCE OF RAIN IN CENTRAL OREGON AND THE BLUE MOUNTAIN
FOOTHILLS. THE GFS SHOWS THE IMPULSE CARVING THE TROUGH FURTHER
SOUTH ON FRIDAY WITH A SLIGHT CHANCE OF THUNDERSTORMS IN THE EASTERN
MOUNTAINS. THE ECMWF IS LESS VIGOROUS WITH THIS IMPULSE AND DOES NOT
SHOW ANY PRECIPITATION BUT DOES DEEPEN THE TROUGH SOMEWHAT. HAVE
LEANED TOWARDS THE GFS AND PUT A SLIGHT CHANCE OF THUNDERSTORMS IN
THE EASTERN MOUNTAINS. ON SATURDAY, BOTH MODELS SHOW THE TROUGH
STARTING TO MOVE EASTWARD WITH A SLIGHT CHANCE OF THUNDERSTORMS
MAINLY IN WALLOWA COUNTY AND THE HIGHER TERRAIN IN THE REST OF THE
EASTERN MOUNTAINS. TUESDAY WILL SEE TEMPERATURES IN THE 70S AND
LOWER 80S. WEDNESDAY AND THURSDAY WILL BE COOLER WITH HIGHS IN THE
MID 60S TO MID 70S. FRIDAY AND SATURDAY WILL SEE TEMPERATURES BACK
IN THE MID 70S TO LOWER 80S WITH MID 60S TO MID 70S IN THE
MOUNTAINS. PERRY
&&
.AVIATION...PREVIOUS DISCUSSION...06Z TAFS...VFR CONDITIONS WILL
CONTINUE FOR THE NEXT 24 HOURS BUT ARE EXPECTING A FRONTAL PASSAGE
EARLY TO MIDDAY SATURDAY. CEILINGS WILL BE BROKEN TO OVERCAST AT 8K-
12K FEET AGL BUT AGAIN COULD SEE SOME LOWER CEILINGS AROUND FRONTAL
PASSAGE TIME. SMOKE FROM REGIONAL WILDFIRES WILL CONTINUE TO BE
PRESENT ACROSS THE AREA BUT ARE NOT EXPECTED TO LOWER VISIBILITIES
TO MVFR AT ANY TAF SITE. SHOWERS WILL DEVELOP ALONG THE FRONT AND
APPROACH THE CASCADES AFTER 10Z BUT THE PROBABILITY OF RAIN SHOWERS
AT ANY TAF SITE IS FAIRLY LOW DUE TO RAIN SHADOWING. A SIGNIFICANT
WIND INCREASE IS EXPECTED WITH THE FRONTAL PASSAGE ON SATURDAY OF 20-
30 KTS AND HIGHER GUST RESULTING IN BLOWING DUST AND REDUCED SURFACE
VISIBILITIES. 91/93
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 81 54 72 50 / 10 10 50 10
ALW 83 61 73 54 / 10 10 60 10
PSC 83 58 76 56 / 10 10 60 10
YKM 74 53 70 48 / 20 50 40 10
HRI 85 57 74 53 / 10 10 50 10
ELN 74 53 72 50 / 30 50 50 10
RDM 77 48 67 39 / 20 10 50 10
LGD 83 47 69 46 / 20 10 50 10
GCD 82 46 71 36 / 10 10 40 10
DLS 80 61 75 56 / 30 70 70 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 6 PM PDT THIS
EVENING FOR ORZ510-511.
RED FLAG WARNING FROM 7 AM THIS MORNING TO 7 PM PDT THIS EVENING
FOR ORZ640>645.
BLOWING DUST ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS
EVENING FOR ORZ044-507-508.
WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS EVENING
FOR ORZ044-507-508.
WA...RED FLAG WARNING FROM 7 AM THIS MORNING TO 7 PM PDT THIS EVENING
FOR WAZ641-643-645-675.
BLOWING DUST ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS
EVENING FOR WAZ027>029.
WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS EVENING
FOR WAZ027>029-521.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
78/83/83
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
938 PM PDT FRI AUG 28 2015
UPDATED AVIATION AND MARINE DISCUSSIONS.
.SYNOPSIS...AN USUALLY EARLY AND STRONG LOW PRESSURE WILL PRODUCE
WIDESPREAD RAIN AND STRONG WINDS ACROSS NORTHWEST OREGON AND
SOUTHWEST WASHINGTON SATURDAY MORNING. A FEW THUNDERSTORMS EMBEDDED
IN THE RAIN MAY ENHANCE THE WIND THREAT SATURDAY MORNING. A SECOND
FRONT PUSHING INTO THE REGION FROM THE NORTHWEST SATURDAY NIGHT WILL
PRODUCE ANOTHER ROUND OF RAIN. ADDITIONAL SHOWERS WILL FOLLOW ON
SUNDAY. EXPECT COOL WEATHER AND ADDITIONAL ROUNDS OF SHOWERS FOR MUCH
OF THE UPCOMING WORK WEEK.
&&
.SHORT TERM...VISIBLE AND INFRARED SATELLITE IMAGERY SHOW AN
IMPRESSIVE SURFACE LOW PRESSURE UNDERGOING CYCLOGENESIS OFF THE
SOUTHERN OREGON COAST NEAR 130W. BUOY 46002 SLP CONTINUES TO DROP
BETWEEN 2-3MB/HOUR AND OUTPACE THE GFS AND EC FORECASTS CONSIDERABLY.
THE 00Z NAM SEEMS TO HAVE PICKED UP ON THIS ADDITIONAL DEVELOPMENT
AND IS AT LEAST CLOSER TO REALITY THAN THE 18Z GFS AND 12Z EC RUNS AT
THIS POINT. THE NAM FORECASTS THE LOW TO BOTTOM OUT AROUND 990MB OFF
THE MOUTH OF THE COLUMBIA RIVER AROUND 15Z SATURDAY BEFORE CLIPPING
CAPE FLATTERY ON ITS WAY NORTHWARD. SUSPECT IT WILL DROP SOLIDLY INTO
THE 980S. MEANWHILE...THE EC AND GFS HAVE CONTINUED TO TREND TOWARDS
GRADUALLY SHIFTING THE LOW TRACK SLIGHTLY FARTHER OFFSHORE...WHICH
EVEN WITH THE DEEPER DEVELOPMENT OBSERVED SO FAR...SHOULD HELP TO
KEEP THIS STORM FROM REALIZING ITS FULLEST POTENTIAL IN THE
WILLAMETTE VALLEY AND LOWER COLUMBIA RIVER VALLEY. WITH THAT
SAID...THE RAP BRINGS THE LOW PRESSURE ONSHORE OVER THE OLYMPIC
PENINSULA. THE RAP DID A DECENT JOB DEPICTING THE TRACK OF SEVERAL OF
OUR STRONGER LOW PRESSURES LAST YEAR SO IT IS TOUGH TO DISCOUNT IT
EVEN THOUGH IT IS CONSIDERABLY DIFFERENT THAN THE GLOBAL GFS AND EC
MODEL SOLUTIONS. GIVEN THE UNCERTAINTY IN THE FINAL TRACK OF THIS
LOW...ALL THE INHERITED HEADLINES SEEM REASONABLE AT THIS POINT.
HOWEVER...WILL NUDGE UP THE MENTION OF WIND GUSTS ALONG THE NORTH
OREGON AND SOUTH WASHINGTON COASTS AND ACROSS THE LOWER COLUMBIA
RIVER VALLEY AND PORTLAND METRO AREA WHERE A FEW HIGHER WIND GUSTS
SEEM POSSIBLE...ESPECIALLY IF THE LOW PRESSURE PUSHES ONTO THE
WASHINGTON COAST.
EXPECT THE WINDS TO COME ON RATHER SUDDENLY SATURDAY MORNING. THE
STRONG BURST OF WINDS SHOULD FIRST HIT THE CENTRAL OREGON COAST
BETWEEN 4 AM AND 6 AM...AND THE NORTH OREGON COAST...THE SOUTH
WASHINGTON COAST...AND THE WILLAMETTE VALLEY BETWEEN 7 AM AND 10 AM.
WHILE WINDS WILL STILL BE NOTABLY GUSTY SATURDAY AFTERNOON...THE
STRONGEST WINDS WILL LIKELY ONLY LAST FOR 2 TO 4 HOURS.
IN ADDITION...EXPANDED THE MENTION OF THUNDER TO A LARGER PORTION OF
THE CWA FOR SATURDAY MORNING AS THE NAM CONTINUES TO ADVERTISE
SUFFICIENT INSTABILITY TO PRODUCE A THUNDERSTORM OR TWO ALONG THE
FRONT. GIVEN THE AMPLE SHEAR...ANY STORMS THAT DO DEVELOP WILL NEED
TO BE MONITORED CLOSELY FOR PRODUCING LOCALIZED DAMAGING WINDS.
WHILE MOST EVERYONE SHOULD SEE A QUICK SHOT OF RAIN LATER TONIGHT AND
SATURDAY MORNING...SUSPECT TOMORROW WILL BE MORE DRY THAN WET FOR
MANY. HOWEVER...NOT ALL IS LOST AS MODELS HAVE TRENDED WETTER WITH A
SECOND FRONT DROPPING SOUTHEASTWARD OUT OF THE GULF OF ALASKA THAT
WILL PUSH A HEALTHY DOSE OF RAIN ACROSS THE AREA SATURDAY NIGHT.
DECENT ONSHORE FLOW AND INSTABILITY SHOULD LEAD TO MORE SHOWERS AND
POSSIBLY A WET THUNDERSTORM OR TWO SUNDAY.
BELOW AVERAGE TEMPERATURES AND ADDITIONAL ROUNDS OF WET WEATHER
APPEAR LIKELY NEXT WEEK. /NEUMAN
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE FALL-LIKE WEATHER
PATTERN WILL CONTINUE NEXT WEEK WITH PRIMARILY COOLER THAN NORMAL
TEMPERATURES...CLOUDY CONDITIONS...AND CHANCES FOR ADDITIONAL RAIN. A
TROUGH WILL REMAIN NEAR THE PACIFIC NORTHWEST COAST THROUGH MOST OF
THE PERIOD WITH SOME RAIN AT TIMES...ESPECIALLY DURING THE EARLY AND
MIDDLE PARTS OF NEXT WEEK. LITTLE CHANGE MADE TO THE CURRENT
FORECAST. TOLLESON
&&
.AVIATION...VFR CONDITIONS CONTINUE ACROSS THE REGION WITH LIGHT
DRIZZLE STARTING TO MOVE IN ALONG THE COAST. EXPECT CIGS ALONG THE
COAST TO LOWER TOWARDS MVFR OVER THE NEXT SEVERAL HOURS AS RAIN
CHANCES INCREASE. BRIEF PERIODS OF IFR CIGS AND VSBY WILL BE
POSSIBLE UNDER MODERATE TO HEAVY RAIN. RAIN WILL MOVE INLAND AFTER
09Z AND COULD BRING LOWER CIGS AND VSBY TO THE INTERIOR TAF SITES
THROUGH MUCH OF SATURDAY. SOUTHERLY WINDS ALONG THE COAST WILL
INCREASE AROUND 09Z-12Z ALONG THE CENTRAL OREGON COAST AND 12Z
TO 15Z ALONG THE NORTH OREGON COAST...WITH GUSTS UP TO 35 TO 45
KT. SOUTHERLY WINDS AT INLAND SITES START TO INCREASE AROUND 11 TO
13Z WITH GUSTS TO 25 TO 35 KT AND OCCASIONALLY TO 40 KT.
KPDX AND APPROACHES...VFR THROUGH TONIGHT. RAIN CHANCES INCREASE
AFTER 09Z WITH BRIEF PERIODS OF MVFR CIGS AND VSBY POSSIBLE UNDER
MODERATE TO HEAVY RAIN BANDS. SOUTHERLY WINDS INCREASE AROUND 11Z
WITH GUSTS TO 25 TO 35 KT AND OCCASIONAL GUST TO 40 KT POSSIBLE.
/64/MCCOY
&&
.MARINE...A STRENGTHENING FALL-LIKE LOW PRESSURE SYSTEM WILL MOVE
ACROSS THE WATERS SATURDAY. WINDS WILL INCREASE OUT OF THE SOUTH
TO AT LEAST HIGH-END GALES. MODELS HAVE CONTINUED THE UPWARD
TREND IN THE WINDS...WHICH COULD BRING A FEW HOURS OF ISOLATED
STORM FORCE GUSTS LATE SATURDAY MORNING...BUT CONFIDENCE IN THE
DURATION AND EXTENT OF THE STRONGEST WINDS REMAIN TOO LOW TO
UPGRADE TO A STORM WARNING. SEAS CURRENTLY AROUND 4 FT WILL BUILD
RAPIDLY TO 15 TO 17 FT...AND POSSIBLY AS HIGH AS 20 TO 25 FT...AS
THE WINDS INCREASE EARLY SATURDAY MORNING. SEAS WILL REMAIN
ELEVATED THROUGH LATE SATURDAY. WINDS SHIFT MORE TO THE SOUTH-
SOUTHWEST BY SATURDAY EVENING AND FALL BACK DOWN TO 15 KT GUSTING
TO 20 TO 25 KT BY SUNDAY MORNING. SEAS ON SUNDAY WILL BE AROUND 8
TO 10 FT AS WINDS CONTINUE TO DECREASE TO 10 TO 15 KT BY SUNDAY
EVENING.
UNSETTLED WEATHER CONTINUES INTO NEXT WEEK WITH SEAS STAYING
AROUND 7 TO 9 FT THROUGH AT LEAST MIDWEEK. /64/MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 8 AM TO 3 PM PDT SATURDAY FOR GREATER
PORTLAND METRO AREA-LOWER COLUMBIA.
HIGH WIND WARNING FROM 4 AM TO 1 PM PDT SATURDAY FOR CENTRAL
OREGON COAST.
WIND ADVISORY FROM 6 AM TO NOON PDT SATURDAY FOR CENTRAL
WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.
HIGH WIND WARNING FROM 6 AM TO 2 PM PDT SATURDAY FOR COAST
RANGE OF NORTHWEST OREGON-NORTH OREGON COAST.
HIGH WIND WARNING FROM 5 AM TO NOON PDT SATURDAY FOR CENTRAL
COAST RANGE OF WESTERN OREGON.
WA...WIND ADVISORY FROM 8 AM TO 3 PM PDT SATURDAY FOR GREATER
VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ COUNTY.
HIGH WIND WARNING FROM 8 AM TO 3 PM PDT SATURDAY FOR WILLAPA
HILLS.
HIGH WIND WARNING FROM 8 AM TO 2 PM PDT SATURDAY FOR SOUTH
WASHINGTON COAST.
PZ...GALE WARNING FROM 3 AM SATURDAY TO MIDNIGHT PDT SATURDAY
NIGHT FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM
SATURDAY TO MIDNIGHT PDT SATURDAY NIGHT.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
901 PM PDT FRI AUG 28 2015
.SYNOPSIS...AN USUALLY EARLY AND STRONG LOW PRESSURE WILL PRODUCE
WIDESPREAD RAIN AND STRONG WINDS ACROSS NORTHWEST OREGON AND
SOUTHWEST WASHINGTON SATURDAY MORNING. A FEW THUNDERSTORMS EMBEDDED
IN THE RAIN MAY ENHANCE THE WIND THREAT SATURDAY MORNING. A SECOND
FRONT PUSHING INTO THE REGION FROM THE NORTHWEST SATURDAY NIGHT WILL
PRODUCE ANOTHER ROUND OF RAIN. ADDITIONAL SHOWERS WILL FOLLOW ON
SUNDAY. EXPECT COOL WEATHER AND ADDITIONAL ROUNDS OF SHOWERS FOR MUCH
OF THE UPCOMING WORK WEEK.
&&
.SHORT TERM...VISIBLE AND INFRARED SATELLITE IMAGERY SHOW AN
IMPRESSIVE SURFACE LOW PRESSURE UNDERGOING CYCLOGENESIS OFF THE
SOUTHERN OREGON COAST NEAR 130W. BUOY 46002 SLP CONTINUES TO DROP
BETWEEN 2-3MB/HOUR AND OUTPACE THE GFS AND EC FORECASTS CONSIDERABLY.
THE 00Z NAM SEEMS TO HAVE PICKED UP ON THIS ADDITIONAL DEVELOPMENT
AND IS AT LEAST CLOSER TO REALITY THAN THE 18Z GFS AND 12Z EC RUNS AT
THIS POINT. THE NAM FORECASTS THE LOW TO BOTTOM OUT AROUND 990MB OFF
THE MOUTH OF THE COLUMBIA RIVER AROUND 15Z SATURDAY BEFORE CLIPPING
CAPE FLATTERY ON ITS WAY NORTHWARD. SUSPECT IT WILL DROP SOLIDLY INTO
THE 980S. MEANWHILE...THE EC AND GFS HAVE CONTINUED TO TREND TOWARDS
GRADUALLY SHIFTING THE LOW TRACK SLIGHTLY FARTHER OFFSHORE...WHICH
EVEN WITH THE DEEPER DEVELOPMENT OBSERVED SO FAR...SHOULD HELP TO
KEEP THIS STORM FROM REALIZING ITS FULLEST POTENTIAL IN THE
WILLAMETTE VALLEY AND LOWER COLUMBIA RIVER VALLEY. WITH THAT
SAID...THE RAP BRINGS THE LOW PRESSURE ONSHORE OVER THE OLYMPIC
PENINSULA. THE RAP DID A DECENT JOB DEPICTING THE TRACK OF SEVERAL OF
OUR STRONGER LOW PRESSURES LAST YEAR SO IT IS TOUGH TO DISCOUNT IT
EVEN THOUGH IT IS CONSIDERABLY DIFFERENT THAN THE GLOBAL GFS AND EC
MODEL SOLUTIONS. GIVEN THE UNCERTAINTY IN THE FINAL TRACK OF THIS
LOW...ALL THE INHERITED HEADLINES SEEM REASONABLE AT THIS POINT.
HOWEVER...WILL NUDGE UP THE MENTION OF WIND GUSTS ALONG THE NORTH
OREGON AND SOUTH WASHINGTON COASTS AND ACROSS THE LOWER COLUMBIA
RIVER VALLEY AND PORTLAND METRO AREA WHERE A FEW HIGHER WIND GUSTS
SEEM POSSIBLE...ESPECIALLY IF THE LOW PRESSURE PUSHES ONTO THE
WASHINGTON COAST.
EXPECT THE WINDS TO COME ON RATHER SUDDENLY SATURDAY MORNING. THE
STRONG BURST OF WINDS SHOULD FIRST HIT THE CENTRAL OREGON COAST
BETWEEN 4 AM AND 6 AM...AND THE NORTH OREGON COAST...THE SOUTH
WASHINGTON COAST...AND THE WILLAMETTE VALLEY BETWEEN 7 AM AND 10 AM.
WHILE WINDS WILL STILL BE NOTABLY GUSTY SATURDAY AFTERNOON...THE
STRONGEST WINDS WILL LIKELY ONLY LAST FOR 2 TO 4 HOURS.
IN ADDITION...EXPANDED THE MENTION OF THUNDER TO A LARGER PORTION OF
THE CWA FOR SATURDAY MORNING AS THE NAM CONTINUES TO ADVERTISE
SUFFICIENT INSTABILITY TO PRODUCE A THUNDERSTORM OR TWO ALONG THE
FRONT. GIVEN THE AMPLE SHEAR...ANY STORMS THAT DO DEVELOP WILL NEED
TO BE MONITORED CLOSELY FOR PRODUCING LOCALIZED DAMAGING WINDS.
WHILE MOST EVERYONE SHOULD SEE A QUICK SHOT OF RAIN LATER TONIGHT AND
SATURDAY MORNING...SUSPECT TOMORROW WILL BE MORE DRY THAN WET FOR
MANY. HOWEVER...NOT ALL IS LOST AS MODELS HAVE TRENDED WETTER WITH A
SECOND FRONT DROPPING SOUTHEASTWARD OUT OF THE GULF OF ALASKA THAT
WILL PUSH A HEALTHY DOSE OF RAIN ACROSS THE AREA SATURDAY NIGHT.
DECENT ONSHORE FLOW AND INSTABILITY SHOULD LEAD TO MORE SHOWERS AND
POSSIBLY A WET THUNDERSTORM OR TWO SUNDAY.
BELOW AVERAGE TEMPERATURES AND ADDITIONAL ROUNDS OF WET WEATHER
APPEAR LIKELY NEXT WEEK. /NEUMAN
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE FALL-LIKE WEATHER
PATTERN WILL CONTINUE NEXT WEEK WITH PRIMARILY COOLER THAN NORMAL
TEMPERATURES...CLOUDY CONDITIONS...AND CHANCES FOR ADDITIONAL RAIN. A
TROUGH WILL REMAIN NEAR THE PACIFIC NORTHWEST COAST THROUGH MOST OF
THE PERIOD WITH SOME RAIN AT TIMES...ESPECIALLY DURING THE EARLY AND
MIDDLE PARTS OF NEXT WEEK. LITTLE CHANGE MADE TO THE CURRENT
FORECAST. TOLLESON
&&
.AVIATION...VFR CONDITIONS ACROSS THE AREA WITH CIGS PRIMARILY UP
ABOVE 10KFT. CIGS ALONG THE COAST WILL LOWER TO MVFR THIS EVENING
AROUND 03Z AS MORE SUBSTANTIAL SHOWERS MAKE THERE WAY ONTO THE
COAST. EXPECT MVFR CIGS TO CONTINUE OVERNIGHT WITH OCCASIONAL
DROPS IN VIS WITH HEAVIER SHOWERS. SHOWERS MOVES INLAND AROUND
08Z WHICH WILL LOWER CIGS AT INLAND TAF SITES TO LOW VFR...
OCCASIONALLY DROPPING TO MVFR THROUGH SATURDAY MORNING. SOUTHERLY
WINDS
ALONG THE COAST WILL INCREASE AROUND 09Z-12Z ALONG THE CENTRAL
OREGON COAST AND 12Z TO 15Z ALONG THE NORTH OREGON COAST...WITH
GUSTS UP TO 35 TO 45 KT. SOUTHERLY WINDS AT INLAND SITES START TO
INCREASE AROUND 11 TO 13Z WITH GUSTS TO 25 TO 35 KT AND
OCCASIONALLY TO 40 KT.
KPDX AND APPROACHES...VFR THIS EVENING. MORE WIDESPREAD SHOWERS
MOVE IN AROUND 08Z LOWERING CIGS TO LOW VFR WITH OCCASIONAL DROPS
TO MVFR. SOUTHERLY WINDS INCREASE AROUND 11Z WITH GUSTS TO 25 TO
35 KT AND OCCASIONAL GUST TO 40 KT POSSIBLE. -MCCOY
&&
.MARINE...FALL-LIKE LOW PRESSURE SYSTEM APPROACHES FROM APPROX 400
MI WEST OF NORTHERN CALIFORNIA. AS IT MOVES INTO THE WATERS EARLY
SATURDAY MORNING. WINDS WILL INCREASE OUT OF THE SOUTH TO AT LEAST
HIGH END GALES. MODELS HAVE STARTED TRENDING STRONGER...WHICH MAY
INDICATE AT LEAST A FEW STORM FORCE GUSTS...BUT WOULD LIKE TO SEE
ANOTHER RUN DEPICTING THIS SCENARIO BEFORE CONFIDENCE IMPROVES
ENOUGH TO UPGRADE TO STORM WARNING. AS WINDS INCREASE...SEAS WHICH
WILL BE AROUND 4 TO 5 FT TONIGHT THROUGH EARLY SATURDAY MORNING
WILL RAPIDLY BUILD TO 15 TO 17 FT. SEAS STAY UP AROUND 13 TO 17
FT UNTIL WINDS DECREASE SATURDAY EVENING. WINDS SHIFT MORE TO THE
SOUTH-SOUTHWEST BY SATURDAY EVENING AND FALL BACK DOWN TO 15 KT
GUSTING TO 20 TO 25 KT BY SUNDAY MORNING. SEAS ON SUNDAY WILL BE
AROUND 8 TO 10 FT WITH WINDS WITH WINDS DECREASING FURTHER TO 10
TO 15 KT BY SUNDAY EVENING.
UNSETTLED WEATHER CONTINUES INTO NEXT WEEK WITH SEAS STAYING
AROUND 7 TO 9 FT THROUGH AT LEAST MIDWEEK. -MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 8 AM TO 3 PM PDT SATURDAY FOR GREATER
PORTLAND METRO AREA-LOWER COLUMBIA.
HIGH WIND WARNING FROM 4 AM TO 1 PM PDT SATURDAY FOR CENTRAL
OREGON COAST.
WIND ADVISORY FROM 6 AM TO NOON PDT SATURDAY FOR CENTRAL
WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.
HIGH WIND WARNING FROM 6 AM TO 2 PM PDT SATURDAY FOR COAST RANGE
OF NORTHWEST OREGON-NORTH OREGON COAST.
HIGH WIND WARNING FROM 5 AM TO NOON PDT SATURDAY FOR CENTRAL
COAST RANGE OF WESTERN OREGON.
WA...WIND ADVISORY FROM 8 AM TO 3 PM PDT SATURDAY FOR GREATER
VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ COUNTY.
HIGH WIND WARNING FROM 8 AM TO 3 PM PDT SATURDAY FOR WILLAPA
HILLS.
HIGH WIND WARNING FROM 8 AM TO 2 PM PDT SATURDAY FOR SOUTH
WASHINGTON COAST.
PZ...GALE WARNING FROM 3 AM SATURDAY TO MIDNIGHT PDT SATURDAY NIGHT
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM
SATURDAY TO MIDNIGHT PDT SATURDAY NIGHT.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
440 AM CDT SAT AUG 29 2015
.UPDATE...
UPDATED TO INCREASE THE POPS FOR TODAY TO 40 PERCENT ACROSS
PORTIONS OF NORTHEAST AR THAT INCLUDES RANDOLPH...LAWRENCE AND
EXTREME WESTERN PORTIONS OF CLAY COUNTY. THE HRRR MODEL INDICATES
SHOWERS SPREADING INTO THIS AREA THIS MORNING. RADARS ALREADY
INDICATE SHOWERS JUST TO THE NORTHWEST GRADUALLY SLIPPING TO THE
SOUTHEAST.
JCL
&&
.DISCUSSION... /ISSUED 348 AM CDT SAT AUG 29 2015/
EARLY THIS MORNING...TEMPERATURES WERE A LITTLE WARMER THAN IN
RECENT DAYS RANGING FROM THE MIDDLE 60S TO LOWER 70S. MIDDLE AND
HIGH LEVEL CLOUDS STRETCHED FROM NORTHWEST TN AND THE MO BOOTHEEL
INTO NORTHEAST AR.
THE MIDSOUTH WILL BE AFFECTED BY TWO SYSTEMS THE NEXT COUPLE OF
DAYS...ONE AN UPPER LEVEL TROUGH APPROACHING FROM THE NORTHWEST
AND ANOTHER AN UPPER LEVEL LOW ALONG THE NORTHERN GULF COAST THAT
WILL LIFT NORTHEASTWARD. BOTH OF THESE FEATURES ARE FAIRLY WEAK.
THE LATEST GUIDANCE INDICATES HIGHER POPS ESPECIALLY FOR TONIGHT
AND SUNDAY THAN THE EARLIER GUIDANCE...DID RAISE THE POPS SOME BUT
CONFIDENCE IS NOT HIGH ENOUGH TO GO GREATER THAN 30 PERCENT POPS
ATTM. LATER FORECASTS MAY NEED TO RAISE THE POPS IN SOME LOCATIONS
DURING THIS TIMEFRAME.
FOR TODAY...AN UPPER LEVEL TROUGH FROM THE GREAT LAKES TO THE
CENTRAL PLAINS WILL MOVE SOUTHEASTWARD APPROACHING NORTHEAST AR.
INDICATED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR A SMALL
PORTION OF NORTHEAST AR TODAY. MEANWHILE...AN UPPER LEVEL LOW
WILL BE LOCATED ALONG THE MS AND AL COAST. THIS LOW WILL HELP TO
PUSH MORE MOIST AND UNSTABLE AIR INTO THE MIDSOUTH FROM THE EAST.
CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
FOR NORTHEAST MS AND THE TN RIVER VALLEY OF WEST TN. CLOUDS WILL
BE ON THE INCREASE ACROSS THE MIDSOUTH IN ASSOCIATION WITH BOTH OF
THESE SYSTEMS. TEMPERATURES WILL BE SEASONABLY WARM.
FOR TONIGHT...THE UPPER LEVEL TROUGH WILL PUSH INTO THE MIDSOUTH
FROM THE NORTHWEST WITH THE UPPER LOW ALONG THE CENTRAL GULF COAST
MOVING NORTHEASTWARD INTO CENTRAL AL. INDICATED A CHANCE OF
SHOWERS AND THUNDERSTORMS FOR MOST OF THE REGION.
ON SUNDAY...THE UPPER LEVEL LOW OVER CENTRAL AL WILL CONTINUE TO
PUSH NORTHEASTWARD WITH A WEAK BROAD UPPER LEVEL TROUGH OVER THE
MIDSOUTH. CONTINUED TO MENTION A CHANCE OF SHOWERS AND
THUNDERSTORMS. CLOUDS ARE EXPECTED TO DECREASE FROM THE SOUTHWEST.
MONDAY...AN UPPER LEVEL TROUGH WILL BE WEST OF THE MIDSOUTH WHILE
UPPER LEVEL RIDGING WILL BE TO THE EAST WITH WEAK SOUTHERLY FLOW
SURFACE AND ALOFT ACROSS THE REGION. THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY FOR A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS.
IT WILL FEEL LIKE SUMMER WITH PLENTY OF SUNSHINE BOOSTING
TEMPERATURES TO NEAR NORMAL READINGS.
TUESDAY...THE UPPER LEVEL RIDGE IS FORECAST TO BUILD ACROSS THE
MIDSOUTH FROM THE EAST SUPPRESSING MOST CONVECTION. KEPT POPS
BELOW MENTIONABLE LEVELS.
TOWARD THE MIDDLE AND END OF NEXT WEEK...INCREASING MOISTURE IS
FORECAST TO SPREAD INTO THE REGION FROM THE SOUTHEAST AS UPPER
LEVEL RIDGING WEAKENS. THIS WILL RESULT IN A RETURN OF A SMALL
CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. TEMPERATURES WILL
REMAIN SEASONABLY WARM TO HOT WITH NO COLD FRONTAL PASSAGES
EXPECTED.
JCL
&&
.AVIATION...
06Z TAF CYCLE
VFR. PATCHY FOG POSSIBLE AT KMKL. SSE WINDS 3-7 KTS.
30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATE
NWS PHOENIX AZ
420 AM MST SAT AUG 29 2015
.UPDATE...AVIATION AND FIRE WX SECTION.
&&
.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT WILL KEEP HIGH TEMPERATURES WELL ABOVE
SEASONAL NORMALS TODAY WITH HOTTER LOWER DESERTS REACHING OR
EXCEEDING 110. THERE WILL BE SUFFICIENT MOISTURE EAST OF THE LOWER
COLORADO RIVER TO SUPPORT ISOLATED TO SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THROUGH SUNDAY. STARTING MONDAY DRIER WESTERLY
FLOW ALOFT WILL PUSH THE MOISTURE OFF TO THE EAST LIMITING STORM
CHANCES PRIMARILY TO HIGHER TERRAIN AREAS TO THE EAST OF PHOENIX.
THERE WILL BE A GRADUAL COOLING TREND STARTING SUNDAY WITH CENTRAL
DESERTS HIGH TEMPERATURES DROPPING TO AROUND SEASONAL NORMALS BY THE
MIDDLE OF NEXT WEEK.
&&
.DISCUSSION... A STRONG UPPER LEVEL TROF CURRENTLY SPINNING OFF THE
PAC NW COAST HAS KEPT THE DOWNSTREAM UPPER RIDGE PUMPED UP OVER THE
DESERT SOUTHWEST...WITH H5 VALUES AROUND 593DM ACROSS ARIZONA PER
THE LATEST PLOT DATA. THE HIGH HEIGHTS ALOFT CONTINUED TO PRODUCE
HOT WEATHER ACROSS THE LOWER DESERTS WITH PHOENIX REACHING 109
YESTERDAY AND YUMA HITTING 111. LITTLE CHANGE IN THE PATTERN IS
EXPECTED TODAY AND CONTINUED HOT WEATHER IS ON TAP FOR THE LOWER
DESERTS...IN FACT PHOENIX IS EXPECTED TO REACH 110 TODAY WITH 110
PLUS READINGS OVER THE HOTTER WESTERN DESERTS. TEMPERATURES TODAY
WILL BE VERY CLOSE TO EXCESSIVE HEAT WARNING LEVELS.
WITH THE TROFFING SITTING OFF THE WEST COAST AND THE RIDGE PARKED
FIRMLY OVERHEAD...STEERING FLOW IS EITHER WEAK AND NONDESCRIPT OR
WEAK SOUTHERLY. PLENTY OF MOISTURE CONTINUES TO FLOW NORTH THRU
CENTRAL AND EASTERN ARIZONA WITH PWAT VALUES BETWEEN 1.25 AND 1.5
INCHES...AND SURFACE DEWPOINTS REMAIN HIGH AS WELL. AT 2 AM MOST OF
THE LOWER DESERTS RANGED FROM THE MID 50S TO THE MID 60S. EAST OF
THE LOWER COLORADO RIVER TODAY THERE WILL BE SUFFICIENT MOISTURE...
MLCAPE AND DAYTIME HEATING TO KEEP A THREAT GOING FOR AFTERNOON AND
EVENING STORMS...AND IN FACT SEVERAL LOCAL MESOSCALE MODELS
INCLUDING THE HRRR CALL FOR CONVECTION BREAKING OUT THIS AFTERNOON
OVER THE CENTRAL DESERTS...INCLUDING THE GREATER PHOENIX AREA...AND
PERSISTING INTO THE NIGHTTIME HOURS. POPS HAVE BEEN RAISED EAST OF
THE LOWER COLORADO RIVER INTO THE 15-20 PERCENT BALLPARK WITH
CHANCES FORECAST IN THE HIGHER TERRAIN EAST OF PHOENIX.
ON SUNDAY SIGNIFICANT SHORTWAVE ENERGY IS FORECAST TO MOVE INLAND
OVER THE PAC NORTHWEST AND IN RESPONSE FLOW OVER THE DESERT
SOUTHWEST AND ARIZONA BECOMES INCREASINGLY SOUTHWESTERLY. HEIGHTS
ALOFT FALL SLIGHTLY AND TEMPS SHOULD COOL A FEW DEGREES BUT THEY
WILL REMAIN WELL ABOVE NORMAL. THE FLOW WILL START TO SHIFT THE
DEEPER MOISTURE FURTHER TO THE EAST...BUT THERE WILL BE SUFFICIENT
MOISTURE AND INSTABILITY TO KEEP THE THREAT GOING FOR AFTN/EVE STORMS
ACROSS SOUTH CENTRAL ARIZONA. POPS WILL BE SIMILAR TO TODAY...BUT
SLIGHTLY LOWER WEST OF MARICOPA COUNTY.
GFS AND ECMWF OPERATIONAL RUNS AS WELL AS ENSEMBLE GUIDANCE CONTINUE
TO CALL FOR A GRADUAL DRYING AND COOLING TREND TO OCCUR OVER THE
ENTIRE WORK WEEK NEXT WEEK...AS TROFFING ALOFT INITIALLY DEVELOPS
ALONG THE WEST COAST AND PLACES A DRYING SOUTHWEST FLOW ALOFT ACROSS
SERN CALIFORNIA AND ARIZONA. AS THE WEEK PROGRESSES THE TROFFING
STARTS TO PUSH INLAND AND AS THIS HAPPENS TEMPERATURES WILL COOL
DOWN TO NEAR SEASONAL NORMALS. MONDAY INTO TUESDAY THE TROF AXIS
REMAINS ALONG THE WEST COAST...AND FLOW IS NOT SUFFICIENT TO
COMPLETELY SCOUR OUT THE MOISTURE OVER ALL OF SOUTH CENTRAL AZ. FOR
THE MOST PART THE THREAT OF AFTERNOON AND EVENING STORMS WILL BE
CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX BUT CHANCES IN THE
GREATER PHOENIX AREA WILL CERTAINLY NOT BE ZERO...THEY WILL HOVER IN
THE 5 TO 10 PERCENT BALLPARK. FOR THE LATTER HALF OF THE WORKWEEK AS
THE TROF AXIS SHIFTS INLAND AND SOUTHWEST FLOW ALOFT BECOMES
STRONGER...MOISTURE WILL BE PUSHED OFF TO THE EAST AND EVENTUALLY
ANY THREAT FOR STORMS WILL FOCUS OVER HIGHER TERRAIN AREAS TO THE
EAST OF GLOBE WITH SKIES IN THE GREATER PHOENIX AREA MOSTLY SUNNY
EACH DAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...
EASTERLY FLOW ACROSS THE PHX AREA WILL CONTINUE INTO THE MID
AFTERNOON AS WESTERLY WINDS WILL BE A LITTLE SLOW TO
DEVELOP...LIKELY AFTER 22Z. ENOUGH MOISTURE REMAINS FOR SOME
SHOWERS/STORMS TO DEVELOP OVER THE MTNS OF ARIZONA...INCLUDING WEST
AND SOUTH OF PHX WHICH MAY IMPACT ARRIVAL/DEPARTURE ROUTES.
POSSIBLE...THOUGH NOT ENOUGH TO EXPLICITLY PUT IN TAFS...OF OUTFLOW
COMING IN THIS EVENING PRODUCING SOME BLDU AND PERHAPS A FEW
SHOWERS/STORMS IN THE PHX AREA ITSELF.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WIND PATTERNS WITH LITTLE CLOUD COVER EXPECTED. FEW
STORMS BETWEEN KBLH-KPHX-KNYL BETWEEN 19Z-01Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER... MONDAY THROUGH FRIDAY... OVERALL THE WEATHER
PATTERN WILL BE ON A GENTLE COOLING AND DRYING TREND. FOR MUCH OF
THE WEEK...ANY RAIN CHANCES WILL REMAIN OVER THE HIGHER ELEVATIONS
OF EASTERN ARIZONA. NO SIGNIFICANT WINDS THOUGH THE AFTERNOONS MAY
BE JUST A BIT BREEZIER THAN USUAL.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CB
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
540 AM PDT SAT AUG 29 2015
.SYNOPSIS...MUCH COOLER WEATHER IS FORECAST FOR THIS WEEKEND INTO
NEXT WEEK. OUTSIDE OF A SLIGHT CHANCE FOR RAIN ALONG THE SONOMA
COAST THIS MORNING...DRY WEATHER IS EXPECTED.
&&
.UPDATE...AS OF 5:40 AM PDT SATURDAY...RADAR CONTINUES TO SHOW A
LACK OF ANY RADAR RETURNS ACROSS THE NORTH BAY OR COASTAL WATERS AND
WITH THE HRRR NOW GREATLY BACKING OFF ON RAINFALL DECIDED TO
REMOVE MENTION OF RAIN FOR MOST OF OUR AREA. DID KEEP A SLIGHT
CHANCE FOR COASTAL SONOMA COUNTY IN CASE SOME LIGHT RAIN FINALLY
HITS THAT AREA. FOR THE REST OF THE CWA...NOW APPEARS THAT WE WILL
STAY DRY THROUGH THE DAY.
.DISCUSSION...AS OF 3:20 AM PDT SATURDAY...COASTAL RADARS HAVE
PICKED UP ECHOES THROUGH THE OVERNIGHT HOURS ALTHOUGH TO THIS
POINT VIRTUALLY ALL HAVE BEEN NORTH OF OUR CWA. LATEST RUN OF THE
HRRR CONTINUES TO BE IN GOOD AGREEMENT WITH PREVIOUS RUNS AND
BRINGS LIGHT RAIN ACROSS THE NORTH BAY THIS MORNING AND
POTENTIALLY DOWN INTO THE SF BAY AREA AS A COLD FRONT MOVES
ACROSS. WILL BE INTERESTING TO SEE HOW WELL THE HRRR ENDS UP
DOING. EARLIER THIS YEAR WE FOUND THAT IN SOME CASES IT NAILED THE
RAINFALL FOR THE DAY WHILE OTHER TIMES IT WOULD BRING RAIN ACROSS
WHILE THE GROUND TRUTH WAS FAR DRIER.
MORE NOTABLE THAN THE POTENTIAL FOR LIGHT RAIN WILL BE MUCH
COOLER WEATHER THIS WEEKEND AS THE MARINE LAYER DEEPENS WHILE THE
FLOW AT THE SURFACE BECOMES MORE WESTERLY. AT THE SAME TIME THE
STRONG RIDGE OF HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS WILL
PROGRESS TO THE EAST AS THE LONGWAVE TROF ADVANCES TO THE COAST.
INLAND SPOTS WILL GENERALLY SEE THE BIGGEST DROPS COMPARED TO
YESTERDAY WITH HIGHS AS MUCH AS 15 TO 20 DEGREES COOLER. COASTAL
TEMPS WILL GENERALLY BE 5 TO 10 DEGREES COOLER. THE FRONTAL
PASSAGE WILL ALSO TRIGGER BREEZY CONDITIONS WITH LOCALLY GUSTY
WESTERLY WINDS.
SYNOPTICALLY THE NEXT 10 DAYS ARE SHAPING UP WITH THE LONGWAVE
PATTERN FAIRLY STAGNANT...TROF OVER THE WEST WITH A RIDGE TO THE
EAST. THIS WILL TRANSLATE TO TEMPS AT OR BELOW NORMAL. ANY
RAINFALL IS EXPECTED TO FALL NORTH OUR OUR REGION. FOR WHAT IT`S
WORTH...THE 16 DAY GFS SHOWS DRY WEATHER AFTER TODAY FOR OUR
ENTIRE AREA.
&&
.AVIATION...AS OF 4:45 AM PDT SATURDAY...LOW CLOUDS THAT CAME IN
EARLIER THIS EVENING IS MIXING OUT AHEAD OF AN APPROACHING FRONTAL
SYSTEM AS SEVERAL AREA METARS ARE CURRENTLY REPORTING SCT CLOUDS.
SATELLITE IMAGE SHOWS LOW CLOUDS ASSOCIATED WITH THE FRONT
JUST OFFSHORE. THUS WIDESPREAD CIGS WILL RETURN TO THE AREA AFTER
14Z BUT CIGS WILL BE HIGHER AT OR ABOVE 1500 FEET. CLEARING TAKES
PLACE BY AFTERNOON AS THE BACK EDGE OF THE FRONT MOVES THROUGH.
BREEZY POST-FRONTAL WEST WINDS POSSIBLE IN THE AFTERNOON.
VICINITY OF KSFO...MVFR CIGS BY 14Z CLEARING BY 21Z.
CONFIDENCE IS MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...IFR CIGS WILL LIFT TO MVFR CIGS
AFTER 14-15Z. CIGS ARE EXPECTED TO FURTHER LIFT AND MIX OUT BY
AROUND 18Z. CONFIDENCE IS MODERATE.
&&
.BEACHES...AS OF 4:30 AM PDT SATURDAY...A LONG PERIOD WEST SWELL
HAS ARRIVED AND WILL CONTINUE TO ADVANCE ON WEST FACING BEACHES
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THESE LONG PERIOD
SWELLS CAN PRODUCE HAZARDOUS RIP CURRENTS THAT CAN QUICKLY PULL
SWIMMERS OUT TO SEA. THE HIGHEST RISK OF HAZARDOUS CONDITIONS WILL
BE THIS WEEKEND WHEN ONSHORE WINDS WEAKEN AND THE PERIOD INCREASES
FROM 15 TO 18 SECONDS. SWIMMERS CAUGHT IN A RIP CURRENT SHOULD
SWIM PARALLEL TO THE COAST TO ESCAPE THE RIP CURRENTS.
&&
.MARINE...AS OF 4:30 AM PDT SATURDAY...A FRONTAL SYSTEM WILL MOVE
THROUGH THE AREA TODAY. NORTHWEST WINDS WILL INCREASE IN THE
SOUTHERN WATERS THIS AFTERNOON AND OVER THE NORTHERN WATERS SUNDAY
BEHIND THE FRONT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 PM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: W PI
MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
500 AM PDT SAT AUG 29 2015
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF LIGHT
RAIN TO THE NORTHERN PORTION OF OUR DISTRICT INTO THE MORNING
HOURS TODAY. MUCH COOLER WEATHER IS FORECAST FOR THIS WEEKEND.
DRY AND SEASONABLY COOL WEATHER IS EXPECTED NEXT WEEK.
&&
.DISCUSSION...AS OF 3:20 AM PDT SATURDAY...COASTAL RADARS HAVE
PICKED UP ECHOES THROUGH THE OVERNIGHT HOURS ALTHOUGH TO THIS
POINT VIRTUALLY ALL HAVE BEEN NORTH OF OUR CWA. LATEST RUN OF THE
HRRR CONTINUES TO BE IN GOOD AGREEMENT WITH PREVIOUS RUNS AND
BRINGS LIGHT RAIN ACROSS THE NORTH BAY THIS MORNING AND
POTENTIALLY DOWN INTO THE SF BAY AREA AS A COLD FRONT MOVES
ACROSS. WILL BE INTERESTING TO SEE HOW WELL THE HRRR ENDS UP
DOING. EARLIER THIS YEAR WE FOUND THAT IN SOME CASES IT NAILED THE
RAINFALL FOR THE DAY WHILE OTHER TIMES IT WOULD BRING RAIN ACROSS
WHILE THE GROUND TRUTH WAS FAR DRIER.
MORE NOTABLE THAN THE POTENTIAL FOR LIGHT RAIN WILL BE MUCH
COOLER WEATHER THIS WEEKEND AS THE MARINE LAYER DEEPENS WHILE THE
FLOW AT THE SURFACE BECOMES MORE WESTERLY. AT THE SAME TIME THE
STRONG RIDGE OF HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS WILL
PROGRESS TO THE EAST AS THE LONGWAVE TROF ADVANCES TO THE COAST.
INLAND SPOTS WILL GENERALLY SEE THE BIGGEST DROPS COMPARED TO
YESTERDAY WITH HIGHS AS MUCH AS 15 TO 20 DEGREES COOLER. COASTAL
TEMPS WILL GENERALLY BE 5 TO 10 DEGREES COOLER. THE FRONTAL
PASSAGE WILL ALSO TRIGGER BREEZY CONDITIONS WITH LOCALLY GUSTY
WESTERLY WINDS.
SYNOPTICALLY THE NEXT 10 DAYS ARE SHAPING UP WITH THE LONGWAVE
PATTERN FAIRLY STAGNANT...TROF OVER THE WEST WITH A RIDGE TO THE
EAST. THIS WILL TRANSLATE TO TEMPS AT OR BELOW NORMAL. ANY
RAINFALL IS EXPECTED TO FALL NORTH OUR OUR REGION. FOR WHAT IT`S
WORTH...THE 16 DAY GFS SHOWS DRY WEATHER AFTER TODAY FOR OUR
ENTIRE AREA.
&&
.AVIATION...AS OF 4:45 AM PDT SATURDAY...LOW CLOUDS THAT CAME IN
EARLIER THIS EVENING IS MIXING OUT AHEAD OF AN APPROACHING FRONTAL
SYSTEM AS SEVERAL AREA METARS ARE CURRENTLY REPORTING SCT CLOUDS.
SATELLITE IMAGE SHOWS LOW CLOUDS ASSOCIATED WITH THE FRONT
JUST OFFSHORE. THUS WIDESPREAD CIGS WILL RETURN TO THE AREA AFTER
14Z BUT CIGS WILL BE HIGHER AT OR ABOVE 1500 FEET. CLEARING TAKES
PLACE BY AFTERNOON AS THE BACK EDGE OF THE FRONT MOVES THROUGH.
BREEZY POST-FRONTAL WEST WINDS POSSIBLE IN THE AFTERNOON.
VICINITY OF KSFO...MVFR CIGS BY 14Z CLEARING BY 21Z.
CONFIDENCE IS MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...IFR CIGS WILL LIFT TO MVFR CIGS
AFTER 14-15Z. CIGS ARE EXPECTED TO FURTHER LIFT AND MIX OUT BY
AROUND 18Z. CONFIDENCE IS MODERATE.
&&
.BEACHES...AS OF 4:30 AM PDT SATURDAY...A LONG PERIOD WEST SWELL
HAS ARRIVED AND WILL CONTINUE TO ADVANCE ON WEST FACING BEACHES
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THESE LONG PERIOD
SWELLS CAN PRODUCE HAZARDOUS RIP CURRENTS THAT CAN QUICKLY PULL
SWIMMERS OUT TO SEA. THE HIGHEST RISK OF HAZARDOUS CONDITIONS WILL
BE THIS WEEKEND WHEN ONSHORE WINDS WEAKEN AND THE PERIOD INCREASES
FROM 15 TO 18 SECONDS. SWIMMERS CAUGHT IN A RIP CURRENT SHOULD
SWIM PARALLEL TO THE COAST TO ESCAPE THE RIP CURRENTS.
&&
.MARINE...AS OF 4:30 AM PDT SATURDAY...A FRONTAL SYSTEM WILL MOVE
THROUGH THE AREA TODAY. NORTHWEST WINDS WILL INCREASE IN THE
SOUTHERN WATERS THIS AFTERNOON AND OVER THE NORTHERN WATERS SUNDAY
BEHIND THE FRONT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 PM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: W PI
MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
321 AM PDT SAT AUG 29 2015
.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING A CHANCE OF LIGHT
RAIN TO THE NORTHERN PORTION OF OUR DISTRICT INTO THE MORNING
HOURS TODAY. MUCH COOLER WEATHER IS FORECAST FOR THIS WEEKEND.
DRY AND SEASONABLY COOL WEATHER IS EXPECTED NEXT WEEK.
&&
.DISCUSSION...AS OF 3:20 AM PDT SATURDAY...COASTAL RADARS HAVE
PICKED UP ECHOES THROUGH THE OVERNIGHT HOURS ALTHOUGH TO THIS
POINT VIRTUALLY ALL HAVE BEEN NORTH OF OUR CWA. LATEST RUN OF THE
HRRR CONTINUES TO BE IN GOOD AGREEMENT WITH PREVIOUS RUNS AND
BRINGS LIGHT RAIN ACROSS THE NORTH BAY THIS MORNING AND
POTENTIALLY DOWN INTO THE SF BAY AREA AS A COLD FRONT MOVES
ACROSS. WILL BE INTERESTING TO SEE HOW WELL THE HRRR ENDS UP
DOING. EARLIER THIS YEAR WE FOUND THAT IN SOME CASES IT NAILED THE
RAINFALL FOR THE DAY WHILE OTHER TIMES IT WOULD BRING RAIN ACROSS
WHILE THE GROUND TRUTH WAS FAR DRIER.
MORE NOTABLE THAN THE POTENTIAL FOR LIGHT RAIN WILL BE MUCH
COOLER WEATHER THIS WEEKEND AS THE MARINE LAYER DEEPENS WHILE THE
FLOW AT THE SURFACE BECOMES MORE WESTERLY. AT THE SAME TIME THE
STRONG RIDGE OF HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS WILL
PROGRESS TO THE EAST AS THE LONGWAVE TROF ADVANCES TO THE COAST.
INLAND SPOTS WILL GENERALLY SEE THE BIGGEST DROPS COMPARED TO
YESTERDAY WITH HIGHS AS MUCH AS 15 TO 20 DEGREES COOLER. COASTAL
TEMPS WILL GENERALLY BE 5 TO 10 DEGREES COOLER. THE FRONTAL
PASSAGE WILL ALSO TRIGGER BREEZY CONDITIONS WITH LOCALLY GUSTY
WESTERLY WINDS.
SYNOPTICALLY THE NEXT 10 DAYS ARE SHAPING UP WITH THE LONGWAVE
PATTERN FAIRLY STAGNANT...TROF OVER THE WEST WITH A RIDGE TO THE
EAST. THIS WILL TRANSLATE TO TEMPS AT OR BELOW NORMAL. ANY
RAINFALL IS EXPECTED TO FALL NORTH OUR OUR REGION. FOR WHAT IT`S
WORTH...THE 16 DAY GFS SHOWS DRY WEATHER AFTER TODAY FOR OUR
ENTIRE AREA.
&&
.AVIATION...AS OF 10:46 PM PDT FRIDAY...LOW CLOUDS HAVE ADVANCED
INTO THE SAN FRANCISCO BAY MUCH FASTER THAN PREVIOUSLY FORECAST.
HOWEVER...LOW CLOUDS HAVE NOT YET IMPACTED THE MONTEREY
TERMINALS...BUT ARE EXPECTED TO SHORTLY. THERE IS A FRONT MOVING
TOWARD THE COAST TONIGHT WHICH WILL LIFT THE LOW CLOUDS TO MVFR
SATURDAY MORNING. THE CLOUDS WILL MIX OUT BY LATE MORNING EARLY
AFTERNOON AS THE FRONT PASSES TO THE EAST.
VICINITY OF KSFO...IFR BASES BKN-OVC009 HAVE ARRIVE AT THE
TERMINALS FOR THE EVENING. THESE CLOUDS WILL LIFT AND BECOME
CUMULUS TYPE CLOUDS BEGINNING AROUND 1600Z AS THE FRONT
APPROACHES THE TERMINALS. THE CLOUDS WILL FURTHER LIFT AND MIX OUT
BETWEEN 1800 AND 2000Z.
CONFIDENCE IS MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR IS ANTICIPATED TO GIVE WAY TO
MVFR BKN-OVC015 BY AROUND 0800Z FURTHER DETERIORATING TO IFR BKN-
OVC008 BY AROUND 1100Z. CLOUDS ARE EXPECTED TO LIFT AND BECOME
MORE CUMULUS TYPE BEGINNING AROUND 1500Z AS THE FRONT APPROACHES
THE TERMINALS. THE CLOUDS ARE ANTICIPATED TO FURTHER LIFT AND MIX
OUT BY AROUND 1800Z
CONFIDENCE IS MODERATE.
&&
.BEACHES...AS OF 11:30 AM PDT FRIDAY...A LONG PERIOD WEST SWELL
HAS ARRIVED AND WILL CONTINUE TO ADVANCE ON WEST FACING BEACHES
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THESE LONG PERIOD
SWELLS CAN PRODUCE HAZARDOUS RIP CURRENTS THAT CAN QUICKLY PULL
SWIMMERS OUT TO SEA. THE HIGHEST RISK OF HAZARDOUS CONDITIONS WILL
BE THIS WEEKEND WHEN ONSHORE WINDS WEAKEN AND THE PERIOD
INCREASES FROM 15 TO 18 SECONDS. SWIMMERS CAUGHT IN A RIP CURRENT
SHOULD SWIM PARALLEL TO THE COAST TO ESCAPE THE RIP CURRENTS.
&&
.MARINE...AS OF 3:20 PM PDT FRIDAY...A FRONTAL SYSTEM WILL MOVE
THROUGH THE AREA TODAY. NORTHWEST WINDS WILL INCREASE IN THE
SOUTHERN WATERS THIS AFTERNOON AND OVER THE NORTHERN WATERS SUNDAY
BEHIND THE FRONT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 PM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: LARRY
MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1006 AM EDT SAT AUG 29 2015
.DISCUSSION...
...A CHANCE FOR HEAVY RAIN ESPECIALLY SUNDAY AND MONDAY...
TODAY/TONIGHT...LOW LEVEL FLOW WILL BE FROM THE EAST/SOUTHEAST WITH
SPEEDS INCREASING TONIGHT...WHICH WILL FAVOR INTERIOR CONVECTION
THIS AFTERNOON AND THE COAST TONIGHT. MID LEVEL FLOW WILL REMAIN
MOSTLY OUT OF THE SOUTH SO SOME DEBRIS RAINFALL FROM AFTERNOON
CONVECTION SHOULD AFFECT THE NORTH COAST LATE IN THE DAY.
MORNING GPS PRECIPITABLE WATER DATA...MIAMI SOUNDING AND GFS
FORECAST SOUNDINGS SHOW SOME ELEVATED DRY AIR. MORNING SATELLITE
SHOWS LITTLE DEEP CONVECTION OFF TO OUR EAST...SO CURRENT FORECAST
FOR TODAY WITH LOWER POPS ALONG THE COAST SOUTH OF THE CAPE LOOKS
GOOD. THE LATEST HRRR MODEL CONCENTRATES THE HEAVY RAIN THIS
AFTERNOON NEAR/WEST OF I-4...WHICH LOOKS GOOD SINCE THIS SEA BREEZE
CONVECTION WILL BE MOVING INTO AN AREA WITH DIVERGENCE ALOFT. THERE
WILL BE A LITTLE MORE STEERING FLOW TODAY SO STORMS SHOULD SHOW A
LITTLE MORE MOTION TO THE NORTH/NORTHWEST...SO EXPECT THE INTERIOR
STORMS WILL HAVE MAX AMOUNTS AROUND 2 INCHES.
SOUTHEAST FLOW INCREASING TONIGHT SHOULD PRODUCE INCREASED SHOWER
AND STORM CHANCES ALONG THE COAST...ESPECIALLY SOUTH OF THE CAPE.
ALL OF THE ABOVE THINKING IS PRETTY MUCH INCORPORATED INTO THE
PREVIOUS FORECAST AND LITTLE CHANGE IS PLANNED.
&&
.AVIATION...MOSTLY VFR THIS MORNING EXCEPT BRIEF MVFR AS CUMULUS
FORM. STILL EXPECT INCREASING COVERAGE OF SHOWERS AND STORMS
PRODUCING TEMPO IFR/MVFR REDUCTIONS MAINLY ACROSS INTERIOR TAF SITES
MID-LATE AFTERNOON.
AREAS OF LINGERING RAIN AND ISOLATED STORMS SHOULD EXTEND THROUGH
EARLY EVENING OVER THE INTERIOR AND POSSIBLY AT DAB. AN INCREASING
MOIST SE FLOW WILL LEAD TO SCATTERED SHRA AND ISOLATED TSRA OVER THE
WATERS THAT WILL PUSH ONSHORE OVERNIGHT...ESPECIALLY AFFECTING
SITES BETWEEN MLB AND SUA.
&&
.MARINE...
TODAY/TONIGHT...PRESSURE GRADIENT WILL GRADUALLY TIGHTEN AS LOW
PRESSURE TROUGH FROM REMNANTS OF ERIKA LIFTS INTO THE FLORIDA
STRAITS. EAST/SOUTHEAST WINDS SHOULD INCREASE ENOUGH TONIGHT FOR
EXERCISE CAUTION CONDITIONS IN THE SOUTH. ELSEWHERE THERE WILL BE
MORE WIND CHOP SO CONDITIONS STARTING OUT SUNDAY LOOK POOR FOR SMALL
CRAFT OVER ALL OF THE WATERS.
SUN-WED...E/SE MARITIME FLOW INCREASES SUN/MON AS REMNANT TROUGH
FROM ERIKA DRAWS NEARER TO THE SW PENINSULA. INCREASE IN FLOW WILL
PROMOTE AREAS OF HEAVY RAIN WITH EMBEDDED STORMS WHICH WILL
SUBSTANTIALLY DROP LOCAL VISIBILITIES AT TIMES ACROSS THE WATERS S
OF THE CAPE. WINDS 15 TO 20 KNOTS SUN WITH SEAS TO 6 FT THERE. WINDS
WILL RELAX A LITTLE GOING INTO MON BUT SEAS WILL BE A LITTLE SLOWER
TO SLACKEN AS SMALL CRAFT WILL BE URGED TO EXERCISE CAUTION THRU
MON. WINDS TO 15 KNOTS NORTH OF THE CAPE BUT WITH THE SAME 6 FT SEAS.
BOATING CONDITIONS MORE ACCEPTABLE BY MID-WEEK WITH SE WINDS 10
KNOTS OR LESS AND SEAS 2-3 FT NEARSHORE AND 3-4 FT OFFSHORE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
IMPACT WX....SEDLOCK/VOLKMER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1014 AM EDT SAT AUG 29 2015
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL REMAIN STALLED JUST OFF TO THE SOUTH
OF THE FORECAST AREA...WITH DRY SURFACE HIGH PRESSURE REMAINING
ANCHORED OVER THE WESTERN AND CENTRAL CAROLINAS. INCREASING
ATMOSPHERIC MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN
AND WESTERN PORTIONS OF OUR REGION TODAY...AND INTO REMAINING
AREAS SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN UPPER PATTERN CONTINUES TO BE DOMINATED BY THE WESTERN
ATLANTIC RIDGE...AND CUTOFF LOW IN THE NORTHERN GULF OF MEXICO.
ACROSS THE REGION...WEAK SURFACE TROUGH WILL REMAIN ACROSS THE
SOUTHERN PORTIONS OF THE CSRA...EXTENDING WESTWARD INTO CENTRAL
GA. THIS BOUNDARY MAY MOVE NORTHWARD SLIGHTLY THROUGHOUT THE
DAY...BUT DRIER AIR NORTH OF THIS FRONT WILL STILL DOMINATE MOST
OF THE CWA TODAY. MOST MODELS KEEP A DRY FORECAST ACROSS THE
CWA...WITH POSSIBLE SLIGHT CHANCE POPS ACROSS THE EXTREME SOUTHERN
CSRA WHERE MOISTURE RETURN MAY BE A LITTLE BETTER LATER THIS
AFTERNOON. LATEST HRRR DOES TRY TO BRING SHOWERS INTO THE EASTERN
CWA...BUT DUE TO THE AMOUNT OF DRY AIR CURRENTLY IN PLACE...HAVE
GONE WITH THE MODEL CONSENSUS AND KEPT THE THE MAJORITY OF THE
AREA DRY TODAY. SOME THIN HIGH CLOUDINESS WILL MOVE ACROSS THE
REGION...WHICH MAY HAVE A MINOR IMPACT ON AFTERNOON
HIGHS...KEEPING TEMPS VERY SIMILAR TO PREVIOUS DAYS READINGS. HAVE
GONE WITH HIGHS IN THE UPPER 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
THE UPPER LOW OVER THE NORTH-CENTRAL GULF WILL LIFT NORTHEASTWARD
TONIGHT INTO SUNDAY WITH MOISTURE EXPECTED TO CONTINUE TRENDING
NORTH. GFS MODEL PRECIPITABLE WATER VALUES INCREASE TO NEAR 2
INCHES FOR MOST ALL OF THE FA BY SUNDAY AFTERNOON. MODELS INDICATE
A POP GRADIENT WITH LOWER POPS NORTH/HIGHER POPS SOUTH. MODEL
GUIDANCE HAS BEEN TRENDING WETTER AND COOLER SO HAVE INCREASED
POPS AND ADJUSTED MAX TEMPS DOWN...IN THE MID TO UPPER 80S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST.
MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL
CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO THE
EASTERN GULF OF MEXICO BY LATE SUN...AND NORTHWARD INTO N FL/S GA
VICINITY BY WED. EVEN WITHOUT THE CYCLONE IN PLAY...IT APPEARS
SUFFICIENT ATMOSPHERIC MOISTURE WOULD PROVIDE PREMISE FOR
SCATTERED DIURNAL CONVECTION OVER OUR FA ANYWAY. DUE TO
UNCERTAINTIES REGARDING POSSIBLE IMPACT OF ERIKA ON OUR
REGION...WILL CONTINUE TO MAINTAIN ONGOING FORECAST OF CHANCE
POPS...TRENDED A LITTLE HIGHER TO THE SOUTH. GENERALLY BLENDED
LATEST GUIDANCE WITH ONGOING FORECAST.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
MAINLY MID AND HIGH LEVEL CLOUDS ACROSS THE AREA LATE THIS
MORNING. DO NOT EXPECT ANY CONVECTION TO IMPACT TAF
SITES...MAINLY DUE TO THE BEST MOISTURE REMAINING SOUTH OF THE
SITES.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
638 AM EDT SAT AUG 29 2015
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL REMAIN STALLED JUST OFF TO THE SOUTH
OF THE FORECAST AREA...WITH DRY SURFACE HIGH PRESSURE REMAINING
ANCHORED OVER THE WESTERN AND CENTRAL CAROLINAS. INCREASING
ATMOSPHERIC MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN
AND WESTERN PORTIONS OF OUR REGION TODAY...AND INTO REMAINING
AREAS SUNDAY.
&&
.NEAR TERM /TODAY/...
LITTLE CHANGE FROM PREVIOUS THINKING. MAIN UPPER PATTERN
CONTINUES TO BE DOMINATED BY THE WESTERN ATLANTIC RIDGE...AND
CUTOFF LOW IN THE NORTHERN GULF OF MEXICO. ACROSS THE
REGION...WEAK SURFACE TROUGH WILL REMAIN ACROSS THE SOUTHERN
PORTIONS OF THE CSRA...EXTENDING WESTWARD INTO CENTRAL GA. THIS
BOUNDARY MAY MOVE NORTHWARD SLIGHTLY THROUGHOUT THE DAY...BUT
DRIER AIR NORTH OF THIS FRONT WILL STILL DOMINATE MOST OF THE CWA
TODAY. MOST MODELS KEEP A DRY FORECAST ACROSS THE CWA...WITH
POSSIBLE SLIGHT CHANCE POPS ACROSS THE EXTREME SOUTHERN CSRA WHERE
MOISTURE RETURN MAY BE A LITTLE BETTER LATER THIS AFTERNOON.
LATEST HRRR DOES TRY TO BRING SHOWERS INTO THE EASTERN CWA...BUT
DUE TO THE AMOUNT OF DRY AIR CURRENTLY IN PLACE...HAVE GONE WITH
THE MODEL CONSENSUS AND KEPT THE THE MAJORITY OF THE AREA DRY
TODAY. SOME THIN HIGH CLOUDINESS WILL MOVE ACROSS THE REGION...WHICH
MAY HAVE A MINOR IMPACT ON AFTERNOON HIGHS...KEEPING TEMPS VERY
SIMILAR TO PREVIOUS DAYS READINGS. HAVE GONE WITH HIGHS IN THE
UPPER 80S.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
THE UPPER LOW OVER THE NORTH-CENTRAL GULF WILL LIFT NORTHEASTWARD
TONIGHT INTO SUNDAY WITH MOISTURE EXPECTED TO CONTINUE TRENDING
NORTH. GFS MODEL PRECIPITABLE WATER VALUES INCREASE TO NEAR 2
INCHES FOR MOST ALL OF THE FA BY SUNDAY AFTERNOON. MODELS INDICATE
A POP GRADIENT WITH LOWER POPS NORTH/HIGHER POPS SOUTH. MODEL
GUIDANCE HAS BEEN TRENDING WETTER AND COOLER SO HAVE INCREASED
POPS AND ADJUSTED MAX TEMPS DOWN...IN THE MID TO UPPER 80S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST.
MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL
CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO THE
EASTERN GULF OF MEXICO BY LATE SUN...AND NORTHWARD INTO N FL/S GA
VICINITY BY WED. EVEN WITHOUT THE CYCLONE IN PLAY...IT APPEARS
SUFFICIENT ATMOSPHERIC MOISTURE WOULD PROVIDE PREMISE FOR
SCATTERED DIURNAL CONVECTION OVER OUR FA ANYWAY. DUE TO
UNCERTAINTIES REGARDING POSSIBLE IMPACT OF ERIKA ON OUR
REGION...WILL CONTINUE TO MAINTAIN ONGOING FORECAST OF CHANCE
POPS...TRENDED A LITTLE HIGHER TO THE SOUTH. GENERALLY BLENDED
LATEST GUIDANCE WITH ONGOING FORECAST.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
HIGHER MOISTURE ACROSS THE CSRA TAF SITES BEING SHOWN BY HIGHER
DEWPOINTS THERE. MIDLANDS SITES...AND AREAS FURTHER NORTH...ARE
SHOWING SLIGHTLY DRIER AIR. MODELS CONTINUE TO SHOW VFR CONDITIONS
EARLY THIS MORNING AND THROUGH THE DAY. WITH HIGHER MOISTURE
ACROSS AGS...CAN NOT RULE OUT A DROP INTO MVFR VISIBILITIES
BRIEFLY THROUGH SUNRISE. THIN CIRRUS MOVING INTO THE REGION SHOULD
ALSO HELP LIMIT ANY WIDESPREAD FOG/STRATUS FORMATION THIS MORNING.
DO NOT EXPECT ANY CONVECTION TO IMPACT TAF SITES...MAINLY DUE TO
THE BEST MOISTURE REMAINING SOUTH OF THE SITES.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1019 AM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 1018 AM CDT SAT AUG 29 2015
SCATTERED SHOWERS CONTINUE TO PUSH ACROSS AREAS MAINLY EAST OF
I-55 THIS MORNING...WITH SOME SPRINKLES STARTING TO MOVE INTO
PARTS OF SOUTHEAST ILLINOIS AS WELL. MORNING SOUNDING FROM OUR
OFFICE SHOWED QUITE A BIT OF DRY AIR BELOW 12000 FEET...WHICH HAS
HELPED KEEP MOST OF THE RAIN LIMITED TO A FEW HUNDREDTHS OF
ACCUMULATION. LATEST RAP MODEL SOUNDINGS SHOW SOME MOISTENING OF
THE COLUMN DOWN TO ABOUT 5000 FEET OVER THE NEXT FEW HOURS...
HOWEVER SOME DRIER AIR IS ALSO EVIDENT ON WATER VAPOR IMAGERY
DROPPING SOUTHWARD AHEAD OF A FAST MOVING SHORTWAVE NOW LOCATED IN
NORTHERN IOWA...WHICH SHOULD KEEP THE NORTHWEST PART OF THE
FORECAST AREA DRY FOR A COUPLE MORE HOURS. HIGHER RESOLUTION MODEL
GUIDANCE SUGGESTS SOME ADDITIONAL SHOWERS SURGING NORTHEAST OUT OF
SOUTHERN MISSOURI AS A WEAK FRONTAL BOUNDARY PUSHES EAST. EARLIER
GRID UPDATES HAD INTRODUCED THIS TREND AND ONLY REQUIRED MINOR
UPDATES...MAINLY TO NUDGE TEMPERATURES DOWN A BIT.
&&
.SHORT TERM...(TODAY)
ISSUED AT 312 AM CDT SAT AUG 29 2015
07Z/2AM SURFACE ANALYSIS SHOWS A WEAK FRONTAL BOUNDARY EXTENDING
FROM WISCONSIN SOUTHWESTWARD TO THE TEXAS PANHANDLE. A PLUME OF
MAINLY MID-LEVEL MOISTURE AHEAD OF THE FRONT HAS RESULTED IN
SCATTERED LIGHT SHOWERS/SPRINKLES ACROSS THE WESTERN HALF OF THE
KILX CWA EARLY THIS MORNING. 00Z UPPER AIR SOUNDING SHOWED PLENTY
OF DRY AIR BELOW 850MB...SO PRECIP HAS BEEN HAVING A HARD TIME
REACHING THE GROUND IN MANY AREAS. FORECAST SOUNDINGS SHOW A
GRADUAL MOISTENING OF THE PROFILE TODAY...HOWEVER DEEP-LAYER
MOISTURE REMAINS LACKING. IN ADDITION...WIDESPREAD CLOUD COVER WILL
LIMIT INSTABILITY...WITH GFS SBCAPE VALUES ONLY REACHING THE 500 TO
1000J/KG RANGE. END RESULT WILL BE SCATTERED SHOWERS WITH PERHAPS A
RUMBLE OF THUNDER. THINK AREAL COVERAGE OF PRECIP WILL REMAIN
LOW...SO WILL ONLY CARRY 30-40 POPS. HIGH TEMPERATURES WILL RANGE
FROM THE UPPER 70S ALONG/NORTHWEST OF THE ILLINOIS RIVER...TO THE
MIDDLE 80S ALONG/SOUTHEAST OF I-70 WHERE CONDITIONS WILL REMAIN DRY
UNTIL A FEW SHOWERS ARRIVE DURING THE AFTERNOON.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 312 AM CDT SAT AUG 29 2015
FRONTAL BOUNDARY WILL SLOWLY PUSH EASTWARD LATER TODAY INTO
TONIGHT...WITH MODEL CONSENSUS SHOWING IT REACHING A CHICAGO TO
KIRKSVILLE LINE BY 12Z SUN. SCATTERED SHOWERS WILL BE ONGOING
AHEAD OF THE FRONT ACROSS MUCH OF THE AREA THIS EVENING...THEN
WILL SHIFT TO MAINLY LOCATIONS ALONG/EAST OF I-57 OVERNIGHT. MAIN
WEATHER CONCERN FOR TONIGHT WILL BE THE POTENTIAL FOR FOG ACROSS
THE W/NW CWA. AS THE SLOW-MOVING FRONT ARRIVES...WINDS WILL BECOME
LIGHT/VARIABLE ACROSS THIS AREA. DUE TO THE NEARLY CALM
WINDS...ADDED LOW-LEVEL MOISTURE FROM SHOWERS TODAY...AND PARTIAL
CLEARING LATE TONIGHT...THINK AT LEAST PATCHY FOG WILL FORM. BOTH
FORECAST SOUNDINGS AND NUMERIC GUIDANCE SUGGEST A REDUCTION IN
VSBY OVERNIGHT. CURRENT OBSERVATIONS IN THE VICINITY OF THE FRONT
ACROSS IOWA SHOW WIDESPREAD FOG...WITH A FEW VSBYS DOWN TO AROUND
1/4 MILE. THINK THIS SAME SCENARIO WILL UNFOLD FURTHER EAST
TONIGHT...SO HAVE INCLUDED PATCHY FOG IN THE FORECAST WEST OF I-55
AFTER MIDNIGHT.
THE FRONTAL BOUNDARY WILL SLOWLY DISSIPATE ON SUNDAY...HOWEVER
ENOUGH UPPER-LEVEL SUPPORT WILL PERSIST TO SUPPORT AT LEAST A
MENTION OF A FEW SHOWERS/THUNDERSTORMS. MOST MODELS PRODUCE LIGHT
QPF ACROSS NEARLY THE ENTIRE CWA AS THE BOUNDARY HAS SLOWED SLIGHTLY
FROM PREVIOUS RUNS. AS A RESULT...HAVE PULLED POPS FURTHER WEST TO
INCLUDE SLIGHT CHANCES AS FAR WEST AS THE ILLINOIS RIVER SUNDAY
AFTERNOON/EVENING.
AFTER THAT...THE REMAINDER OF THE EXTENDED LOOKS WARM AND DRY AS
UPPER-LEVEL RIDGING DOMINATES THE EASTERN CONUS THROUGH THE END OF
THE COMING WEEK. A SLIGHT WEAKNESS IN THE RIDGE APPEARS TO DEVELOP
ACROSS ILLINOIS INTO THE OHIO RIVER VALLEY...POTENTIALLY TRIGGERING
ISOLATED AFTERNOON/EVENING CONVECTION TUESDAY THROUGH FRIDAY.
HOWEVER...MID-LEVEL WARMING BENEATH THE RIDGE WILL LIKELY LEAD TO
CAPPING AND AN OVERALL SUPPRESSION OF CONVECTION. AS A
RESULT...WILL MAINTAIN A DRY FORECAST WITH HIGH TEMPERATURES
CLIMBING INTO THE UPPER 80S TO AROUND 90 DEGREES EACH DAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 635 AM CDT SAT AUG 29 2015
GENERALLY QUIET/VFR CONDITIONS EXPECTED ACROSS THE CENTRAL
ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME, DESPITE THE
PRESENCE OF A WEAK WEATHER DISTURBANCE AND SPOTTY
SHOWERS/THUNDERSTORMS. AT THIS POINT, EXPECT THE THUNDER COVERAGE
TO BE TOO SPARSE TO WARRANT A MENTION, AND WILL LIMIT SHOWERS TO
VCSH. THE ADDED LOW LEVEL MOISTURE FROM THE PRECIPITATION IN THE
AREA, AS WELL AS THE SLOW APPROACH OF A FRONTAL BOUNDARY
ASSOCIATED WITH DISTURBANCE, MAY RESULT IN FOG AND/OR STRATUS
DEVELOPMENT BY LATE TONIGHT. KPIA STANDS THE BEST CHANCE OF SEEING
A SIGNIFICANT CIG/VSBY REDUCTION LATER TONIGHT AS THE FRONTAL
BOUNDARY SHOULD BE CLOSEST TO THAT TERMINAL.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1037 AM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 1032 AM CDT SAT AUG 29 2015
Upstream 12Z raob at Omaha indicate a 500-700 ft stratus deck
advecting south and southeast towards northeast Kansas. Current
indications from the latest RAP and HRRR forecast soundings
suggest the low level saturation at 2500 ft to persist through
late afternoon so have adjusted to mostly cloudy skies through
most of the day. Also lowered highs about 5-7 degrees to the upper
70s and lower 80s. Will continue to monitor trends, especially
over north central areas where earlier clearing will quickly warm
temps.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 231 AM CDT SAT AUG 29 2015
Early this morning an upper level trough extended from the northern
Great Lakes...southwest across northern MO into eastern KS. The
surface cold front was moving southeast of the CWA. A broad upper
level ridge was located across the west central US.
The upper trough will shear apart with the more amplified northern
branch moving east across the Great Lakes States. The southern
section of the H5 trough will dig south across northeast OK through
the day. The model forecast soundings show wrap around low-level
moisture will advect southeast across northeast and east central KS
this morning. The low clouds should increase towards sunrise across
the eastern half of the CWA. I cannot rule out a few sprinkles but
the stronger ascent for rain showers and thunderstorms will be east
and south of the CWA. The clouds will gradually erode from west to
east across northeast and east central KS through the late morning
and early afternoon hours. Skies will remain clear across the
western counties of the CWA and patchy fog may develop before
sunrise but should mix out by 8 AM. Most areas will become mostly
sunny during the mid afternoon hours, though a few more clouds may
continue across the southeast counties through the afternoon hours.
Highs will be in the lower 80s across most of the CWA. The western
counties will receive more insolation and may reach into the mid 80s
for afternoon highs.
Tonight...The H5 trough digging south-southwest across east central
OK will cause a sfc and 850mb low to develop across central and
eastern OK. Some of the numerical models develop weak isentropic
lift across southeast KS and western MO. The extreme southeast
counties may see a few isolated showers but at this time I will keep
14 pops across the southeast counties of the CWA. Once again some
patchy fog may develop across north central KS by
sunrise...especially if skies remain clear through the night.
Overnight lows will drop to around 60 degrees across the western
counties of the CWA with lower to mid 60s across east central KS.
.LONG TERM...(Sunday THROUGH Friday)
ISSUED AT 231 AM CDT SAT AUG 29 2015
Remnants of upper trough moving through the area tonight will
weaken and leave a vort max in the vicinity of southern MO that
remains nearly stationary through Monday. This feature will
result in scattered clouds and a few showers that could extend
into extreme east central and southeast KS during this time. While
isolated showers aren`t out of the question in our far
southeastern forecast area south of I35, chances are low enough
that I did not include in any products at this time.
Other than the influence of the aforementioned vort max, an upper
ridge axis will extend from the southern Rockies into the Upper
Midwest early next week. From Tuesday through Wednesday, a
shortwave trough will move from the central Rockies to the Upper
Midwest, flattening the ridge axis and producing lift out ahead of
it. Main dynamics and lift with this system will be focused to
our north, but medium range models continue to have continuity in
producing QPF down into northeast KS with the best chance Tuesday
night.
After that, upper ridge builds back in which should keep the
eastern third of KS dry through the rest of the work week.
Pattern is favorable for temperatures to average several degrees
above normal for late August with highs near 90 for most of the
week and lows in the 65 to 70 degree range.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Sunday MORNING)
ISSUED AT 638 AM CDT SAT AUG 29 2015
MVFR ceilings are expected to move south to TOP/FOE within the hour,
while MHK is varying between VFR/MVFR. Expect MVFR ceilings to hold
on through the late morning before mixing out between 18-19Z. IFR
ceilings are seen by sites near the KS/NE boarder, but confidence
with them reaching this far south is low. After 18-19Z, light winds
and mostly clear skies are forecast the rest of the period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Bowen
SHORT TERM...Gargan
LONG TERM...GDP
AVIATION...Heller
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1115 AM EDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 1115 AM EDT SAT AUG 29 2015
14Z SFC ANALYSIS SHOWS HIGH PRESSURE RETREATING OFF TO THE EAST
WHILE A BROAD AREA OF LOW PRESSURE IS MOVING THROUGH THE PLAINS
STATES. UNDER PARTLY CLOUDY SKIES TEMPERATURES HAVE RISEN INTO THE
MID AND UPPER 70S FOR MOST OF THE CWA ALONG WITH INCREASES IN THE
DEWPOINTS TO THE MID AND UPPER 60S. MEANWHILE...WINDS ARE
RESPONDING TO THE EXIT OF THE HIGH TURNING TO THE SOUTH AND
SOUTHWEST AT 5 TO 10 KTS. THE DEPARTING HIGH HAS WORKED TO KEEP
THE WEATHER QUIET THROUGH KENTUCKY FOR MUCH OF THE PAST WEEK BUT
IS LOSING ITS HOLD ON THE AREA. AS SUCH...MOISTURE AND WARMTH WILL
BUILD THROUGH EASTERN KENTUCKY TODAY WITH A FEW POCKETS OF
CONVECTION POSSIBLE BY LATE AFTERNOON...MAINLY OVER WESTERN PARTS
OF THE CWA. THE LATEST HRRR IS ON BOARD WITH THIS...BUT ALSO
TRIES TO DEVELOP SOME OVER THE FAR SOUTHEAST...THAT SEEMS TOO
AGGRESSIVE SO WILL KEEP POPS SUB 14 PERCENT EAST OF INTERSTATE 75
THIS AFTERNOON. HAVE UPDATED THE GRIDS MAINLY TO ADD IN SOME OF
THE LATEST SHORTBLEND GUIDANCE ALONG WITH THE CURRENT OBS AND
TRENDS. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS
ALONG WITH AN UPDATED SET OF ZONES...DROPPING THE MENTION OF
MORNING FOG...TO FOLLOW.
UPDATE ISSUED AT 744 AM EDT SAT AUG 29 2015
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND SKY COVER
TO MATCH UP WITH THE LATEST TRENDS IN OBSERVATIONS...OTHERWISE THE
FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 336 AM EDT SAT AUG 29 2015
SURFACE HIGH PRESSURE HAS SHIFTED OFF TO THE EASTERN SEABOARD...
WITH SURFACE WINDS BECOMING MORE SOUTHEASTERLY ACROSS EASTERN
KENTUCKY. MOISTURE HAS BEEN ON THE INCREASE...WITH HIGHER BASED CU
DEVELOPING OVERNIGHT AND ADVECTING IN FROM THE SOUTHWEST.
TEMPERATURES ACROSS THE AREA RANGE FROM THE LOWER 60S IN THE
VALLEYS...TO THE UPPER 60S ON THE RIDGETOPS. ALOFT...A SHORT WAVE
TROUGH IS MOVING INTO THE GREAT LAKES/OHIO VALLEY REGION...WITHIN
A POSITIVELY TILTED TROUGH STRUNG OUT BACK TOWARDS THE OKLAHOMA
PANHANDLE. AN UPPER LEVEL LOW ALSO CONTINUES TO CHURN ACROSS GULF
COAST STATES.
MOISTURE WILL BE ON THE INCREASE TODAY AS THE TROUGH GRADUALLY
MOVES FURTHER EAST. HAVE MAINTAINED SLIGHT CHANCE POPS IN THE
WEST...WHERE THERE IS A BETTER CHANCE OF BREAKING THE CAP. FURTHER
EAST...IT APPEARS THE CAP WILL BE STRONG ENOUGH TO KEEP MOST
CONVECTION AT BAY...BESIDES A STRAY SHOWER OR STORM. HIGHS TODAY
WILL TOP OUT IN THE MID 80S...GENERALLY A FEW DEGREES WARMER
COMPARED TO YESTERDAY.
THE TROUGH WILL CONTINUE TO DAMPEN AS IT HEADS ACROSS THE OHIO
AND TENNESSEE VALLEYS THROUGH SUNDAY...HOWEVER THE GULF COAST
UPPER LEVEL WILL ALSO GET PULLED NORTH...HELPING TO REINFORCE AT
LEAST A WEAKER CAP ENVIRONMENT. AS SUCH...EXPECT MORE SCATTERED
CONVECTIVE COVERAGE ON SUNDAY. THICKER CLOUDS WILL KEEP THE HIGHS
CONFINED TO THE LOWER 80S FOR MOST LOCATIONS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 356 AM EDT SAT AUG 29 2015
THE UPPER LEVEL PATTERN OVER THE OHIO VALLEY THROUGH THE EXTENDED
WILL FEATURE A WEAKENING AND SHIFTING UPPER LEVEL RIDGE. IT WILL
SHIFT TOWARDS THE EAST AND FURTHER NORTH AS IT SETS UP OVER THE
UPPER GREAT LAKES AND INTO THE NEW ENGLAND REGION AND REMAINS IN
PLACE THROUGH THE ENTIRE EXTENDED. DURING THIS TIME...UNDERNEATH
THE RIDGE...A FEW LOW CENTERS...INCLUDING THE REMNANTS OF TS ERIKA
WILL DRIVE MUCH OF EASTERN KENTUCKYS WEATHER CUT OFF FROM THE MAIN
UPPER LEVEL FLOW. DURING THIS TIME...MUCH OF THE ACTIVITY REMAINS
OVER THE SOUTH CENTRAL AND SOUTHEASTERN CONUS WITH AN INFLUX
SOUTHERLY MOIST FLOW CONTINUING THROUGH THE PERIOD AS WELL. PIN
POINTING THESE FEATURES IN THIS WEAK FLOW WILL PROVE VERY
DIFFICULT.
CLOSER TO THE SURFACE...WITH THE PATTERN DRIVEN BY SEVERAL WEAK
LOW CENTERS...SOUTHERLY MOIST AND UNSTABLE FLOW AND WEAK UPPER
LEVEL FLOW...WOULD EXPECT A DIURNAL TREND TO THE SHOWER AND
THUNDERSTORM CHANCES FOR THE EXTENDED. THIS THOUGHT PROCESS IS
SUPPORTED BY THE SHEAR LACK OF ANY FORCING. HOWEVER...MODEL
SOUNDINGS WOULD ALSO SUGGEST WITH THE LACK OF ANY GOOD CAP AS
WELL. WITH THIS IN MIND...IT IS QUITE DIFFICULT TO PIN POINT A DRY
AFTERNOON TO THE EXTENDED AS WELL. DID GO BELOW THE SUPER BLEND IN
MOST DAYS KEEPING SLIGHT CHANCE TO VERY LOW CHANCE POPS THROUGH
THE PERIOD AND NIXING ANY NOCTURNAL PRECIP. IN SHORT...THE VERY
WARM...MUGGY...AND UNSTABLE DAYS OF SUMMER ARE RETURNING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 744 AM EDT SAT AUG 29 2015
MVFR OR WORSE FOG WILL BURN OFF BY AROUND 13Z...THEN EXPECT VFR
CONDITIONS TO PREVAIL THEREAFTER. SOME ISOLATED CONVECTION WILL
THREATEN DURING THE DAY...HOWEVER WILL CONTINUE TO LEAVE OUT A
MENTION AT THE TAF SITES FOR NOW GIVEN THE EXPECTED LIMITED AREAL
COVERAGE. WINDS WILL ENGAGE OUT OF THE SSW AT AROUND 5 KTS DURING
THE DAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...SHALLENBERGER
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
629 AM EDT SAT AUG 29 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (NOW THROUGH SUNDAY)...
ISSUED AT 235 AM EDT SAT AUG 29 2015
EARLY MORNING WATER VAPOR IMAGERY COMBINED WITH 500 MB HEIGHTS
SHOWED A MID LEVEL TROUGH EXTENDING FROM THE CENTRAL PLAINS
NORTHEASTWARD TOWARD EASTERN WISCONSIN...WHILE A BROAD CLOSED LOW
WAS ADVANCING NORTHWARD FROM THE GULF INTO THE DEEP SOUTH. THE LOWER
OHIO VALLEY LIED IN BETWEEN...AS OBSERVED BY IR SATELLITE IMAGERY
WHICH SHOWED MOSTLY CLEAR SKIES AND LIGHT WINDS. DEEPER
MOISTURE...CLOUDY SKIES...AND LIGHT RADAR RETURNS WERE OFF TO THE
NORTHWEST.
THE MAIN FORECAST CONCERN FOR TODAY IS PRECIPITATION CHANCES AS THE
TWO AFOREMENTIONED SYSTEMS TRACK TOWARD EACH OTHER. THE SOUTHERN
SYSTEM WILL DRAW MORE MOISTURE INTO THE AREA...CHARACTERIZED BY
DEWPOINTS APPROACHING THE UPPER 60S TO NEAR 70 THIS AFTERNOON. THE
NORTHERN SYSTEM WILL BEGIN TO WASH OUT AS IT SLOWLY ADVANCES
EASTWARD. OVERALL...DYNAMICS ARE RATHER WEAK WITH THESE SYSTEMS BUT
A WEAKLY OR UNCAPPED ENVIRONMENT ALONG WITH PEAK HEATING GENERATING
POCKETS OF INSTABILITY SHOULD BREAK OUT ISOLATED TO SCATTERED NON
SEVERE SHOWERS AND STORMS.
NEAR TERM HI-RES MODELS SHOW HIGH AGREEMENT SPATIALLY...TEMPORALLY
AND RUN TO RUN WHICH LEADS TO A HIGHER CONFIDENCE FORECAST FOR
TODAY. THE HRRR HAS BEEN VERY CONSISTENT SHOWING ISOLATED
SHOWERS/STORMS BREAKING OUT DURING THE EARLY AFTERNOON HOURS AS
CONVECTIVE TEMPS ARE REACHED. THE NSSL AND SPC WRF SOLUTIONS OFFER
SIMILAR SOLUTIONS AS WELL. THE HIGHEST COVERAGE LOOKS TO BE ALONG A
BOWLING GREEN TO FRANKFORT LINE AND WESTWARD...ALONG THE AXIS OF
GREATER INSTABILITY AND MOISTURE.
MOSTLY SUNNY SKIES THIS MORNING WILL BE REPLACED BY SCATTERED
CUMULUS AS WELL AS MID/HIGH CLOUDS...WHICH SHOULD MAKE FOR A PARTLY
TO MOSTLY CLOUDY AFTERNOON AT TIMES. PLAN ON HIGHS TO TOP OUT IN THE
MID TO UPPER 80S. THE INCREASE IN DEWPOINTS WILL MAKE IT FEEL
SLIGHTLY MORE MUGGY THAN RECENT DAYS.
EXPECTING A DROP OFF IN PRECIPITATION THIS EVENING WITH THE LOSS OF
HEATING...THOUGH WILL STILL CARRY A CHANCE THROUGH THE OVERNIGHT
WITH THE WEAK TROUGH OVERHEAD. SUNDAY STILL LOOKS TO BE THE BETTER
DAY FOR PRECIPITATION AS WE`LL HAVE A MORE FAVORABLE ENVIRONMENT AND
OVERALL DYNAMICS. PRECIPITATION COVERAGE STILL LOOKS TO BE
SCATTERED...SO KEPT CHANCES IN THE 30-40 PERCENT RANGE.
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
ISSUED AT 300 AM EDT SAT AUG 29 2015
MONDAY - WEDNESDAY...
A WEAK UPPER LOW NEAR THE OHIO VALLEY MAY PROVIDE ENOUGH SUPPORT FOR
ISLD SHOWERS/STORMS MAINLY ALONG AND EAST OF I-65 SUNDAY NIGHT AND
MONDAY. THE GFS IS MOST OPTIMISTIC WITH THIS CONVECTION AND EVEN
THIS NOTORIOUSLY WET MODEL ISN`T SHOWING MUCH PRECIP.
TUESDAY LOOKS TO BE DRY WITH THE NEXT CHANCE FOR SHOWERS/STORMS
ARRIVING FOR WED. MID RANGE MODELS ARE DIFFERENT IN DEPICTING THE
MAIN SOURCE FOR FORCING/MOISTURE. THE GFS INDICATES THE REMNANTS OF
T.S. ERIKA WILL BE THE CAUSE WHILE THE ECMWF SUGGESTS A NORTHERN
STREAM TROUGH WILL BE THE CAUSE. EITHER WAY WILL CARRY 20-30% POPS
FOR WED.
TEMPS FOR EARLY TO MID WEEK WILL BE ON THE INCREASE BACK TO SEASONAL
NORMS WITH HIGHS RANGING MAINLY THE MID TO UPPER 80S WITH A FEW
LOCATIONS NEAR 90 TUES/WED.
THURSDAY - FRIDAY...
LONG RANGE MODELS AGREE THAT A STRONG UPPER RIDGE AXIS WILL BUILD
INTO PORTIONS OF THE PLAINS/MIDWEST. THICKNESSES WILL INCREASE OVER
THE OHIO VALLEY AS A RESULT BRINGING TEMPS SLIGHTLY ABOVE NORMAL FOR
THE LATTER HALF OF THE WEEK (UPPER 80S/LOWER 90S FOR HIGHS).
ALTHOUGH A CLEAR TRIGGER IS NOT APPARENT, SOME LONG RANGE SIGNALS
SUGGEST A DIRTY RIDGE WITH SUBTLE WAVES MAY CAUSE MAINLY DIURNAL
CONVECTION PEAKING DURING THE AFTERNOON/EVENING HOURS BOTH
THURS/FRI. THUS WILL HAVE LOW POPS BOTH OF THESE DAYS.
&&
.AVIATION (12Z TAF UPDATE)...
ISSUED AT 629 AM EDT SAT AUG 29 2015
BROKEN HIGH CLOUDS WILL OVERSPREAD TAF SITES THIS MORNING...AND LOOK
FOR SOUTHERLY WINDS TO DEVELOP. WITH A WEAKLY UNSTABLE AIR MASS AND
A COUPLE WEATHER SYSTEMS NEARBY...THERE WILL BE A SLIGHT CHANCE OF A
SHOWER/STORM FROM EARLY AFTERNOON THROUGH THE END OF THE TAF PERIOD.
HOWEVER COVERAGE IS NOT EXPECTED TO BE VERY HIGH SO WILL CONTINUE TO
LEAVE OUT OF TAF. MOSTLY CLOUDY SKIES SHOULD LMIIT
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........ZBT
LONG TERM.........AMS
AVIATION..........ZBT
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
820 AM MDT SAT AUG 29 2015
.UPDATE...
WE HAVE ADDED ISOLATED SHOWERS TO THE GARDINER...LIVINGSTON...AND
HARLOWTON AREAS THIS MORNING...AND ISOLATED SHOWERS AND STORMS TO
THOSE SAME AREAS THIS AFTERNOON. THAT MOVE IS BASED ON THE RECENT
TRENDS IN UPSTREAM RADAR IMAGERY AND RECENT HRRR SIMULATIONS. THE
REST OF THE FORECAST LOOKS LARGELY ON TRACK IN ADVERTISING A HOT
DAY EVERYWHERE WITH CRITICAL FIRE WEATHER CONDITIONS ACROSS SOUTH
CENTRAL MT AS SOUTHWEST WINDS INCREASE BY AFTERNOON. SCHULTZ
&&
.SHORT TERM...VALID FOR TDY AND SUN...
HOT AND DRY CONDITIONS WILL PREVAIL TODAY BEFORE SLIGHTLY COOLER
AIR ARRIVES FOR THE DAY SUNDAY. AN UPPER LOW AND TROUGH WILL MOVE
ONTO THE PACIFIC NORTHWEST COAST THIS AFTERNOON RESULTING IN A
SOUTHWEST FLOW ALOFT ACROSS OUR FORECAST AREA. THE BULK OF THE
ENERGY WITH THE SYSTEM WILL REMAIN ACROSS THE PACIFIC NORTHWEST
INTO SOUTHWEST CANADA. A WEAK COLD FRONT WILL MOVE ACROSS OUR FAR
WESTERN ZONES BY EARLY EVENING AND ACROSS THE REMAINING PORTIONS
OF OUR FORECAST AREA OVERNIGHT. THERE WILL BE A SLIGHT CHANCE FOR
A SHOWER OR THUNDERSTORM ALONG THE FRONT THIS EVENING FROM ABOUT
BILLINGS WESTWARD WITH ISOLATED CHANCES SPREADING EAST AFTER
MIDNIGHT.
GUSTY SOUTHWEST WINDS AND HOT TEMPERATURES AHEAD OF THE FRONT
WILL MAKE FOR DANGEROUS FIRE CONDITIONS FROM ABOUT YELLOWSTONE
COUNTY WESTWARD WHERE A RED FLAG WARNING IS IN PLACE THIS
AFTERNOON AND EVENING. FURTHER EAST WINDS ARE NOT EXPECTED TO BE
AS GUSTY BUT WE WILL STILL NEED TO WATCH OUR EAST AS IT WILL BE
MARGINAL. TEMPERATURES WILL BE HOT TODAY WITH NEAR RECORD HIGHS
FOR BILLINGS AND MILES CITY. THE RECORD FOR MILES CITY TODAY IS
101 WITH THE BILLINGS RECORD AT 97 DEGREES.
THE PACIFIC NORTHWEST SYSTEM WILL SHIFT EAST SUNDAY BRINGING AN
AREA OF VORTICITY ACROSS THE STATE. THIS WILL RESULT IN THE
POSSIBILITY OF AN ISOLATED SHOWER OR THUNDERSTORM ACROSS THE
ENTIRE FORECAST AREA. THE SYSTEM WILL SWEEP A STRONGER COLD FRONT
ACROSS THE AREA SUNDAY NIGHT USHERING IN MUCH COOLER TEMPERATURES
FOR MONDAY AS READINGS WILL BE BACK DOWN TO AROUND NORMAL FOR THIS
TIME OF YEAR. HOOLEY
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
POST FRONTAL ZONAL FLOW ON MONDAY WITH COOLER TEMPERATURES BEFORE
BACKING FLOW ON TUESDAY BRINGS A WEAK DOWNSLOPE PATTERN WITH
WARMER TEMPERATURES. THE UPSTREAM TROUGH DRIVING THE BACKING IN
THE FLOW ALOFT STAYS OVER THE PACIFIC NORTHWEST FOR THE REST OF
THE WEEK BUT UNDERGOES FLUCTUATIONS IN ITS DEPTH AND LOCATION AS
ENERGY FLOWS THROUGH THE TROUGH. ONE OF THESE FLUCTUATIONS ON
WEDNESDAY PUSHES THE LEESIDE TROUGH FURTHER EAST AND A WEAK
SURFACE LOW FORMS OVER WESTERN SOUTH DAKOTA. MODELS DIFFER WHETHER
THIS INDUCES A LIGHTER SOUTHWEST SURFACE FLOW OR A WEAK EASTERLY
FLOW SO WILL HAVE TO WATCH FOR HOW CAPPED TEMPERATURES MAY BE ON
WEDNESDAY. SMOKE WILL CONTINUE TO FILTER SUNLIGHT AS THE FLOW
PATTERN SHOULD ADVECT SMOKE FROM CENTRAL IDAHO AND NORTHERN
CALIFORNIA OVER THE AREA BUT MAY NOT BE QUITE AS DENSE AS THIS
PAST WEEK.
AS THE TROUGH DEEPENS OVER THE PACIFIC NORTHWEST ON THURSDAY THE
EJECTING ENERGY TRAVELS A BIT FURTHER SOUTH WHICH MIGRATES THE
SURFACE LOW INTO SOUTHEAST MONTANA. THIS DEEPER EASTERLY FLOW
DEVELOPS A STRONG CAP WHICH DOES PUT A LID ON TEMPERATURES SO
EXPECTING HIGHS TO BE BELOW 80 TOWARDS THE END OF THE WEEK. BORSUM
&&
.AVIATION...
THICK SMOKE WILL CONTINUE TO IMPACT THE AREA TODAY...WITH THE
BIGGEST IMPACTS OVER SOUTHEAST MONTANA. OCCASIONAL MVFR CONDITIONS
CAN BE EXPECTED FROM MILES CITY TO BAKER. AS THE WINDS ALOFT TURN
MORE SOUTHWEST THROUGH THE DAY...CONDITIONS SHOULD IMPROVE THIS
AFTERNOON AND EVENING. A FEW SHOWERS HAVE BEEN ADDED FROM
HARLOWTON TO BIG TIMBER TO LIVINGSTON THIS MORNING. CONTINUED THE
SLIGHT CHANCE OF SHOWERS AND ADDED A SLIGHT CHANCE OF
THUNDERSTORMS IN THESE SAME LOCATIONS THIS AFTERNOON AND EVENING.
THIS ACTIVITY COULD GENERATE STRONG WIND GUSTS. SOUTHWEST WINDS
WILL INCREASE THIS AFTERNOON AROUND LIVINGSTON WITH SOME GUSTS TO
30KTS. MOUNTAINS WILL BE MOSTLY OBSCURED THROUGH THE DAY. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 096 067/087 052/081 054/087 057/083 053/077 049/075
0/K 22/T 20/U 01/U 11/B 11/B 11/B
LVM 092 060/085 045/079 047/084 049/080 045/074 041/074
2/T 22/T 20/N 00/U 11/B 22/T 22/T
HDN 099 064/089 053/083 053/091 056/087 052/081 049/079
0/K 22/T 20/U 01/U 11/B 11/B 11/B
MLS 101 066/093 059/082 057/091 059/088 055/083 051/080
0/G 02/T 20/U 00/U 11/U 11/B 11/B
4BQ 099 062/093 057/081 056/091 059/089 056/085 053/079
0/K 02/T 20/U 00/U 11/U 11/U 11/B
BHK 098 062/095 055/081 056/091 057/089 054/085 052/079
0/K 02/T 30/N 00/U 11/U 11/U 11/B
SHR 097 058/092 050/082 049/090 053/087 049/082 047/078
0/K 12/T 20/U 01/U 11/B 11/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 9 PM MDT THIS
EVENING FOR ZONES 28-29-34-35-39>42-56-63>68.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
532 AM MDT SAT AUG 29 2015
.AVIATION...
12Z TAF CYCLE
LIFR VSBYS IN FG WILL CONTINUE ACROSS THE MORENO VALLEY IN THE
VICINITY OF KAXX THRU APPROX 14Z. LATER TODAY...HI-RES MODELS
SHOWING THAT A SHRA OR TSRA WILL BE POSSIBLE JUST ABOUT
ANYWHERE...THOUGH FAVORED AREAS WILL BE ACROSS THE HIGH TERRAIN.
STORM MOTION WILL VARY...BUT WILL REMAIN LIGHT. BRIEF MVFR CIGS
ARE POSSIBLE IN HEAVY RAIN...ESPECIALLY ACROSS THE SOUTHWEST
MOUNTAINS. CONVECTION SHOULD GENERALLY DIMINISH BY 06Z.
34
&&
.PREV DISCUSSION...341 AM MDT SAT AUG 29 2015...
.SYNOPSIS...
STORM COVERAGE WILL LOWER SLIGHTLY TODAY ALTHOUGH LOCALLY HEAVY
RAIN WILL REMAIN POSSIBLE OVER THE MOUNTAINS...ESPECIALLY
SOUTHWEST AND NORTHERN SACRAMENTOS. THE FAVORED STORM COVERAGE
AREAS WILL SHIFT WESTWARD AND FAVOR THE CONTINENTAL DIVIDE TO THE
ARIZONA BORDER ON SUNDAY. A PACIFIC TROUGH WILL NUDGE CLOSER TO
THE STATE ON MONDAY AND SHIFT THE MAIN STORM COVERAGE FURTHER
EAST. LOCALLY HEAVY RAIN WILL REMAIN POSSIBLE SUNDAY/MONDAY. THE
MONSOON MOISTURE PLUME...ALBEIT DISJOINTED AT TIMES... WILL REMAIN
OVER PORTIONS OF THE STATE THROUGH THE REST OF THE WEEK. A MORE
CONCENTRATED MOISTURE PLUME WILL BE POSSIBLE NEXT WEEKEND AS A
PACIFIC TROUGH STRENGTHENS AND DEEPENS TO THE WEST OF THE STATE.
&&
.DISCUSSION...
MASSAGED POPS/SKY COVER AND WEATHER HERE AND THERE BUT NO MAJOR
CHANGES. THE OVERALL WEATHER THEME APPEARS TO BE SIMILAR. A LITTLE
LESS STORM COVERAGE WITH THE FOCUS GRADUALLY SHIFTING WESTWARD
TODAY. THE MAIN FOCUS ON SUNDAY STILL APPEARS TO BE ACROSS THE
WESTERN THIRD AND CURRENT POPS REFLECT THAT. THE PACIFIC TROUGH
WILL NUDGE CLOSER TO THE STATE ON MONDAY THUS SHIFTING THE MAIN
MOISTURE PLUME A LITTLE FURTHER EAST. IT APPEARS THAT THE PAC
TROUGH WOULD REFORM OR DEEPEN TO THE WEST TUESDAY AND CONTINUE
INTO NEXT WEEKEND. THIS WOULD PLACE THE MAIN MONSOONAL MOISTURE
PLUME OVER SOME PORTION OF THE STATE DURING THIS PERIOD. THUS AN
ACTIVE PERIOD BUT NOTHING OUT OF THE ORDINARY AT THIS TIME. WILL
BE FOLLOWING THE UPPER HIGH PROGRESSION BECAUSE ONCE IT
CONSOLIDATES/LESS HIGH CENTERS/ AND MOVES EAST OF THE STATE THEN A
JUICIER MOISTURE FLOW SHOULD ENSUE. THAT APPEARS POSSIBLE LATE
WEEKEND OR DURING NEXT WEEKEND.
SOME MODEL DISPCREPANCIES FOR TODAYS POP FORECAST. HRRR IS MUCH
MORE BULLISH ACROSS THE EASTERN PLAINS COMPARED TO THE NAM/GFS.
LATEST WATER VAPOR IMAGERY SHOWS A DRIER AND MORE STABLE AIRMASS
POISED TO THE NORTH OF THE STATE SO WOULD EXPECT SOME OF THIS AIR
TO MAKE IT INTO EASTERN NM AS THE DAY PROGRESSES. DESPITE THIS
IMPACT...DECIDED TO BEEF UP POPS A BIT MORE ACROSS THE EC/SE
PLAINS THANKS TO THE LATEST HRRR FORECAST. EITHER WAY...MAIN FOCUS
WILL BE SHIFTING SLIGHTLY MORE TO THE WEST. STEERING FLOW FOR THE
STORMS APPEARS TO BE PRETTY LIGHT DUE TO THE CLOSE PROXIMITY TO
THE HIGH CENTER. ONE NOTABLE STEERING FLOW DIRECTION WOULD BE THE
NE FLOW ORIGINATING FROM THE SANDIA MTNS. THIS FLOW USUALLY BODES
WELL FOR PORTIONS OF THE ABQ NE HEIGHTS SO FOOTHILL RECREATIONALISTS
SHOULD BE COGNIZANT OF THAT POTENTIAL IMPACT. ALSO BEEFED UP QPF
AND POPS ACROSS THE GILA REGION AND NORTHERN SACRAMENTO MTNS.
SINCE THE CELLS SHOULD TRAVEL SOUTHWARD OVER THE SACS...RESIDENCE
TIME MAY NOT BE ALL THAT MUCH...BUT SOMETHING TO WATCH IN TERMS
OF LOCALIZED FLOODING. LOCALIZED FLOODING ALSO POSSIBLE ACROSS
THE GILA REGION. BASED ON THE LATEST NASASPORT SOIL MOISTURE
IMAGERY...CATRON COUNTY APPEARS TO BE RATHER MOIST AS WELL AS
PORTIONS OF THE CENTRAL MTNS/EAST SLOPES.
NOT A LOT OF SIGNIFICANT CHANGES IN THE LATEST MODELING. THE
INITIAL PAC TROUGH IS EXPECTED TO SHEAR OUT ACROSS THE
NORTHERN/CENTRAL ROCKIES/NORTHERN PLAINS SUNDAY/MONDAY. LOCALLY
HEAVY RAIN AND A DIFFUSE MONSOONAL MOISTURE PLUME WILL FAVOR THE
CONTINENTAL DIVIDE WESTWARD SUNDAY. THEN SHIFT A BIT MORE TO THE
EAST ON MONDAY BASED ON THE INITIAL PAC TROUGH EJECTION.
THE PAC TROUGH WILL DEEPEN TO THE WEST OF THE STATE TUESDAY
THROUGH THE END OF THE WEEK. PRETTY TYPICAL PATTERN FOR
SEPTEMBER...AT LEAST BASED ON THE PAST FEW YEARS. MONSOONAL
MOISTURE WILL TRY TO MOVE NORTHWARD AHEAD OF THE TROUGH AND
CONTINUE SH/TS OVER THE FORECAST AREA. SUBTLE DAY TO DAY CHANGES
WILL DEPEND ON WEAK VORTICE WAVES ORIGINATING FROM MEXICO AS WELL
AS A DRIER AND MORE STABLE AIRMASS ROTATING AROUND THE HIGH
CENTER. IT APPEARS THAT BASED ON THE PAC TROUGH PROGRESSION...THE
UPPER HIGH WOULD EVENTUALLY SHIFT EAST OF THE STATE ALTHOUGH THIS
PROGRESSION WILL MOST LIKELY JUMP AROUND A BIT BECAUSE THE MODELS
HAVE BEEN HAVING A HARDER TIME WITH THE PROGRESSION OF THE PAC
TROUGH ALONG THE WEST COAST. EITHER WAY...WOULD EXPECT THE
MONSOONAL MOISTURE PLUME...ORIGINATING FROM MEXICO...TO BECOME
MORE CONSOLIDATED AROUND THE UPPER HIGH OR BECOMING LESS DIFFUSE.
WILL JUST HAVE TO WAIT ON SEE ON THAT ONE. DECIDED TO INCREASE
TEMPS SLIGHTLY ABOVE MODEL GUIDANCE OR SUPER BLEND LEVELS DURING
THE EXTENDED PERIOD. ALSO LOWERED MIN TEMPS IN THE HIGHER MTN
BASINS SUCH AS THE MORENO VALLEY DUE TO LOWERING DEWPOINTS.
50
&&
.FIRE WEATHER...
BACK DOOR FRONT HAS PUSHED WESTWARD TO THE CONTDVD EARLY THIS
MORNING. THIS WILL SET THE STAGE FOR MORE ACTIVITY ACROSS WESTERN NM
TODAY AS COMPARED TO YESTERDAY...THOUGH WETTING RAINS WILL STILL BE
SPOTTY...WITH THE WEST CENTRAL HIGHLANDS BEING THE EXCEPTION. HI-RES
MODELS STILL SHOWING A FAIR AMOUNT OF ACTIVITY ACROSS THE EASTERN
PLAINS AS WELL...BUT WITH DRIER AIR MOVING IN...IT SHOULD NOT BE AS
WIDESPREAD OR AS ORGANIZED AS YESTERDAY. STORM MOTION LOOKS TO SHIFT
A BIT TODAY...PERHAPS MORE TOWARD THE SOUTHWEST OR WEST ACROSS THE
EAST AND MORE TOWARD THE NORTH ACROSS THE WEST.
THE UPPER HIGH IS STILL ON TRACK TO ELONGATE FROM SW TO NE FROM SE
AZ TO NE NM ON SUNDAY. MEANWHILE...THE CENTROID OF THE MID LEVEL
HIGH WILL SHIFT OVER EASTERN NM OR WEST TEXAS. THIS WILL ALLOW MID
LEVEL MOISTURE TO STREAM NORTHWARD ACROSS FAR WESTERN NM AND EASTERN
AZ. APPEARS THAT THE BEST PRECIP CHANCES WILL BE ACROSS THE WESTERN
THIRD OF THE STATE AND SOME SPOTTY HEAVY RAINFALL WILL BE POSSIBLE.
STORM MOTION WILL GENERALLY BE TOWARD THE NORTHEAST AROUND 5-10 MPH.
THE MOISTURE PLUME STILL LOOKS TO SHIFT EASTWARD ON MONDAY...
FOCUSING THE BEST CHANCE FOR TSTMS FROM THE WEST CENTRAL HIGHLANDS
NEWD TO THE NE PLAINS. STORM MOTION WILL LIKELY BE A BIT MORE
ERRATIC...BUT GENERALLY FROM WEST TO EAST OR SW TO NE.
APPEARS THAT THE MOISTURE PLUME WILL STILL BE HOVERING OVER NM ON
TUESDAY...THOUGH NOT AS ROBUST AS SUNDAY OR MONDAY. WILL STILL LOOK
FOR STORMS...MAINLY OVER THE HIGH TERRAIN.
ECMWF AND CANADIAN MODELS CONTINUE TO SHOW THE UPPER HIGH CENTERED
FARTHER SOUTH WEDNESDAY...ALLOWING FOR DRIER WESTERLY FLOW ACROSS
NORTHERN NM. THE GFS HANGS ONTO A DISORGANIZED PLUME ON WEDNESDAY
WITH THE HIGH OVER WEST TEXAS...THOUGH BY THURSDAY...THE HIGH
WEAKENS ALLOWING THAT DRIER AIR INTO NORTHERN NM. WITH MODEL
INCONSISTENCIES OF LATE...HARD TO HAVE A DEFINITE ANSWER...BUT IT
DOES LOOK LIKE MODELS ARE TRENDING TOWARD A DRIER LATTER HALF OF
NEXT WEEK.
VERY LITTLE TEMPERATURE CHANGES OVER THE NEXT SEVERAL DAYS... WITH
HIGHS GENERALLY AT OR ABOVE NORMAL. HUMIDITIES WILL LOWER WED/THURS
MAINLY ACROSS NORTHERN NM IF THE AFOREMENTIONED PATTERN COMES TO
FRUITION. WEAK TRANSPORT WINDS WILL CONTINUE TO RESULT IN POOR TO
FAIR VENT RATES ACROSS NORTH CENTRAL NM TODAY...BUT SHOULD GENERALLY
IMPROVE INTO THE GOOD TO EXCELLENT RANGE NEXT WEEK. ONE EXCEPTION
MAY BE ACROSS THE SANGRE DE CRISTO MOUNTAINS ON MONDAY.
34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1026 AM EDT SAT AUG 29 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE MID-ATLANTIC REGION WILL BRING FAIR
WEATHER THROUGH TODAY. INCREASING MOISTURE FROM THE GULF OF
MEXICO COULD BRING SHOWERS AND ISOLATED THUNDERSTORMS TO THE
AREA SUNDAY INTO MONDAY. ERIKA...OR THE REMNANTS OF ERIKA...WILL
APPROACH FLORIDA EARLY NEXT WEEK...POSSIBLY TRACKING INTO THE
NORTHERN GULF OF MEXICO AFTERWARD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...A RATHER NICE SATURDAY FORECAST AS LONG AS
ONE DOESN`T MIND THE SUNLIGHT BEING INCREASINGLY FILTERED BY A
GROWING CANOPY OF CIRRUS. THE DEWPOINT HAS CREPT UP FROM YESTERDAY
AND THE HRRR HAD BEEN SUGGESTING THAT A FEW SHOWERS MATERIALIZE OVER
FAR SOUTHERN COUNTIES. SUCCESSIVE RUNS HAVE BACKED OFF ON THIS SO
WILL KEEP THE FORECAST DRY AT THIS TIME-ANYTHING THAT FALLS SHOULD
BE NON-MEASUREABLE SPRINKLES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...HIGH PRESSURE WILL BASICALLY DISSIPATE
ACROSS THE AREA SUNDAY AS MID LEVEL LOW PRESSURE...CURRENTLY OVER
THE GULF COAST RAMBLES INTO THE UPSTATE SOUTH CAROLINA REGION.
THIS FEATURE COMBINED WITH THE ANTICYCLONIC FLOW AROUND THE
BERMUDA RIDGE WILL ADVECT MOISTURE LADEN AIR INTO THE REGION. SOME
DIFLUENCE IS ALSO NOTED IN THE AREA. AS PRECIPITABLE WATERS RISE
TO ALMOST TWO INCHES...LOW CHANCE POPS ARE IN THE PICTURE MAINLY
ACROSS SOUTH CAROLINA SUNDAY AND AREA WIDE MONDAY. TEMPERATURES
ARE MOSTLY SEASONABLE WITH HIGHS IN THE MID TO UPPER 80S AND LOWS
IN THE LOWER TO MIDDLE 70S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...EXPECT A DIFFUSE MID LEVEL PATTERN DURING THE
EXTENDED PERIOD WITH A SIMILAR PRESSURE PATTERN. OVERALL THE AREA
REMAINS BETWEEN ATLANTIC RIDGING AND HIGH PRESSURE OUT WEST. WHAT
EVENTUALLY REMAINS OF TROPICAL STORM ERIKA MEANDERS AROUND THE
SOUTHEAST AS A VORT CENTER SEEMINGLY NEVER GOING ANYWHERE. THERMAL
PROFILES REMAIN MOIST HOWEVER AND WITH THE USUAL MESOSCALE
FEATURES...DECENT CHANCE POPS ARE IN THE FORECAST EACH DAY. NO
CHANGES TO THE TEMPERATURE FORECAST WITH READINGS NEAR NORMAL FOR
DAYTIME HIGHS AND SLIGHTLY ABOVE FOR OVERNIGHT LOWS.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...HIGH PRESSURE WILL STAY IN CONTROL FOR THE NEXT
24 HOURS WITH HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE
FORECAST PERIOD. A BROAD AREA OF LOW PRESSURE CENTERED OVER THE
ALABAMA/MISSISSIPPI BORDER WILL TRY TO BRING UP MOISTURE FROM
THE SOUTH...BUT IT WILL LIKELY NOT MAKE IT FAR ENOUGH NORTHWARD
TO GIVE US ANY WEATHER. LOOK FOR PREDOMINATELY NORTHEAST FLOW
TODAY.
EXTENDED OUTLOOK...PREDOMINATELY VFR WITH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. BRIEF MORNING
FOG/STRATUS IS ALSO EXPECTED EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SATURDAY...STILL RATHER
CHOPPY AND WILL LEAVE SCEC AS-IS IN THE CONTINUED MODERATE
NORTHEASTERLY GRADIENT. NO CHANGES TO THE FORECAST AND THE PREVIOUS
DISCUSSION FOLLOWS.
AS OF 630 AM SATURDAY...HAVE RAISED A SMALL CRAFT EXERCISE
CAUTION FLAG FOR ALL WATERS...EXCEPT BETWEEN LITTLE RIVER INLET TO
MURRELLS INLET WHERE ITS SOMEWHAT PROTECTED FROM THE HIGHER NE
WIND WAVES DUE TO THE LOWER FETCH FOR THEM TO GROW.
THE MODEST 1020+ HIGH BROADLY CENTERED FROM OVER THE NC-VA BORDER
TO ACROSS THE MID-ATLANTIC STATES...IS PROGGED TO REMAIN
RELATIVELY IN PLACE THRU THIS NEAR TERM PERIOD. AT THIS SAME
TIME...A WEAK SFC LOW IS PROGGED BY THE MODELS ALONG A STALLED SFC
BOUNDARY ORIENTED NE-SW OFF THE CAROLINA COASTLINES THIS
MORNING...THAT WILL TRACK NE ALONG THIS STALLED FRONT TO A
POSITION OFF CAPE HATTERAS BY DAYBREAK SUNDAY. THE AREA WATERS IS
ALREADY EXPERIENCING A TIGHTENED SFC PG ATTM...AND SHOULD REMAIN
THIS WAY TODAY INTO THIS EVENING PRIOR TO THE LOW EXITING NE OF
THE AREA WATERS. AS A RESULT...THE WATERS WILL OBSERVE A SOLID NE
TO ENE 15 TO 20 KT WIND TODAY...THAT WILL SLOWLY SUBSIDE TO 10-15
KT THIS EVENING AND OVERNIGHT.
SIGNIFICANT SEAS HAVE ALREADY RISEN FROM THE INCREASED NE WINDS
FROM YESTERDAY. WILL BE LOOKING AT A SOLID 3 TO 5 FT INTO EARLY
THIS EVENING...BEFORE DROPPING OFF TO BETWEEN 2 TO 4 FT LATER
TONIGHT. THE EXCEPTION WILL BE THE WATERS BETWEEN LITTLE RIVER
INLET TO MURRELLS INLET WHERE A LIMITED FETCH WILL EXIST FOR
GROWING NE WIND-DRIVEN WAVES. AN UNDERLYING 1 TO 1.5 FOOT ESE
GROUND SWELL AT 10-12 SECOND PERIODS WILL CONTINUE...HOWEVER
THE 4 TO 6 SECOND PERIOD WIND DRIVEN WAVES WILL DOMINATE THE
SIGNIFICANT SEAS SPECTRUM.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...THE NORTHEAST FLOW WILL GIVE WAY TO A
SOUTHEAST FLOW BY MIDDAY SUNDAY AS HIGH PRESSURE GIVES WAY TO
WEAK COASTAL TROUGHING. THE SOUTHEAST FLOW WILL CONTINUE THROUGH
THE END OF THE PERIOD. GUIDANCE IS HINTING AT A FEW HOURS OF NE
WINDS EARLY TUESDAY BUT THIS SHOULD BE FLEETING. SIGNIFICANT SEAS
WILL GENERALLY BE 2-3 FEET.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...RELATIVELY LIGHT WIND FIELDS FOR THE WATERS
WITH WEAK SYNOPTIC FEATURES. OVERALL EXPECT A MOSTLY SOUTHEAST
WIND DIRECTION WITH SPEEDS TEN KNOTS OR LESS. SIGNIFICANT SEAS
WILL BE LIMITED AS WELL WITH 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS RALEIGH NC
907 AM EDT SAT AUG 29 2015
.SYNOPSIS...HIGH PRESSURE CONTINUES TO EXTEND OVER THE AREA FROM THE
NORTH TODAY. AN UPPER LEVEL DISTURBANCE WILL MOVE NORTH ALONG THE
APPALACHIANS ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 905 AM SATURDAY...
WHILE THE LATEST SURFACE ANALYSIS SHOWED HIGH PRESSURE OVER CENTRAL
NORTH CAROLINA...AND SPC MESOANALYSIS DATA SHOWED LOW PRECIPITABLE
WATER VALUES WITH AN 850MB RIDGE IN PLACE AND LIMITED 850MB MOISTURE
ADVECTION...MID- AND HIGH-LEVEL CLOUDS WERE SPREADING OVER CENTRAL
NORTH CAROLINA FROM THE SOUTH. THE LATEST WATER VAPOR IMAGES
INDICATED THE INCREASE OF THE MID-LEVEL MOISTURE WELL...STREAMING
NORTH AHEAD OF AN UPPER LOW OVER THE NORTHERN GULF. THE CANADIAN
CLOUD COVER MODEL...WHICH SEEMED TO HAVE A GOOD HANDLE ON THE CLOUD
COVER...SPREADS HIGH-LEVEL CLOUDS OVER CENTRAL NORTH CAROLINA FROM
THE SOUTHWEST DURING THE DAY...WITH NUMEROUS CLOUDS EXPECTED EVEN
OVER THE NORTHERN COASTAL PLAIN BY 18Z TO 20Z.
EARLY MORNING VISIBLE IMAGES SUGGESTS THE INITIAL SURGE OF HIGH
CLOUDS IS SOMEWHAT THIN...WHICH MAY PROVIDE FOR TIME FOR
TEMPERATURES TO RECOVER. AS SUN BECOMES MORE FILTERED OVER TIME WITH
LIKELY A GREATER DEGREE OF OPAQUE UPPER-LEVEL CLOUDS...THE EFFECT
SHOULD DAMPEN THE TEMPERATURE RISE. STILL...DID NOT LOWER MAXES TOO
MUCH...ONLY ABOUT A DEGREE OR SO...AS THERE MAY BE ENOUGH THIN SPOTS
TO GET WARMING SUFFICIENT FOR ABOUT 10 TO 15 DEGREES OF TEMPERATURE
INCREASE BEYOND THIS WRITING AT AN EARLY SUN TIME. RAP MODEL
SOUNDINGS SHOW MOISTENING ONLY ALOFT...WITH DRY AIR BELOW 500MB AND
A VERY CAPPED AIR MASS.
TONIGHT...MID-HIGH LEVEL CLOUDS WILL THICKEN IN RESPONSE TO THE
APPROACH OF THE NORTHERN GULF S/W THOUGH LIFT TO GENERATE ANY
SHOWERS APPEARS TO BE LACKING. WEAK (EMPHASIS ON WEAK) LOW LEVEL
ISENTROPIC LIFT MAY GENERATE A SHOWER OR SPRINKLES AROUND DAYBREAK
OVER THE FAR SOUTHERN PIEDMONT. THE INCREASING CLOUDINESS AND A
MODIFYING AIR MASS WILL YIELD MIN TEMPS A FEW DEGREES WARMER THAN
LOW TEMPS EXPECTED THIS MORNING. MIN TEMPS MID 60S NORTH TO THE
UPPER 60S SOUTH.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 333 AM SATURDAY...
HAVE TRENDED FORECAST THIS PERIOD A LITTLE WETTER...ESPECIALLY
SUNDAY NIGHT ACROSS THE PIEDMONT AND SANDHILLS.
ATMOSPHERE WILL CONTINUE TO MOISTEN AS NORTHERN GULF SYSTEM LIFTS
NEWD ACROSS GA AND INTO THE SOUTHERN APPALACHIANS LATE IN THE DAY.
THE APPROACH OF THIS SYSTEM WILL INDUCE A LOW LEVEL SELY
FLOW...RESULTING IN AN UPSLOPE COMPONENT TO THE LOW LEVEL FLOW OVER
THE SOUTHERN-WESTERN PIEDMONT. THE GFS SOLUTION IS A BIT MORE
AGGRESSIVE WITH THIS SCENARIO COMPARED TO THE NAM WHILE THE 00Z
ECMWF FAVORS THE GFS SOLUTION. INCREASING UPPER DIVERGENCE BY SUNDAY
AFTERNOON IN CONJUNCTION WITH A SLIGHTLY UNSTABLE AND INCREASINGLY
MOIST AIR MASS SHOULD SUPPORT THE DEVELOPMENT OF A FEW SHOWERS AND
AN ISOLATED STORM...MAINLY ACROSS PORTIONS OF THE SOUTHERN PIEDMONT
AND THE SANDHILLS. MAY SEE ADDITIONAL COVERAGE OVER THE
SANDHILLS/SOUTHERN COASTAL PLAIN DUE TO THE INLAND MOVING SEABREEZE.
THUS...WILL INCREASE POPS BIT FROM THE PREVIOUS FORECAST...UP TO 40
PERCENT OVER THE SOUTH AND WEST SECTIONS BY LATE IN THE DAY/SUNDAY
EVENING.
DUE TO EXPECTED EXTENSIVE CLOUDINESS...HAVE ADJUSTED MAX TEMPS DOWN
A BIT OVER THE WEST AND SW...WITH LITTLE CHANGE ELSEWHERE. IF CLOUDS
ARE LOWER/THICKER THAN EXPECTED OR SHOWER COVERAGE MORE EXTENSIVE BY
AFTERNOON...MAX TEMPS MAY END UP BEING 3-4 DEGREES COOLER THAN
FORECAST EVERYWHERE.
SUNDAY NIGHT...S/W LIFTS NEWD IMMEDIATELY WEST OF OUR REGION LATE IN
THE NIGHT...MAXIMIZING UPPER DIVERGENCE. IN THE 850-700MB LAYER WEAK
SPEED CONVERGENCE IN THE MOIST LAYER. THUS...SHOULD SEE A THREAT FOR
A FEW SHOWERS THROUGHOUT THE NIGHT...MAINLY ACROSS THE PIEDMONT. MIN
TEMPS MAINLY IN THE UPPER 60S TO NEAR 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 355 AM SATURDAY...
THE MODELS ARE IN BETTER AGREEMENT TODAY REGARDING THE
EJECTION/PROGRESSION OF A SHORTWAVE TROUGH --INITIALLY A CLOSED LOW
OVER THE CENTRAL GULF COAST THIS MORNING-- FROM THE CENTRAL
APPALACHIANS TO THE MIDDLE ATLANTIC COAST ON MON. MEANWHILE...AN
UPSTREAM KICKER SHORTWAVE TROUGH WILL AMPLIFY INTO THE SOUTHERN
PLAINS TO LOWER AND MID MS VALLEY AND RE-CARVE THE TROUGH
WESTWARD...AND CONSEQUENTLY ALLOW THE SUB-TROPICAL RIDGE TO BULGE
WESTWARD INTO THE SOUTHEAST US. A STRONGLY POSITIVELY-TILTED SHEAR
AXIS WILL SEPARATE THE SOUTHEASTERN RIDGE AND ANOTHER FORECAST TO
BUILD ACROSS THE OH VALLEY AND GREAT LAKES...AND THIS FEATURE WILL
INITIALLY DRAW TROPICAL MOISTURE ASSOCIATED WITH (AND IN ADVANCE OF)
ERIKA...NORTHWARD THROUGH THE CAROLINAS EARLY NEXT WEEK.
THEREAFTER...MOISTURE FROM (AND THE OVERALL INFLUENCE OF)
ERIKA...WILL BE DEPENDENT ON HOW ERIKA EVOLVES DURING THE NEXT
SEVERAL DAYS...WHICH IS A RELATIVELY LOW CONFIDENCE FORECAST.
THE ENVELOPE OF GUIDANCE SOLUTIONS HAS CONTINUED A WESTWARD TREND
WITH THE TRACK OF WHAT BECOMES OF ERIKA...WITH THE PREFERRED NHC
TRACK NOW THROUGH THE EASTERN GULF OF MEXICO/ALONG THE WEST COAST OF
FL EARLY NEXT WEEK...TO A POSITION NEAR THE FL PANHANDLE OR SOUTHERN
GA BY WED. CONSIDERABLE FORECAST UNCERTAINTY REMAINS WITH ERIKA...
HOWEVER...SINCE THE CIRCULATION MAY DISSIPATE ALTOGETHER DUE TO THE
INTERACTION WITH BOTH LAND AND A HOSTILE WIND SHEAR ENVIRONMENT
DURING THE NEXT 24-36 HOURS. OR IF IT SURVIVES... REGENERATION/
STRENGTHENING WILL BE POSSIBLE OVER THE WARM WATERS AND IN A
WEAKENING WIND SHEAR ENVIRONMENT OVER THE FL STRAITS AND EASTERN GOM.
REGARDLESS...IT STILL APPEARS THAT THE LOW LEVEL VORTICITY
CENTER...IN WHATEVER STATE IT MAY BE BY THE MIDDLE OF NEXT
WEEK...WILL LIKELY BE SUPPRESSED MOSTLY SOUTH AND/OR WEST OF CENTRAL
NC BY THE MERGING OF THE AFOREMENTIONED RIDGES ALOFT FROM THE GREAT
LAKES TO THE SE COAST. AS SUCH...OUR SENSIBLE WEATHER WILL LIKELY
INSTEAD BE INFLUENCED INDIRECTLY BY ASSOCIATED MOISTURE STREAMING
NNE ALONG THE AFOREMENTIONED SHEAR AXIS...WHICH WOULD RESULT IN BOTH
VARIABLY CLOUDY CONDITIONS AND SUPPORT FOR SLIGHTLY ABOVE CLIMO
PRECIPITATION CHANCES - HIGHEST SOUTH IN CLOSEST PROXIMITY TO THE
REMNANTS OF ERIKA. TEMPERATURES SHOULD BE CLOSE TO CLIMO - PERHAPS A
LITTLE BELOW /ABOVE FOR HIGHS/LOWS DEPENDING ON TIMING AND EXTENT OF
MOISTURE/CLOUD COVER.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 AM SATURDAY...
THERE IS A HIGH PROBABILITY OF VFR CONDITIONS PERSISTING ACROSS
CENTRAL NC THROUGH EARLY SUNDAY. HIGH PRESSURE CENTERED OVER THE
NORTHERN MID ATLANTIC WILL EXTEND SOUTH INTO CENTRAL NC...CAUSING
THE VFR CONDITIONS. A DECK OF HIGH CLOUDS WILL PREVAIL LATER TODAY
AND TONIGHT WITH BASES ABOVE 10K FEET. SFC WINDS WILL BE GENERALLY
LIGHT AND VARIABLE THOUGH KFAY AND KRWI SHOULD SEE A PREDOMINATE
EAST-NE SFC WIND LATER THIS MORNING THROUGH EARLY AFTERNOON...
BETWEEN 7-10KTS.
WHILE VFR CONDITIONS WILL LIKELY CONTINUE INTO EARLY NEXT
WEEK...THERE WILL BE A THREAT FOR SCATTERED CONVECTION SUNDAY
THROUGH MONDAY AS AN UPPER DISTURBANCE LIFTS NWD ACROSS THE
CAROLINAS FROM THE DEEP SOUTH. MVFR CEILINGS/VISIBILITY COULD OCCUR
IN VICINITY OF THE CONVECTION.
THE AIR MASS WILL BECOME INCREASINGLY MOIST AND UNSTABLE TUESDAY AND
WEDNESDAY...SUGGESTING A BETTER CHANCE FOR PERIODS OF MVFR/IFR
CEILINGS DUE TO STRATUS IN THE OVERNIGHT-EARLY MORNING HOURS...AND
SCATTERED CONVECTION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF/WSS
NEAR TERM...DJF/WSS
SHORT TERM...WSS
LONG TERM...26
AVIATION...WSS
AREA FORECAST DISCUSSION...UPDATED
NWS PENDLETON OR
506 AM PDT SAT AUG 29 2015
UPDATED AVIATION DISCUSSION
.SHORT TERM...TODAY THROUGH MONDAY...POTENT UPPER LEVEL TROUGH OFF
THE OREGON COAST WILL LIFT NEWD INTO NW WASHINGTON AND DEAMPLIFY AS
IT MOVES INTO BRITISH COLUMBIA TODAY AND TONIGHT. THE MAIN IMPACT
FROM THIS SYSTEM WILL BE SOME RAIN ALONG THE CASCADES AND GUSTY SW
WINDS FROM MID MORNING UNTIL LATE THIS AFTERNOON. WIND ADVISORIES
ARE IN EFFECT FOR MUCH OF THE LOWER ELEVATIONS. WITH LITTLE RAIN
EXPECTED EAST OF THE CASCADES EXPECT SOME BLOWING DUST AS WELL.
BLOWING DUST ADVISORIES ARE IN EFFECT FOR THE BLUE MOUNTAIN
FOOTHILLS...YAKIMA VALLEY AND COLUMBIA BASIN. LOOKING AT THE PAST
FEW RUNS OF THE HRRR IT APPEARS THAT THE STRONGEST WIND TODAY WILL
BE OVER THE YAKIMA VALLEY AND SIMCOE HIGHLANDS WITH GUST POTENTIAL
REACHING 50 TO 55 MPH LATE THIS MORNING INTO EARLY THIS AFTERNOON.
THIS MAKES SENSE BECAUSE THIS AREA IS CLOSER TO THE TRACK OF THE
UPPER TROUGH. WINDS WILL DECREASE QUICKLY BY EARLY EVENING. AS A
SECOND UPPER TROUGH APPROACHES LATER TONIGHT RAIN IS EXPECTED TO
SPREAD EAST OF THE CASCADES. THIS RAIN WILL MOVE ACROSS THE ENTIRE
FORECAST AREA ON SUNDAY. BUMPED UP POPS QUITE A BIT FOR SUNDAY TO
REFLECT THE MODELS WETTER TRENDING...AND POPS MAY NEED TO BE RAISED
FURTHER. THERE IS A CHANCE FOR QUARTER INCH AMOUNTS WITH THIS SYSTEM
OVER A WIDE AREA WHICH WOULD REALLY HELP WITH THE ONGOING FIRES. BY
MONDAY THE TROUGH WILL HAVE MOVED EAST OF THE REGION WITH GENERALLY
DRY CONDITIONS AND COOL TEMPERATURES. 78
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY..THE AREA WILL BE UNDER
THE INFLUENCE OF AN UPPER LEVEL TROUGH THROUGH THE LONG TERM PERIOD
AND UNSETTLED WEATHER IS EXPECTED. ON MONDAY NIGHT THE TROUGH WILL
BE BROAD AND SHALLOW WITH A WESTERLY FLOW OVER THE AREA. AN UPPER
LOW WILL BE OFF THE NORTHERN BRITISH COLUMBIA COAST AND WILL SINK
SOUTH, ENDING UP NEAR NORTHERN VANCOUVER ISLAND BY TUESDAY
AFTERNOON. RAIN SHOWERS WILL STRUGGLE TO GET VERY FAR PAST THE
CASCADE CREST THOUGH BY TUESDAY AFTERNOON, THERE SHOULD BE A FEW
LIGHT SHOWERS AS FAR EAST AS YAKIMA AND ELLENSBURG. THE REST OF THE
AREA WILL REMAIN DRY. WINDS WILL BECOME BREEZY TUESDAY AFTERNOON.
THE UPPER LOW WILL DEEPEN THE TROUGH AND TURN THE FLOW OVER OUR AREA
MORE SOUTHWESTERLY. A FRONT WILL MOVE THROUGH THE AREA TUESDAY NIGHT
AND WEDNESDAY BRINGING A CHANCE OF LIGHT RAIN TO THE ENTIRE AREA.
ANOTHER IMPULSE WILL MOVE THROUGH THE TROUGH ON THURSDAY AND BRING A
CHANCE OF RAIN AND A SLIGHT CHANCE OF THUNDERSTORMS TO THE MOUNTAINS
WITH A SLIGHT CHANCE OF RAIN IN CENTRAL OREGON AND THE BLUE MOUNTAIN
FOOTHILLS. THE GFS SHOWS THE IMPULSE CARVING THE TROUGH FURTHER
SOUTH ON FRIDAY WITH A SLIGHT CHANCE OF THUNDERSTORMS IN THE EASTERN
MOUNTAINS. THE ECMWF IS LESS VIGOROUS WITH THIS IMPULSE AND DOES NOT
SHOW ANY PRECIPITATION BUT DOES DEEPEN THE TROUGH SOMEWHAT. HAVE
LEANED TOWARDS THE GFS AND PUT A SLIGHT CHANCE OF THUNDERSTORMS IN
THE EASTERN MOUNTAINS. ON SATURDAY, BOTH MODELS SHOW THE TROUGH
STARTING TO MOVE EASTWARD WITH A SLIGHT CHANCE OF THUNDERSTORMS
MAINLY IN WALLOWA COUNTY AND THE HIGHER TERRAIN IN THE REST OF THE
EASTERN MOUNTAINS. TUESDAY WILL SEE TEMPERATURES IN THE 70S AND
LOWER 80S. WEDNESDAY AND THURSDAY WILL BE COOLER WITH HIGHS IN THE
MID 60S TO MID 70S. FRIDAY AND SATURDAY WILL SEE TEMPERATURES BACK
IN THE MID 70S TO LOWER 80S WITH MID 60S TO MID 70S IN THE
MOUNTAINS. PERRY
&&
.AVIATION...12Z TAFS...VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24
HOURS HOWEVER A FRONTAL PASSAGE EARLY TO MIDDAY SATURDAY WILL CAUSE
MVFR AND PERHAPS IFR VISIBILITIES DUE TO BLOWING DUST AT KPSC, KALW,
KPDT AND KYKM. WINDS WILL INCREASE RAPIDLY IN THE NEXT FEW HOURS AND
WEST TO SOUTHWEST WINDS OF 20 TO 30 KTS WITH GUSTS TO 40 KTS ARE
EXPECTED FROM 17Z TO 01Z BEFORE WINDING DOWN TO BELOW 15 KTS BY 04Z.
KDLS IS EXPECTED TO HAVE WINDS OF 10 TO 20 KTS WITH GUSTS TO 30 KTS
DUE TO THE EAST/WEST ORIENTATION OF THE COLUMBIA GORGE BEING
SOMEWHAT SHELTERED FROM THE SOUTHWEST WINDS. CEILINGS WILL BE
GENERALLY SCATTERED TO BROKEN ABOVE 5000 FEET AGL. RAIN SHOWERS WILL
BE CONFINED TODAY TO IN AND NEAR THE CASCADES WITH KDLS HAVING -SHRA
THROUGH 20Z AND KRDM AND KBDN HAVING VCSH THROUGH 19Z. ANOTHER
DISTURBANCE WILL BRING -SHRA TO KDLS AND KYKM AFTER 08Z. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 81 54 72 50 / 10 10 50 10
ALW 83 61 73 54 / 10 10 60 10
PSC 83 58 76 56 / 10 10 60 10
YKM 74 53 70 48 / 20 50 40 10
HRI 85 57 74 53 / 10 10 50 10
ELN 74 53 72 50 / 30 50 50 10
RDM 77 48 67 39 / 20 10 50 10
LGD 83 47 69 46 / 20 10 50 10
GCD 82 46 71 36 / 10 10 40 10
DLS 80 61 75 56 / 30 70 70 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 6 PM PDT THIS
EVENING FOR ORZ510-511.
RED FLAG WARNING FROM 7 AM THIS MORNING TO 7 PM PDT THIS EVENING
FOR ORZ640>645.
BLOWING DUST ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS
EVENING FOR ORZ044-507-508.
WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS EVENING
FOR ORZ044-507-508.
WA...RED FLAG WARNING FROM 7 AM THIS MORNING TO 7 PM PDT THIS EVENING
FOR WAZ641-643-645-675.
BLOWING DUST ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS
EVENING FOR WAZ027>029.
WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM PDT THIS EVENING
FOR WAZ027>029-521.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
78/83/83
AREA FORECAST DISCUSSION
NWS PORTLAND OR
308 AM PDT SAT AUG 29 2015
.SYNOPSIS...AN USUALLY EARLY AND STRONG LOW PRESSURE WILL PRODUCE
WIDESPREAD RAIN AND STRONG WINDS ACROSS NORTHWEST OREGON AND
SOUTHWEST WASHINGTON SATURDAY MORNING. A FEW THUNDERSTORMS EMBEDDED
IN THE RAIN MAY ENHANCE THE WIND THREAT SATURDAY MORNING. A SECOND
FRONT PUSHING INTO THE REGION FROM THE NORTHWEST SATURDAY NIGHT WILL
PRODUCE ANOTHER ROUND OF RAIN. ADDITIONAL SHOWERS WILL FOLLOW ON
SUNDAY. EXPECT COOL WEATHER AND ADDITIONAL ROUNDS OF SHOWERS FOR MUCH
OF THE UPCOMING WORK WEEK.
&&
.SHORT TERM...A FEW PREFRONTAL SHOWERS REMAIN OVER THE NORTH VALLEY
THIS MORNING WITH THE FRONTAL RAIN BAND MOVING ONSHORE. RADAR ALREADY
SHOWING SOME HIGHER REFLECTIVITY ACTIVITY OVER THE COAST RANGE AND
EVEN A FEW LIGHTNING STRIKES. ALTHOUGH THE RAINBAND IS NARROW...ITS
CURRENTLY MOVING MUCH MORE NORTH THAN EAST SO IT WILL BE SLOW TO
WORK ITS WAY INLAND AND MAY DROP 0.10 TO 0.20 INCHES OF RAIN PER
HOUR WITH MORE IN EMBEDDED STRONGER SHOWERS OR THUNDERSTORMS. THERE
DOES NOT APPEAR TO BE ANY RAIN IMMEDIATELY FOLLOWING THIS FRONTAL
BAND...SO THERE WILL BE A DEFINITE BREAK IN RAIN FROM THE TIME THE
BAND MOVES THROUGH TO WHEN ANY SHOWERS BEGIN TO POP UP THIS
AFTERNOON WITH DAYTIME HEATING. HAVE DRIED THE FORECAST OUT QUITE A
BIT 18Z TODAY TO 00Z SUNDAY BUT THE RAIN MAY HAVE MOVED THROUGH
EARLIER THAN EVEN THAT.
THE PARENT LOW CONTINUES TO STRENGTHEN AND IS CURRENTLY CENTERED
ABOUT 200 MILES WEST OF NORTH BEND ACCORDING TO LATEST IR SATELLITE
IMAGERY. BASED ON COMPARISON OF BUOY OBS AND 06Z NAM AND GFS
FORECASTS...LOOKS LIKE THE LOW IS AROUND 989 MB RIGHT NOW...OR
SLIGHTLY STRONGER THAN THE NAM AND GFS HAVE. THE 08Z HRRR SHOWS A
STRONGER LOW CURRENTLY AND FORECASTS THE PRESSURE DROPPING TO 985 MB
AT ITS CLOSEST APPROACH TO THE OREGON COAST...ABOUT 100 MILES
OFFSHORE. THIS WOULD BE 4 MB STRONGER THAN THE NAM AND GFS CURRENTLY
SHOW BUT WITH A SIMILAR TRACK AND SEEMS FAIRLY REALISTIC. HRRR ALSO
SHOWS RATHER IMPRESSIVE PRESSURE RISES BEHIND THE LOW LATE THIS
MORNING WITH 6+ MB IN 3 HOURS OVER THE EXTREME NW OREGON AND SW
WASHINGTON AREAS...MOSTLY CENTERED AROUND CLATSOP AND PACIFIC
COUNTIES. ALSO SEEING HIGH PRESSURE RISES JUST OFFSHORE THROUGH THE
CENTRAL OREGON COAST WHICH SHOULD TRANSLATE TO HIGH
WINDS...ESPECIALLY FOR THE BEACHES AND HEADLANDS. WILL KEEP HIGH WIND
WARNINGS IN PLACE AS IS. PRESSURE RISES AND PRESSURE GRADIENT THROUGH
THE VALLEY ARE LESS IMPRESSIVE WITH THE NORTH-SOUTH GRADIENT PEAKING
ONLY AT ABOUT 4 TO 5 MB BUT CONDITIONS WILL BE NOTICEABLY WINDY
NONETHELESS. 850 MB WINDS IN THE VALLEY ARE FORECAST TO BE 40 TO 50
KT WHEN THIS MORNING`S RAIN COMES THROUGH...SO ANY CONVECTION COULD
MIX DOWN SOME GOOD GUSTS. WILL LEAVE WIND ADVISORY AS IS SINCE THIS
IS AN ANOMALOUSLY STRONG WIND EVENT FOR LATE AUGUST...EVEN THOUGH
TECHNICAL CRITERIA MAY NOT BE MET.
MODELS HAVE TRENDED WETTER WITH A SECOND FRONT DROPPING SOUTHEASTWARD
OUT OF THE GULF OF ALASKA THAT WILL PUSH A HEALTHY DOSE OF RAIN
ACROSS THE AREA SATURDAY NIGHT. DECENT ONSHORE FLOW AND INSTABILITY
SHOULD LEAD TO MORE SHOWERS AND POSSIBLY A WET THUNDERSTORM OR TWO
SUNDAY.
BELOW AVERAGE TEMPERATURES AND ADDITIONAL ROUNDS OF WET WEATHER
APPEAR LIKELY NEXT WEEK. BOWEN
.LONG TERM (PREVIOUS DISCUSSION)...MONDAY NIGHT THROUGH FRIDAY. THE
FALL-LIKE WEATHER PATTERN WILL CONTINUE NEXT WEEK WITH PRIMARILY
COOLER THAN NORMAL TEMPERATURES...CLOUDY CONDITIONS...AND CHANCES FOR
ADDITIONAL RAIN. A TROUGH WILL REMAIN NEAR THE PACIFIC NORTHWEST
COAST THROUGH MOST OF THE PERIOD WITH SOME RAIN AT TIMES...ESPECIALLY
DURING THE EARLY AND MIDDLE PARTS OF NEXT WEEK. LITTLE CHANGE MADE TO
THE CURRENT FORECAST. TOLLESON
&&
.AVIATION...MOIST SW FLOW ALOFT OVER REGION...WITH RAIN INCREASING
THIS AM. WILL SEE FRONT PUSH N ACROSS THE REGION LATER THIS AM...
WITH INCREASING S WINDS. STRONGEST WINDS WILL BE ON COAST AND
OVER COAST RANGE...WITH S WIND GUSTS OF 40 TO 55 KT FOR THOSE
AREAS AND LESSER WINDS FURTHER INLAND. AT 2 AM...GENERALLY VFR
CONDITIONS. BUT WILL SEE INCREASING MVFR ALONG THE COAST BY 12Z.
RAIN WILL END BY 18Z FOR MOST AREAS...WITH CIGS BREAKING UP A BIT
AS MORE UNSTABLE AIR MASS WITH SHOWERS MOVES INTO REGION FOR THE
AFTERNOON. WOULD NOT BE SURPRISED TO SEE TRANSITION BACK TO VFR AT
TIMES AFTER 20Z. CIGS WILL LOWER BACK TO MVFR TONIGHT AS ANOTHER
FRONT AND MORE RAIN PUSHES INTO THE REGION.
KPDX AND APPROACHES...VFR...WITH RAIN UNTIL 18Z...THEN LIKELY TO
SEE A MIXTURE OF VFR WITH OCCASIONAL MVFR AS MORE SHOWERY PATTERN
PUSHES INTO REGION. WILL HAVE S WINDS GUSTING 25 TO 35 KT BETWEEN
17Z AND 23Z. WINDS EASE AFTER 00Z...BUT WILL HAVE INCREASING MVFR
AS RAIN INCREASES LATER SAT NIGHT. ROCKEY.
&&
.MARINE...MODELS CONTINUE TO BE WELL INITIALIZED WITH THE STRONG
LOW PRES NOW SITTING ABOUT 250 MILES SOUTHWEST OF NEWPORT THIS AM.
THIS LOW WILL LIFT NE ACROSS THE OREGON COASTAL WATERS AND INTO
NW WASHINGTON TODAY. BUT APPEARS THE ACTUAL LOW IS STRONGER THAN
THE MODELS INDICATE. THE LOW WILL GRADUALLY WEAKEN TODAY AS IT
MOVES NE...STRONGEST WINDS LOOK TO REMAIN S OF THE COLUMBIA RIVER.
SO...HAVE ISSUED STORM WARNING FOR COASTAL WATERS S OF THE
COLUMBIA RIVER WHERE THERE IS MODERATE TO HIGH POTENTIAL FOR 50 KT
GUSTS. REST OF THE REGION WILL REMAIN UNDER A GALE WARNING.
SEAS WILL BE BUILDING AS WINDS INCREASE. STILL LOOKS GOOD FOR SEAS
TO BE RUNNING AT 13 TO 17 FT BY MID TO LATE THIS AM. SEAS HOLD IN
THAT RANGE THROUGH THE DAY...BUT DROP BACK THIS EVENING.
WINDS WILL EASE LATER THIS AFTERNOON...LIKELY BELOW 25 KT BY 8 PM.
SEAS WILL ALSO SUBSIDE AS WINDS EASE...PROBABLY AROUND 8 TO 10 FT
LATER TONIGHT INTO SUNDAY.
UNSETTLED WEATHER CONTINUES INTO NEXT WEEK WITH SEAS STAYING 6 TO
9 FT THROUGH AT LEAST MIDWEEK. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FROM 8 AM THIS MORNING TO 3 PM PDT THIS AFTERNOON
FOR GREATER PORTLAND METRO AREA-LOWER COLUMBIA.
HIGH WIND WARNING UNTIL 1 PM PDT THIS AFTERNOON FOR CENTRAL
OREGON COAST.
WIND ADVISORY UNTIL NOON PDT TODAY FOR CENTRAL WILLAMETTE
VALLEY-SOUTH WILLAMETTE VALLEY.
HIGH WIND WARNING FROM 6 AM THIS MORNING TO 2 PM PDT THIS
AFTERNOON FOR COAST RANGE OF NORTHWEST OREGON-NORTH OREGON
COAST.
HIGH WIND WARNING FROM 5 AM EARLY THIS MORNING TO NOON PDT TODAY
FOR CENTRAL COAST RANGE OF WESTERN OREGON.
WA...WIND ADVISORY FROM 8 AM THIS MORNING TO 3 PM PDT THIS AFTERNOON
FOR GREATER VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ COUNTY.
HIGH WIND WARNING FROM 8 AM THIS MORNING TO 3 PM PDT THIS
AFTERNOON FOR WILLAPA HILLS.
HIGH WIND WARNING FROM 8 AM THIS MORNING TO 2 PM PDT THIS
AFTERNOON FOR SOUTH WASHINGTON COAST.
PZ...STORM WARNING FROM 6 AM TO NOON TODAY ON ALL COASTAL WATERS
SOUTH OF THE COLUMBIA RIVER.
GALE WARNING UNTIL 8 PM TODAY ON ALL COASTAL WATERS THROUGH
8 PM TODAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR CONDITIONS
TODAY AND THIS EVENING.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
616 AM CDT SAT AUG 29 2015
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT SAT AUG 29 2015/
UPDATE...
UPDATED TO INCREASE THE POPS FOR TODAY TO 40 PERCENT ACROSS
PORTIONS OF NORTHEAST AR THAT INCLUDES RANDOLPH...LAWRENCE AND
EXTREME WESTERN PORTIONS OF CLAY COUNTY. THE HRRR MODEL INDICATES
SHOWERS SPREADING INTO THIS AREA THIS MORNING. RADARS ALREADY
INDICATE SHOWERS JUST TO THE NORTHWEST GRADUALLY SLIPPING TO THE
SOUTHEAST.
JCL
DISCUSSION... /ISSUED 348 AM CDT SAT AUG 29 2015/
EARLY THIS MORNING...TEMPERATURES WERE A LITTLE WARMER THAN IN
RECENT DAYS RANGING FROM THE MIDDLE 60S TO LOWER 70S. MIDDLE AND
HIGH LEVEL CLOUDS STRETCHED FROM NORTHWEST TN AND THE MO BOOTHEEL
INTO NORTHEAST AR.
THE MIDSOUTH WILL BE AFFECTED BY TWO SYSTEMS THE NEXT COUPLE OF
DAYS...ONE AN UPPER LEVEL TROUGH APPROACHING FROM THE NORTHWEST
AND ANOTHER AN UPPER LEVEL LOW ALONG THE NORTHERN GULF COAST THAT
WILL LIFT NORTHEASTWARD. BOTH OF THESE FEATURES ARE FAIRLY WEAK.
THE LATEST GUIDANCE INDICATES HIGHER POPS ESPECIALLY FOR TONIGHT
AND SUNDAY THAN THE EARLIER GUIDANCE...DID RAISE THE POPS SOME BUT
CONFIDENCE IS NOT HIGH ENOUGH TO GO GREATER THAN 30 PERCENT POPS
ATTM. LATER FORECASTS MAY NEED TO RAISE THE POPS IN SOME LOCATIONS
DURING THIS TIMEFRAME.
FOR TODAY...AN UPPER LEVEL TROUGH FROM THE GREAT LAKES TO THE
CENTRAL PLAINS WILL MOVE SOUTHEASTWARD APPROACHING NORTHEAST AR.
INDICATED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR A SMALL
PORTION OF NORTHEAST AR TODAY. MEANWHILE...AN UPPER LEVEL LOW
WILL BE LOCATED ALONG THE MS AND AL COAST. THIS LOW WILL HELP TO
PUSH MORE MOIST AND UNSTABLE AIR INTO THE MIDSOUTH FROM THE EAST.
CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
FOR NORTHEAST MS AND THE TN RIVER VALLEY OF WEST TN. CLOUDS WILL
BE ON THE INCREASE ACROSS THE MIDSOUTH IN ASSOCIATION WITH BOTH OF
THESE SYSTEMS. TEMPERATURES WILL BE SEASONABLY WARM.
FOR TONIGHT...THE UPPER LEVEL TROUGH WILL PUSH INTO THE MIDSOUTH
FROM THE NORTHWEST WITH THE UPPER LOW ALONG THE CENTRAL GULF COAST
MOVING NORTHEASTWARD INTO CENTRAL AL. INDICATED A CHANCE OF
SHOWERS AND THUNDERSTORMS FOR MOST OF THE REGION.
ON SUNDAY...THE UPPER LEVEL LOW OVER CENTRAL AL WILL CONTINUE TO
PUSH NORTHEASTWARD WITH A WEAK BROAD UPPER LEVEL TROUGH OVER THE
MIDSOUTH. CONTINUED TO MENTION A CHANCE OF SHOWERS AND
THUNDERSTORMS. CLOUDS ARE EXPECTED TO DECREASE FROM THE SOUTHWEST.
MONDAY...AN UPPER LEVEL TROUGH WILL BE WEST OF THE MIDSOUTH WHILE
UPPER LEVEL RIDGING WILL BE TO THE EAST WITH WEAK SOUTHERLY FLOW
SURFACE AND ALOFT ACROSS THE REGION. THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY FOR A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS.
IT WILL FEEL LIKE SUMMER WITH PLENTY OF SUNSHINE BOOSTING
TEMPERATURES TO NEAR NORMAL READINGS.
TUESDAY...THE UPPER LEVEL RIDGE IS FORECAST TO BUILD ACROSS THE
MIDSOUTH FROM THE EAST SUPPRESSING MOST CONVECTION. KEPT POPS
BELOW MENTIONABLE LEVELS.
TOWARD THE MIDDLE AND END OF NEXT WEEK...INCREASING MOISTURE IS
FORECAST TO SPREAD INTO THE REGION FROM THE SOUTHEAST AS UPPER
LEVEL RIDGING WEAKENS. THIS WILL RESULT IN A RETURN OF A SMALL
CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. TEMPERATURES WILL
REMAIN SEASONABLY WARM TO HOT WITH NO COLD FRONTAL PASSAGES
EXPECTED.
JCL
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH LIGHT SSE
WINDS.
TVT
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TUCSON AZ
150 PM MST SAT AUG 29 2015
.SYNOPSIS...A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE WEEKEND
INTO EARLY NEXT WEEK. GRADUALLY DRIER CONDITIONS WILL THEN LIMIT
THUNDERSTORMS TO EAST OF TUCSON THE SECOND HALF OF NEXT WEEK. HOTTER
THAN AVERAGE TEMPERATURES FOR THE NEXT FEW DAYS FOLLOWED BY
TEMPERATURES FALLING TO NEAR AVERAGE AROUND THE MIDDLE OF THE
UPCOMING WEEK.
&&
.DISCUSSION...SATELLITE AND RADAR IMAGERY WERE SHOWING SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS SOUTHEAST ARIZONA EARLY
THIS AFTERNOON. MOST OF THE ACTIVITY HAS BEEN IN THE MOUNTAINS BUT A
FEW HAVE MANAGED TO DEVELOP OVER THE WESTERN DESERTS OF PIMA COUNTY
AROUND THE TOWNS OF WHY AND AJO. THE WINDS ALOFT REMAINED RATHER
LIGHT SO THE STORMS HAVE BEEN VERY PULSE LIKE IN NATURE WITH LITTLE
MOVEMENT SO FAR. LATEST HRRR CONTINUED TO SHOW SMALL SHOWERS AND
THUNDERSTORMS DOTTED ACROSS MUCH OF SOUTHEAST ARIZONA THROUGH LATE
THIS EVENING. MUCH MORE THAN SUGGESTED BY THE MORNING UPPER-AIR
SOUNDING AT KTWC. AT ANY RATE...LOOKING AT MORE THUNDERSTORM
ACTIVITY COMPARED TO YESTERDAY ALREADY. MODELS SUGGEST ANOTHER
RATHER ACTIVE DAY FOR SUNDAY AS WELL...WITH A LITTLE MORE ORGANIZED
THUNDERSTORMS RATHER THAN PULSE IN NATURE. THEREAFTER...
THUNDERSTORMS WILL DIMINISH IN COVERAGE EACH DAY AS A DRIER
SOUTHWESTERLY FLOW EVOLVES IN RESPONSE TO A LOW PRESSURE SYSTEM
PASSES THROUGH THE NORTHERN TIER STATES. HIGH TEMPERATURES WILL
REMAIN SEVERAL DEGREES ABOVE NORMAL...THEN LOWER TO NEAR SEASONAL
READINGS AROUND WEDNESDAY.
&&
.AVIATION...VALID THRU 31/00Z.
SCT TO LOCALLY BKN CLOUDS AT 8-12 KFT AGL. ISOLD SHRA/TSRA
INCREASING IN COVERAGE THIS AFTERNOON WITH KDUG AND KOLS TERMINALS
LIKELY AFFECTED DIRECTLY. FOR THE KTUS TERMINAL TSRA WILL DEVELOP
OVER THE HIGH TERRAIN AROUND THE AREA WITH A SMALL CHANCE OF ONE
AFFECTING THE TERMINAL 29/22Z THRU 30/02Z. BRIEF MVFR CONDITIONS
AND GUSTY WINDS OF 30 TO 40 KTS WILL BE POSSIBLE IN AND AROUND
STRONGER STORMS. AFTER 30/05Z SKIES CLEARING WITH A REPEAT ON
SUNDAY WITH RESPECT TO CLOUD AND SHRA/TSRA REDEVELOPMENT. OUTSIDE
OF THUNDERSTORM INFLUENCE SURFACE WINDS WILL GENERALLY BE UNDER 10
KTS. AFTER AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
INTO THE EARLY EVENING BEFORE DYING OFF LATE EVENING HOURS. PRIME
CONCERN IS STRONG WINDS AND HEAVY RAIN DUE TO SLOW MOTIONS. THIS
BASIC IDEA WILL CONTINUE INTO EARLY NEXT WEEK...WITH DAILY AFTERNOON
AND EVENING STORMS EXPECTED. STARTING MONDAY STORMS WILL TEND TO BE
MORE FOCUSED OVER EASTERN ZONES...WITH SIGNIFICANTLY DIMINISHED
THUNDERSTORM ACTIVITY FROM WEDNESDAY ON. THUNDERSTORMS ARE EXPECTED
TO BE WET AND AS IS TYPICAL MAY PRODUCE STRONG...GUSTY AND ERRATIC
WINDS WITH THE STRONGER THUNDERSTORMS.
THROUGH SUNDAY GENERALLY LIGHT TERRAIN DRIVEN WINDS ARE EXPECTED.
FROM MONDAY ONWARD A WEST TO SOUTHWEST FLOW WILL GRADUALLY DEVELOP
ACROSS ARIZONA. THE STRONGEST WINDS WILL BE ACROSS ZONE
150...PEAKING IN THE 15-20 MPH RANGE. THIS FLOW WILL ALSO STEADILY
PUSH THE MOISTURE OUT OF THE REGION FOR DECREASING CHANCES OF
THUNDERSTORMS WEDNESDAY THROUGH FRIDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
908 AM MST SAT AUG 29 2015
.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT WILL KEEP HIGH TEMPERATURES WELL ABOVE
SEASONAL NORMALS TODAY WITH HOTTER LOWER DESERTS REACHING OR
EXCEEDING 110. THERE WILL BE SUFFICIENT MOISTURE EAST OF THE LOWER
COLORADO RIVER TO SUPPORT ISOLATED TO SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THROUGH SUNDAY. STARTING MONDAY DRIER WESTERLY
FLOW ALOFT WILL PUSH THE MOISTURE OFF TO THE EAST LIMITING STORM
CHANCES PRIMARILY TO HIGHER TERRAIN AREAS TO THE EAST OF PHOENIX.
THERE WILL BE A GRADUAL COOLING TREND STARTING SUNDAY WITH CENTRAL
DESERTS HIGH TEMPERATURES DROPPING TO AROUND SEASONAL NORMALS BY THE
MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...
CLEAR TO MOSTLY CLEAR MORNING SKIES PERSIST ACROSS THE FORECAST
AREA...AND ACROSS NEARLY THE WHOLE STATE FOR THAT MATTER...WITH ONLY
SOME FEW TO SCT MID LEVEL CLOUDS ACROSS THE FAR SE CORNER OF AZ.
BROADENING OUT AM SATELLITE LOOPS ACROSS THE WESTERN CONUS...THE
UPPER PACIFIC TROUGH CIRCULATION AND STRONG JET WINDS ARE CLEARLY
EVIDENT OFF THE PAC NW COAST. FURTHER TO THE SOUTH ACROSS THE GREAT
BASIN AND SOUTHWEST SOMEWHAT DRIER ML TO UL CONDITIONS EVIDENT ON
WATER VAPOR...WITH VERY DRY AIR OFF THE SO CAL/NORTHERN BAJA COAST
AND SOMEWHAT STEADY STATE MONSOONAL/TROPICAL AIRMASS OVER NORTHERN
MEXICO. GIVEN THE CLEAR SKIES AND SLIGHTLY DRIER DEWPOINT READINGS
ACROSS THE AREA...AVERAGING 5 TO 10 DEGREES DRIER OVER THIS
MORNING`S HOURS AS COMPARED TO FRIDAY...TEMPERATURES ARE ALREADY
RUNNING WARMER TODAY AND ON TARGET FOR THEIR WELL-ABOVE NORMAL
READINGS AT OR ABOVE THE 110F MARK.
FROM A CONVECTIVE SET-UP TODAY...NO EASILY DISCERNIBLE INVERTED
TROUGH OR STORM MCVS EVIDENT ON THE AM SAT LOOPS. ML AND UL HIGH
CENTERS GENERALLY OFF TO OUR SOUTH RESULTING IN RATHER CHAOTIC BUT
LIGHT FLOW FROM 500MB ON UPWARD. 12Z RAOBS AND ANALYSIS POINT TO A
VERY WEAK WAVE IN THE 500MB/400MB HEIGHT FIELD OVER CENTRAL AZ WITH
FLOW EVENTUALLY TRANSITIONING SOUTHERLY THROUGH THE MIDDAY AND
EVENING HOURS. MODEL STREAMLINE FORECASTS ADVERTISE BROAD AREA OF
UPPER DIFLUENCE PERSISTING FOR SEVERAL HOURS ACROSS PIMA COUNTY AND
SOUTHEASTERN AZ. NAM/GFS 500/400MB STREAMLINES DO SPIN UP SOME
ANTICYCLONIC CIRCULATION OVER CENTRAL AZ DURING MIDDAY BUT
EVENTUALLY ERODE THAT AWAY BY THE AFTERNOON WHILE CREATING SOME
DIFLUENT POCKETS THAT COULD AIDE STORM DEVELOPMENT INTO THE AFTN
OVER THE SOUTH-CENTRAL AZ DESERTS INCLUDING PHOENIX. WEAK MID-LEVEL
STEERING FLOW AND STILL FAVORABLE AIRMASS...WITH AREA PWATS RANGING
FROM 1.25 TO 1.5 INCHES...WILL GENERALLY LEAD TO ISO TO SCT SLOW
MOVING STORMS OVER THE HIGHER ELEVATIONS AND MOUNTAINOUS
TERRAIN...LEAVING THE LOWER DESERT LOCALES AT THE MERCY OF THE
TYPICAL OUTFLOW INTERACTION AND INTERSECTIONS FOR OUR STORM
DEVELOPMENT. LATEST HI-RES FCSTS POINT TO STORMS ON THE SOUTHERN
AND NORTHEASTERN PHX PERIPHERY BY THE AFTN WITH POTENTIAL OUTFLOW
INTRUSIONS AND SUBSEQUENT STORM DEVELOPMENT ACROSS THE PHX METRO
SOMETIME AROUND OR AFTER 5PM LOCAL OR 30/00Z. ONLY MINOR UPDATES
TO THE POP...WEATHER...SKY GRIDS THIS AM TO BLEND IN SOME OF THE
12Z GUIDANCE AND MATCH CURRENT CONDITIONS.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 305 AM MST/PDT...
A STRONG UPPER LEVEL TROF CURRENTLY SPINNING OFF THE
PAC NW COAST HAS KEPT THE DOWNSTREAM UPPER RIDGE PUMPED UP OVER THE
DESERT SOUTHWEST...WITH H5 VALUES AROUND 593DM ACROSS ARIZONA PER
THE LATEST PLOT DATA. THE HIGH HEIGHTS ALOFT CONTINUED TO PRODUCE
HOT WEATHER ACROSS THE LOWER DESERTS WITH PHOENIX REACHING 109
YESTERDAY AND YUMA HITTING 111. LITTLE CHANGE IN THE PATTERN IS
EXPECTED TODAY AND CONTINUED HOT WEATHER IS ON TAP FOR THE LOWER
DESERTS...IN FACT PHOENIX IS EXPECTED TO REACH 110 TODAY WITH 110
PLUS READINGS OVER THE HOTTER WESTERN DESERTS. TEMPERATURES TODAY
WILL BE VERY CLOSE TO EXCESSIVE HEAT WARNING LEVELS.
WITH THE TROFFING SITTING OFF THE WEST COAST AND THE RIDGE PARKED
FIRMLY OVERHEAD...STEERING FLOW IS EITHER WEAK AND NONDESCRIPT OR
WEAK SOUTHERLY. PLENTY OF MOISTURE CONTINUES TO FLOW NORTH THRU
CENTRAL AND EASTERN ARIZONA WITH PWAT VALUES BETWEEN 1.25 AND 1.5
INCHES...AND SURFACE DEWPOINTS REMAIN HIGH AS WELL. AT 2 AM MOST OF
THE LOWER DESERTS RANGED FROM THE MID 50S TO THE MID 60S. EAST OF
THE LOWER COLORADO RIVER TODAY THERE WILL BE SUFFICIENT MOISTURE...
MLCAPE AND DAYTIME HEATING TO KEEP A THREAT GOING FOR AFTERNOON AND
EVENING STORMS...AND IN FACT SEVERAL LOCAL MESOSCALE MODELS
INCLUDING THE HRRR CALL FOR CONVECTION BREAKING OUT THIS AFTERNOON
OVER THE CENTRAL DESERTS...INCLUDING THE GREATER PHOENIX AREA...AND
PERSISTING INTO THE NIGHTTIME HOURS. POPS HAVE BEEN RAISED EAST OF
THE LOWER COLORADO RIVER INTO THE 15-20 PERCENT BALLPARK WITH
CHANCES FORECAST IN THE HIGHER TERRAIN EAST OF PHOENIX.
ON SUNDAY SIGNIFICANT SHORTWAVE ENERGY IS FORECAST TO MOVE INLAND
OVER THE PAC NORTHWEST AND IN RESPONSE FLOW OVER THE DESERT
SOUTHWEST AND ARIZONA BECOMES INCREASINGLY SOUTHWESTERLY. HEIGHTS
ALOFT FALL SLIGHTLY AND TEMPS SHOULD COOL A FEW DEGREES BUT THEY
WILL REMAIN WELL ABOVE NORMAL. THE FLOW WILL START TO SHIFT THE
DEEPER MOISTURE FURTHER TO THE EAST...BUT THERE WILL BE SUFFICIENT
MOISTURE AND INSTABILITY TO KEEP THE THREAT GOING FOR AFTN/EVE STORMS
ACROSS SOUTH CENTRAL ARIZONA. POPS WILL BE SIMILAR TO TODAY...BUT
SLIGHTLY LOWER WEST OF MARICOPA COUNTY.
GFS AND ECMWF OPERATIONAL RUNS AS WELL AS ENSEMBLE GUIDANCE CONTINUE
TO CALL FOR A GRADUAL DRYING AND COOLING TREND TO OCCUR OVER THE
ENTIRE WORK WEEK NEXT WEEK...AS TROFFING ALOFT INITIALLY DEVELOPS
ALONG THE WEST COAST AND PLACES A DRYING SOUTHWEST FLOW ALOFT ACROSS
SERN CALIFORNIA AND ARIZONA. AS THE WEEK PROGRESSES THE TROFFING
STARTS TO PUSH INLAND AND AS THIS HAPPENS TEMPERATURES WILL COOL
DOWN TO NEAR SEASONAL NORMALS. MONDAY INTO TUESDAY THE TROF AXIS
REMAINS ALONG THE WEST COAST...AND FLOW IS NOT SUFFICIENT TO
COMPLETELY SCOUR OUT THE MOISTURE OVER ALL OF SOUTH CENTRAL AZ. FOR
THE MOST PART THE THREAT OF AFTERNOON AND EVENING STORMS WILL BE
CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX BUT CHANCES IN THE
GREATER PHOENIX AREA WILL CERTAINLY NOT BE ZERO...THEY WILL HOVER IN
THE 5 TO 10 PERCENT BALLPARK. FOR THE LATTER HALF OF THE WORKWEEK AS
THE TROF AXIS SHIFTS INLAND AND SOUTHWEST FLOW ALOFT BECOMES
STRONGER...MOISTURE WILL BE PUSHED OFF TO THE EAST AND EVENTUALLY
ANY THREAT FOR STORMS WILL FOCUS OVER HIGHER TERRAIN AREAS TO THE
EAST OF GLOBE WITH SKIES IN THE GREATER PHOENIX AREA MOSTLY SUNNY
EACH DAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...
EASTERLY FLOW ACROSS THE PHX AREA WILL CONTINUE INTO THE MID
AFTERNOON AS WESTERLY WINDS WILL BE A LITTLE SLOW TO
DEVELOP...LIKELY AFTER 22Z. ENOUGH MOISTURE REMAINS FOR SOME
SHOWERS/STORMS TO DEVELOP OVER THE MTNS OF ARIZONA...INCLUDING WEST
AND SOUTH OF PHX WHICH MAY IMPACT ARRIVAL/DEPARTURE ROUTES.
POSSIBLE...THOUGH NOT ENOUGH TO EXPLICITLY PUT IN TAFS...OF OUTFLOW
COMING IN THIS EVENING PRODUCING SOME BLDU AND PERHAPS A FEW
SHOWERS/STORMS IN THE PHX AREA ITSELF.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WIND PATTERNS WITH LITTLE CLOUD COVER EXPECTED. FEW
STORMS BETWEEN KBLH-KPHX-KNYL BETWEEN 19Z-01Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER... MONDAY THROUGH FRIDAY... OVERALL THE WEATHER
PATTERN WILL BE ON A GENTLE COOLING AND DRYING TREND. FOR MUCH OF
THE WEEK...ANY RAIN CHANCES WILL REMAIN OVER THE HIGHER ELEVATIONS
OF EASTERN ARIZONA. NO SIGNIFICANT WINDS THOUGH THE AFTERNOONS MAY
BE JUST A BIT BREEZIER THAN USUAL.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...NOLTE
PREVIOUS DISCUSSION...CB
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1048 AM PDT SAT AUG 29 2015
.SYNOPSIS...MUCH COOLER WEATHER IS FORECAST FOR THIS WEEKEND INTO
NEXT WEEK. OUTSIDE OF A SLIGHT CHANCE FOR RAIN ALONG THE SONOMA
COAST THIS MORNING...DRY WEATHER IS EXPECTED.
&&
.DISCUSSION...AS OF 09:10 AM PDT SATURDAY...A FRONTAL BOUNDARY
THAT BROUGHT LIGHT PRECIPITATION TO A GOOD PORTION OF THE NORTH
BAY THIS MORNING CONTINUES TO PUSH INLAND. MANY AREAS IN THIS
REGION PICKED UP A FEW HUNDREDTHS OF AN INCH...WHILE DRIER
CONDITIONS PERSIST SOUTH OF THE SAN FRANCISCO BAY AREA. ONCE THIS
BOUNDARY PUSHES FURTHER INLAND LATER THIS MORNING...CHANCES OF
PRECIPITATION WILL DIMINISH. TEMPERATURES REGION-WIDE WILL ALSO BE
MUCH COOLER TODAY COMPARED TO THE PAST FEW DAYS GIVEN THE COOLER
AIR MASS ASSOCIATED WITH THIS FRONTAL PASSAGE. MANY SPOTS WILL BE
A GOOD 10 TO 15 DEGREES COOLER THIS AFTERNOON. NO CHANGES ARE
NEEDED TO THE ONGOING FORECAST AT THIS TIME.
&&
.UPDATE...AS OF 5:40 AM PDT SATURDAY...RADAR CONTINUES TO SHOW A
LACK OF ANY RADAR RETURNS ACROSS THE NORTH BAY OR COASTAL WATERS
AND WITH THE HRRR NOW GREATLY BACKING OFF ON RAINFALL DECIDED TO
REMOVE MENTION OF RAIN FOR MOST OF OUR AREA. DID KEEP A SLIGHT
CHANCE FOR COASTAL SONOMA COUNTY IN CASE SOME LIGHT RAIN FINALLY
HITS THAT AREA. FOR THE REST OF THE CWA...NOW APPEARS THAT WE WILL
STAY DRY THROUGH THE DAY.
&&
.PREV DISCUSSION...AS OF 3:20 AM PDT SATURDAY...COASTAL RADARS
HAVE PICKED UP ECHOES THROUGH THE OVERNIGHT HOURS ALTHOUGH TO THIS
POINT VIRTUALLY ALL HAVE BEEN NORTH OF OUR CWA. LATEST RUN OF THE
HRRR CONTINUES TO BE IN GOOD AGREEMENT WITH PREVIOUS RUNS AND
BRINGS LIGHT RAIN ACROSS THE NORTH BAY THIS MORNING AND
POTENTIALLY DOWN INTO THE SF BAY AREA AS A COLD FRONT MOVES
ACROSS. WILL BE INTERESTING TO SEE HOW WELL THE HRRR ENDS UP
DOING. EARLIER THIS YEAR WE FOUND THAT IN SOME CASES IT NAILED THE
RAINFALL FOR THE DAY WHILE OTHER TIMES IT WOULD BRING RAIN ACROSS
WHILE THE GROUND TRUTH WAS FAR DRIER.
MORE NOTABLE THAN THE POTENTIAL FOR LIGHT RAIN WILL BE MUCH
COOLER WEATHER THIS WEEKEND AS THE MARINE LAYER DEEPENS WHILE THE
FLOW AT THE SURFACE BECOMES MORE WESTERLY. AT THE SAME TIME THE
STRONG RIDGE OF HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS WILL
PROGRESS TO THE EAST AS THE LONGWAVE TROF ADVANCES TO THE COAST.
INLAND SPOTS WILL GENERALLY SEE THE BIGGEST DROPS COMPARED TO
YESTERDAY WITH HIGHS AS MUCH AS 15 TO 20 DEGREES COOLER. COASTAL
TEMPS WILL GENERALLY BE 5 TO 10 DEGREES COOLER. THE FRONTAL
PASSAGE WILL ALSO TRIGGER BREEZY CONDITIONS WITH LOCALLY GUSTY
WESTERLY WINDS.
SYNOPTICALLY THE NEXT 10 DAYS ARE SHAPING UP WITH THE LONGWAVE
PATTERN FAIRLY STAGNANT...TROF OVER THE WEST WITH A RIDGE TO THE
EAST. THIS WILL TRANSLATE TO TEMPS AT OR BELOW NORMAL. ANY
RAINFALL IS EXPECTED TO FALL NORTH OUR OUR REGION. FOR WHAT IT`S
WORTH...THE 16 DAY GFS SHOWS DRY WEATHER AFTER TODAY FOR OUR
ENTIRE AREA.
&&
.AVIATION...AS OF 10:45 AM PDT SATURDAY... CHAOTIC SKIES WITH
VARYING AND INTERMITTENT FLIGHT RULES THIS MORNING. LATEST METARS
REPORTING MIXING OUT AND LIFTING OF CIGS THROUGHOUT THE LOWER
LAYERS... WHICH WILL TRANSITIONS CIGS FROM MVFR TO VFR THROUGH THE
NEXT HOUR OR TWO. SKIES WILL CLEAR BEHIND THE FRONT... WHICH IS
PUSHING INTO THE INLAND NORTHERN BAY AREA NOW. INCREASING CLOUDS
FOR THE SOUTHERN TAF SITES...INC KMRY...KSNS...KWVI AS FRONT
APPROACHES... HOWEVER EXPECTING VFR FOR THESE SITES FOR REMAINDER
OF DAYLIGHT. RETURN OF MARINE LAYER TONIGHT WILL BE SLIGHTLY LATER
THAN AVERAGE... AND WITH CIGS LOWER THAN NORMAL ON AVERAGE. FOR
TONIGHT... MVFR CIGS EXPECTED FOR BAY AREA... IFR CIGS FOR
MONTEREY BAY AREA. OVERALL CONFIDENCE MODERATE.
VICINITY OF KSFO...GRADUALLY IMPROVING CIGS... CLEARING RAPIDLY
BEHIND FRONT. CLEARING CIGS NO LATER THAN 20Z. LAYER RETURNS AFTER
06-8Z TONIGHT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO... SLIGHTLY LATER CLEARING.
POSBL AS LATE AS 21Z.
MONTEREY BAY AREA TERMINALS... CHAOTIC SKIES THROUGH THE DAY AS
FRONT APPROACHES... HOWEVER CIGS SHOULD PREDOMINATELY BE VFR WITH
SOME BRIEF MVFR CIGS (ABOVE 2000 FT) POSBL THROUGH THE DAY. MARINE
LAYER RETURNS BEHIND THE FRONT.
&&
.BEACHES...AS OF 10:45 AM PDT SATURDAY...A LONG PERIOD WEST SWELL
HAS ARRIVED AND WILL CONTINUE TO ADVANCE ON WEST FACING BEACHES
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THESE LONG PERIOD
SWELLS CAN PRODUCE HAZARDOUS RIP CURRENTS THAT CAN QUICKLY PULL
SWIMMERS OUT TO SEA. THE HIGHEST RISK OF HAZARDOUS CONDITIONS WILL
BE THIS WEEKEND WHEN ONSHORE WINDS WEAKEN AND THE PERIOD INCREASES
FROM 15 TO 18 SECONDS. SWIMMERS CAUGHT IN A RIP CURRENT SHOULD
SWIM PARALLEL TO THE COAST TO ESCAPE THE RIP CURRENTS.
&&
.MARINE...AS OF 10:41 AM PDT SATURDAY...FOR TODAY... A FRONTAL
SYSTEM WILL MOVE THROUGH THE AREA. NORTHWEST WINDS WILL INCREASE
IN THE SOUTHERN WATERS THIS AFTERNOON AND OVER THE NORTHERN WATERS
SUNDAY BEHIND THE FRONT. ADDITIONALLY... A LONG PERIOD WEST SWELL
CONTINUES TO MOVE THROUGH THE REGION INTO EARLY NEXT WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 PM
&&
$$
PUBLIC FORECAST: RGASS/BELL
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
916 AM PDT SAT AUG 29 2015
.SYNOPSIS...MUCH COOLER WEATHER IS FORECAST FOR THIS WEEKEND INTO
NEXT WEEK. OUTSIDE OF A SLIGHT CHANCE FOR RAIN ALONG THE SONOMA
COAST THIS MORNING...DRY WEATHER IS EXPECTED.
&&
.DISCUSSION...AS OF 09:10 AM PDT SATURDAY...A FRONTAL BOUNDARY
THAT BROUGHT LIGHT PRECIPITATION TO A GOOD PORTION OF THE NORTH
BAY THIS MORNING CONTINUES TO PUSH INLAND. MANY AREAS IN THIS
REGION PICKED UP A FEW HUNDREDTHS OF AN INCH...WHILE DRIER
CONDITIONS PERSIST SOUTH OF THE SAN FRANCISCO BAY AREA. ONCE THIS
BOUNDARY PUSHES FURTHER INLAND LATER THIS MORNING...CHANCES OF
PRECIPITATION WILL DIMINISH. TEMPERATURES REGION-WIDE WILL ALSO BE
MUCH COOLER TODAY COMPARED TO THE PAST FEW DAYS GIVEN THE COOLER
AIR MASS ASSOCIATED WITH THIS FRONTAL PASSAGE. MANY SPOTS WILL BE
A GOOD 10 TO 15 DEGREES COOLER THIS AFTERNOON. NO CHANGES ARE
NEEDED TO THE ONGOING FORECAST AT THIS TIME.
&&
.UPDATE...AS OF 5:40 AM PDT SATURDAY...RADAR CONTINUES TO SHOW A
LACK OF ANY RADAR RETURNS ACROSS THE NORTH BAY OR COASTAL WATERS
AND WITH THE HRRR NOW GREATLY BACKING OFF ON RAINFALL DECIDED TO
REMOVE MENTION OF RAIN FOR MOST OF OUR AREA. DID KEEP A SLIGHT
CHANCE FOR COASTAL SONOMA COUNTY IN CASE SOME LIGHT RAIN FINALLY
HITS THAT AREA. FOR THE REST OF THE CWA...NOW APPEARS THAT WE WILL
STAY DRY THROUGH THE DAY.
&&
.PREV DISCUSSION...AS OF 3:20 AM PDT SATURDAY...COASTAL RADARS
HAVE PICKED UP ECHOES THROUGH THE OVERNIGHT HOURS ALTHOUGH TO THIS
POINT VIRTUALLY ALL HAVE BEEN NORTH OF OUR CWA. LATEST RUN OF THE
HRRR CONTINUES TO BE IN GOOD AGREEMENT WITH PREVIOUS RUNS AND
BRINGS LIGHT RAIN ACROSS THE NORTH BAY THIS MORNING AND
POTENTIALLY DOWN INTO THE SF BAY AREA AS A COLD FRONT MOVES
ACROSS. WILL BE INTERESTING TO SEE HOW WELL THE HRRR ENDS UP
DOING. EARLIER THIS YEAR WE FOUND THAT IN SOME CASES IT NAILED THE
RAINFALL FOR THE DAY WHILE OTHER TIMES IT WOULD BRING RAIN ACROSS
WHILE THE GROUND TRUTH WAS FAR DRIER.
MORE NOTABLE THAN THE POTENTIAL FOR LIGHT RAIN WILL BE MUCH
COOLER WEATHER THIS WEEKEND AS THE MARINE LAYER DEEPENS WHILE THE
FLOW AT THE SURFACE BECOMES MORE WESTERLY. AT THE SAME TIME THE
STRONG RIDGE OF HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS WILL
PROGRESS TO THE EAST AS THE LONGWAVE TROF ADVANCES TO THE COAST.
INLAND SPOTS WILL GENERALLY SEE THE BIGGEST DROPS COMPARED TO
YESTERDAY WITH HIGHS AS MUCH AS 15 TO 20 DEGREES COOLER. COASTAL
TEMPS WILL GENERALLY BE 5 TO 10 DEGREES COOLER. THE FRONTAL
PASSAGE WILL ALSO TRIGGER BREEZY CONDITIONS WITH LOCALLY GUSTY
WESTERLY WINDS.
SYNOPTICALLY THE NEXT 10 DAYS ARE SHAPING UP WITH THE LONGWAVE
PATTERN FAIRLY STAGNANT...TROF OVER THE WEST WITH A RIDGE TO THE
EAST. THIS WILL TRANSLATE TO TEMPS AT OR BELOW NORMAL. ANY
RAINFALL IS EXPECTED TO FALL NORTH OUR OUR REGION. FOR WHAT IT`S
WORTH...THE 16 DAY GFS SHOWS DRY WEATHER AFTER TODAY FOR OUR
ENTIRE AREA.
&&
.AVIATION...AS OF 4:45 AM PDT SATURDAY...LOW CLOUDS THAT CAME IN
EARLIER THIS EVENING IS MIXING OUT AHEAD OF AN APPROACHING FRONTAL
SYSTEM AS SEVERAL AREA METARS ARE CURRENTLY REPORTING SCT CLOUDS.
SATELLITE IMAGE SHOWS LOW CLOUDS ASSOCIATED WITH THE FRONT
JUST OFFSHORE. THUS WIDESPREAD CIGS WILL RETURN TO THE AREA AFTER
14Z BUT CIGS WILL BE HIGHER AT OR ABOVE 1500 FEET. CLEARING TAKES
PLACE BY AFTERNOON AS THE BACK EDGE OF THE FRONT MOVES THROUGH.
BREEZY POST-FRONTAL WEST WINDS POSSIBLE IN THE AFTERNOON.
VICINITY OF KSFO...MVFR CIGS BY 14Z CLEARING BY 21Z.
CONFIDENCE IS MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...IFR CIGS WILL LIFT TO MVFR CIGS
AFTER 14-15Z. CIGS ARE EXPECTED TO FURTHER LIFT AND MIX OUT BY
AROUND 18Z. CONFIDENCE IS MODERATE.
&&
.BEACHES...AS OF 4:30 AM PDT SATURDAY...A LONG PERIOD WEST SWELL
HAS ARRIVED AND WILL CONTINUE TO ADVANCE ON WEST FACING BEACHES
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THESE LONG PERIOD
SWELLS CAN PRODUCE HAZARDOUS RIP CURRENTS THAT CAN QUICKLY PULL
SWIMMERS OUT TO SEA. THE HIGHEST RISK OF HAZARDOUS CONDITIONS WILL
BE THIS WEEKEND WHEN ONSHORE WINDS WEAKEN AND THE PERIOD INCREASES
FROM 15 TO 18 SECONDS. SWIMMERS CAUGHT IN A RIP CURRENT SHOULD
SWIM PARALLEL TO THE COAST TO ESCAPE THE RIP CURRENTS.
&&
.MARINE...AS OF 09:10 AM PDT SATURDAY...FOR TODAY... A FRONTAL
SYSTEM WILL MOVE THROUGH THE AREA. NORTHWEST WINDS WILL INCREASE
IN THE SOUTHERN WATERS THIS AFTERNOON AND OVER THE NORTHERN WATERS
SUNDAY BEHIND THE FRONT. ADDITIONALLY... A LONG PERIOD WEST SWELL
CONTINUES TO MOVE THROUGH THE REGION INTO EARLY NEXT WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 PM
&&
$$
PUBLIC FORECAST: RGASS/BELL
AVIATION: W PI
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS ALBANY NY
415 PM EDT SAT AUG 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER NEW YORK AND NEW ENGLAND
THROUGH MOST OF THE WEEKEND WITH TRANQUIL WEATHER. A WEAK WARM FRONT
WILL SPREAD SOME CLOUDS IN TONIGHT INTO EARLY SUNDAY AND PERHAPS
TRIGGER A STRAY SHOWER OR THUNDERSTORM BY SUNDAY AFTERNOON.
THEN...THE HUMIDITY AND HEAT WILL INCREASE AS WE HEAD INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 415 PM EDT...ANOTHER NICE DAY AROUND THE REGION
ALTHOUGH NOT AS CLEAR AS PREVIOUS DAYS. THERE WERE SOME CU AND CI.
HOWEVER...BASED ON SATELLITE PICTURES AND APPROXIMATE TRAJECTORIES...
THINKING THERE WAS ACTUALLY SOME SMOKE ALOFT FROM THE MASSIVE FOREST FIRES
ACROSS THE NORTHWEST.
IT WILL BE INTERESTING TO SEE IF THIS SMOKE HAS ANY BEARING ON
HIGH/LOW TEMPERATURES ON THE DAYS TO COME...BUT EITHER WAY...ITS
EFFECT WILL BE MINIMAL AT BEST.
OTHERWISE...IT WILL BE DRY THROUGH EVENINGWITH ANY SHOWERS...
THE RESULT OF A VERY WEAK SHORT WAVE WELL TO THE NORTH OF CANADIAN/US BORDER...
REMAINING MOSTLY NORTH OF THE REGION.
TEMPERATURES WILL TOP OUT 75-80 HIGHLANDS...80-85 VALLEYS (WARMEST IN THE
MID HUDSON VALLEY). DEWPOINTS HAVE CREPT UP A LITTLE COMPARED TO YESTERDAY...
BUT GENERALLY WERE IN THE UPPER 50S...STILL ON THE COMFORTABLE SIDE.
A FEW LIGHT SHOWERS MIGHT BRUSH NORTHERN HERKIMER COUNTY. (IT SHOULD BE NOTED
THE LATEST HRRR ACTUALLY INDICATED SOME SHOWERS WORKING DOWN THE MOHAWK VALLEY
LATER THIS EVENING). HOWEVER...AT THIS TIME...WE ARE NOT BUYING THIS SOLUTION
SINCE HIGH PRESSURE AND SUBSIDENCE REMAINED OVERHEAD.
WE DO THINK THERE WILL BE A GENERALLY INCREASE IN CLOUDS THIS EVENING AND
ESPECIALLY OVERNIGHT...AHEAD OF AN ADVANCING WARM FRONT. IF THIS IS THE CASE...
OVERNIGHT TEMPERATURES WILL BE MILDER THAN LAST NIGHT...THAT IS ACTUALLY
HOW WE SKETCHED IT OUT IN OUR FORECAST PACKAGE. MOST AREAS WILL RANGE FROM
THE MID 50S TO LOWER 60S TONIGHT.
A SOUTH WIND AROUND 10 MPH...WILL BECOME LIGHT AND VARIABLE TONIGHT.
DUE TO MORE CLOUDS THAN PERHAPS PREVIOUS ANTICIPATED WE BACKED OFF A LITTLE
ON OUR THINKING OF FOG FOR TONIGHT. FOR NOW...WE CONFIDE IT TO THE MOST
PREVALENT VALLEYS AND JUST CALL IT PATCHY FOG.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL CONTINUE TO "RULE THE ROOST" FOR AT LEAST THE NEXT SEVERAL
DAYS TO COME. INITIALLY STRONGER AT THE SURFACE...IT WILL ULTIMATELY
STRENGTHEN ALOFT AS WELL AS OFFSHORE THROUGH EARLY IN THE WEEK.
A SOUTHERLY FLOW OF ULTIMATELY MORE HUMID AIR WILL OVERSPREAD THE
REGION. THE LEADING EDGE OF THIS MORE HUMID AIR...A WARM FRONT...
WILL ADVANCE TO OUR REGION EARLY SUNDAY AND TEND TO WASH OUT. STILL...
THIS WILL LEAVE SOME RESIDUAL (MOSTLY HIGH CLOUDS BEHIND). SUNDAY COULD
START OUT RATHER CLOUDY WITH PERHAPS A SPRINKLE OR TWO (NOT IN THE GRIDS
AT THIS TIME).
WE THINK SOME SUNSHINE WILL INCREASE DURING SUNDAY AFTERNOON BUT AGAIN
ANY SMOKE ALOFT COULD HAVE A BEARING ON HUGH TEMPERATURES. EITHER WAY...
IT WILL FEEL MORE HUMID BY AFTERNOON WITH DEWPOINTS GETTING UP INTO THE
LOWER END OF THE 60S...EXCEPT EVEN HIGHER ACROSS OUR SOUTHERN ZONES.
WITH SOME SUNSHINE ANTICIPATED WE LEANED WITH THE WARM MAV
GUIDANCE GIVING US HIGH TEMPERATURES LOWER TO MID 80S IN THE VALLEYS...75-80
HIGHER TERRAIN.
WHILE CONDITIONS WILL NOT BE IDEAL FOR CONVECTION ON SUNDAY AFTERNOON...
THERE WILL BE SOME INSTABILITY...ESPECIALLY SOUTH OF I-90
WHERE SBCAPES COULD REACH 500 J/KG. ALSO THERE WILL BE SOME
SORT OF BOUNDARY (DISSIPATING WARM FRONT) TO ACT AS A FOCUS FOR
CONVECTION. THE ABOVE ALONG WITH INCREASING LOW LEVEL MOISTURE WAS
ENOUGH JUSTIFICATION TO RE-INTRODUCE A 20 POP FOR SHOWERS/THUNDER ON
SUNDAY AFTERNOON. MID LEVEL LAPSES RATE LOOK TO REMAIN MEAGER AT ONLY
AROUND 5.5 C/KM) AND THE WIND FIELD WEAK SO
NO SEVERE THUNDERSTORMS (OR EVEN STRONG FOR THAT MATTER) EXPECTED.
SUNDAY NIGHT SHOULD BE CLEAR TO PARTLY CLOUDY WITH LOWS FROM THE MID 50S TO THE MID
60S...WARMEST IN THE CAPITAL REGION. SINCE THERE LOOK TO BE LESS CLOUDS AND
LITTLE OR NO WIND...FOG MIGHT BE A BETTER BET. FOR NOW THOUGH WE JUST KEPT PATHCY FOG
IN THE CLIMATOLOGICALLY FAVORED REGIONS.
MONDAY LOOKS VERY WARM WITH A GOOD DEAL OF SUNSHINE...SCATTERED MIDDAY
AND AFTERNOON CU. H850 TEMPERATURES WILL BE AROUND +16C TRANSLATING HIGHS
INTO THE 80S (UPPER 80S CAPITAL REGION SOUTHWARD IN THE VALLEYS).
A LIGHT WIND WILL BECOME WEST TO SOUTHWEST 5-10 MPH.
DRY MONDAY NIGHT WITH LOWS GENERALLY IN THE 60S. THE SKY WILL AVERAGE PARTLY CLOUDY
WITH PERHAPS SOME VALLEY FOG (NOT IN THE GRIDS AT THIS TIME).
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A LARGE UPPER LEVEL RIDGE WILL DOMINATE THE WEATHER THROUGH MOST OF
THE EXTENDED PERIOD...ALLOWING FOR ABOVE NORMAL TEMPERATURES AND
MAINLY DRY WEATHER.
THE UPPER LEVEL RIDGE AXIS WILL BE CENTERED RIGHT THROUGH THE
NORTHEAST FOR TUESDAY INTO WEDNESDAY. 850 HPA AROUND 16-19 DEGREES C
WILL ALLOW FOR DAYTIME TEMPS WELL INTO THE 80S...WITH SOME LOW 90S
EVEN POSSIBLE FOR THE HUDSON VALLEY REGION. OVERNIGHT LOW WILL
MAINLY BE IN THE 60S. ALONG WITH THE WARM TEMPERATURES...IT WILL BE
FAIRLY MUGGY WITH DEWPOINTS INTO THE 60S. DRY WEATHER SHOULD BE IN
PLACE...ALTHOUGH CANNOT RULE OUT AN AFTERNOON SHOWER FOR THE
ADIRONDACKS FOR WED AFTN.
AN UPPER LEVEL DISTURBANCE WILL SLIDE ACROSS THE TOP OF THE RIDGE
ACROSS EASTERN CANADA FOR THURSDAY INTO FRIDAY. THIS FEATURE WILL
PROBABLY BE TOO FAR AWAY FROM OUR AREA TO HAVE A MAJOR IMPACT...BUT
IT COULD PUSH A BACKDOOR SFC BOUNDARY CLOSE ENOUGH TO THE AREA FROM
THE NORTH OR NORTHEAST TO ALLOW A STRAY SHOWER OR THUNDERSTORM TO
DEVELOP IN THE AFTN OR EVENING HOURS. OTHERWISE...DRY AND VERY WARM
WEATHER WILL CONTINUE...WITH HIGHS WELL INTO THE 80S EACH DAY...AND
OVERNIGHT LOWS MAINLY IN THE 60S.
WARM TEMPS WILL CONTINUE FOR THE WEEKEND AS WELL...WITH TEMPS
CONTINUING WELL ABOVE NORMAL. WILL CONTINUE TO FORECAST VALLEY HIGH
TEMPS IN THE MID TO UPPER 80S FOR SAT WITH THE UPPER LEVEL RIDGE
STILL IN PLACE OVER MUCH OF THE CENTRAL AND EASTERN US...WITH NO
PRECIP EXPECTED TO OCCUR.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
RIDGING WILL REMAIN ACROSS THE REGION...HOWEVER THE CENTER
OF THE HIGH WILL GRADUALLY SHIFT OFFSHORE INTO SUNDAY. IN THE
MEANTIME...A SHORT WAVE TROUGH OVER THE GREAT LAKES REGION
WILL MOVE EASTWARD AND DAMPEN OUT AS IT PASSES OVER EASTERN
CANADA.
LOOKING AT VFR CONDITIONS...THE EXCEPTION WILL BE AT KPSF WHERE
SOME FOG IS EXPECTED TO FORM OVERNIGHT AND MAY LOWER TO IFR FOR
A PERIOD LATE AT NIGHT. OTHERWISE...MUCH OF DIURNAL CUMULUS SHOULD
DISSIPATE THIS EVENING WITH HIGH LEVEL CIRRUS CLOUDS CONTINUING
TO STREAM OVERHEAD. MID LEVEL CLOUDS AREA ARE EXPECTED TO MOVE
IN OVERNIGHT. A CEILING OF AROUND 5K IS EXPECTED FOR SUNDAY MORNING.
LIGHT SOUTH TO SOUTHWEST WINDS WILL DIMINISH BECOMING CALM
OVERNIGHT WITH A SOUTHWEST TO WEST FLOW DEVELOPING SUNDAY.
HOWEVER THE FLOW SHOULD BE MORE SOUTHERLY AT KGFL.
OUTLOOK...
SUN NIGHT-WED NIGHT: PATCHY FOG LATE AT NIGHT/EARLY IN THE AM.
THU: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA
&&
.FIRE WEATHER...
NO SIGNIFICANT RAINFALL EXPECTED THROUGH THIS WEEK AS A LARGE HIGH
PRESSURE AREA...NOT ONLY AT THE SURFACE...BUT ALOFT...DOMINANTS
OUR WEATHER.
IN FACT...NOTHING MORE THAN A STRAY SHOWER OR THUNDERSTORM
IS EXPECTED WITH THE BEST CHANCES OF THAT SUNDAY AFTERNOON
AND AGAIN FRIDAY. EVEN THIS WOULD BE THE EXCEPTION THAN THE RULE.
EXPECT NORMAL DIURNAL TRENDS REGARDING THE RH...WITH FULL OR NEARLY
FULL RECOVERY EXPECTED EACH OVERNIGHT. DAYTIME RH VALUES WILL BE MODERATE
GENERALLY IN THE 40-60 PERCENT RANGE.
THE WIND EACH DAY WILL LIGHT AND VARIABLE...MAINLY UNDER 10 MPH.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT FIVE DAYS.
NO WIDESPREAD RAINFALL IS FORECAST TO FALL FOR AT LEAST THE NEXT
FIVE DAYS AS A RIDGE OF HIGH PRESSURE BUILDS IN.
RIVER LEVELS WILL CONTINUE TO RUN AT OR BELOW NORMAL LEVELS FOR
AUGUST...AND IF ANYTHING...MIGHT DROP A LITTLE MORE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...FRUGIS
AVIATION...IAA
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
410 PM EDT SAT AUG 29 2015
...HEAVY RAIN THREAT THROUGH MONDAY...
TONIGHT...SURFACE-850 MB SOUTHEAST WINDS WILL INCREASE TO 20-25
KNOTS AS THE REMNANT LOW PRESSURE TROUGH FROM ERIKA MOVES INTO THE
FLORIDA STRAITS. THIS WILL FAVOR CONVERGENCE LINES OFF THE BAHAMAS
AND SOME COASTAL CONVERGENCE. THEREFORE ONCE LINGERING DEBRIS
RAINFALL AND SCATTERED STORMS END THIS EVENING...THERE WILL BE A
GOOD CHANCE FOR SHOWERS AND STORMS ALONG THE COAST OVERNIGHT. THE
LATEST GFS SHOWS THE HIGHEST RAIN AMOUNTS ALONG THE TREASURE
COAST...WITH POPS 50-60 PERCENT AND WILL FOLLOW CLOSE TO MOS VALUES.
SUN...HIGH PRECIPITABLE WATER NEAR 2.25 INCHES WILL ENCOMPASS THE
AREA AS THE LOW PRESSURE TROUGH PUSHES INTO THE SOUTHEAST
GULF. INCREASED LOW LEVEL CONVERGENCE DUE TO THE TROUGH...COMBINED
WITH UPPER LEVEL DIVERGENCE DUE TO MID/UPPER LEVEL TROUGH IN THE
GULF....WILL PRODUCE VERY HIGH RAIN CHANCES AND A THREAT FOR HEAVY
RAIN. THIS IS EVIDENCED BY THE 12Z GFS POPS 80-100 PERCENT AND 12
HOUR QPF VALUES 2 INCHES OR GREATER. THINK THAT THE HEAVY RAIN
CHANCES WILL BE NEAR THE COAST IN THE MORNING THEN TRANSITION TO
THE INTERIOR IN THE AFTERNOON AS MODEST HEATING OCCURS THROUGH
LATE MORNING.
SUN NIGHT...WITH THE HIGH MOISTURE AND STILL BREEZY LOW LEVEL
WINDS...THE CHANCE FOR SHOWERS/STORMS WITH HEAVY RAIN WILL
CONTINUE QUITE HIGH AND HAVE KEPT PREVIOUS POPS WHICH WERE 60
PERCENT.
MON...THE GFS SHOWS SURFACE LOW PRESSURE TROUGH PUSHING FARTHER
OUT INTO THE GULF AROUND 86W. WHILE THE LOW LEVEL WINDS/CONVERGENCE
WILL WEAKEN UNDER THIS SCENARIO...AND UPPER LEVEL DIVERGENCE ALSO
DECREASES...HIGH PRECIPITABLE WATER 2.25 INCHES OR GREATER IS
FORECAST TO CONTINUE. THEREFORE LIKELY POPS INDICATED BY THE MOS
AND INCLUDED IN THE PREVIOUS FORECAST LOOK GOOD. THE THREAT OF
FOR HEAVY RAIN WILL CONTINUE. GFS MODEL AMOUNTS FOR THE SUN-MON
PERIOD ARE 1-3 INCHES AREAWIDE...WHICH LOOKS REASONABLE.
HOWEVER...WITH PRECIPITABLE WATER VALUES 2.25 INCHES THROUGH THE
PERIOD...LOCALLY HIGHER AMOUNTS 3-5 INCHES ARE CERTAINLY POSSIBLE.
TUE-FRI...REMNANT SURFACE TROUGH FROM ERIKA IS FORECAST TO MOVE
SLOWLY IN THE NORTHEAST GULF OF MEXICO OR GRADUALLY WASH OUT.
ATLANTIC SURFACE RIDGE SHOULD EXTEND NORTH OF THE REGION AND
CONTINUE A SOUTHEASTERLY WIND FLOW...WITH MORE TYPICAL LIGHTER
SPEEDS THOUGH. MOISTURE LOOKS ELEVATED WITH LAPSE RATES RATHER
AVERAGE. EXPECT A RETURN TO SCATTERED AFTERNOON/EVENING
SHOWERS/STORMS.
&&
.AVIATION...SCT TSRA FROM KMCO-KDED WILL MOVE WESTWARD INTO LATE
AFTERNOON WITH ADDITIONAL SHRA/TSRA EXPECTED TO DEVELOP FROM KLEE-
KISM INTO EARLY EVENING. HRRR INDICATES SOME CONVECTION MAY PUSH
BACK TO KSFB-KMCO CORRIDOR INTO LATE EVENING WITH MID LVL SW FLOW.
SCATTERED ATLC SHOWERS WILL INCREASE IN COVERAGE AND MOVE ONSHORE
FROM KMLB-KSUA OVERNIGHT WITH TEMPO SHRA EXPECTED FOR THE LATE NIGHT
HOURS PROGRESSING INTO THE INTERIOR BY LATE MORNING ON SUNDAY. MVFR
CIGS AND IFR VSBYS PSBL WITH +SHRA/+TSRA IN CONVECTION.
&&
.MARINE...
TONIGHT...PRESSURE GRADIENT WILL GRADUALLY TIGHTEN AS LOW
PRESSURE TROUGH FROM REMNANTS OF ERIKA LIFTS INTO THE FLORIDA
STRAITS. EAST/SOUTHEAST WINDS WILL INCREASE ENOUGH TONIGHT FOR
EXERCISE CAUTION CONDITIONS IN THE SOUTH. ELSEWHERE THERE WILL BE
MORE WIND CHOP SO CONDITIONS STARTING OUT SUNDAY LOOK POOR FOR
SMALL CRAFT OVER ALL OF THE WATERS.
SUN-MON...THE WEATHER CONDITIONS LOOK POOR WITH SCATTERED TO
NUMEROUS SHOWERS AND STORMS WITH GUSTY WINDS TO 30 KNOTS. OUTSIDE
THE CONVECTION...GRADIENT WILL SUPPORT EXERCISE CAUTION FROM ABOUT
THE CAPE SOUTH ON SUNDAY AND POSSIBLY INTO SUNDAY EVENING.
SOUTHEAST WINDS WILL DIMINISH TO 10-15 KNOTS LATE SUNDAY NIGHT AND
INTO MONDAY.
TUE-WED...HIGH PRESSURE RIDGE ALONG THE EASTERN SEABOARD WILL
CONTINUE TO PRODUCE A SOUTHEAST WIND FLOW BUT SPEEDS LOOK CLOSER
TO 10 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 77 86 76 86 / 30 70 60 70
MCO 76 89 75 89 / 30 70 50 70
MLB 78 87 77 88 / 30 80 60 70
VRB 78 88 77 88 / 40 80 60 70
LEE 76 92 75 89 / 30 70 40 60
SFB 76 88 75 89 / 30 70 50 70
ORL 76 88 75 88 / 30 70 50 70
FPR 78 89 77 89 / 40 80 60 70
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH MONDAY EVENING FOR COASTAL VOLUSIA COUNTY-
INDIAN RIVER-INLAND VOLUSIA COUNTY-MARTIN-NORTHERN BREVARD
COUNTY-NORTHERN LAKE COUNTY-OKEECHOBEE-ORANGE-OSCEOLA-
SEMINOLE-SOUTHERN BREVARD COUNTY-SOUTHERN LAKE COUNTY-ST.
LUCIE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
LONG TERM....SEDLOCK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
228 PM CDT SAT AUG 29 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 228 PM CDT SAT AUG 29 2015
LATEST SURFACE MAP SHOWING FRONTAL BOUNDARY ARCING FROM THE
NORTHEAST TIP OF ILLINOIS TO EAST CENTRAL IOWA...BEFORE EXTENDING
SOUTHWEST INTO SOUTHEAST KANSAS. PRECIPITATION HAS LARGELY REMAINED
LIGHT AND SCATTERED...AND HAS BEEN MOSTLY EAST OF I-55 THE LAST
SEVERAL HOURS. DECENT SLUG OF DRY AIR ALOFT SEEN ON WATER VAPOR
IMAGERY SOUTH OF A SHORTWAVE...WHICH IS CURRENTLY DROPPING INTO
SOUTHERN IOWA. SHORT-RANGE MODEL GUIDANCE IS HAVING A BIT OF
DIFFICULTY AS TO THE AMOUNT OF REDEVELOPMENT...BUT THE HRRR IS
PERFORMING HALFWAY DECENTLY AND CONTINUES TO SUGGEST MAINLY SCATTERED
SHOWERS. THUNDER HAS BEEN STAYING AWAY FROM OUR AREA SO FAR...AND
WHILE MESOANALYSIS SHOWS RESPECTABLE CAPE VALUES OF 1000-1500 J/KG
THIS AFTERNOON...MID LEVEL LAPSE RATES ARE FAIRLY MODEST. THEREFORE
WILL CONTINUE MENTION WITH ONLY ISOLATED THUNDERSTORMS THROUGH
TONIGHT...WITH THE THREAT DIMINISHING FROM NORTHWEST TO SOUTHEAST.
SOME CONCERNS LATER IN THE NIGHT WITH POTENTIAL FOR SOME FOG...
MAINLY ACROSS THE NORTHWEST CWA. STILL QUITE A BIT OF LOWER
STRATOCUMULUS ACROSS MOST OF IOWA AND WISCONSIN. LATEST RAP MODEL
GUIDANCE SUGGESTS THIS CONTRACTING SOME MORE OVER THE NEXT SEVERAL
HOURS...BEFORE SIGNIFICANTLY EXPANDING AGAIN THIS EVENING WITH HIGH
PRESSURE EXPANDING OVER THE MIDWEST. MUCH OF THE AREA UNDERNEATH
THIS HIGH SAW FROM 1 TO SEVERAL INCHES OF RAIN IN THE LAST COUPLE
DAYS...AND IS MOST FAVORED FOR DENSE FOG POTENTIAL. HOWEVER...THE
RAP SHOWS THE FOG FIELD OOZING SOUTHWARD AFTER MIDNIGHT...PERHAPS AS
FAR AS PEORIA. THAT AREA ALREADY HAD PATCHY FOG IN THE GRIDS...BUT
AM THINKING IT WILL BE A BIT MORE WIDESPREAD AND WILL GO WITH AREAS
OF FOG INSTEAD.
&&
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 228 PM CDT SAT AUG 29 2015
SHOWERS AND ISOLATED THUNDERSTORMS COULD LINGER IN THE SOUTHEASTERN
PART OF THE CWA SUNDAY MORNING BUT THEN SPREAD BACK WEST
SOME...COVERING THE EASTERN HALF OF THE CWA...MAINLY EAST OF I-55.
THIS SHOULD BE THE END OF THE PCPN AS THE FRONTAL SYSTEM DIMINISHES
OVER THE AREA REMAINDER OF THE WEEKEND. FOG AND LOWER CLOUDS WILL
SEEN THIS MORNING ALONG AND BEHIND THE FRONT...SO THINKING IS THAT
THE FOG WILL CONTINUE INTO THE FIRST FEW HOURS OF SUNDAY MORNING.
HAVE INCLUDED A SLIGHT CHANCE OF SHOWERS FOR SUNDAY NIGHT...AGAIN
MAINLY EAST OF I-55 TIL MIDNIGHT...AND THEN IN THE EXTREME SOUTHEAST
AFTER MIDNIGHT.
BEYOND THIS UPPER LEVEL RIDGING WILL BUILD INTO THE NORTHERN PLAINS
AND NORTHERN MISS VALLEY. ON THE SFC...HIGH PRESSURE RIDGING WILL
BUILD BACK TOWARD THE AREA FROM THE SOUTHEAST. THE COMBINATION OF
THE TWO SHOULD HELP TO KEEP THE AREA DRY THROUGH THE BEGINNING OF
THE WEEK. TEMPS WILL BE IN THE LOWER TO MIDDLE 80S TOMORROW...BUT
THEN WARM INTO THE MIDDLE TO UPPER 80S FOR MONDAY INTO TUESDAY.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY...THOUGH SOME OF THE
MODELS CONTINUE TO BRING SOME SPOTTY POPS IN THE AREA DUE TO
SOUTHERLY FLOW ON THE SFC. FOR NOW...WILL ONLY HAVE SLIGHT CHC POPS
FOR WED ACROSS AREAS ALONG AND NORTH OF I-74 AND EAST OF I-57.
REMAINDER OF THE WEEK WITH BE DRY...EVEN INTO THE BEGINNING OF THE
LABOR DAY WEEKEND. TEMPS WILL REMAIN WELL ABOVE NORMAL IN THE
EXTENDED PERIOD SO HEAT COULD BE AN ISSUE LATER...BUT DEWPOINTS WILL
REMAIN LOW SO HEAT INDEX VALUES ARE NOT EXPECTED TO GET OVER 100
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1230 PM CDT SAT AUG 29 2015
MAINLY VFR CONDITIONS OVER CENTRAL ILLINOIS AT MIDDAY...WITH A FEW
SHOWERS EAST OF KBMI-KSPI. WATCHING AN AREA OF MVFR/IFR CEILINGS
DROPPING DOWN FROM IOWA AND NORTHWEST ILLINOIS AHEAD OF AN UPPER
LEVEL DISTURBANCE...AND MVFR CEILINGS ARE NOT TOO FAR AWAY FROM
KPIA. SOME QUESTION AS TO THE SOUTHWARD PROGRESS...WITH THE RAP
MODEL KEEPING KPIA JUST ABOVE VFR LEVEL AND THE NAM DIPPING INTO
MVFR TERRITORY. HAVE INCLUDED SOME TEMPO CEILINGS AROUND 2500 FEET
THERE INITIALLY AND WILL CONTINUE TO EVALUATE THE PROGRESSION OVER
THE NEXT HOUR OR SO. MORE OF THE CONCERN FOR MVFR CONDITIONS OVER
CENTRAL ILLINOIS WILL BE AFTER 06Z...AS A WEAKENING FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY OVERHEAD. THE WIDESPREAD LOW
CLOUDS CURRENTLY TO OUR NORTHWEST ARE NOT LIKELY TO COMPLETELY
ERODE AND MORE LIKELY WOULD EXPAND OVERNIGHT...WITH THE RAP
HINTING AT POTENTIAL IFR/LIFR CONDITIONS AT KPIA LATE IN THE
NIGHT. HAVE HIT CONDITIONS AT KPIA THE HARDEST WITH TEMPO CEILINGS
AND VISIBILITIES THAT LOW...BUT MAINTAINED MVFR CONDITIONS
ELSEWHERE LATE TONIGHT INTO SUNDAY MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1230 PM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 1018 AM CDT SAT AUG 29 2015
SCATTERED SHOWERS CONTINUE TO PUSH ACROSS AREAS MAINLY EAST OF
I-55 THIS MORNING...WITH SOME SPRINKLES STARTING TO MOVE INTO
PARTS OF SOUTHEAST ILLINOIS AS WELL. MORNING SOUNDING FROM OUR
OFFICE SHOWED QUITE A BIT OF DRY AIR BELOW 12000 FEET...WHICH HAS
HELPED KEEP MOST OF THE RAIN LIMITED TO A FEW HUNDREDTHS OF
ACCUMULATION. LATEST RAP MODEL SOUNDINGS SHOW SOME MOISTENING OF
THE COLUMN DOWN TO ABOUT 5000 FEET OVER THE NEXT FEW HOURS...
HOWEVER SOME DRIER AIR IS ALSO EVIDENT ON WATER VAPOR IMAGERY
DROPPING SOUTHWARD AHEAD OF A FAST MOVING SHORTWAVE NOW LOCATED IN
NORTHERN IOWA...WHICH SHOULD KEEP THE NORTHWEST PART OF THE
FORECAST AREA DRY FOR A COUPLE MORE HOURS. HIGHER RESOLUTION MODEL
GUIDANCE SUGGESTS SOME ADDITIONAL SHOWERS SURGING NORTHEAST OUT OF
SOUTHERN MISSOURI AS A WEAK FRONTAL BOUNDARY PUSHES EAST. EARLIER
GRID UPDATES HAD INTRODUCED THIS TREND AND ONLY REQUIRED MINOR
UPDATES...MAINLY TO NUDGE TEMPERATURES DOWN A BIT.
&&
.SHORT TERM...(TODAY)
ISSUED AT 312 AM CDT SAT AUG 29 2015
07Z/2AM SURFACE ANALYSIS SHOWS A WEAK FRONTAL BOUNDARY EXTENDING
FROM WISCONSIN SOUTHWESTWARD TO THE TEXAS PANHANDLE. A PLUME OF
MAINLY MID-LEVEL MOISTURE AHEAD OF THE FRONT HAS RESULTED IN
SCATTERED LIGHT SHOWERS/SPRINKLES ACROSS THE WESTERN HALF OF THE
KILX CWA EARLY THIS MORNING. 00Z UPPER AIR SOUNDING SHOWED PLENTY
OF DRY AIR BELOW 850MB...SO PRECIP HAS BEEN HAVING A HARD TIME
REACHING THE GROUND IN MANY AREAS. FORECAST SOUNDINGS SHOW A
GRADUAL MOISTENING OF THE PROFILE TODAY...HOWEVER DEEP-LAYER
MOISTURE REMAINS LACKING. IN ADDITION...WIDESPREAD CLOUD COVER WILL
LIMIT INSTABILITY...WITH GFS SBCAPE VALUES ONLY REACHING THE 500 TO
1000J/KG RANGE. END RESULT WILL BE SCATTERED SHOWERS WITH PERHAPS A
RUMBLE OF THUNDER. THINK AREAL COVERAGE OF PRECIP WILL REMAIN
LOW...SO WILL ONLY CARRY 30-40 POPS. HIGH TEMPERATURES WILL RANGE
FROM THE UPPER 70S ALONG/NORTHWEST OF THE ILLINOIS RIVER...TO THE
MIDDLE 80S ALONG/SOUTHEAST OF I-70 WHERE CONDITIONS WILL REMAIN DRY
UNTIL A FEW SHOWERS ARRIVE DURING THE AFTERNOON.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 312 AM CDT SAT AUG 29 2015
FRONTAL BOUNDARY WILL SLOWLY PUSH EASTWARD LATER TODAY INTO
TONIGHT...WITH MODEL CONSENSUS SHOWING IT REACHING A CHICAGO TO
KIRKSVILLE LINE BY 12Z SUN. SCATTERED SHOWERS WILL BE ONGOING
AHEAD OF THE FRONT ACROSS MUCH OF THE AREA THIS EVENING...THEN
WILL SHIFT TO MAINLY LOCATIONS ALONG/EAST OF I-57 OVERNIGHT. MAIN
WEATHER CONCERN FOR TONIGHT WILL BE THE POTENTIAL FOR FOG ACROSS
THE W/NW CWA. AS THE SLOW-MOVING FRONT ARRIVES...WINDS WILL BECOME
LIGHT/VARIABLE ACROSS THIS AREA. DUE TO THE NEARLY CALM
WINDS...ADDED LOW-LEVEL MOISTURE FROM SHOWERS TODAY...AND PARTIAL
CLEARING LATE TONIGHT...THINK AT LEAST PATCHY FOG WILL FORM. BOTH
FORECAST SOUNDINGS AND NUMERIC GUIDANCE SUGGEST A REDUCTION IN
VSBY OVERNIGHT. CURRENT OBSERVATIONS IN THE VICINITY OF THE FRONT
ACROSS IOWA SHOW WIDESPREAD FOG...WITH A FEW VSBYS DOWN TO AROUND
1/4 MILE. THINK THIS SAME SCENARIO WILL UNFOLD FURTHER EAST
TONIGHT...SO HAVE INCLUDED PATCHY FOG IN THE FORECAST WEST OF I-55
AFTER MIDNIGHT.
THE FRONTAL BOUNDARY WILL SLOWLY DISSIPATE ON SUNDAY...HOWEVER
ENOUGH UPPER-LEVEL SUPPORT WILL PERSIST TO SUPPORT AT LEAST A
MENTION OF A FEW SHOWERS/THUNDERSTORMS. MOST MODELS PRODUCE LIGHT
QPF ACROSS NEARLY THE ENTIRE CWA AS THE BOUNDARY HAS SLOWED SLIGHTLY
FROM PREVIOUS RUNS. AS A RESULT...HAVE PULLED POPS FURTHER WEST TO
INCLUDE SLIGHT CHANCES AS FAR WEST AS THE ILLINOIS RIVER SUNDAY
AFTERNOON/EVENING.
AFTER THAT...THE REMAINDER OF THE EXTENDED LOOKS WARM AND DRY AS
UPPER-LEVEL RIDGING DOMINATES THE EASTERN CONUS THROUGH THE END OF
THE COMING WEEK. A SLIGHT WEAKNESS IN THE RIDGE APPEARS TO DEVELOP
ACROSS ILLINOIS INTO THE OHIO RIVER VALLEY...POTENTIALLY TRIGGERING
ISOLATED AFTERNOON/EVENING CONVECTION TUESDAY THROUGH FRIDAY.
HOWEVER...MID-LEVEL WARMING BENEATH THE RIDGE WILL LIKELY LEAD TO
CAPPING AND AN OVERALL SUPPRESSION OF CONVECTION. AS A
RESULT...WILL MAINTAIN A DRY FORECAST WITH HIGH TEMPERATURES
CLIMBING INTO THE UPPER 80S TO AROUND 90 DEGREES EACH DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1230 PM CDT SAT AUG 29 2015
MAINLY VFR CONDITIONS OVER CENTRAL ILLINOIS AT MIDDAY...WITH A FEW
SHOWERS EAST OF KBMI-KSPI. WATCHING AN AREA OF MVFR/IFR CEILINGS
DROPPING DOWN FROM IOWA AND NORTHWEST ILLINOIS AHEAD OF AN UPPER
LEVEL DISTURBANCE...AND MVFR CEILINGS ARE NOT TOO FAR AWAY FROM
KPIA. SOME QUESTION AS TO THE SOUTHWARD PROGRESS...WITH THE RAP
MODEL KEEPING KPIA JUST ABOVE VFR LEVEL AND THE NAM DIPPING INTO
MVFR TERRITORY. HAVE INCLUDED SOME TEMPO CEILINGS AROUND 2500 FEET
THERE INITIALLY AND WILL CONTINUE TO EVALUATE THE PROGRESSION OVER
THE NEXT HOUR OR SO. MORE OF THE CONCERN FOR MVFR CONDITIONS OVER
CENTRAL ILLINOIS WILL BE AFTER 06Z...AS A WEAKENING FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY OVERHEAD. THE WIDESPREAD LOW
CLOUDS CURRENTLY TO OUR NORTHWEST ARE NOT LIKELY TO COMPLETELY
ERODE AND MORE LIKELY WOULD EXPAND OVERNIGHT...WITH THE RAP
HINTING AT POTENTIAL IFR/LIFR CONDITIONS AT KPIA LATE IN THE
NIGHT. HAVE HIT CONDITIONS AT KPIA THE HARDEST WITH TEMPO CEILINGS
AND VISIBILITIES THAT LOW...BUT MAINTAINED MVFR CONDITIONS
ELSEWHERE LATE TONIGHT INTO SUNDAY MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1242 PM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 1032 AM CDT SAT AUG 29 2015
Upstream 12Z raob at Omaha indicate a 500-700 ft stratus deck
advecting south and southeast towards northeast Kansas. Current
indications from the latest RAP and HRRR forecast soundings
suggest the low level saturation at 2500 ft to persist through
late afternoon so have adjusted to mostly cloudy skies through
most of the day. Also lowered highs about 5-7 degrees to the upper
70s and lower 80s. Will continue to monitor trends, especially
over north central areas where earlier clearing will quickly warm
temps.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 231 AM CDT SAT AUG 29 2015
Early this morning an upper level trough extended from the northern
Great Lakes...southwest across northern MO into eastern KS. The
surface cold front was moving southeast of the CWA. A broad upper
level ridge was located across the west central US.
The upper trough will shear apart with the more amplified northern
branch moving east across the Great Lakes States. The southern
section of the H5 trough will dig south across northeast OK through
the day. The model forecast soundings show wrap around low-level
moisture will advect southeast across northeast and east central KS
this morning. The low clouds should increase towards sunrise across
the eastern half of the CWA. I cannot rule out a few sprinkles but
the stronger ascent for rain showers and thunderstorms will be east
and south of the CWA. The clouds will gradually erode from west to
east across northeast and east central KS through the late morning
and early afternoon hours. Skies will remain clear across the
western counties of the CWA and patchy fog may develop before
sunrise but should mix out by 8 AM. Most areas will become mostly
sunny during the mid afternoon hours, though a few more clouds may
continue across the southeast counties through the afternoon hours.
Highs will be in the lower 80s across most of the CWA. The western
counties will receive more insolation and may reach into the mid 80s
for afternoon highs.
Tonight...The H5 trough digging south-southwest across east central
OK will cause a sfc and 850mb low to develop across central and
eastern OK. Some of the numerical models develop weak isentropic
lift across southeast KS and western MO. The extreme southeast
counties may see a few isolated showers but at this time I will keep
14 pops across the southeast counties of the CWA. Once again some
patchy fog may develop across north central KS by
sunrise...especially if skies remain clear through the night.
Overnight lows will drop to around 60 degrees across the western
counties of the CWA with lower to mid 60s across east central KS.
.LONG TERM...(Sunday THROUGH Friday)
ISSUED AT 231 AM CDT SAT AUG 29 2015
Remnants of upper trough moving through the area tonight will
weaken and leave a vort max in the vicinity of southern MO that
remains nearly stationary through Monday. This feature will
result in scattered clouds and a few showers that could extend
into extreme east central and southeast KS during this time. While
isolated showers aren`t out of the question in our far
southeastern forecast area south of I35, chances are low enough
that I did not include in any products at this time.
Other than the influence of the aforementioned vort max, an upper
ridge axis will extend from the southern Rockies into the Upper
Midwest early next week. From Tuesday through Wednesday, a
shortwave trough will move from the central Rockies to the Upper
Midwest, flattening the ridge axis and producing lift out ahead of
it. Main dynamics and lift with this system will be focused to
our north, but medium range models continue to have continuity in
producing QPF down into northeast KS with the best chance Tuesday
night.
After that, upper ridge builds back in which should keep the
eastern third of KS dry through the rest of the work week.
Pattern is favorable for temperatures to average several degrees
above normal for late August with highs near 90 for most of the
week and lows in the 65 to 70 degree range.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Sunday AFTERNOON)
ISSUED AT 1235 PM CDT SAT AUG 29 2015
Persistent MVFR cigs will remain pivoted around a 850 mb front
this afternoon, while dry air coming from the northeast attempts
to scatter cloud deck by 00Z tonight. Best chances for this
occurring is over KMHK. Otherwise expect the MVFR stratus to
remain in place overnight with some guidance indicating fog
developing underneath the frontal inversion. This unusual scenario
for this time of year leads to uncertainty in how low visibilitieswill
be based on what occurs with the stratus this afternoon. For now,
have introduced IFR 10Z to 15Z for low stratus and fog at all
sites. May need to monitor trends to adjust timing, but believe
the MVFR stratus will linger through at least 18Z Sunday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Bowen
SHORT TERM...Gargan
LONG TERM...GDP
AVIATION...Bowen
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
355 PM EDT SAT AUG 29 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 355 PM EDT SAT AUG 29 2015
19Z SFC ANALYSIS SHOWS HIGH PRESSURE EXITING TO THE EAST WHILE A
BROAD AREA OF LOW PRESSURE IS DRIFTING TOWARD THE STATE FROM THE
CENTRAL PLAINS. THE INCREASE IN MOISTURE AND LACK OF A CAP HAVE
ALLOWED A FEW CELLS TO DEVELOP THROUGH WESTERN AND NORTHERN PARTS
OF THE AREA THIS AFTERNOON. SO FAR...THE COVERAGE HAS BEEN FAIRLY
SPARSE AND THAT SHOULD BE THE CASE INTO THE EVENING AS THE
DIURNALLY DRIVEN INSTABILITY WANES. TEMPERATURES ARE IN THE MID
80S AT MOST PLACES WITH DEWPOINTS IN THE MID 60S. UNDER PARTLY
SUNNY SKIES WINDS ARE FROM THE SOUTH TO SOUTHWEST AT AROUND 10
KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A BROAD AND RATHER WEAK
TROUGH OVER THE OHIO AND TENNESSEE VALLEYS WITH SLOW MOVING
BATCHES OF ENERGY CAUGHT OVER THE REGION...STUCK BETWEEN
MARGINALLY HIGHER HEIGHTS TO THE WEST AND SOUTHEAST. GIVEN THE
BROAD AGREEMENT WITH THE MODELS HAVE FAVORED THE HIGHER RESOLUTION
GUIDANCE FROM THE HRRR AND NAM12 FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE THE ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS DIMINISHING TOWARD AND AFTER SUNSET WITH PARTLY
CLOUDY SKIES ANTICIPATED THROUGH THE NIGHT. PATCHY VALLEY FOG WILL
AGAIN FORM TOWARDS DAWN WITH A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT LIKELY SETTING UP. SUNDAY WILL SEE A BETTER CHANCE FOR
CONVECTION THROUGHOUT THE CWA WITH MORE CLOUDS HELPING TO KEEP
TEMPERATURES ABOUT A CATEGORY COOLER...BUT WITH CONDITIONS EQUAL
OR EVEN MORE HUMID THAN TODAY. AGAIN PATCHY FOG AND A MINOR RIDGE
TO VALLEY TEMP SPLIT CAN BE EXPECTED LATER SUNDAY NIGHT INTO
MONDAY MORNING.
STARTED WITH THE SHORTBLEND FOR TEMPERATURES...DEWPOINTS...AND
WINDS THROUGH THE EVENING BEFORE GOING WITH THE SUPERBLEND FOR
THE REST OF THE PERIOD. DID ADJUST THE MIN TEMPERATURES EACH NIGHT
FOR TERRAIN DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE
DRIER MAV NUMBERS THROUGHOUT THE SHORT TERM PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 330 PM EDT SAT AUG 29 2015
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ACROSS MUCH OF THE EASTERN
CONUS THROUGHOUT THE EXTENDED. MEANWHILE...BOTH THE REMNANTS OF TS
ERIKA AND A WEAK UPPER LEVEL LOW OVER THE MISSISSIPPI RIVER VALLEY
WILL BE THE FEATURES THAT WILL PREVENT US FROM HAVING A COMPLETELY
DRY AND CLEAR WEEK AHEAD. THE UPPER LEVEL RIDGE WILL BE THE MAIN
PLAYER...KEEPING STABLE AIR ACROSS THE REGION DURING THE OVERNIGHT
HOURS AS THE TEMPERATURES COOL. HOWEVER...DURING THE
DAY...INCREASING TEMPERATURES AND THE ABOVE MENTIONED UPPER LEVEL
TRIGGERS WILL RESULT IN SOME ISL TO SCT SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. OUR BEST CHANCES FOR SEEING PRECIP WILL BE DURING
THE DAY MONDAY AS THE LOW THAT WAS TS ERIKA MOVES FAR ENOUGH WEST TO
IMPACT FAR SE KY. IT WILL QUICKLY TRANSITION TO THE NE
HOWEVER...WITH AN APPROACHING SHORTWAVE AND THE DIMINISHING UPPER
LEVEL LOW OVER THE MISSISSIPPI VALLEY SHIFTING EASTWARD ACROSS KY
BY MID WEEK.
MOST OF THE WINDS THROUGH THIS PERIOD WILL BE FROM THE EAST AT THE
SURFACE...AND FROM THE WSW IN THE MID AND UPPER LEVELS. IN OTHER
WORDS...IT IS NOT VERY FAVORABLE FOR SUSTAINABLE THUNDERSTORM
DEVELOPMENT. NOT GOING TO RULE OUT SOME RUMBLES OF THUNDER...SO DID
KEEP MENTION OF TSRA IN FORECAST...BUT DON/T EXPECT STORMS TO BECOME
VERY TALL OR BE FAST MOVERS. NOT TO MENTION LATEST GFS FORECAST
SOUNDINGS DON/T SHOW LI/S BELOW -5C AND CAPE ABOVE 1500 J/KG /WITH
THE EXCEPTION OF MONDAY/...SO NOTHING TOO CONCERNABLE EXPECTED
THROUGH THE WEEK AT THIS POINT.
THE OVERALL RIDGE PATTERN AND LACK OF WIDESPREAD CLOUD COVER WILL
ALLOW TEMPERATURES TO SLOWLY INCREASE EACH DAY THROUGHOUT THE WEEK.
WHILE HIGH TEMPERATURES ON MONDAY WILL STILL BE CONTAINED IN THE LOW
TO MID 80S...WE COULD SEE UPPER 80S BY TUESDAY...AND POSSIBLY EVEN A
90 DEGREE SPOT OR TWO TO ROUND OUT THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 230 PM EDT SAT AUG 29 2015
ISOLATED CONVECTION WILL BE AROUND THROUGH THE FIRST PART OF THE
EVENING...BUT THE TAF SITES SHOULD BE SPARED. THE NIGHT WILL BE
QUIET WITH JUST SOME LIGHT FOG ANTICIPATED IN THE VALLEYS...
POSSIBLY AFFECTING THE SME AND LOZ TAF SITES. EXPECT MORE CLOUDS A
BIT LOWER DURING THE DAY SUNDAY WITH SCATTERED STORMS ANTICIPATED
FOR THE AFTERNOON. WINDS WILL BE FROM THE SOUTH TO SOUTHWEST
THROUGH THE REST OF THE DAY AND AGAIN ON SUNDAY GENERALLY AT 5 TO
10 KTS WITH SOME HIGHER GUSTS POSSIBLE AT SYM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
106 PM EDT SAT AUG 29 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (NOW THROUGH SUNDAY)...
ISSUED AT 235 AM EDT SAT AUG 29 2015
EARLY MORNING WATER VAPOR IMAGERY COMBINED WITH 500 MB HEIGHTS
SHOWED A MID LEVEL TROUGH EXTENDING FROM THE CENTRAL PLAINS
NORTHEASTWARD TOWARD EASTERN WISCONSIN...WHILE A BROAD CLOSED LOW
WAS ADVANCING NORTHWARD FROM THE GULF INTO THE DEEP SOUTH. THE LOWER
OHIO VALLEY LIED IN BETWEEN...AS OBSERVED BY IR SATELLITE IMAGERY
WHICH SHOWED MOSTLY CLEAR SKIES AND LIGHT WINDS. DEEPER
MOISTURE...CLOUDY SKIES...AND LIGHT RADAR RETURNS WERE OFF TO THE
NORTHWEST.
THE MAIN FORECAST CONCERN FOR TODAY IS PRECIPITATION CHANCES AS THE
TWO AFOREMENTIONED SYSTEMS TRACK TOWARD EACH OTHER. THE SOUTHERN
SYSTEM WILL DRAW MORE MOISTURE INTO THE AREA...CHARACTERIZED BY
DEWPOINTS APPROACHING THE UPPER 60S TO NEAR 70 THIS AFTERNOON. THE
NORTHERN SYSTEM WILL BEGIN TO WASH OUT AS IT SLOWLY ADVANCES
EASTWARD. OVERALL...DYNAMICS ARE RATHER WEAK WITH THESE SYSTEMS BUT
A WEAKLY OR UNCAPPED ENVIRONMENT ALONG WITH PEAK HEATING GENERATING
POCKETS OF INSTABILITY SHOULD BREAK OUT ISOLATED TO SCATTERED NON
SEVERE SHOWERS AND STORMS.
NEAR TERM HI-RES MODELS SHOW HIGH AGREEMENT SPATIALLY...TEMPORALLY
AND RUN TO RUN WHICH LEADS TO A HIGHER CONFIDENCE FORECAST FOR
TODAY. THE HRRR HAS BEEN VERY CONSISTENT SHOWING ISOLATED
SHOWERS/STORMS BREAKING OUT DURING THE EARLY AFTERNOON HOURS AS
CONVECTIVE TEMPS ARE REACHED. THE NSSL AND SPC WRF SOLUTIONS OFFER
SIMILAR SOLUTIONS AS WELL. THE HIGHEST COVERAGE LOOKS TO BE ALONG A
BOWLING GREEN TO FRANKFORT LINE AND WESTWARD...ALONG THE AXIS OF
GREATER INSTABILITY AND MOISTURE.
MOSTLY SUNNY SKIES THIS MORNING WILL BE REPLACED BY SCATTERED
CUMULUS AS WELL AS MID/HIGH CLOUDS...WHICH SHOULD MAKE FOR A PARTLY
TO MOSTLY CLOUDY AFTERNOON AT TIMES. PLAN ON HIGHS TO TOP OUT IN THE
MID TO BROKEN HIGH CLOUDS WILL OVERSPREAD TAF SITES THIS MORNING...AND LOOK
FOR SOUTHERLY WINDS TO DEVELOP. WITH A WEAKLY UNSTABLE AIR MASS AND
A COUPLE WEATHER SYSTEMS NEARBY...THERE WILL BE A SLIGHT CHANCE OF A
SHOWER/STORM FROM EARLY AFTERNOON THROUGH THE END OF THE TAF PERIOD.
HOWEVER COVERAGE IS NOT EXPECTED TO BE VERY HIGH SO WILL CONTINUE TO
LEAVE OUT OF TAF. MOSTLY CLOUDY SKIES SHOULD LMIITUPPER 80S. THE
INCREASE IN DEWPOINTS WILL MAKE IT FEEL SLIGHTLY MORE MUGGY THAN
RECENT DAYS.
EXPECTING A DROP OFF IN PRECIPITATION THIS EVENING WITH THE LOSS OF
HEATING...THOUGH WILL STILL CARRY A CHANCE THROUGH THE OVERNIGHT
WITH THE WEAK TROUGH OVERHEAD. SUNDAY STILL LOOKS TO BE THE BETTER
DAY FOR PRECIPITATION AS WE`LL HAVE A MORE FAVORABLE ENVIRONMENT AND
OVERALL DYNAMICS. PRECIPITATION COVERAGE STILL LOOKS TO BE
SCATTERED...SO KEPT CHANCES IN THE 30-40 PERCENT RANGE.
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
ISSUED AT 300 AM EDT SAT AUG 29 2015
MONDAY - WEDNESDAY...
A WEAK UPPER LOW NEAR THE OHIO VALLEY MAY PROVIDE ENOUGH SUPPORT FOR
ISLD SHOWERS/STORMS MAINLY ALONG AND EAST OF I-65 SUNDAY NIGHT AND
MONDAY. THE GFS IS MOST OPTIMISTIC WITH THIS CONVECTION AND EVEN
THIS NOTORIOUSLY WET MODEL ISN`T SHOWING MUCH PRECIP.
TUESDAY LOOKS TO BE DRY WITH THE NEXT CHANCE FOR SHOWERS/STORMS
ARRIVING FOR WED. MID RANGE MODELS ARE DIFFERENT IN DEPICTING THE
MAIN SOURCE FOR FORCING/MOISTURE. THE GFS INDICATES THE REMNANTS OF
T.S. ERIKA WILL BE THE CAUSE WHILE THE ECMWF SUGGESTS A NORTHERN
STREAM TROUGH WILL BE THE CAUSE. EITHER WAY WILL CARRY 20-30% POPS
FOR WED.
TEMPS FOR EARLY TO MID WEEK WILL BE ON THE INCREASE BACK TO SEASONAL
NORMS WITH HIGHS RANGING MAINLY THE MID TO UPPER 80S WITH A FEW
LOCATIONS NEAR 90 TUES/WED.
THURSDAY - FRIDAY...
LONG RANGE MODELS AGREE THAT A STRONG UPPER RIDGE AXIS WILL BUILD
INTO PORTIONS OF THE PLAINS/MIDWEST. THICKNESSES WILL INCREASE OVER
THE OHIO VALLEY AS A RESULT BRINGING TEMPS SLIGHTLY ABOVE NORMAL FOR
THE LATTER HALF OF THE WEEK (UPPER 80S/LOWER 90S FOR HIGHS).
ALTHOUGH A CLEAR TRIGGER IS NOT APPARENT, SOME LONG RANGE SIGNALS
SUGGEST A DIRTY RIDGE WITH SUBTLE WAVES MAY CAUSE MAINLY DIURNAL
CONVECTION PEAKING DURING THE AFTERNOON/EVENING HOURS BOTH
THURS/FRI. THUS WILL HAVE LOW POPS BOTH OF THESE DAYS.
&&
.AVIATION (18Z TAF UPDATE)...
ISSUED AT 105 PM EDT SAT AUG 29 2015
ISOLATED TO WIDELY SCATTERED SHOWERS HAVE DEVELOPED IN AN UNSTABLE
AIRMASS THIS AFTERNOON. EXPECT COVERAGE TO INCREASE SLIGHTLY ALONG
WITH A FEW T-STORMS AS WE GO THROUGH THE AFTERNOON/EARLY EVENING
HOURS. ANY STORM WILL BE CAPABLE FOR GUSTY WINDS AND BRIEF HEAVY
RAINFALL. WITH COVERAGE ONLY EXPECTED TO BE 30% DURING PEAK HEATING,
WILL CONTINUE TO ONLY MENTION VCTS, AND AMEND IF A T-STORM OR SHOWER
LOOKS TO IMPACT VISIBILITIES AT A TERMINAL. EXPECT COVERAGE TO
DIMINISH AROUND 6-7 PM EDT WITH THE LOSS OF HEATING AND WITH DRIER
AIR EVIDENT ON WATER VAPOR IMAGERY MOVING IN FROM THE SW. LEX MAY
HOLD ON AN HOUR OR TWO LONGER BEING FURTHER EAST.
OTHERWISE, EXPECT VFR WITH SCT-BKN SKY COVER IN THE 3-4 K FT RANGE
THIS AFTERNOON AND A STEADY SSW WIND. SHOULD BE RELAIVELY QUIET
OVERNIGHT WITH LIGHT AND VARIABLE WINDS. PERHAPS SOME BRIEF MVFR VIS
AT BWG IN THE MORE MOIST AIRMASS, BUT MID AND UPPER CLOUDS COULD BE
A LIMITING FACTOR. EXPECTING A REPEAT OF CONDITIONS ON SUNDAY
SIMILAR TO TODAY.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........ZBT
LONG TERM.........AMS
AVIATION..........BJS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1037 AM PDT SAT AUG 29 2015
.SYNOPSIS...MOSTLY DRY AND BREEZY CONDITIONS ARE EXPECTED INTO EARLY
NEXT WEEK WITH ANY THUNDERSTORM ACTIVITY CONFINED TO EASTERN MOHAVE
COUNTY SATURDAY AND SUNDAY AFTERNOON. TEMPERATURES WILL REMAIN
SEVERAL DEGREES ABOVE NORMAL SATURDAY THEN BECOME MORE SEASONAL
SUNDAY AND MONDAY. DRY CONDITIONS ALONG WITH BREEZY AND COOLER
CONDITIONS ARE EXPECTED THROUGH THE UPCOMING LABOR DAY WEEKEND.
&&
.UPDATE...THE 12Z LAS VEGAS SOUNDING REVEALED LIMITED MOISTURE STILL
LINGERING OVER SOUTHERN NEVADA WITH ABOUT 1 INCH OF PWAT. A FAIRLY
STRONG INVERSION IN THE 600-550 LAYER SHOULD PROVIDE A GOOD CAP FOR
CONVECTION. ALSO...SLIGHTLY DRIER AIR WILL WORK WITH THE INCREASING
SOUTHWEST FLOW ALOFT. THE LATEST HRRR MODEL INDICATES CONVECTION
DEVELOPING SOUTH OF LAS VEGAS OVER THE MCCULLOUGH RANGE BY EARLY
AFTERNOON. THE AFOREMENTIONED FACTORS SHOULD WORK AGAINST THAT...BUT
IT IS STILL POSSIBLE THAT THE CAP MAY NOT HOLD OVER THE MOUNTAINS
SOUTH OF LAS VEGAS. THE GRIDS WERE UPDATED TO ADD ISOLATED
THUNDERSTORMS OVER SOUTHERN CLARK COUNTY AND ALSO FOR EASTERN
LINCOLN COUNTY.
&&
.AVIATION...FOR MCCARRAN...SOUTHEASTERLY WINDS ARE EXPECTED TO
TRANSITION TO GUSTY SOUTHWEST WINDS BETWEEN 19-20Z. TEMPERATURES
WILL CLIMB TO NEAR 107 DEGREES. THERE IS A SMALL CHANCE OF TS OVER
THE MOUNTAINS TO THE SOUTHEAST OF LAS VEGAS WHICH COULD PRODUCE
GUSTY/ERRATIC OUTFLOW WINDS AT THE TERMINAL. HAVE ADDED A TEMPO
GROUP WITH GUSTY SOUTHEAST WINDS TO ACCOUNT FOR THIS POSSIBILITY.
CHANCES FOR TS WILL DIMINISH AFTER 00Z. SOUTHWEST WINDS WILL
CONTINUE OVERNIGHT...SLIGHTLY STRONGER THAN NORMAL. GUSTY SOUTHWEST
WINDS ARE EXPECTED AGAIN SUNDAY WITH TEMPERATURES DOWN 3-5 DEGREES.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GUSTY SOUTH TO SOUTHWEST WINDS ARE EXPECTED ACROSS THE
REGION TODAY WITH SPEEDS GENERALLY 10-15KTS WITH GUSTS 20-25 KTS
EAST OF A LINE FROM KELY TO KNXP AND 5-10KTS STRONGER TO THE WEST OF
THIS LINE. STRONG WINDS ACROSS THE SIERRA COULD CREATE AREAS IF
MECHANICAL TURBULENCE TO THE EAST OF THE CREST. THUNDERSTORMS WILL
BE POSSIBLE ACROSS THE HIGHER TERRAIN OF MOHAVE COUNTY...WITH LESSER
CHANCES OVER THE HIGH TERRAIN OF EASTERN LINCOLN...CLARK AND SAN
BERNARDINO COUNTIES. TS TODAY HAVE THE POTENTIAL TO PRODUCE VERY
STRONG/ERRATIC WINDS. CHANCES FOR TS WILL DIMINISH RAPIDLY THIS
EVENING. GUSTY SOUTH TO SOUTHWEST WINDS ARE EXPECTED AGAIN SUNDAY. &&
.PREV DISCUSSION...
140 AM PDT SAT AUG 29 2015
.SHORT TERM...THROUGH MONDAY NIGHT...
TROUGH PUSHING INTO THE WEST COAST WILL BRING DRIER AND MORE STABLE
CONDITIONS TO MUCH OF THE FORECAST AREA TODAY. FORECASTED SOUNDINGS
STILL SHOWING SOME MOISTURE REMAINING IN THE MID LEVELS SO WE SHOULD
STILL SEE A FEW CUMULUS CLOUDS THIS AFTERNOON...BUT THE SOUNDINGS
ARE ALSO SHOWING A WARMING LAYER JUST ABOVE THIS MOISTURE SO
ANYTHING THAT DOES DEVELOP SHOULD REMAIN CAPPED AND THUNDERSTORMS
ARE NOT EXPECTED OUTSIDE OF EASTERN MOHAVE COUNTY WHERE SOME SLIGHT
INSTABILITY REMAINS. WITH THE APPROACH OF THE TROUGH THE SOUTHWEST
FLOW WILL INCREASE THIS AFTERNOON BRINGING BREEZY CONDITIONS TO MUCH
OF THE AREA WITH WINDY CONDITIONS OVER PORTIONS OF ESMERALDA AND
CENTRAL NYE COUNTIES. WINDS ARE EXPECTED TO REMAIN BELOW ANY
ADVISORY LEVELS. TEMPERATURES TODAY ARE EXPECTED TO TOP OUT AS THE
WARMEST OF THE WEEK WITH READINGS GENERALLY ABOUT 6-8 DEGREES ABOVE
NORMAL. EXCESSIVE HEAT CRITERIA IS CURRENTLY AT 108 DEGREES AND FEEL
THAT LAS VEGAS WILL FLIRT WITH THAT NUMBER...ESPECIALLY WITH THE
GOOD MIXING EXPECTED. HOWEVER...SINCE ITS BORDERLINE ELECTED NOT TO
ISSUE ANY EXCESSIVE HEAT PRODUCTS.
SLIGHT COOLING WILL TAKE PLACE SUNDAY AS THE TROUGH MOVES CLOSER TO
THE REGION AND HEIGHTS LOWER. WINDS WILL STILL REMAIN GUSTY OVER THE
EASTERN HALF OF THE AREA WITH BREEZY CONDITIONS EXPECTED. WINDS WILL
BE A BIT LIGHTER ACROSS THE WESTERN HALF OF THE AREA. WE WILL
PROBABLY SEE A FEW CLOUDS OVER EASTERN MOHAVE COUNTY...BUT
THUNDERSTORMS SHOULD REMAIN EAST OF THE AREA. BY MONDAY THERE SHOULD
BE ENOUGH DRY AIR WITH THE SOUTHWEST FLOW THAT ANY LOW LEVEL
MOISTURE WILL BE PUSHED EAST OF THE AREA. TEMPERATURES WILL ALSO
COOL A FEW MORE DEGREES MONDAY AND TOP OUT VERY CLOSE TO NORMAL FOR
THIS TIME OF YEAR.
.LONG TERM...TUESDAY THROUGH SATURDAY.
HAS THE 2015 MONSOON SEASON COME TO AN END? AT LEAST THROUGH THE
UPCOMING LABOR DAY HOLIDAY WEEKEND IT LOOKS SO. MONSOON MOISTURE
WILL BE SUPPRESSED WELL TO OUR SOUTHEAST THANKS TO A BROAD TROUGH
ENCOMPASSING THE GULF OF ALASKA, PAC NW AND WRN CANADA TUESDAY. THE
TROUGH IS FORECAST TO AMPLIFY OVER THE WESTERN STATES BY WEEKS END
AS ENERGY DIGS THROUGH THE NORTHERN GREAT BASIN. REGION WILL REMAIN
DRY THROUGH THE PERIOD WITH BREEZY TO LOCALLY WINDY
AFTERNOON/EVENING HOURS. THE ENTIRE PERIOD LOOKS TO HAVE HIGH
TEMPERATURES BETWEEN 3 TO 5 DEGREES BELOW NORMAL. THE DRIER AIR WILL
ALSO ALLOW FOR MORE COMFORTABLE OVERNIGHT LOWS AS WELL.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION WILL NOT BE
NECESSARY. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES. &&
$$
UPDATE.....ADAIR
AVIATION...WOLCOTT
PREV DISCUSSION...GORELOW/PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
!--NOT SENT--!
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1157 AM MDT SAT AUG 29 2015
.AVIATION...
18Z TAF CYCLE
WDLY SCT-SCT THUNDERSTORM ACTIVITY IS EXPECTED OVER AND NEAR MOST
MOUNTAIN RANGES AND OVER THE SE PLAINS WITH ISOLD ACTIVITY
ELSEWHERE. SHOWERS AND THUNDERSTORMS WILL GRADUALLY DIMINISH/DISSIPATE
AFTER SUNSET WITH THE EXCEPTION OF FAR WEST-CENTRAL NM WHERE ISOLD
ACTIVITY IS POSSIBLE UNTIL APPROX 07Z. EXPECT BRIEF MVFR CIGS WITH
STRONGER STORMS. AREAS OF DENSE FOG IS LIKELY ONCE AGAIN IN THE
MORENO VALLEY AND KAXX SUNDAY MORNING.
33
&&
.PREV DISCUSSION...341 AM MDT SAT AUG 29 2015...
.SYNOPSIS...
STORM COVERAGE WILL LOWER SLIGHTLY TODAY ALTHOUGH LOCALLY HEAVY
RAIN WILL REMAIN POSSIBLE OVER THE MOUNTAINS...ESPECIALLY
SOUTHWEST AND NORTHERN SACRAMENTOS. THE FAVORED STORM COVERAGE
AREAS WILL SHIFT WESTWARD AND FAVOR THE CONTINENTAL DIVIDE TO THE
ARIZONA BORDER ON SUNDAY. A PACIFIC TROUGH WILL NUDGE CLOSER TO
THE STATE ON MONDAY AND SHIFT THE MAIN STORM COVERAGE FURTHER
EAST. LOCALLY HEAVY RAIN WILL REMAIN POSSIBLE SUNDAY/MONDAY. THE
MONSOON MOISTURE PLUME...ALBEIT DISJOINTED AT TIMES... WILL REMAIN
OVER PORTIONS OF THE STATE THROUGH THE REST OF THE WEEK. A MORE
CONCENTRATED MOISTURE PLUME WILL BE POSSIBLE NEXT WEEKEND AS A
PACIFIC TROUGH STRENGTHENS AND DEEPENS TO THE WEST OF THE STATE.
&&
.DISCUSSION...
MASSAGED POPS/SKY COVER AND WEATHER HERE AND THERE BUT NO MAJOR
CHANGES. THE OVERALL WEATHER THEME APPEARS TO BE SIMILAR. A LITTLE
LESS STORM COVERAGE WITH THE FOCUS GRADUALLY SHIFTING WESTWARD
TODAY. THE MAIN FOCUS ON SUNDAY STILL APPEARS TO BE ACROSS THE
WESTERN THIRD AND CURRENT POPS REFLECT THAT. THE PACIFIC TROUGH
WILL NUDGE CLOSER TO THE STATE ON MONDAY THUS SHIFTING THE MAIN
MOISTURE PLUME A LITTLE FURTHER EAST. IT APPEARS THAT THE PAC
TROUGH WOULD REFORM OR DEEPEN TO THE WEST TUESDAY AND CONTINUE
INTO NEXT WEEKEND. THIS WOULD PLACE THE MAIN MONSOONAL MOISTURE
PLUME OVER SOME PORTION OF THE STATE DURING THIS PERIOD. THUS AN
ACTIVE PERIOD BUT NOTHING OUT OF THE ORDINARY AT THIS TIME. WILL
BE FOLLOWING THE UPPER HIGH PROGRESSION BECAUSE ONCE IT
CONSOLIDATES/LESS HIGH CENTERS/ AND MOVES EAST OF THE STATE THEN A
JUICIER MOISTURE FLOW SHOULD ENSUE. THAT APPEARS POSSIBLE LATE
WEEKEND OR DURING NEXT WEEKEND.
SOME MODEL DISPCREPANCIES FOR TODAYS POP FORECAST. HRRR IS MUCH
MORE BULLISH ACROSS THE EASTERN PLAINS COMPARED TO THE NAM/GFS.
LATEST WATER VAPOR IMAGERY SHOWS A DRIER AND MORE STABLE AIRMASS
POISED TO THE NORTH OF THE STATE SO WOULD EXPECT SOME OF THIS AIR
TO MAKE IT INTO EASTERN NM AS THE DAY PROGRESSES. DESPITE THIS
IMPACT...DECIDED TO BEEF UP POPS A BIT MORE ACROSS THE EC/SE
PLAINS THANKS TO THE LATEST HRRR FORECAST. EITHER WAY...MAIN FOCUS
WILL BE SHIFTING SLIGHTLY MORE TO THE WEST. STEERING FLOW FOR THE
STORMS APPEARS TO BE PRETTY LIGHT DUE TO THE CLOSE PROXIMITY TO
THE HIGH CENTER. ONE NOTABLE STEERING FLOW DIRECTION WOULD BE THE
NE FLOW ORIGINATING FROM THE SANDIA MTNS. THIS FLOW USUALLY BODES
WELL FOR PORTIONS OF THE ABQ NE HEIGHTS SO FOOTHILL RECREATIONALISTS
SHOULD BE COGNIZANT OF THAT POTENTIAL IMPACT. ALSO BEEFED UP QPF
AND POPS ACROSS THE GILA REGION AND NORTHERN SACRAMENTO MTNS.
SINCE THE CELLS SHOULD TRAVEL SOUTHWARD OVER THE SACS...RESIDENCE
TIME MAY NOT BE ALL THAT MUCH...BUT SOMETHING TO WATCH IN TERMS
OF LOCALIZED FLOODING. LOCALIZED FLOODING ALSO POSSIBLE ACROSS
THE GILA REGION. BASED ON THE LATEST NASASPORT SOIL MOISTURE
IMAGERY...CATRON COUNTY APPEARS TO BE RATHER MOIST AS WELL AS
PORTIONS OF THE CENTRAL MTNS/EAST SLOPES.
NOT A LOT OF SIGNIFICANT CHANGES IN THE LATEST MODELING. THE
INITIAL PAC TROUGH IS EXPECTED TO SHEAR OUT ACROSS THE
NORTHERN/CENTRAL ROCKIES/NORTHERN PLAINS SUNDAY/MONDAY. LOCALLY
HEAVY RAIN AND A DIFFUSE MONSOONAL MOISTURE PLUME WILL FAVOR THE
CONTINENTAL DIVIDE WESTWARD SUNDAY. THEN SHIFT A BIT MORE TO THE
EAST ON MONDAY BASED ON THE INITIAL PAC TROUGH EJECTION.
THE PAC TROUGH WILL DEEPEN TO THE WEST OF THE STATE TUESDAY
THROUGH THE END OF THE WEEK. PRETTY TYPICAL PATTERN FOR
SEPTEMBER...AT LEAST BASED ON THE PAST FEW YEARS. MONSOONAL
MOISTURE WILL TRY TO MOVE NORTHWARD AHEAD OF THE TROUGH AND
CONTINUE SH/TS OVER THE FORECAST AREA. SUBTLE DAY TO DAY CHANGES
WILL DEPEND ON WEAK VORTICE WAVES ORIGINATING FROM MEXICO AS WELL
AS A DRIER AND MORE STABLE AIRMASS ROTATING AROUND THE HIGH
CENTER. IT APPEARS THAT BASED ON THE PAC TROUGH PROGRESSION...THE
UPPER HIGH WOULD EVENTUALLY SHIFT EAST OF THE STATE ALTHOUGH THIS
PROGRESSION WILL MOST LIKELY JUMP AROUND A BIT BECAUSE THE MODELS
HAVE BEEN HAVING A HARDER TIME WITH THE PROGRESSION OF THE PAC
TROUGH ALONG THE WEST COAST. EITHER WAY...WOULD EXPECT THE
MONSOONAL MOISTURE PLUME...ORIGINATING FROM MEXICO...TO BECOME
MORE CONSOLIDATED AROUND THE UPPER HIGH OR BECOMING LESS DIFFUSE.
WILL JUST HAVE TO WAIT ON SEE ON THAT ONE. DECIDED TO INCREASE
TEMPS SLIGHTLY ABOVE MODEL GUIDANCE OR SUPER BLEND LEVELS DURING
THE EXTENDED PERIOD. ALSO LOWERED MIN TEMPS IN THE HIGHER MTN
BASINS SUCH AS THE MORENO VALLEY DUE TO LOWERING DEWPOINTS.
50
&&
.FIRE WEATHER...
BACK DOOR FRONT HAS PUSHED WESTWARD TO THE CONTDVD EARLY THIS
MORNING. THIS WILL SET THE STAGE FOR MORE ACTIVITY ACROSS WESTERN NM
TODAY AS COMPARED TO YESTERDAY...THOUGH WETTING RAINS WILL STILL BE
SPOTTY...WITH THE WEST CENTRAL HIGHLANDS BEING THE EXCEPTION. HI-RES
MODELS STILL SHOWING A FAIR AMOUNT OF ACTIVITY ACROSS THE EASTERN
PLAINS AS WELL...BUT WITH DRIER AIR MOVING IN...IT SHOULD NOT BE AS
WIDESPREAD OR AS ORGANIZED AS YESTERDAY. STORM MOTION LOOKS TO SHIFT
A BIT TODAY...PERHAPS MORE TOWARD THE SOUTHWEST OR WEST ACROSS THE
EAST AND MORE TOWARD THE NORTH ACROSS THE WEST.
THE UPPER HIGH IS STILL ON TRACK TO ELONGATE FROM SW TO NE FROM SE
AZ TO NE NM ON SUNDAY. MEANWHILE...THE CENTROID OF THE MID LEVEL
HIGH WILL SHIFT OVER EASTERN NM OR WEST TEXAS. THIS WILL ALLOW MID
LEVEL MOISTURE TO STREAM NORTHWARD ACROSS FAR WESTERN NM AND EASTERN
AZ. APPEARS THAT THE BEST PRECIP CHANCES WILL BE ACROSS THE WESTERN
THIRD OF THE STATE AND SOME SPOTTY HEAVY RAINFALL WILL BE POSSIBLE.
STORM MOTION WILL GENERALLY BE TOWARD THE NORTHEAST AROUND 5-10 MPH.
THE MOISTURE PLUME STILL LOOKS TO SHIFT EASTWARD ON MONDAY...
FOCUSING THE BEST CHANCE FOR TSTMS FROM THE WEST CENTRAL HIGHLANDS
NEWD TO THE NE PLAINS. STORM MOTION WILL LIKELY BE A BIT MORE
ERRATIC...BUT GENERALLY FROM WEST TO EAST OR SW TO NE.
APPEARS THAT THE MOISTURE PLUME WILL STILL BE HOVERING OVER NM ON
TUESDAY...THOUGH NOT AS ROBUST AS SUNDAY OR MONDAY. WILL STILL LOOK
FOR STORMS...MAINLY OVER THE HIGH TERRAIN.
ECMWF AND CANADIAN MODELS CONTINUE TO SHOW THE UPPER HIGH CENTERED
FARTHER SOUTH WEDNESDAY...ALLOWING FOR DRIER WESTERLY FLOW ACROSS
NORTHERN NM. THE GFS HANGS ONTO A DISORGANIZED PLUME ON WEDNESDAY
WITH THE HIGH OVER WEST TEXAS...THOUGH BY THURSDAY...THE HIGH
WEAKENS ALLOWING THAT DRIER AIR INTO NORTHERN NM. WITH MODEL
INCONSISTENCIES OF LATE...HARD TO HAVE A DEFINITE ANSWER...BUT IT
DOES LOOK LIKE MODELS ARE TRENDING TOWARD A DRIER LATTER HALF OF
NEXT WEEK.
VERY LITTLE TEMPERATURE CHANGES OVER THE NEXT SEVERAL DAYS... WITH
HIGHS GENERALLY AT OR ABOVE NORMAL. HUMIDITIES WILL LOWER WED/THURS
MAINLY ACROSS NORTHERN NM IF THE AFOREMENTIONED PATTERN COMES TO
FRUITION. WEAK TRANSPORT WINDS WILL CONTINUE TO RESULT IN POOR TO
FAIR VENT RATES ACROSS NORTH CENTRAL NM TODAY...BUT SHOULD GENERALLY
IMPROVE INTO THE GOOD TO EXCELLENT RANGE NEXT WEEK. ONE EXCEPTION
MAY BE ACROSS THE SANGRE DE CRISTO MOUNTAINS ON MONDAY.
34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
11
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 PM EDT SAT AUG 29 2015
.SYNOPSIS...SURFACE HIGH PRESSURE REMAINS OVER MUCH OF THE REGION
FOR THE REST OF THE WEEKEND. AN UPPER LEVEL DISTURBANCE MOVES FROM
THE NORTHERN GULF OF MEXICO ACROSS THE WESTERN CAROLINAS SUNDAY
THROUGH EARLY MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 905 AM SATURDAY...
WHILE THE LATEST SURFACE ANALYSIS SHOWED HIGH PRESSURE OVER CENTRAL
NORTH CAROLINA...AND SPC MESOANALYSIS DATA SHOWED LOW PRECIPITABLE
WATER VALUES WITH AN 850MB RIDGE IN PLACE AND LIMITED 850MB MOISTURE
ADVECTION...MID- AND HIGH-LEVEL CLOUDS WERE SPREADING OVER CENTRAL
NORTH CAROLINA FROM THE SOUTH. THE LATEST WATER VAPOR IMAGES
INDICATED THE INCREASE OF THE MID-LEVEL MOISTURE WELL...STREAMING
NORTH AHEAD OF AN UPPER LOW OVER THE NORTHERN GULF. THE CANADIAN
CLOUD COVER MODEL...WHICH SEEMED TO HAVE A GOOD HANDLE ON THE CLOUD
COVER...SPREADS HIGH-LEVEL CLOUDS OVER CENTRAL NORTH CAROLINA FROM
THE SOUTHWEST DURING THE DAY...WITH NUMEROUS CLOUDS EXPECTED EVEN
OVER THE NORTHERN COASTAL PLAIN BY 18Z TO 20Z.
EARLY MORNING VISIBLE IMAGES SUGGESTS THE INITIAL SURGE OF HIGH
CLOUDS IS SOMEWHAT THIN...WHICH MAY PROVIDE FOR TIME FOR
TEMPERATURES TO RECOVER. AS SUN BECOMES MORE FILTERED OVER TIME WITH
LIKELY A GREATER DEGREE OF OPAQUE UPPER-LEVEL CLOUDS...THE EFFECT
SHOULD DAMPEN THE TEMPERATURE RISE. STILL...DID NOT LOWER MAXES TOO
MUCH...ONLY ABOUT A DEGREE OR SO...AS THERE MAY BE ENOUGH THIN SPOTS
TO GET WARMING SUFFICIENT FOR ABOUT 10 TO 15 DEGREES OF TEMPERATURE
INCREASE BEYOND THIS WRITING AT AN EARLY SUN TIME. RAP MODEL
SOUNDINGS SHOW MOISTENING ONLY ALOFT...WITH DRY AIR BELOW 500MB AND
A VERY CAPPED AIR MASS.
TONIGHT...MID-HIGH LEVEL CLOUDS WILL THICKEN IN RESPONSE TO THE
APPROACH OF THE NORTHERN GULF S/W THOUGH LIFT TO GENERATE ANY
SHOWERS APPEARS TO BE LACKING. WEAK (EMPHASIS ON WEAK) LOW LEVEL
ISENTROPIC LIFT MAY GENERATE A SHOWER OR SPRINKLES AROUND DAYBREAK
OVER THE FAR SOUTHERN PIEDMONT. THE INCREASING CLOUDINESS AND A
MODIFYING AIR MASS WILL YIELD MIN TEMPS A FEW DEGREES WARMER THAN
LOW TEMPS EXPECTED THIS MORNING. MIN TEMPS MID 60S NORTH TO THE
UPPER 60S SOUTH.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 333 AM SATURDAY...
HAVE TRENDED FORECAST THIS PERIOD A LITTLE WETTER...ESPECIALLY
SUNDAY NIGHT ACROSS THE PIEDMONT AND SANDHILLS.
ATMOSPHERE WILL CONTINUE TO MOISTEN AS NORTHERN GULF SYSTEM LIFTS
NEWD ACROSS GA AND INTO THE SOUTHERN APPALACHIANS LATE IN THE DAY.
THE APPROACH OF THIS SYSTEM WILL INDUCE A LOW LEVEL SELY
FLOW...RESULTING IN AN UPSLOPE COMPONENT TO THE LOW LEVEL FLOW OVER
THE SOUTHERN-WESTERN PIEDMONT. THE GFS SOLUTION IS A BIT MORE
AGGRESSIVE WITH THIS SCENARIO COMPARED TO THE NAM WHILE THE 00Z
ECMWF FAVORS THE GFS SOLUTION. INCREASING UPPER DIVERGENCE BY SUNDAY
AFTERNOON IN CONJUNCTION WITH A SLIGHTLY UNSTABLE AND INCREASINGLY
MOIST AIR MASS SHOULD SUPPORT THE DEVELOPMENT OF A FEW SHOWERS AND
AN ISOLATED STORM...MAINLY ACROSS PORTIONS OF THE SOUTHERN PIEDMONT
AND THE SANDHILLS. MAY SEE ADDITIONAL COVERAGE OVER THE
SANDHILLS/SOUTHERN COASTAL PLAIN DUE TO THE INLAND MOVING SEABREEZE.
THUS...WILL INCREASE POPS BIT FROM THE PREVIOUS FORECAST...UP TO 40
PERCENT OVER THE SOUTH AND WEST SECTIONS BY LATE IN THE DAY/SUNDAY
EVENING.
DUE TO EXPECTED EXTENSIVE CLOUDINESS...HAVE ADJUSTED MAX TEMPS DOWN
A BIT OVER THE WEST AND SW...WITH LITTLE CHANGE ELSEWHERE. IF CLOUDS
ARE LOWER/THICKER THAN EXPECTED OR SHOWER COVERAGE MORE EXTENSIVE BY
AFTERNOON...MAX TEMPS MAY END UP BEING 3-4 DEGREES COOLER THAN
FORECAST EVERYWHERE.
SUNDAY NIGHT...S/W LIFTS NEWD IMMEDIATELY WEST OF OUR REGION LATE IN
THE NIGHT...MAXIMIZING UPPER DIVERGENCE. IN THE 850-700MB LAYER WEAK
SPEED CONVERGENCE IN THE MOIST LAYER. THUS...SHOULD SEE A THREAT FOR
A FEW SHOWERS THROUGHOUT THE NIGHT...MAINLY ACROSS THE PIEDMONT. MIN
TEMPS MAINLY IN THE UPPER 60S TO NEAR 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 355 AM SATURDAY...
THE MODELS ARE IN BETTER AGREEMENT TODAY REGARDING THE
EJECTION/PROGRESSION OF A SHORTWAVE TROUGH --INITIALLY A CLOSED LOW
OVER THE CENTRAL GULF COAST THIS MORNING-- FROM THE CENTRAL
APPALACHIANS TO THE MIDDLE ATLANTIC COAST ON MON. MEANWHILE...AN
UPSTREAM KICKER SHORTWAVE TROUGH WILL AMPLIFY INTO THE SOUTHERN
PLAINS TO LOWER AND MID MS VALLEY AND RE-CARVE THE TROUGH
WESTWARD...AND CONSEQUENTLY ALLOW THE SUB-TROPICAL RIDGE TO BULGE
WESTWARD INTO THE SOUTHEAST US. A STRONGLY POSITIVELY-TILTED SHEAR
AXIS WILL SEPARATE THE SOUTHEASTERN RIDGE AND ANOTHER FORECAST TO
BUILD ACROSS THE OH VALLEY AND GREAT LAKES...AND THIS FEATURE WILL
INITIALLY DRAW TROPICAL MOISTURE ASSOCIATED WITH (AND IN ADVANCE OF)
ERIKA...NORTHWARD THROUGH THE CAROLINAS EARLY NEXT WEEK.
THEREAFTER...MOISTURE FROM (AND THE OVERALL INFLUENCE OF)
ERIKA...WILL BE DEPENDENT ON HOW ERIKA EVOLVES DURING THE NEXT
SEVERAL DAYS...WHICH IS A RELATIVELY LOW CONFIDENCE FORECAST.
THE ENVELOPE OF GUIDANCE SOLUTIONS HAS CONTINUED A WESTWARD TREND
WITH THE TRACK OF WHAT BECOMES OF ERIKA...WITH THE PREFERRED NHC
TRACK NOW THROUGH THE EASTERN GULF OF MEXICO/ALONG THE WEST COAST OF
FL EARLY NEXT WEEK...TO A POSITION NEAR THE FL PANHANDLE OR SOUTHERN
GA BY WED. CONSIDERABLE FORECAST UNCERTAINTY REMAINS WITH ERIKA...
HOWEVER...SINCE THE CIRCULATION MAY DISSIPATE ALTOGETHER DUE TO THE
INTERACTION WITH BOTH LAND AND A HOSTILE WIND SHEAR ENVIRONMENT
DURING THE NEXT 24-36 HOURS. OR IF IT SURVIVES... REGENERATION/
STRENGTHENING WILL BE POSSIBLE OVER THE WARM WATERS AND IN A
WEAKENING WIND SHEAR ENVIRONMENT OVER THE FL STRAITS AND EASTERN GOM.
REGARDLESS...IT STILL APPEARS THAT THE LOW LEVEL VORTICITY
CENTER...IN WHATEVER STATE IT MAY BE BY THE MIDDLE OF NEXT
WEEK...WILL LIKELY BE SUPPRESSED MOSTLY SOUTH AND/OR WEST OF CENTRAL
NC BY THE MERGING OF THE AFOREMENTIONED RIDGES ALOFT FROM THE GREAT
LAKES TO THE SE COAST. AS SUCH...OUR SENSIBLE WEATHER WILL LIKELY
INSTEAD BE INFLUENCED INDIRECTLY BY ASSOCIATED MOISTURE STREAMING
NNE ALONG THE AFOREMENTIONED SHEAR AXIS...WHICH WOULD RESULT IN BOTH
VARIABLY CLOUDY CONDITIONS AND SUPPORT FOR SLIGHTLY ABOVE CLIMO
PRECIPITATION CHANCES - HIGHEST SOUTH IN CLOSEST PROXIMITY TO THE
REMNANTS OF ERIKA. TEMPERATURES SHOULD BE CLOSE TO CLIMO - PERHAPS A
LITTLE BELOW /ABOVE FOR HIGHS/LOWS DEPENDING ON TIMING AND EXTENT OF
MOISTURE/CLOUD COVER.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 200 PM SATURDAY...
VFR CONDITIONS ARE EXPECTED THROUGH THE 18Z VALID TAF PERIOD.
SURFACE WINDS SUSTAINED UNDER 10KT SHOULD GRADUALLY VEER. SOUTHERLY
SURFACE WINDS SHOULD BE LIKELY BY MID-MORNING SUNDAY. THE GUIDANCE
CONSENSUS SUGGESTS A MORE VARIABLE SURFACE WIND TOWARD KFAY EARLY
SUNDAY MORNING...POSSIBLY EVEN A PERIOD OF A LIGHT NORTHWEST WIND...
BEFORE MIXING THERE RESULTS IN A SOUTHERLY WIND BY LATE SUNDAY
MORNING.
AN UPPER-LEVEL LOW OVER THE NORTHERN GULF OF MEXICO IS FORECAST BY
BOTH THE NAM AND GFS MODELS TO WEAKEN SOME WHILE LIFTING SLOWLY
NORTH...MOVING OVER THE WESTERN CAROLINAS LATE SUNDAY THROUGH EARLY
MONDAY. A DRY AIR MASS UNDER SURFACE HIGH PRESSURE AHEAD OF THE
UPPER LOW SHOULD KEEP ANY PRECIPITATION THAT OCCURS LIGHT WITH
CONDITIONS VFR. SHOULD MID- AND UPPER-LEVEL DRYING OCCUR LATE SUNDAY
NIGHT AS INDICATED BY THE NAM AND GFS MODEL SOUNDINGS...AREAS OF SUB-
VFR CONDITIONS IN LOW CLOUDS AND FOG WOULD OCCUR PRIOR TO DAWN
MONDAY IN MOIST LOW-LEVEL AIR. FROM MONDAY AFTERNOON INTO
THURSDAY...IN A MOIST AIR MASS AND MODEST INSTABILITY...AVIATION
INTERESTS CAN CURRENTLY ANTICIPATE WIDELY SCATTERED TO SCATTERED
SHOWERS AND THUNDERSTORMS WITH THEIR ASSOCIATED SUB-VFR
CONDITIONS...ALONG WITH THE POTENTIAL OF LATE NIGHT AND EARLY
MORNING AREAS OF LOW CLOUDS AND FOG.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/WSS
SHORT TERM...WSS
LONG TERM...26
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
132 PM EDT SAT AUG 29 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE MID-ATLANTIC REGION WILL BRING FAIR
WEATHER THROUGH TODAY. INCREASING MOISTURE FROM THE GULF OF
MEXICO COULD BRING SHOWERS AND ISOLATED THUNDERSTORMS TO THE AREA
SUNDAY INTO MONDAY. THE REMNANTS OF ERIKA WILL APPROACH FLORIDA
EARLY NEXT WEEK...POSSIBLY TRACKING INTO THE NORTHERN GULF OF MEXICO
AFTERWARD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...A RATHER NICE SATURDAY FORECAST AS LONG AS
ONE DOESN`T MIND THE SUNLIGHT BEING INCREASINGLY FILTERED BY A
GROWING CANOPY OF CIRRUS. THE DEWPOINT HAS CREPT UP FROM YESTERDAY
AND THE HRRR HAD BEEN SUGGESTING THAT A FEW SHOWERS MATERIALIZE OVER
FAR SOUTHERN COUNTIES. SUCCESSIVE RUNS HAVE BACKED OFF ON THIS SO
WILL KEEP THE FORECAST DRY AT THIS TIME-ANYTHING THAT FALLS SHOULD
BE NON-MEASURABLE SPRINKLES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...HIGH PRESSURE WILL BASICALLY DISSIPATE
ACROSS THE AREA SUNDAY AS MID LEVEL LOW PRESSURE...CURRENTLY OVER
THE GULF COAST RAMBLES INTO THE UPSTATE SOUTH CAROLINA REGION.
THIS FEATURE COMBINED WITH THE ANTICYCLONIC FLOW AROUND THE
BERMUDA RIDGE WILL ADVECT MOISTURE LADEN AIR INTO THE REGION. SOME
DIFLUENCE IS ALSO NOTED IN THE AREA. AS PRECIPITABLE WATERS RISE
TO ALMOST TWO INCHES...LOW CHANCE POPS ARE IN THE PICTURE MAINLY
ACROSS SOUTH CAROLINA SUNDAY AND AREA WIDE MONDAY. TEMPERATURES
ARE MOSTLY SEASONABLE WITH HIGHS IN THE MID TO UPPER 80S AND LOWS
IN THE LOWER TO MIDDLE 70S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...EXPECT A DIFFUSE MID LEVEL PATTERN DURING THE
EXTENDED PERIOD WITH A SIMILAR PRESSURE PATTERN. OVERALL THE AREA
REMAINS BETWEEN ATLANTIC RIDGING AND HIGH PRESSURE OUT WEST. WHAT
EVENTUALLY REMAINS OF TROPICAL STORM ERIKA MEANDERS AROUND THE
SOUTHEAST AS A VORT CENTER SEEMINGLY NEVER GOING ANYWHERE. THERMAL
PROFILES REMAIN MOIST HOWEVER AND WITH THE USUAL MESOSCALE
FEATURES...DECENT CHANCE POPS ARE IN THE FORECAST EACH DAY. NO
CHANGES TO THE TEMPERATURE FORECAST WITH READINGS NEAR NORMAL FOR
DAYTIME HIGHS AND SLIGHTLY ABOVE FOR OVERNIGHT LOWS.
&&
.AVIATION /12Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...MOISTURE STREAMING INTO THE AREA FROM THE SOUTH MAINLY
CONFINED TO THE CIRRUS LEVEL MOST OF THE NIGHT. WILL SHOW LOWERING
CEILINGS TOWARDS DAYBREAK, MOST PRONOUNCED OVER SOUTH CAROLINA. WILL
CAP THE FALL TO MVFR THOUGH SOME OF THE MORE AGGRESSIVE MODELS DO
FALL TO IFR AT MYR, CRE, AND EVEN ILM. AT TIME FEEL THIS IS OVERDONE
BUT NEXT SHIFT MAY BE ABLE TO REFINE. WILL ALSO CARRY VCSH TOWARDS
DAYBREAK ALONG SC COAST BUT THE RAIN ITSELF NOT EXPECTED TO LOWER
ANY FLIGHT CATEGORIES AS IT WILL BE QUITE LIGHT.
EXTENDED OUTLOOK...PREDOMINATELY VFR WITH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. BRIEF MORNING
FOG/STRATUS IS ALSO EXPECTED EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM SATURDAY...STILL RATHER
CHOPPY AND WILL LEAVE SCEC AS-IS IN THE CONTINUED MODERATE
NORTHEASTERLY GRADIENT. NO CHANGES TO THE FORECAST AND THE PREVIOUS
DISCUSSION FOLLOWS.
AS OF 630 AM SATURDAY...HAVE RAISED A SMALL CRAFT EXERCISE
CAUTION FLAG FOR ALL WATERS...EXCEPT BETWEEN LITTLE RIVER INLET TO
MURRELLS INLET WHERE ITS SOMEWHAT PROTECTED FROM THE HIGHER NE
WIND WAVES DUE TO THE LOWER FETCH FOR THEM TO GROW.
THE MODEST 1020+ HIGH BROADLY CENTERED FROM OVER THE NC-VA BORDER
TO ACROSS THE MID-ATLANTIC STATES...IS PROGGED TO REMAIN
RELATIVELY IN PLACE THRU THIS NEAR TERM PERIOD. AT THIS SAME
TIME...A WEAK SFC LOW IS PROGGED BY THE MODELS ALONG A STALLED SFC
BOUNDARY ORIENTED NE-SW OFF THE CAROLINA COASTLINES THIS
MORNING...THAT WILL TRACK NE ALONG THIS STALLED FRONT TO A
POSITION OFF CAPE HATTERAS BY DAYBREAK SUNDAY. THE AREA WATERS IS
ALREADY EXPERIENCING A TIGHTENED SFC PG ATTM...AND SHOULD REMAIN
THIS WAY TODAY INTO THIS EVENING PRIOR TO THE LOW EXITING NE OF
THE AREA WATERS. AS A RESULT...THE WATERS WILL OBSERVE A SOLID NE
TO ENE 15 TO 20 KT WIND TODAY...THAT WILL SLOWLY SUBSIDE TO 10-15
KT THIS EVENING AND OVERNIGHT.
SIGNIFICANT SEAS HAVE ALREADY RISEN FROM THE INCREASED NE WINDS
FROM YESTERDAY. WILL BE LOOKING AT A SOLID 3 TO 5 FT INTO EARLY
THIS EVENING...BEFORE DROPPING OFF TO BETWEEN 2 TO 4 FT LATER
TONIGHT. THE EXCEPTION WILL BE THE WATERS BETWEEN LITTLE RIVER
INLET TO MURRELLS INLET WHERE A LIMITED FETCH WILL EXIST FOR
GROWING NE WIND-DRIVEN WAVES. AN UNDERLYING 1 TO 1.5 FOOT ESE
GROUND SWELL AT 10-12 SECOND PERIODS WILL CONTINUE...HOWEVER
THE 4 TO 6 SECOND PERIOD WIND DRIVEN WAVES WILL DOMINATE THE
SIGNIFICANT SEAS SPECTRUM.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...THE NORTHEAST FLOW WILL GIVE WAY TO A
SOUTHEAST FLOW BY MIDDAY SUNDAY AS HIGH PRESSURE GIVES WAY TO
WEAK COASTAL TROUGHING. THE SOUTHEAST FLOW WILL CONTINUE THROUGH
THE END OF THE PERIOD. GUIDANCE IS HINTING AT A FEW HOURS OF NE
WINDS EARLY TUESDAY BUT THIS SHOULD BE FLEETING. SIGNIFICANT SEAS
WILL GENERALLY BE 2-3 FEET.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...RELATIVELY LIGHT WIND FIELDS FOR THE WATERS
WITH WEAK SYNOPTIC FEATURES. OVERALL EXPECT A MOSTLY SOUTHEAST
WIND DIRECTION WITH SPEEDS TEN KNOTS OR LESS. SIGNIFICANT SEAS
WILL BE LIMITED AS WELL WITH 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MBB
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1236 PM CDT SAT AUG 29 2015
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 1124 AM CDT SAT AUG 29 2015/
UPDATE...
MUCH OF THE MIDSOUTH IS CURRENTLY STUCK BETWEEN TWO WEATHER
SYSTEMS. THE FIRST IS AN UPPER TROF THAT IS PUSHING ACROSS NORTH
CENTRAL ARKANSAS AT THIS TIME. AN AREA OF MAINLY SHOWERS IS
ACCOMPANYING THE TROF. HOWEVER THE AREA IS QUICKLY DYING OUT
EXPECT ONLY RANDOLPH AND LAWRENCE COUNTIES IN NORTHEAST ARKANSAS
WILL SEE ANY RAIN. MEANWHILE...AN EASTERLY WAVE IN MOVING THROUGH
ALABAMA. A LINE OF SHOWERS AND THUNDERSTORMS IS CURRENTLY
DEVELOPING ACROSS NORTHWEST ALABAMA. THIS LINE WILL MOVE SLOWLY
NORTHWESTWARD AND COULD IMPACT PORTIONS OF NORTHEAST MISSISSIPPI
THIS AFTERNOON. WILL BUMP UP POPS ACROSS THIS AREA.
OTHERWISE...REST OF THE FORECAST LOOKS GOOD. HIGHS WILL BE IN THE
UPPER 80S TO THE LOWER 90S THIS AFTERNOON.
KRM
PREV DISCUSSION... /ISSUED 440 AM CDT SAT AUG 29 2015/
UPDATE...
UPDATED TO INCREASE THE POPS FOR TODAY TO 40 PERCENT ACROSS
PORTIONS OF NORTHEAST AR THAT INCLUDES RANDOLPH...LAWRENCE AND
EXTREME WESTERN PORTIONS OF CLAY COUNTY. THE HRRR MODEL INDICATES
SHOWERS SPREADING INTO THIS AREA THIS MORNING. RADARS ALREADY
INDICATE SHOWERS JUST TO THE NORTHWEST GRADUALLY SLIPPING TO THE
SOUTHEAST.
JCL
DISCUSSION... /ISSUED 348 AM CDT SAT AUG 29 2015/
EARLY THIS MORNING...TEMPERATURES WERE A LITTLE WARMER THAN IN
RECENT DAYS RANGING FROM THE MIDDLE 60S TO LOWER 70S. MIDDLE AND
HIGH LEVEL CLOUDS STRETCHED FROM NORTHWEST TN AND THE MO BOOTHEEL
INTO NORTHEAST AR.
THE MIDSOUTH WILL BE AFFECTED BY TWO SYSTEMS THE NEXT COUPLE OF
DAYS...ONE AN UPPER LEVEL TROUGH APPROACHING FROM THE NORTHWEST
AND ANOTHER AN UPPER LEVEL LOW ALONG THE NORTHERN GULF COAST THAT
WILL LIFT NORTHEASTWARD. BOTH OF THESE FEATURES ARE FAIRLY WEAK.
THE LATEST GUIDANCE INDICATES HIGHER POPS ESPECIALLY FOR TONIGHT
AND SUNDAY THAN THE EARLIER GUIDANCE...DID RAISE THE POPS SOME BUT
CONFIDENCE IS NOT HIGH ENOUGH TO GO GREATER THAN 30 PERCENT POPS
ATTM. LATER FORECASTS MAY NEED TO RAISE THE POPS IN SOME LOCATIONS
DURING THIS TIMEFRAME.
FOR TODAY...AN UPPER LEVEL TROUGH FROM THE GREAT LAKES TO THE
CENTRAL PLAINS WILL MOVE SOUTHEASTWARD APPROACHING NORTHEAST AR.
INDICATED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR A SMALL
PORTION OF NORTHEAST AR TODAY. MEANWHILE...AN UPPER LEVEL LOW
WILL BE LOCATED ALONG THE MS AND AL COAST. THIS LOW WILL HELP TO
PUSH MORE MOIST AND UNSTABLE AIR INTO THE MIDSOUTH FROM THE EAST.
CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
FOR NORTHEAST MS AND THE TN RIVER VALLEY OF WEST TN. CLOUDS WILL
BE ON THE INCREASE ACROSS THE MIDSOUTH IN ASSOCIATION WITH BOTH OF
THESE SYSTEMS. TEMPERATURES WILL BE SEASONABLY WARM.
FOR TONIGHT...THE UPPER LEVEL TROUGH WILL PUSH INTO THE MIDSOUTH
FROM THE NORTHWEST WITH THE UPPER LOW ALONG THE CENTRAL GULF COAST
MOVING NORTHEASTWARD INTO CENTRAL AL. INDICATED A CHANCE OF
SHOWERS AND THUNDERSTORMS FOR MOST OF THE REGION.
ON SUNDAY...THE UPPER LEVEL LOW OVER CENTRAL AL WILL CONTINUE TO
PUSH NORTHEASTWARD WITH A WEAK BROAD UPPER LEVEL TROUGH OVER THE
MIDSOUTH. CONTINUED TO MENTION A CHANCE OF SHOWERS AND
THUNDERSTORMS. CLOUDS ARE EXPECTED TO DECREASE FROM THE SOUTHWEST.
MONDAY...AN UPPER LEVEL TROUGH WILL BE WEST OF THE MIDSOUTH WHILE
UPPER LEVEL RIDGING WILL BE TO THE EAST WITH WEAK SOUTHERLY FLOW
SURFACE AND ALOFT ACROSS THE REGION. THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY FOR A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS.
IT WILL FEEL LIKE SUMMER WITH PLENTY OF SUNSHINE BOOSTING
TEMPERATURES TO NEAR NORMAL READINGS.
TUESDAY...THE UPPER LEVEL RIDGE IS FORECAST TO BUILD ACROSS THE
MIDSOUTH FROM THE EAST SUPPRESSING MOST CONVECTION. KEPT POPS
BELOW MENTIONABLE LEVELS.
TOWARD THE MIDDLE AND END OF NEXT WEEK...INCREASING MOISTURE IS
FORECAST TO SPREAD INTO THE REGION FROM THE SOUTHEAST AS UPPER
LEVEL RIDGING WEAKENS. THIS WILL RESULT IN A RETURN OF A SMALL
CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. TEMPERATURES WILL
REMAIN SEASONABLY WARM TO HOT WITH NO COLD FRONTAL PASSAGES
EXPECTED.
JCL
&&
.AVIATION...
18Z TAF CYCLE
VFR. SHRAS WEST OF KJBR WILL CONTINUE TO DISSIPATE AS THEY MOVE
EAST TOWARD EASTERN ARKANSAS. ANOTHER DEVELOPING AREA OF
SHRA/TSRAS ACROSS NORTHWEST ALABAMA COULD PUSH NW INTO NORTHEAST
MISSISSIPPI THIS AFTERNOON THOUGH CONFIDENCE IS TOO LOW TO
MENTION VCTS/VCSH AT KTUP ATTM. SOUTH WINDS AROUND 8 KTS WILL
DIMINISH TO 5 KTS OR LESS OVERNIGHT.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1124 AM CDT SAT AUG 29 2015
.UPDATE...
MUCH OF THE MIDSOUTH IS CURRENTLY STUCK BETWEEN TWO WEATHER
SYSTEMS. THE FIRST IS AN UPPER TROF THAT IS PUSHING ACROSS NORTH
CENTRAL ARKANSAS AT THIS TIME. AN AREA OF MAINLY SHOWERS IS
ACCOMPANYING THE TROF. HOWEVER THE AREA IS QUICKLY DYING OUT
EXPECT ONLY RANDOLPH AND LAWRENCE COUNTIES IN NORTHEAST ARKANSAS
WILL SEE ANY RAIN. MEANWHILE...AN EASTERLY WAVE IN MOVING THROUGH
ALABAMA. A LINE OF SHOWERS AND THUNDERSTORMS IS CURRENTLY
DEVELOPING ACROSS NORTHWEST ALABAMA. THIS LINE WILL MOVE SLOWLY
NORTHWESTWARD AND COULD IMPACT PORTIONS OF NORTHEAST MISSISSIPPI
THIS AFTERNOON. WILL BUMP UP POPS ACROSS THIS AREA.
OTHERWISE...REST OF THE FORECAST LOOKS GOOD. HIGHS WILL BE IN THE
UPPER 80S TO THE LOWER 90S THIS AFTERNOON.
KRM
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT SAT AUG 29 2015/
UPDATE...
UPDATED TO INCREASE THE POPS FOR TODAY TO 40 PERCENT ACROSS
PORTIONS OF NORTHEAST AR THAT INCLUDES RANDOLPH...LAWRENCE AND
EXTREME WESTERN PORTIONS OF CLAY COUNTY. THE HRRR MODEL INDICATES
SHOWERS SPREADING INTO THIS AREA THIS MORNING. RADARS ALREADY
INDICATE SHOWERS JUST TO THE NORTHWEST GRADUALLY SLIPPING TO THE
SOUTHEAST.
JCL
&&
.DISCUSSION... /ISSUED 348 AM CDT SAT AUG 29 2015/
EARLY THIS MORNING...TEMPERATURES WERE A LITTLE WARMER THAN IN
RECENT DAYS RANGING FROM THE MIDDLE 60S TO LOWER 70S. MIDDLE AND
HIGH LEVEL CLOUDS STRETCHED FROM NORTHWEST TN AND THE MO BOOTHEEL
INTO NORTHEAST AR.
THE MIDSOUTH WILL BE AFFECTED BY TWO SYSTEMS THE NEXT COUPLE OF
DAYS...ONE AN UPPER LEVEL TROUGH APPROACHING FROM THE NORTHWEST
AND ANOTHER AN UPPER LEVEL LOW ALONG THE NORTHERN GULF COAST THAT
WILL LIFT NORTHEASTWARD. BOTH OF THESE FEATURES ARE FAIRLY WEAK.
THE LATEST GUIDANCE INDICATES HIGHER POPS ESPECIALLY FOR TONIGHT
AND SUNDAY THAN THE EARLIER GUIDANCE...DID RAISE THE POPS SOME BUT
CONFIDENCE IS NOT HIGH ENOUGH TO GO GREATER THAN 30 PERCENT POPS
ATTM. LATER FORECASTS MAY NEED TO RAISE THE POPS IN SOME LOCATIONS
DURING THIS TIMEFRAME.
FOR TODAY...AN UPPER LEVEL TROUGH FROM THE GREAT LAKES TO THE
CENTRAL PLAINS WILL MOVE SOUTHEASTWARD APPROACHING NORTHEAST AR.
INDICATED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR A SMALL
PORTION OF NORTHEAST AR TODAY. MEANWHILE...AN UPPER LEVEL LOW
WILL BE LOCATED ALONG THE MS AND AL COAST. THIS LOW WILL HELP TO
PUSH MORE MOIST AND UNSTABLE AIR INTO THE MIDSOUTH FROM THE EAST.
CONTINUED TO INDICATE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
FOR NORTHEAST MS AND THE TN RIVER VALLEY OF WEST TN. CLOUDS WILL
BE ON THE INCREASE ACROSS THE MIDSOUTH IN ASSOCIATION WITH BOTH OF
THESE SYSTEMS. TEMPERATURES WILL BE SEASONABLY WARM.
FOR TONIGHT...THE UPPER LEVEL TROUGH WILL PUSH INTO THE MIDSOUTH
FROM THE NORTHWEST WITH THE UPPER LOW ALONG THE CENTRAL GULF COAST
MOVING NORTHEASTWARD INTO CENTRAL AL. INDICATED A CHANCE OF
SHOWERS AND THUNDERSTORMS FOR MOST OF THE REGION.
ON SUNDAY...THE UPPER LEVEL LOW OVER CENTRAL AL WILL CONTINUE TO
PUSH NORTHEASTWARD WITH A WEAK BROAD UPPER LEVEL TROUGH OVER THE
MIDSOUTH. CONTINUED TO MENTION A CHANCE OF SHOWERS AND
THUNDERSTORMS. CLOUDS ARE EXPECTED TO DECREASE FROM THE SOUTHWEST.
MONDAY...AN UPPER LEVEL TROUGH WILL BE WEST OF THE MIDSOUTH WHILE
UPPER LEVEL RIDGING WILL BE TO THE EAST WITH WEAK SOUTHERLY FLOW
SURFACE AND ALOFT ACROSS THE REGION. THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY FOR A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS.
IT WILL FEEL LIKE SUMMER WITH PLENTY OF SUNSHINE BOOSTING
TEMPERATURES TO NEAR NORMAL READINGS.
TUESDAY...THE UPPER LEVEL RIDGE IS FORECAST TO BUILD ACROSS THE
MIDSOUTH FROM THE EAST SUPPRESSING MOST CONVECTION. KEPT POPS
BELOW MENTIONABLE LEVELS.
TOWARD THE MIDDLE AND END OF NEXT WEEK...INCREASING MOISTURE IS
FORECAST TO SPREAD INTO THE REGION FROM THE SOUTHEAST AS UPPER
LEVEL RIDGING WEAKENS. THIS WILL RESULT IN A RETURN OF A SMALL
CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. TEMPERATURES WILL
REMAIN SEASONABLY WARM TO HOT WITH NO COLD FRONTAL PASSAGES
EXPECTED.
JCL
&&
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH LIGHT SSE
WINDS.
TVT
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
316 PM CDT SAT AUG 29 2015
.SHORT TERM...
TONIGHT - CONFIDENCE...MEDIUM
MID LEVEL TROUGH AXIS SHIFTING SOUTHEAST OF WI. MEANWHILE THE LOW
LEVELS REMAIN MOIST WITH LITTLE STIRRING OR CHANGE OF AIRMASS. A
WEAK INVERTED TROUGH EXTENDS INTO WI. WIDESPREAD STRATUS HAS A
PRETTY FIRM GRIP ON CENTRAL AND SOUTHERN WI. SOME BREAKS AND THIN
SPOTS HAVE TRIED TO TAKE SHAPE WITHIN SUBSIDENCE REGION OF EXITING
SHORTWAVE HOWEVER THIS HAS BEEN SLOW TO EVOLVE WITH OVC CONDITIONS
BEING PREVALENT. EXPECTING THIS REGIME TO CHANGE LITTLE INTO THE
OVERNIGHT HOURS AS THE COLUMN REMAINS FREE OF WIND IN THE SURFACE-
850 MILLIBAR LAYER. EXPECT FOG TO BECOME A BIT THICKER AS THE NIGHT
WEARS ON BUT CONFIDENCE NOT GREAT THAT WIDESPREAD DENSE FOG WILL
BECOME AN ISSUE DUE TO THE ONGOING STRATUS FIELD. ANY BREAKS THAT
EVOLVE WOULD EXPECT STRATUS/FOG TO FILL RIGHT BACK IN. WITH THE
CLOUD COVER LITTLE TEMP DROPOFF EXPECTED.
.SUNDAY - CONFIDENCE...MEDIUM
MID LEVEL RIDGING TAKES HOLD WITH SURFACE HIGH DOMINATING IN THE LOW
LEVELS. AGAIN NOT MUCH STIRRING SO EROSION OF MORNING FOG/STRATUS MAY
BE A SLOW PROCESS. 925 THERMAL TROUGH EASES A BIT WITH WINDS TURNING
MORE SW AND 850 SHOWS SOME WARMING AS WELL. SO ONCE THE SUN BREAKS
THROUGH EXPECT TEMPS TO GET BACK INTO THE 70S WITH PERHAPS AN 80 OR
TWO IN WESTERN CWA WHERE LINGERING STRATUS LIKELY TO ERODE SOONEST.
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE HIGH.
THE UPPER RIDGE OVER THE PLAINS WILL ROLL OVER INTO THE GREAT
LAKES FOR SUN NT AND MON. THE SFC HIGH WILL MOVE SLIGHTLY TO THE
EAST OF THE REGION WITH A SLY FLOW DEVELOPING. 925 MB TEMPS WILL
RISE TO 23-24C BY LATE AFTERNOON ON MON WHICH YIELDS HIGHS IN THE
MID TO UPPER 80S AWAY FROM THE LAKE BREEZE. THE UPPER RIDGE WILL
FLATTEN AND MOVE TO THE MID ATLANTIC STATES FOR TUE WITH A SWLY
FLOW ALOFT FROM THE WRN USA INTO THE NRN GREAT LAKES. IT APPEARS
ANY EMBEDDED WEAK SHORTWAVE TROUGHS WILL REMAIN TO THE WEST SO THE
DRY FCST CONTINUES. HIGH TEMPS MID TO UPPER 80S WILL CONTINUE
EXCEPT NEAR LAKE MI.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE
MEDIUM.
THE MEAN UPPER TROUGH WILL REMAIN OVER WRN CANADA AND THE PACIFIC
NW WITH A BROAD RIDGE OVER MUCH OF THE CENTRAL AND ERN USA. WEAK
SHORTWAVE TROUGHS HOWEVER WILL FLATTEN THE RIDGE AT TIMES AND
BRING SLIGHT CHANCES OF TSTORMS TO THE REGION FROM WED-SAT. VERY
WARM AND HUMID CONDITIONS WILL CONTINUE.
&&
.AVIATION/00Z TAFS/...VERY WEAK 925/850 FLOW THROUGH TONIGHT AND
INTO EARLY SUNDAY AS WELL. SUBSIDENCE WITH PASSING SHORTWAVE NOT
DOING MUCH TO ERODE THE CLOUD COVER. RAP SOUNDINGS LOOK TO DRY
THINGS OUT LATER TODAY AND THIS EVENING BUT THAT CONTINUES TO LOOK
OPTIMISTIC. LEANING MORE TOWARDS THE METMOS GUID GIVEN PRESENT VSBL
IMAGERY/SFC OBS. STRATUS LIKELY TO KEEP VSBYS FROM GETTING
WIDESPREAD DENSE THOUGH LOW LEVELS ARE MORE MOIST DUE TO THE RECENT
RAINS. BUT STILL EXPECTING A GOOD DEAL OF LIFR CONDITIONS. THE
WIDESPREAD STRATUS/FOG IS LIKELY TO PERSIST INTO SUNDAY MORNING.
THEN AS SOME WEAK WAA TAKES HOLD EXPECTING SOME EROSION TO TAKE
PLACE WITH GRADUALLY IMPROVING CIGS/VSBYS AS THE DAY WEARS ON.
&&
.MARINE...WITH A LIGHT WIND REGIME AND A MOIST AIRMASS REMAINING IN
PLACE HAVE HOISTED A DENSE FOG ADVISORY UNTIL 10 AM SUNDAY. FOG
WILL BE REMAIN POSSIBLE AT TIMES OVER LAKE MI FOR THE NEW WEEK
DUE TO A HUMID AND STAGNANT AIRMASS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 10 AM CDT SUNDAY FOR LMZ643>646.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...GEHRING