Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/15/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
327 PM MST SUN SEP 13 2015
.SYNOPSIS...
SEVERAL PACIFIC WEATHER DISTURBANCES WILL MOVE THROUGH THE REGION
THE FIRST HALF OF THIS WEEK KEEPING STORM CHANCES GOING...MAINLY EAST
OF THE LOWER COLORADO RIVER VALLEY. BEST CHANCES LOOK TO BE TONIGHT
INTO MONDAY NIGHT. BY THURSDAY...DRIER AND STABLE AIR TAKES OVER.
TEMPERATURES WILL DROP SEVERAL DEGREES BELOW NORMAL BEFORE WARMING A
FEW DEGREES DURING THE LATTER HALF OF THE WEEK.
&&
.DISCUSSION...
REST OF TODAY/TONIGHT...
THE SHORT WAVE IS BEGINNING TO TRANSITION INTO NORTHERN ARIZONA. THE
CLOUDINESS WITH IT HAS THINNED DOWN QUITE A BIT AS WELL. CONVECTION
HAS BEGUN OVER HIGHER TERRAIN AREAS INCLUDING OUR FORECAST ZONE
24...SOUTHERN GILA AND FAR NORTHEAST MARICOPA COUNTIES. AFTERNOON
TEMPERATURES ARE RUNNING SEVERAL DEGREES WARMER OVER MUCH OF
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA COMPARED TO 24 HOURS AGO.
CONVERSELY...THE CENTRAL DESERTS HAVE BEEN RUNNING COOLER DUE TO THE
EARLIER CLOUD COVER. DEW POINTS HAVE DROPPED INTO THE 50S AT MOST
LOWER DESERT LOCATIONS DUE TO DAYTIME MIXING. TEMP/DEW POINT SPREADS
WILL BE SUFFICIENT FOR EVAPORATIVELY ENHANCED DOWNDRAFTS AND IN TURN
OUTFLOW BOUNDARIES WHICH COULD INITIATE NEW STORMS. HI-RES MODELS
INCLUDING HRRR AND AND U OF A WRF/S ARE DEPICTING THAT SCENARIO TO
VARYING DEGREES SUCH THAT STORMS FROM ZONE 24 AND AREAS OUTSIDE OF
OUR CWA SPAWN DEVELOPMENT OVER THE SOUTH-CENTRAL DESERTS THIS
EVENING. MADE AN EARLIER ADJUSTMENT TO DECREASE THE AFTERNOON POPS
OVER THE PHOENIX AREA BUT INCREASE THE EVENING POPS. A CAVEAT IS THAT
MODEST LOWER LEVEL MOISTURE TENDS TO INHIBIT WIDESPREAD STORM
DEVELOPMENT. AS MENTIONED IN PREVIOUS DISCUSSION...THERE IS SOME
DYNAMICAL ASSISTANCE TODAY WITH AN UPPER LEVEL SHORT WAVE COINCIDING
WITH THE LEFT EXIT REGION OF A JET STREAK...MAINLY BENEFITING
NORTHERN ARIZONA.
MONDAY THROUGH WEDNESDAY...
THE UPPER TROUGH/LOW CENTERED NEAR THE S.F. BAY AREA WILL WEAKEN AND
GET KICKED EASTWARD BY A LARGER UPSTREAM TROUGH MONDAY. IT WILL COME
THROUGH OUR AREA LATER IN THE DAY AS A SHORT WAVE/VORT MAX WITH A
DIVQ BULLSEYE. WHILE THE MODELS SHOW MOIST ADVECTION TAKING PLACE
OVERNIGHT...THEY ARE CONSERVATIVE WITH THE CAPE WHICH IS DUE AT LEAST
IN PART TO WARMING ALOFT. THE MODELS ARE ALSO SHOWING THAT THE VORT
MAXW WILL LAG BEHIND THE BETTER MOISTURE BY THE TIME IT MOVES IN.
THUS POPS ARE SOMEWHAT CONSERVATIVE GIVEN THE SYNOPTIC PATTERN.
STORMS THAT DO FORM WILL HAVE SOME VERTICAL WIND SHEAR TO OPERATE IN
WHICH AIDS LONGEVITY. TUESDAY IS SOMETHING OF A REPEAT OF MONDAY IN
THAT THE UPPER TROUGH MOVES INLAND AND WEAKENS BUT IT WEAKENS EVEN
FASTER AND HAS LESS OF A LEFTOVER SHORT WAVE. THUS POPS ARE LOWER FOR
TUESDAY THAN MONDAY. ON WEDNESDAY...YET ANOTHER UPPER TROUGH MOVES
INLAND WHICH HELPS ADVECT SOME MOISTURE FROM THE EAST PACIFIC.
HOWEVER...IT IS HAVING TO OVERCOME DRY AIR. THE END RESULT IS THAT
THERE ARE ONLY SLIGHT CHANCE POPS OVER PORTIONS OF SOUTH-CENTRAL
ARIZONA. WITH TROUGHING PUSHING THE RIDGE TO THE EAST...TEMPERATURES
TREND DOWN SEVERAL DEGREES BELOW NORMAL.
THURSDAY THROUGH SUNDAY...
ALTHOUGH STRONG UPPER LEVEL SOUTHWEST WINDS WILL CONTINUE...DUE TO
ADDITIONAL PACIFIC SHORTWAVES FLOWING WELL NORTH OF THE AREA...
MODELS INSIST THAT A STABLE AND WARM AIRMASS WILL PRECLUDE ANY SHWR
ACTIVITY. AFTN TEMPS THESE DAYS SHOULD BE NEAR NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MODERATE CONFIDENCE EXISTS REGARDING TS APPROACHING PHOENIX
TERMINALS LATE AFTERNOON/EARLY EVENING SUNDAY. WHILE CONFIDENCE IS
LOWER IN TS DIRECTLY HITTING ANY GIVEN AIRFIELD...IMPACTS FROM
SHIFTING STRONGER OUTFLOW WINDS WILL BE MORE LIKELY.
HOWEVER...TIMING WIND DIRECTIONS AND SPEEDS WILL BECOME PROBLEMATIC
DUE TO A GREATER LIKELIHOOD OF SEVERAL OUTFLOWS INTERSECTING ACROSS
THE PHOENIX METRO. MODELS SUGGEST TS MOVING INTO THE PHOENIX AREA
AROUND 00Z...THOUGH HAVE DELAYED ARRIVAL OF VCTS IN TAF PACKAGE BY
AN HOUR OR TWO. OTHERWISE...CIGS SHOULD GENERALLY REMAIN AOA 10K FT
THROUGH MONDAY MORNING.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
MODERATE CONFIDENCE THAT AVIATION IMPACTS SHOULD BE LIMITED TO WINDS
ACROSS SOUTHEAST CALIFORNIA THROUGH TUESDAY MORNING AS TS ACTIVITY
SHOULD REMAIN OVER EAST CNTRL ARIZONA...AND WEST OVER THE MOUNTAINS
OF FAR SW CALIFORNIA AND THE BAJA SPINE. A BRIEF PERIOD OF GUSTY
WEST WINDS AFTER SUNSET WILL BE POSSIBLE AT KIPL...WITH A GENERAL
PREVAILING SOUTH SFC WIND AT KBLH. MUCH STRONGER WINDS WILL BE
POSSIBLE AFTER THIS VALID TAF PERIOD MONDAY LATE AFTERNOON/EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
MOISTURE WILL STEADILY DECLINE BEGINNING WEDNESDAY WITH LITTLE TO NO
CHANCE OF WETTING RAINFALL THROUGH THE WEEKEND. WITH TEMPERATURES
NOT STRAYING TOO FAR FROM AVERAGE FOR MID SEPTEMBER...AFTERNOON
MINIMUM HUMIDITY VALUES WILL FALL INTO A 15 TO 30 PERCENT RANGE.
OVERNIGHT RECOVERY WILL GENERALLY BE GOOD. WINDS WILL TEND TO BE
SOMEWHAT GUSTY FROM THE WEST DURING THE AFTERNOON
HOURS...PARTICULARLY WEDNESDAY...WITH A TENDENCY FOR A LIGHT
DRAINAGE COMPONENT OVERNIGHT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT ACCORDING TO STANDARD PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ/VASQUEZ
AVIATION...MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1150 AM MST SUN SEP 13 2015
...UPDATED AVIATION AND FIRE WEATHER...
.SYNOPSIS...
SEVERAL PACIFIC WEATHER DISTURBANCES WILL MOVE INTO THE REGION TODAY
THROUGH TUESDAY...WITH A MODEST INCREASE IN MOISTURE AND CHANCES FOR
SHOWERS OR THUNDERSTORMS. THESE DISTURBANCES WILL ALSO ALLOW
TEMPERATURES TO FALL SLIGHTLY BELOW AVERAGE DURING THE FIRST PAST OF
THE WEEK. A MUCH DRIER AND STABLE AIRMASS WILL RETURN FOR THE LATTER
HALF OF NEXT WEEK.
&&
.DISCUSSION...
A BATCH OF MID AND HIGH CLOUDS OVER PORTIONS OF ARIZONA INCLUDING
PHOENIX METRO IS ASSOCIATED WITH A SHORT WAVE WHICH HAS AT LEAST ONE
OR TWO VORT MAXES EMBEDDED WITHIN IT. AT LEAST SOME OF THE CLOUD
MATERIAL IS DEBRIS FROM CONVECTION LAST NIGHT. THIS SHORT WAVE IS
BEING PUSHED SLOWLY NORTH-NORTHEASTWARD BY A LOW PRESSURE SYSTEM
CENTERED NEAR THE S.F. BAY AREA THIS MORNING. AREA SOUNDINGS THIS
MORNING SHOW SIGNIFICANT 24 HOUR MOISTENING IN THE 1000-700 MB LAYER
AT VEF AND FGZ WITH LESS INCREASE AT TWC AND VERY LITTLE CHANGE AT
PSR. NO SOUNDING AVAILABLE FROM 1Y7/8/9. ONE NOTABLE CHANGE HOWEVER
IS COOLING NEAR AND ABOVE 500 MB. SO IF PARCELS CAN REACH THE LFC
THERE WOULD BE MORE CAPE AVAILABLE. HOWEVER...AS THE SHORT WAVE AXIS
SHIFTS NORTH-NORTHEASTWARD...SOMEWHAT WARMER AIR ALOFT WILL BE
ADVECTED IN. SOMETHING THAT WOULD HAVE A MORE SIGNIFICANT IMPACT ON
CAPE IS DECLINING MOISTURE IN THE LOWER LEVELS AS IS FORECAST BY
MULTIPLE MODELS FOR THIS AFTERNOON. MEANWHILE...AN UPPER LEVEL SHORT
WAVE WILL BE TRAVERSING THE MOHAVE DESERT AND MOVING THROUGH MAINLY
NORTHERN ARIZONA. MODELS DEPICT VARYING DEGREES OF UPPER DIVERGENCE
AFFECTING OUR AREA...MAINLY SOUTH-CENTRAL ARIZONA...WITH THE BULK OF
IT TO OUR NORTH. LATEST RAP RUNS SHOW QUITE A BIT OF UPPER
DIVERGENCE OVER NORTHERN AND EAST-CENTRAL ARIZONA INCLUDING OUR ZONE
24 AND GO ON TO INDICATE CONVECTION PROPAGATING TO THE LOWER
DESERTS THIS EVENING...LARGELY AGAINST THE STEERING FLOW. POPS OVER
PHOENIX AREA MAY BE A BIT OVERDONE PRIOR TO LATE AFTERNOON/EARLY
EVENING DUE TO CLOUD COVER. HOWEVER...WITH VORTICITY AROUND THERE
COULD BE POP UP SHOWERS. MAY NEED TO MAKE SOME TWEAKS TO POPS AND
TEMPS BUT NO MAJOR SURGERY. MORE LATER.
&&
.PREVIOUS DISCUSSION ISSUED 245 AM...
TODAY AND MONDAY...
FORECASTS WILL BECOME A LITTLE TRICKY THESE DAYS AS SEVERAL PACIFIC
SHORTWAVES MOVE INTO THE REGION...OVER A WARM MOIST AIRMASS...AND
WITH A VERTICAL WIND SHEARED ENVIRONMENT MAINLY WESTERN AZ MONDAY.
AT 08Z A SMALL NEGATIVE TILT DIFLUENT TROF WAS SEEN MOVING ASHORE IN
CENTRAL AZ...AND FORECAST TO MOVE QUICKLY SOUTHEASTWARD INTO CENTRAL
AZ THIS MORNING AND AFTERNOON. ALSO AT 08Z...STARTING EARLY WERE A
FEW TSTMS ON RADAR NEAR BUCKEYE...GENERALLY IN FAR WEST PHOENIX WITH
TOPS TO 40 THSD FT. A CHANCE OF SHOWERS AND THUNDERSTORMS ARE
FORECAST ACROSS PARTS OF SOUTHWEST AND SOUTH CENTRAL ARIZONA THROUGH
THIS EVENING.
RECENT MODEL FORECASTS FOR MONDAY HAVE AMPLIFIED A SECOND MORE
ENERGETIC TROF TO MOVE INTO NORTHWEST AZ BY LATE AFTERNOON.
SIGNIFICANT DIFLUENT FLOW ALOFT IS FORECAST TO DEVELOP OVER PARTS OF
SOUTHWEST AND SOUTH CENTRAL AZ...GENERALLY NORTH OF A LINE FROM
PHOENIX TO BLYTHE CA. MODELS ARE CONSISTENT WITH FORECASTS OF
MODERATELY STRONG 850/700 20-30 KT SOUTHERLY WINDS AHEAD OF THE TROF
IN FAR WESTERN ARIZONA...WITH GOOD WIND VEERING PROFILES WITH HEIGHT
CHARACTERISTICALLY ASSOCIATED WITH ORGANIZED CONVECTION. THERE IS
ONE CAVEAT THOUGH. MODELS FORECAST A PLUME OF WARM MID LEVEL
TEMPERATURES TO MOVE INTO WEST CENTRAL AND SOUTHWEST AZ THAT COULD
STABILIZE THE AIRMASS. SPC IN THEIR CONVECTIVE OUTLOOK FOR DAY 2
(MONDAY)...HAVE NEARLY ALL OF AZ IN GENERAL TSTM POTENTIAL.
THEREFORE DUE TO THIS ENERGETIC TROF...AND CONCERNS ABOUT POTENTIAL
SHWR COVERAGE AND INTENSITY...WE WILL CONTINUE WITH A CHANCE OF
SHOWERS AND THUNDERSTORMS OVER PARTS OF SOUTHWEST AND SOUTH CENTRAL
AZ...INCLUDING PHOENIX.
TUESDAY...
NOT SURE ABOUT TUESDAY. VERY STRONG SOUTHWESTERLY FLOW ALOFT
ASSOCIATED WITH ANOTHER PACIFIC SHORTWAVE FORECAST TO MOVE ACROSS
FAR NORTHERN AZ COULD RESULT IN SHOWER POTENTIAL IN SOUTH CENTRAL.
CONFIDENCE IS LOW. THEREFORE WE WILL CONTINUE WITH A SLIGHT CHANCE
OF SHOWERS AND TSTMS GENERALLY FROM PHOENIX EASTWARD.
WEDNESDAY THROUGH SUNDAY...
ALTHOUGH STRONG UPPER LEVEL SOUTHWEST WINDS WILL CONTINUE...DUE TO
ADDITIONAL PACIFIC SHORTWAVES FLOWING WELL NORTH OF THE AREA...
MODELS INSIST THAT A STABLE AND WARM AIRMASS WILL PRECLUDE ANY SHWR
ACTIVITY. AFTN TEMPS THESE DAYS SHOULD BE NEAR NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MODERATE CONFIDENCE EXISTS REGARDING TS APPROACHING PHOENIX
TERMINALS LATE AFTERNOON/EARLY EVENING SUNDAY. WHILE CONFIDENCE IS
LOWER IN TS DIRECTLY HITTING ANY GIVEN AIRFIELD...IMPACTS FROM
SHIFTING STRONGER OUTFLOW WINDS WILL BE MORE LIKELY.
HOWEVER...TIMING WIND DIRECTIONS AND SPEEDS WILL BECOME PROBLEMATIC
DUE TO A GREATER LIKELIHOOD OF SEVERAL OUTFLOWS INTERSECTING ACROSS
THE PHOENIX METRO. MODELS SUGGEST TS MOVING INTO THE PHOENIX AREA
AROUND 00Z...THOUGH HAVE DELAYED ARRIVAL OF VCTS IN TAF PACKAGE BY
AN HOUR OR TWO. OTHERWISE...CIGS SHOULD GENERALLY REMAIN AOA 10K FT
THROUGH MONDAY MORNING.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
MODERATE CONFIDENCE THAT AVIATION IMPACTS SHOULD BE LIMITED TO WINDS
ACROSS SOUTHEAST CALIFORNIA THROUGH TUESDAY MORNING AS TS ACTIVITY
SHOULD REMAIN OVER EAST CNTRL ARIZONA...AND WEST OVER THE MOUNTAINS
OF FAR SW CALIFORNIA AND THE BAJA SPINE. A BRIEF PERIOD OF GUSTY
WEST WINDS AFTER SUNSET WILL BE POSSIBLE AT KIPL...WITH A GENERAL
PREVAILING SOUTH SFC WIND AT KBLH. MUCH STRONGER WINDS WILL BE
POSSIBLE AFTER THIS VALID TAF PERIOD MONDAY LATE AFTERNOON/EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
MOISTURE WILL STEADILY DECLINE BEGINNING WEDNESDAY WITH LITTLE TO NO
CHANCE OF WETTING RAINFALL THROUGH THE WEEKEND. WITH TEMPERATURES
NOT STRAYING TOO FAR FROM AVERAGE FOR MID SEPTEMBER...AFTERNOON
MINIMUM HUMIDITY VALUES WILL FALL INTO A 15 TO 30 PERCENT RANGE.
OVERNIGHT RECOVERY WILL GENERALLY BE GOOD. WINDS WILL TEND TO BE
SOMEWHAT GUSTY FROM THE WEST DURING THE AFTERNOON
HOURS...PARTICULARLY WEDNESDAY...WITH A TENDENCY FOR A LIGHT
DRAINAGE COMPONENT OVERNIGHT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT ACCORDING TO STANDARD PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
930 AM MST SUN SEP 13 2015
.SYNOPSIS...
SEVERAL PACIFIC WEATHER DISTURBANCES WILL MOVE INTO THE REGION TODAY
THROUGH TUESDAY...WITH A MODEST INCREASE IN MOISTURE AND CHANCES FOR
SHOWERS OR THUNDERSTORMS. THESE DISTURBANCES WILL ALSO ALLOW
TEMPERATURES TO FALL SLIGHTLY BELOW AVERAGE DURING THE FIRST PAST OF
THE WEEK. A MUCH DRIER AND STABLE AIRMASS WILL RETURN FOR THE LATTER
HALF OF NEXT WEEK.
&&
.DISCUSSION...
A BATCH OF MID AND HIGH CLOUDS OVER PORTIONS OF ARIZONA INCLUDING
PHOENIX METRO IS ASSOCIATED WITH A SHORT WAVE WHICH HAS AT LEAST ONE
OR TWO VORT MAXES EMBEDDED WITHIN IT. AT LEAST SOME OF THE CLOUD
MATERIAL IS DEBRIS FROM CONVECTION LAST NIGHT. THIS SHORT WAVE IS
BEING PUSHED SLOWLY NORTH-NORTHEASTWARD BY A LOW PRESSURE SYSTEM
CENTERED NEAR THE S.F. BAY AREA THIS MORNING. AREA SOUNDINGS THIS
MORNING SHOW SIGNIFICANT 24 HOUR MOISTENING IN THE 1000-700 MB LAYER
AT VEF AND FGZ WITH LESS INCREASE AT TWC AND VERY LITTLE CHANGE AT
PSR. NO SOUNDING AVAILABLE FROM 1Y7/8/9. ONE NOTABLE CHANGE HOWEVER
IS COOLING NEAR AND ABOVE 500 MB. SO IF PARCELS CAN REACH THE LFC
THERE WOULD BE MORE CAPE AVAILABLE. HOWEVER...AS THE SHORT WAVE AXIS
SHIFTS NORTH-NORTHEASTWARD...SOMEWHAT WARMER AIR ALOFT WILL BE
ADVECTED IN. SOMETHING THAT WOULD HAVE A MORE SIGNIFICANT IMPACT ON
CAPE IS DECLINING MOISTURE IN THE LOWER LEVELS AS IS FORECAST BY
MULTIPLE MODELS FOR THIS AFTERNOON. MEANWHILE...AN UPPER LEVEL SHORT
WAVE WILL BE TRAVERSING THE MOHAVE DESERT AND MOVING THROUGH MAINLY
NORTHERN ARIZONA. MODELS DEPICT VARYING DEGREES OF UPPER DIVERGENCE
AFFECTING OUR AREA...MAINLY SOUTH-CENTRAL ARIZONA...WITH THE BULK OF
IT TO OUR NORTH. LATEST RAP RUNS SHOW QUITE A BIT OF UPPER
DIVERGENCE OVER NORTHERN AND EAST-CENTRAL ARIZONA INCLUDING OUR ZONE
24 AND GO ON TO INDICATE CONVECTION PROPAGATING TO THE LOWER
DESERTS THIS EVENING...LARGELY AGAINST THE STEERING FLOW. POPS OVER
PHOENIX AREA MAY BE A BIT OVERDONE PRIOR TO LATE AFTERNOON/EARLY
EVENING DUE TO CLOUD COVER. HOWEVER...WITH VORTICITY AROUND THERE
COULD BE POP UP SHOWERS. MAY NEED TO MAKE SOME TWEAKS TO POPS AND
TEMPS BUT NO MAJOR SURGERY. MORE LATER.
&&
.PREVIOUS DISCUSSION ISSUED 245 AM...
TODAY AND MONDAY...
FORECASTS WILL BECOME A LITTLE TRICKY THESE DAYS AS SEVERAL PACIFIC
SHORTWAVES MOVE INTO THE REGION...OVER A WARM MOIST AIRMASS...AND
WITH A VERTICAL WIND SHEARED ENVIRONMENT MAINLY WESTERN AZ MONDAY.
AT 08Z A SMALL NEGATIVE TILT DIFLUENT TROF WAS SEEN MOVING ASHORE IN
CENTRAL AZ...AND FORECAST TO MOVE QUICKLY SOUTHEASTWARD INTO CENTRAL
AZ THIS MORNING AND AFTERNOON. ALSO AT 08Z...STARTING EARLY WERE A
FEW TSTMS ON RADAR NEAR BUCKEYE...GENERALLY IN FAR WEST PHOENIX WITH
TOPS TO 40 THSD FT. A CHANCE OF SHOWERS AND THUNDERSTORMS ARE
FORECAST ACROSS PARTS OF SOUTHWEST AND SOUTH CENTRAL ARIZONA THROUGH
THIS EVENING.
RECENT MODEL FORECASTS FOR MONDAY HAVE AMPLIFIED A SECOND MORE
ENERGETIC TROF TO MOVE INTO NORTHWEST AZ BY LATE AFTERNOON.
SIGNIFICANT DIFLUENT FLOW ALOFT IS FORECAST TO DEVELOP OVER PARTS OF
SOUTHWEST AND SOUTH CENTRAL AZ...GENERALLY NORTH OF A LINE FROM
PHOENIX TO BLYTHE CA. MODELS ARE CONSISTENT WITH FORECASTS OF
MODERATELY STRONG 850/700 20-30 KT SOUTHERLY WINDS AHEAD OF THE TROF
IN FAR WESTERN ARIZONA...WITH GOOD WIND VEERING PROFILES WITH HEIGHT
CHARACTERISTICALLY ASSOCIATED WITH ORGANIZED CONVECTION. THERE IS
ONE CAVEAT THOUGH. MODELS FORECAST A PLUME OF WARM MID LEVEL
TEMPERATURES TO MOVE INTO WEST CENTRAL AND SOUTHWEST AZ THAT COULD
STABILIZE THE AIRMASS. SPC IN THEIR CONVECTIVE OUTLOOK FOR DAY 2
(MONDAY)...HAVE NEARLY ALL OF AZ IN GENERAL TSTM POTENTIAL.
THEREFORE DUE TO THIS ENERGETIC TROF...AND CONCERNS ABOUT POTENTIAL
SHWR COVERAGE AND INTENSITY...WE WILL CONTINUE WITH A CHANCE OF
SHOWERS AND THUNDERSTORMS OVER PARTS OF SOUTHWEST AND SOUTH CENTRAL
AZ...INCLUDING PHOENIX.
TUESDAY...
NOT SURE ABOUT TUESDAY. VERY STRONG SOUTHWESTERLY FLOW ALOFT
ASSOCIATED WITH ANOTHER PACIFIC SHORTWAVE FORECAST TO MOVE ACROSS
FAR NORTHERN AZ COULD RESULT IN SHOWER POTENTIAL IN SOUTH CENTRAL.
CONFIDENCE IS LOW. THEREFORE WE WILL CONTINUE WITH A SLIGHT CHANCE
OF SHOWERS AND TSTMS GENERALLY FROM PHOENIX EASTWARD.
WEDNESDAY THROUGH SUNDAY...
ALTHOUGH STRONG UPPER LEVEL SOUTHWEST WINDS WILL CONTINUE...DUE TO
ADDITIONAL PACIFIC SHORTWAVES FLOWING WELL NORTH OF THE AREA...
MODELS INSIST THAT A STABLE AND WARM AIRMASS WILL PRECLUDE ANY SHWR
ACTIVITY. AFTN TEMPS THESE DAYS SHOULD BE NEAR NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
WILL SEE BETTER SHOT AT SOME SHOWERS AND THUNDERSTORMS
TODAY...MAINLY STARTING LATE IN THE AFTERNOON AND THROUGH THE
EVENING. COULD SEE A FEW STRONG STORMS INCLUDING GUSTY OUTFLOW WINDS
AND POTENTIALLY BLOWING DUST. HAVE MEDIUM CONFIDENCE IN TIMING FOR
VCTS IN TAFS...BUT COULD HAPPEN AN HOUR OR TWO EARLIER IF STORMS GET
GOING QUICKLY EARLY IN THE AFTERNOON. WIND DIRECTIONS AND SPEEDS WILL
BECOME PROBLEMATIC LATE THIS AFTERNOON AND EVENING DUE TO A DECENT
LIKELIHOOD OF SEVERAL OUTFLOWS AFFECTING THE PHOENIX AREA.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WILL SEE MID AND HIGH CLOUD DECKS PERSIST THROUGH MUCH OF THE DAY AND
A PREDOMINANT SOUTH TO WESTERLY DIRECTION. SOME OCCASIONAL GUSTINESS
WILL BE POSSIBLE THIS AFTERNOON AND EVENING...BUT GUSTS ARE EXPECTED
TO REMAIN LESS THAN 20KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
LINGERING MOISTURE WILL KEEP SLIGHT THUNDERSTORM CHANCES GOING
TUESDAY...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY. MOISTURE
WILL DECLINE WEDNESDAY ONWARD FOR REMOVAL OF STORM CHANCES. WITH
DRIER AIR...MINIMUM HUMIDITIES WILL DECLINE WITH MOST LOWER
ELEVATIONS DROPPING BELOW 20 PERCENT BY FRIDAY. OVERNIGHT RECOVERY
DECLINES AS WELL BUT REMAINS GOOD. TEMPERATURES WILL BE BELOW NORMAL
TUESDAY FOLLOWED BY A SLOW WARMING TREND. WINDS WILL TEND TO BE
LIGHT AND FAVOR SOUTHWEST AND WEST DIRECTIONS DURING THE AFTERNOONS
AND EVENINGS.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT ACCORDING TO STANDARD PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...KUHLMAN
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
426 AM PDT SUN SEP 13 2015
.SYNOPSIS...
COOLING THIS WEEKEND WITH A SLIGHT CHANCE OF AFTERNOON SHOWERS AND
THUNDERSTORMS OVER HIGHER TERRAIN. ADDITIONAL COOLING NEXT WEEK
WITH A CHANCE OF RAIN AT TIMES, MAINLY OVER THE MOUNTAINS.
&&
.DISCUSSION...
Scattered radar echoes early this morning over Sonoma, Napa,
Lake, Solano, Sacramento, San Joaquin, and Stanislaus counties.
It`s been difficult to verify if all echoes are resulting in
sprinkles, but there was an observation at the Santa Rosa Airport
of 0.01" light rain. Have added mention of sprinkles to the
forecast this morning for those counties (except Sonoma & Napa
which are not in our forecast area).
Cloud cover and any sprinkles are due to a weak low pressure
system straddling the Central/Northern CA coastline today coupled
with remnant moisture from former Hurricane Linda.
Instability associated with that low could also trigger a slight
chance of showers/thunderstorms over higher terrain of the Coastal
& Sierra ranges. Taking a look at the HRRR along with the NAM
CAPE and Modified Total Totals...it looks like the Sierra Crest
has a slightly better shot of development today than the Coastal
mountains.
The forecast highs for today will be a bit tricky. Clouds and
smoke (Butte & Valley wildfires) will impact how much solar
radiation reaches the surface similar to what happened yesterday
so expect highs today to be within a few degrees of yesterday.
Valley highs around mid 80s to mid 90s...Delta mid 70s to mid
80s...Mountains 70s to 80s.
For Monday into Wednesday a large synoptic trough pattern will
dominate over NorCal keeping temperatures cooler than normal with
increasing chances of rain. Tuesday and Wednesday will be the
coolest days this week with daytime highs as much as 10-20
degrees below normal in our CWA...we`re talking 70s in much of the
valley! Sprinkles and limited thunderstorm development possible on
Monday...rain on Tuesday over portions of NorCal...more
widespread chance of rain on Wednesday for much of our CWA.
JBB
&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)
Upper trough forecast to move through Pacific Northwest mid week
expected to be lifting to the northeast by early Thursday. ECMWF a
little slower with moving this trough out so kept chance pops in
for northern half of CWA. Precip chances move to the north
Thursday afternoon as upper trough continues eastward. GFS and
ECMWF have ridging building in my afternoon so most locations
should see some warming Thursday. Dry conditions expected for the
remainder of the extended period as flat ridging remains over the
west coast. A slow warming trend will bring daytime highs up back
above normal by next weekend.
&&
.AVIATION...
Mid level broken/overcast deck around 12-15kft expected to remain
over region through most of next 24 hours. Sustained winds
generally less than 15 knots TAF sites with gusts 25-30kts through
the delta. Generally VFR conditions next 24 hours except
occasional MVFR visibility due to smoke from wildfires.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
816 AM EDT SUN SEP 13 2015
.SYNOPSIS...
A WARM FRONT WILL APPROACH THE SOUTH COAST OF NEW ENGLAND
OVERNIGHT AS LOW PRESSURE MOVES ALONG IT. A SECOND LOW PRESSURE
SYSTEM WILL MOVE FROM THE MID ATLANTIC COAST TODAY...TO THE GULF
OF MAINE LATE TONIGHT. HIGH PRESSURE BUILDS ACROSS THE EASTERN
SEABOARD NEXT WEEK WITH AN EXTENDED PERIOD OF DRY WEATHER.
TEMPERATURES WILL WARM BY THE MIDDLE OF NEXT WEEK...WITH HIGHS
RUNNING AROUND 10 DEGREES ABOVE SEASONAL NORMALS INTO NEXT
WEEKEND. A COLD FRONT MAY APPROACH FROM THE NW SOMETIME NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
750 AM UPDATE...
NOTING SOME SCATTERED SHOWERS LINGERING ACROSS PORTIONS OF N MA AT
1130Z HEADING TO THE NE. NOT MUCH PRECIP SEEN ON 1145Z NE REGIONAL
RADAR MOSAIC. MAY SEE DECENT BREAK IN ORGANIZED PRECIP...BUT COULD
STILL SEE SOME WIDELY SCT SHOWERS THROUGH MIDDAY BRINGING ONLY
LIGHT PRECIP.
AFTER LOOKING AT 10Z HRRR MODEL AS WELL AS 06Z NAM...STILL SEEING
DEVELOPMENT OF MESO LOW PRES AROUND THE LOWER HUDSON VALLEY INTO W
CT/MA AROUND 18Z-20Z. THIS LOOKS TO BRING MORE LIFT AND LOW LEVEL
CONVERGENCE ALONG WITH WEAK ONSHORE FLOW /E-SE/ THAT MAY MEAN MORE
PRECIP DEVELOPING. DID CUT BACK ON PRECIP THROUGH MID MORNING...
THEN BLENDED TO BRING POPS BACK UP AROUND MIDDAY. ONCOMING SHIFT
WILL CONTINUE TO MONITOR.
REMAINDER OF NEAR TERM FORECAST WAS IN PRETTY GOOD SHAPE...BUT DID
UPDATE TO BRING CONDITIONS CURRENT AND INCORPORATED INTO NEAR TERM
TRENDS.
PREVIOUS DISCUSSION...
THE PARENT LOW PRESSURE OF THE COMPLEX SYSTEM NEAR OUR REGION
WILL REMAIN TO OUR WEST TODAY. EXPECTING SECONDARY LOW PRESSURE
TO DEVELOP AROUND LONG ISLAND INTO W CT...THEN WILL CROSS SOUTHERN
AREAS BY THIS EVENING. A POTENT MID LEVEL SHORTWAVE ALSO ARRIVES
THIS AFTERNOON. THE COMBINATION OF THE TWO WILL RESULT IN ANOTHER
PERIOD OF SHOWERS...MAINLY FROM MIDDAY INTO THIS EVENING.
INSTABILITY REMAINS POOR THROUGH THE DAY. CANNOT COMPLETELY RULE
OUT A FEW ISOLATED THUNDERSTORMS LATER TODAY...BUT IT WILL BE A
STRUGGLE TO GET THEM GOING.
NOT EXPECTING A LOT OF SUNSHINE TODAY...SO SEASONABLE TEMPERATURES
FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...
SECONDARY LOW PRESSURE MOVES FROM THE SOUTH COAST INTO THE GULF OF
MAINE TONIGHT. THIS WILL BRING AN END TO OUR SHOWERS FROM
SOUTHWEST TO NORTHEAST THIS EVENING. WINDS WILL TURN TO THE WEST
AND NORTHWEST AND BECOME GUSTY TOWARD DAYBREAK MONDAY.
MONDAY...
AN ANOMALOUS MID LEVEL TROUGH MOVES ACROSS NORTHERN NEW ENGLAND.
DEEP LAYER MOISTURE/CONVEYOR BELT IS WELL OFFSHORE. HOWEVER...WITH
SUCH A STRONG COLD POOL ALOFT...EXPECTING PLENTY OF DIURNAL
CLOUDS. THE RISK FOR SHOWERS WILL BE A TRICKIER DETERMINATION.
WITH ONLY THE MOISTURE ACCOMPANYING THE COLD POOL AVAILABLE...ANY
SHOWERS SHOULD BE FEW AND FAR BETWEEN. WOULD EXPECT MORE SHOWERS
IF THE CORE OF THIS COLD POOL PASSED CLOSER TO OUR REGION. THE
ABUNDANT CLOUDS AND COLDER AIR TO START...WILL MEAN SLIGHTLY LOWER
MAX TEMPERATURES. A GUSTY WEST WIND WILL BRING AN EARLY AUTUMN
FEEL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* DRY WEATHER EXPECTED MUCH IF NOT ALL OF NEXT WEEK
* EXPECT TEMPERATURES TO RUN MUCH WARMER THAN NORMAL BY MID WEEK
INTO NEXT WEEKEND
* A COLD FRONT MAY START TO APPROACH OUT OF SOUTHERN QUEBEC NEXT
WEEKEND
OVERVIEW...
MODELS AND ENSEMBLES CONTINUE TO SHOW A STRONG SIGNAL OF BUILDING
RIDGE AT THE SURFACE AND ALOFT ACROSS THE CENTRAL AND EASTERN
U.S. THROUGH MOST IF NOT ALL OF THIS LONG RANGE PERIOD. THIS MEANS
A RETURN TO DRY CONDITIONS AND WARM TEMPERATURES INTO NEXT WEEK.
EXPECT TEMPS TO RUN WELL ABOVE SEASONAL NORMALS THROUGH AT LEAST
FRIDAY...POSSIBLY INTO NEXT WEEKEND.
SOME MODEL SPREAD INTO NEXT WEEKEND...WITH POSSIBILITY OF RIDGE
FLATTENING IN THE NORTHERN STREAM WHILE A COLD FRONT AND MID
LEVEL SHORT WAVE TRIES TO SINK INTO NEW ENGLAND. QUESTIONABLE
TIMING OF THIS FEATURE THIS FAR OUT...BUT SOMETHING TO MONITOR.
USED A BLEND OF AVAILABLE GUIDANCE THROUGH MOST OF THIS
PERIOD...BUT DID LEAN MORE TOWARD ENSEMBLES FOR THE SATURDAY
TIMEFRAME DUE TO TIMING DIFFERENCES WITH THE POSSIBLE APPROACH OF
THE FRONT IF IT MAKES IT THAT FAR S WITH THE STRONG RIDGE IN
PLACE.
MONDAY NIGHT-TUESDAY...
H5 TROUGH EXITS THE REGION EARLY MON NIGHT...SO EXPECT SKIES TO
BECOME MOSTLY CLEAR TO CLEAR OVERNIGHT. W-NW WINDS WILL BE IN
PLACE SO EXPECT TEMPS TO FALL BACK THROUGH THE 50S. A FEW SPOTS
MAY DROP TO THE UPPER 40S IN THE FAR INLAND VALLEYS...WHILE
HOLDING AT AROUND 60 ALONG THE IMMEDIATE COAST. MAY SEE TYPICAL
LATE NIGHT PATCHY FOG DEVELOP ACROSS THE INLAND VALLEY LOCATIONS.
ON TUESDAY...HIGH PRES BUILDS E OUT OF THE APPALACHIANS AND MID
ATLC STATES. W-NW FLOW REMAINS IN PLACE WITH DEWPTS MAINLY IN THE
LOWER- MID 50S...SO WILL BE COMFORTABLE ACROSS THE REGION. NOTING
LOW LEVEL MIXING UP TO 900 HPA THOUGH WIND SPEEDS ONLY RUNNING AT
10-15 KT. EXPECTING TEMPS TO RISE TO THE MID 70S WELL INLAND AND
ACROSS HIGHER TERRAIN TO THE LOWER 80S AT MANY INLAND LOCATIONS.
WEDNESDAY THROUGH FRIDAY...
SURFACE HIGH PRES SETTLES ACROSS THE EASTERN SEABOARD ON
WEDNESDAY...THEN SLOWLY DRIFTS S THROUGH THE END OF THE WORK
WEEK. LIGHT NORTHERLY WINDS ON WED WILL SHIFT TO S-SW THU AND FRI.
NOTING H925 WARM TEMP AXIS SURGING INTO THE REGION...WITH READINGS
UP TO +20C TO +22C BOTH THU AND FRI. DEWPTS WILL SLOWLY RISE TO
THE LOWER- MID 60S DURING THIS TIMEFRAME...SO WILL BECOME A BIT
STICKY OUT OF DOORS. TEMPS WILL TOP OFF IN THE LOWER-MID 80S AWAY
FROM THE S COAST EACH DAY...BUT HOLDING IN THE MID-UPPER 70S ALONG
THE IMMEDIATE S COAST.
MAY SEE PATCHY FOG DEVELOP EACH LATE NIGHT/EARLY MORNING TIMEFRAME
IN THE NORMALLY PRONE INLAND VALLEYS AS WELL AS ALONG THE S COAST.
SATURDAY...
QUESTIONS ABOUND WITH TIMING AND TRACK OF H5 SHORT WAVE IN THE
NORTHERN STREAM FLOW AND HOW FAR S THIS WILL PUSH...ALONG WITH
ITS ASSOCIATED SURFACE COLD FRONT. WITH SUCH A STRONG SURFACE AND
UPPER RIDGE IN PLACE...MAY BE TOUGH TO MOVE INTO THE REGION
DURING SATURDAY. EXPECT ANOTHER WARM DAY WITH SW WINDS IN PLACE.
HAVE MENTIONED SLIGHT CHANCE POPS INTO N CENTRAL AND WESTERN
AREAS DURING SAT AFTERNOON...BUT RATHER LOW CONFIDENCE DUE TO
MODEL VARIANCE.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH MONDAY/...
TODAY AND TONIGHT...HIGH CONFIDENCE ON TRENDS...LOWER CONFIDENCE
ON TIMING.
AREAS OF IFR-LIFR CIGS BUT MAINLY VFR VSBYS. CIGS SHOULD IMPROVE
TO VFR ALONG S COAST BY MID TO LATE THIS MORNING...MOVING INLAND
DURING THE AFTERNOON. MVFR-IFR CIGS MAY LINGER ACROSS NE AND N
CENTRAL MA INTO THIS EVENING.
REDEVELOPMENT OF SHOWERS LIKELY THIS AFTERNOON CONTINUING INTO
TONIGHT...THEN ENDING AROUND MIDNIGHT MONDAY. AN ISOLATED
THUNDERSTORM CANNOT BE RULED OUT THIS AFTERNOON. MAY SEE PATCHY
MVFR CIGS/VSBYS IN ANY HEAVIER SHOWERS.
EXTREMELY STRONG WINDS FROM THE SOUTH WILL BE BLOWING IN THE MID
AND UPPER LEVELS OF THE ATMOSPHERE...RANGING FROM 65 KT AT 18000
FT TO 110 KT AT 30000 FT. HOWEVER...THIS INCREASE SHOULD BE
GRADUAL ENOUGH AT LOW LEVELS TO PRECLUDE LOW LEVEL WIND SHEAR. BUT
PILOTS SHOULD BE VERY AWARE OF THESE SPEEDS.
MONDAY...HIGH CONFIDENCE. VFR WITH MARGINAL MVFR-VFR CIGS POSSIBLE
HIGHER TERRAIN IN SPOT SHOWER. GUSTY WEST WINDS UP TO 25 KT.
KBOS TERMINAL...OVERALL MODERATE CONFIDENCE DUE TO TIMING ISSUES
WITH LOWER CIGS.
KBDL TERMINAL...OVERALL MODERATE CONFIDENCE DUE TO TIMING ISSUES
OF LOWER CIGS.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE.
EXPECT MAINLY VFR CONDITIONS. MAY SEE LOCAL MVFR-IFR VSBYS IN
PATCHY LATE NIGHT FOG ACROSS NORMALLY PRONE AREAS ACROSS THE CT
VALLEY AND E SLOPES OF THE BERKSHIRES. W WINDS GUSTING TO 20 KT
EARLY ALONG E COAST THEN DIMINISHING.
TUESDAY THROUGH THURSDAY...HIGH CONFIDENCE.
VFR. MAY SEE BRIEF MVFR-IFR VSBYS IN PATCHY FOG LATE TUE AND WED
NIGHTS ACROSS PRONE INLAND LOCATIONS...WHICH SHOULD IMPROVE BY
AROUND 12Z-13Z.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH MONDAY/...HIGH CONFIDENCE.
SHOWERS END ACROSS THE WATERS THIS MORNING...BUT SHOULD RETURN
THIS AFTERNOON AND EVENING. WINDS SHOULD WEAKEN AS A LOW PRESSURE
PASSES TO THE EAST OF THE WATERS LATER THIS MORNING...WITH
NORTHEAST WINDS NORTH OF NANTUCKET AND THE VINEYARD AND SOUTHWEST
WINDS SOUTH OF THE ISLANDS. ANOTHER LOW PRESSURE WILL MOVE ACROSS
SOUTHEAST MA THIS EVENING. BEHIND THIS LOW PRESSURE...WINDS MAY
AGAIN INCREASE TO SMALL CRAFT ADVISORY THRESHOLDS FROM THE WEST
TOWARD DAYBREAK MONDAY. SEAS ARE FORECAST TO BUILD UP TO 5 TO 7 FT
OVER THE COASTAL WATERS SOUTH OF NEW ENGLAND LATE TONIGHT. WEST
WINDS 20 TO 25 KT WITH DRY WEATHER AND GOOD VSBY FOR MONDAY.
SMALL CRAFT ADVISORIES WILL CONTINUE FOR AT LEAST A PORTION OF
THE WATERS INTO MONDAY. DESPITE A BRIEF PERIOD OF MORE TRANQUIL
CONDITIONS ACROSS THE SOUTHERN OUTER COASTAL WATERS THIS
MORNING...THOUGHT IT WOULD BE LESS CONFUSING TO CONTINUE THE SMALL
CRAFT ADVISORY FOR THESE WATERS...AS ROUGH SEAS AND GUSTY WINDS
RETURN THIS EVENING AND TONIGHT.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT...HIGH CONFIDENCE.
EXPECT W WINDS GUSTING TO 25 KT ON THE OUTER WATERS MONDAY
EVENING...THEN DIMINISHING. SEAS WILL LINGER AROUND 5-7 FT
EARLY...THEN WILL SLOWLY SUBSIDE BUT MAY REMAIN AROUND 5 FT ON
THE FAR OUTER WATERS THROUGH THE NIGHT.
TUESDAY THROUGH THURSDAY...HIGH CONFIDENCE.
EXPECT WINDS AND SEAS REMAINING BELOW SMALL CRAFT CRITERIA. MAY
SEE SW WIND GUSTS UP TO 20 KT DURING LATE THU/THU NIGHT ON THE
EASTERN WATERS. SEAS TO AROUND 5 FT MAY LINGER EARLY TUESDAY ON
THE OUTER WATERS...THEN WILL SUBSIDE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 6 PM EDT MONDAY FOR
ANZ232>234.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM EDT
MONDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT MONDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...BELK/EVT
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...BELK/EVT
MARINE...BELK/EVT
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1111 PM CDT SAT SEP 12 2015
.UPDATE...
ISSUED AT 835 PM CDT SAT SEP 12 2015
The rather deep upper trof that produced the scattered showers and
isolated storms this afternoon across east central and southeast
IL has shifted east of the forecast area early this evening. High
pressure to our northwest will track slowly across the area over
the next 12 hours bringing clear and calm conditions for the
overnight hours along with chilly early morning lows. Temperatures
early this evening have already dropped to near 50 at Galesburg
with most of the remainder of the area in the middle 50s this
hour.
Had to make some minor tweaks to the temperature trends this eve
due to the rapid temp fall over the past couple of hours with a
few downward adjustments to the early morning lows as well. Surface
ridge axis by morning forecast to be over extreme western IL before
shifting off to our east by afternoon, allowing winds to gradually
become southwest signaling the onset of a warming trend that
should last well into the new work week. Updated ZFP will be out
by 900 pm.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 239 PM CDT SAT SEP 12 2015
Vorticity maximum centered between Springfield and Decatur this
afternoon per water vapor imagery, within the deep upper trough that
covers much of the Midwest. RAP guidance shows a cold pocket of 500
mb temps near -24C just south of this, which has helped feed the
scattered showers that have formed over east central and southeast
Illinois. Drier air in the lower levels have resulted in a bit of
small hail accompanying the heavier showers. Other showers near
Champaign have been tracking south-southwest off Lake Michigan with
more behind them, although wind trajectories are starting to turn
more northerly and the lake feed should shift more to along the
Indiana border. The diurnal cloudiness is fading some across the far
northern CWA, and should rapidly dissipate over the forecast area by
sunset, with mostly clear conditions prevailing overnight. Still
looks to be a cool night, with temperatures falling into the mid
40s.
.LONG TERM...(Sunday THROUGH Saturday)
ISSUED AT 239 PM CDT SAT SEP 12 2015
Morning upper air and moisture channel data depicts deep upper level
over Great Lakes into sotheast MO. Series of weak vort maxes/lobes
in the mid MS river valley rotating through the bottom of the trof,
with main max near Quad Cities moving SSE. With ample low level
moisture, and cold air aloft, scattered showers over the eastern
portions of cwa today, lingering into evening.
Models drift the upper trof to the east into Sunday, allowing
warming low and mid level flow to begin to work into state. Upper
ridge begins to build toward area and slow warming trend into
midweek.
In the extended period, models have agreed a bit more on slowing of
the approaching next frontal system. System approaches now Friday,
with pops delayed into Thursday night, with better chances for rain
Friday and Friday night with front, on the latest run. A bit cooler
with the increased cloud cover with front. Exact details on frontal
passage still somewhat hazy.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Sunday NIGHT)
ISSUED AT 1108 PM CDT SAT SEP 12 2015
VFR conditions will continue thru this forecast period. High
pressure will slowly drift across the area Sunday morning
bringing a clear sky and light winds to the region before
moving off to our east by afternoon. As the ridge axis shifts
across the area Sunday, we may see some cirrus push across the
area but that is about it cloud-wise. Light and variable winds
tonight will gradually shift into the southwest during the
afternoon with speeds of 10 kts or less.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Goetsch
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
650 AM EDT SUN SEP 13 2015
.SYNOPSIS...
ISSUED AT 333 AM EDT SUN SEP 13 2015
AN UNSEASONABLY COOL AIRMASS OVER GREAT LAKES REGION COMBINED
WITH NORTHWEST WINDS MAY RESULT IN A FEW LIGHT LAKE EFFECT SHOWERS
OVER NORTHWEST INDIANA AND SOUTHWEST MICHIGAN THIS MORNING...
OTHERWISE FAIR WEATHER IS EXPECTED TODAY AND TONIGHT AS RIDGE OF
HIGH PRESSURE MOVES EAST ACROSS THE MIDWEST. HIGHS TODAY WILL BE
IN THE MID TO UPPER 60S. WITH LOWS TONIGHT IN THE MID TO UPPER
40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM EDT SUN SEP 13 2015
IR IMAGERY INDICATES A LAKE EFFECT CLOUD BAND EXTENDED FROM
CENTRAL LAKE MICHIGAN INTO NW INDIANA EARLY THIS MORNING. LOT 88D
DETECTING VERY WEAK REFLECTIVITY WITH THIS FEATURE AS IT SHIFTS
SLOWLY EAST. MAINTAINED A SLIGHT CHC OF RW- ACROSS OUR FAR NW
ZONES THIS MORNING AS LOW LEVEL FLOW CONTS TO SLOWLY BACK TO
NW. OTRWS HIGH PRESSURE RIDGE MOVG ACROSS THE AREA WILL PROVIDE
FAIR WX IN OUR AREA DURING THE SHORT TERM PERIOD. AIR ALOFT
REMAINS COLD ENOUGH FOR SOME LOW LEVEL INSTABILITY TODAY SO
CONSIDERABLE CU SHOULD DEVELOP THIS MORNING AND CONT THROUGH THE
AFTN BEFORE DISSIPATING WITH LOSS OF HEATING THIS EVE. THIS SHOULD
LIMIT DIURNAL HEATING SOMEWHAT... EXPECT HIGHS ONLY IN THE M-U60S.
RIDGE AXIS WILL MOVE EAST OF THE AREA TONIGHT ALLOWING FOR
AN INCREASING SWLY GRADIENT BUT THERE STILL SHOULD BE AT LEAST A
PERIOD OF DECOUPLING AND RATHER STRONG RADIATIONAL COOLING OVER
MOST OF THE AREA. MOSGUIDE SEEMED TO CAPTURE THIS WELL WITH LOWS
FCST IN THE M40S OVER MOST OF THE AREA... EXCEPT U40S/L50S FAR NW
WHERE SWLY GRADIENT WINDS WILL DVLP FIRST AND BE STRONGEST
OVERNIGHT ALONG WITH SOME LAKE WARMING INFLUENCE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM EDT SUN SEP 13 2015
THE CHALLENGES THIS PERIOD INCLUDE THE TIMING OF SHORT WAVE TROFS
AND ASSOCIATED WEATHER LATE THIS WEEK. THE GFS...GFS ENSEMBLES...
ECMWF AND CANADIAN GEM/ENSEMBLES SHOW A LARGE DIVERGENCE OF
SOLUTIONS HANDLING THE UPPER LEVEL SYSTEMS MOVING THROUGH THE LARGE
SCALE PATTERN. THERE WAS ESSENTIALLY A SPLIT AMONG SOLUTIONS WITH
THE GFS AND MANY ENSEMBLE MEMBERS FAVORING A FASTER SOLUTION
BRINGING THE FRONT THROUGH BY FRIDAY FOLLOWED BY CLEARING SATURDAY.
ON THE CONTRARY...THE ECMWF AND CANADIAN GEM AND SOME GEM ENSEMBLES
ALSO FAVOR A SLOWER SOLUTION WHICH MEANS FRIDAY WOULD BE VERY WARM
AND DRY WITH THE FRONT AND STORMS HOLDING OFF UNTIL FRIDAY NIGHT OR
SATURDAY. GIVEN THIS VARIETY OF SOLUTIONS...HAVE KEPT A CHANCE FOR
SHOWERS THURSDAY NIGHT THROUGH SATURDAY. FOR NOW...KEPT FRIDAY WARM
WITH HIGHS IN THE 80S...BUT THERE IS MUCH UNCERTAINTY WHEN THE FRONT
WILL PASS THROUGH THE AREA. OTHERWISE...TEMPERATURES WILL RECOVER
RAPIDLY EARLY THIS WEEK AS RETURN FLOW INCREASES ON THE WEST SIDE OF
A LARGE HIGH PRESSURE AREA. TEMPERATURES WILL BE ABOVE NORMAL
WEDNESDAY...THURSDAY...AND POSSIBLY FRIDAY UNTIL THE FRONT PASSES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 648 AM EDT SUN SEP 13 2015
SHORE PARALLEL LAKE EFFECT CLOUD BAND MOVG SLOWLY E-SE
SHOULD MOVE ACROSS NRN INDIANA THIS MORNING. ONLY VERY WEAK ECHOES
CONT TO BE PICKED UP BY 88D WITHIN THE PLUME. 06Z NAM AND LATEST
RAP13 INDICATE NO -SHRA WILL OCCUR WITH THE CLOUD BAND THOUGH
LATEST HRRR STILL HAS SOME LIGHT QPF OVER NRN INDIANA THIS
MORNING. KEPT TAFS DRY WITH A VFR CIG THIS MORNING DUE TO CLOUD
PLUME MOVG ONSHORE AND DIURNAL CU DEVELOPMENT. RIDGE WILL PASS
THIS EVE ALLOWING WINDS TO BACK TO SWLY WITH GENERALLY CLEAR SKIES
TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1127 PM CDT SAT SEP 12 2015
.UPDATE...
ISSUED AT 1127 PM CDT SAT SEP 12 2015
Some isolated showers have developed across central KS due to
isentropic lift. The RAP seems to be handling this the best so
have inserted some small pops for isolated showers through mid
morning.
&&
.SHORT TERM...(THIS EVENING THROUGH Sunday)
ISSUED AT 256 PM CDT SAT SEP 12 2015
Northwest flow persisted in the upper levels today while surface
high pressure was centered nearly directly overhead. The surface
high will slowly shift east overnight with southerly return flow
pattern, already in place in central KS, will intensify slightly and
shift east through tonight. A narrow band of moisture and isentropic
ascent that developed on the eastern fringe of the return flow this
morning is expected to develop in similar fashion again overnight
tonight. While the morning lift was able to produce light rain
showers and sprinkles, the moist layer to be lifted tonight is not
particularly deep and has only a few J/kg of elevated CAPE...so
think that showers should struggle a bit more tonight. Virtually all
model guidance agrees with this as well, keeping any very light
shower activity south of the forecast area. Did keep overnight lows
a bit warmer though as there should be a fair amount of mid level
cloud cover. Clouds are likely to dissipate by tomorrow afternoon,
and some warm advection should lead to temperatures in the middle
70s east to lower 80s in central KS.
.LONG TERM...(Sunday NIGHT THROUGH Saturday)
ISSUED AT 256 PM CDT SAT SEP 12 2015
On Sunday night the mid-level pattern will begin to transition to
southwest flow aloft with several weak embedded shortwave troughs.
Each wave will bring a slight for showers and storms due to the
associated lift. Also, isentropic lift across the area should
support isolated to scattered precip Monday morning and possibly
lasting through the afternoon hours. Both Monday and Tuesday night
the isentropic lift increases and weak shortwaves track close to the
area therefore bringing precip chances yet again. The highs will
climb into the mid to upper 80s with a few low 90s on Tuesday and
Wednesday. Later in the week a series of shortwaves progress over
the northern plains and upper Midwest, which will drag a cold front
towards the area. Depending on the timing of the front Thursday
could warm into the upper 80s to low 90s. The GFS is faster with the
frontal arrival during the day Thursday, while the ECMWF hold off
until the overnight. Not too confident in the precip chances
associated with the front due to timing issues and possible
mesoscale features. Behind the front will bring cooler temperatures
as the front reaches southern KS and northern OK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Sunday NIGHT)
ISSUED AT 1127 PM CDT SAT SEP 12 2015
Coverage in shower activity is expected to remain isolated and
mainly southwest of the terminals. There could still be some light
rain, especially in MHK but its impact should be minimal as
conditions remain VFR. If a stronger shower moves in, there could
be some brief MVFR VSBY, but trying to time this is almost
impossible so will keep monitoring trends and amend if necessary.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Barjenbruch
LONG TERM...Sanders
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
325 PM EDT SUN SEP 13 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 324 PM EDT SUN SEP 13 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP TROF EXTENDING FROM
THE EASTERN GREAT LAKES S TO THE GULF COAST. MID LEVEL RIDGE FROM
THE NRN PLAINS TO NRN ONTARIO IS SUPPORTING SFC HIGH PRES RIDGE
EXTENDING FROM TX NE ACROSS ERN UPPER MI. ASSOCIATED DRY AIR
MASS...ONLY SCT MID-HIGH CLOUDS AND WAA IN SW FLOW HAVE ALLOWED
TEMPS TO REBOUND BACK INTO THE UPPER 60S TO MID 70S ACROSS MUCH OF
THE FCST AREA THIS AFTERNOON.
COMPARED TO LAST NIGHT TONIGHT WILL BE MUCH WARMER. UNDER CLEAR
SKIES...MIN TEMPS WILL BE MOSTLY IN THE 50S...WARMEST IN THE
DOWNSLOPE AREAS NEAR LAKE SUPERIOR. THE USUAL INTERIOR COLD SPOTS
WILL SLIP INTO THE UPPER 40S.
ALL 12Z MODELS INDICATE DRY CONDITIONS MONDAY UNDER RISING 5H RIDGE
HEIGHTS WITH THE EXCEPTION OF THE GFS. THE GFS GENERATES PCPN OVER
THE WRN THIRD OF THE CWA FROM SHEARED OUT SHORTWAVE RIPPLING THRU
THE MID-UPR RIDGE AND ALONG/AHEAD OF ASSOC SFC TROUGH. LOOKING AT
THE GFS BUFR SNDGS AT KIWD IT/S HARD TO IMAGINE ANY PCPN BEING
SQUEEZED OUT OF SO DRY A SOUNDING PROFILE. ALSO...ALL THE POSITIVE
AREA (370 J/KG CAPE) IS ABOVE 650 MB AND THERE IS A 14C CAP AT 775
MB WITH OVER 250 J/KG CIN TO OVERCOME. WILL GO WITH CONSENSUS AT
THIS POINT AND KEEP A DRY FCST ACROSS THE CWA.
WITH 16 TO 19C 8H TEMPS...EXPECT HIGH TEMPS REACHING NEAR 80F ACROSS
MUCH OF THE WRN HALF THE CWA WITH MID 80S POSSIBLE NEAR LAKE SUPERIOR
IN DOWNSLOPING SW FLOW GUSTING AT OR ABOVE 20 KT. INLAND TEMPS WILL
BE A FEW DEGREES COOLER (MID 70S) WITH SOME MODERATION IN SW OFF LAKE
MICHIGAN. TEMPS NEAR THE LAKE MICHIGAN SHORELINE WILL ONLY BE AROUND
70F.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 257 PM EDT SUN SEP 13 2015
LATE SUMMER WARMTH IN STORE FOR THE UPCOMING WEEK. COOLER WEATHER
RETURNS BY NEXT WEEKEND. BEST CHANCES OF RAIN OCCUR THU-FRI AS COLD
FRONT WORKS ACROSS UPPER GREAT LAKES REGION.
AHEAD OF THE MAIN RAIN CHANCES LATER IN THE WEEK...THERE ARE STILL
HINTS OF WEAK SHORTWAVES MOVING THROUGH IN AN INCREASINGLY AMPLIFIED
SW UPPER FLOW ALOFT. UPPER WAVES ARE LACKING FOR MOISTURE THOUGH.
SOUNDINGS INDICATE THERE MAY BE INTERVALS OF MID CLOUDS 15-20 KFT
BUT IT STAYS VERY DRY BLO THAT CLOUD BASE. SINCE THE SOUNDINGS SHOW
LIFT IN THE MOIST LAYER WITH SOMEWHAT STEEPER LAPSE RATES...SUPPOSE
THERE COULD BE THICKER MID CLOUDS AND SOME SPRINKLES AT TIMES. BEST
CHANCE OF SHRA OR TSRA WOULD BE TUE NIGHT INTO WED MORNING OVER THE
WEST ESPECIALLY AS H85 JET VEERS SW AND BECOMES AIMED AT UPPER LAKES
WITH STRONGER MOISTURE ADVECTION. H85 JET AND CONVERGENCE WOULD
INTERACT WITH INSTABILITY ALOFT TO TRIGGER THE SHRA/TSRA.
ADDITIONALLY...MOST MODELS INDICATE H7-H5 Q-VECTOR CONVERGENCE
MOVING THROUGH WITH A STRONGER SHORTWAVE...AT LEAST COMPARED TO THE
WEAKER WAVES ON MON AND TUE. OVERALL...SEEMS THERE IS ENOUGH
EVIDENCE TO KEEP SMALL POPS IN FOR TUE NIGHT AND WED OVER THE WEST
AND FARTHER TO THE EAST ALONG LK SUPERIOR AND OVER LK SUPERIOR.
LATER ON WED...SFC BASED INSTABILITY SHRA/TSRA CHANCES LOOK SLIM AS
WITH SLOWER FRONTAL MOVEMENT TO THE EAST...GREATEST MLCAPES TOWARD
1000J/KG REMAIN OVER NEB/IA INTO MN.
LATE SUMMERTIME WARMTH PROBABLY ENDS UP BEING THE MAIN STORY FOR
MOST OF THE WEEK. NOT UNCOMMON TO SEE READINGS INTO THE 80S IN MID
SEPTEMBER AS RECORDS FOR 14-16 SEPT ARE STILL IN THE UPR 80S TO MID
90S FOR MANY LOCATIONS. FOR THIS WEEK...BASED ON H85 TEMPS OF AT
LEAST 16 ON TUE AND 18-20C WED AND THU...SHOULD SEE READINGS WELL
INTO THE 80S WITH EVEN A FEW LOW 90S POSSIBLE. NEED DEEPER MIXING TO
SEE THAT DEGREE OF WARMTH THOUGH AND ANY SIGNIFICANT MID CLOUDS WILL
DAMPEN THAT POTENTIAL. EVEN SO THOUGH...STEADY AND GUSTY AT TIMES S
TO SW WINDS IN TIGHER PRESSURE GRADIENT BTWN TROUGH OVER PLAINS AND
RIDGE OVER EASTERN CONUS RESULTS IN MINIMAL LAKE MODIFICATION AWAY
FM LK MICHIGAN SHORE AND WILL ALLOW DOWNSLOPE AREAS NEAR LK SUPERIOR
FM WEST ACROSS KEWEENAW TO NORTH CENTRAL TO SEE WARMEST TEMPS. EVEN
WITH THE WARMER TEMPS...HUMIDITY SHOULD REMAIN IN CHECK WITH DWPNTS
MOSTLY IN THE 50S. MOST HUMID DAY WOULD BE ON THU WITH DWPNTS INTO
THE 60S JUST AHEAD OF THE FRONT.
CONCERNING THE MAIN RAIN CHANCES THIS WEEK...MODELS STILL DIFFER ON
TIMING OF FROPA THU/FRI BUT THAT IS PRETTY TYPICAL FOR BEING THAT
FAR OUT. GFS IS QUICKER THAN ECMWF...WHICH IS ALSO A USUAL BIAS.
GIVEN THE UPPER LEVEL FLOW PATTERN EVEN ON THE GFS WITH BROAD TROUGH
OVER WESTERN CONUS AND RIDGE OVER THE EASTERN CONUS...GOING TO FAVOR
THE SLOWER ECMWF WITH ITS FROPA OCCURRING THU NIGHT INTO FRI. ALSO
SINCE UPPER TROUGH IS JUST DIGGING INTO THE UPPER LAKES ON FRIDAY
WITH FRONT STILL CLOSE BY...LIKE THE ECMWF STALLING THE FRONT OUT
AND ALLOWING FOR BETTER CHANCES OF RAIN ON FRIDAY. WILL TREND THAT
WAY FOR THIS FORECAST. THIS IDEA WHICH IS ALSO SUPPORTED BY THE GEM-
NH IS A NOTEABLE SLOWER TREND AS 24 HR AGO BOTH OF THESE MODELS
SHOWED FRONT/QPF MAINLY EAST OF CWA FOR FRIDAY. MUCAPES 0-3KM 1000-
2000J/KG AND SW LOW-LEVEL JET INTO THE UPPER GREAT LAKES SUPPORTS
TSRA TOO. SHEAR IS STRONGEST THU NIGHT OVERNIGHT INTO FRI WHICH IS
PROBABLY WHEN STRONG TO SEVERE STORMS COULD OCCUR SOMEWHERE OVER THE
REGION. PWATS OVER 1.50 INCHES WOULD ALSO SUPPORT HEAVY RAIN.
LATEST GEM-NH SUGGESTS LINGERING SHRA ON SATURDAY...BUT EVEN
EXTRAPOLATION OF THAT SOLN POINTS TO MOST OF THE DAY BEING DRY. KEPT
WITH CONSENSUS BUT REMOVED POPS IN THE AFTN. REST OF WEEKEND LOOKS
DRY BUT COOLER AS HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT.
TEMPS MAINLY WILL BE IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 131 PM EDT SUN SEP 13 2015
UNDER DRY AIR MASS...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW
THRU THIS FCST PERIOD. INCREASING PRES GRADIENT WILL LEAD TO GUSTY
SW WINDS TO 15-20KT THIS AFTN AND DURING THE DAY ON MON...AND DEVELOPING
NOCTURNAL INVERSION THIS EVENING WILL LEAD TO LLWS AT ALL TERMINALS
TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 324 PM EDT SUN SEP 13 2015
IN GENERAL...FAIRLY WINDY CONDITIONS ARE SHAPING UP FOR LAKE
SUPERIOR THRU THE MIDWEEK PERIOD AS PATTERN FOR THE NEXT SEVERAL
DAYS WILL FEATURE HIGH PRES OFF TO THE SE AND E WITH A LOW PRES TROF
TO THE W/NW. EXPECT PERIODS OF 15-25KT AND EVEN 20-30 KT S TO SW
WINDS. ONE PERIOD OF STRONGER WINDS WILL OCCUR TONIGHT INTO MONDAY
MORNING WITH THE STRONGEST WINDS OVER WESTERN LAKE SUPERIOR. THE
NEXT PERIOD OF STRONGER WINDS WILL OCCUR LATE TUE THRU WED WITH THE
STRONGEST WINDS THIS TIME OVER EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
259 PM EDT SUN SEP 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 426 AM EDT SUN SEP 13 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF EXTENDING FROM THE
CNTRL GREAT LAKES S TO THE GULF COAST. TROF IS IMPRESSIVELY DEEP
OVER THE TENNESSEE VALLEY WHERE 500MB HEIGHT ANOMALIES ARE AT 5
STANDARD DEVIATIONS BLO THE LONG TERM MID SEPT AVG. MID LEVEL RIDGE
FROM THE NRN PLAINS TO NRN ONTARIO IS SUPPORTING SFC HIGH PRES RIDGE
EXTENDING FROM TX NE ACROSS ERN UPPER MI. ASSOCIATED DRY AIR
MASS/CLEAR SKIES/CALM WIND HAS ALLOWED TEMPS TO FALL DOWN INTO THE
30S OVER MUCH OF THE FCST AREA. TRADITIONAL COLD SPOTS HAVE FALLEN
TO AROUND FREEZING.
WITH DRY AIR DOMINATING THE SHORT TERM...NOT A WHOLE LOT TO TALK
ABOUT THIS MORNING. DEVELOPING SW FLOW BTWN DEPARTING HIGH PRES
RIDGE AND LOW PRES TROF MOVING ACROSS SCNTRL CANADA WILL RAISE 850MB
TEMPS FROM 4C E AND 8C W AT 12Z TO 9C E AND 12C W BY EVENING. THIS
WAA/ISENTROPIC ASCENT SHOULD YIELD A BAND OF SCT-BKN MID/HIGH CLOUDS
THAT WILL SPREAD WNW TO ESE ACROSS THE AREA TODAY. EXPECT MAX TEMPS
TO REBOUND INTO THE UPPER 60S TO MID 70S.
COMPARED TO CURRENT CONDITIONS EARLY THIS MORNING...TONIGHT WILL BE
MUCH WARMER. UNDER CLEAR SKIES...MIN TEMPS WILL BE MOSTLY IN THE
50S...WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. THE USUAL
INTERIOR COLD SPOTS WILL SLIP INTO THE UPPER 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 257 PM EDT SUN SEP 13 2015
LATE SUMMER WARMTH IN STORE FOR THE UPCOMING WEEK. COOLER WEATHER
RETURNS BY NEXT WEEKEND. BEST CHANCES OF RAIN OCCUR THU-FRI AS COLD
FRONT WORKS ACROSS UPPER GREAT LAKES REGION.
AHEAD OF THE MAIN RAIN CHANCES LATER IN THE WEEK...THERE ARE STILL
HINTS OF WEAK SHORTWAVES MOVING THROUGH IN AN INCREASINGLY AMPLIFIED
SW UPPER FLOW ALOFT. UPPER WAVES ARE LACKING FOR MOISTURE THOUGH.
SOUNDINGS INDICATE THERE MAY BE INTERVALS OF MID CLOUDS 15-20 KFT
BUT IT STAYS VERY DRY BLO THAT CLOUD BASE. SINCE THE SOUNDINGS SHOW
LIFT IN THE MOIST LAYER WITH SOMEWHAT STEEPER LAPSE RATES...SUPPOSE
THERE COULD BE THICKER MID CLOUDS AND SOME SPRINKLES AT TIMES. BEST
CHANCE OF SHRA OR TSRA WOULD BE TUE NIGHT INTO WED MORNING OVER THE
WEST ESPECIALLY AS H85 JET VEERS SW AND BECOMES AIMED AT UPPER LAKES
WITH STRONGER MOISTURE ADVECTION. H85 JET AND CONVERGENCE WOULD
INTERACT WITH INSTABILITY ALOFT TO TRIGGER THE SHRA/TSRA.
ADDITIONALLY...MOST MODELS INDICATE H7-H5 Q-VECTOR CONVERGENCE
MOVING THROUGH WITH A STRONGER SHORTWAVE...AT LEAST COMPARED TO THE
WEAKER WAVES ON MON AND TUE. OVERALL...SEEMS THERE IS ENOUGH
EVIDENCE TO KEEP SMALL POPS IN FOR TUE NIGHT AND WED OVER THE WEST
AND FARTHER TO THE EAST ALONG LK SUPERIOR AND OVER LK SUPERIOR.
LATER ON WED...SFC BASED INSTABILITY SHRA/TSRA CHANCES LOOK SLIM AS
WITH SLOWER FRONTAL MOVEMENT TO THE EAST...GREATEST MLCAPES TOWARD
1000J/KG REMAIN OVER NEB/IA INTO MN.
LATE SUMMERTIME WARMTH PROBABLY ENDS UP BEING THE MAIN STORY FOR
MOST OF THE WEEK. NOT UNCOMMON TO SEE READINGS INTO THE 80S IN MID
SEPTEMBER AS RECORDS FOR 14-16 SEPT ARE STILL IN THE UPR 80S TO MID
90S FOR MANY LOCATIONS. FOR THIS WEEK...BASED ON H85 TEMPS OF AT
LEAST 16 ON TUE AND 18-20C WED AND THU...SHOULD SEE READINGS WELL
INTO THE 80S WITH EVEN A FEW LOW 90S POSSIBLE. NEED DEEPER MIXING TO
SEE THAT DEGREE OF WARMTH THOUGH AND ANY SIGNIFICANT MID CLOUDS WILL
DAMPEN THAT POTENTIAL. EVEN SO THOUGH...STEADY AND GUSTY AT TIMES S
TO SW WINDS IN TIGHER PRESSURE GRADIENT BTWN TROUGH OVER PLAINS AND
RIDGE OVER EASTERN CONUS RESULTS IN MINIMAL LAKE MODIFICATION AWAY
FM LK MICHIGAN SHORE AND WILL ALLOW DOWNSLOPE AREAS NEAR LK SUPERIOR
FM WEST ACROSS KEWEENAW TO NORTH CENTRAL TO SEE WARMEST TEMPS. EVEN
WITH THE WARMER TEMPS...HUMIDITY SHOULD REMAIN IN CHECK WITH DWPNTS
MOSTLY IN THE 50S. MOST HUMID DAY WOULD BE ON THU WITH DWPNTS INTO
THE 60S JUST AHEAD OF THE FRONT.
CONCERNING THE MAIN RAIN CHANCES THIS WEEK...MODELS STILL DIFFER ON
TIMING OF FROPA THU/FRI BUT THAT IS PRETTY TYPICAL FOR BEING THAT
FAR OUT. GFS IS QUICKER THAN ECMWF...WHICH IS ALSO A USUAL BIAS.
GIVEN THE UPPER LEVEL FLOW PATTERN EVEN ON THE GFS WITH BROAD TROUGH
OVER WESTERN CONUS AND RIDGE OVER THE EASTERN CONUS...GOING TO FAVOR
THE SLOWER ECMWF WITH ITS FROPA OCCURRING THU NIGHT INTO FRI. ALSO
SINCE UPPER TROUGH IS JUST DIGGING INTO THE UPPER LAKES ON FRIDAY
WITH FRONT STILL CLOSE BY...LIKE THE ECMWF STALLING THE FRONT OUT
AND ALLOWING FOR BETTER CHANCES OF RAIN ON FRIDAY. WILL TREND THAT
WAY FOR THIS FORECAST. THIS IDEA WHICH IS ALSO SUPPORTED BY THE GEM-
NH IS A NOTEABLE SLOWER TREND AS 24 HR AGO BOTH OF THESE MODELS
SHOWED FRONT/QPF MAINLY EAST OF CWA FOR FRIDAY. MUCAPES 0-3KM 1000-
2000J/KG AND SW LOW-LEVEL JET INTO THE UPPER GREAT LAKES SUPPORTS
TSRA TOO. SHEAR IS STRONGEST THU NIGHT OVERNIGHT INTO FRI WHICH IS
PROBABLY WHEN STRONG TO SEVERE STORMS COULD OCCUR SOMEWHERE OVER THE
REGION. PWATS OVER 1.50 INCHES WOULD ALSO SUPPORT HEAVY RAIN.
LATEST GEM-NH SUGGESTS LINGERING SHRA ON SATURDAY...BUT EVEN
EXTRAPOLATION OF THAT SOLN POINTS TO MOST OF THE DAY BEING DRY. KEPT
WITH CONSENSUS BUT REMOVED POPS IN THE AFTN. REST OF WEEKEND LOOKS
DRY BUT COOLER AS HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT.
TEMPS MAINLY WILL BE IN THE 60S. &&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 131 PM EDT SUN SEP 13 2015
UNDER DRY AIR MASS...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW
THRU THIS FCST PERIOD. INCREASING PRES GRADIENT WILL LEAD TO GUSTY
SW WINDS TO 15-20KT THIS AFTN AND DURING THE DAY ON MON...AND DEVELOPING
NOCTURNAL INVERSION THIS EVENING WILL LEAD TO LLWS AT ALL TERMINALS
TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 426 AM EDT SUN SEP 13 2015
IN GENERAL...FAIRLY WINDY CONDITIONS ARE SHAPING UP FOR LAKE
SUPERIOR THRU THE MIDWEEK PERIOD AS PATTERN FOR THE NEXT SEVERAL
DAYS WILL FEATURE HIGH PRES OFF TO THE SE AND E WITH A LOW PRES TROF
TO THE NW. EXPECT PERIODS OF 15-25KT AND EVEN 20-30KT S TO SW WINDS.
ONE PERIOD OF STRONGER WINDS WILL OCCUR TODAY THRU MONDAY MORNING
WITH THE STRONGEST WINDS OVER WESTERN LAKE SUPERIOR. THE NEXT PERIOD
OF STRONGER WINDS WILL OCCUR TUE AFTN THRU WED WITH THE STRONGEST
WINDS THIS TIME OVER EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 PM EDT SUN SEP 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 426 AM EDT SUN SEP 13 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF EXTENDING FROM THE
CNTRL GREAT LAKES S TO THE GULF COAST. TROF IS IMPRESSIVELY DEEP
OVER THE TENNESSEE VALLEY WHERE 500MB HEIGHT ANOMALIES ARE AT 5
STANDARD DEVIATIONS BLO THE LONG TERM MID SEPT AVG. MID LEVEL RIDGE
FROM THE NRN PLAINS TO NRN ONTARIO IS SUPPORTING SFC HIGH PRES RIDGE
EXTENDING FROM TX NE ACROSS ERN UPPER MI. ASSOCIATED DRY AIR
MASS/CLEAR SKIES/CALM WIND HAS ALLOWED TEMPS TO FALL DOWN INTO THE
30S OVER MUCH OF THE FCST AREA. TRADITIONAL COLD SPOTS HAVE FALLEN
TO AROUND FREEZING.
WITH DRY AIR DOMINATING THE SHORT TERM...NOT A WHOLE LOT TO TALK
ABOUT THIS MORNING. DEVELOPING SW FLOW BTWN DEPARTING HIGH PRES
RIDGE AND LOW PRES TROF MOVING ACROSS SCNTRL CANADA WILL RAISE 850MB
TEMPS FROM 4C E AND 8C W AT 12Z TO 9C E AND 12C W BY EVENING. THIS
WAA/ISENTROPIC ASCENT SHOULD YIELD A BAND OF SCT-BKN MID/HIGH CLOUDS
THAT WILL SPREAD WNW TO ESE ACROSS THE AREA TODAY. EXPECT MAX TEMPS
TO REBOUND INTO THE UPPER 60S TO MID 70S.
COMPARED TO CURRENT CONDITIONS EARLY THIS MORNING...TONIGHT WILL BE
MUCH WARMER. UNDER CLEAR SKIES...MIN TEMPS WILL BE MOSTLY IN THE
50S...WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. THE USUAL
INTERIOR COLD SPOTS WILL SLIP INTO THE UPPER 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 304 AM EDT SUN SEP 13 2015
THE COMING WORK WEEK WILL CERTAINLY BE MORE ACTIVE AND WARMER THAN
THIS WEEKEND. THE GENERAL PATTERN WILL START AS ZONAL AND FLOW WILL
BECOME MORE SWLY THROUGH THE WEEK AS TROUGHING DIGS INTO THE WRN
CONUS AND RIDGING BUILDS OVER THE E. MULTIPLE SHORTWAVES LOOK TO
THROUGH THE REGION THROUGH FRI AHEAD OF THE UPPER TROUGH. SHORTWAVES
WILL NOT HAVE A LOT OF MOISTURE TO WORK WITH...ESPECIALLY EARLY TO
MID WEEK. BETTER MOISTURE AND FORCING ARRIVE THU INTO FRI AS THE
UPPER TROUGH APPROACHES FROM THE W...SO CHANCES FOR WIDESPREAD
PRECIP WILL BE GREATER. FLOW NEXT WEEKEND LOOKS MORE ZONAL WITH SFC
HIGH PRESSURE TAKING CHARGE.
MOISTURE LOOKS TOO LIMITED FOR ANYTHING MORE THAN SOME ISOLATED
SHOWER ACTIVITY MON INTO WED...WHICH IS BACKED UP BE LIMITED MODEL
QPF DURING THIS TIME. 850MB TEMPS WILL BE ON THE INCREASE
MON...GOING FROM 12-18C IN THE MORNING TO 15-20C IN THE EVENING.
THIS WARMER AIRMASS STICKS AROUND THROUGH THU. EXACT TEMPS WILL
DEPEND ON PRECIP/CLOUD COVER WHICH WILL DEPEND ON SHORTWAVE
DETAILS...BUT GENERALLY SHOULD SEE HIGHS FROM THE MID 70S TO MID-
UPPER 80S...WARMEST IN DOWNSLOPING AREAS FROM SW WINDS.
COULD SEE BETTER PRECIP CHANCES LATE WED INTO WED NIGHT AS MOISTURE
IMPROVES SOMEWHAT AND OVERALL FORCING IMPROVES DUE TO STRONGER
SHORTWAVES MOVING NEARBY. STILL WILL HAVE ONLY SLIGHT CHANCE TO LOW
END CHANCE POPS GIVEN UNCERTAINTY WITH SHORTWAVE ENERGY.
MODELS ARE IN FAIR AGREEMENT THAT A STRONGER SHORTWAVE WILL DRIVE A
SFC LOW TO MOVE NW-N OF THE CWA THU INTO THU NIGHT...BRINGING A COLD
FRONT ACROSS THE AREA LATE THU INTO EARLY FRI. PRECIP LOOKS MORE
CERTAIN ALONG THE FRONT GIVEN THAT THE UPPER TROUGH APPROACHES THE
FRONT FROM THE W. THE GFS IS AROUND 6 HOURS FASTER THAN THE
ECMWF...BUT THAT IS MINOR AT THAT TIME RANGE. WILL USE A CONSENSUS
OF GUIDANCE DURING THIS TIME FRAME.
COOLER AND DRIER CONDITIONS ARE EXPECTED NEXT WEEKEND AS SFC HIGH
PRESSURE DOMINATES BEHIND THE COLD FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 131 PM EDT SUN SEP 13 2015
UNDER DRY AIR MASS...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW
THRU THIS FCST PERIOD. INCREASING PRES GRADIENT WILL LEAD TO GUSTY
SW WINDS TO 15-20KT THIS AFTN AND DURING THE DAY ON MON...AND DEVELOPING
NOCTURNAL INVERSION THIS EVENING WILL LEAD TO LLWS AT ALL TERMINALS
TONIGHT. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 426 AM EDT SUN SEP 13 2015
IN GENERAL...FAIRLY WINDY CONDITIONS ARE SHAPING UP FOR LAKE
SUPERIOR THRU THE MIDWEEK PERIOD AS PATTERN FOR THE NEXT SEVERAL
DAYS WILL FEATURE HIGH PRES OFF TO THE SE AND E WITH A LOW PRES TROF
TO THE NW. EXPECT PERIODS OF 15-25KT AND EVEN 20-30KT S TO SW WINDS.
ONE PERIOD OF STRONGER WINDS WILL OCCUR TODAY THRU MONDAY MORNING
WITH THE STRONGEST WINDS OVER WESTERN LAKE SUPERIOR. THE NEXT PERIOD
OF STRONGER WINDS WILL OCCUR TUE AFTN THRU WED WITH THE STRONGEST
WINDS THIS TIME OVER EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
717 AM EDT SUN SEP 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 426 AM EDT SUN SEP 13 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF EXTENDING FROM THE
CNTRL GREAT LAKES S TO THE GULF COAST. TROF IS IMPRESSIVELY DEEP
OVER THE TENNESSEE VALLEY WHERE 500MB HEIGHT ANOMALIES ARE AT 5
STANDARD DEVIATIONS BLO THE LONG TERM MID SEPT AVG. MID LEVEL RIDGE
FROM THE NRN PLAINS TO NRN ONTARIO IS SUPPORTING SFC HIGH PRES RIDGE
EXTENDING FROM TX NE ACROSS ERN UPPER MI. ASSOCIATED DRY AIR
MASS/CLEAR SKIES/CALM WIND HAS ALLOWED TEMPS TO FALL DOWN INTO THE
30S OVER MUCH OF THE FCST AREA. TRADITIONAL COLD SPOTS HAVE FALLEN
TO AROUND FREEZING.
WITH DRY AIR DOMINATING THE SHORT TERM...NOT A WHOLE LOT TO TALK
ABOUT THIS MORNING. DEVELOPING SW FLOW BTWN DEPARTING HIGH PRES
RIDGE AND LOW PRES TROF MOVING ACROSS SCNTRL CANADA WILL RAISE 850MB
TEMPS FROM 4C E AND 8C W AT 12Z TO 9C E AND 12C W BY EVENING. THIS
WAA/ISENTROPIC ASCENT SHOULD YIELD A BAND OF SCT-BKN MID/HIGH CLOUDS
THAT WILL SPREAD WNW TO ESE ACROSS THE AREA TODAY. EXPECT MAX TEMPS
TO REBOUND INTO THE UPPER 60S TO MID 70S.
COMPARED TO CURRENT CONDITIONS EARLY THIS MORNING...TONIGHT WILL BE
MUCH WARMER. UNDER CLEAR SKIES...MIN TEMPS WILL BE MOSTLY IN THE
50S...WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. THE USUAL
INTERIOR COLD SPOTS WILL SLIP INTO THE UPPER 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 304 AM EDT SUN SEP 13 2015
THE COMING WORK WEEK WILL CERTAINLY BE MORE ACTIVE AND WARMER THAN
THIS WEEKEND. THE GENERAL PATTERN WILL START AS ZONAL AND FLOW WILL
BECOME MORE SWLY THROUGH THE WEEK AS TROUGHING DIGS INTO THE WRN
CONUS AND RIDGING BUILDS OVER THE E. MULTIPLE SHORTWAVES LOOK TO
THROUGH THE REGION THROUGH FRI AHEAD OF THE UPPER TROUGH. SHORTWAVES
WILL NOT HAVE A LOT OF MOISTURE TO WORK WITH...ESPECIALLY EARLY TO
MID WEEK. BETTER MOISTURE AND FORCING ARRIVE THU INTO FRI AS THE
UPPER TROUGH APPROACHES FROM THE W...SO CHANCES FOR WIDESPREAD
PRECIP WILL BE GREATER. FLOW NEXT WEEKEND LOOKS MORE ZONAL WITH SFC
HIGH PRESSURE TAKING CHARGE.
MOISTURE LOOKS TOO LIMITED FOR ANYTHING MORE THAN SOME ISOLATED
SHOWER ACTIVITY MON INTO WED...WHICH IS BACKED UP BE LIMITED MODEL
QPF DURING THIS TIME. 850MB TEMPS WILL BE ON THE INCREASE
MON...GOING FROM 12-18C IN THE MORNING TO 15-20C IN THE EVENING.
THIS WARMER AIRMASS STICKS AROUND THROUGH THU. EXACT TEMPS WILL
DEPEND ON PRECIP/CLOUD COVER WHICH WILL DEPEND ON SHORTWAVE
DETAILS...BUT GENERALLY SHOULD SEE HIGHS FROM THE MID 70S TO MID-
UPPER 80S...WARMEST IN DOWNSLOPING AREAS FROM SW WINDS.
COULD SEE BETTER PRECIP CHANCES LATE WED INTO WED NIGHT AS MOISTURE
IMPROVES SOMEWHAT AND OVERALL FORCING IMPROVES DUE TO STRONGER
SHORTWAVES MOVING NEARBY. STILL WILL HAVE ONLY SLIGHT CHANCE TO LOW
END CHANCE POPS GIVEN UNCERTAINTY WITH SHORTWAVE ENERGY.
MODELS ARE IN FAIR AGREEMENT THAT A STRONGER SHORTWAVE WILL DRIVE A
SFC LOW TO MOVE NW-N OF THE CWA THU INTO THU NIGHT...BRINGING A COLD
FRONT ACROSS THE AREA LATE THU INTO EARLY FRI. PRECIP LOOKS MORE
CERTAIN ALONG THE FRONT GIVEN THAT THE UPPER TROUGH APPROACHES THE
FRONT FROM THE W. THE GFS IS AROUND 6 HOURS FASTER THAN THE
ECMWF...BUT THAT IS MINOR AT THAT TIME RANGE. WILL USE A CONSENSUS
OF GUIDANCE DURING THIS TIME FRAME.
COOLER AND DRIER CONDITIONS ARE EXPECTED NEXT WEEKEND AS SFC HIGH
PRESSURE DOMINATES BEHIND THE COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 716 AM EDT SUN SEP 13 2015
UNDER DRY AIR MASS...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW
THRU THIS FCST PERIOD. INCREASING PRES GRADIENT WILL LEAD TO GUSTY
SW WINDS TO 15-20KT THIS AFTN...AND THEN DEVELOPING NOCTURNAL
INVERSION THIS EVENING WILL LEAD TO LLWS AT ALL TERMINALS TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 426 AM EDT SUN SEP 13 2015
IN GENERAL...FAIRLY WINDY CONDITIONS ARE SHAPING UP FOR LAKE
SUPERIOR THRU THE MIDWEEK PERIOD AS PATTERN FOR THE NEXT SEVERAL
DAYS WILL FEATURE HIGH PRES OFF TO THE SE AND E WITH A LOW PRES TROF
TO THE NW. EXPECT PERIODS OF 15-25KT AND EVEN 20-30KT S TO SW WINDS.
ONE PERIOD OF STRONGER WINDS WILL OCCUR TODAY THRU MONDAY MORNING
WITH THE STRONGEST WINDS OVER WESTERN LAKE SUPERIOR. THE NEXT PERIOD
OF STRONGER WINDS WILL OCCUR TUE AFTN THRU WED WITH THE STRONGEST
WINDS THIS TIME OVER EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 AM EDT SUN SEP 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 426 AM EDT SUN SEP 13 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF EXTENDING FROM THE
CNTRL GREAT LAKES S TO THE GULF COAST. TROF IS IMPRESSIVELY DEEP
OVER THE TENNESSEE VALLEY WHERE 500MB HEIGHT ANOMALIES ARE AT 5
STANDARD DEVIATIONS BLO THE LONG TERM MID SEPT AVG. MID LEVEL RIDGE
FROM THE NRN PLAINS TO NRN ONTARIO IS SUPPORTING SFC HIGH PRES RIDGE
EXTENDING FROM TX NE ACROSS ERN UPPER MI. ASSOCIATED DRY AIR
MASS/CLEAR SKIES/CALM WIND HAS ALLOWED TEMPS TO FALL DOWN INTO THE
30S OVER MUCH OF THE FCST AREA. TRADITIONAL COLD SPOTS HAVE FALLEN
TO AROUND FREEZING.
WITH DRY AIR DOMINATING THE SHORT TERM...NOT A WHOLE LOT TO TALK
ABOUT THIS MORNING. DEVELOPING SW FLOW BTWN DEPARTING HIGH PRES
RIDGE AND LOW PRES TROF MOVING ACROSS SCNTRL CANADA WILL RAISE 850MB
TEMPS FROM 4C E AND 8C W AT 12Z TO 9C E AND 12C W BY EVENING. THIS
WAA/ISENTROPIC ASCENT SHOULD YIELD A BAND OF SCT-BKN MID/HIGH CLOUDS
THAT WILL SPREAD WNW TO ESE ACROSS THE AREA TODAY. EXPECT MAX TEMPS
TO REBOUND INTO THE UPPER 60S TO MID 70S.
COMPARED TO CURRENT CONDITIONS EARLY THIS MORNING...TONIGHT WILL BE
MUCH WARMER. UNDER CLEAR SKIES...MIN TEMPS WILL BE MOSTLY IN THE
50S...WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. THE USUAL
INTERIOR COLD SPOTS WILL SLIP INTO THE UPPER 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 304 AM EDT SUN SEP 13 2015
THE COMING WORK WEEK WILL CERTAINLY BE MORE ACTIVE AND WARMER THAN
THIS WEEKEND. THE GENERAL PATTERN WILL START AS ZONAL AND FLOW WILL
BECOME MORE SWLY THROUGH THE WEEK AS TROUGHING DIGS INTO THE WRN
CONUS AND RIDGING BUILDS OVER THE E. MULTIPLE SHORTWAVES LOOK TO
THROUGH THE REGION THROUGH FRI AHEAD OF THE UPPER TROUGH. SHORTWAVES
WILL NOT HAVE A LOT OF MOISTURE TO WORK WITH...ESPECIALLY EARLY TO
MID WEEK. BETTER MOISTURE AND FORCING ARRIVE THU INTO FRI AS THE
UPPER TROUGH APPROACHES FROM THE W...SO CHANCES FOR WIDESPREAD
PRECIP WILL BE GREATER. FLOW NEXT WEEKEND LOOKS MORE ZONAL WITH SFC
HIGH PRESSURE TAKING CHARGE.
MOISTURE LOOKS TOO LIMITED FOR ANYTHING MORE THAN SOME ISOLATED
SHOWER ACTIVITY MON INTO WED...WHICH IS BACKED UP BE LIMITED MODEL
QPF DURING THIS TIME. 850MB TEMPS WILL BE ON THE INCREASE
MON...GOING FROM 12-18C IN THE MORNING TO 15-20C IN THE EVENING.
THIS WARMER AIRMASS STICKS AROUND THROUGH THU. EXACT TEMPS WILL
DEPEND ON PRECIP/CLOUD COVER WHICH WILL DEPEND ON SHORTWAVE
DETAILS...BUT GENERALLY SHOULD SEE HIGHS FROM THE MID 70S TO MID-
UPPER 80S...WARMEST IN DOWNSLOPING AREAS FROM SW WINDS.
COULD SEE BETTER PRECIP CHANCES LATE WED INTO WED NIGHT AS MOISTURE
IMPROVES SOMEWHAT AND OVERALL FORCING IMPROVES DUE TO STRONGER
SHORTWAVES MOVING NEARBY. STILL WILL HAVE ONLY SLIGHT CHANCE TO LOW
END CHANCE POPS GIVEN UNCERTAINTY WITH SHORTWAVE ENERGY.
MODELS ARE IN FAIR AGREEMENT THAT A STRONGER SHORTWAVE WILL DRIVE A
SFC LOW TO MOVE NW-N OF THE CWA THU INTO THU NIGHT...BRINGING A COLD
FRONT ACROSS THE AREA LATE THU INTO EARLY FRI. PRECIP LOOKS MORE
CERTAIN ALONG THE FRONT GIVEN THAT THE UPPER TROUGH APPROACHES THE
FRONT FROM THE W. THE GFS IS AROUND 6 HOURS FASTER THAN THE
ECMWF...BUT THAT IS MINOR AT THAT TIME RANGE. WILL USE A CONSENSUS
OF GUIDANCE DURING THIS TIME FRAME.
COOLER AND DRIER CONDITIONS ARE EXPECTED NEXT WEEKEND AS SFC HIGH
PRESSURE DOMINATES BEHIND THE COLD FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1250 AM EDT SUN SEP 13 2015
WITH ONE EXCEPTION...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD
AT KIWD/KCMX/KSAW. THERE MAY BE SOME SHALLOW FOG AT KSAW LATE IN THE
NIGHT/EARLY MORNING BUT THE PROBABILIITY OF VSBY REDUCTION IS TOO LOW
FOR MENTION AT THIS TIME. SHALLOW FOG (MVFR VIS) AT KIWD SHOULD
DISSIPATE OVER THE NEXT FEW HRS AS SSW WINDS DEVELOP.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 426 AM EDT SUN SEP 13 2015
IN GENERAL...FAIRLY WINDY CONDITIONS ARE SHAPING UP FOR LAKE
SUPERIOR THRU THE MIDWEEK PERIOD AS PATTERN FOR THE NEXT SEVERAL
DAYS WILL FEATURE HIGH PRES OFF TO THE SE AND E WITH A LOW PRES TROF
TO THE NW. EXPECT PERIODS OF 15-25KT AND EVEN 20-30KT S TO SW WINDS.
ONE PERIOD OF STRONGER WINDS WILL OCCUR TODAY THRU MONDAY MORNING
WITH THE STRONGEST WINDS OVER WESTERN LAKE SUPERIOR. THE NEXT PERIOD
OF STRONGER WINDS WILL OCCUR TUE AFTN THRU WED WITH THE STRONGEST
WINDS THIS TIME OVER EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
643 PM CDT MON SEP 14 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM CDT MON SEP 14 2015
A WEAK FRONT DRAPED ACROSS THE REGION TODAY HAS BEEN FAIRLY
INACTIVE...WITH AN AREA OF STRATUS TO ITS NORTH THAT HAS BEEN
KEEPING TEMPERATURES COOL ALONG THE CANADIAN BORDER. HAVE BEEN
WATCHING SOME CHAFF ON THE RADAR OVER THE NORTH SHORE THAT WAS
INITIALLY CONCERNING DUE TO ITS PROXIMITY TO THE FRONT...BUT THERE
ARE NO CLOUDS ACCORDING TO SATELLITE AND DO NOT EXPECT ANY TO FORM.
SOME WEAK/ELEVATED SHOWERS HAVE FORMED FARTHER WEST ALONG THE BORDER
IN THE DETROIT LAKES AREA. THESE DO NOT HAVE MUCH FOR CAPE TO
PRODUCE MORE THAN A FEW SHOWERS...SO HAVE KEPT POPS TO SLIGHTS AND
ONLY FOR THE NEXT FEW HOURS AND HAVE NOT PUT IN ANY THUNDER. THE
NEXT SIGNIFICANT CONCERN TONIGHT IS THE STRATUS ALONG THE CANADIAN
BORDER. MODELS HAVE BEEN HANDLING THIS VERY POORLY IN GENERAL...BUT
EXPECT THAT IF THE STRATUS HAS NOT DISSIPATED IN THE NEXT FEW HOURS
IT WILL NOT...AND SHOULD BEGIN EXPANDING AGAIN AFTER SUNSET. LOW
LEVEL RH PROGS ARE IMPLYING WE WILL HAVE AN AREA OF STRATUS ALONG
THE CANADIAN BORDER FOR MUCH OF THE NIGHT...AND IT MAY EXPAND DOWN
TO AROUND THE IRON RANGE AFTER MIDNIGHT. HAVE GONE FAIRLY
PESSIMISTIC ON CLOUD COVER OVERNIGHT...AND WOULD NOT BE SURPRISED TO
SEE SOME SPRINKLES UP THERE TOWARDS MORNING. WITH ALL THE LOW LEVEL
RH...SOME FOG IS POSSIBLE SO HAVE PUT IN PATCHY FOG OVERNIGHT FOR
THE NORTH AS WELL. SOUTHERN PORTIONS OF THE FORECAST AREA SHOULD
STAY MOSTLY CLEAR AND DRY OVERNIGHT. TUESDAY THE FRONT PUSHES FAR
ENOUGH NORTH THAT WE SHOULD BE DRY AND EVEN CLEAR OUT. WE SHOULD
HAVE A WARM AND SOMEWHAT UNSTABLE AIRMASS...BUT IT WILL BE WEAKLY
CAPPED AND WITH NO SURFACE FEATURE TO HELP TRIGGER CONVECTION DO NOT
EXPECT ANY STORMS DURING THE DAY. HIGHS TUESDAY TO BE PUSHING
80...EVEN ACROSS THE NORTH AS LONG AS CLOUD COVER CLEARS OUT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM CDT MON SEP 14 2015
THE NORTHLAND WILL BE IN AN ACTIVE...WARM AND POTENTIALLY
STORMY...WEATHER PATTERN FOR THE MIDDLE OF THE WEEK. THE NORTHLAND
CAN EXPECT TEMPERATURES OF ABOUT 10 DEGREES ABOVE NORMAL FOR THE
MIDDLE OF THE WEEK THROUGH THURSDAY...WITH 850 HPA TEMPERATURES OF
ABOUT 15 TO 19 DEGREES CELSIUS. COOLER AND DRIER AIR WILL MOVE INTO
THE NORTHLAND LATER IN THE WEEK.
A STRONG SOUTHERLY LOW LEVEL JET WILL DEVELOP TUESDAY NIGHT AS A LOW
IN NORTH DAKOTA LIFTS INTO CANADA. THE MODELS ARE SUGGESTING THERE
COULD BE CONVECTION OVERNIGHT INTO EARLY WEDNESDAY WITH THE STRONG
JET. THE SOUTHERLY FLOW WILL BRING VERY HUMID AIR INTO THE REGION.
PRECIPITABLE WATER VALUES WILL LIKELY INCREASE TO AT LEAST THE 90TH
PERCENTILE OF CLIMATOLOGY.
THE LOW WILL LIFT INTO ONTARIO ON WEDNESDAY...AND ITS COLD FRONT
WILL MOVE INTO MINNESOTA AND THEN STALL SOMEWHERE OVER NORTHERN
MINNESOTA. THIS MEANS THE NORTHLAND WILL LIKELY REMAIN IN THE WARM
AND HUMID ZONE...AND WILL PROVIDE LOW CHANCES OF SHOWERS AND STORMS
OVER PARTS OF THE FORECAST AREA WEDNESDAY AND WEDNESDAY EVENING.
THE HIGHEST CHANCES OF SHOWERS AND STORMS WILL OCCUR LATE WEDNESDAY
NIGHT AND THURSDAY. THE GFS/ECMWF/GEM ARE INDICATING ANOTHER SURGE
OF WARM AND HUMID AIR WILL ACCOMPANY THE SOUTHERLY FLOW LATE
WEDNESDAY NIGHT AND THURSDAY AS ANOTHER LOW MOVES INTO THE NORTHERN
PLAINS. ITS COLD FRONT WILL THEN MOVE THROUGH THE NORTHLAND LATER IN
THE DAY ON THURSDAY AND OVERNIGHT INTO EARLY FRIDAY. INCREASED PCPN
CHANCES FOR THURSDAY AND THURSDAY NIGHT BASED ON A BLEND OF THE
GFS/ECMWF/GEM...WHICH ARE IN REASONABLE AGREEMENT.
FRIDAY WILL BE MUCH COOLER THAN THE MIDDLE OF THE WEEK. NW FLOW WILL
DEVELOP IN THE WAKE OF THE PASSING COLD FRONT...USHERING IN MORE
SEASONABLY APPROPRIATE 850 HPA TEMPERATURES OF 5 TO 7 DEGREES
CELSIUS. THE COOL FLOW...AND HUMIDITY FROM THE RAIN THE PREVIOUS
NIGHT...COULD RESULT IN WIDESPREAD BROKEN/OVERCAST CUMULUS DURING
THE DAY.
FOR THE UPCOMING WEEKEND...THE LATEST AND PREVIOUS GFS/EURO/GEM
GUIDANCE ARE SURPRISINGLY IN EXCELLENT AGREEMENT FOR THE FALL. AS A
RESULT FAIRLY CONFIDENT WITH A TROUGH EXITING THE FORECAST AREA
EARLY ON SATURDAY. BEHIND THE TROUGH...A RIDGE WILL BUILD IN FROM
THE WEST. BY LATE ON SATURDAY THE 500 HPA RIDGE AXIS WILL BE NEAR
THE EASTERN NORTHERN PLAINS OR OVER THE UPPER MIDWEST. AT 850 AND
925 HPA...WARM AIR ADVECTION WILL OCCUR LATE ON SATURDAY AND FOR THE
REST OF SUNDAY. AS A RESULT EXPECTING SEASONABLE TEMPERATURES ON
SATURDAY IN WAKE OF THE DEPARTING FRONT WITH READINGS IN THE 60S. ON
SUNDAY IT WILL BE MILDER WITH TEMPERATURES IN THE UPPER 60S AND LOW
70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 636 PM CDT MON SEP 14 2015
MVFR CEILINGS ALONG THE INTERNATIONAL BORDER WERE MOVING NORTH AND
SHOULD MOVE OUT OF KINL OVER THE NEXT 1 TO 2 HOURS. VFR CONDITIONS
WERE OCCURRING ELSEWHERE. A FRONTAL BOUNDARY WAS DRAPED ACROSS
NORTHERN MINNESOTA AS WELL THIS EVENING AND WE HAVE SEEN SOME
CLOUDS FORM ALONG IT. THE FRONT WILL MOVE BACK TO THE NORTH
TONIGHT TO NEAR THE INTERNATIONAL BORDER BY 12Z TUE.
CONFIDENCE IN LOWER CLOUD FORMATION TONIGHT IS LOWER THAN AVERAGE.
THE RAP WHICH HAS A GOOD HANDLE ON THE CURRENT MVFR CEILINGS IS
NOT VERY SUPPORTIVE OF ADDITIONAL DEVELOPMENT TONIGHT...AND THE
HRRR AGREES. THE SREF/NAM SUGGEST IFR/LOW MVFR CONDITIONS WILL
DEVELOP OVERNIGHT ALONG WITH SOME FOG. WE MADE SOME MINOR
ADJUSTMENTS IN THIS SET OF TAFS AND STILL FORECAST SOME LOWER
CLOUDS/FOG. AN INCREASING GRADIENT WILL LEAD TO VFR CONDITIONS
TUESDAY MORNING AS MIXING DEEPENS AND WINDS STRENGTHEN.
A LLJ WILL LEAD TO SOME LLWS IN SPOTS LATER TONIGHT TO ABOUT 14Z
TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 60 77 64 78 / 10 10 30 30
INL 56 76 65 78 / 10 10 20 30
BRD 63 79 67 81 / 10 10 20 20
HYR 62 79 65 80 / 0 10 30 20
ASX 60 82 64 81 / 0 10 30 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...LE
LONG TERM...GROCHOCINSKI/WL
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS ELKO NV
740 PM PDT MON SEP 14 2015
SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL IMPACT THE GREAT BASIN
THE NEXT FEW DAYS. THIS LOW WILL BE SLOW TO CLEAR AND A SECOND
SURGE OF PACIFIC MOISTURE WILL FOLLOW IN ITS WAKE. FRIDAY WILL BE
THE DRIEST DAY THIS WORK WEEK.
&&
.UPDATE...ALLOWED WIND ADVISORY TO EXPIRE AT 8 PM FOR WHITE PINE
AND NORTHEAST NYE COUNTIES. NO OTHER CHANGES.
&&
.PREV DISCUSSION... /ISSUED AT 312 PM /
SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL IMPACT THE GREAT BASIN
THE NEXT FEW DAYS. THIS LOW WILL BE SLOW TO CLEAR AND A SECOND
SURGE OF PACIFIC MOISTURE WILL FOLLOW IN ITS WAKE. FRIDAY WILL BE
THE DRIEST DAY THIS WORK WEEK.
SHORT TERM...TONIGHT THROUGH WEDNESDAY. UNSETTLED WEATHER IS ON
DECK THIS FORECAST PERIOD...SEVERAL SWA`S HAVE ALREADY BEEN ISSUED
THIS AFTERNOON. THE LATEST RUN OF THE HRRR HAS A WELL DEFINED
QPF SWATH FROM ELKO COUNTY TO LANDER COUNTY...WHICH IS IN LOCK
STEP WITH THE NAM`S AREA OF CONVERGENCE ON THE 700 MB STREAMLINE
ANALYSIS. EXPECTING MODIFIED PACIFIC AIRMASS TO COLLIDE WITH
SUBTROPICAL MOISTURE OVER THE LKN CWA THIS FORECAST PERIOD...WITH
ADDITIONAL ENHANCEMENT FROM AN INCOMING VORT MAX. PWS ARE WELL
ABOVE NORMAL THIS ENTIRE FORECAST PERIOD RANGING 2 TO 3 STANDARD
DEVIATIONS ABOVE NORMAL ON THE NAEFS STANDARDIZED ANOMALIES...WITH
A RETURN INTERVAL OF TWO TO FIVE YEARS. ADDITIONALLY...WITH THE
GRADIENT TIGHTENING AS THE UPPER TROF MOVES INLAND...THE U AND V
COMPONENT ANOMALIES SPIKE AGAIN THIS FORECAST PERIOD...PINGING
INTO A 5 YEAR RETURN INTERVAL. THE CAVEAT BEING CLOUD COVERAGE
INHIBITING WINDS FROM MIXING DOWN.
LONG TERM...WEDNESDAY NIGHT THROUGH NEXT MONDAY. MODELS IN GOOD
AGREEMENT THROUGH THE PERIOD WITH ONLY MINOR DIFFERENCES.
TIMING OF SHORT WAVES ORBITING AROUND THE PACNW FULL TROUGH IS THE
PROBLEM O` THE DAY. WITH TIME AND STRENGTH BEING THE ISSUE...WILL
BROADBRUSH A BIT. NO LARGE CHANGES FROM PREVIOUS PACKAGE. RAISED
SNOW LEVELS A HAIR OVER PREVIOUS THINKING AS TONS OF COLD AIR DOES
NOT APPEAR TO WANT TO FILTER INTO THE REGION. CERTAINLY SNOW LEVELS
WILL DROP TO BELOW 9000 IN PLACES IN THE NORTH BUT MOST WILL BE WELL
AWAY FROM ROADS AND POPULATED PLACES. LATE SUMMER MOUNTAIN SNOWS
ARE NICE...UNLESS YOU ARE HUNTING OR HIKING. USE CAUTION.
LONG RANGE STARTS OUT WITH SOME RESIDUAL MOISTURE AND INSTABILITY
AND DYNAMICS SUFFICIENT TO PRODUCE SHOWERS OVER THE NORTHWEST AND
SOME THUNDERSTORMS/SHOWERS OVER THE SOUTHEAST HALF. THIS QUICKLY
DIES DOWN AS MOISTURE MOVE EAST AND MAIN DYNAMIC ROTATE NORTHEAST
OUT OF THE AREA. THEREAFTER...DRYING AND SLOW WARMING TREND. WINDS
WILL BE GUSTY IN THE BEGINNING AND THEN ALSO DIMINISH.
AVIATION...CLOUDS WILL INCREASE BUT WILL STAY VFR DURING THE DAY
WITH -SHRA AND TS POSSIBLE AT ALL TAF SITES WITH CHANCES AT 30 TO 40
PERCENT. GUSTY WINDS S-SW TODAY ESPECIALLY AT KELY AND KTPH WHERE
GUSTS TO 30 TO 35 KNOTS A GOOD BET. STORMS WILL PRODUCE BRIEF HEAVY
RAINS IN SPOTS. AIRFIELDS MAY GET STANDING WATER AT TIMES.
CONVECTION LASTS OVERNIGHT BUT DIMINISHES BEFORE FIRING UP AGAIN
TUESDAY.
FIRE WEATHER...ACTIVE WEATHER RETURNS TO IMPACT THE SILVER
STATE. EXPECT MOISTURE FROM THE PACIFIC NORTHWEST TO MARRY UP WITH
MOISTURE FROM THE REMNANTS OF TROPICAL STORM LINDA. MULTIPLE SWA`S
HAVE BEEN ISSUED FOR STORMS THAT HAVE DEVELOPED OVER NORTHERN
NEVADA TODAY. EXPECT THE MOISTURE TO LINGER...WHICH WILL FUEL TSRA
THE NEXT 60 HRS...RESULTING IN ENAHANCED LALS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
90/99
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
927 PM MDT MON SEP 14 2015
.UPDATE...
THOUGH QUITE A BIT OF CLOUD COVER REMAINS ACROSS THE CWA...VERY
FEW SHOWERS AND THUNDERSTORMS REMAIN. ANOTHER SHORTWAVE WILL CROSS
NW NM TONIGHT...AND IS CURRENTLY ASSOCIATED WITH THE BROKEN LINE
OF CONVECTION ACROSS AZ. THIS LINE SHOULD CONTINUE TO TRACK
NE...BUT WILL BARELY BE MAKING IT TO THE NM DOORSTEP BY 12Z...AND
MODELS GENERALLY INDICATE IT WILL WEAKEN BEFORE CROSSING NM.
THUS...HAVE REDUCED POPS FOR THE REMAINDER OF THE OVERNIGHT...AND
THE HRRR INDICATES POPS COULD HAVE BEEN REDUCED FURTHER. DRIER
CONDITIONS STILL ON TAP FOR TUESDAY.
34
&&
.PREV DISCUSSION...550 PM MDT MON SEP 14 2015...
.AVIATION...
00Z TAF CYCLE
-SHRA WITH GUSTY OUTFLOWS RELEGATED TO AREAS ALONG AND NORTH OF
THE I-40 THRU THIS EVENING. ACTIVITY WILL TAPER ALL AREAS EXCEPT
NORTHWEST NM WHERE UPSLOPE FLOW WILL FAVOR CONTINUED -SHRA AND
PERHAPS A LCL -TSRA THRU SUNRISE. THICK MID LEVEL CLOUDS EXPECTED
TO HANG AROUND MANY AREAS OF CENTRAL AND WESTERN NM THRU SUNRISE.
DRY AND MORE STABLE AIR INVADING FROM THE WEST TUESDAY WILL CAP
-SHRA DEVELOPMENT JUST ABOUT EVERYWHERE. A DEEPENING LEE TROUGH
OUT EAST WILL ALLOW FOR BREEZY SW WINDS DURING THE MID TO LATE
AFTERNOON HOURS. 42
&&
.PREV DISCUSSION...332 PM MDT MON SEP 14 2015...
.SYNOPSIS...
AN UPPER LEVEL TROUGH TRAVERSING THE CENTRAL AND NORTHERN ROCKIES
FROM CALIFORNIA WILL SHOULD DRAW ENOUGH MOISTURE NORTHWARD FOR A
BRIEF UPTICK IN SHOWER AND THUNDERSTORM COVERAGE ACROSS NORTHWEST
AND WEST CENTRAL NEW MEXICO TONIGHT. PRECIPITATION CHANCES WILL
TREND DOWNWARD TUESDAY THROUGH MID WEEK AS DRIER AIR MOVES OVER
THE STATE FROM THE SOUTHWEST. A ROLLER COASTER OF TEMPERATURES IS
EXPECTED AS HIGHS FALL SOME TUESDAY...RISE A BIT MOST PLACES
THROUGH MID WEEK...THEN FALL MORE SIGNIFICANTLY FRIDAY AND
SATURDAY AS A BACK DOOR COLD FRONT PLUNGES THROUGH THE STATE.
MODEST MOISTURE ARRIVING WITH THE FRONT...AND SOME ELEVATED
MOISTURE TRAVELING NORTHWARD FROM MEXICO...SHOULD FEED BETTER
COVERAGE OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF THE
CONTINENTAL DIVIDE TO THE TEXAS BOARDER THIS WEEKEND.
&&
.DISCUSSION...
THE DRY SLOT HEADED THIS WAY THIS AFTERNOON LOOKS PRETTY
IMPRESSIVE ON WATER VAPOR IMAGERY. THE BEST CHANCE FOR SHOWERS
AND STORMS FORMING MAINLY OVER NW AREAS SHOULD BE THIS EVENING
JUST BEFORE THE DRIER AIR ALOFT ARRIVES.
A BROAD TROUGH OVER THE W COAST AND GREAT BASIN WILL DEEPEN
TUESDAY AND WEDNESDAY...FLATTENING OUT THE MID LEVEL HIGH SE OF
NEW MEXICO SO THE RIDGE AXIS CUTS OFF THE ELEVATED NORTHWARD
MOISTURE FLUX FROM MEXICO. STRENGTHENING SW FLOW ALOFT SHOULD
RESULT IN SOME FAIRLY BREEZY CONDITIONS ALONG AND NORTH OF I-40
TUESDAY AND ESPECIALLY WEDNESDAY WHEN ATMOSPHERIC MIXING WILL
IMPROVE. HIGH TEMPERATURES ACROSS THE PLAINS SHOULD VARY AROUND 5
TO 12 DEGREES ABOVE NORMAL TUESDAY THROUGH THURSDAY.
TEMPERATURES WILL THEN TREND DOWNWARD WITH THE BACK DOOR FRONT...AND
MOISTURE WILL IMPROVE ACROSS CENTRAL AND EASTERN AREAS AT THE END
OF THE WEEK. MODEL QPF FIELDS LOOK PRETTY LIGHT...SO RAIN AMOUNTS
THIS WEEKEND SHOULD GENERALLY BE LIGHT...THOUGH THE COVERAGE
INCREASE SHOULD BE NOTABLE. 44
&&
.FIRE WEATHER...
MODERATE INCREASE IN MOISTURE UNDERWAY ACROSS ROUGHLY THE NW THIRD
OF NM...LESS SO ACROSS THE REST OF THE STATE. ISOLATED TO...AT
TIMES...SCATTERED SHOWERS AND STORMS ACROSS MAINLY THE NW THIRD OF
NM THIS AFTN AND INTO MID EVE SHOULD DIMINISH TO A LARGE DEGREE
THEREAFTER...LEAVING A FEW LINGERING LIGHT SHOWERS. WHILE A FEW
SPOTS SHOULD SEE SOME LOW END WETTING RAINFALL...MAJORITY OF LOCALES
WILL NOT. RH RECOVERIES SHOULD BE AT LEAST A LITTLE BETTER ACROSS NW
HALF OF FCST AREA TONIGHT VERSUS SUN NIGHT. A FEW SPOTS ACROSS THE
EASTERN PLAINS MAY SEE AN HOUR OR TWO OF VERY LOW END CRITICAL FIRE
WEATHER CONDITIONS DUE TO WINDS AND LOW RH BETWEEN MID AND LATE AFTN
TODAY.
WINDS ALOFT EXPECTED TO PICK UP A BIT MORE TUE OVER MOST OF FCST
AREA AS SOMEWHAT DRIER AIR INVADES. WIND DIRECTION WILL REMAIN
SOUTHWESTERLY ACROSS THE FORECAST AREA INTO TUE...BUT SPEEDS WILL
RAMP UP A BIT...IN THE VICINITY OF 20 TO 25 MPH IN SOME NORTHEASTERN
AND NORTHWESTERN ZONES AND HIGHER TERRAIN OF N CENTRAL NM. WHILE
WINDS WILL LIKELY REACH AT LEAST LOW END CRITICAL THRESHOLDS...RH
VALUES ARE EXPECTED TO GENERALLY HOVER IN THE 18 TO JUST OVER 30
PERCENT RANGE...A BIT HIGHER THAN THE CRITICAL THRESHOLD OF 15
PERCENT. AFTN TEMPS TO BE NEAR TO SLIGHTLY LOWER THAN TODAY AND WHAT
FEW SHOWERS AND STORMS DO DEVELOP...FEWER THAN TODAY...WILL AGAIN BE
MAINLY IN THE WEST CENTRAL TO NW AND NORTH CENTRAL ZONES.
WED AND THU WILL BRING EVEN A LITTLE MORE DRYING AND EVEN FEWER...IF
ANY...WETTING RAIN CHANCES. WIND SPEEDS ALOFT WILL PERHAPS DECLINE
JUST A BIT...BUT BREEZY TO LOW END WINDY CONDITIONS LIKELY TO RETURN
AT THE SURFACE AND 20FT LEVEL IN MANY NORTH AND EASTERN ZONES WED
AFTN AND LIKELY A BIT LESS THU AFTN. RH MAY TREND DOWN JUST A BIT
FURTHER ACROSS A GOOD PART OF THE STATE WED AFTN AND IT IS NOT OUT
OF THE QUESTION THAT A FEW SPOTS ACROSS MAINLY EAST CENTRAL AND NE
NM MAY APPROACH OR EVEN BRIEFLY REACH LOW END CRITICAL FIRE WX
CONDITIONS. THIS WILL BE MONITORED CLOSELY FOR ANY DRYING GREATER
THAN CURRENTLY EXPECTED.
THE PREVIOUSLY MODEL FORECASTED SHOWER AND STORM UPTICK DURING AND A
BIT EITHER SIDE OF THE WEEKEND NOW LOOKS TO BE MORE RESTRICTED IN
TIME AND A LITTLE LESS ROBUST THAN PREVIOUSLY ADVERTISED...ESPEC IN
THE NW THIRD TO HALF OF THE STATE. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
256 PM CDT SUN SEP 13 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 256 PM CDT SUN SEP 13 2015
TEMPERATURES THROUGHOUT THE PERIOD AND PRECIP CHANCES LATE MONDAY
NIGHT WILL BE THE MAIN ISSUES FOR THE SHORT TERM.
UPPER FLOW HAS BEEN FAIRLY ZONAL BUT BY MONDAY SHOULD BECOME MORE
SOUTHWESTERLY AS AN UPPER TROUGH DIGS INTO THE WESTERN CONUS. FOR
TONIGHT...A WEAK SHORTWAVE MOVING THROUGH CANADA WILL HELP PUSH
THE SFC LOW CURRENTLY OVER SOUTHERN MANITOBA EASTWARD...BRINGING
THE SFC TROUGH AXIS INTO THE EASTERN CWA. A FAIRLY DECENT COLD
FRONT SHOULD MOVE IN BEHIND THE SFC TROUGH...WITH WINDS SHIFTING
TO THE NORTHWEST BEHIND ALL BUT THE FAR SOUTHEASTERN CWA BY
MORNING. NOT MUCH LOW LEVEL MOISTURE AND MODELS KEEP THE FRONTAL
PASSAGE DRY. HOWEVER...THINK THAT A FEW MORE HIGH AND MID CLOUDS
WILL MOVE INTO AT LEAST PART OF THE CWA. THE SREF PROBABILITIES
SHOW THAT MANY MODELS ARE TRYING TO BREAK OUT SOME FOG ALONG THE
TROUGH AXIS IN OUR EAST CENTRAL COUNTIES. HOWEVER...THE RAP AND
HRRR KEEP THE FOG OUT AND THINK THAT LIGHT WINDS WILL BE BRIEF
ENOUGH TO KEEP FOG FROM FORMING. WILL LEAVE ANY MENTION OUT FOR
NOW.
BY TOMORROW...THE SFC FRONTAL BOUNDARY WILL BE MOSTLY SOUTH OF THE
CWA. TEMPS WILL BE A BIT COOLER THAN TODAY...WITH NEAR 70 IN THE
NORTH TO LOW 80S IN THE SOUTH. MONDAY NIGHT...A SFC LOW WILL
DEEPEN OVER THE MT/ND BORDER. WINDS WILL BEGIN TO SHIFT BACK TO
THE SOUTH AND PICK UP...WITH A WARM FRONT LIFTING NORTH ACROSS THE
CWA OVERNIGHT. THE GFS BREAKS OUT A FAIR AMOUNT OF PRECIP WITH THE
WARM AIR ADVECTION MONDAY NIGHT...BUT IS AN OUTLIER. EVEN THE
BLENDED SOLUTIONS HAVE VERY LITTLE PRECIP SO WILL KEEP IT MOSTLY
DRY MONDAY NIGHT WITH TEMPS IN THE 50S AND 60S WITH SOUTH WINDS
AND WARM AIR MOVING INTO THE REGION.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 256 PM CDT SUN SEP 13 2015
TUESDAY AND WEDNESDAY...MODELS ARE ALL IN FAIRLY GOOD AGREEMENT
ON SOUTHWESTERLY FLOW ALOFT AND SOME WEAK LEAD SHORTWAVES COMING
THROUGH. THE FIRST OF THESE WILL BE TUESDAY...WITH THE SHORTWAVE
MOVING INTO THE WESTERN DAKOTAS DURING THE DAY AND PUSHING THE SFC
TROUGH INTO THE CWA. SOME PRETTY GOOD WARM AIR AND TEMPS WILL GET
INTO THE 80S AGAIN. THE NAM HAS A FAIRLY GOOD AMOUNT OF
INSTABILITY WITH CAPE VALUES NEAR 2000 J/KG ALTHOUGH DEEP LAYER
BULK SHEAR IS ONLY AROUND 30 KTS. GFS IS NOT AS STRONG WITH
INSTABILITY. WILL GO WITH SOME 20-30 POPS FOR THUNDERSTORMS
THURSDAY AFTERNOON AND EVENING BUT NOT CERTAIN ENOUGH FOR ANY
SEVERE MENTION IN THE GRIDS AT THIS POINT. THE SFC LOW WILL MOVE
OFF TO THE EAST AND THE FRONTAL BOUNDARY WILL MOVE THROUGH TUESDAY
NIGHT...ONLY TO COME BACK UP WEDNESDAY AS THE SFC LOW REDEVELOPS
TO OUR WEST. HAVE COOLER TEMPS IN THE NORTH ON WEDNESDAY BUT THE
SOUTH SHOULD STILL BE IN THE 80S...ALONG WITH SOME LOW POPS.
FOR WEDNESDAY NIGHT THROUGH SUNDAY...WILL START OFF THE PERIOD WITH
SOUTHWEST FLOW ALOFT. AN INITIAL WAVE AND ACCOMPANYING SFC LOW LOOK
TO EJECT OUT ON WED NIGHT INTO THU BRINGING CHANCES FOR PCPN. MOST
MODELS SHOW THU AFTERNOON DRY ON THE ND SIDE...BUT GUIDANCE IS
HANGING ONTO SOME LOW CHANCES FOR NOW. ANOTHER WAVE MAY AFFECT THE
FA THU NIGHT INTO FRI. AT THIS POINT GFS/CANADIAN ARE NOT SHOWING
MUCH PCPN WHILE THE ECMWF IS...SO AGAIN WILL MAINTAIN SOME VERY LOW
CHANCES. THEREAFTER FLOW TURNS A BIT MORE ZONAL WITH DRIER WEATHER
FOR SAT AND SUN. TEMPS LOOK A LITTLE COOLER FOR THU/FRI WITH THE
POTENTIAL FOR PCPN THEN WARM UP TOWARD NORMAL BY SAT/SUN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1240 PM CDT SUN SEP 13 2015
NOT EXPECTING MUCH FOR SKY COVER THROUGH THE NEXT 24 HOURS. GUSTY S
TO SSW WINDS WILL DECREASE BY EARLY EVENING. THEN THE CHALLENGE IS
TRYING TO TIME THE WIND SWITCH TO THE NORTH AS A FRONTAL BOUNDARY
SAGS SOUTH LATE TONIGHT INTO EARLY MONDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/GODON
AVIATION...GODON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1222 PM CDT SUN SEP 13 2015
.UPDATE...
ISSUED AT 1205 PM CDT SUN SEP 13 2015
SURFACE LOW PRESSURE WAS LOCATED OVER SOUTHERN MANITOBA WITH A
COLD FRONT EXTENDING SOUTHWEST INTO NORTHEAST MONTANA...ABOUT TO
PUSH INTO NORTHWEST NORTH DAKOTA. AHEAD OF THE FRONT TEMPERATURES
HAVE RISEN INTO THE 70S TO LOWER 80S ACROSS MOST OF WESTERN AND
CENTRAL NORTH DAKOTA. CURRENT TEMPERATURES LOOK REASONABLE SO NO
SIGNIFICANT UPDATES FOR THE AFTERNOON.
UPDATE ISSUED AT 922 AM CDT SUN SEP 13 2015
SUNNY SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS SUNDAY
MORNING. NO CHANGES TO THE GOING FORECAST EXCEPT UPDATING THE
LATEST SENSIBLE WEATHER ELEMENTS. NO CHANGES TO THE CURRENT RED
FLAG WARNING OVER THE SOUTHWEST.
UPDATE ISSUED AT 650 AM CDT SUN SEP 13 2015
BLENDED IN CURRENT CONDITIONS FOR THE UPDATE. THE REMAINDER OF THE
FORECAST IS STILL ON TRACK...WITH A RED FLAG WARNING POSTED ACROSS
PARTS OF THE SOUTHWEST LATE THIS MORNING THROUGH THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN FOCUS FOR THE SHORT TERM IS CRITICAL FIRE CONDITIONS
ACROSS SOUTHWEST NORTH DAKOTA THIS AFTERNOON.
A SURFACE LOW...CURRENTLY OVER SOUTHERN CANADA...WILL PROPAGATE
THROUGH NORTHERN NORTH DAKOTA LATER TODAY...BRINING A COLD FRONT
ALONG WITH IT. AHEAD OF THE LOW AND COLD FRONT...WAA AND
COMPRESSIONAL WARMING WILL LEAD TO TEMPERATURES IN THE UPPER 80S
TO LOW 90S. BREEZY WEST DOWNSLOPING WINDS WILL FURTHER ENHANCE
MIXING AND DRYING OUT OF THE BOUNDARY LAYER. THE RAP AND HRRR
INDICATE VERY HIGH LEVEL MIXING BY THE AFTERNOON WITH A VERY DRY
BOUNDARY LAYER. BASED ON SHORT TERM GUIDANCE INDICATING AFTERNOON
HUMIDITY AROUND 15 PERCENT...WINDS AROUND 20 MPH...AND RELATIVELY
DRY FUELS...DECIDED TO UPGRADE FIRE WEATHER WATCH TO A RED FLAG
WARNING. THE LATEST SPC FIRE WEATHER OUTLOOKS WILL ALSO INDICATE
AN ENHANCED THREAT FOR CRITICAL FIRE CONDITIONS ACROSS SOUTHWEST
NORTH DAKOTA. AS THE LOW PASSES BY THIS EVENING CONDITIONS WILL
RAPIDLY IMPROVE. WINDS WILL DIMINISH AROUND SUNSET AND HUMIDITY
VALUES WILL QUICKLY REBOUND. FOR MORE INFORMATION SEE THE FIRE
WEATHER DISCUSSION BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN CONCERN IN THE LONG TERM PERIOD WILL BE PERIODIC CHANCES
FOR SHOWERS / THUNDERSTORMS. THE LONG TERM PERIOD WILL FEATURE
WEST / SOUTHWEST FLOW ALOFT WITH WAVES RIPPLING THROUGH THE UPPER
LEVEL FLOW. TIMING OF THE WEAKER / MORE SUBTLE WAVES EARLY IN THE
PERIOD IS DIFFICULT...BUT THERE DOES APPEAR TO BE SOME AGREEMENT
THAT A SURFACE LOW AND COLD FRONT WILL MOVE ACROSS THE REGION
TUESDAY INTO TUESDAY NIGHT. SPC HAS THE ENTIRE FORECAST AREA IN
THEIR THUNDERSTORM OUTLOOK FOR TUESDAY...WITH EVEN A MARGINAL RISK
OF SEVERE THUNDERSTORMS CATCHING A SMALL SLIVER OF THE FORECAST
AREA TOWARDS THE TURTLE MOUNTAINS. CONFIDENCE IN THE OVERALL
THUNDERSTORM CHANCES ON TUESDAY IS NOT VERY HIGH WITH MOST MODEL
SOLUTIONS KEEPING THE BETTER CHANCES IN CANADA. WILL CONTINUE TO
CARRY SMALL POPS TUESDAY INTO TUESDAY NIGHT...WITH THE HIGHER
CHANCES IN THE NORTHWEST.
THE STRONGEST H5 WAVE APPEARS TO MOVE ACROSS THE NORTHERN PLAINS
WEDNESDAY AND THURSDAY. THE MODEL BLEND PICKS UP ON THIS AND STILL
HAS LIKELY POPS ACROSS PARTS OF WESTERN AND CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT. INTERESTINGLY...THE 13.00Z ECMWF HAS BACKED OFF ON
THE RAIN CHANCES FOR WEDNESDAY NIGHT...AND BRINGS ACROSS A STRONGER
H5 WAVE THURSDAY INTO FRIDAY. FOR NOW...WILL FOLLOW THE MODEL
CONSENSUS SINCE TIMING THIS FAR IN ADVANCE CAN EASILY CHANGE.
INSTABILITY BECOMES VERY LIMITED BY THURSDAY NIGHT...SO HAVE REMOVED
THUNDER FROM THURSDAY NIGHT AND BEYOND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1205 PM CDT SUN SEP 13 2015
A COLD FRONT WILL MOVE INTO NORTHWEST NORTH DAKOTA THIS AFTERNOON
AND TRACK ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA THIS
EVENING. BEHIND THE COLD FRONT...EXTENSIVE CLOUD COVER OVER
SASKATCHEWAN AND MANITOBA WILL BEGIN TO DROP SOUTH TONIGHT AND IS
EXPECTED TO COVER THE FORECAST AREA BY MONDAY MORNING. THERE ARE
SOME BIG DIFFERENCES BETWEEN GFS/NAM IN THE EXTENT OF LOWER CLOUD
COVER MONDAY MORNING. BUT AS OUR SURFACE FLOW SHIFTS EASTWARD
BEHIND THE FRONT...EXPECT INCREASING LOW LEVEL MOISTURE OVER THE
AREA. WILL NOT GO AS PESSIMISTIC AS THE NAM AT THIS TIME BUT WILL
BRING IN A SCATTERED LAYER OF MVFR CLOUDS WITH LOWER VFR CEILINGS
MONDAY MORNING. DO EXPECT CEILINGS TO LIFT/DISSIPATE LATE MORNING
INTO MONDAY AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 358 AM CDT SUN SEP 13 2015
A COLD FRONT AND SURFACE LOW PRESSURE WILL MOVE INTO NORTHERN NORTH
DAKOTA THIS AFTERNOON. SOUTHWEST NORTH DAKOTA WILL BE IN THE WARM
SECTOR MOST OF THE DAY WITH HIGH TEMPERATURES IN THE MIDDLE TO
UPPER 80S AND SOUTHWEST WINDS SHIFTING WESTERLY AHEAD OF THE
APPROACHING COLD FRONT. WITH AFTERNOON DEWPOINTS AROUND 40
DEGREES...MINIMUM HUMIDITIES ARE EXPECTED TO BE IN THE 15 TO 20
PERCENT RANGE SUNDAY AFTERNOON. THE RAP/NAM/HRRR FORECAST SOUNDING
DATA INDICATE AMPLE MIXING OF THE BOUNDARY LAYER AND 15 TO 20 MPH
WINDS WITH GUSTS TO AROUND 25 MPH MAXIMIZED DURING THE EARLY
AFTERNOON...THEN WINDS START TO DIMINISH BY THE EARLY EVENING
HOURS. SOME MODEL GUIDANCE IS SUGGESTING THAT CONDITIONS COULD
POTENTIALLY BE DRIER WITH EVEN HIGHER WINDS. THE LATEST FROM FIRE
OFFICIALS IS THAT THE SOUTHWEST CONTINUES TO CURE AND WOULD CARRY
FIRE FAIRLY EASILY. THEREFORE...A RED FLAG WARNING HAS BEEN
ISSUED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR NDZ031>033-040-
041-043-044.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...CK
AVIATION...TWH
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
926 AM CDT SUN SEP 13 2015
.UPDATE...
ISSUED AT 922 AM CDT SUN SEP 13 2015
SUNNY SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS SUNDAY
MORNING. NO CHANGES TO THE GOING FORECAST EXCEPT UPDATING THE
LATEST SENSIBLE WEATHER ELEMENTS. NO CHANGES TO THE CURRENT RED
FLAG WARNING OVER THE SOUTHWEST.
UPDATE ISSUED AT 650 AM CDT SUN SEP 13 2015
BLENDED IN CURRENT CONDITIONS FOR THE UPDATE. THE REMAINDER OF THE
FORECAST IS STILL ON TRACK...WITH A RED FLAG WARNING POSTED ACROSS
PARTS OF THE SOUTHWEST LATE THIS MORNING THROUGH THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN FOCUS FOR THE SHORT TERM IS CRITICAL FIRE CONDITIONS
ACROSS SOUTHWEST NORTH DAKOTA THIS AFTERNOON.
A SURFACE LOW...CURRENTLY OVER SOUTHERN CANADA...WILL PROPAGATE
THROUGH NORTHERN NORTH DAKOTA LATER TODAY...BRINING A COLD FRONT
ALONG WITH IT. AHEAD OF THE LOW AND COLD FRONT...WAA AND
COMPRESSIONAL WARMING WILL LEAD TO TEMPERATURES IN THE UPPER 80S
TO LOW 90S. BREEZY WEST DOWNSLOPING WINDS WILL FURTHER ENHANCE
MIXING AND DRYING OUT OF THE BOUNDARY LAYER. THE RAP AND HRRR
INDICATE VERY HIGH LEVEL MIXING BY THE AFTERNOON WITH A VERY DRY
BOUNDARY LAYER. BASED ON SHORT TERM GUIDANCE INDICATING AFTERNOON
HUMIDITY AROUND 15 PERCENT...WINDS AROUND 20 MPH...AND RELATIVELY
DRY FUELS...DECIDED TO UPGRADE FIRE WEATHER WATCH TO A RED FLAG
WARNING. THE LATEST SPC FIRE WEATHER OUTLOOKS WILL ALSO INDICATE
AN ENHANCED THREAT FOR CRITICAL FIRE CONDITIONS ACROSS SOUTHWEST
NORTH DAKOTA. AS THE LOW PASSES BY THIS EVENING CONDITIONS WILL
RAPIDLY IMPROVE. WINDS WILL DIMINISH AROUND SUNSET AND HUMIDITY
VALUES WILL QUICKLY REBOUND. FOR MORE INFORMATION SEE THE FIRE
WEATHER DISCUSSION BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN CONCERN IN THE LONG TERM PERIOD WILL BE PERIODIC CHANCES
FOR SHOWERS / THUNDERSTORMS. THE LONG TERM PERIOD WILL FEATURE
WEST / SOUTHWEST FLOW ALOFT WITH WAVES RIPPLING THROUGH THE UPPER
LEVEL FLOW. TIMING OF THE WEAKER / MORE SUBTLE WAVES EARLY IN THE
PERIOD IS DIFFICULT...BUT THERE DOES APPEAR TO BE SOME AGREEMENT
THAT A SURFACE LOW AND COLD FRONT WILL MOVE ACROSS THE REGION
TUESDAY INTO TUESDAY NIGHT. SPC HAS THE ENTIRE FORECAST AREA IN
THEIR THUNDERSTORM OUTLOOK FOR TUESDAY...WITH EVEN A MARGINAL RISK
OF SEVERE THUNDERSTORMS CATCHING A SMALL SLIVER OF THE FORECAST
AREA TOWARDS THE TURTLE MOUNTAINS. CONFIDENCE IN THE OVERALL
THUNDERSTORM CHANCES ON TUESDAY IS NOT VERY HIGH WITH MOST MODEL
SOLUTIONS KEEPING THE BETTER CHANCES IN CANADA. WILL CONTINUE TO
CARRY SMALL POPS TUESDAY INTO TUESDAY NIGHT...WITH THE HIGHER
CHANCES IN THE NORTHWEST.
THE STRONGEST H5 WAVE APPEARS TO MOVE ACROSS THE NORTHERN PLAINS
WEDNESDAY AND THURSDAY. THE MODEL BLEND PICKS UP ON THIS AND STILL
HAS LIKELY POPS ACROSS PARTS OF WESTERN AND CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT. INTERESTINGLY...THE 13.00Z ECMWF HAS BACKED OFF ON
THE RAIN CHANCES FOR WEDNESDAY NIGHT...AND BRINGS ACROSS A STRONGER
H5 WAVE THURSDAY INTO FRIDAY. FOR NOW...WILL FOLLOW THE MODEL
CONSENSUS SINCE TIMING THIS FAR IN ADVANCE CAN EASILY CHANGE.
INSTABILITY BECOMES VERY LIMITED BY THURSDAY NIGHT...SO HAVE REMOVED
THUNDER FROM THURSDAY NIGHT AND BEYOND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 922 AM CDT SUN SEP 13 2015
A QUIET 12Z TAF PERIOD IS EXPECTED WITH VFR CONDITIONS FORECAST.
WINDS WILL INCREASE BY LATE MORNING / EARLY AFTERNOON FROM THE
WEST TO SOUTHWEST...BUT WILL DIMINISH AGAIN THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 358 AM CDT SUN SEP 13 2015
A COLD FRONT AND SURFACE LOW PRESSURE WILL MOVE INTO NORTHERN NORTH
DAKOTA THIS AFTERNOON. SOUTHWEST NORTH DAKOTA WILL BE IN THE WARM
SECTOR MOST OF THE DAY WITH HIGH TEMPERATURES IN THE MIDDLE TO
UPPER 80S AND SOUTHWEST WINDS SHIFTING WESTERLY AHEAD OF THE
APPROACHING COLD FRONT. WITH AFTERNOON DEWPOINTS AROUND 40
DEGREES...MINIMUM HUMIDITIES ARE EXPECTED TO BE IN THE 15 TO 20
PERCENT RANGE SUNDAY AFTERNOON. THE RAP/NAM/HRRR FORECAST SOUNDING
DATA INDICATE AMPLE MIXING OF THE BOUNDARY LAYER AND 15 TO 20 MPH
WINDS WITH GUSTS TO AROUND 25 MPH MAXIMIZED DURING THE EARLY
AFTERNOON...THEN WINDS START TO DIMINISH BY THE EARLY EVENING
HOURS. SOME MODEL GUIDANCE IS SUGGESTING THAT CONDITIONS COULD
POTENTIALLY BE DRIER WITH EVEN HIGHER WINDS. THE LATEST FROM FIRE
OFFICIALS IS THAT THE SOUTHWEST CONTINUES TO CURE AND WOULD CARRY
FIRE FAIRLY EASILY. THEREFORE...A RED FLAG WARNING HAS BEEN
ISSUED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR NDZ031>033-040-
041-043-044.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...CK
AVIATION...TWH
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
651 AM CDT SUN SEP 13 2015
.UPDATE...
ISSUED AT 650 AM CDT SUN SEP 13 2015
BLENDED IN CURRENT CONDITIONS FOR THE UPDATE. THE REMAINDER OF THE
FORECAST IS STILL ON TRACK...WITH A RED FLAG WARNING POSTED ACROSS
PARTS OF THE SOUTHWEST LATE THIS MORNING THROUGH THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN FOCUS FOR THE SHORT TERM IS CRITICAL FIRE CONDITIONS
ACROSS SOUTHWEST NORTH DAKOTA THIS AFTERNOON.
A SURFACE LOW...CURRENTLY OVER SOUTHERN CANADA...WILL PROPAGATE
THROUGH NORTHERN NORTH DAKOTA LATER TODAY...BRINING A COLD FRONT
ALONG WITH IT. AHEAD OF THE LOW AND COLD FRONT...WAA AND
COMPRESSIONAL WARMING WILL LEAD TO TEMPERATURES IN THE UPPER 80S
TO LOW 90S. BREEZY WEST DOWNSLOPING WINDS WILL FURTHER ENHANCE
MIXING AND DRYING OUT OF THE BOUNDARY LAYER. THE RAP AND HRRR
INDICATE VERY HIGH LEVEL MIXING BY THE AFTERNOON WITH A VERY DRY
BOUNDARY LAYER. BASED ON SHORT TERM GUIDANCE INDICATING AFTERNOON
HUMIDITY AROUND 15 PERCENT...WINDS AROUND 20 MPH...AND RELATIVELY
DRY FUELS...DECIDED TO UPGRADE FIRE WEATHER WATCH TO A RED FLAG
WARNING. THE LATEST SPC FIRE WEATHER OUTLOOKS WILL ALSO INDICATE
AN ENHANCED THREAT FOR CRITICAL FIRE CONDITIONS ACROSS SOUTHWEST
NORTH DAKOTA. AS THE LOW PASSES BY THIS EVENING CONDITIONS WILL
RAPIDLY IMPROVE. WINDS WILL DIMINISH AROUND SUNSET AND HUMIDITY
VALUES WILL QUICKLY REBOUND. FOR MORE INFORMATION SEE THE FIRE
WEATHER DISCUSSION BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN CONCERN IN THE LONG TERM PERIOD WILL BE PERIODIC CHANCES
FOR SHOWERS / THUNDERSTORMS. THE LONG TERM PERIOD WILL FEATURE
WEST / SOUTHWEST FLOW ALOFT WITH WAVES RIPPLING THROUGH THE UPPER
LEVEL FLOW. TIMING OF THE WEAKER / MORE SUBTLE WAVES EARLY IN THE
PERIOD IS DIFFICULT...BUT THERE DOES APPEAR TO BE SOME AGREEMENT
THAT A SURFACE LOW AND COLD FRONT WILL MOVE ACROSS THE REGION
TUESDAY INTO TUESDAY NIGHT. SPC HAS THE ENTIRE FORECAST AREA IN
THEIR THUNDERSTORM OUTLOOK FOR TUESDAY...WITH EVEN A MARGINAL RISK
OF SEVERE THUNDERSTORMS CATCHING A SMALL SLIVER OF THE FORECAST
AREA TOWARDS THE TURTLE MOUNTAINS. CONFIDENCE IN THE OVERALL
THUNDERSTORM CHANCES ON TUESDAY IS NOT VERY HIGH WITH MOST MODEL
SOLUTIONS KEEPING THE BETTER CHANCES IN CANADA. WILL CONTINUE TO
CARRY SMALL POPS TUESDAY INTO TUESDAY NIGHT...WITH THE HIGHER
CHANCES IN THE NORTHWEST.
THE STRONGEST H5 WAVE APPEARS TO MOVE ACROSS THE NORTHERN PLAINS
WEDNESDAY AND THURSDAY. THE MODEL BLEND PICKS UP ON THIS AND STILL
HAS LIKELY POPS ACROSS PARTS OF WESTERN AND CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT. INTERESTINGLY...THE 13.00Z ECMWF HAS BACKED OFF ON
THE RAIN CHANCES FOR WEDNESDAY NIGHT...AND BRINGS ACROSS A STRONGER
H5 WAVE THURSDAY INTO FRIDAY. FOR NOW...WILL FOLLOW THE MODEL
CONSENSUS SINCE TIMING THIS FAR IN ADVANCE CAN EASILY CHANGE.
INSTABILITY BECOMES VERY LIMITED BY THURSDAY NIGHT...SO HAVE REMOVED
THUNDER FROM THURSDAY NIGHT AND BEYOND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CDT SUN SEP 13 2015
A QUIET 12Z TAF PERIOD IS EXPECTED WITH VFR CONDITIONS FORECAST.
WINDS WILL INCREASE BY LATE MORNING / EARLY AFTERNOON FROM THE
WEST TO SOUTHWEST...BUT WILL DIMINISH AGAIN THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 358 AM CDT SUN SEP 13 2015
A COLD FRONT AND SURFACE LOW PRESSURE WILL MOVE INTO NORTHERN NORTH
DAKOTA THIS AFTERNOON. SOUTHWEST NORTH DAKOTA WILL BE IN THE WARM
SECTOR MOST OF THE DAY WITH HIGH TEMPERATURES IN THE MIDDLE TO
UPPER 80S AND SOUTHWEST WINDS SHIFTING WESTERLY AHEAD OF THE
APPROACHING COLD FRONT. WITH AFTERNOON DEWPOINTS AROUND 40
DEGREES...MINIMUM HUMIDITIES ARE EXPECTED TO BE IN THE 15 TO 20
PERCENT RANGE SUNDAY AFTERNOON. THE RAP/NAM/HRRR FORECAST SOUNDING
DATA INDICATE AMPLE MIXING OF THE BOUNDARY LAYER AND 15 TO 20 MPH
WINDS WITH GUSTS TO AROUND 25 MPH MAXIMIZED DURING THE EARLY
AFTERNOON...THEN WINDS START TO DIMINISH BY THE EARLY EVENING
HOURS. SOME MODEL GUIDANCE IS SUGGESTING THAT CONDITIONS COULD
POTENTIALLY BE DRIER WITH EVEN HIGHER WINDS. THE LATEST FROM FIRE
OFFICIALS IS THAT THE SOUTHWEST CONTINUES TO CURE AND WOULD CARRY
FIRE FAIRLY EASILY. THEREFORE...A RED FLAG WARNING HAS BEEN
ISSUED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 6 PM MDT THIS
EVENING FOR NDZ031>033-040-041-043-044.
&&
$$
UPDATE...CK
SHORT TERM...AJ
LONG TERM...CK
AVIATION...CK
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
359 AM CDT SUN SEP 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN FOCUS FOR THE SHORT TERM IS CRITICAL FIRE CONDITIONS
ACROSS SOUTHWEST NORTH DAKOTA THIS AFTERNOON.
A SURFACE LOW...CURRENTLY OVER SOUTHERN CANADA...WILL PROPAGATE
THROUGH NORTHERN NORTH DAKOTA LATER TODAY...BRINING A COLD FRONT
ALONG WITH IT. AHEAD OF THE LOW AND COLD FRONT...WAA AND
COMPRESSIONAL WARMING WILL LEAD TO TEMPERATURES IN THE UPPER 80S
TO LOW 90S. BREEZY WEST DOWNSLOPING WINDS WILL FURTHER ENHANCE
MIXING AND DRYING OUT OF THE BOUNDARY LAYER. THE RAP AND HRRR
INDICATE VERY HIGH LEVEL MIXING BY THE AFTERNOON WITH A VERY DRY
BOUNDARY LAYER. BASED ON SHORT TERM GUIDANCE INDICATING AFTERNOON
HUMIDITY AROUND 15 PERCENT...WINDS AROUND 20 MPH...AND RELATIVELY
DRY FUELS...DECIDED TO UPGRADE FIRE WEATHER WATCH TO A RED FLAG
WARNING. THE LATEST SPC FIRE WEATHER OUTLOOKS WILL ALSO INDICATE
AN ENHANCED THREAT FOR CRITICAL FIRE CONDITIONS ACROSS SOUTHWEST
NORTH DAKOTA. AS THE LOW PASSES BY THIS EVENING CONDITIONS WILL
RAPIDLY IMPROVE. WINDS WILL DIMINISH AROUND SUNSET AND HUMIDITY
VALUES WILL QUICKLY REBOUND. FOR MORE INFORMATION SEE THE FIRE
WEATHER DISCUSSION BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN SEP 13 2015
THE MAIN CONCERN IN THE LONG TERM PERIOD WILL BE PERIODIC CHANCES
FOR SHOWERS / THUNDERSTORMS. THE LONG TERM PERIOD WILL FEATURE
WEST / SOUTHWEST FLOW ALOFT WITH WAVES RIPPLING THROUGH THE UPPER
LEVEL FLOW. TIMING OF THE WEAKER / MORE SUBTLE WAVES EARLY IN THE
PERIOD IS DIFFICULT...BUT THERE DOES APPEAR TO BE SOME AGREEMENT
THAT A SURFACE LOW AND COLD FRONT WILL MOVE ACROSS THE REGION
TUESDAY INTO TUESDAY NIGHT. SPC HAS THE ENTIRE FORECAST AREA IN
THEIR THUNDERSTORM OUTLOOK FOR TUESDAY...WITH EVEN A MARGINAL RISK
OF SEVERE THUNDERSTORMS CATCHING A SMALL SLIVER OF THE FORECAST
AREA TOWARDS THE TURTLE MOUNTAINS. CONFIDENCE IN THE OVERALL
THUNDERSTORM CHANCES ON TUESDAY IS NOT VERY HIGH WITH MOST MODEL
SOLUTIONS KEEPING THE BETTER CHANCES IN CANADA. WILL CONTINUE TO
CARRY SMALL POPS TUESDAY INTO TUESDAY NIGHT...WITH THE HIGHER
CHANCES IN THE NORTHWEST.
THE STRONGEST H5 WAVE APPEARS TO MOVE ACROSS THE NORTHERN PLAINS
WEDNESDAY AND THURSDAY. THE MODEL BLEND PICKS UP ON THIS AND STILL
HAS LIKELY POPS ACROSS PARTS OF WESTERN AND CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT. INTERESTINGLY...THE 13.00Z ECMWF HAS BACKED OFF ON
THE RAIN CHANCES FOR WEDNESDAY NIGHT...AND BRINGS ACROSS A STRONGER
H5 WAVE THURSDAY INTO FRIDAY. FOR NOW...WILL FOLLOW THE MODEL
CONSENSUS SINCE TIMING THIS FAR IN ADVANCE CAN EASILY CHANGE.
INSTABILITY BECOMES VERY LIMITED BY THURSDAY NIGHT...SO HAVE REMOVED
THUNDER FROM THURSDAY NIGHT AND BEYOND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 358 AM CDT SUN SEP 13 2015
VFR CONDITIONS AT ALL TAF SITES THROUGH THE PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 358 AM CDT SUN SEP 13 2015
A COLD FRONT AND SURFACE LOW PRESSURE WILL MOVE INTO NORTHERN NORTH
DAKOTA THIS AFTERNOON. SOUTHWEST NORTH DAKOTA WILL BE IN THE WARM
SECTOR MOST OF THE DAY WITH HIGH TEMPERATURES IN THE MIDDLE TO
UPPER 80S AND SOUTHWEST WINDS SHIFTING WESTERLY AHEAD OF THE
APPROACHING COLD FRONT. WITH AFTERNOON DEWPOINTS AROUND 40
DEGREES...MINIMUM HUMIDITIES ARE EXPECTED TO BE IN THE 15 TO 20
PERCENT RANGE SUNDAY AFTERNOON. THE RAP/NAM/HRRR FORECAST SOUNDING
DATA INDICATE AMPLE MIXING OF THE BOUNDARY LAYER AND 15 TO 20 MPH
WINDS WITH GUSTS TO AROUND 25 MPH MAXIMIZED DURING THE EARLY
AFTERNOON...THEN WINDS START TO DIMINISH BY THE EARLY EVENING
HOURS. SOME MODEL GUIDANCE IS SUGGESTING THAT CONDITIONS COULD
POTENTIALLY BE DRIER WITH EVEN HIGHER WINDS. THE LATEST FROM FIRE
OFFICIALS IS THAT THE SOUTHWEST CONTINUES TO CURE AND WOULD CARRY
FIRE FAIRLY EASILY. THEREFORE...A RED FLAG WARNING HAS BEEN
ISSUED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 6 PM MDT THIS
EVENING FOR NDZ031>033-040-041-043-044.
&&
$$
SHORT TERM...AJ
LONG TERM...CK
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
610 PM EDT SUN SEP 13 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXPAND ACROSS THE SOUTHERN GREAT LAKES TONIGHT.
THE HIGH WILL BUILD TO THE EAST COAST AND CONTINUE TO INFLUENCE THE
WEATHER ACROSS THE EASTERN GREAT LAKES INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPPER LEVEL TROUGH REMAINS IN PLACE OVER THE EASTERN GREAT LAKES
WITH MOISTURE SPREADING SOUTH OUT OF CANADA ACROSS EASTERN LAKE
ERIE. CURRENT RADAR SHOW SOME SHRA OVER EASTERN PARTS OF ERIE AND
CRAWFORD COUNTIES. EXPECT THIS TO CONTINUE UNTIL LATE EVENING THEN
THIS AREA OF SHRA SHOULD START SHIFTING OFF TO THE EAST AS THE UPPER
TROUGH STARTS TO MOVE AWAY FASTER. WILL CONTINUE TO CARRY SCATTERED
SHOWERS THIS EVENING WITH POPS TAPERING DOWN TO JUST A SLIGHT CHANCE
ALONG THE SHORELINE BY MORNING.
THE HRRR ALSO DEVELOP A FEW LIGHT SHRA/SPRINKLES AROUND CLE BY LATE
EVENING WHERE LOW LEVEL CONVERGENCE DEVELOPS. WILL STAY WITH
PREVIOUS THINKING THAT AIRMASS IS TOO DRY FOR ANYTHING TO DEVELOP TO
THE POINT OF GETTING ANYTHING OF NOTE TO THE GROUND THAT FAR WEST.
ELSEWHERE THE DIURNAL CU FIELD WILL CONTINUE TO DISSIPATE THRU
SUNSET WITH MOSTLY CLEAR SKIES AFTER 00Z.
THE CLEARED SKIES AND LIGHT WINDS SHOULD ALLOW INLAND TEMPS TO FALL
INTO THE LOW TO MID 40S WHILE THE LAKESHORE HOLDS UP IN A 50 TO 55
RANGE FROM CLEVELAND EAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
A PROLONGED STRETCH OF DRY WEATHER IS IN STORE AS THE LARGE AREA OF
HIGH PRESSURE OVER THE MISSISSIPPI VALLEY SETS UP ALONG THE MID-
ATLANTIC. FAIRLY STRONG WARM ADVECTION AND LOTS OF SUN ON MONDAY
WILL BOOST HIGHS BY ABOUT 10 DEGREES FROM TODAYS HIGHS.
TEMPERATURES WILL STILL BE A TOUCH BELOW NORMAL ON MONDAY...WITH A
GRADUAL WARMING TREND CONTINUING THIS WEEK AS THE RIDGE BUILDS
ALOFT. DRY WEATHER WILL CONTINUE THROUGH THE SHORT TERM WITH A
LARGE DIURNAL SPREAD AND COOL NIGHTS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
UPPER LEVEL RIDGE WILL DOMINATE THE FORECAST AREA THURSDAY INTO
FRIDAY. THE RIDGE WILL AMPLIFY WITH TIME AS UPPER LEVEL TROUGH DIGS
EAST INTO THE CENTRAL PORTIONS OF THE UNITED STATES. AS THE UPPER
LEVEL TROUGH SWINGS EAST ACROSS THE GREAT LAKES AND BECOMES
NEGATIVELY TILTED. SURFACE LOW PRESSURE WILL FORM ALONG A COLD FRONT
AND MOVE NORTHEAST AND DEEPEN WEST OF MAINE. THE COLD FRONT WILL
PUSH THROUGH THE AREA ON SATURDAY BRINGING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS TO THE AREA. ONCE FRONT PUSHES EAST...DRIER AIR
ASSOCIATED WITH HIGH PRESSURE WILL PUSH INTO THE REGION FOR THE REST
OF THE WEEKEND. UPPER LEVEL PATTERN TRENDS TOWARD ZONAL FLOW INTO
NEXT WEEK.
TEMPERATURES WILL REBOUND INTO THE 70S AND 80S DURING THE EXTENDED
PERIODS AHEAD OF THE COLD FRONT. ONCE FRONT MOVES EAST OF THE AREA
SOME WEAK COLD AIR ADVECTION WILL TAKE PLACE SATURDAY AND SATURDAY
NIGHT. ANOTHER REBOUND WILL TAKE PLACE SUNDAY AS FLOW BECOMES MORE
SOUTHERLY INTO SUNDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
CONDITIONS ARE GRADUALLY IMPROVING OVER THE FORECAST AREA AT THIS
TIME. SHOWERS OVER THE EXTREME EAST ARE GRADUALLY DISSIPATING AS
DRIER AIR PUSHES INTO THE REGION IN RESPONSE TO THE HIGH PRESSURE
MOVING EAST. A MULTI LAKE BAND OF SHOWERS EXTENDS FROM LAKE HURON
INTO NORTHEAST OHIO WILL GRADUALLY SHIFT EAST TOWARD ERIE AND THEN
DISSIPATE. SO WILL MENTION A TEMPO FOR SOME SCATTERED SHOWERS THIS
AFTERNOON AT ERIE. ELSEWHERE...EXPECTING CLOUDS TO DISSIPATE
OVERNIGHT AND GO CLEAR. WINDS DIMINISHING AS WELL AND SHIFTING TO
SOUTHWEST TOMORROW MORNING.
OUTLOOK...VFR.
&&
.MARINE...
WILL KEEP SMALL CRAFT ADVISORY GOING FROM LORAIN COUNTY EAST
THROUGH 8 AM TOMORROW MORNING. WINDS WILL GRADUALLY SHIFT AROUND
TO A WESTERLY DIRECTION OVERNIGHT BUT REMAIN UP THROUGH THE NIGHT.
EXPECTING WINDS TO DIMINISH SLIGHTLY ON MONDAY OVER THE WEST AND
MAY NEED TO CONTINUE ADVISORY IN THE EAST ON MONDAY. WINDS FINALLY
GO LIGHT AND VARIABLE TUESDAY NIGHT AND REMAINS FAIRLY LIGHT
THROUGH THURSDAY. WINDS INCREASE AGAIN THURSDAY NIGHT INTO FRIDAY
WELL AHEAD OF THE NEXT COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...BEACH HAZARDS STATEMENT THROUGH MONDAY MORNING FOR OHZ010>012-
089.
PA...BEACH HAZARDS STATEMENT THROUGH MONDAY MORNING FOR PAZ001.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LEZ145>149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/ADAMS
SHORT TERM...KEC
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
356 PM EDT SUN SEP 13 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXPAND ACROSS THE SOUTHERN GREAT LAKES TONIGHT.
THE HIGH WILL BUILD TO THE EAST COAST AND CONTINUE TO INFLUENCE THE
WEATHER ACROSS THE EASTERN GREAT LAKES INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPPER LEVEL TROUGH REMAINS IN PLACE OVER THE EASTERN GREAT LAKES
WITH MOISTURE SPREADING SOUTH OUT OF CANADA ACROSS EASTERN LAKE
ERIE. THE KBUF RADAR SHOWS SHOWERS INCREASING THIS AFTERNOON
UPSTREAM TO THE NORTH. THE HRRR AND NAM DNG ARE FAIRLY AGRESSIVE
WITH SHOWERS IN ERIE/CRAWFORD COUNTIES THIS EVENING ALTHOUGH
EXPECTING MOST OF THE ACTIVITY IN THE EASTERN PORTIONS OF THE
COUNTY. THE SURFACE TROUGH EXTENDING FROM LOW PRESSURE NORTH OF
LAKE ONTARIO IS EXPECTED TO PUSH ONSHORE THIS EVENING AND THAT
WILL HELP TO ENHANCE CONVERGENCE ALONG THE SHORELINE. WILL CARRY
SCATTERED SHOWERS FOR A FEW HOURS THIS EVENING WITH POPS TAPERING
DOWN TO JUST A SLIGHT CHANCE ALONG THE SHORELINE BY MORNING.
ELSEWHERE A DIURNALLY ENHANCED CU FIELD IS IN PLACE. THESE CLOUDS
WILL LARGELY DISSIPATE THIS EVENING WITH SKIES CLEARING. TEMPERATURES
WILL GENERALLY FALL TO THE MID 40S...EXCEPT CLOSER TO 50 ALONG THE
LAKESHORE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
A PROLONGED STRETCH OF DRY WEATHER IS IN STORE AS THE LARGE AREA OF
HIGH PRESSURE OVER THE MISSISSIPPI VALLEY SETS UP ALONG THE MID-
ATLANTIC. FAIRLY STRONG WARM ADVECTION AND LOTS OF SUN ON MONDAY
WILL BOOST HIGHS BY ABOUT 10 DEGREES FROM TODAYS HIGHS.
TEMPERATURES WILL STILL BE A TOUCH BELOW NORMAL ON MONDAY...WITH A
GRADUAL WARMING TREND CONTINUING THIS WEEK AS THE RIDGE BUILDS
ALOFT. DRY WEATHER WILL CONTINUE THROUGH THE SHORT TERM WITH A
LARGE DIURNAL SPREAD AND COOL NIGHTS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
UPPER LEVEL RIDGE WILL DOMINATE THE FORECAST AREA THURSDAY INTO
FRIDAY. THE RIDGE WILL AMPLIFY WITH TIME AS UPPER LEVEL TROUGH DIGS
EAST INTO THE CENTRAL PORTIONS OF THE UNITED STATES. AS THE UPPER
LEVEL TROUGH SWINGS EAST ACROSS THE GREAT LAKES AND BECOMES
NEGATIVELY TILTED. SURFACE LOW PRESSURE WILL FORM ALONG A COLD FRONT
AND MOVE NORTHEAST AND DEEPEN WEST OF MAINE. THE COLD FRONT WILL
PUSH THROUGH THE AREA ON SATURDAY BRINGING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS TO THE AREA. ONCE FRONT PUSHES EAST...DRIER AIR
ASSOCIATED WITH HIGH PRESSURE WILL PUSH INTO THE REGION FOR THE REST
OF THE WEEKEND. UPPER LEVEL PATTERN TRENDS TOWARD ZONAL FLOW INTO
NEXT WEEK.
TEMPERATURES WILL REBOUND INTO THE 70S AND 80S DURING THE EXTENDED
PERIODS AHEAD OF THE COLD FRONT. ONCE FRONT MOVES EAST OF THE AREA
SOME WEAK COLD AIR ADVECTION WILL TAKE PLACE SATURDAY AND SATURDAY
NIGHT. ANOTHER REBOUND WILL TAKE PLACE SUNDAY AS FLOW BECOMES MORE
SOUTHERLY INTO SUNDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
CONDITIONS ARE GRADUALLY IMPROVING OVER THE FORECAST AREA AT THIS
TIME. SHOWERS OVER THE EXTREME EAST ARE GRADUALLY DISSIPATING AS
DRIER AIR PUSHES INTO THE REGION IN RESPONSE TO THE HIGH PRESSURE
MOVING EAST. A MULTI LAKE BAND OF SHOWERS EXTENDS FROM LAKE HURON
INTO NORTHEAST OHIO WILL GRADUALLY SHIFT EAST TOWARD ERIE AND THEN
DISSIPATE. SO WILL MENTION A TEMPO FOR SOME SCATTERED SHOWERS THIS
AFTERNOON AT ERIE. ELSEWHERE...EXPECTING CLOUDS TO DISSIPATE
OVERNIGHT AND GO CLEAR. WINDS DIMINISHING AS WELL AND SHIFTING TO
SOUTHWEST TOMORROW MORNING.
OUTLOOK...VFR.
&&
.MARINE...
WILL KEEP SMALL CRAFT ADVISORY GOING FROM LORAIN COUNTY EAST
THROUGH 8 AM TOMORROW MORNING. WINDS WILL GRADUALLY SHIFT AROUND
TO A WESTERLY DIRECTION OVERNIGHT BUT REMAIN UP THROUGH THE NIGHT.
EXPECTING WINDS TO DIMINISH SLIGHTLY ON MONDAY OVER THE WEST AND
MAY NEED TO CONTINUE ADVISORY IN THE EAST ON MONDAY. WINDS FINALLY
GO LIGHT AND VARIABLE TUESDAY NIGHT AND REMAINS FAIRLY LIGHT
THROUGH THURSDAY. WINDS INCREASE AGAIN THURSDAY NIGHT INTO FRIDAY
WELL AHEAD OF THE NEXT COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...BEACH HAZARDS STATEMENT THROUGH MONDAY MORNING FOR OHZ010>012-
089.
PA...BEACH HAZARDS STATEMENT THROUGH MONDAY MORNING FOR PAZ001.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LEZ145>149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1233 AM CDT SUN SEP 13 2015
.DISCUSSION...SEE AVIATION DISCUSSION BELOW FOR THE 06Z TAFS.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE TAF
PERIOD WITH THE EXCEPTION OF POSSIBLE FOG TOWARD SUNRISE...MAINLY
FOR ALI AND TO A LESSER EXTENT VCT. DUE TO LIGHT WINDS AND A DRY
AIRMASS ALOFT...WET GROUND AND NEAR SFC MOISTURE IS EXPECTED TO
PRODUCE PATCHY FOG WITH ALI TAF SITE THE MOST LIKELY LOCATION FOR
IFR VSBY`S. CAN NOT RULE OUT PATCHY FOG FOR LRD AND CRP TAF
SITES...BUT THESE AREAS ARE LESS LIKELY...THUS WILL NOT MENTION IN
TAFS AT THIS TIME. VFR CONDITIONS ARE EXPECTED BY MID MORNING
SUNDAY...CONTINUING THROUGH THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 710 PM CDT SAT SEP 12 2015/
DISCUSSION...SEE AVIATION BELOW FOR 00Z UPDATE.
AVIATION...VFR WILL PREVAIL ACROSS SOUTH TEXAS THIS EVENING WITH
SCATTERED CLOUDS AND LIGHT EASTERLY WINDS. LIGHT FOG WILL BE
POSSIBLE AT TIMES DURING THE EARLY MORNING BEFORE DAYBREAK AT ALI
AND VCT...BRINGING MVFR VSBYS. MVFR CIGS MAY DEVELOP DURING THE
EARLY MORNING AS WELL AT VCT. VFR CONDITIONS WILL PREVAIL THROUGH
THE PERIOD AT CRP. OVER LRD ALSO ANTICIPATE MVFR CIGS WITH A
BROKEN CLOUD DECK DEVELOPING DURING THE EARLY MORNING AND LASTING
THROUGH THE MID MORNING. WINDS WILL REMAIN LIGHT THROUGH THE
PERIOD...BECOMING MORE NNE OVERNIGHT...AND TURNING E DURING THE
DAY SUNDAY.
PREV DISCUSSION... /ISSUED 244 PM CDT SAT SEP 12 2015/
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...THE TREND THROUGH THE
SHORT TERM WILL BE DRIER AIR MOVING INTO SOUTH TEXAS. PRIOR TO
THIS THOUGH...ISOLATED SHOWERS WILL CONTINUE THIS AFTERNOON
ACROSS THE GULF WATERS AND SOUTHERN/WESTERN SECTIONS OF THE CWA.
LATEST RUN OF THE HRRR SUPPORTS THIS AND WILL KEEP 20 POPS FOR
THESE AREAS THROUGH 00Z. PLEASANT CONDITIONS CAN BE EXPECTED
TONIGHT WITH LOWS FALLING INTO THE MIDDLE 60S ACROSS THE NORTH
WITH LOWER 70S ELSEWHERE. DRY AIRMASS WILL BE ENTRENCHED ACROSS
SOUTH TEXAS BY SUNDAY AS PW VALUES FALL BELOW 1.5 INCHES. HIGHS
WILL STILL BE ABLE TO CLIMB INTO THE UPPER 80S ACROSS THE EAST
WITH LOWER 90S TOWARDS THE RIO GRANDE PLAINS. SIMILAR TEMPERATURES
TO TONIGHT ARE ALSO ANTICIPATED ON SUNDAY NIGHT.
LONG TERM (MONDAY THROUGH SATURDAY)...THE PERIOD WILL BEGIN MOSTLY
DRY AS THE DRIER AIRMASS INVADING THE AREA TODAY REMAINS IN PLACE.
THEREAFTER DEEP MSTR WILL INCREASE AS EASTERLY FLOW STRENGTHENS AND
A WEAK COASTAL TROUGH DEVELOPS. CHC POPS WILL BE CONTINUED NEAR THE
COAST AND OFFSHORE THROUGH THE MIDDLE AND END OF THE WORKWEEK WITH
LOWER POPS WEST. MID LEVEL RIDGING STRENGTHENS LATE WEEK AND INTO
THE WEEKEND SO POPS WILL BE CONFINED TO THE FAVORED SEABREEZE AREAS.
MEX TEMPERATURES LOOK TOO WARM ACRS THE BOARD...ESPLY IN LIGHT OF
RECENT RAINS AND HV UNDERCUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 71 89 74 89 76 / 0 10 20 30 30
VICTORIA 65 88 69 88 74 / 0 10 10 20 20
LAREDO 71 95 73 95 75 / 0 10 0 10 10
ALICE 68 92 72 92 74 / 0 10 10 20 10
ROCKPORT 73 87 77 87 79 / 0 10 20 30 40
COTULLA 69 94 71 95 74 / 0 0 0 10 10
KINGSVILLE 70 91 73 91 75 / 0 10 10 30 20
NAVY CORPUS 74 87 77 87 78 / 0 10 20 30 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TE/81...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
146 AM EDT SUN SEP 13 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE EAST OF THE AREA OVERNIGHT. AN
UPPER LEVEL LOW WILL FOLLOW THE FRONT OVERNIGHT BEFORE EXITING
SUNDAY MORNING. COOL HIGH PRESSURE WILL BUILD IN ON SUNDAY AND
REMAIN ABOUT OVERHEAD THROUGH MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 120 AM EDT SUNDAY...
INCREASED POPS THIS MORNING IN THE EAST TO MATCH UP WITH RADAR AND
MODEL TRENDS.
AS OF 1010 PM EDT SATURDAY...
A COLD FRONT EXTENDED FROM A LOW IN PENNSYLVANIA TO A LOW ALONG
THE NORTH CAROLINA/SOUTH CAROLINA BORDER. THE LOW IN THE CAROLINAS
WILL TRACK NORTHEAST ALONG THE BOUNDARY TONIGHT AND MAY PUSH LOW
LEVEL MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING AREA BEFORE
12Z/8AM. RADAR AT 02Z WAS ALREADY SHOWING THE DEVELOPMENT OF
LIGHT SHOWERS IN THE NORTH CAROLINA FOOTHILLS. THE LATEST RUNS OF
THE HRRR AND LOCAL WRF HAVE SCATTERED SHOWERS MOVING ACROSS THE
SOUTHEAST COUNTIES OF THE FORECAST AREA BEFORE 12Z/8AM.
WATER VAPOR LOOP SHOWED THE UPPER LOW ALONG THE INDIANA/KENTUCKY
BORDER. MUCH COLDER AIR ALOFT WITH THIS FEATURE AS WELL AS THE
STRONG VORTICITY ADVECTION WILL RESULT IN SCATTERED SHOWERS OVER
SOUTHWEST VIRGINIA OVERNIGHT. THE LIFT WILL GRADUALLY TRANSITION
TO MORE UPSLOPE FORCING BY MORNING...SHIFTING THE BEST PROBABILITY
OF SHOWERS NORTH INTO SOUTHEAST WEST VIRGINIA. HAVE ADJUSTED THE
PROBABILITY OF PRECIPITATION FOR THESE TRENDS.
OTHERWISE ONSET OF DECENT COOL ADVECTION TO TAKE SHAPE BEHIND THE FRONT
OVERNIGHT WITH INCREASING UPSLOPE UNDER THE UPPER LOW AND FALLING 85H
TEMPS ESPECIALLY MOUNTAINS. APPEARS ENOUGH LIFT WITH THIS FEATURE TO
SUPPORT ADDED SHRA WEST WITH EVEN SOME POTENTIAL TO SEE SOME COVERAGE
SPILL EAST UNTIL BETTER DOWNSLOPE ARRIVES VERY LATE. THIS SUPPORTS HIGH
CHANCE TO LOW LIKELYS WEST AND CHANCE TO SLIGHT POPS EAST. KEPT
LOWS NEAR OR SLIGHTLY WARMER THAN MOS ESPCLY PIEDMONT WHERE COOL
ADVECTION WILL BE MUCH WEAKER AND MAY KEEP LOWS CLOSER TO 60.
OTHERWISE MOSTLY 50S FOR LOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 230 PM EDT SATURDAY...
AN UPPER LEVEL TROUGH WILL PIVOT ACROSS THE REGION SUNDAY MORNING.
MOISTURE AND OROGRAPHICAL LIFT WITH THIS TROUGH WILL BRING RAIN
SHOWERS TO THE MOUNTAINS...MAINLY ALONG WESTERN SLOPES. AS THE AXIS
OF THIS TROUGH SHIFTS EAST IN THE AFTERNOON...DRIER AIR IN NORTHWEST
FLOW WILL DECREASE THE CHANCE FOR SHOWERS AND EVENTUALLY CLOUDS
THROUGH SUNDAY AFTERNOON AND EVENING. BREEZY CONDITIONS WILL ALSO
FOLLOW THE PASSING OF THIS UPPER LEVEL TROUGH DURING THE
AFTERNOON...THEN DECOUPLE OVERNIGHT AS HIGH PRESSURE BUILDS IN FROM
THE WEST. THIS AREA OF HIGH PRESSURE WILL RESIDE OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. NO RAIN IS EXPECTED WHILE THIS
RIDGE IS OVER THE AREA. TEMPERATURES SUNDAY WILL RUN 10F COOLER THAN
NORMAL. BY TUESDAY...TEMPERATURES WILL RETURN TO NORMAL. MOST
LOCATIONS WILL SEE OVERNIGHT LOWS DROPPING INTO THE 40S...ESPECIALLY
ACROSS THE WEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 245 PM EDT SATURDAY...
HIGH PRESSURE WILL REMAIN OVER THE REGION FOR THE REMINDER OF THE
WORKWEEK. A WEAK COLD FRONT WILL APPROACH THE AREA NEXT
WEEKEND...BUT WILL LIKELY STALL OVER THE OHIO VALLEY. THE CHANCES
FOR RAIN WILL REMAIN NEAR ZERO THROUGH FRIDAY AND MAY EDGE INTO THE
20 PERCENT RANGE FOR THE MOUNTAINS NEXT WEEKEND AS THE FRONT GET
CLOSER TO THE AREA. AS THE REGION IS ENGULFED IN THE WARM
SECTOR...TEMPERATURES WILL BECOME WARMER THAN NORMAL BY THE WEEKEND.
IF THE FRONT REMAINS TO THE WEST...ABOVE NORMAL TEMPERATURES ARE
POSSIBLE NEXT WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 146 AM EDT SUNDAY...
A COLD FRONT THIS MORNING IS MOVING EAST ACROSS EASTERN PORTIONS
OF FORECAST AREA. THE COMBINATION OF MOISTURE AND LIFT ALONG THE
FRONTAL BOUNDARY IS CREATING MVFR SHOWERS. AS THE UPPER
TROUGH/UPPER LOW PASSES OVERHEAD...EXPECT OCCASIONAL SHOWERS
THROUGH THIS AFTERNOON...ESPECAILLY ACROSS THE WEST. SKIES WILL
IMPROVE THIS EVENING AS THE UPPER LOW LIFTS OUT AND SURFACE HIGH
PRESSURE BUILDS IN FROM THE WEST. VFR CONDITIONS EXPECTED TONIGHT
INTO MONDAY.
MEDIUM TO HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS
DURING THE TAF PERIOD.
EXTENDED AVIATION DISCUSSION...
HIGH PRESSURE WILL SETTLE ACROSS US THROUGH THE MIDDLE OF NEXT
WEEK KEEPING PRIMARILY VFR CONDITIONS IN PLACE. EXCEPTIONS COULD
BE SOME FOG AT KLWB/KBCB DURING THE DAWN HOURS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...AMS/KK
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...KK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
355 AM MDT TUE SEP 15 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 355 AM MDT TUE SEP 15 2015
A LARGE SCALE TROUGH CONTINUES TO DEEPEN OVER THE INTERMOUNTAIN
WEST THROUGH THESE PERIODS BRINGING CONTINUED UNSETTLED AND WINDY
WEATHER TO THE FORECAST AREA.
THE THIRD IN A SERIES OF DISTURBANCES WAS WORKING THROUGH THE
CENTRAL FORECAST AREA THIS MORNING AND WILL PUSH THROUGH THE
EASTERN CWA BEFORE NOON. MOISTURE ERODES SOMEWHAT BEHIND THIS
WAVE...WITH PRECIPITABLE WATER VALUES DROPPING FROM 1.0 TO 0.75
INCH. STORMS BECOME MORE NUMEROUS OVER NE UTAH AND NW COLORADO
THIS AFTERNOON WITH JET SUPPORT THERE AND THE TAIL OF A WEAKENING
SURFACE FRONT TRYING TO DROP INTO THE UINTA MOUNTAINS. STORM
MOTION REMAINS STRONG...TO THE NE AT 35-40KTS. THERE IS GOOD
POTENTIAL FOR LOCALIZED STRONG WIND GUSTS FAVORING THE NORTH THIS
AFTERNOON.
TONIGHT THROUGH WEDNESDAY...SCATTERED STORMS CONTINUE TO IMPACT
THE FORECAST AREA. MOISTURE REMAINS MARGINAL AT 0.5 TO 0.75 PRECIP
WATER. STORM MOTION INCREASES ON WEDNESDAY TO NEAR 50KTS
THREATENING MORE WIDESPREAD WIND GUSTS AND EVEN SOME POTENTIAL
DAMAGING WINDS. THE CURRENT FORECAST GRIDS HAVE GUSTS TO 45 MPH IN
PORTIONS OF EASTERN UTAH AND NW COLORADO FOR WEDNESDAY AFTERNOON.
WIND ADVISORIES MAY BE NECESSARY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 355 AM MDT TUE SEP 15 2015
UTAH AND COLORADO IS CAUGHT BETWEEN A BROAD WEST COAST TROUGH AND
EAST COAST RIDGE FROM WEDNESDAY NIGHT INTO THURSDAY NIGHT.
EMBEDDED FAST MOVING IMPULSES WILL BE STREAMING ACROSS THE
FORECAST AREA...SKIRTING THE NRN PORTION OF THE FORECAST AREA. THE
FAR SOUTH WILL HAVE LESS CONVECTIVE ACTIVITY. THE LAST PROMINENT
SHORT WAVE MOVES ACROSS WYOMING THURSDAY NIGHT...WITH TRAILING
ENERGY DRAGGING OVER NE UTAH/NW COLORADO. THERE ARE WEAKER SHORT
WAVES THAT CROSS UTAH AND COLORADO DURING THE WEEKEND...BUT DO NOT
HAVE MUCH MOISTURE. ANY SHOWERS/STORMS MAY BE LIMITED TO THE SWRN
COLORADO MOUNTAINS. COOLER AIR FOLLOWS THE THURSDAY NIGHT SHORT
WAVE AND THIS SHOULD RESULT IN WIDESPREAD FREEZING TEMPS ACROSS NW
COLORADO BY SATURDAY MORNING. THE WESTERLIES RETREAT NORTHWARD
SUNDAY AND MONDAY FOR DRY WEATHER ACROSS THE FORECAST AREA...
EXCEPT FOR A SLIGHT CHANCE OF AN AFTERNOON STORM OVER THE SAN JUAN
MOUNTAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1158 PM MDT MON SEP 14 2015
SHORT WAVE FROM ARIZONA WILL MOVE NORTHEAST ACROSS THE FORECAST
AREA AFTER 10Z THIS MORNING. WIDESPREAD SHOWERS WITH EMBEDDED
THUNDERSTORMS ARE EXPECTED BETWEEN 10Z-15Z USING HRRR AS GUIDANCE.
ADDITIONAL SHOWERS/STORMS WILL CONTINUE AFTER 15Z AS THE AIR MASS
REMAINS CONDITIONALLY UNSTABLE. SHOWERS/STORMS BECOME LESS
NUMEROUS TUESDAY EVENING. PASSING SHOWERS/STORMS WILL LOWER CIGS
BELOW ILS BREAKPOINTS AT MOUNTAIN TAF SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM...PF
AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1158 PM MDT MON SEP 14 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 202 PM MDT MON SEP 14 2015
ON THE HEAL OF THE SHORTWAVE TROUGH AND TROPICAL STORM REMNANTS
THAT MOVED THROUGH THE FORECAST AREA EARLIER TODAY...A SECOND
SHORTWAVE WILL AFFECT THE AREA THIS EVENING THROUGH LATE TONIGHT.
THIS WAVE WILL MOVE OVER AREA THAT RECEIVED MORE SUNSHINE THIS
AFTERNOON AND THERE SHOULD BE MORE CAPE REMAINING TO HELP SHOWERS
AND THUNDERSTORMS DEVELOP. HAVE INCREASED PRECIP AREAL COVERAGE OVER
SE UT AND SW AND WEST-CENTRAL CO EARLY THIS EVENING AND SPREAD
THOSE TO THE NE OVERNIGHT. AFTER ABOUT 09Z THE VORT MAX SHOULD BE
MOVING OUT OF THE AREA TO THE NE SO LOWERED CLOUD COVER AND POPS
TOWARD SUNRISE.
THE WET AND BREEZY PERIOD WILL CONTINUE THROUGH TUESDAY AS MOIST
SOUTHWEST FLOW PERSISTS WITH ENERGY FROM A STRONG TROUGH PUSHING
INTO THE PACIFIC NORTHWEST. PRECIPITATION WILL COME IN WAVES AS
VORTICITY MAXIMA STREAM TO THE FOUR CORNERS REGION IN THE STRONG
SOUTHWEST FLOW. CONSIDERED WIND ADVISORIES FOR NORTHWEST COLORADO
BUT NOT FEELING CONFIDENT ON SUSTAINED 30+ MPH WINDS WITH CLOUD
COVER EXPECTED THROUGHOUT THE DAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 202 PM MDT MON SEP 14 2015
THE INTERMOUNTAIN WEST WILL REMAIN IN A WET TROUGHY PATTERN
THROUGH THURSDAY BEFORE A SHORT BREAK IN THE ACTIVE WEATHER ON
FRIDAY AS A TRANSITORY RIDGE MOVES THROUGH THE REGION. THE TROUGHY
PATTERN RETURNS ON SATURDAY BUT BY SUNDAY WEAK HIGH PRESSURE MOVES
IN AGAIN. FORECAST MODELS ARE NOT PICKING UP MUCH IF ANY PRECIPITATION
ACROSS THE REGION SUNDAY THROUGH TUESDAY...BUT BEING IN ZONAL FLOW
BETWEEN TROUGHINESS TO THE NORTH AND HIGH PRESSURE TO THE SOUTH
THERE STILL MAY BE SOME SHOWERS AROUND AND THIS SOLUTION COULD
WAVER A BIT. CONSISTENCY ON MOISTURE DECREASING ON FRIDAY THROUGH
TUESDAY WITH THE EXCEPTION OF SATURDAY WHEN SHOWERS ARE LIKELY TO
INCREASE ACROSS SOUTHWEST COLORADO FOR THE DAY.
THE BIG TAKE AWAY IS THAT WE ARE EXPECTING BREAKS IN THE
WEATHER THROUGHOUT THE NEXT 7 DAYS...BUT WHATEVER BREAKS OCCUR
WILL NOT LAST LONG. AN EXTENDED DRY PERIOD IS NOT LIKELY IN THE
FORESEEABLE FUTURE ACROSS EASTERN UTAH AND WESTERN COLORADO.
TEMPERATURES WILL REMAIN NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1158 PM MDT MON SEP 14 2015
SHORT WAVE FROM ARIZONA WILL MOVE NORTHEAST ACROSS THE FORECAST
AREA AFTER 10Z THIS MORNING. WIDESPREAD SHOWERS WITH EMBEDDED
THUNDERSTORMS ARE EXPECTED BETWEEN 10Z-15Z USING HRRR AS GUIDANCE.
ADDITIONAL SHOWERS/STORMS WILL CONTINUE AFTER 15Z AS THE AIR MASS
REMAINS CONDITIONALLY UNSTABLE. SHOWERS/STORMS BECOME LESS
NUMEROUS TUESDAY EVENING. PASSING SHOWERS/STORMS WILL LOWER CIGS
BELOW ILS BREAKPOINTS AT MOUNTAIN TAF SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...CC/JAM
LONG TERM...JAM
AVIATION...PF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
344 AM EDT TUE SEP 15 2015
.DISCUSSION...
...LOCALLY HEAVY RAINFALL POSSIBLE FOR MID TO LATE WEEK...
TODAY-TONIGHT... CLOCKWISE FLOW AROUND A SPRAWLING AREA OF HIGH
PRESSURE TO OUR NORTH WILL MAINTAIN EASTERLY FLOW TODAY. TO OUR
SOUTH...A TROUGH AXIS ASSOCIATED WITH THE REMNANTS OF T.C. GRACE
WILL MOVE THROUGH THE FLORIDA STRAITS WHILE A DECAYING FRONTAL
BOUNDARY MEANDERS OVER SOUTH FLORIDA.
LATEST RAP ANALYSIS INDICATES A COLUMN THAT IS SLOWLY
MOISTENING...THOUGH SOME MID LEVEL DRY AIR LINGERS ACROSS OUR
NORTHWESTERN AREAS. AS INDICATED BY THE CAPE WIND PROFILERS...LOW
LEVEL EASTERLY FLOW IS PRESENT FROM THE SURFACE THROUGH ABOUT 4000
FEET...AND PERHAPS A LITTLE DEEPER THESE LAST FEW HOURS. EXPECT
SCATTERED SHOWERS AND ISOLATED STORMS OVER THE SE COASTAL WATERS TO
SPREAD TO THE NORTH AND WEST THIS MORNING AS DEEPER MOISTURE MOVES
IN. THESE SHOWERS COMBINED WITH DIURNAL HEATING WILL PROVIDE A
CHANCE FOR SHOWERS AND STORMS ALONG THE COAST THROUGH EARLY THIS
AFTERNOON. EXPECT THE ATLANTIC SEA BREEZE...ALBEIT DIFFUSE...TO MOVE
INLAND AND ACT AS A FOCUS FOR ADDITIONAL STORM DEVELOPMENT OVER THE
INTERIOR THIS AFTERNOON. CANNOT RULE OUT ADDITIONAL SHOWERS AND
PERHAPS A STORM MOVING ONSHORE GIVEN THE LOW-LEVEL EASTERLY FLOW.
STEERING LAYER FLOW...850-700MB...APPEARS WEAK AGAIN
TODAY...ESPECIALLY NORTH OF THE TREASURE COAST SO WILL NEED TO WATCH
FOR SLOW MOVING DOWNPOURS.
DIURNALLY DRIVEN CONVECTION SHIFTS TO THE WEST COAST AFTER SUNSET
BEFORE FOCUS SHIFTS BACK TO THE ATLANTIC. MAINTAINED SCATTERED POPS
OVERNIGHT ALONG THE COAST FOR NOCTURNAL ACTIVITY OVER THE ATLANTIC.
WED...THE LOW LEVEL EASTERLY WAVE WILL MOVE SLOWLY WESTWARD TOWARD
THE SE/S CENTRAL GULF OF MEXICO WITH DEEP MOISTURE INCREASING IN THE
STRENGTHENING LOW LEVEL EASTERLY FLOW. A MID LVL TROUGH WILL MOVE
EASTWARD TOWARD THE ERN GULF AND INCREASE THE DEEP LAYER MOISTURE IN
THE H7-H3 LAYER OVER MUCH OF THE FL PENINSULA. LIKELY SHOWER CHANCES
ARE EXPECTED WITH A CHANCE OF STORMS ESPEC IN THE AFTERNOON. A
TIGHTENING PRESSURE GRADIENT WILL SUPPORT ENE/NE WINDS AT 10-15 MPH
WITH MAINLY CLOUDY SKIES. CONVERGENT SHOWERS BANDS WILL MOVE ONSHORE
AND PUSH INTO THE INTERIOR THROUGH THE DAY. PRECIPITABLE WATER
VALUES WILL INCREASE TO 2.0-2.1 INCHES INTO LATE AFTERNOON WITH
LOCALLY HEAVY RAINFALL POSSIBLE WITH ANY TRAINING RAIN BANDS THAT
MOVE ONSHORE.
WED NIGHT...THE EASTERLY WAVE SHOULD SHARPEN OVER THE GULF WITH
NUMEROUS SHOWERS CONTINUING ACROSS E CENTRAL FL. DEEP MOISTURE AND
SUPPORT FROM THE MID LVL TROUGH TO THE WEST SHOULD ALLOW FOR
ADDITIONAL SHOWERS TO DEVELOP THROUGH THE NIGHT AND ALSO MOVE
ONSHORE. MAINLY CLOUDY SKIES ARE EXPECTED WITH LOWS IN THE LOWER TO
MID 70S.
THU...00Z GFS PINCHES OFF A WEAK SFC LOW IN THE GULF ON THU WITH THE
NAM EVEN DEEPER WITH SFC DEVELOPMENT. OVERALL PATTERN WITH DEEP
MOISTURE...LOW LVL E/SE FLOW AND THE MID/UPR LVL TROUGH ACROSS THE
GULF WILL CONTINUE NUMEROUS SHOWERS AND THE CHANCE FOR STORMS.
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH PRECIPITABLE WATER
VALUES FROM 2.1-2.3 INCHES.
FRIDAY...LIKELY SHOWER/THUNDERSTORM CHANCES ARE EXPECTED AGAIN WITH
LITTLE MOVEMENT TO THE LOW IN THE GULF AND THE UPPER LVL TROUGH
STILL WEST OF THE AREA. 00Z GFS INDICATES A PIECE OF MID LVL SUPPORT
MAY EJECT TOWARD THE CENTRAL PENINSULA WITH DEEP MOISTURE
CONTINUING. ANOTHER MOSTLY CLOUDY DAY WITH THE RISK OF LOCALLY HEAVY
RAINFALL WITH SHOWERS AND STORMS IN THE AFTERNOON.
SAT-TUE...APPEARS THE MID LVL WAVE WILL PASS EAST OF THE AREA OVER
THE WEEKEND INTO EARLY NEXT WEEK WITH DEEP MOISTURE BEING SHUNTED
EAST OF THE PENINSULA BY SUNDAY INTO MONDAY. CONSENSUS POPS DROP TO
THE SCATTERED RANGE WHICH SEEMS REASONABLE GIVEN SOME DRYING ON THE
BACK SIDE OF THE MID LVL TROUGH AND LOW LVL WINDS SWITCHING TO THE
N/NE. SHOULD SEE MORE SUN TO THE END THE WEEK AND THE FIRST PART OF
NEXT WEEK. HIGHS EXPECTED IN THE UPPER 80S WITH LOW IN THE LOWER-MID
70S.
&&
.AVIATION... SCATTERED SHRA AND ISOLATED TSRA EXPECTED
TODAY...INITIALLY ALONG THE COAST SOUTH OF KTIX...THEN SPREADING
INLAND IN LOW LEVEL EASTERLY FLOW. CANNOT RULE OUT ISOLATED SHRA AND
TSRA ALONG THE COAST THROUGH THE DAY. LOWER EXPECTED COVERAGE AND
TIMING UNCERTAINTIES PREVENT THE ADDITION OF TEMPO GROUPS FOR
NOW...AND WILL PROVIDE AMENDMENTS AS NECESSARY BASED ON RADAR TRENDS.
&&
.MARINE... CLOCKWISE FLOW AROUND A SPRAWLING AREA OF HIGH PRESSURE
ON THE EAST COAST WILL MAINTAIN A GENTLE TO MODERATE BREEZE OVER THE
ATLANTIC WATERS. SEAS UP TO 4 FEET WITH A SHORT 5 TO 6 SECOND PERIOD
WILL MAKE CONDITIONS ROUGH OVER THE OPEN WATERS. LOCAL PRESSURE
GRADIENT WILL SUPPORT 10 TO 15 KNOTS...THOUGH AT TIMES
HIGHER...THROUGH TONIGHT. WIND AND SEAS WILL BE LOCALLY HIGHER IN
WESTWARD MOVING SCATTERED SHOWERS AND STORMS.
EAST WINDS ARE EXPECTED AROUND 15 KNOTS WED-THU WITH SEAS BUILDING
TO AROUND 4 FT. DECREASING WINDS AND SEAS ARE EXPECTED BY SATURDAY
AND SUNDAY WITH NE WINDS EXPECTED SUNDAY AS LOW PRESSURE MOVES EAST
OF THE AREA. NUMEROUS SHOWERS AND SCATTERED STORMS ARE EXPECTED
ACROSS THE WATERS WED-FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 85 76 85 74 / 50 30 60 60
MCO 89 76 86 74 / 40 20 60 60
MLB 86 78 86 75 / 50 30 60 60
VRB 87 78 85 75 / 40 30 60 60
LEE 89 75 87 71 / 40 20 60 60
SFB 87 76 87 73 / 40 20 60 60
ORL 88 76 87 73 / 40 20 60 60
FPR 88 77 86 76 / 40 30 60 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...ULRICH
LONG TERM....VOLKMER
AREA FORECAST DISCUSSION
NWS DES MOINES IA
403 AM CDT TUE SEP 15 2015
.SHORT TERM /TODAY/...
ISSUED AT 357 AM CDT TUE SEP 15 2015
COUPLE OF CHALLENGES IN THE SHORT TERM TODAY. HIGH PRESSURE REMAINS
STRONG ALOFT...OVER THE SOUTHEAST US WHILE LOW PRESSURE CONTINUES TO
ADVANCE INTO THE PLAINS. THE NET RESULT HAS BEEN A RATHER
NARROW...BUT WELL DEFINED MOISTURE RIBBON EXTENDING FROM THE GULF TO
NEARLY THE US CANADIAN BORDER. ALONG WITH THAT...SHORT WAVES AND
POCKETS OF STRONGER WARM AIR ADVECTION HAVE BEEN PASSING THROUGH THE
FLOW WITH WEAK ROUNDS OF SHOWERS/ISO THUNDER INITIATION. TODAY WILL
BE SIMILAR WITH THE POSSIBILITY OF SOME LATE MORNING/TO MID
AFTERNOON SHOWERS/THUNDERSTORMS MAINLY OVER THE WEST/NORTHWEST. ANY
STORMS THAT DO DEVELOP WILL BE ROOTED WELL ABOVE THE BOUNDARY LAYER
AND ELEVATED THROUGHOUT THE AFTERNOON. WINDS WILL BE QUITE STRONG
TODAY...ESPECIALLY ACROSS THE NORTH/NORTHWEST WHERE AMBIENT FLOW MAY
APPROACH 30 MPH WITH GUSTS OVER 40 AT TIMES. GFS BUFR SOUNDINGS
SUPPORT AN ADVISORY...BUT ISSUES OVER THE PAST SEVERAL MONTHS OF
DRIER THAN EXPECTED SOUNDINGS MAY BE ADDING TO MIXING LAYER HEIGHT
AND THUS POTENTIAL FOR OVERESTIMATES OF MAX WIND GUST. THE NAM HAS
BEEN SLIGHTLY MORE SUBDUED...BUT STILL RATHER BRISK FOR THIS TIME OF
THE YEAR. DESPITE THE CHALLENGE OF ACCEPTING THE GFS SOUNDINGS
TODAY...H850 WINDS WILL REACH 40 TO 50KT BY MID TO LATE AFTERNOON
WHICH STILL SUGGESTS A DAY WITH GUSTS APPROACHING HEADLINE CRITERIA.
TEMPS WILL RESPOND ACCORDINGLY WITH HIGHS IN THE LOWER TO MID 80S BY
AFTERNOON...SO WARM AND BREEZY FOR MID SEPTEMBER. WITH ANOTHER WEAK
WAVE AND WARM AIR ADVECTION MOVING ACROSS THE AREA TODAY...WILL KEEP
SOME POP CHANCES GOING AS PREVIOUSLY MENTIONED. GFS/NAM AND HRRR ALL
SUPPORT AT LEAST A SLIGHT CHANCE INTO THE AFTERNOON HOURS TODAY.
CLOUDS WILL BE IN AND OUT OF THE AREA WITH WAVE PASSAGE AND WARM AIR
ADVECTION TODAY. WINDS WILL BEGIN TO SUBSIDE AFTER 23Z.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 357 AM CDT TUE SEP 15 2015
TONIGHT THROUGH THURSDAY MORNING...WINDY CONDITIONS WILL CONTINUE
OVER THE STATE AS RIDGING OVER THE EASTERN THIRD OF THE US AND A LOW
PRESSURE SYSTEM EJECTING OFF THE NORTHERN ROCKIES WORKS TO KEEP THE
SURFACE PRESSURE GRADIENT RATHER TIGHT.
SHORTWAVES WILL ALSO CONTINUE TO PROPAGATE THROUGH THE SW UPPER
LEVEL FLOW...SPARKING OFF OPPORTUNITIES FOR A FEW SHOWERS/STORMS AT
TIMES. SLIGHT CHANCE POPS ARE GENERALLY SECLUDED TO NW IA TONIGHT
AND THEN MORE BROADLY ACROSS CENTRAL IOWA WED NIGHT/THUR MORNING. A
ROBUST INVERSION WILL GENERALLY DO A GOOD JOB OF SQUASHING PRECIP
POTENTIAL...BUT CONSIDERING A ROUGHLY 50KT LLJ AND PROGGED UPGLIDE
OF 100+MB...A FEW SHOWERS ARE LIKELY TO SPARK OFF. WED NIGHT/THUR
WILL SEE SIMILAR SET UP WITH AN INVERSION...THOUGH IT WILL BE
WEAKER...A NEARLY 50KT LLJ AND UPGLIDE OF 100+MB. ALSO PRESENT WILL
BE A BETTER MOISTURE PROFILE AND RESULTING ELEVATED CAPE AROUND 700-
1000 J/KG. MODELS RESULT IN KIND WITH MORE WIDESPREAD OPPORTUNITIES
FOR SHOWERS/STORMS. WHILE A BIT OF THUNDER IS POSSIBLE/LIKELY WITH
STORMS WED NIGHT/THUR MORNING...UNSUPPORTIVE DEEP SHEAR LIMITS
POTENTIAL FOR ANYTHING SEVERE.
THURSDAY THROUGH FRIDAY...THE WESTERN TROUGH FINALLY MAKES ITS WAY
EASTWARD ACROSS THE ROCKIES AND INTO THE PLAINS. A SURFACE LOW WILL
DEVELOP AHEAD OF THE MAIN TROUGH AND TREKS ACROSS THE DAKOTAS AND
NORTHERN MN WED AND THUR. THE TRAILING SURFACE FRONT WILL BEGIN TO
MOVE INTO THE AREA THURSDAY AFTERNOON...SPARKING OFF SHOWERS/STORMS
ALONG THE WAY. MODELS THE LAST COUPLE OF RUNS HAVE HINTED AT
STALLING THE BOUNDARY ACROSS THE SOUTH AND NORTHERN MO...AND
CONTINUE WITH THAT SOLUTION. THEN FRIDAY THE MAIN UPPER LEVEL TROUGH
PUSHES THROUGH THE REGION AND PROVIDES ANOTHER OPPORTUNITY FOR
SHOWERS/STORMS. WITH TEMPS AND DEW PTS AT THEIR HIGHEST OF THE
WEEK...A DECENT AMOUNT INSTABILITY WILL BE AROUND THURSDAY...AROUND
1000-2000 J/KG. A GENERALLY LACKLUSTER SHEAR PROFILE WILL LIMIT
SEVERE POTENTIAL. STORY FRI IS SIMILAR...THOUGH FURTHER SOUTH
WHEREVER THE REMNANT/STALLED FRONT ENDS UP.
SATURDAY THROUGH TUESDAY...HIGH PRESSURE SETS IN BEHIND THE FRONT
AND TEMPERATURES FALL BACK INTO THE 70S...MAKING FOR A PLEASANT
WEEKEND AND START TO THE NEW WEEK.
&&
.AVIATION...15/06Z
ISSUED AT 1049 PM CDT MON SEP 14 2015
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. SOUTHERLY WINDS
TO INCREASE A BIT OVERNIGHT...AND PICK UP EVEN MORE BECOMING
QUITE GUSTY TUESDAY. GUSTS SHOULD THEN DIMINISH SOME TUESDAY
EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...CURTIS
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
532 AM EDT TUE SEP 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 531 AM EDT TUE SEP 15 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF DEVELOPING OVER THE
WRN CONUS WHICH IS FORCING A BUILDING DOWNSTREAM RIDGE OVER THE ERN
CONUS. RESULTING SW FLOW INTO THE UPPER GREAT LAKES IS GENERALLY
QUIET. HOWEVER...A VERY PRONOUNCED ELEVATED MIXED LAYER/VERY STEEP
MID LEVEL LAPSE RATES OF 8-9C/KM EVIDENT ON 00Z SOUNDINGS ACROSS THE
CNTRL/NRN PLAINS AND UPPER MISSISSIPPI VALLEY IS SUPPORTING A FEW
SHRA/TSRA ACROSS PORTIONS OF CNTRL/SRN WI EARLY THIS MORNING WHERE A
POOL OF HIGHER 700MB THETA-E IS LOCATED PER RAP ANALYSIS. CLOSER TO
HOME...CLR SKIES HAVE BEEN THE RULE OVERNIGHT. HOWEVER...SRLY FLOW
UP LAKE MICHIGAN HAS BEEN ADVECTING HIGHER DWPTS INTO THE COOLER
INTERIOR...RESULTING IN SOME PATCHY FOG/STRATUS.
ANOTHER WARM LATE SUMMER DAY IS ON THE WAY TODAY. ALTHOUGH 850MB
TEMPS WILL BE ON THE ORDER OF 18-20C TODAY...PROBABLY WON`T BE ABLE
TO MIX TO 850MB AND REALIZE THAT WARMTH GIVEN THE STRONG INVERSION
AND LOWER SUN ANGLE THIS TIME OF YEAR. EXPECT MAX TEMPS IN THE UPPER
70S TO MID 80S...WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
HIGHS ALONG THE LAKE MICHIGAN SHORE E OF KESC WILL BE AROUND 70F.
TIGHTENING GRADIENT BTWN NORTHERN PLAINS LOW PRES AND HIGH PRES TO
THE ESE WILL SUPPORT BREEZY SSW WINDS THIS AFTN AS NOTED ON FCST
SOUNDINGS. MIXED LAYER SUPPORTS WIND GUSTS INTO THE 25-30MPH RANGE
MOST AREAS WITH POTENTIAL TO GUST TO AROUND 35MPH WHERE DOWNSLOPE
WARMING AIDS MIXING DEPTH. NOT OUT OF THE QUESTION THAT A FEW
SPRINKLES OR ISOLD -SHRA COULD OCCUR THIS MORNING OVER THE SCNTRL/E
AS POOL OF HIGHER 700MB THETA-E LIFTS NE. WITH VERY DRY AIR BLO THE
10KFT+ HIGH CLOUD BASES...WILL LEAVE FCST DRY FOR NOW AND MONITOR
UPSTREAM PCPN EVOLUTION.
LOW-LEVEL JET CONTINUES TO RAMP UP TONIGHT WITH WINDS AT THE 2KFT
LEVEL UP TO 50-60KT W AND 40-45KT E. COULD BE A SET UP FOR WINDY
CONDITIONS IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR SUCH AS
MARQUETTE. OTHERWISE...WITH STRENGTHENING NOCTURNAL INVERSION...
GUSTS WILL ONLY BE 10-20MPH. THE WINDS WILL KEEP TEMPS UP TONIGHT.
EXPECT MINS IN THE UPPER 50S TO UPPER 60S...WARMEST IN THE DOWNSLOPE
AREAS NEAR LAKE SUPERIOR. WITH PRONOUNCED ELEVATED MIXED LAYER/VERY
STEEP MID LEVEL LAPSE RATES OVER THE AREA...CAN`T COMPLETELY RULE
OUT AN ISOLD SHRA OR TSTM AS LOW-LEVEL JET INCREASES WITH ANOTHER
PUSH OF 700MB THETA-E. HOWEVER...GIVEN THE OVERALL DRY AIR MASS...
POTENTIAL APPEARS TOO LOW TO INCLUDE A MENTION OF PCPN IN FCST. IN
ADDITION...THERE ARE FEWER MODEL RUNS INDICATING PCPN TONIGHT
COMPARED TO PREVIOUS RUNS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 338 AM EDT TUE SEP 15 2015
THE CWA WILL CONTINUE TO BE UNDER SW FLOW ALOFT BETWEEN RIDGING TO
THE E AND TROUGHING TO THE W. SEVERAL SHORTWAVES WILL PASS NEARBY
FROM MID TO LATE WEEK.
FOR WED...SLIGHT CHANCE POPS OVER MAINLY THE WRN CWA SEEMS
REASONABLE GIVEN THAT A SHORTWAVE WILL STAY NW OF THE AREA
(SASKATCHEWAN AND FAR NW ONTARIO) AND DRY LOW-MID LEVELS WILL
PREVENT MOST AREAS FROM SEEING PRECIP. EXPECT HIGH TEMPS FROM THE
MID 70S NEAR LAKE MICHIGAN TO THE MID 80S NEAR LAKE SUPERIOR AS SSW
WINDS GUSTING TO 20-25 KTS DOWNSLOPE TOWARD THE BIG LAKE.
PRECIP CHANCES BEGIN INCREASING WED NIGHT AS A STRONGER SHORTWAVE
AND SFC LOW MOVE CLOSER TO THE CWA...ACROSS NRN MN AND INTO ONTARIO.
STILL ONLY HAVE CHANCE POPS WED NIGHT INTO THU AFTERNOON...BUT
SHOWERS AND THUNDERSTORMS BECOME LIKELY THU EVENING AND THU NIGHT AS
THE SFC TROUGH/COLD FRONT MOVE W-E ACROSS THE AREA. THINK THERE
COULD BE SOME STRONG TO SEVERE STORMS THU EVENING AS MUCAPE VALUES
LOOK TO BE 1000-2000 J/KG AND DEEP LAYER SHEAR IS AROUND 30KTS. CAPE
AND EFFECTIVE SHEAR DIMINISH LATER IN THE EVENING AND OVERNIGHT THU
NIGHT AS STORMS BECOME ELEVATED...SO SEVERE THREAT WILL ALSO
DIMINISH. PLENTY OF MOISTURE OVERHEAD WILL ALLOW FOR BRIEF HEAVY
RAINFALL. THU TEMPS LOOK TO BE A LITTLE COOLER THAN WED DUE TO
INCREASED CLOUD COVER...BUT WILL STILL SEE HIGHS ABOVE NORMAL IN THE
70S TO AROUND 80...WARMEST NEAR LAKE SUPERIOR.
LOTS OF UNCERTAINTY FOR FRI INTO SAT AS MODELS VARY ON HANDLING A
SHORTWAVE MOVING UP THE FRONT AND INTO THE GREAT LAKES REGION.
TIMING...TRACK AND STRENGTH OF THE SHORTWAVE WILL GREATLY IMPACT
WEATHER OVER THE CWA. FOR NOW...MODELS ARE IN SOME GENERAL AGREEMENT
THAT MAINLY THE SERN 1/2 TO 2/3 OF THE CWA WILL BE EFFECTED BY
PRECIP...BUT THEY DO DIFFER ON TIMING AND STRENGTH. WILL JUST USE A
CONSENSUS OF GUIDANCE AT THIS TIME. IT WILL BE QUITE A BIT COOLER
BEHIND THE FRONT...EXACTLY HOW MUCH DEPENDS ON PRECIP/CLOUD
COVER...BUT HIGHS IN THE 60S TO LOW 70S SEEMS REASONABLE.
SFC HIGH PRESSURE THEN LOOKS TO MOVE THROUGH OVER THE WEEKEND...WITH
SW FLOW ON THE BACK SIDE EARLY NEXT WEEK. NO PRECIP IS EXPECTED FROM
AT LEAST LATE SAT ON...AND TEMPS WILL GRADUALLY WARM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 130 AM EDT TUE SEP 15 2015
WITH A DRY AIRMASS IN PLACE...VFR CONDITIONS WILL PREVAIL AT
KIWD/KCMX/KSAW THROUGH THIS FORECAST PERIOD. WITH DAYTIME HEATING
TODAY...SRLY WINDS WILL AGAIN BECOME GUSTY BY LATE MORNING
ESPECIALLY AT KIWD AND KSAW. THE GRADIENT WILL BE STRONG ENOUGH TO
ALSO SUPPORT GUSTY WINDS THROUGH THE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 531 AM EDT TUE SEP 15 2015
WINDY CONDITIONS ARE SHAPING UP FOR LAKE SUPERIOR THRU THU AS LAKE
SUPERIOR WILL BE SITUATED BTWN A LOW PRES TROF TO THE NW AND HIGH
PRES TO THE ESE. SOUTHERLY WINDS WILL SLOWLY RAMP UP TODAY AND WILL
REACH GENERALLY 15-25KT W HALF TO 20-30KT E HALF TONIGHT. NOT OUT OF
THE QUESTION THAT THE HIGHEST OBS PLATFORMS WILL SEE GALE FORCE
GUSTS. WINDS WILL DIMINISH SOME WED/THU...MORE SO OVER THE W HALF OF
THE LAKE. A COLD FRONT WILL PASS THU NIGHT/FRI MORNING WITH
GENERALLY 10-20KT WINDS TO FOLLOW INTO THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
1143 PM CDT MON SEP 14 2015
.UPDATE...
ISSUED AT 1141 PM CDT MON SEP 14 2015
WE ADDED AN ISOLATED SHOWER TO OUR SOUTHEAST ZONES THROUGH THE
EARLY MORNING HOURS AS A WEAK SHORTWAVE MOVES THROUGH THAT AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM CDT MON SEP 14 2015
A WEAK FRONT DRAPED ACROSS THE REGION TODAY HAS BEEN FAIRLY
INACTIVE...WITH AN AREA OF STRATUS TO ITS NORTH THAT HAS BEEN
KEEPING TEMPERATURES COOL ALONG THE CANADIAN BORDER. HAVE BEEN
WATCHING SOME CHAFF ON THE RADAR OVER THE NORTH SHORE THAT WAS
INITIALLY CONCERNING DUE TO ITS PROXIMITY TO THE FRONT...BUT THERE
ARE NO CLOUDS ACCORDING TO SATELLITE AND DO NOT EXPECT ANY TO FORM.
SOME WEAK/ELEVATED SHOWERS HAVE FORMED FARTHER WEST ALONG THE BORDER
IN THE DETROIT LAKES AREA. THESE DO NOT HAVE MUCH FOR CAPE TO
PRODUCE MORE THAN A FEW SHOWERS...SO HAVE KEPT POPS TO SLIGHTS AND
ONLY FOR THE NEXT FEW HOURS AND HAVE NOT PUT IN ANY THUNDER. THE
NEXT SIGNIFICANT CONCERN TONIGHT IS THE STRATUS ALONG THE CANADIAN
BORDER. MODELS HAVE BEEN HANDLING THIS VERY POORLY IN GENERAL...BUT
EXPECT THAT IF THE STRATUS HAS NOT DISSIPATED IN THE NEXT FEW HOURS
IT WILL NOT...AND SHOULD BEGIN EXPANDING AGAIN AFTER SUNSET. LOW
LEVEL RH PROGS ARE IMPLYING WE WILL HAVE AN AREA OF STRATUS ALONG
THE CANADIAN BORDER FOR MUCH OF THE NIGHT...AND IT MAY EXPAND DOWN
TO AROUND THE IRON RANGE AFTER MIDNIGHT. HAVE GONE FAIRLY
PESSIMISTIC ON CLOUD COVER OVERNIGHT...AND WOULD NOT BE SURPRISED TO
SEE SOME SPRINKLES UP THERE TOWARDS MORNING. WITH ALL THE LOW LEVEL
RH...SOME FOG IS POSSIBLE SO HAVE PUT IN PATCHY FOG OVERNIGHT FOR
THE NORTH AS WELL. SOUTHERN PORTIONS OF THE FORECAST AREA SHOULD
STAY MOSTLY CLEAR AND DRY OVERNIGHT. TUESDAY THE FRONT PUSHES FAR
ENOUGH NORTH THAT WE SHOULD BE DRY AND EVEN CLEAR OUT. WE SHOULD
HAVE A WARM AND SOMEWHAT UNSTABLE AIRMASS...BUT IT WILL BE WEAKLY
CAPPED AND WITH NO SURFACE FEATURE TO HELP TRIGGER CONVECTION DO NOT
EXPECT ANY STORMS DURING THE DAY. HIGHS TUESDAY TO BE PUSHING
80...EVEN ACROSS THE NORTH AS LONG AS CLOUD COVER CLEARS OUT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM CDT MON SEP 14 2015
THE NORTHLAND WILL BE IN AN ACTIVE...WARM AND POTENTIALLY
STORMY...WEATHER PATTERN FOR THE MIDDLE OF THE WEEK. THE NORTHLAND
CAN EXPECT TEMPERATURES OF ABOUT 10 DEGREES ABOVE NORMAL FOR THE
MIDDLE OF THE WEEK THROUGH THURSDAY...WITH 850 HPA TEMPERATURES OF
ABOUT 15 TO 19 DEGREES CELSIUS. COOLER AND DRIER AIR WILL MOVE INTO
THE NORTHLAND LATER IN THE WEEK.
A STRONG SOUTHERLY LOW LEVEL JET WILL DEVELOP TUESDAY NIGHT AS A LOW
IN NORTH DAKOTA LIFTS INTO CANADA. THE MODELS ARE SUGGESTING THERE
COULD BE CONVECTION OVERNIGHT INTO EARLY WEDNESDAY WITH THE STRONG
JET. THE SOUTHERLY FLOW WILL BRING VERY HUMID AIR INTO THE REGION.
PRECIPITABLE WATER VALUES WILL LIKELY INCREASE TO AT LEAST THE 90TH
PERCENTILE OF CLIMATOLOGY.
THE LOW WILL LIFT INTO ONTARIO ON WEDNESDAY...AND ITS COLD FRONT
WILL MOVE INTO MINNESOTA AND THEN STALL SOMEWHERE OVER NORTHERN
MINNESOTA. THIS MEANS THE NORTHLAND WILL LIKELY REMAIN IN THE WARM
AND HUMID ZONE...AND WILL PROVIDE LOW CHANCES OF SHOWERS AND STORMS
OVER PARTS OF THE FORECAST AREA WEDNESDAY AND WEDNESDAY EVENING.
THE HIGHEST CHANCES OF SHOWERS AND STORMS WILL OCCUR LATE WEDNESDAY
NIGHT AND THURSDAY. THE GFS/ECMWF/GEM ARE INDICATING ANOTHER SURGE
OF WARM AND HUMID AIR WILL ACCOMPANY THE SOUTHERLY FLOW LATE
WEDNESDAY NIGHT AND THURSDAY AS ANOTHER LOW MOVES INTO THE NORTHERN
PLAINS. ITS COLD FRONT WILL THEN MOVE THROUGH THE NORTHLAND LATER IN
THE DAY ON THURSDAY AND OVERNIGHT INTO EARLY FRIDAY. INCREASED PCPN
CHANCES FOR THURSDAY AND THURSDAY NIGHT BASED ON A BLEND OF THE
GFS/ECMWF/GEM...WHICH ARE IN REASONABLE AGREEMENT.
FRIDAY WILL BE MUCH COOLER THAN THE MIDDLE OF THE WEEK. NW FLOW WILL
DEVELOP IN THE WAKE OF THE PASSING COLD FRONT...USHERING IN MORE
SEASONABLY APPROPRIATE 850 HPA TEMPERATURES OF 5 TO 7 DEGREES
CELSIUS. THE COOL FLOW...AND HUMIDITY FROM THE RAIN THE PREVIOUS
NIGHT...COULD RESULT IN WIDESPREAD BROKEN/OVERCAST CUMULUS DURING
THE DAY.
FOR THE UPCOMING WEEKEND...THE LATEST AND PREVIOUS GFS/EURO/GEM
GUIDANCE ARE SURPRISINGLY IN EXCELLENT AGREEMENT FOR THE FALL. AS A
RESULT FAIRLY CONFIDENT WITH A TROUGH EXITING THE FORECAST AREA
EARLY ON SATURDAY. BEHIND THE TROUGH...A RIDGE WILL BUILD IN FROM
THE WEST. BY LATE ON SATURDAY THE 500 HPA RIDGE AXIS WILL BE NEAR
THE EASTERN NORTHERN PLAINS OR OVER THE UPPER MIDWEST. AT 850 AND
925 HPA...WARM AIR ADVECTION WILL OCCUR LATE ON SATURDAY AND FOR THE
REST OF SUNDAY. AS A RESULT EXPECTING SEASONABLE TEMPERATURES ON
SATURDAY IN WAKE OF THE DEPARTING FRONT WITH READINGS IN THE 60S. ON
SUNDAY IT WILL BE MILDER WITH TEMPERATURES IN THE UPPER 60S AND LOW
70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 636 PM CDT MON SEP 14 2015
MVFR CEILINGS ALONG THE INTERNATIONAL BORDER WERE MOVING NORTH AND
SHOULD MOVE OUT OF KINL OVER THE NEXT 1 TO 2 HOURS. VFR CONDITIONS
WERE OCCURRING ELSEWHERE. A FRONTAL BOUNDARY WAS DRAPED ACROSS
NORTHERN MINNESOTA AS WELL THIS EVENING AND WE HAVE SEEN SOME
CLOUDS FORM ALONG IT. THE FRONT WILL MOVE BACK TO THE NORTH
TONIGHT TO NEAR THE INTERNATIONAL BORDER BY 12Z TUE.
CONFIDENCE IN LOWER CLOUD FORMATION TONIGHT IS LOWER THAN AVERAGE.
THE RAP WHICH HAS A GOOD HANDLE ON THE CURRENT MVFR CEILINGS IS
NOT VERY SUPPORTIVE OF ADDITIONAL DEVELOPMENT TONIGHT...AND THE
HRRR AGREES. THE SREF/NAM SUGGEST IFR/LOW MVFR CONDITIONS WILL
DEVELOP OVERNIGHT ALONG WITH SOME FOG. WE MADE SOME MINOR
ADJUSTMENTS IN THIS SET OF TAFS AND STILL FORECAST SOME LOWER
CLOUDS/FOG. AN INCREASING GRADIENT WILL LEAD TO VFR CONDITIONS
TUESDAY MORNING AS MIXING DEEPENS AND WINDS STRENGTHEN.
A LLJ WILL LEAD TO SOME LLWS IN SPOTS LATER TONIGHT TO ABOUT 14Z
TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 60 77 64 78 / 10 10 30 30
INL 56 76 65 78 / 10 10 20 30
BRD 63 79 67 81 / 10 10 20 20
HYR 62 79 65 80 / 10 10 30 20
ASX 56 82 64 81 / 10 10 30 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...LE
LONG TERM...GROCHOCINSKI/WL
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
303 AM CDT TUE SEP 15 2015
.DISCUSSION...
Issued at 303 AM CDT TUE SEP 15 2015
Over the next several hours, the development of a few isolated
showers and perhaps a stray thunderstorm continue to looks possible
where accas continues to develop and thicken across eastern KS. A
strong LLJ based around 1-1.5 kft and decent isentropic lift in the
310-315K layer will continue to support initiation through at least
sunrise if not a few hours after, and hi-res model guidance shows a
signal for precipitation by 11-12z with relatively good temporal and
spatial continuity. Any showers/storms that develop will drift east
before dissipating as the nocturnal LLJ diminishes diurnally later
in the morning, allowing skies to clear and temperatures to warm
into the mid to possibly upper 80s this afternoon. As was the case
yesterday, any mixing to a higher height than indicated in models
could bring highs several degrees warmer than forecast, but have
settled with a mixing height of around 925 hPa and somewhat
discounted the more extreme RAP solution which brings surface
temperatures near 90 degrees and surface dewpoints down to the upper
40s. Winds may be just a touch lighter this afternoon than
yesterday, but still with sustained speeds in the upper teens and
gusts to 25-30 mph especially during the late morning and early
afternoon.
The LLJ should focus more to the north and northeast tonight into
Wednesday morning, allowing any possible nocturnal convection to
develop and remain out of the forecast area. As a result, cloud
cover is not expected to hinder temperature rises, and highs could
reach the upper 80s CWA-wide Wednesday afternoon. Wednesday night
into early Thursday morning will be similar, but there is still a
decent signal for cold-pool driven storms sneaking into the
northeastern quadrant of the forecast area around sunrise, and thus
have continued lower-end PoPs for areas along/north of Hwy 36 and
east of STJ from after midnight through the late morning hours
Thursday.
On Thursday, a final lobe of surface low pressure will eject off the
lee-side of the Rockies and into the Dakotas, forcing its associated
cold front across the Plains and into the Great Lakes area Thursday
through Friday. The high temperature forecast Thursday will be
somewhat complicated as convergence ahead of the approaching cold
front enhances southerly surface flow and boundary layer mixing once
again, but while destructive warm-sector convection becomes probable
during the afternoon. Convective initiation should be shallow and
capped Thursday afternoon, then precipitation will become likely by
evening and especially the overnight hours into early Friday morning
along the boundary. The slow-moving nature of the front and PWAT
values on the order of 2 inches (over 150% of normal) may indicate
the potential for flash flooding as rounds of storms develop near
and ahead of the front, and while a few strong to marginally severe
storms are nearly always possible along a robust autumn cold front,
the main concern will likely be the heavy rains and flooding
potential.
After the front pushes out of the region on Friday evening, cooler
temperatures and gradually decreasing low-level moisture will make
for another autumn-like weekend across the region. While upper
heights do not fall quite as dramatically as with last weekend`s
system in the wake of the coming system, highs will likely top out
in the lower to mid 70s Saturday and a touch warmer in the mid to
upper 70s Sunday, before conditions once again moderate to near
normal early next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1204 AM CDT TUE SEP 15 2015
VFR conditions are expected through the period. Strong southerly
winds will persist overnight so despite 50kt winds about 1k ft wind
shear looks minimal. There also is a small chance for showers and
maybe a few storms early this morning as strong isentropic ascent
spreads over the region. Winds will increase Tuesday morning with
gusts to around 30 kts possible.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...CDB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1216 AM CDT TUE SEP 15 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT MON SEP 14 2015
FORECAST CONCERNS OVER THE NEXT COUPLE OF DAYS WILL BE IF
ELEVATED SHOWERS AND THUNDERSTORMS CAN DEVELOP WITHIN AREA OF WARM
MID LEVEL TEMPERATURES AND SUBTLE SHORTWAVE TROF PASSAGES WITH
SEASONABLY STEEP MID LEVEL LAPSE RATES AND SEASONABLY STRONG LOW
LEVEL JETS.
WE HAD SOME STORMS DEVELOP THIS MORNING WITH ONE OF THOSE WEAK
SHORTWAVE TROFS AND THIS HAS QUICKLY MOVED OFF TO THE EAST. ONE
WARNING WAS ISSUED WITH HAIL THE SIZE OF DIMES TO QUARTERS.
DEEPENING WEST COAST TROUGH WILL CHANGE OUR ZONAL FLOW TO MORE
SOUTHWEST DURING THE SHORT TERM. THE AREA WILL BE AFFECTED BY WEAK
SHORTWAVE IMPULSES EMBEDDED IN THE FLOW WITH ISOLATED TO SCATTERED
THUNDERSTORMS...SEASONABLY WARM TEMPERATURES AND GUSTY SOUTH
WINDS.
AT 20Z...SURFACE LOW PRESSURE WAS CENTERED NEAR PIERRE SOUTH
DAKOTA WITH BRISK SOUTH WINDS 15-20KTS AND GUSTY ACROSS THE
FORECAST AREA. TEMPERATURES HAD CLIMBED INTO THE 80S WITH
DEWPOINTS IN THE 60S.
TONIGHT...ANOTHER WEAK WEATHER DISTURBANCE WILL PUSH ACROSS THE
AREA. THE LOW LEVEL JET IS FORECAST TO STRENGTHEN AGAIN TO 40 TO
60KTS. 850MB MOISTURE SHOULD BE AROUND 10-12DEG C. AND THERE IS A
LITTLE POOLING OF H7 MOISTURE IN SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA ALONG WITH FRONTOGENESIS AND STEEP LAPSE RATES AROUND 8
DEGC/KM. WARM MID LEVEL TEMPERATURES OF 10-14DEGC ARE PROGGED
ACROSS THE AREA...HOWEVER THE MID LEVEL TEMPERATURES ARE EXPECTED
TO BE WEAKEST IN THE SOUTHEAST. THE HRRR/RAP AND HI RES ARW/NMM
ARE STILL FAIRLY DRY. THE EXPERIMENTAL HRRR DEVELOPS SOME ISOLATED
PRECIP NEAR THE MISSOURI RIVER 05-07Z. WILL INCLUDE ISOLATED
THUNDERSTORMS FOR PARTS OF SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
LATER NIGHT.
TUESDAY AFTERNOON...TEMPERATURES SHOULD HEAT INTO THE 80S AND
LOWER 90S AND WARM MID LEVEL TEMPERATURES SHOULD DECREASE DURING
THE AFTERNOON AND OVERNIGHT. THE 18Z NAM IS A LITTLE STRONGER WITH
THE CAP COMPARED TO THE PREVIOUS RUN...AND COULD LIMIT STORM
DEVELOPMENT FURTHER. ISOLATED ELEVATED STORMS MAY DEVELOP AHEAD
OF THE SURFACE TROF WITH SCATTERED THUNDERSTORMS POSSIBLE TUESDAY
NIGHT. MAINLY CONFINED POP MENTION TO PARTS OF NORTHEAST NEBRASKA
TUESDAY AFTERNOON AND NORTHEAST AND PARTS OF THE CENTRAL FORECAST
AREA TUESDAY NIGHT. HIGHS TUESDAY SHOULD TOP OUT IN THE 80S TO
LOWER 90S. THE FORECAST INSTABILITY IS 1000-2000 J/KG AND THE
WESTERN PART OF THE FORECAST AREA IS CLOSE TO THE MARGINAL RISK
FOR SEVERE WEATHER.
SOME STORMS COULD LINGER ACROSS THE EASTERN PART OF THE FORECAST
AREA WEDNESDAY...ALTHOUGH FOR NOW HAVE KEPT MAINLY HOT AND DRY.
THE FRONT SLOWLY PUSHES SOUTH THURSDAY WITH A CHANCE FOR SHOWERS
AND THUNDERSTORMS THURSDAY AFTERNOON ALONG THE FRONT IN SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA WITH CAPE VALUES OF 1500-2500J/KG.
HIGH WEDNESDAY AND THURSDAY SHOULD AGAIN BE IN THE 80S TO LOWER
90S AHEAD OF THE FRONT WITH COOLER TEMPERATURES IN THE NORTH
THURSDAY. PWATS REMAIN IN THE 1 TO 1.6 INCH RANGE DURING THE
SHORT TERM. GUSTY SOUTH WINDS 15-25KTS SUSTAINED WILL PERSIST
TUESDAY AND WEDNESDAY AND AHEAD OF THE FRONT THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON SEP 14 2015
THUNDERSTORMS SHOULD CONTINUE NEAR THE FRONT INTO THURSDAY NIGHT
WITH ADDITIONAL ACTIVITY FRIDAY WITH THE MAIN SHORTWAVE TROF.
MAINLY DRY WEATHER IS FORECAST FOR SATURDAY...AND DEPENDING ON THE
TIMING OF THE NEXT SHORTWAVE...COULD SEE SOME SHOWERS SUNDAY.
MORE SEASONABLE TEMPERATURES IN THE 70S FOR MUCH OF THE EXTENDED.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1214 AM CDT TUE SEP 15 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. OTHER THAN SOME
SCT MID AND HIGH LEVEL CLOUDS...GUSTY SOUTH WINDS ARE EXPECTED.
LOW-LEVEL WIND SHEAR IS ALSO EXPECTED OVERNIGHT ASSOCIATED WITH
THE STRONG LOW LEVEL JET...THAT SHOULD DECREASE BY MID MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1151 PM MDT MON SEP 14 2015
.AVIATION...
06Z TAF CYCLE
AREA OF -SHRA/TSRA OVER EASTERN AZ WILL ATTEMPT TO CLIP WEST
CENTRAL/NORTHWEST AREAS DURING THE PREDAWN HOURS. ACTIVITY
EXPECTED TO WANE TO -SHRA BY THE TIME IT REACHES EITHER KGUP
AND FMN. MID LEVEL CLOUD COVER WILL DRIFT OVER THE STATE THRU
SUNRISE. WINDS WILL BE NOTICEABLE STRONGER TUESDAY AND BECOME
BREEZY BY MID DAY MOST SITES. DRYING APPROACHING FROM THE
WEST WILL CAP STORM DEVELOPMENT AS WELL MOST SITES...AND LEAD
TO SKC DURING THE EVENING.
GUYER
&&
.PREV DISCUSSION...927 PM MDT MON SEP 14 2015...
.UPDATE...
THOUGH QUITE A BIT OF CLOUD COVER REMAINS ACROSS THE CWA...VERY
FEW SHOWERS AND THUNDERSTORMS REMAIN. ANOTHER SHORTWAVE WILL CROSS
NW NM TONIGHT...AND IS CURRENTLY ASSOCIATED WITH THE BROKEN LINE
OF CONVECTION ACROSS AZ. THIS LINE SHOULD CONTINUE TO TRACK
NE...BUT WILL BARELY BE MAKING IT TO THE NM DOORSTEP BY 12Z...AND
MODELS GENERALLY INDICATE IT WILL WEAKEN BEFORE CROSSING NM.
THUS...HAVE REDUCED POPS FOR THE REMAINDER OF THE OVERNIGHT...AND
THE HRRR INDICATES POPS COULD HAVE BEEN REDUCED FURTHER. DRIER
CONDITIONS STILL ON TAP FOR TUESDAY. 34
&&
.PREV DISCUSSION...332 PM MDT MON SEP 14 2015...
.SYNOPSIS...
AN UPPER LEVEL TROUGH TRAVERSING THE CENTRAL AND NORTHERN ROCKIES
FROM CALIFORNIA WILL SHOULD DRAW ENOUGH MOISTURE NORTHWARD FOR A
BRIEF UPTICK IN SHOWER AND THUNDERSTORM COVERAGE ACROSS NORTHWEST
AND WEST CENTRAL NEW MEXICO TONIGHT. PRECIPITATION CHANCES WILL
TREND DOWNWARD TUESDAY THROUGH MID WEEK AS DRIER AIR MOVES OVER
THE STATE FROM THE SOUTHWEST. A ROLLER COASTER OF TEMPERATURES IS
EXPECTED AS HIGHS FALL SOME TUESDAY...RISE A BIT MOST PLACES
THROUGH MID WEEK...THEN FALL MORE SIGNIFICANTLY FRIDAY AND
SATURDAY AS A BACK DOOR COLD FRONT PLUNGES THROUGH THE STATE.
MODEST MOISTURE ARRIVING WITH THE FRONT...AND SOME ELEVATED
MOISTURE TRAVELING NORTHWARD FROM MEXICO...SHOULD FEED BETTER
COVERAGE OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF THE
CONTINENTAL DIVIDE TO THE TEXAS BOARDER THIS WEEKEND.
&&
.DISCUSSION...
THE DRY SLOT HEADED THIS WAY THIS AFTERNOON LOOKS PRETTY
IMPRESSIVE ON WATER VAPOR IMAGERY. THE BEST CHANCE FOR SHOWERS
AND STORMS FORMING MAINLY OVER NW AREAS SHOULD BE THIS EVENING
JUST BEFORE THE DRIER AIR ALOFT ARRIVES.
A BROAD TROUGH OVER THE W COAST AND GREAT BASIN WILL DEEPEN
TUESDAY AND WEDNESDAY...FLATTENING OUT THE MID LEVEL HIGH SE OF
NEW MEXICO SO THE RIDGE AXIS CUTS OFF THE ELEVATED NORTHWARD
MOISTURE FLUX FROM MEXICO. STRENGTHENING SW FLOW ALOFT SHOULD
RESULT IN SOME FAIRLY BREEZY CONDITIONS ALONG AND NORTH OF I-40
TUESDAY AND ESPECIALLY WEDNESDAY WHEN ATMOSPHERIC MIXING WILL
IMPROVE. HIGH TEMPERATURES ACROSS THE PLAINS SHOULD VARY AROUND 5
TO 12 DEGREES ABOVE NORMAL TUESDAY THROUGH THURSDAY.
TEMPERATURES WILL THEN TREND DOWNWARD WITH THE BACK DOOR FRONT...AND
MOISTURE WILL IMPROVE ACROSS CENTRAL AND EASTERN AREAS AT THE END
OF THE WEEK. MODEL QPF FIELDS LOOK PRETTY LIGHT...SO RAIN AMOUNTS
THIS WEEKEND SHOULD GENERALLY BE LIGHT...THOUGH THE COVERAGE
INCREASE SHOULD BE NOTABLE. 44
&&
.FIRE WEATHER...
MODERATE INCREASE IN MOISTURE UNDERWAY ACROSS ROUGHLY THE NW THIRD
OF NM...LESS SO ACROSS THE REST OF THE STATE. ISOLATED TO...AT
TIMES...SCATTERED SHOWERS AND STORMS ACROSS MAINLY THE NW THIRD OF
NM THIS AFTN AND INTO MID EVE SHOULD DIMINISH TO A LARGE DEGREE
THEREAFTER...LEAVING A FEW LINGERING LIGHT SHOWERS. WHILE A FEW
SPOTS SHOULD SEE SOME LOW END WETTING RAINFALL...MAJORITY OF LOCALES
WILL NOT. RH RECOVERIES SHOULD BE AT LEAST A LITTLE BETTER ACROSS NW
HALF OF FCST AREA TONIGHT VERSUS SUN NIGHT. A FEW SPOTS ACROSS THE
EASTERN PLAINS MAY SEE AN HOUR OR TWO OF VERY LOW END CRITICAL FIRE
WEATHER CONDITIONS DUE TO WINDS AND LOW RH BETWEEN MID AND LATE AFTN
TODAY.
WINDS ALOFT EXPECTED TO PICK UP A BIT MORE TUE OVER MOST OF FCST
AREA AS SOMEWHAT DRIER AIR INVADES. WIND DIRECTION WILL REMAIN
SOUTHWESTERLY ACROSS THE FORECAST AREA INTO TUE...BUT SPEEDS WILL
RAMP UP A BIT...IN THE VICINITY OF 20 TO 25 MPH IN SOME NORTHEASTERN
AND NORTHWESTERN ZONES AND HIGHER TERRAIN OF N CENTRAL NM. WHILE
WINDS WILL LIKELY REACH AT LEAST LOW END CRITICAL THRESHOLDS...RH
VALUES ARE EXPECTED TO GENERALLY HOVER IN THE 18 TO JUST OVER 30
PERCENT RANGE...A BIT HIGHER THAN THE CRITICAL THRESHOLD OF 15
PERCENT. AFTN TEMPS TO BE NEAR TO SLIGHTLY LOWER THAN TODAY AND WHAT
FEW SHOWERS AND STORMS DO DEVELOP...FEWER THAN TODAY...WILL AGAIN BE
MAINLY IN THE WEST CENTRAL TO NW AND NORTH CENTRAL ZONES.
WED AND THU WILL BRING EVEN A LITTLE MORE DRYING AND EVEN FEWER...IF
ANY...WETTING RAIN CHANCES. WIND SPEEDS ALOFT WILL PERHAPS DECLINE
JUST A BIT...BUT BREEZY TO LOW END WINDY CONDITIONS LIKELY TO RETURN
AT THE SURFACE AND 20FT LEVEL IN MANY NORTH AND EASTERN ZONES WED
AFTN AND LIKELY A BIT LESS THU AFTN. RH MAY TREND DOWN JUST A BIT
FURTHER ACROSS A GOOD PART OF THE STATE WED AFTN AND IT IS NOT OUT
OF THE QUESTION THAT A FEW SPOTS ACROSS MAINLY EAST CENTRAL AND NE
NM MAY APPROACH OR EVEN BRIEFLY REACH LOW END CRITICAL FIRE WX
CONDITIONS. THIS WILL BE MONITORED CLOSELY FOR ANY DRYING GREATER
THAN CURRENTLY EXPECTED.
THE PREVIOUSLY MODEL FORECASTED SHOWER AND STORM UPTICK DURING AND A
BIT EITHER SIDE OF THE WEEKEND NOW LOOKS TO BE MORE RESTRICTED IN
TIME AND A LITTLE LESS ROBUST THAN PREVIOUSLY ADVERTISED...ESPEC IN
THE NW THIRD TO HALF OF THE STATE. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
418 AM CDT TUE SEP 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE MAIN FOCUS FOR THE SHORT TERM WILL BE THUNDERSTORM CHANCES.
A SURFACE LOW WILL CONTINUE TO PUSH OUT OF EASTERN MONTANA AND
INTO WESTERN NORTH DAKOTA TODAY...DRAGGING WITH IT A WARM FRONT
ACROSS THE REGION. SCATTERED SHOWERS ARE POSSIBLE ALONG THE WARM
FRONT THIS MORNING. BY THIS AFTERNOON MOST OF WESTERN AND CENTRAL
NORTH DAKOTA WILL BE IN THE WARM SECTOR. TEMPERATURES ARE EXPECTED
TO RISE INTO THE MID TO UPPER 80S ACROSS MOST OF THE REGION.
STRONG MOISTURE ADVECTION WILL OCCUR AT THE SURFACE WITH DEWPOINTS
IN THE MID 60S LIKELY. HOWEVER...RELATIVELY WARM AND DRY MID-
LEVELS (AS SEEN IN RAP AND NAM FORECAST SOUNDINGS) COULD LIMIT
AFTERNOON CONVECTION. IF THUNDERSTORMS DO DEVELOP THIS
AFTERNOON...THEY COULD BECOME STRONG WITH GUSTY WINDS AND SMALL
HAIL...WITH CAPE AROUND 1000 J/KG...30+ KNOTS OF SHEAR AND STEEP
LAPSE RATES FORECAST. THIS EVENING WILL SEE THE BEST CHANCE FOR
THUNDERSTORMS WHEN UPPER LEVEL SUPPORT ARRIVES VIA A SHORT WAVE
TROUGH AND JET STREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE EXTENDED BEGINS WEDNESDAY AND FEATURES A LONGWAVE TROUGH OVER
THE WESTERN US WITH A DOWNSTREAM BROAD RIDGE OVER THE GREAT
LAKES. THIS PLACES THE NORTHERN PLAINS IN A SOUTHWEST FLOW REGIME
ALOFT THAT WILL BRING SHORTWAVE ENERGY INTO THE NORTHERN PLAINS
BY WEDNESDAY NIGHT AND THURSDAY. THIS WILL END UP BEING THE MOST
ACTIVE PERIOD FOR THUNDERSTORMS. AFTER THE TROUGH AXIS MOVES
THROUGH A SECOND SHORTWAVE WILL BRUSH THE SOUTHERN SECTIONS OF THE
STATEON FRIDAY. OTHERWISE A DRY PERIOD WITH GRADUAL MODERATING
TEMPERATURES WILL TAKE HOLD FOR THE WEEKEND.
MODELS APPEAR IN GOOD AGREEMENT ON THESE GENERAL FEATURES. A COLD
FRONT ASSOCIATED WITH THE SHORT WAVE WILL MOVE ACROSS THE STATE
WEDNESDAY AND WEDNESDAY NIGHT AND BE THE FOCUS FOR THUNDERSTORMS.
COOLER AIR BEHIND THE FRONT THURSDAY WILL MEAN HIGHS ONLY IN THE
UPPER 50S NORTH TO THE 70S SOUTHEAST. THE BEST CHANCE FOR
PRECIPITATION WILL BE ACROSS THE NORTH WITH LIKELY TO DEFINITE
POPS BY WEDNEDAY NIGHT. LINGERING SHOWERS WILL REMAIN ACROSS THE
NORTH AND EAST THURSDAY. CLEARING SKIES WITH A SLOW MODERATION IN
TEMPERATURES FOR THE WEEKEND THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1220 AM CDT TUE SEP 15 2015
VFR TO MVFR CONDITIONS ARE EXPECTED AT KISN/KDIK/KMOT THROUGH THE
TAF PERIOD. SOME LOWER CIGS AND VSBY ARE POSSIBLE AT KBIS/KJMS
EARLY THIS MORNING WITH POTENTIAL FOG AND STRATUS DEVELOPMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...WAA
AVIATION...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
410 AM CDT TUE SEP 15 2015
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 410 AM CDT TUE SEP 15 2015
ALREADY ADDED TSRA TO PARTS OF CENTRAL AND EAST CENTRAL WISCONSIN
AN HOUR AGO BUT RADAR TRENDS SHOW A SMALL CLUSTER OF CONVECTION
OVER SOUTHERN PORTIONS OF MTW AND CALUMET COUNTIES WITH A
DEPARTING VORT AND THEN A SECOND AREA WITHE WAA PCPN WITH THE LLJ
STILL WORKING INTO CENTRAL WISCONSIN. NO RECENT LIGHTNING STRIKES
OVER CENTRAL WI BUT CONVECTION WAS SHOWING A GRADUAL DECREASE.
THE CONVECTION WAS ELEVATED.
&&
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
OVERALL DRY QUIET AND ABOVE NORMAL TEMPERATURES THROUGH MID WEEK.
EARLY THIS MORNING ISOLATED TO SCATTERED CONVECTION WAS OCCURRING
IN THE BROAD WAA SECTOR FROM SOUTHERN MINNESOTA TO THE SOUTH HALF
OF WISCONSIN. CONVECTION OVER WESTERN WISCONSIN PRIMARILY WARM
AIR ADVECTION WITH THE STRONGER LLJ...WHILE CONVECTION CENTERED
AROUND FOND DU LAC COUNTY ASSOCIATED WITH A WEAK VORT SLIDING OVER AS
PER WATER VAPOR LOOP EARLY THIS MORNING. HRRR MODEL SLIDE WEAK
CONVECTION OVER THE SOUTHERN TWO THIRDS OF THE FORECAST AREA EARLY
THIS MORNING. WILL KEEP THE ISOLD SPRINKLES GOING THIS MORNING DUE
TO FALLING FROM MID LEVEL CLOUDS BUT MONITOR FOR ANY NEEDED
MENTION OF TSRA TO THE AREA TO AROUND DAYBREAK. CONVECTION
EXPECTED TO DISSIPATE LATER MORNING AS THE VORT SLIDES EAST AND
THE WARM AIR ADVECTION MIXES OUT TO PROVIDE AN OVERALL DRY DAY.
LITTLE CHANGED IN THE FORECAST FOR TONIGHT...CONTINUED WAA IN THE
SOUTHWEST FLOW AND LLJ WILL BRING A SMALL CHANCE OF CONVECTION TO
THE NORTHWEST HALF TONIGHT. WHAT CONVECTION DEVELOPS TUESDAY
NIGHT WILL TAPER OFF AGAIN WEDNESDAY MORNING FOR ANOTHER MILD
SEPTEMBER DAY WEDNESDAY. A LITTLE MORE MID TO UPPER CLOUDS MAY
FILTER INTO NORTH CENTRAL WISCONSIN LATER WEDNESDAY AS A NORTHERN
PLAINS FRONTAL SYSTEM VERY SLOWLY APPROACHES THE REGION.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
MAIN FCST SYSTEM OF INTEREST TO BE THE MOVEMENT OF A SHORTWAVE
TROF FROM THE WEST COAST MID-WEEK...TO THE GREAT LAKES AT THE END
OF THE WEEK. WARM/INCREASINGLY MORE HUMID AIR MASS TO PUSH INTO WI
AHEAD OF THIS APPROACHING UPR TROF WHICH WL LEAD TO AN UNSETTLED
WEATHER PERIOD FROM WED NGT THRU FRI NGT. THE MEAN FLOW TURNS
ZONAL FOR EARLY NEXT WEEK WITH DRIER/COOLER AIR MASS SPREADING
OVER THE REGION.
PREVAILING SW WIND WL CONT INTO THE WRN GREAT LAKES WED NGT WITH
WAA AND A SHORTWAVE HEADED TOWARD NE WI. ENUF MOISTURE MAY BE
PRESENT TO BRING AT LEAST A SMALL CHC OF SHWRS/TSTMS TOWARD CNTRL
WI...ESPECIALLY AFTER MIDNGT. OTHERWISE...CLOUDS SHOULD CONT TO
INCREASE/THICKEN THRU THE NGT WITH MIN TEMPS MAINLY IN THE LWR TO
MID 60S. A STRONG AREA OF LOW PRES IS FCST TO MOVE FROM THE NRN
PLAINS NEWD INTO SW ONTARIO ON THU AND PULL A CDFNT EWD TOWARD THE
MN/WI BORDER BY 00Z FRI. THE STRONGER MID-LEVEL FORCING IS
ADVERTISED BY THE MODELS TO REMAIN NEAR THE SFC LOW...THEREBY
LEAVING THE CDFNT AS THE MAIN TRIGGER FOR PCPN DEVELOPMENT. SINCE
THE FRONT IS STILL WELL TO OUR WEST...IT MAY BE DIFFICULT FOR PCPN
TO PUSH TOO FAR EWD. WL CONT TO FOCUS HIGHER POPS OVER CNTRL WI...
BUT MAY TRIM VALUES A BIT. ANOTHER WARM DAY IS EXPECTED WITH MAX
TEMPS IN THE MID TO UPR 70S NORTH/LAKESHORE...AROUND 80 DEGS
SOUTH.
MODELS SEND THE CDFNT INTO ERN WI THU NGT (GFS A TAD FASTER)...
ACCOMPANIED BY SEVERAL SHORTWAVES MOVING NEWD THRU THE MEAN SW
FLWO ALOFT. PREVIOUS SHIFT ALREADY HAD LIKELY POPS ACROSS THE
ENTIRE FCST AREA WHICH STILL LOOKS VALID AT THIS TIME. IF THERE IS
A QUESTION...IT IS THE SPEED OF THE CDFNT AND WHETHER SHWR/TSTM
ACTIVITY WL BEGIN TO DIMINISH OVER CNTRL WI LATE THU NGT. MAY END
UP SPLITTING THE POP GRID AND SHOW A DIMINISHING TREND IN THE POPS
FOR CNTRL WI. MIN TEMPS TO RANGE FROM THE MID TO UPR 50S
N-CNTRL...LWR 60S E-CNTRL WI. FRI`S FCST IS A BIT TRICKY AS THE
MODELS INDICATE A SFC WAVE TO DEVELOP ON THE TAIL OF THE CDFNT AND
MOVE NE TOWARD THE MID-MS VALLEY. MEANWHILE...THE SHORTWAVE TROF
WL BE SWEEPING EWD ACROSS THE NRN PLAINS WITH VARIOUS SHORTWAVES
EMBEDDED WITHIN THE TROF. ANY BREAK IN THE PCPN CHCS APPEAR SHORT-
LIVED AS SHWRS/TSTMS CONVERGE ON WI...ESPECIALLY BY FRI AFTERNOON.
MAY NEED TO TWEAK POPS UP A BIT AS A RESULT. MAX TEMPS TO COOL A
LITTLE FROM PREVIOUS DAYS WITH READINGS IN THE MID TO UPR 60S
N-CNTRL...LWR TO MID 70S E-CNTRL WI.
THE SFC WAVE AND SHORTWAVE TROF CONVERGE ON THE GREAT LAKES FRI
NGT WHICH SHOULD BRING A GOOD CHC FOR ADDITIONAL SHWRS/TSTMS TO NE
WI. THE BACK EDGE OF ANY LINGERING SHWRS MAY AFFECT ERN WI INTO
SAT MORNING...OTHERWISE HI PRES IS FCST TO BUILD ACROSS THE
MIDWEST AND BRING INCREASING SUNSHINE TO THE REGION FOR A GOOD
PART OF SAT. MAX TEMPS SHOULD BE CLOSE TO NORMAL WITH READINGS IN
THE MID 60S TO AROUND 70S DEGS. THIS AREA OF HI PRES TO LIFT NE
INTO THE GREAT LAKES FOR THE LATTER HALF OF THE WEEKEND...THEREBY
BRINGING QUIET WEATHER CONDITIONS TO NE WI WITH TEMPS HOLDING
SLIGHTLY ABOVE NORMAL. A RETURN FLOW DEVELOPS OVER WI BY NEXT MON
WITH WINDS BECOMING S-SW. NO TRIGGER IS EVIDENT...THUS NO PCPN
ANTICIPATED THRU MON. TEMPS ON MON MAY ADD A COUPLE OF DEGS FROM
SUNDAY WITH MOST LOCATIONS IN THE UPR 60S TO LWR 70S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1032 PM CDT MON SEP 14 2015
VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY
NIGHT. VWP SHOWS LLWS HAD DEVELOPED TONIGHT AND IS EXPECTED TO
CONTINUE THROUGH 15Z TUESDAY FROM WINDS FROM 230-240 DEGREES AT
35 TO 40 KNOTS. A FEW SPRINKLES ARE POSSIBLE FROM A MID DECK OF
CLOUDS LATE TONIGHT AND EARLY TUESDAY MORNING SOUTH OF HIGHWAY 29.
HOWEVER THE PROBABILITY IS NOT HIGH ENOUGH TO PUT IN THE TAFS
WITH THIS ISSUANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......KURIMSKI
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
OVERALL DRY QUIET AND ABOVE NORMAL TEMPERATURES THROUGH MID WEEK.
EARLY THIS MORNING ISOLATED TO SCATTERED CONVECTION WAS OCCURRING
IN THE BROAD WAA SECTOR FROM SOUTHERN MINNESOTA TO THE SOUTH HALF
OF WISCONSIN. CONVECTION OVER WESTERN WISCONSIN PRIMARILY WARM
AIR ADVECTION WITH THE STRONGER LLJ...WHILE CONVECTION CENTERED
AROUND FOND DU LAC COUNTY ASSOCIATED WITH A WEAK VORT SLIDING OVER AS
PER WATER VAPOR LOOP EARLY THIS MORNING. HRRR MODEL SLIDE WEAK
CONVECTION OVER THE SOUTHERN TWO THIRDS OF THE FORECAST AREA EARLY
THIS MORNING. WILL KEEP THE ISOLD SPRINKLES GOING THIS MORNING DUE
TO FALLING FROM MID LEVEL CLOUDS BUT MONITOR FOR ANY NEEDED
MENTION OF TSRA TO THE AREA TO AROUND DAYBREAK. CONVECTION
EXPECTED TO DISSIPATE LATER MORNING AS THE VORT SLIDES EAST AND
THE WARM AIR ADVECTION MIXES OUT TO PROVIDE AN OVERALL DRY DAY.
LITTLE CHANGED IN THE FORECAST FOR TONIGHT...CONTINUED WAA IN THE
SOUTHWEST FLOW AND LLJ WILL BRING A SMALL CHANCE OF CONVECTION TO
THE NORTHWEST HALF TONIGHT. WHAT CONVECTION DEVELOPS TUESDAY
NIGHT WILL TAPER OFF AGAIN WEDNESDAY MORNING FOR ANOTHER MILD
SEPTEMBER DAY WEDNESDAY. A LITTLE MORE MID TO UPPER CLOUDS MAY
FILTER INTO NORTH CENTRAL WISCONSIN LATER WEDNESDAY AS A NORTHERN
PLAINS FRONTAL SYSTEM VERY SLOWLY APPROACHES THE REGION.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
MAIN FCST SYSTEM OF INTEREST TO BE THE MOVEMENT OF A SHORTWAVE
TROF FROM THE WEST COAST MID-WEEK...TO THE GREAT LAKES AT THE END
OF THE WEEK. WARM/INCREASINGLY MORE HUMID AIR MASS TO PUSH INTO WI
AHEAD OF THIS APPROACHING UPR TROF WHICH WL LEAD TO AN UNSETTLED
WEATHER PERIOD FROM WED NGT THRU FRI NGT. THE MEAN FLOW TURNS
ZONAL FOR EARLY NEXT WEEK WITH DRIER/COOLER AIR MASS SPREADING
OVER THE REGION.
PREVAILING SW WIND WL CONT INTO THE WRN GREAT LAKES WED NGT WITH
WAA AND A SHORTWAVE HEADED TOWARD NE WI. ENUF MOISTURE MAY BE
PRESENT TO BRING AT LEAST A SMALL CHC OF SHWRS/TSTMS TOWARD CNTRL
WI...ESPECIALLY AFTER MIDNGT. OTHERWISE...CLOUDS SHOULD CONT TO
INCREASE/THICKEN THRU THE NGT WITH MIN TEMPS MAINLY IN THE LWR TO
MID 60S. A STRONG AREA OF LOW PRES IS FCST TO MOVE FROM THE NRN
PLAINS NEWD INTO SW ONTARIO ON THU AND PULL A CDFNT EWD TOWARD THE
MN/WI BORDER BY 00Z FRI. THE STRONGER MID-LEVEL FORCING IS
ADVERTISED BY THE MODELS TO REMAIN NEAR THE SFC LOW...THEREBY
LEAVING THE CDFNT AS THE MAIN TRIGGER FOR PCPN DEVELOPMENT. SINCE
THE FRONT IS STILL WELL TO OUR WEST...IT MAY BE DIFFICULT FOR PCPN
TO PUSH TOO FAR EWD. WL CONT TO FOCUS HIGHER POPS OVER CNTRL WI...
BUT MAY TRIM VALUES A BIT. ANOTHER WARM DAY IS EXPECTED WITH MAX
TEMPS IN THE MID TO UPR 70S NORTH/LAKESHORE...AROUND 80 DEGS
SOUTH.
MODELS SEND THE CDFNT INTO ERN WI THU NGT (GFS A TAD FASTER)...
ACCOMPANIED BY SEVERAL SHORTWAVES MOVING NEWD THRU THE MEAN SW
FLWO ALOFT. PREVIOUS SHIFT ALREADY HAD LIKELY POPS ACROSS THE
ENTIRE FCST AREA WHICH STILL LOOKS VALID AT THIS TIME. IF THERE IS
A QUESTION...IT IS THE SPEED OF THE CDFNT AND WHETHER SHWR/TSTM
ACTIVITY WL BEGIN TO DIMINISH OVER CNTRL WI LATE THU NGT. MAY END
UP SPLITTING THE POP GRID AND SHOW A DIMINISHING TREND IN THE POPS
FOR CNTRL WI. MIN TEMPS TO RANGE FROM THE MID TO UPR 50S
N-CNTRL...LWR 60S E-CNTRL WI. FRI`S FCST IS A BIT TRICKY AS THE
MODELS INDICATE A SFC WAVE TO DEVELOP ON THE TAIL OF THE CDFNT AND
MOVE NE TOWARD THE MID-MS VALLEY. MEANWHILE...THE SHORTWAVE TROF
WL BE SWEEPING EWD ACROSS THE NRN PLAINS WITH VARIOUS SHORTWAVES
EMBEDDED WITHIN THE TROF. ANY BREAK IN THE PCPN CHCS APPEAR SHORT-
LIVED AS SHWRS/TSTMS CONVERGE ON WI...ESPECIALLY BY FRI AFTERNOON.
MAY NEED TO TWEAK POPS UP A BIT AS A RESULT. MAX TEMPS TO COOL A
LITTLE FROM PREVIOUS DAYS WITH READINGS IN THE MID TO UPR 60S
N-CNTRL...LWR TO MID 70S E-CNTRL WI.
THE SFC WAVE AND SHORTWAVE TROF CONVERGE ON THE GREAT LAKES FRI
NGT WHICH SHOULD BRING A GOOD CHC FOR ADDITIONAL SHWRS/TSTMS TO NE
WI. THE BACK EDGE OF ANY LINGERING SHWRS MAY AFFECT ERN WI INTO
SAT MORNING...OTHERWISE HI PRES IS FCST TO BUILD ACROSS THE
MIDWEST AND BRING INCREASING SUNSHINE TO THE REGION FOR A GOOD
PART OF SAT. MAX TEMPS SHOULD BE CLOSE TO NORMAL WITH READINGS IN
THE MID 60S TO AROUND 70S DEGS. THIS AREA OF HI PRES TO LIFT NE
INTO THE GREAT LAKES FOR THE LATTER HALF OF THE WEEKEND...THEREBY
BRINGING QUIET WEATHER CONDITIONS TO NE WI WITH TEMPS HOLDING
SLIGHTLY ABOVE NORMAL. A RETURN FLOW DEVELOPS OVER WI BY NEXT MON
WITH WINDS BECOMING S-SW. NO TRIGGER IS EVIDENT...THUS NO PCPN
ANTICIPATED THRU MON. TEMPS ON MON MAY ADD A COUPLE OF DEGS FROM
SUNDAY WITH MOST LOCATIONS IN THE UPR 60S TO LWR 70S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1032 PM CDT MON SEP 14 2015
VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY
NIGHT. VWP SHOWS LLWS HAD DEVELOPED TONIGHT AND IS EXPECTED TO
CONTINUE THROUGH 15Z TUESDAY FROM WINDS FROM 230-240 DEGREES AT
35 TO 40 KNOTS. A FEW SPRINKLES ARE POSSIBLE FROM A MID DECK OF
CLOUDS LATE TONIGHT AND EARLY TUESDAY MORNING SOUTH OF HIGHWAY 29.
HOWEVER THE PROBABILITY IS NOT HIGH ENOUGH TO PUT IN THE TAFS
WITH THIS ISSUANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
945 AM EDT TUE SEP 15 2015
.UPDATE...
...LOCALLY HEAVY RAINFALL POSSIBLE FOR MID TO LATE WEEK...
CURRENT...SHOWERS MOVING NORTHWEST AT AROUND 15 MPH OVER THE COASTAL
WATERS. THE FORT PIERCE AREA ALREADY HAS HAD SHOWERS COME ASHORE AND
WERE MOVING INLAND WEST OF INTERSTATE 95. MORE SHOWERS BEYOND 20
MILES OF SHORE BETWEEN SAINT LUCIE AND SEBASTIAN INLETS SHOULD BE
NEARING THE COAST LATE MORNING. MORE SHOWERS EXPECTED TO COME ASHORE
BETWEEN CAPE CANAVERAL AND THE ORMOND BEACH/FLAGLER BEACH AREA THIS
MORNING.
THE VERTICAL WIND PROFILERS AT KENNEDY SPACE CENTER SHOW A DEEP
LAYER EAST SOUTHEAST FLOW AROUND 15 MPH TO 10,000 FEET. THE 8AM/12Z
CAPE CANAVERAL SOUNDING ANALYZED A PRECIPITABLE WATER VALUE OF
AROUND 1.95 INCHES.
REST OF TODAY...DEEP LAYER MOISTURE WITH WINDS AROUND 15 MPH WILL
CONTINUE THE REST OF THE DAY PER THE LATEST RAP40 AND GFS20 TIME
HEIGHT CROSS SECTIONS. THE SHOWERS OVER THE OCEAN THAT COME ASHORE
AND IMPACT THE COASTAL COUNTIES THROUGH MID MORNING LOOK TO BE MORE
OF THE CYCLONIC CONVERGENT BAND TYPE. THIS AFTERNOONS SHOWERS SHOULD
TRANSITION TO STORMS WITH DAYTIME HEATING ONCE THEY GET INTO THE
INTERIOR LATER TODAY.
THE CURRENT PROGRESSION OF ISOLATED SHOWERS/STORMS AT THE COAST THIS
MORNING BECOMING SCATTERED SHOWERS/ISOLATED STORMS OVER THE INTERIOR
THIS AFTERNOON LOOKS GOOD.
MORNING UPDATE MAINLY FOR THE VARIOUS WIND GRIDS.
&&
.AVIATION...MADE SOME EARLY AMD`S FOR TEMPO MVFR CIGS/VSBYS @FPR/VRB
DUE TO CLUSTER OF SHRA NOW PUSHING NW OF THERE. THE 12Z TAF PACKAGE
OPTED FOR VCSH/VCTS SHIFTING INLAND THIS AFTN. STRONGLY SUSPECT THAT
THERE WILL BE A FEW MORE AMDS FROM 16Z ONWARD AND MAY ALSO NEED SOME
TEMPO GROUPS FOR THE 18Z PACKAGE FOR ONE OR MORE OF THE INLAND
AERODROMES.
&&
.MARINE...
THE NOAA BUOYS AND CMAN BUOYS WERE RECORDING NORTHEAST TO EAST WINDS
5 TO 10 KNOTS AND 1 TO 3 FOOT SEAS OUT TO BUOY 009 AT 20NM EAST OF
CAPE CANAVERAL. THE TWO SCRIPPS BUOYS AT 4 AND 6NM OFF THE COAST
WERE RECORDING 2 TO 3 FOOT SEAS.
WAVE WATCH MODEL INDICATING THAT THE SEAS WILL SLOWLY INCREASE
STARTING TODAY AS A BUILDING SWELL COMPONENT PROPAGATES INTO THE
COASTAL WATERS.
THE CURRENT AFTERNOON MARINE FORECAST OF 4 FOOT SEAS BEYOND 20 MILES
OF SHORE LOOKS GOOD.
THE LONGER PERIODS OF THE BUILDING SWELL COMPONENT AND THE TIME OF
THE HIGH TIDES GOING FROM MID MORNING TO NOON/EARLY AFTERNOON
SHOULD IMPACT THE RIP RISK AT AREA BEACHES THE REST OF THE WEEK AND
INTO THE WEEKEND.
&&
PUBLIC/GRIDDED FORECASTS...WIMMER
AVIATION/RADAR/IMPACT WX...CRISTALDI
&&
.PREV DISCUSSION... /ISSUED 344 AM EDT TUE SEP 15 2015/
TODAY-TONIGHT... CLOCKWISE FLOW AROUND A SPRAWLING AREA OF HIGH
PRESSURE TO OUR NORTH WILL MAINTAIN EASTERLY FLOW TODAY. TO OUR
SOUTH...A TROUGH AXIS ASSOCIATED WITH THE REMNANTS OF T.C. GRACE
WILL MOVE THROUGH THE FLORIDA STRAITS WHILE A DECAYING FRONTAL
BOUNDARY MEANDERS OVER SOUTH FLORIDA.
LATEST RAP ANALYSIS INDICATES A COLUMN THAT IS SLOWLY
MOISTENING...THOUGH SOME MID LEVEL DRY AIR LINGERS ACROSS OUR
NORTHWESTERN AREAS. AS INDICATED BY THE CAPE WIND PROFILERS...LOW
LEVEL EASTERLY FLOW IS PRESENT FROM THE SURFACE THROUGH ABOUT 4000
FEET...AND PERHAPS A LITTLE DEEPER THESE LAST FEW HOURS. EXPECT
SCATTERED SHOWERS AND ISOLATED STORMS OVER THE SE COASTAL WATERS TO
SPREAD TO THE NORTH AND WEST THIS MORNING AS DEEPER MOISTURE MOVES
IN. THESE SHOWERS COMBINED WITH DIURNAL HEATING WILL PROVIDE A
CHANCE FOR SHOWERS AND STORMS ALONG THE COAST THROUGH EARLY THIS
AFTERNOON. EXPECT THE ATLANTIC SEA BREEZE...ALBEIT DIFFUSE...TO MOVE
INLAND AND ACT AS A FOCUS FOR ADDITIONAL STORM DEVELOPMENT OVER THE
INTERIOR THIS AFTERNOON. CANNOT RULE OUT ADDITIONAL SHOWERS AND
PERHAPS A STORM MOVING ONSHORE GIVEN THE LOW-LEVEL EASTERLY FLOW.
STEERING LAYER FLOW...850-700MB...APPEARS WEAK AGAIN
TODAY...ESPECIALLY NORTH OF THE TREASURE COAST SO WILL NEED TO WATCH
FOR SLOW MOVING DOWNPOURS.
DIURNALLY DRIVEN CONVECTION SHIFTS TO THE WEST COAST AFTER SUNSET
BEFORE FOCUS SHIFTS BACK TO THE ATLANTIC. MAINTAINED SCATTERED POPS
OVERNIGHT ALONG THE COAST FOR NOCTURNAL ACTIVITY OVER THE ATLANTIC.
WED...THE LOW LEVEL EASTERLY WAVE WILL MOVE SLOWLY WESTWARD TOWARD
THE SE/S CENTRAL GULF OF MEXICO WITH DEEP MOISTURE INCREASING IN THE
STRENGTHENING LOW LEVEL EASTERLY FLOW. A MID LVL TROUGH WILL MOVE
EASTWARD TOWARD THE ERN GULF AND INCREASE THE DEEP LAYER MOISTURE IN
THE H7-H3 LAYER OVER MUCH OF THE FL PENINSULA. LIKELY SHOWER CHANCES
ARE EXPECTED WITH A CHANCE OF STORMS ESPEC IN THE AFTERNOON. A
TIGHTENING PRESSURE GRADIENT WILL SUPPORT ENE/NE WINDS AT 10-15 MPH
WITH MAINLY CLOUDY SKIES. CONVERGENT SHOWERS BANDS WILL MOVE ONSHORE
AND PUSH INTO THE INTERIOR THROUGH THE DAY. PRECIPITABLE WATER
VALUES WILL INCREASE TO 2.0-2.1 INCHES INTO LATE AFTERNOON WITH
LOCALLY HEAVY RAINFALL POSSIBLE WITH ANY TRAINING RAIN BANDS THAT
MOVE ONSHORE.
WED NIGHT...THE EASTERLY WAVE SHOULD SHARPEN OVER THE GULF WITH
NUMEROUS SHOWERS CONTINUING ACROSS E CENTRAL FL. DEEP MOISTURE AND
SUPPORT FROM THE MID LVL TROUGH TO THE WEST SHOULD ALLOW FOR
ADDITIONAL SHOWERS TO DEVELOP THROUGH THE NIGHT AND ALSO MOVE
ONSHORE. MAINLY CLOUDY SKIES ARE EXPECTED WITH LOWS IN THE LOWER TO
MID 70S.
THU...00Z GFS PINCHES OFF A WEAK SFC LOW IN THE GULF ON THU WITH THE
NAM EVEN DEEPER WITH SFC DEVELOPMENT. OVERALL PATTERN WITH DEEP
MOISTURE...LOW LVL E/SE FLOW AND THE MID/UPR LVL TROUGH ACROSS THE
GULF WILL CONTINUE NUMEROUS SHOWERS AND THE CHANCE FOR STORMS.
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH PRECIPITABLE WATER
VALUES FROM 2.1-2.3 INCHES.
FRIDAY...LIKELY SHOWER/THUNDERSTORM CHANCES ARE EXPECTED AGAIN WITH
LITTLE MOVEMENT TO THE LOW IN THE GULF AND THE UPPER LVL TROUGH
STILL WEST OF THE AREA. 00Z GFS INDICATES A PIECE OF MID LVL SUPPORT
MAY EJECT TOWARD THE CENTRAL PENINSULA WITH DEEP MOISTURE
CONTINUING. ANOTHER MOSTLY CLOUDY DAY WITH THE RISK OF LOCALLY HEAVY
RAINFALL WITH SHOWERS AND STORMS IN THE AFTERNOON.
SAT-TUE...APPEARS THE MID LVL WAVE WILL PASS EAST OF THE AREA OVER
THE WEEKEND INTO EARLY NEXT WEEK WITH DEEP MOISTURE BEING SHUNTED
EAST OF THE PENINSULA BY SUNDAY INTO MONDAY. CONSENSUS POPS DROP TO
THE SCATTERED RANGE WHICH SEEMS REASONABLE GIVEN SOME DRYING ON THE
BACK SIDE OF THE MID LVL TROUGH AND LOW LVL WINDS SWITCHING TO THE
N/NE. SHOULD SEE MORE SUN TO THE END THE WEEK AND THE FIRST PART OF
NEXT WEEK. HIGHS EXPECTED IN THE UPPER 80S WITH LOW IN THE LOWER-MID
70S.
&&
.AVIATION... SCATTERED SHRA AND ISOLATED TSRA EXPECTED
TODAY...INITIALLY ALONG THE COAST SOUTH OF KTIX...THEN SPREADING
INLAND IN LOW LEVEL EASTERLY FLOW. CANNOT RULE OUT ISOLATED SHRA AND
TSRA ALONG THE COAST THROUGH THE DAY. LOWER EXPECTED COVERAGE AND
TIMING UNCERTAINTIES PREVENT THE ADDITION OF TEMPO GROUPS FOR
NOW...AND WILL PROVIDE AMENDMENTS AS NECESSARY BASED ON RADAR TRENDS.
&&
.MARINE... CLOCKWISE FLOW AROUND A SPRAWLING AREA OF HIGH PRESSURE
ON THE EAST COAST WILL MAINTAIN A GENTLE TO MODERATE BREEZE OVER THE
ATLANTIC WATERS. SEAS UP TO 4 FEET WITH A SHORT 5 TO 6 SECOND PERIOD
WILL MAKE CONDITIONS ROUGH OVER THE OPEN WATERS. LOCAL PRESSURE
GRADIENT WILL SUPPORT 10 TO 15 KNOTS...THOUGH AT TIMES
HIGHER...THROUGH TONIGHT. WIND AND SEAS WILL BE LOCALLY HIGHER IN
WESTWARD MOVING SCATTERED SHOWERS AND STORMS.
EAST WINDS ARE EXPECTED AROUND 15 KNOTS WED-THU WITH SEAS BUILDING
TO AROUND 4 FT. DECREASING WINDS AND SEAS ARE EXPECTED BY SATURDAY
AND SUNDAY WITH NE WINDS EXPECTED SUNDAY AS LOW PRESSURE MOVES EAST
OF THE AREA. NUMEROUS SHOWERS AND SCATTERED STORMS ARE EXPECTED
ACROSS THE WATERS WED-FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 85 76 85 74 / 50 30 60 60
MCO 89 76 86 74 / 40 20 60 60
MLB 86 78 86 75 / 50 30 60 60
VRB 87 78 85 75 / 40 30 60 60
LEE 89 75 87 71 / 40 20 60 60
SFB 87 76 87 73 / 40 20 60 60
ORL 88 76 87 73 / 40 20 60 60
FPR 88 77 86 76 / 40 30 60 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
650 AM CDT TUE SEP 15 2015
.SHORT TERM /TODAY/...
ISSUED AT 357 AM CDT TUE SEP 15 2015
COUPLE OF CHALLENGES IN THE SHORT TERM TODAY. HIGH PRESSURE REMAINS
STRONG ALOFT...OVER THE SOUTHEAST US WHILE LOW PRESSURE CONTINUES TO
ADVANCE INTO THE PLAINS. THE NET RESULT HAS BEEN A RATHER
NARROW...BUT WELL DEFINED MOISTURE RIBBON EXTENDING FROM THE GULF TO
NEARLY THE US CANADIAN BORDER. ALONG WITH THAT...SHORT WAVES AND
POCKETS OF STRONGER WARM AIR ADVECTION HAVE BEEN PASSING THROUGH THE
FLOW WITH WEAK ROUNDS OF SHOWERS/ISO THUNDER INITIATION. TODAY WILL
BE SIMILAR WITH THE POSSIBILITY OF SOME LATE MORNING/TO MID
AFTERNOON SHOWERS/THUNDERSTORMS MAINLY OVER THE WEST/NORTHWEST. ANY
STORMS THAT DO DEVELOP WILL BE ROOTED WELL ABOVE THE BOUNDARY LAYER
AND ELEVATED THROUGHOUT THE AFTERNOON. WINDS WILL BE QUITE STRONG
TODAY...ESPECIALLY ACROSS THE NORTH/NORTHWEST WHERE AMBIENT FLOW MAY
APPROACH 30 MPH WITH GUSTS OVER 40 AT TIMES. GFS BUFR SOUNDINGS
SUPPORT AN ADVISORY...BUT ISSUES OVER THE PAST SEVERAL MONTHS OF
DRIER THAN EXPECTED SOUNDINGS MAY BE ADDING TO MIXING LAYER HEIGHT
AND THUS POTENTIAL FOR OVERESTIMATES OF MAX WIND GUST. THE NAM HAS
BEEN SLIGHTLY MORE SUBDUED...BUT STILL RATHER BRISK FOR THIS TIME OF
THE YEAR. DESPITE THE CHALLENGE OF ACCEPTING THE GFS SOUNDINGS
TODAY...H850 WINDS WILL REACH 40 TO 50KT BY MID TO LATE AFTERNOON
WHICH STILL SUGGESTS A DAY WITH GUSTS APPROACHING HEADLINE CRITERIA.
TEMPS WILL RESPOND ACCORDINGLY WITH HIGHS IN THE LOWER TO MID 80S BY
AFTERNOON...SO WARM AND BREEZY FOR MID SEPTEMBER. WITH ANOTHER WEAK
WAVE AND WARM AIR ADVECTION MOVING ACROSS THE AREA TODAY...WILL KEEP
SOME POP CHANCES GOING AS PREVIOUSLY MENTIONED. GFS/NAM AND HRRR ALL
SUPPORT AT LEAST A SLIGHT CHANCE INTO THE AFTERNOON HOURS TODAY.
CLOUDS WILL BE IN AND OUT OF THE AREA WITH WAVE PASSAGE AND WARM AIR
ADVECTION TODAY. WINDS WILL BEGIN TO SUBSIDE AFTER 23Z.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 357 AM CDT TUE SEP 15 2015
TONIGHT THROUGH THURSDAY MORNING...WINDY CONDITIONS WILL CONTINUE
OVER THE STATE AS RIDGING OVER THE EASTERN THIRD OF THE US AND A LOW
PRESSURE SYSTEM EJECTING OFF THE NORTHERN ROCKIES WORKS TO KEEP THE
SURFACE PRESSURE GRADIENT RATHER TIGHT.
SHORTWAVES WILL ALSO CONTINUE TO PROPAGATE THROUGH THE SW UPPER
LEVEL FLOW...SPARKING OFF OPPORTUNITIES FOR A FEW SHOWERS/STORMS AT
TIMES. SLIGHT CHANCE POPS ARE GENERALLY SECLUDED TO NW IA TONIGHT
AND THEN MORE BROADLY ACROSS CENTRAL IOWA WED NIGHT/THUR MORNING. A
ROBUST INVERSION WILL GENERALLY DO A GOOD JOB OF SQUASHING PRECIP
POTENTIAL...BUT CONSIDERING A ROUGHLY 50KT LLJ AND PROGGED UPGLIDE
OF 100+MB...A FEW SHOWERS ARE LIKELY TO SPARK OFF. WED NIGHT/THUR
WILL SEE SIMILAR SET UP WITH AN INVERSION...THOUGH IT WILL BE
WEAKER...A NEARLY 50KT LLJ AND UPGLIDE OF 100+MB. ALSO PRESENT WILL
BE A BETTER MOISTURE PROFILE AND RESULTING ELEVATED CAPE AROUND 700-
1000 J/KG. MODELS RESULT IN KIND WITH MORE WIDESPREAD OPPORTUNITIES
FOR SHOWERS/STORMS. WHILE A BIT OF THUNDER IS POSSIBLE/LIKELY WITH
STORMS WED NIGHT/THUR MORNING...UNSUPPORTIVE DEEP SHEAR LIMITS
POTENTIAL FOR ANYTHING SEVERE.
THURSDAY THROUGH FRIDAY...THE WESTERN TROUGH FINALLY MAKES ITS WAY
EASTWARD ACROSS THE ROCKIES AND INTO THE PLAINS. A SURFACE LOW WILL
DEVELOP AHEAD OF THE MAIN TROUGH AND TREKS ACROSS THE DAKOTAS AND
NORTHERN MN WED AND THUR. THE TRAILING SURFACE FRONT WILL BEGIN TO
MOVE INTO THE AREA THURSDAY AFTERNOON...SPARKING OFF SHOWERS/STORMS
ALONG THE WAY. MODELS THE LAST COUPLE OF RUNS HAVE HINTED AT
STALLING THE BOUNDARY ACROSS THE SOUTH AND NORTHERN MO...AND
CONTINUE WITH THAT SOLUTION. THEN FRIDAY THE MAIN UPPER LEVEL TROUGH
PUSHES THROUGH THE REGION AND PROVIDES ANOTHER OPPORTUNITY FOR
SHOWERS/STORMS. WITH TEMPS AND DEW PTS AT THEIR HIGHEST OF THE
WEEK...A DECENT AMOUNT INSTABILITY WILL BE AROUND THURSDAY...AROUND
1000-2000 J/KG. A GENERALLY LACKLUSTER SHEAR PROFILE WILL LIMIT
SEVERE POTENTIAL. STORY FRI IS SIMILAR...THOUGH FURTHER SOUTH
WHEREVER THE REMNANT/STALLED FRONT ENDS UP.
SATURDAY THROUGH TUESDAY...HIGH PRESSURE SETS IN BEHIND THE FRONT
AND TEMPERATURES FALL BACK INTO THE 70S...MAKING FOR A PLEASANT
WEEKEND AND START TO THE NEW WEEK.
&&
.AVIATION...15/12Z
ISSUED AT 650 AM CDT TUE SEP 15 2015
WINDS THE MAIN CONCERN TODAY. STRONG H850 JET EXPECTED OVER THE
AREA TODAY...WITH 40-50KTS ALOFT AND BUFR SOUNDINGS SUGGESTING
QUICK INCREASE IN MIXING BY 15-16Z RESULTING IN WIND GUSTS
25-33 KTS ACROSS THROUGH 23Z. MID LEVEL WARM AIR ADVECTION HAS
RESULTED IN A BKN110-BKN150 DECK WITH CIGS EXPECTED TO REMAIN VFR
THROUGH THE PERIOD. AS SHORT WAVE CROSSES THE STATE AFT 16Z...SCT
SHOWERS/ISO THUNDER POSSIBLE OVER WEST/NORTHWEST MAINLY. CONFIDENCE
ON COVERAGE IS LOW...SO HAVE ONLY INCLUDED VCSH AT KFOD AND KMCW
AT THIS TIME. WINDS REMAIN BRISK AFT 00Z THOUGH GUSTS WILL DIMINISH
AS BOUNDARY LAYER DECOUPLES. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...CURTIS
AVIATION...REV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
546 AM MDT TUE SEP 15 2015
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 410 AM MDT TUE SEP 15 2015
FORECAST PROBLEMS WILL BE CHANCES OF PRECIPITATION...CONTINUED FIRE
WEATHER ISSUES INTO WEDNESDAY...AND HIGH TEMPERATURES. SATELLITE IS
SHOWING AN AMPLIFIED AND RETROGRESSIVE FLOW FROM THE PACIFIC TO
ALONG THE WEST COAST OF NORTH AMERICA. WESTERN TROUGH HAS BEGUN TO
DEVELOP WHICH NOW LEAVES THE AREA IN SOUTHWEST FLOW ALOFT. A RATHER
STRONG SHORTWAVE OVER THE DESERT SOUTHWEST IS MOVING TOWARD THE AREA
WITH RATHER MOIST MID LEVELS AHEAD OF IT.
AT JET LEVEL...THE NAM...CANADIAN...GFS AND ECMWF WERE DOING THE
BEST. AT MID LEVELS...THE UKMET/CANADIAN WERE DOING A LITTLE BETTER
THAN THE GFS/ECMWF. MODELS WERE HAVING THEIR PROBLEMS AT THE
SURFACE. THE RAP AND NAM WERE DOING THE BEST. THE NAM/CANADIAN/SREF
WERE DOING A LITTLE BETTER THAN THE GFS ON THE LOW LEVEL THERMAL
FIELD.
TODAY/TONIGHT...REFER TO THE FIRE WEATHER SECTION BELOW FOR
DISCUSSION ON FIRE WEATHER.
STILL A TRICKY/COMPLICATED THUNDERSTORM FORECAST WITH A LOT OF
UNCERTAINTY. LEFT FRONT QUADRANT OF THE SOUTHERN JET AFFECTS THE
SOUTHERN THIRD OF THE AREA LATE THIS AFTERNOON INTO EARLY THIS
EVENING BEFORE MOVING OFF. PROBLEM TO OVERCOME IS APPARENT LACK OF
LOW LEVEL MOISTURE AND INSTABILITY. THE TREND IN THE MODELS FOR THE
LAST THREE DAYS HAS BEEN TO PULL THE SURFACE TROUGH AND HIGHER
DEWPOINTS FURTHER EAST. CONSEQUENTLY THE INSTABILITY AXIS AND WHERE
THUNDERSTORMS INITIATE ARE ALSO FURTHER WEST AS WELL.
AS STATED ABOVE A DECENT SLUG OF MID LEVEL MOISTURE IS APPROACHING
FROM THE SOUTHWEST. SO THERE APPEARS TO BE BETTER MOISTURE THROUGH A
GREATER THAN INDICATED THE LAST FEW DAYS. SATELLITE/PV ANALYSIS
SHOULD A RATHER STRONG SHORTWAVE TROUGH IS MOVING FROM THE
SOUTHWEST. HOWEVER ARE TENDING WEAKEN THIS SOME WHICH DOES NOT SEEM
RIGHT. ALSO AFTER 00Z MODELS CONTINUE TO SHOW A RATHER STRONG LOW
LEVEL JET OVER THE EASTERN THIRD TO HALF OF THE FORECAST AREA.
CONVECTIVE ALLOWING MODELS ARE SHOWING MORE ROBUST CONVECTION
THAN PREVIOUSLY SHOWN WITH THE POSSIBILITY OF 2 OR 3 AREAS/TIME
PERIODS OF INITIATION. SO EXPANDED POPS FURTHER WEST AND INCREASED
POPS TO LOW CHANCE IN THE FAR SOUTH THIS AFTERNOON AND EARLY EVENING
DUE TO THE JET AND OVER THE EASTERN FORECAST AREA DUE TO THE LOW
LEVEL JET AND STRONG SHORTWAVE MOVING THROUGH.
WILL KEEP THINGS HOT AGAIN TODAY ALTHOUGH THE DOWNSLOPE COMPONENT TO
THE WINDS MAY NOT LAST AS LONG AS PREVIOUSLY INDICATED. ALSO CLOUD
COVER MOVING IN FROM THE SOUTHWEST AND WITH THUNDERSTORM INITIATION
COULD HOLD BACK THE WARMING. AT THIS TIME IT LOOKS LIKE MID TO UPPER
90S FOR THE AREA.
WEDNESDAY/WEDNESDAY NIGHT...REFER TO THE FIRE WEATHER SECTION BELOW
FOR DISCUSSION ON FIRE WEATHER.
MODELS ROTATE LEFT FRONT QUADRANT OF THE JET ACROSS THE AREA THROUGH
THE DAY. THE MODELS DO NOT MOVE THIS VERY FAR OFF WITH SOME KIND OF
JET LIFT THROUGH THE NIGHT ESPECIALLY OVER THE NORTHERN AND WESTERN
PORTIONS. HOWEVER THE SOUNDINGS SHOW AN EXTREMELY DEEP DRY AIR MASS.
SOME OF THE NWP IS SHOWING LOW POPS BUT THAT SEEMS OVERDONE.
CONVECTIVE ALLOWING MODELS ARE DRY. SO THIS LIFT LOOKS TO JUST
PRODUCE CLOUDS AND HAVE THE FORECAST DRY THROUGH THE PERIOD.
MODELS ARE SAYING IT SHOULD BE SLIGHTLY COOLER. MODELS HAVE HAD A
TENDENCY TO BE TOO COOL. HOWEVER THE WIND FIELD IS LIGHTER AND NOT
AS HELPFUL IN GETTING THE TEMPERATURES WARMER. SO TEMPERATURES AT
THIS WILL BE NEAR OR SLIGHTLY COOLER THAN WHAT WAS IN THERE FOR
TODAY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OR OVER THE
NORTHERN AND WESTERN SECTIONS THROUGH THE PERIOD. AGAIN THE
SOUNDINGS ARE INITIALLY SHOWING A DEEP DRY LAYER BUT NOT AS MUCH AS
THE PREVIOUS DAY. AT THIS TIME DOES LOOK LIKE THE STRONGER LIFT DOES
NOT ARRIVE UNTIL THE NIGHT PERIOD AND ESPECIALLY IN THE LAST HALF OF
THE NIGHT. AGAIN AM NOT CONFIDENT ABOUT THIS DUE TO A LACK OF
SIGNIFICANT MOISTURE BUT THE LIFT IS PRETTY STRONG. AT THIS IT LOOKS
LIKE THE NORTHEAST HALF WILL HAVE THE BEST CHANCE FOR PRECIPITATION.
IT DOES LOOK COOLER BUT THE MODELS DISAGREE ON HOW MUCH COOLER. WILL
DEFINITELY HAVE THE MOST UNFAVORABLE WIND FIELD OUT OF THE LAST 3
DAYS TO HELP THE WARMING. GOING BY RECENT TRENDS/BIASES...I DID MAKE
THE MAXES COOLER BUT TRENDED TOWARD THE WARMER GUIDANCE.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 202 AM MDT TUE SEP 15 2015
THE LONG TERM STARTS OFF WITH AN H5 RIDGE THAT WILL SETTLE SOUTHWARD
INTO SOUTHWESTERN TEXAS. THE FLOW PATTERN ALOFT WILL SHIFT FROM
SOUTHWEST THEN TO WEST AND EVENTUALLY TO WEST NORTHWEST OVER THE
EXTENDED PERIOD. AS THIS HAPPENS... SEVERAL H7 TROUGHS WILL MOVE OUT
OF THE CENTRAL ROCKIES AND THEN MOVE EASTWARD ACROSS THE CWA.
CONFIDENCE IN THE GUIDANCE IS RELATIVELY LOW AT THIS POINT WITH THE
GFS AND ECMWF BEING IN STRONG DISAGREEMENT WITH REGARDS TO THE
AMOUNT OF MOISTURE THAT WILL BE AVAILABLE WHEN THIS HAPPENS.
CURRENTLY THE ECMWF IS THE WETTER OF THE TWO HOWEVER THIS IS
OPPOSITE OF THE SCENARIO IN EARLIER MODEL RUNS. I WENT WITH AROUND
20 PERCENT POPS ON SATURDAY IN THE SOUTHERN PORTIONS OF THE CWA AS
ONE OF THESE H7 TROUGHS MOVE ACROSS THE REGION AND THEN WITH 30
PERCENT POPS ON SUNDAY AFTERNOON AS A STRONGER H5 TROUGH MOVES
ACROSS THE AREA. IF THE ECMWF SOLUTION PROVES TRUE THEN POP CHANCES
WOULD BE IN THE 40 TO 50 PERCENT RANGE BUT WE WILL NEED TO MONITOR
THE FUTURE MODEL RUNS TO SEE IF THERE IS ANY CONSISTENCY. THE GFS
SHOWS A MOSTLY DRY FORECAST FOR THIS SAME TIME FRAME.
TEMPERATURES DURING THE EXTENDED PERIOD WILL BEGIN NEAR NORMAL WITH
HIGHS IN THE 70S AND LOWS IN THE 40S TO LOW 50S ON FRIDAY AND
SATURDAY... THEN INCREASING ON SUNDAY AND MONDAY WITH HIGHS IN THE
80S AND LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 542 AM MDT TUE SEP 15 2015
AT THIS TIME VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
SOUTHERLY WINDS WILL INCREASE INTO EARLY AFTERNOON...FIRST AT KGLD
THEN KMCK. SUSTAINED WINDS WILL BE 17 TO 20 KNOTS WITH GUSTS OF 25
TO 30 KNOTS. THE WINDS WILL DECREASE A LITTLE NEAR OR SHORTLY
AFTER SUNSET BUT WILL STILL BE GUSTY UNTIL AFTER 06Z.
ISOLATED THUNDERSTORMS ARE EXPECTED NEAR BOTH TAF SITES. CERTAINTY
IS A LITTLE HIGHER NOW THAN EARLIER TONIGHT. SINCE DO NOT EXPECTED
THUNDERSTORMS TO DEVELOP AFTER 21Z...CHOSE TO ONLY PUT IN VCTS AT
BOTH SITES FROM LATE AFTERNOON INTO THE LATE EVENING HOURS.
&&
.FIRE WEATHER...
ISSUED AT 410 AM MDT TUE SEP 15 2015
FOR TODAY...IN SHORT DESPITE A LITTLE MORE UNCERTAINTY WILL BE
KEEPING THE CURRENT RED FLAG WARNING. AM A LITTLE CONCERNED WITH THE
SLIGHT WESTWARD SHIFT OF HIGHER DEWPOINTS. SAYING THAT HOWEVER IF
MORE MIXING OCCURS THAN I THINK DEWPOINTS COULD BE SHARPLY LOWER
THAN WHAT I HAVE THEM. THE WINDS WILL DEFINITELY REACH THE NEEDED
CRITERIA. ALSO WILL BE HAVING HIGH BASED THUNDERSTORMS WITH GUSTY
AND ERRATIC WINDS AND NOT A LOT OF RAINFALL.
FOR WEDNESDAY...AT THIS TIME A MARGINAL FIRE WEATHER DAY IS
EXPECTED. WINDS WILL BE LIGHT AND VARIABLE UNTIL MID AFTERNOON DUE
TO ONE SURFACE TROUGH MOVING OFF TO THE EAST AND THE NEXT ONE
FORMING TO THE WEST. MODELS DO HANDLE THIS SCENARIO WELL AND USUALLY
OVERPREDICT WIND SPEEDS. MODELS DO SHOW WINDS INCREASING TO 10 TO 20
MPH WITH GUSTS TO NEAR 25 MPH AROUND MID AFTERNOON. RELATIVE
HUMIDITIES LOOK TO BE A LITTLE HIGHER AND CLOSER TO 20 PERCENT
RATHER THAN 15 PERCENT. THINKING IS THAT WE WILL NOT BE ABLE TO MEET
THE 3 HOUR CRITERIA. WILL BRIEF THE DAY SHIFT ON THIS AND MENTION
THE POSSIBILITY IN THE HWO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 6 PM MDT /7
PM CDT/ THIS EVENING FOR KSZ001-013-027-041.
CO...RED FLAG WARNING FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR
COZ252>254.
NE...RED FLAG WARNING FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR
NEZ079.
&&
$$
SHORT TERM...BULLER
LONG TERM...TL
AVIATION...BULLER
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
412 AM MDT TUE SEP 15 2015
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 410 AM MDT TUE SEP 15 2015
FORECAST PROBLEMS WILL BE CHANCES OF PRECIPITATION...CONTINUED FIRE
WEATHER ISSUES INTO WEDNESDAY...AND HIGH TEMPERATURES. SATELLITE IS
SHOWING AN AMPLIFIED AND RETROGRESSIVE FLOW FROM THE PACIFIC TO
ALONG THE WEST COAST OF NORTH AMERICA. WESTERN TROUGH HAS BEGUN TO
DEVELOP WHICH NOW LEAVES THE AREA IN SOUTHWEST FLOW ALOFT. A RATHER
STRONG SHORTWAVE OVER THE DESERT SOUTHWEST IS MOVING TOWARD THE AREA
WITH RATHER MOIST MID LEVELS AHEAD OF IT.
AT JET LEVEL...THE NAM...CANADIAN...GFS AND ECMWF WERE DOING THE
BEST. AT MID LEVELS...THE UKMET/CANADIAN WERE DOING A LITTLE BETTER
THAN THE GFS/ECMWF. MODELS WERE HAVING THEIR PROBLEMS AT THE
SURFACE. THE RAP AND NAM WERE DOING THE BEST. THE NAM/CANADIAN/SREF
WERE DOING A LITTLE BETTER THAN THE GFS ON THE LOW LEVEL THERMAL
FIELD.
TODAY/TONIGHT...REFER TO THE FIRE WEATHER SECTION BELOW FOR
DISCUSSION ON FIRE WEATHER.
STILL A TRICKY/COMPLICATED THUNDERSTORM FORECAST WITH A LOT OF
UNCERTAINTY. LEFT FRONT QUADRANT OF THE SOUTHERN JET AFFECTS THE
SOUTHERN THIRD OF THE AREA LATE THIS AFTERNOON INTO EARLY THIS
EVENING BEFORE MOVING OFF. PROBLEM TO OVERCOME IS APPARENT LACK OF
LOW LEVEL MOISTURE AND INSTABILITY. THE TREND IN THE MODELS FOR THE
LAST THREE DAYS HAS BEEN TO PULL THE SURFACE TROUGH AND HIGHER
DEWPOINTS FURTHER EAST. CONSEQUENTLY THE INSTABILITY AXIS AND WHERE
THUNDERSTORMS INITIATE ARE ALSO FURTHER WEST AS WELL.
AS STATED ABOVE A DECENT SLUG OF MID LEVEL MOISTURE IS APPROACHING
FROM THE SOUTHWEST. SO THERE APPEARS TO BE BETTER MOISTURE THROUGH A
GREATER THAN INDICATED THE LAST FEW DAYS. SATELLITE/PV ANALYSIS
SHOULD A RATHER STRONG SHORTWAVE TROUGH IS MOVING FROM THE
SOUTHWEST. HOWEVER ARE TENDING WEAKEN THIS SOME WHICH DOES NOT SEEM
RIGHT. ALSO AFTER 00Z MODELS CONTINUE TO SHOW A RATHER STRONG LOW
LEVEL JET OVER THE EASTERN THIRD TO HALF OF THE FORECAST AREA.
CONVECTIVE ALLOWING MODELS ARE SHOWING MORE ROBUST CONVECTION
THAN PREVIOUSLY SHOWN WITH THE POSSIBILITY OF 2 OR 3 AREAS/TIME
PERIODS OF INITIATION. SO EXPANDED POPS FURTHER WEST AND INCREASED
POPS TO LOW CHANCE IN THE FAR SOUTH THIS AFTERNOON AND EARLY EVENING
DUE TO THE JET AND OVER THE EASTERN FORECAST AREA DUE TO THE LOW
LEVEL JET AND STRONG SHORTWAVE MOVING THROUGH.
WILL KEEP THINGS HOT AGAIN TODAY ALTHOUGH THE DOWNSLOPE COMPONENT TO
THE WINDS MAY NOT LAST AS LONG AS PREVIOUSLY INDICATED. ALSO CLOUD
COVER MOVING IN FROM THE SOUTHWEST AND WITH THUNDERSTORM INITIATION
COULD HOLD BACK THE WARMING. AT THIS TIME IT LOOKS LIKE MID TO UPPER
90S FOR THE AREA.
WEDNESDAY/WEDNESDAY NIGHT...REFER TO THE FIRE WEATHER SECTION BELOW
FOR DISCUSSION ON FIRE WEATHER.
MODELS ROTATE LEFT FRONT QUADRANT OF THE JET ACROSS THE AREA THROUGH
THE DAY. THE MODELS DO NOT MOVE THIS VERY FAR OFF WITH SOME KIND OF
JET LIFT THROUGH THE NIGHT ESPECIALLY OVER THE NORTHERN AND WESTERN
PORTIONS. HOWEVER THE SOUNDINGS SHOW AN EXTREMELY DEEP DRY AIR MASS.
SOME OF THE NWP IS SHOWING LOW POPS BUT THAT SEEMS OVERDONE.
CONVECTIVE ALLOWING MODELS ARE DRY. SO THIS LIFT LOOKS TO JUST
PRODUCE CLOUDS AND HAVE THE FORECAST DRY THROUGH THE PERIOD.
MODELS ARE SAYING IT SHOULD BE SLIGHTLY COOLER. MODELS HAVE HAD A
TENDENCY TO BE TOO COOL. HOWEVER THE WIND FIELD IS LIGHTER AND NOT
AS HELPFUL IN GETTING THE TEMPERATURES WARMER. SO TEMPERATURES AT
THIS WILL BE NEAR OR SLIGHTLY COOLER THAN WHAT WAS IN THERE FOR
TODAY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OR OVER THE
NORTHERN AND WESTERN SECTIONS THROUGH THE PERIOD. AGAIN THE
SOUNDINGS ARE INITIALLY SHOWING A DEEP DRY LAYER BUT NOT AS MUCH AS
THE PREVIOUS DAY. AT THIS TIME DOES LOOK LIKE THE STRONGER LIFT DOES
NOT ARRIVE UNTIL THE NIGHT PERIOD AND ESPECIALLY IN THE LAST HALF OF
THE NIGHT. AGAIN AM NOT CONFIDENT ABOUT THIS DUE TO A LACK OF
SIGNIFICANT MOISTURE BUT THE LIFT IS PRETTY STRONG. AT THIS IT LOOKS
LIKE THE NORTHEAST HALF WILL HAVE THE BEST CHANCE FOR PRECIPITATION.
IT DOES LOOK COOLER BUT THE MODELS DISAGREE ON HOW MUCH COOLER. WILL
DEFINITELY HAVE THE MOST UNFAVORABLE WIND FIELD OUT OF THE LAST 3
DAYS TO HELP THE WARMING. GOING BY RECENT TRENDS/BIASES...I DID MAKE
THE MAXES COOLER BUT TRENDED TOWARD THE WARMER GUIDANCE.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 202 AM MDT TUE SEP 15 2015
THE LONG TERM STARTS OFF WITH AN H5 RIDGE THAT WILL SETTLE SOUTHWARD
INTO SOUTHWESTERN TEXAS. THE FLOW PATTERN ALOFT WILL SHIFT FROM
SOUTHWEST THEN TO WEST AND EVENTUALLY TO WEST NORTHWEST OVER THE
EXTENDED PERIOD. AS THIS HAPPENS... SEVERAL H7 TROUGHS WILL MOVE OUT
OF THE CENTRAL ROCKIES AND THEN MOVE EASTWARD ACROSS THE CWA.
CONFIDENCE IN THE GUIDANCE IS RELATIVELY LOW AT THIS POINT WITH THE
GFS AND ECMWF BEING IN STRONG DISAGREEMENT WITH REGARDS TO THE
AMOUNT OF MOISTURE THAT WILL BE AVAILABLE WHEN THIS HAPPENS.
CURRENTLY THE ECMWF IS THE WETTER OF THE TWO HOWEVER THIS IS
OPPOSITE OF THE SCENARIO IN EARLIER MODEL RUNS. I WENT WITH AROUND
20 PERCENT POPS ON SATURDAY IN THE SOUTHERN PORTIONS OF THE CWA AS
ONE OF THESE H7 TROUGHS MOVE ACROSS THE REGION AND THEN WITH 30
PERCENT POPS ON SUNDAY AFTERNOON AS A STRONGER H5 TROUGH MOVES
ACROSS THE AREA. IF THE ECMWF SOLUTION PROVES TRUE THEN POP CHANCES
WOULD BE IN THE 40 TO 50 PERCENT RANGE BUT WE WILL NEED TO MONITOR
THE FUTURE MODEL RUNS TO SEE IF THERE IS ANY CONSISTENCY. THE GFS
SHOWS A MOSTLY DRY FORECAST FOR THIS SAME TIME FRAME.
TEMPERATURES DURING THE EXTENDED PERIOD WILL BEGIN NEAR NORMAL WITH
HIGHS IN THE 70S AND LOWS IN THE 40S TO LOW 50S ON FRIDAY AND
SATURDAY... THEN INCREASING ON SUNDAY AND MONDAY WITH HIGHS IN THE
80S AND LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1000 PM MDT MON SEP 14 2015
FOR KGLD AND KMCK...VFR THROUGH THE PERIOD. WILL HAVE TO WATCH FOR
A FEW THUNDERSTORMS AT BOTH TERMINALS IN THE 22Z-03Z TIMEFRAME.
RIGHT NOW WONT INCLUDE ANY MENTION GIVEN ISOLATED NATURE AND
CURRENT MODEL SOLUTIONS WHICH KEEP BETTER CHANCES SOUTH OF BOTH
TERMINALS.
KGLD...SOUTHEAST WINDS AROUND 10KTS AT TAF ISSUANCE EXPECTED TO
VEER TO THE SOUTHWEST AT SIMILAR SPEEDS BY 09Z CONTINUING THROUGH
14Z. AROUND 15Z WINDS START TO INCREASE WITH 12KTS BUT BY 18Z GUST
NEAR 25KTS FROM THE SOUTHWEST AS SFC LOW DEEPENS OVER NORTHEAST
COLORADO INCREASING LOW LEVEL PRESSURE GRADIENT. FOR THE MID TO
LATE AFTERNOON HOURS GUSTS NEAR 30KTS EXPECTED. FOR THE EVENING
HOURS WINDS MAY BACK A BIT TOWARD THE SOUTH OTHERWISE STILL
EXPECTING GUSTS OVER 25KTS.
KMCK...A LIGHT SOUTHEAST WIND AT TAF ISSUANCE EXPECTED THROUGH 13Z
BEFORE VEERING TO THE SOUTHWEST NEAR 10KTS BY 14Z. THIS CONTINUES
THROUGH 18Z BEFORE WIND GUSTS AROUND 20KTS START AROUND
19Z...INCREASING TO NEAR 30KTS AFTER 23Z. SIMILAR TO KGLD WINDS
BACK A BIT DURING THE EVENING HOURS WITH GUSTS OF 20-30KTS
CONTINUING.
&&
.FIRE WEATHER...
ISSUED AT 410 AM MDT TUE SEP 15 2015
FOR TODAY...IN SHORT DESPITE A LITTLE MORE UNCERTAINTY WILL BE
KEEPING THE CURRENT RED FLAG WARNING. AM A LITTLE CONCERNED WITH THE
SLIGHT WESTWARD SHIFT OF HIGHER DEWPOINTS. SAYING THAT HOWEVER IF
MORE MIXING OCCURS THAN I THINK DEWPOINTS COULD BE SHARPLY LOWER
THAN WHAT I HAVE THEM. THE WINDS WILL DEFINITELY REACH THE NEEDED
CRITERIA. ALSO WILL BE HAVING HIGH BASED THUNDERSTORMS WITH GUSTY
AND ERRATIC WINDS AND NOT A LOT OF RAINFALL.
FOR WEDNESDAY...AT THIS TIME A MARGINAL FIRE WEATHER DAY IS
EXPECTED. WINDS WILL BE LIGHT AND VARIABLE UNTIL MID AFTERNOON DUE
TO ONE SURFACE TROUGH MOVING OFF TO THE EAST AND THE NEXT ONE
FORMING TO THE WEST. MODELS DO HANDLE THIS SCENARIO WELL AND USUALLY
OVERPREDICT WIND SPEEDS. MODELS DO SHOW WINDS INCREASING TO 10 TO 20
MPH WITH GUSTS TO NEAR 25 MPH AROUND MID AFTERNOON. RELATIVE
HUMIDITIES LOOK TO BE A LITTLE HIGHER AND CLOSER TO 20 PERCENT
RATHER THAN 15 PERCENT. THINKING IS THAT WE WILL NOT BE ABLE TO MEET
THE 3 HOUR CRITERIA. WILL BRIEF THE DAY SHIFT ON THIS AND MENTION
THE POSSIBILITY IN THE HWO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 6 PM MDT /7
PM CDT/ THIS EVENING FOR KSZ001-013-027-041.
CO...RED FLAG WARNING FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR
COZ252>254.
NE...RED FLAG WARNING FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR
NEZ079.
&&
$$
SHORT TERM...BULLER
LONG TERM...TL
AVIATION...99
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
725 AM EDT TUE SEP 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 531 AM EDT TUE SEP 15 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF DEVELOPING OVER THE
WRN CONUS WHICH IS FORCING A BUILDING DOWNSTREAM RIDGE OVER THE ERN
CONUS. RESULTING SW FLOW INTO THE UPPER GREAT LAKES IS GENERALLY
QUIET. HOWEVER...A VERY PRONOUNCED ELEVATED MIXED LAYER/VERY STEEP
MID LEVEL LAPSE RATES OF 8-9C/KM EVIDENT ON 00Z SOUNDINGS ACROSS THE
CNTRL/NRN PLAINS AND UPPER MISSISSIPPI VALLEY IS SUPPORTING A FEW
SHRA/TSRA ACROSS PORTIONS OF CNTRL/SRN WI EARLY THIS MORNING WHERE A
POOL OF HIGHER 700MB THETA-E IS LOCATED PER RAP ANALYSIS. CLOSER TO
HOME...CLR SKIES HAVE BEEN THE RULE OVERNIGHT. HOWEVER...SRLY FLOW
UP LAKE MICHIGAN HAS BEEN ADVECTING HIGHER DWPTS INTO THE COOLER
INTERIOR...RESULTING IN SOME PATCHY FOG/STRATUS.
ANOTHER WARM LATE SUMMER DAY IS ON THE WAY TODAY. ALTHOUGH 850MB
TEMPS WILL BE ON THE ORDER OF 18-20C TODAY...PROBABLY WON`T BE ABLE
TO MIX TO 850MB AND REALIZE THAT WARMTH GIVEN THE STRONG INVERSION
AND LOWER SUN ANGLE THIS TIME OF YEAR. EXPECT MAX TEMPS IN THE UPPER
70S TO MID 80S...WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
HIGHS ALONG THE LAKE MICHIGAN SHORE E OF KESC WILL BE AROUND 70F.
TIGHTENING GRADIENT BTWN NORTHERN PLAINS LOW PRES AND HIGH PRES TO
THE ESE WILL SUPPORT BREEZY SSW WINDS THIS AFTN AS NOTED ON FCST
SOUNDINGS. MIXED LAYER SUPPORTS WIND GUSTS INTO THE 25-30MPH RANGE
MOST AREAS WITH POTENTIAL TO GUST TO AROUND 35MPH WHERE DOWNSLOPE
WARMING AIDS MIXING DEPTH. NOT OUT OF THE QUESTION THAT A FEW
SPRINKLES OR ISOLD -SHRA COULD OCCUR THIS MORNING OVER THE SCNTRL/E
AS POOL OF HIGHER 700MB THETA-E LIFTS NE. WITH VERY DRY AIR BLO THE
10KFT+ HIGH CLOUD BASES...WILL LEAVE FCST DRY FOR NOW AND MONITOR
UPSTREAM PCPN EVOLUTION.
LOW-LEVEL JET CONTINUES TO RAMP UP TONIGHT WITH WINDS AT THE 2KFT
LEVEL UP TO 50-60KT W AND 40-45KT E. COULD BE A SET UP FOR WINDY
CONDITIONS IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR SUCH AS
MARQUETTE. OTHERWISE...WITH STRENGTHENING NOCTURNAL INVERSION...
GUSTS WILL ONLY BE 10-20MPH. THE WINDS WILL KEEP TEMPS UP TONIGHT.
EXPECT MINS IN THE UPPER 50S TO UPPER 60S...WARMEST IN THE DOWNSLOPE
AREAS NEAR LAKE SUPERIOR. WITH PRONOUNCED ELEVATED MIXED LAYER/VERY
STEEP MID LEVEL LAPSE RATES OVER THE AREA...CAN`T COMPLETELY RULE
OUT AN ISOLD SHRA OR TSTM AS LOW-LEVEL JET INCREASES WITH ANOTHER
PUSH OF 700MB THETA-E. HOWEVER...GIVEN THE OVERALL DRY AIR MASS...
POTENTIAL APPEARS TOO LOW TO INCLUDE A MENTION OF PCPN IN FCST. IN
ADDITION...THERE ARE FEWER MODEL RUNS INDICATING PCPN TONIGHT
COMPARED TO PREVIOUS RUNS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 338 AM EDT TUE SEP 15 2015
THE CWA WILL CONTINUE TO BE UNDER SW FLOW ALOFT BETWEEN RIDGING TO
THE E AND TROUGHING TO THE W. SEVERAL SHORTWAVES WILL PASS NEARBY
FROM MID TO LATE WEEK.
FOR WED...SLIGHT CHANCE POPS OVER MAINLY THE WRN CWA SEEMS
REASONABLE GIVEN THAT A SHORTWAVE WILL STAY NW OF THE AREA
(SASKATCHEWAN AND FAR NW ONTARIO) AND DRY LOW-MID LEVELS WILL
PREVENT MOST AREAS FROM SEEING PRECIP. EXPECT HIGH TEMPS FROM THE
MID 70S NEAR LAKE MICHIGAN TO THE MID 80S NEAR LAKE SUPERIOR AS SSW
WINDS GUSTING TO 20-25 KTS DOWNSLOPE TOWARD THE BIG LAKE.
PRECIP CHANCES BEGIN INCREASING WED NIGHT AS A STRONGER SHORTWAVE
AND SFC LOW MOVE CLOSER TO THE CWA...ACROSS NRN MN AND INTO ONTARIO.
STILL ONLY HAVE CHANCE POPS WED NIGHT INTO THU AFTERNOON...BUT
SHOWERS AND THUNDERSTORMS BECOME LIKELY THU EVENING AND THU NIGHT AS
THE SFC TROUGH/COLD FRONT MOVE W-E ACROSS THE AREA. THINK THERE
COULD BE SOME STRONG TO SEVERE STORMS THU EVENING AS MUCAPE VALUES
LOOK TO BE 1000-2000 J/KG AND DEEP LAYER SHEAR IS AROUND 30KTS. CAPE
AND EFFECTIVE SHEAR DIMINISH LATER IN THE EVENING AND OVERNIGHT THU
NIGHT AS STORMS BECOME ELEVATED...SO SEVERE THREAT WILL ALSO
DIMINISH. PLENTY OF MOISTURE OVERHEAD WILL ALLOW FOR BRIEF HEAVY
RAINFALL. THU TEMPS LOOK TO BE A LITTLE COOLER THAN WED DUE TO
INCREASED CLOUD COVER...BUT WILL STILL SEE HIGHS ABOVE NORMAL IN THE
70S TO AROUND 80...WARMEST NEAR LAKE SUPERIOR.
LOTS OF UNCERTAINTY FOR FRI INTO SAT AS MODELS VARY ON HANDLING A
SHORTWAVE MOVING UP THE FRONT AND INTO THE GREAT LAKES REGION.
TIMING...TRACK AND STRENGTH OF THE SHORTWAVE WILL GREATLY IMPACT
WEATHER OVER THE CWA. FOR NOW...MODELS ARE IN SOME GENERAL AGREEMENT
THAT MAINLY THE SERN 1/2 TO 2/3 OF THE CWA WILL BE EFFECTED BY
PRECIP...BUT THEY DO DIFFER ON TIMING AND STRENGTH. WILL JUST USE A
CONSENSUS OF GUIDANCE AT THIS TIME. IT WILL BE QUITE A BIT COOLER
BEHIND THE FRONT...EXACTLY HOW MUCH DEPENDS ON PRECIP/CLOUD
COVER...BUT HIGHS IN THE 60S TO LOW 70S SEEMS REASONABLE.
SFC HIGH PRESSURE THEN LOOKS TO MOVE THROUGH OVER THE WEEKEND...WITH
SW FLOW ON THE BACK SIDE EARLY NEXT WEEK. NO PRECIP IS EXPECTED FROM
AT LEAST LATE SAT ON...AND TEMPS WILL GRADUALLY WARM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 724 AM EDT TUE SEP 15 2015
WITH A DRY AIR MASS REMAINING OVER THE AREA...VFR CONDITIONS WILL
PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD. WITH DAYTIME
HEATING...SOUTHERLY WINDS WILL BECOME GUSTY LATE MORNING/EARLY
AFTN...ESPECIALLY AT KIWD/KSAW. THE GRADIENT WILL BE STRONG ENOUGH
TO SUPPORT GUSTY WINDS THROUGH TONIGHT AT KIWD...AND PERHAPS KSAW.
WHERE WINDS LOOSE GUSTINESS THIS EVENING (KCMX AND PROBABLY
KSAW)...LLWS WILL DEVELOP AS LOW-LEVEL JET RAMPS UP OVER THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 531 AM EDT TUE SEP 15 2015
WINDY CONDITIONS ARE SHAPING UP FOR LAKE SUPERIOR THRU THU AS LAKE
SUPERIOR WILL BE SITUATED BTWN A LOW PRES TROF TO THE NW AND HIGH
PRES TO THE ESE. SOUTHERLY WINDS WILL SLOWLY RAMP UP TODAY AND WILL
REACH GENERALLY 15-25KT W HALF TO 20-30KT E HALF TONIGHT. NOT OUT OF
THE QUESTION THAT THE HIGHEST OBS PLATFORMS WILL SEE GALE FORCE
GUSTS. WINDS WILL DIMINISH SOME WED/THU...MORE SO OVER THE W HALF OF
THE LAKE. A COLD FRONT WILL PASS THU NIGHT/FRI MORNING WITH
GENERALLY 10-20KT WINDS TO FOLLOW INTO THE WEEKEND.
&&
.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 KANSAS CITY/PLEASANT HILL MO
555 AM CDT TUE SEP 15 2015
.DISCUSSION...
Issued at 303 AM CDT TUE SEP 15 2015
Over the next several hours, the development of a few isolated
showers and perhaps a stray thunderstorm continue to looks possible
where accas continues to develop and thicken across eastern KS. A
strong LLJ based around 1-1.5 kft and decent isentropic lift in the
310-315K layer will continue to support initiation through at least
sunrise if not a few hours after, and hi-res model guidance shows a
signal for precipitation by 11-12z with relatively good temporal and
spatial continuity. Any showers/storms that develop will drift east
before dissipating as the nocturnal LLJ diminishes diurnally later
in the morning, allowing skies to clear and temperatures to warm
into the mid to possibly upper 80s this afternoon. As was the case
yesterday, any mixing to a higher height than indicated in models
could bring highs several degrees warmer than forecast, but have
settled with a mixing height of around 925 hPa and somewhat
discounted the more extreme RAP solution which brings surface
temperatures near 90 degrees and surface dewpoints down to the upper
40s. Winds may be just a touch lighter this afternoon than
yesterday, but still with sustained speeds in the upper teens and
gusts to 25-30 mph especially during the late morning and early
afternoon.
The LLJ should focus more to the north and northeast tonight into
Wednesday morning, allowing any possible nocturnal convection to
develop and remain out of the forecast area. As a result, cloud
cover is not expected to hinder temperature rises, and highs could
reach the upper 80s CWA-wide Wednesday afternoon. Wednesday night
into early Thursday morning will be similar, but there is still a
decent signal for cold-pool driven storms sneaking into the
northeastern quadrant of the forecast area around sunrise, and thus
have continued lower-end PoPs for areas along/north of Hwy 36 and
east of STJ from after midnight through the late morning hours
Thursday.
On Thursday, a final lobe of surface low pressure will eject off the
lee-side of the Rockies and into the Dakotas, forcing its associated
cold front across the Plains and into the Great Lakes area Thursday
through Friday. The high temperature forecast Thursday will be
somewhat complicated as convergence ahead of the approaching cold
front enhances southerly surface flow and boundary layer mixing once
again, but while destructive warm-sector convection becomes probable
during the afternoon. Convective initiation should be shallow and
capped Thursday afternoon, then precipitation will become likely by
evening and especially the overnight hours into early Friday morning
along the boundary. The slow-moving nature of the front and PWAT
values on the order of 2 inches (over 150% of normal) may indicate
the potential for flash flooding as rounds of storms develop near
and ahead of the front, and while a few strong to marginally severe
storms are nearly always possible along a robust autumn cold front,
the main concern will likely be the heavy rains and flooding
potential.
After the front pushes out of the region on Friday evening, cooler
temperatures and gradually decreasing low-level moisture will make
for another autumn-like weekend across the region. While upper
heights do not fall quite as dramatically as with last weekend`s
system in the wake of the coming system, highs will likely top out
in the lower to mid 70s Saturday and a touch warmer in the mid to
upper 70s Sunday, before conditions once again moderate to near
normal early next week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 555 AM CDT TUE SEP 15 2015
A few isolated showers and storms will continue to shift east and
dissipate this morning, and should not impact terminals beyond 13z to
14z. Afterward, skies will gradually clear and southerly winds will
increase, gusting to 25 to 28 kts from mid-morning through at least
mid-afternoon. Gusts may begin to drop off during the mid- to late-
afternoon, but speeds will remain sustained above 12 kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
850 AM PDT TUE SEP 15 2015
.SYNOPSIS...A TROUGH OF LOW PRESSURE COMBINED WITH SEVERAL WAVES OF
ENERGY WITHIN IT WILL RESULT IN SHOWERS AND THUNDERSTORMS AROUND AS
WELL AS GUSTY WINDS ACROSS THE AREA TODAY AND TO A LESSER EXTENT ON
WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO MOHAVE,
LINCOLN AND CENTRAL NYE COUNTIES ON WEDNESDAY. OTHERWISE EXPECT DRY
CONDITIONS FROM THURSDAY THROUGH NEXT MONDAY. TEMPERATURES WILL
REMAIN BELOW NORMAL THROUGH THURSDAY THEN WARM BACK ABOVE NORMAL BY
THE WEEKEND.
&&
.UPDATE...PLUME OF RICH MOISTURE MOVING INTO SOUTHERN CALIFORNIA
OVERNIGHT HAS BROUGHT SUBSTANCIAL RAINFALL TO PARTS OF THE LA BASIN.
THIS PLUME IS EXPECTED TO DRIFT NORTHEAST TODAY ACROSS THE
INTERSTATE 15 CORRIDOR. LIGHT RAIN HAS ALREADY BEEN NOTED IN BARSTOW
AND BICYCLE LAKE WITH WIDESPREAD LIGHT RAIN INDICATED ON RADAR
ACROSS THE NORTHERN HALF OF SAN BERNARDINO COUNTY.
ANTICIPATE THIS RAINFALL WILL CONTINUE TO FILL IN THROUGH THE LATE
MORNING HOURS AND BEGIN TO INCREASE ACROSS PARTS OF CLARK COUNTY IN
THE NEXT FEW HOURS. I HAVE INCREASED POPS CONSIDERABLY ACROSS THE I-
15 CORRIDOR WHERE MOST WIDESPREAD PRECIPITATION IS LIKELY.
INSTABILITY WILL BE MORE LIMITED TODAY SO PRECIPITATION WILL
GENERALLY FALL IN THE FORM OF LIGHT SHOWERS AS OPPOSED TO
THUNDERSTORMS...THOUGH A FEW ISOLATED STORMS ARE STILL EXPECTED IN
THE AFTERNOON. RAINFALL AMOUNTS IN GENERAL WILL BE LESS THAN A TENTH
OF AN INCH.
A TENDENCY FOR DRYING CONDITIONS IS EXPECTED ACROSS MOHAVE COUNTY
THIS MORNING BEFORE ISOLATED THUNDERSTORMS BECOME POSSIBLE IN THE
AFTERNOON.
-OUTLER-
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT.
SHOWERS AND A FEW THUNDERSTORMS ARE STILL GOING ACROSS NORTHERN
MOHAVE AND FAR NORTHEAST CLARK COUNTIES EARLY THIS MORNING AS A WEAK
MID-LEVEL DISTURBANCE LIFTS NORTHEAST ACROSS THIS AREA. OUR
ATTENTION NOW TURNS TOWARD THE COAST OF SOCAL AS WELL AS THE SAN
JOAQUIN VALLEY AND SOUTHERN SIERRA WHERE SHOWERS WERE ADVANCING ON
EAST. THIS ACTIVITY WILL HEAD INTO INYO AND SAN BERNARDINO COUNTIES
THIS MORNING AS ANOTHER WAVE OF ENERGY ROTATES THROUGH THE BASE OF
THE TROUGH AIDED BY LIFT FROM A SPLIT JET STREAM OVER THE SOUTHERN
HALF OF CALIFORNIA. THE HRRR MODEL FORECASTS THE SOCAL SHOWERS TO
MAKE HEADWAY TOWARD THE CALIFORNIA-NEVADA STATELINE OR PRIMM AND
SEARCHLIGHT AREAS BY LATER THIS MORNING. SO WE COULD SEE A FEW
SHOWERS AND POSSIBLY A THUNDERSTORM ADVANCE TOWARD THE LAS VEGAS
VALLEY BY NOON AT THE LATEST. IN THE SOUTHERN SIERRA WE COULD AGAIN
SEE SNOW ABOVE 10,000 FEET THIS MORNING WITH LIGHT ACCUMULATIONS
POSSIBLE.
ADDITIONAL SHOWERS AND THUNDERSTORMS SHOULD GET GOING ACROSS
LINCOLN, CLARK, MOHAVE AND CENTRAL NYE COUNTIES AS THIS WAVE HEADS
EAST FROM VERY LATE THIS MORNING INTO THIS AFTERNOON AND EVENING
WITH ACTIVITY ENDING FROM WEST TO EAST BEHIND THE WAVE. THE MAIN
THREAT TODAY ACROSS THE AREA WITH SHOWERS AND THUNDERSTORMS WILL BE
GUSTY WINDS DUE TO THE BELT OF STRONG WINDS ALOFT COURTESY OF THE
JET OVERHEAD THAT COULD BE MIXED DOWN TO THE SURFACE. THE DRY LOW-
LEVELS ESPECIALLY FROM LAS VEGAS ON WEST WILL FAVOR TRANSPORTING
THIS MOMENTUM DOWN TO THE SURFACE. WE CANNOT RULE OUT FLASH FLOODING
EITHER IN ANY STRONGER OR TRAINING STORMS. HOWEVER, GIVEN THE STRONG
WINDS ALOFT SHOWERS AND THUNDERSTORMS WILL MOVE QUICKLY TODAY
MEANING MOST WILL NOT BE ABLE TO DROP MUCH RAIN.
WINDS WILL ALSO BE A CONCERN TODAY AWAY FROM SHOWERS AND
THUNDERSTORMS AS A 60 KT+ JET REMAINS OVERHEAD AND THE WINDFIELDS
AGAIN ALIGN FROM THE SOUTHWEST. THE WIND ADVISORY LOOKS BEST TODAY
FOR WESTERN CLARK AND SOUTHERN NYE COUNTIES ESPECIALLY THIS
AFTERNOON AND EVENING IN THE HIGHWAY 95 CORRIDOR. FURTHER SOUTH, THE
HRRR AND NMM-GFS 4 KM MODELS BOTH TRY TO DEVELOP A DOWNSLOPE WIND
EVENT LATER THIS MORNING OFF THE EASTERN AND NORTHEASTERN SLOPES OF
THE SPRING MOUNTAINS AND BRING THESE WINDS INTO THE FAR WEST SIDE OF
LAS VEGAS. THUS THE WIND ADVISORY WAS LEFT OUT FOR THIS. MOST OF LAS
VEGAS WILL NOT SEE GUSTS TO 40 MPH THIS AFTERNOON EXCEPT POSSIBLY
NEAR THE I-15 GAP AREA BETWEEN SOUTHERN HIGHLANDS AND SEVEN HILLS
AND IN AND NEAR ANY WINDIER SHOWERS AND THUNDERSTORMS.
THE FINAL WAVE OF ENERGY ROTATES THROUGH THE BASE OF THE TROUGH ON
WEDNESDAY AND WILL MAINLY FOCUS SHOWERS AND THUNDERSTORMS OVER THE
SOUTHERN GREAT BASIN AND IN EASTERN AND NORTHERN MOHAVE COUNTY WHERE
MOISTURE HAS YET TO GET FLUSHED OUT. SHOWERS MAY LINGER IN NORTHERN
LINCOLN COUNTY UNTIL LATE WEDNESDAY NIGHT. GUSTY SOUTHWEST WINDS
WILL CONTINUE BUT LOOK BELOW ADVISORY LEVELS OVERALL.
THURSDAY LOOKS DRY AND LESS WINDY WITH JUST SOME HIGH CLOUDS PASSING
ON THROUGH FROM WEST TO EAST.
TEMPS WILL REMAIN BELOW NORMAL THROUGH THURSDAY. GIVEN HIGHS IN
RECENT DAYS A TREND TOWARD THE WARMER GUIDANCE WAS FAVORED. THURSDAY
MORNING COULD BE THE FIRST 60 DEGREE LOW IN LAS VEGAS AT MCCARRAN
SINCE THE 67 ON JUNE 6TH.
.LONG TERM...FRIDAY THROUGH TUESDAY.
THE LONG TERM PERIOD BEGINS WITH WEAK TROUGHING ACROSS THE ENTIRE
FORECAST AREA BEHIND A VIGOROUS SHORTWAVE TROUGH THAT WILL BREAK
DOWN THE CURRENT TROUGH WEST/RIDGE EAST REGIME ACROSS THE LOWER 48.
DRY AIR BEHIND THE AFOREMENTIONED SHORTWAVE TROUGH WILL SPELL DRY
AND BENIGN WEATHER FOR THE ENTIRE PERIOD. THE 00Z OPERATIONAL MODELS
AND THEIR ASSOCIATED ENSEMBLES ARE IN GOOD AGREEMENT IN HIGH
PRESSURE OVER THE PACIFIC OCEAN AMPLIFYING THE OVERALL FLOW AND
KEEPING WEAK TROUGHING IN PLACE OVER THE FORECAST AREA THROUGH
SUNDAY. A WEAK SHORTWAVE WILL HELP TO KICK THE TROUGH EASTWARD
MONDAY...ALLOWING THE SUBTROPICAL RIDGE TO BUILD BACK INTO THE
DESERT SOUTHWEST. WHILE THE ONLY TRUE CHANGE IN THE STATUS QUO OF
WEATHER WILL BE WARMING TEMPERATURES ACROSS THE FORECAST AREA...IT
MAY SET THE STAGE FOR ANOTHER MOISTURE SURGE EARLY TO MID-NEXT
WEEK...AS MOISTURE FROM A TROPICAL WAVE CURRENTLY LOCATED NEAR 15N
108W MAY GET PULLED NORTHWARD INTO THE REGION. THIS WILL BE
DEPENDENT ON THE TIMING OF A POTENTIAL SHORTWAVE FROM THE GULF OF
ALASKA BRUSHING ACROSS THE NORTHERN GREAT BASIN TOWARD MID-WEEK.
THIS WILL BE SOMETHING TO WATCH IN THE COMING DAYS...AS THE
EVOLUTION AND TIMING OF EACH FEATURE WILL BE VITAL TO THE RESULTANT
WEATHER ACROSS THE REGION TOWARD MID-NEXT WEEK.
TEMPERATURE-WISE...EXPECT AFTERNOON HIGHS TO WARM FROM NEAR AVERAGE
ON FRIDAY TO SEVERAL DEGREES ABOVE AVERAGE BY THE BEGINNING OF NEXT
WEEK AS UPPER LEVEL RIDGING MAKES A RETURN TO THE AREA.
&&
.AVIATION...FOR MCCARRAN...SOUTHWEST WINDS WILL CONTINUE AOA 10KTS
OVERNIGHT WITH PERIODIC GUSTS BETWEEN 20-25KTS AT THE TERMINAL.
TODAY LOOKS TO BE ANOTHER WINDY DAY...WITH SOUTHWEST WINDS BETWEEN
15-20 KTS AND GUSTS AS HIGH AS 30-35 KTS AT TIMES. SHRA CHANCES AT
THE TERMINAL WILL INCREASE AFTER 18Z TODAY WITH CHANCES LASTING INTO
THE EVENING HOURS. GIVEN THE ENVIRONMENT...THE MAIN CONCERN WITH
THIS ACTIVITY WILL BE POSSIBLE GUSTY AND ERRATIC WIND SHIFTS IN AND
AROUND THIS ACTIVITY. GUSTY RIDGETOP WINDS OVER THE SPRING MOUNTAINS
THIS MORNING COULD MAKE MECHANICAL TURBULENCE POSSIBLE BEFORE WINDS
DECREASE LATER THIS MORNING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ANOTHER DAY OF GUSTY SOUTH TO SOUTHWEST WINDS ARE
EXPECTED ACROSS THE REGION. SOUTH TO SOUTHWEST WINDS OF 20-25KTS
WITH GUSTS BETWEEN 30-35KTS ARE EXPECTED. ISO TO SCT SHRA/TSRA ARE
POSSIBLE FROM LATE MORNING THROUGH THIS EVENING. GUSTY AND ERRATIC
WIND SHIFTS WILL BE POSSIBLE IN AND AROUND THIS ACTIVITY. STRONG
RIDGETOP WINDS COULD CAUSE AREAS OF MECHANICAL TURBULENCE OVER AND
ESPECIALLY DOWNWIND OF HIGHER TERRAIN. OCCASIONAL AREAS OF HZ AND FU
ARE POSSIBLE IN AND NEAR KBIH DUE TO FIRES IN THE REGION.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
AT THIS TIME. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM...STACHELSKI
LONG TERM/AVIATION...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
327 AM PDT TUE SEP 15 2015
.SYNOPSIS...A TROUGH OF LOW PRESSURE COMBINED WITH SEVERAL WAVES OF
ENERGY WITHIN IT WILL RESULT IN SHOWERS AND THUNDERSTORMS AROUND AS
WELL AS GUSTY WINDS ACROSS THE AREA TODAY AND TO A LESSER EXTENT ON
WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO MOHAVE,
LINCOLN AND CENTRAL NYE COUNTIES ON WEDNESDAY. OTHERWISE EXPECT DRY
CONDITIONS FROM THURSDAY THROUGH NEXT MONDAY. TEMPERATURES WILL
REMAIN BELOW NORMAL THROUGH THURSDAY THEN WARM BACK ABOVE NORMAL BY
THE WEEKEND.
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT.
SHOWERS AND A FEW THUNDERSTORMS ARE STILL GOING ACROSS NORTHERN
MOHAVE AND FAR NORTHEAST CLARK COUNTIES EARLY THIS MORNING AS A WEAK
MID-LEVEL DISTURBANCE LIFTS NORTHEAST ACROSS THIS AREA. OUR
ATTENTION NOW TURNS TOWARD THE COAST OF SOCAL AS WELL AS THE SAN
JOAQUIN VALLEY AND SOUTHERN SIERRA WHERE SHOWERS WERE ADVANCING ON
EAST. THIS ACTIVITY WILL HEAD INTO INYO AND SAN BERNARDINO COUNTIES
THIS MORNING AS ANOTHER WAVE OF ENERGY ROTATES THROUGH THE BASE OF
THE TROUGH AIDED BY LIFT FROM A SPLIT JET STREAM OVER THE SOUTHERN
HALF OF CALIFORNIA. THE HRRR MODEL FORECASTS THE SOCAL SHOWERS TO
MAKE HEADWAY TOWARD THE CALIFORNIA-NEVADA STATELINE OR PRIMM AND
SEARCHLIGHT AREAS BY LATER THIS MORNING. SO WE COULD SEE A FEW
SHOWERS AND POSSIBLY A THUNDERSTORM ADVANCE TOWARD THE LAS VEGAS
VALLEY BY NOON AT THE LATEST. IN THE SOUTHERN SIERRA WE COULD AGAIN
SEE SNOW ABOVE 10,000 FEET THIS MORNING WITH LIGHT ACCUMULATIONS
POSSIBLE.
ADDITIONAL SHOWERS AND THUNDERSTORMS SHOULD GET GOING ACROSS
LINCOLN, CLARK, MOHAVE AND CENTRAL NYE COUNTIES AS THIS WAVE HEADS
EAST FROM VERY LATE THIS MORNING INTO THIS AFTERNOON AND EVENING
WITH ACTIVITY ENDING FROM WEST TO EAST BEHIND THE WAVE. THE MAIN
THREAT TODAY ACROSS THE AREA WITH SHOWERS AND THUNDERSTORMS WILL BE
GUSTY WINDS DUE TO THE BELT OF STRONG WINDS ALOFT COURTESY OF THE
JET OVERHEAD THAT COULD BE MIXED DOWN TO THE SURFACE. THE DRY LOW-
LEVELS ESPECIALLY FROM LAS VEGAS ON WEST WILL FAVOR TRANSPORTING
THIS MOMENTUM DOWN TO THE SURFACE. WE CANNOT RULE OUT FLASH FLOODING
EITHER IN ANY STRONGER OR TRAINING STORMS. HOWEVER, GIVEN THE STRONG
WINDS ALOFT SHOWERS AND THUNDERSTORMS WILL MOVE QUICKLY TODAY
MEANING MOST WILL NOT BE ABLE TO DROP MUCH RAIN.
WINDS WILL ALSO BE A CONCERN TODAY AWAY FROM SHOWERS AND
THUNDERSTORMS AS A 60 KT+ JET REMAINS OVERHEAD AND THE WINDFIELDS
AGAIN ALIGN FROM THE SOUTHWEST. THE WIND ADVISORY LOOKS BEST TODAY
FOR WESTERN CLARK AND SOUTHERN NYE COUNTIES ESPECIALLY THIS
AFTERNOON AND EVENING IN THE HIGHWAY 95 CORRIDOR. FURTHER SOUTH, THE
HRRR AND NMM-GFS 4 KM MODELS BOTH TRY TO DEVELOP A DOWNSLOPE WIND
EVENT LATER THIS MORNING OFF THE EASTERN AND NORTHEASTERN SLOPES OF
THE SPRING MOUNTAINS AND BRING THESE WINDS INTO THE FAR WEST SIDE OF
LAS VEGAS. THUS THE WIND ADVISORY WAS LEFT OUT FOR THIS. MOST OF LAS
VEGAS WILL NOT SEE GUSTS TO 40 MPH THIS AFTERNOON EXCEPT POSSIBLY
NEAR THE I-15 GAP AREA BETWEEN SOUTHERN HIGHLANDS AND SEVEN HILLS
AND IN AND NEAR ANY WINDIER SHOWERS AND THUNDERSTORMS.
THE FINAL WAVE OF ENERGY ROTATES THROUGH THE BASE OF THE TROUGH ON
WEDNESDAY AND WILL MAINLY FOCUS SHOWERS AND THUNDERSTORMS OVER THE
SOUTHERN GREAT BASIN AND IN EASTERN AND NORTHERN MOHAVE COUNTY WHERE
MOISTURE HAS YET TO GET FLUSHED OUT. SHOWERS MAY LINGER IN NORTHERN
LINCOLN COUNTY UNTIL LATE WEDNESDAY NIGHT. GUSTY SOUTHWEST WINDS
WILL CONTINUE BUT LOOK BELOW ADVISORY LEVELS OVERALL.
THURSDAY LOOKS DRY AND LESS WINDY WITH JUST SOME HIGH CLOUDS PASSING
ON THROUGH FROM WEST TO EAST.
TEMPS WILL REMAIN BELOW NORMAL THROUGH THURSDAY. GIVEN HIGHS IN
RECENT DAYS A TREND TOWARD THE WARMER GUIDANCE WAS FAVORED. THURSDAY
MORNING COULD BE THE FIRST 60 DEGREE LOW IN LAS VEGAS AT MCCARRAN
SINCE THE 67 ON JUNE 6TH.
.LONG TERM...FRIDAY THROUGH TUESDAY.
THE LONG TERM PERIOD BEGINS WITH WEAK TROUGHING ACROSS THE ENTIRE
FORECAST AREA BEHIND A VIGOROUS SHORTWAVE TROUGH THAT WILL BREAK
DOWN THE CURRENT TROUGH WEST/RIDGE EAST REGIME ACROSS THE LOWER 48.
DRY AIR BEHIND THE AFOREMENTIONED SHORTWAVE TROUGH WILL SPELL DRY
AND BENIGN WEATHER FOR THE ENTIRE PERIOD. THE 00Z OPERATIONAL MODELS
AND THEIR ASSOCIATED ENSEMBLES ARE IN GOOD AGREEMENT IN HIGH
PRESSURE OVER THE PACIFIC OCEAN AMPLIFYING THE OVERALL FLOW AND
KEEPING WEAK TROUGHING IN PLACE OVER THE FORECAST AREA THROUGH
SUNDAY. A WEAK SHORTWAVE WILL HELP TO KICK THE TROUGH EASTWARD
MONDAY...ALLOWING THE SUBTROPICAL RIDGE TO BUILD BACK INTO THE
DESERT SOUTHWEST. WHILE THE ONLY TRUE CHANGE IN THE STATUS QUO OF
WEATHER WILL BE WARMING TEMPERATURES ACROSS THE FORECAST AREA...IT
MAY SET THE STAGE FOR ANOTHER MOISTURE SURGE EARLY TO MID-NEXT
WEEK...AS MOISTURE FROM A TROPICAL WAVE CURRENTLY LOCATED NEAR 15N
108W MAY GET PULLED NORTHWARD INTO THE REGION. THIS WILL BE
DEPENDENT ON THE TIMING OF A POTENTIAL SHORTWAVE FROM THE GULF OF
ALASKA BRUSHING ACROSS THE NORTHERN GREAT BASIN TOWARD MID-WEEK.
THIS WILL BE SOMETHING TO WATCH IN THE COMING DAYS...AS THE
EVOLUTION AND TIMING OF EACH FEATURE WILL BE VITAL TO THE RESULTANT
WEATHER ACROSS THE REGION TOWARD MID-NEXT WEEK.
TEMPERATURE-WISE...EXPECT AFTERNOON HIGHS TO WARM FROM NEAR AVERAGE
ON FRIDAY TO SEVERAL DEGREES ABOVE AVERAGE BY THE BEGINNING OF NEXT
WEEK AS UPPER LEVEL RIDGING MAKES A RETURN TO THE AREA.
&&
.AVIATION...FOR MCCARRAN...SOUTHWEST WINDS WILL CONTINUE AOA 10KTS
OVERNIGHT WITH PERIODIC GUSTS BETWEEN 20-25KTS AT THE TERMINAL.
TODAY LOOKS TO BE ANOTHER WINDY DAY...WITH SOUTHWEST WINDS BETWEEN
15-20 KTS AND GUSTS AS HIGH AS 30-35 KTS AT TIMES. SHRA CHANCES AT
THE TERMINAL WILL INCREASE AFTER 18Z TODAY WITH CHANCES LASTING INTO
THE EVENING HOURS. GIVEN THE ENVIRONMENT...THE MAIN CONCERN WITH
THIS ACTIVITY WILL BE POSSIBLE GUSTY AND ERRATIC WIND SHIFTS IN AND
AROUND THIS ACTIVITY. GUSTY RIDGETOP WINDS OVER THE SPRING MOUNTAINS
THIS MORNING COULD MAKE MECHANICAL TURBULENCE POSSIBLE BEFORE WINDS
DECREASE LATER THIS MORNING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ANOTHER DAY OF GUSTY SOUTH TO SOUTHWEST WINDS ARE
EXPECTED ACROSS THE REGION. SOUTH TO SOUTHWEST WINDS OF 20-25KTS
WITH GUSTS BETWEEN 30-35KTS ARE EXPECTED. ISO TO SCT SHRA/TSRA ARE
POSSIBLE FROM LATE MORNING THROUGH THIS EVENING. GUSTY AND ERRATIC
WIND SHIFTS WILL BE POSSIBLE IN AND AROUND THIS ACTIVITY. STRONG
RIDGETOP WINDS COULD CAUSE AREAS OF MECHANICAL TURBULENCE OVER AND
ESPECIALLY DOWNWIND OF HIGHER TERRAIN. OCCASIONAL AREAS OF HZ AND FU
ARE POSSIBLE IN AND NEAR KBIH DUE TO FIRES IN THE REGION.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
AT THIS TIME. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM...STACHELSKI
LONG TERM/AVIATION...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
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AREA FORECAST DISCUSSION
NWS BISMARCK ND
936 AM CDT TUE SEP 15 2015
.UPDATE...
ISSUED AT 927 AM CDT TUE SEP 15 2015
LOW PRESSURE OVER SOUTHEAST MONTANA INTO NORTH CENTRAL SOUTH
DAKOTA WITH A WARM FRONT NORTHEAST FROM HERE INTO NORTHERN
MINNESOTA. A GOOD PORTION OF CENTRAL AND WESTERN NORTH DAKOTA
REMAIN NORTH OF THE FRONT THIS MORNING...THUS LOW STRATUS AND FOG
REMAIN AN ISSUE THROUGH THE MORNING HOURS. HAVE ADJUSTED WEATHER
AND SKY COVER TO INCREASE CLOUD FOG COVERAGE THROUGH THIS
MORNING...ESPECIALLY ACROSS THE NORTH. SHOWERS ACROSS CENTRAL
NORTH DAKOTA LIFTING NORTHEAST. THERE IS SOME SLIGHT TO MODERATE
INSTABILITY ALOFT TODAY WITH STRONG BULK SHEAR. THE WAVE LIFTING
THROUGH CENTRAL NORTH DAKOTA AT THIS TIME IS PRODUCING ENOUGH LIFT
TO OVERCOME CONVECTIVE INHIBITION...AND THERE HAVE BEEN A FEW
LIGHTING STRIKES WITH THIS CONVECTION. HAVE ADDED A MENTION OF
THUNDER THIS MORNING.
UPDATE ISSUED AT 737 AM CDT TUE SEP 15 2015
SENT OUT A QUICK UPDATE TO ADD A MENTION OF FOG TO PORTIONS OF THE
SOUTH CENTRAL THIS MORNING.
UPDATE ISSUED AT 638 AM CDT TUE SEP 15 2015
LATEST RADARS SHOW THE AREA OF SHOWERS CONTINUES TO MOVE NORTH
THROUGH WESTERN NORTH DAKOTA. PATCHY FOG ALSO EXTENDS ACROSS THE JAMES
RIVER VALLEY. THE FOG SHOULD LIFT AROUND SUNRISE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE MAIN FOCUS FOR THE SHORT TERM WILL BE THUNDERSTORM CHANCES.
A SURFACE LOW WILL CONTINUE TO PUSH OUT OF EASTERN MONTANA AND
INTO WESTERN NORTH DAKOTA TODAY...DRAGGING WITH IT A WARM FRONT
ACROSS THE REGION. SCATTERED SHOWERS ARE POSSIBLE ALONG THE WARM
FRONT THIS MORNING. BY THIS AFTERNOON MOST OF WESTERN AND CENTRAL
NORTH DAKOTA WILL BE IN THE WARM SECTOR. TEMPERATURES ARE EXPECTED
TO RISE INTO THE MID TO UPPER 80S ACROSS MOST OF THE REGION.
STRONG MOISTURE ADVECTION WILL OCCUR AT THE SURFACE WITH DEWPOINTS
IN THE MID 60S LIKELY. HOWEVER...RELATIVELY WARM AND DRY MID-
LEVELS (AS SEEN IN RAP AND NAM FORECAST SOUNDINGS) COULD LIMIT
AFTERNOON CONVECTION. IF THUNDERSTORMS DO DEVELOP THIS
AFTERNOON...THEY COULD BECOME STRONG WITH GUSTY WINDS AND SMALL
HAIL...WITH CAPE AROUND 1000 J/KG...30+ KNOTS OF SHEAR AND STEEP
LAPSE RATES FORECAST. THIS EVENING WILL SEE THE BEST CHANCE FOR
THUNDERSTORMS WHEN UPPER LEVEL SUPPORT ARRIVES VIA A SHORT WAVE
TROUGH AND JET STREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE EXTENDED BEGINS WEDNESDAY AND FEATURES A LONGWAVE TROUGH OVER
THE WESTERN US WITH A DOWNSTREAM BROAD RIDGE OVER THE GREAT
LAKES. THIS PLACES THE NORTHERN PLAINS IN A SOUTHWEST FLOW REGIME
ALOFT THAT WILL BRING SHORTWAVE ENERGY INTO THE NORTHERN PLAINS
BY WEDNESDAY NIGHT AND THURSDAY. THIS WILL END UP BEING THE MOST
ACTIVE PERIOD FOR THUNDERSTORMS. AFTER THE TROUGH AXIS MOVES
THROUGH A SECOND SHORTWAVE WILL BRUSH THE SOUTHERN SECTIONS OF THE
STATE ON FRIDAY. OTHERWISE A DRY PERIOD WITH GRADUAL MODERATING
TEMPERATURES WILL TAKE HOLD FOR THE WEEKEND.
MODELS APPEAR IN GOOD AGREEMENT ON THESE GENERAL FEATURES. A COLD
FRONT ASSOCIATED WITH THE SHORT WAVE WILL MOVE ACROSS THE STATE
WEDNESDAY AND WEDNESDAY NIGHT AND BE THE FOCUS FOR THUNDERSTORMS.
COOLER AIR BEHIND THE FRONT THURSDAY WILL MEAN HIGHS ONLY IN THE
UPPER 50S NORTH TO THE 70S SOUTHEAST. THE BEST CHANCE FOR
PRECIPITATION WILL BE ACROSS THE NORTH WITH LIKELY TO DEFINITE
POPS BY WEDNEDAY NIGHT. LINGERING SHOWERS WILL REMAIN ACROSS THE
NORTH AND EAST THURSDAY. CLEARING SKIES WITH A SLOW MODERATION IN
TEMPERATURES FOR THE WEEKEND THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 927 AM CDT TUE SEP 15 2015
MVFR TO IFR CONDITIONS REMAIN ACROSS MOST OF WESTERN AND CENTRAL
NORTH DAKOTA THIS MORNING. EXPECT CONDITIONS TO SLOWLY IMPROVE
FROM SOUTH TO NORTH LATE MORNING AND AFTERNOON AS A WARM FRONT
LIFTS NORTHWARD. ALSO SCATTERED SHOWERS AND THUNDERSTORMS LIFTING
NORTHWARD THROUGH CENTRAL NORTH DAKOTA. WILL NEED TO MONITOR FOR
POSSIBLE VCTS AT KBIS/MOT YET THIS MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...WAA
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
ISSUED BY NATIONAL WEATHER SERVICE BISMARCK ND
924 AM CDT TUE SEP 15 2015
.UPDATE...
ISSUED AT 924 AM CDT TUE SEP 15 2015
LATEST SURFACE ANALYSIS SHOWS PATCHY FOG CONTINUING OVER THE
DEVILS LAKE BASIN AS A WARM FRONT REMAINS JUST TO THE SOUTH NEAR
GRAND FORKS. EASTERLY WINDS ADVECTING IN DEWPOINTS INTO THE MID
AND UPPER 50S RESULTING IN TEMPERATURE/DEW POINT DEPRESSIONS NEAR
OR AT ZERO. LATEST HRRR CIG/VSBY FORECAST SHOWS IMPROVING CIGS
THROUGH 18Z...LIFTING TO BETWEEN 500FT AND 1000FT BY 18Z BEFORE
SCATTERING OUT. WITH LOCAL/REGIONAL RADAR SHOWING WEAK
REFLECTIVITY`S APPROACHING THE DEVILS LAKE AREA...HAVE MESHED IN
WITH BISMARCK TO ADD ISOLATED SHOWERS IN THE FAR NORTH THROUGH
18Z. UPDATED SKY COVER TO REFLECT CURRENT CONDITIONS IN THE FOG
REGIME AREA MENTIONED ABOVE. REST OF FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 630 AM CDT TUE SEP 15 2015
ADDED SOME PATCHY FOG TO THE DVL BASIN AREA OTHERWISE NO CHANGES
THIS UPDATE PERIOD.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 315 AM CDT TUE SEP 15 2015
FORECAST CHALLENGES WILL BE TEMPERATURES AND PCPN CHANCES. MODELS
DIFFER ON TIMING OF APPROACHING BOUNDARY AND SURFACE LOW POSITION
SO NOT A GREAT DEAL OF CONFIDENCE ON STORM CHANCES LATER TODAY.
WATER VAPOR INDICATING TWO SHORTWAVES WHICH WILL BE LIFTING NE
THROUGH THE N CENTRAL US NEXT 18 HOURS OR SO. LEAD WAVE OVER N
CENTRAL WYO WILL LIFT THROUGH THE W DAKOTAS THIS MORNING INTO
EARLY AFTERNOON. SECOND WAVE OVER S UTAH WILL REACH THE REGION
THIS EVENING. DOUBT LEAD WAVE WILL HAVE MUCH OF AN IMPACT ON US
BASED ON TIMING. THE LATER WAVE LOOKS TO HAVE A BETTER CHANCE TO
PROVIDE SUPPORT FOR POSSIBLE STORMS. ON THE SURFACE...WARM FRONTAL
BOUNDARY WILL CONTINUE TO LIFT NORTH AND SHOULD BE NORTH OF THE
INTERNATIONAL BORDER BY AFTERNOON. BY LATE AFTERNOON MODELS DIFFER
ON POSITION OF SURFACE LOW AND TRAILING COLD FRONT. CONSENSUS FROM
SHORT RANGE MODEL/CAM GUIDANCE PUTS SURFACE LOW OVER
CENTRAL/WESTERN ND AT 00Z. THIS POSITION COMBINED WITH STRONG
CAPPING IN WARM SECTOR OVER US DOES NOT APPEAR FAVORABLE FOR ANY
CONVECTION AND HAVE KEPT FA DRY INTO EARLY EVENING. WITH THERMAL
RIDGE AXIS NOSING INTO THE FA WILL SEE VERY WARM TEMPERATURES
TODAY ALONG WITH BREEZY/WINDY SOUTH WINDS.
AS ABOVE MENTIONED WAVE LIFTS NE AND COLD FRONT PROPAGATES ACROSS
THE FA TONIGHT WILL SEE SLIGHTLY BETTER CHANCES FOR THUNDERSTORMS
LATER IN THE EVENING AND OVERNIGHT. TEMPERATURES SHOULD REMAIN
FAIRLY MILD WITH LATE ARRIVAL OF ANY COLD ADVECTION.
AS WAVE DEPARTS BRUNT OF WEDNESDAY SHOULD REMAIN DRY. SE HALF OF
FA SHOULD REMAIN WARM WITH TEMPERATURES CLOSER TO AVERAGE OVER THE
NW HALF.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 AM CDT TUE SEP 15 2015
MORE POTENT WAVE WILL LIFT NE INTO THE FA LATE WEDNESDAY NIGHT
INTO THURSDAY FOR BETTER PCPN CHANCES. KEPT HIGHER POPS GOING BUT
DELAYED TIMING.
WAVE PUSHES THROUGH BY THURSDAY EVENING FOR DRY AND COOLER
CONDITIONS.
MODELS INDICATE A SOUTHWEST FLOW
PATTERN ALOFT AND AN ASSOCIATED SFC LOW TRANSITING THE NORTHERN
TIER...BRINGING A CHANCE FOR CONVECTION THU MORNING. ECMWF AND GFS
BOTH SHOWING SHOWALTERS RISE RAPIDLY BEHIND FRONTAL PASSAGE BY
NOONTIME THURSDAY...AND HAVE CHANGED AFTN P-TYPE FROM TSRA TO SHRA.
A MORE ZONAL PATTERN DEVELOPS FOR THU NIGHT INTO FRI...BRINGING SOME
LOW POPS FOR THE END OF THE WORK WEEK THAT WILL BE DEPENDENT ON
TIMING OF WEAK WAVES IN THE ZONAL FLOW. AN UPPER RIDGE DEVELOPS OVER
THE WEEKEND AND SHOULD BRING A DRY WEEKEND WITH SEASONALLY WARM
TEMPERATURES INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 924 AM CDT TUE SEP 15 2015
A WARM FRONT WAS LOCATED FROM NEAR KJMS/JAMESTOWN ND INTO
KGFK/GRAND FORKS. VFR CIGS/VSBYS SOUTH OF THE WARM FRONT WITH
LIFR/IFR CIGS/VSBYS AT KDVL. CIGS/VSBYS WILL CONTINUE TO LIFT AND
IMPROVE THROUGH 18Z AND HAVE ADJUSTED THE TAF IN THIS DIRECTION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SIMOSKO
SHORT TERM...VOELKER
LONG TERM...SPEICHER/VOELKER
AVIATION...SIMOSKO
AREA FORECAST DISCUSSION
NWS BISMARCK ND
738 AM CDT TUE SEP 15 2015
.UPDATE...
ISSUED AT 737 AM CDT TUE SEP 15 2015
SENT OUT A QUICK UPDATE TO ADD A MENTION OF FOG TO PORTIONS OF THE
SOUTH CENTRAL THIS MORNING.
UPDATE ISSUED AT 638 AM CDT TUE SEP 15 2015
LATEST RADARS SHOW THE AREA OF SHOWERS CONTINUES TO MOVE NORTH
THROUGH WESTERN NORTH DAKOTA. PATCHY FOG ALSO EXTENDS ACROSS THE JAMES
RIVER VALLEY. THE FOG SHOULD LIFT AROUND SUNRISE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE MAIN FOCUS FOR THE SHORT TERM WILL BE THUNDERSTORM CHANCES.
A SURFACE LOW WILL CONTINUE TO PUSH OUT OF EASTERN MONTANA AND
INTO WESTERN NORTH DAKOTA TODAY...DRAGGING WITH IT A WARM FRONT
ACROSS THE REGION. SCATTERED SHOWERS ARE POSSIBLE ALONG THE WARM
FRONT THIS MORNING. BY THIS AFTERNOON MOST OF WESTERN AND CENTRAL
NORTH DAKOTA WILL BE IN THE WARM SECTOR. TEMPERATURES ARE EXPECTED
TO RISE INTO THE MID TO UPPER 80S ACROSS MOST OF THE REGION.
STRONG MOISTURE ADVECTION WILL OCCUR AT THE SURFACE WITH DEWPOINTS
IN THE MID 60S LIKELY. HOWEVER...RELATIVELY WARM AND DRY MID-
LEVELS (AS SEEN IN RAP AND NAM FORECAST SOUNDINGS) COULD LIMIT
AFTERNOON CONVECTION. IF THUNDERSTORMS DO DEVELOP THIS
AFTERNOON...THEY COULD BECOME STRONG WITH GUSTY WINDS AND SMALL
HAIL...WITH CAPE AROUND 1000 J/KG...30+ KNOTS OF SHEAR AND STEEP
LAPSE RATES FORECAST. THIS EVENING WILL SEE THE BEST CHANCE FOR
THUNDERSTORMS WHEN UPPER LEVEL SUPPORT ARRIVES VIA A SHORT WAVE
TROUGH AND JET STREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE EXTENDED BEGINS WEDNESDAY AND FEATURES A LONGWAVE TROUGH OVER
THE WESTERN US WITH A DOWNSTREAM BROAD RIDGE OVER THE GREAT
LAKES. THIS PLACES THE NORTHERN PLAINS IN A SOUTHWEST FLOW REGIME
ALOFT THAT WILL BRING SHORTWAVE ENERGY INTO THE NORTHERN PLAINS
BY WEDNESDAY NIGHT AND THURSDAY. THIS WILL END UP BEING THE MOST
ACTIVE PERIOD FOR THUNDERSTORMS. AFTER THE TROUGH AXIS MOVES
THROUGH A SECOND SHORTWAVE WILL BRUSH THE SOUTHERN SECTIONS OF THE
STATE ON FRIDAY. OTHERWISE A DRY PERIOD WITH GRADUAL MODERATING
TEMPERATURES WILL TAKE HOLD FOR THE WEEKEND.
MODELS APPEAR IN GOOD AGREEMENT ON THESE GENERAL FEATURES. A COLD
FRONT ASSOCIATED WITH THE SHORT WAVE WILL MOVE ACROSS THE STATE
WEDNESDAY AND WEDNESDAY NIGHT AND BE THE FOCUS FOR THUNDERSTORMS.
COOLER AIR BEHIND THE FRONT THURSDAY WILL MEAN HIGHS ONLY IN THE
UPPER 50S NORTH TO THE 70S SOUTHEAST. THE BEST CHANCE FOR
PRECIPITATION WILL BE ACROSS THE NORTH WITH LIKELY TO DEFINITE
POPS BY WEDNEDAY NIGHT. LINGERING SHOWERS WILL REMAIN ACROSS THE
NORTH AND EAST THURSDAY. CLEARING SKIES WITH A SLOW MODERATION IN
TEMPERATURES FOR THE WEEKEND THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 638 AM CDT TUE SEP 15 2015
AT 6 AM CDT...A WARM FRONT EXTENDED FROM SURFACE LOW PRESSURE IN
SOUTH CENTRAL NORTH DAKOTA INTO THE NORTHEAST. SOUTHEAST FLOW
OVER THE WARM FRONT WAS FORMING AN AREA OF IFR CEILINGS THAT
EXTENDED FROM DEVILS LAKE TO NEAR MINOT. THIS AREA WILL PERSIST
INTO THE AFTERNOON. MVFR TO IFR CEILINGS KMOT WITH MVFR POSSIBLE
KDIK-KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
649 AM CDT TUE SEP 15 2015
.UPDATE...
ISSUED AT 638 AM CDT TUE SEP 15 2015
LATEST RADARS SHOW THE AREA OF SHOWERS CONTINUES TO MOVE NORTH
THROUGH WESTERN NORTH DAKOTA. PATCHY FOG ALSO EXTENDS ACROSS THE JAMES
RIVER VALLEY. THE FOG SHOULD LIFT AROUND SUNRISE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE MAIN FOCUS FOR THE SHORT TERM WILL BE THUNDERSTORM CHANCES.
A SURFACE LOW WILL CONTINUE TO PUSH OUT OF EASTERN MONTANA AND
INTO WESTERN NORTH DAKOTA TODAY...DRAGGING WITH IT A WARM FRONT
ACROSS THE REGION. SCATTERED SHOWERS ARE POSSIBLE ALONG THE WARM
FRONT THIS MORNING. BY THIS AFTERNOON MOST OF WESTERN AND CENTRAL
NORTH DAKOTA WILL BE IN THE WARM SECTOR. TEMPERATURES ARE EXPECTED
TO RISE INTO THE MID TO UPPER 80S ACROSS MOST OF THE REGION.
STRONG MOISTURE ADVECTION WILL OCCUR AT THE SURFACE WITH DEWPOINTS
IN THE MID 60S LIKELY. HOWEVER...RELATIVELY WARM AND DRY MID-
LEVELS (AS SEEN IN RAP AND NAM FORECAST SOUNDINGS) COULD LIMIT
AFTERNOON CONVECTION. IF THUNDERSTORMS DO DEVELOP THIS
AFTERNOON...THEY COULD BECOME STRONG WITH GUSTY WINDS AND SMALL
HAIL...WITH CAPE AROUND 1000 J/KG...30+ KNOTS OF SHEAR AND STEEP
LAPSE RATES FORECAST. THIS EVENING WILL SEE THE BEST CHANCE FOR
THUNDERSTORMS WHEN UPPER LEVEL SUPPORT ARRIVES VIA A SHORT WAVE
TROUGH AND JET STREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE EXTENDED BEGINS WEDNESDAY AND FEATURES A LONGWAVE TROUGH OVER
THE WESTERN US WITH A DOWNSTREAM BROAD RIDGE OVER THE GREAT
LAKES. THIS PLACES THE NORTHERN PLAINS IN A SOUTHWEST FLOW REGIME
ALOFT THAT WILL BRING SHORTWAVE ENERGY INTO THE NORTHERN PLAINS
BY WEDNESDAY NIGHT AND THURSDAY. THIS WILL END UP BEING THE MOST
ACTIVE PERIOD FOR THUNDERSTORMS. AFTER THE TROUGH AXIS MOVES
THROUGH A SECOND SHORTWAVE WILL BRUSH THE SOUTHERN SECTIONS OF THE
STATE ON FRIDAY. OTHERWISE A DRY PERIOD WITH GRADUAL MODERATING
TEMPERATURES WILL TAKE HOLD FOR THE WEEKEND.
MODELS APPEAR IN GOOD AGREEMENT ON THESE GENERAL FEATURES. A COLD
FRONT ASSOCIATED WITH THE SHORT WAVE WILL MOVE ACROSS THE STATE
WEDNESDAY AND WEDNESDAY NIGHT AND BE THE FOCUS FOR THUNDERSTORMS.
COOLER AIR BEHIND THE FRONT THURSDAY WILL MEAN HIGHS ONLY IN THE
UPPER 50S NORTH TO THE 70S SOUTHEAST. THE BEST CHANCE FOR
PRECIPITATION WILL BE ACROSS THE NORTH WITH LIKELY TO DEFINITE
POPS BY WEDNEDAY NIGHT. LINGERING SHOWERS WILL REMAIN ACROSS THE
NORTH AND EAST THURSDAY. CLEARING SKIES WITH A SLOW MODERATION IN
TEMPERATURES FOR THE WEEKEND THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 638 AM CDT TUE SEP 15 2015
AT 6 AM CDT...A WARM FRONT EXTENDED FROM SURFACE LOW PRESSURE IN
SOUTH CENTRAL NORTH DAKOTA INTO THE NORTHEAST. SOUTHEAST FLOW
OVER THE WARM FRONT WAS FORMING AN AREA OF IFR CEILINGS THAT
EXTENDED FROM DEVILS LAKE TO NEAR MINOT. THIS AREA WILL PERSIST
INTO THE AFTERNOON. MVFR TO IFR CEILINGS KMOT WITH MVFR POSSIBLE
KDIK-KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AJ
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
640 AM CDT TUE SEP 15 2015
.DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
SFC ANALYSIS HAS WARM FRONT JUST INLAND. AREA RADAR SHOWS ONLY A
FEW SHRA IN THE GULF OFF THE COAST FROM KLBX AND KGLS. INLAND
KCXO/KUTS/KCLL MAY HAVE A MIX OF MVFR/IFR CIGS FOR A COUPLE OF
HOURS UNTIL MXING INCREASES. MOISTURE SHOULD BE INCREASING AS THE
WARM FRONT MOVES NORTH WHICH SHOULD SUPPORT SCATTERED SHRA/TSRA
EARLY THIS AFTERNOON. BASED ON HRRR AND LATEST WRF RUNS...DELAYED
ONSET OF VCTS FOR TAFS UNTIL 17-19Z AND END AROUND 21-23Z THIS
AFTERNOON. OVERALL SHOULD HAVE VFR CIGS BUT PASSING TSRA COULD
LOWER VSBY WITH MVFR CIGS.
39
&&
.PREV DISCUSSION... /ISSUED /
DISCUSSION...
A WARM FRONT WAS LOCATED FROM NEAR KBPT TO THE SOUTH SIDE OF
HOUSTON TO COLUMBUS WILL LIKELY WASH OUT AS IT PUSHES FURTHER
INLAND THIS MORNING. THE 00Z NAM12 FORECAST THE WINDS TO GRADUALLY
TURN TO THE SOUTHEAST THROUGHOUT THE MORNING. MID LEVEL HIGH
PRESSURE WAS RIDGING ACROSS THE GULF COAST STATES INTO SE TEXAS AS
WELL. FROM ABOUT 500 MB TO 200 MB AN UPPER LEVEL TROUGH THAT WAS
OVER THE EASTERN AND COASTAL AREAS LAST EVENING WAS SHOWN BY THE
WATER VAPOR TO BE MOVING OVERHEAD THE FORECAST AREA AT 3 AM.
EXPECT THAT AS THIS TROUGH MOVES OVER THE WARM FRONT THAT A FEW
SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE...ESPECIALLY
OVER THE COASTAL COUNTIES THIS MORNING. LATER TODAY...THE MAIN
DRIVER FOR GENERATING CONVECTION WILL BE DAYTIME HEATING. THE
FORECAST SOUNDINGS SHOW LITTLE CAP BUT PW/S WILL PROBABLY STAY
BELOW 2 INCHES. THE MODELS DIFFERED IN COVERAGE...WITH THE NAM12
AND 4KM WRF HAVING LESS COVERAGE THAN THE RAP13. THINK THAT
ISOLATED COVERAGE EARLY THIS MORNING WILL BECOME MORE SCATTERED
THROUGHOUT THE REMAINDER OF THE MORNING AND THROUGH THE AFTERNOON.
AM EXPECTING LESS COVERAGE ON WEDNESDAY AS AN UPPER LEVEL HIGH
PRESSURE AREA BEGINS TO BUILD OVERHEAD...WITH THE BEST CHANCES
OVER THE SOUTHERN HALF OF THE FORECAST AREA. EXPECT THURSDAY INTO
THE WEEKEND TO BE MAINLY DRY AND HOT AS THE HIGH PRESSURE RIDGE
DEVELOPS OVERHEAD...AND TEMPERATURES WILL LIKELY REACH INTO THE
LOWER TO MID 89S OVER THE INLAND AREAS. THE RIDGE STARTS TO BREAK
DOWN EARLY NEXT WEEK AND EXPECT AT LEAST ISOLATED COVERAGE OF
SHOWERS AND THUNDERSTORMS TO BE POSSIBLE ON MONDAY.
40
MARINE...
SFC ANALYSIS AT 08Z HAS WARM FRONT JUST ONSHORE THE UPPER TEXAS
COAST THIS MORNING. SFC DEWPOINT TEMPS ARE NOW IN THE LOW/MID 70S
ALONG THE COAST WITH E/SE WINDS AROUND 15 KNOTS. WINDS SHOULD
CONTINUE TO DECREASE TODAY SO SMALL CRAFT EXERCISE CAUTIONS WILL
NOT BE NEEDED. OVERALL EXPECT E/SE WINDS OF 10-15 KNOTS FOR MUCH
OF THE REST OF THE WEEK. A EXTENDED EASTERLY FETCH OF WINDS WILL
KEEP SEAS ELEVATED IN THE OFFSHORE WATERS. SEAS SHOULD REMAIN
AROUND 3 FEET FOR THE END OF THE WEEK. THE OTHER HAZARDS WILL BE
RIP CURRENTS ALONG THE GULF FACING BEACHES DUE TO MORE EASTERLY
DIRECTED WAVES. TIDE LEVELS WILL ALSO BE ABOUT 1 FOOT ABOVE
NORMAL...POSSIBLY 1.5 FEET ABOVE NORMAL.
AN AREA OF LOW PRESSURE LOCATED OVER THE SW GULF OF MEXICO EAST OF
TAMPICO SHOULD CONTINUE TO CAUSE DISORGANIZED SHOWERS AND
THUNDERSTORMS. TROPICAL DEVELOPMENT IS NOT EXPECTED WITH THIS
SYSTEM AS IT MOVES INLAND MEXICO LATER TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 89 73 92 74 94 / 30 10 20 10 10
HOUSTON (IAH) 88 74 89 72 93 / 40 10 20 10 10
GALVESTON (GLS) 86 79 86 79 88 / 50 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
626 AM CDT TUE SEP 15 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.UPDATE...
ISSUED AT 410 AM CDT TUE SEP 15 2015
ALREADY ADDED TSRA TO PARTS OF CENTRAL AND EAST CENTRAL WISCONSIN
AN HOUR AGO BUT RADAR TRENDS SHOW A SMALL CLUSTER OF CONVECTION
OVER SOUTHERN PORTIONS OF MTW AND CALUMET COUNTIES WITH A
DEPARTING VORT AND THEN A SECOND AREA WITHE WAA PCPN WITH THE LLJ
STILL WORKING INTO CENTRAL WISCONSIN. NO RECENT LIGHTNING STRIKES
OVER CENTRAL WI BUT CONVECTION WAS SHOWING A GRADUAL DECREASE.
THE CONVECTION WAS ELEVATED.
&&
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
OVERALL DRY QUIET AND ABOVE NORMAL TEMPERATURES THROUGH MID WEEK.
EARLY THIS MORNING ISOLATED TO SCATTERED CONVECTION WAS OCCURRING
IN THE BROAD WAA SECTOR FROM SOUTHERN MINNESOTA TO THE SOUTH HALF
OF WISCONSIN. CONVECTION OVER WESTERN WISCONSIN PRIMARILY WARM
AIR ADVECTION WITH THE STRONGER LLJ...WHILE CONVECTION CENTERED
AROUND FOND DU LAC COUNTY ASSOCIATED WITH A WEAK VORT SLIDING OVER AS
PER WATER VAPOR LOOP EARLY THIS MORNING. HRRR MODEL SLIDE WEAK
CONVECTION OVER THE SOUTHERN TWO THIRDS OF THE FORECAST AREA EARLY
THIS MORNING. WILL KEEP THE ISOLD SPRINKLES GOING THIS MORNING DUE
TO FALLING FROM MID LEVEL CLOUDS BUT MONITOR FOR ANY NEEDED
MENTION OF TSRA TO THE AREA TO AROUND DAYBREAK. CONVECTION
EXPECTED TO DISSIPATE LATER MORNING AS THE VORT SLIDES EAST AND
THE WARM AIR ADVECTION MIXES OUT TO PROVIDE AN OVERALL DRY DAY.
LITTLE CHANGED IN THE FORECAST FOR TONIGHT...CONTINUED WAA IN THE
SOUTHWEST FLOW AND LLJ WILL BRING A SMALL CHANCE OF CONVECTION TO
THE NORTHWEST HALF TONIGHT. WHAT CONVECTION DEVELOPS TUESDAY
NIGHT WILL TAPER OFF AGAIN WEDNESDAY MORNING FOR ANOTHER MILD
SEPTEMBER DAY WEDNESDAY. A LITTLE MORE MID TO UPPER CLOUDS MAY
FILTER INTO NORTH CENTRAL WISCONSIN LATER WEDNESDAY AS A NORTHERN
PLAINS FRONTAL SYSTEM VERY SLOWLY APPROACHES THE REGION.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
MAIN FCST SYSTEM OF INTEREST TO BE THE MOVEMENT OF A SHORTWAVE
TROF FROM THE WEST COAST MID-WEEK...TO THE GREAT LAKES AT THE END
OF THE WEEK. WARM/INCREASINGLY MORE HUMID AIR MASS TO PUSH INTO WI
AHEAD OF THIS APPROACHING UPR TROF WHICH WL LEAD TO AN UNSETTLED
WEATHER PERIOD FROM WED NGT THRU FRI NGT. THE MEAN FLOW TURNS
ZONAL FOR EARLY NEXT WEEK WITH DRIER/COOLER AIR MASS SPREADING
OVER THE REGION.
PREVAILING SW WIND WL CONT INTO THE WRN GREAT LAKES WED NGT WITH
WAA AND A SHORTWAVE HEADED TOWARD NE WI. ENUF MOISTURE MAY BE
PRESENT TO BRING AT LEAST A SMALL CHC OF SHWRS/TSTMS TOWARD CNTRL
WI...ESPECIALLY AFTER MIDNGT. OTHERWISE...CLOUDS SHOULD CONT TO
INCREASE/THICKEN THRU THE NGT WITH MIN TEMPS MAINLY IN THE LWR TO
MID 60S. A STRONG AREA OF LOW PRES IS FCST TO MOVE FROM THE NRN
PLAINS NEWD INTO SW ONTARIO ON THU AND PULL A CDFNT EWD TOWARD THE
MN/WI BORDER BY 00Z FRI. THE STRONGER MID-LEVEL FORCING IS
ADVERTISED BY THE MODELS TO REMAIN NEAR THE SFC LOW...THEREBY
LEAVING THE CDFNT AS THE MAIN TRIGGER FOR PCPN DEVELOPMENT. SINCE
THE FRONT IS STILL WELL TO OUR WEST...IT MAY BE DIFFICULT FOR PCPN
TO PUSH TOO FAR EWD. WL CONT TO FOCUS HIGHER POPS OVER CNTRL WI...
BUT MAY TRIM VALUES A BIT. ANOTHER WARM DAY IS EXPECTED WITH MAX
TEMPS IN THE MID TO UPR 70S NORTH/LAKESHORE...AROUND 80 DEGS
SOUTH.
MODELS SEND THE CDFNT INTO ERN WI THU NGT (GFS A TAD FASTER)...
ACCOMPANIED BY SEVERAL SHORTWAVES MOVING NEWD THRU THE MEAN SW
FLWO ALOFT. PREVIOUS SHIFT ALREADY HAD LIKELY POPS ACROSS THE
ENTIRE FCST AREA WHICH STILL LOOKS VALID AT THIS TIME. IF THERE IS
A QUESTION...IT IS THE SPEED OF THE CDFNT AND WHETHER SHWR/TSTM
ACTIVITY WL BEGIN TO DIMINISH OVER CNTRL WI LATE THU NGT. MAY END
UP SPLITTING THE POP GRID AND SHOW A DIMINISHING TREND IN THE POPS
FOR CNTRL WI. MIN TEMPS TO RANGE FROM THE MID TO UPR 50S
N-CNTRL...LWR 60S E-CNTRL WI. FRI`S FCST IS A BIT TRICKY AS THE
MODELS INDICATE A SFC WAVE TO DEVELOP ON THE TAIL OF THE CDFNT AND
MOVE NE TOWARD THE MID-MS VALLEY. MEANWHILE...THE SHORTWAVE TROF
WL BE SWEEPING EWD ACROSS THE NRN PLAINS WITH VARIOUS SHORTWAVES
EMBEDDED WITHIN THE TROF. ANY BREAK IN THE PCPN CHCS APPEAR SHORT-
LIVED AS SHWRS/TSTMS CONVERGE ON WI...ESPECIALLY BY FRI AFTERNOON.
MAY NEED TO TWEAK POPS UP A BIT AS A RESULT. MAX TEMPS TO COOL A
LITTLE FROM PREVIOUS DAYS WITH READINGS IN THE MID TO UPR 60S
N-CNTRL...LWR TO MID 70S E-CNTRL WI.
THE SFC WAVE AND SHORTWAVE TROF CONVERGE ON THE GREAT LAKES FRI
NGT WHICH SHOULD BRING A GOOD CHC FOR ADDITIONAL SHWRS/TSTMS TO NE
WI. THE BACK EDGE OF ANY LINGERING SHWRS MAY AFFECT ERN WI INTO
SAT MORNING...OTHERWISE HI PRES IS FCST TO BUILD ACROSS THE
MIDWEST AND BRING INCREASING SUNSHINE TO THE REGION FOR A GOOD
PART OF SAT. MAX TEMPS SHOULD BE CLOSE TO NORMAL WITH READINGS IN
THE MID 60S TO AROUND 70S DEGS. THIS AREA OF HI PRES TO LIFT NE
INTO THE GREAT LAKES FOR THE LATTER HALF OF THE WEEKEND...THEREBY
BRINGING QUIET WEATHER CONDITIONS TO NE WI WITH TEMPS HOLDING
SLIGHTLY ABOVE NORMAL. A RETURN FLOW DEVELOPS OVER WI BY NEXT MON
WITH WINDS BECOMING S-SW. NO TRIGGER IS EVIDENT...THUS NO PCPN
ANTICIPATED THRU MON. TEMPS ON MON MAY ADD A COUPLE OF DEGS FROM
SUNDAY WITH MOST LOCATIONS IN THE UPR 60S TO LWR 70S.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 625 AM CDT TUE SEP 15 2015
ISOLATED SHOWERS AND STORMS WILL END THIS MORNING
OTHERWISE VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT. LLWS
CONDITIONS OVER THE WESTERN HALF OF THE STATE THIS MORNING WILL
GIVE WAY TO GUSTY SOUTH SURFACE WINDS. AS SURFACE WINDS DIMINISH
EARLY EVENING...LLWS CONDITIONS AGAIN TO DEVELOP. AN ISOLATED
SHOWER OR STORM IS POSSIBLE LATER TONIGHT...BUT TOO LOW OF A
PROBABILITY TO ADD TO THE TAFS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
928 AM PDT TUE SEP 15 2015
.SYNOPSIS...
A TROUGH ALONG THE WEST COAST WILL BRING MOISTURE FROM THE REMNANTS
OF FORMER HURRICANE LINDA INTO THE REGION...BRINGING PERIODS OF RAIN
ALONG AND WEST OF THE MOUNTAINS THROUGH WEDNESDAY MORNING. SHOWERS
WILL LIKELY DIMINISH ON WEDNESDAY. STRONG ONSHORE FLOW WILL CREATE
GUSTY WESTERLY WINDS ACROSS THE DESERTS THIS AFTERNOON THROUGH THIS
EVENING. WARMING WILL BEGIN THURSDAY AND CONTINUE INTO THE WEEKEND
AS HIGH PRESSURE BUILDS ALOFT AND THE MARINE LAYER SHRINKS BACK
TOWARD THE COAST.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
THERE WAS PLENTY OF SHOWER ACTIVITY THIS MORNING FOR ORANGE
COUNTY...THE NORTHWEST INLAND EMPIRE...THE SAN BERNARDINO COUNTY
MOUNTAINS AND THE HIGH DESERTS. ALTHOUGH THE RADAR RETURNS OVERALL
WERE NOT TOO IMPRESSIVE LOOKING...THEY ARE DROPPING A GOOD AMOUNT OF
RAINFALL THIS MORNING...ESPECIALLY IN ORANGE COUNTY...WHERE RAINFALL
TOTALS ARE WIDESPREAD 0.75 TO 1 INCH...AND EVEN SOME TOTALS NEAR 1.5
INCHES. SOME COASTAL MOUNTAIN SLOPES HAVE GOTTEN NEAR 2 INCHES. AS A
RESULT...SOME MINOR URBAN FLOODING HAS BEEN REPORTED IN SOME ORANGE
AND SAN BERNARDINO COUNTY LOCATIONS. THE 12Z MIRAMAR SOUNDING SHOWS
1.61 INCHES OF PRECIPITABLE WATER...WHICH IS VERY HIGH...WITH A
MOIST LAYER UP THROUGH 600 MB...OR 15000 FEET. ALSO EVIDENT ON THE
SOUNDING ARE TWO SIGNIFICANT CAPPING INVERSIONS...ONE AT AROUND 7000
FEET ASSOCIATED WITH THE MARINE LAYER...AND ANOTHER STRONGER CAP AT
15000 FEET. IT SEEMS LIKELY THAT...UNLESS THIS SECOND CAP IS ERODED
OR IF THERE IS STRONG ENOUGH HEATING TO OVERCOME THE CAP...THAT THE
SHOWERS WILL NOT BE ABLE TO BUILD INTO THUNDERSTORMS.
INFRARED SATELLITE SHOWS THE COLDER CLOUD TOPS ASSOCIATED WITH THE
BANDS OF RAIN MOVING THROUGH THE FORECAST AREA THIS MORNING...WITH
COLDER CLOUD TOPS STARTING TO SHOW UP OVER THE SAN DIEGO COUNTY
WATERS MOVING EAST INTO SAN DIEGO COUNTY. THE LATEST HRRR SHOWS THE
SHOWERS IN ORANGE COUNTY DISSIPATING OVER THE NEXT COUPLE
HOURS...WITH SHOWERS PICKING UP AND INCREASING IN COVERAGE IN SAN
DIEGO COUNTY...EASTERN INLAND EMPIRE...THE EASTERN SAN BERNARDINO
COUNTY MOUNTAINS AND THE RIVERSIDE COUNTY MOUNTAINS FOR THE LATE
MORNING AND AFTERNOON PERIODS. FORECAST MODELS ARE IN GOOD AGREEMENT
WITH RAIN DIMINISHING OVERNIGHT INTO WEDNESDAY MORNING...WITH RAIN
COMPLETELY OUT OF THE AREA BY LATE WEDNESDAY MORNING...AS THE LAST
OF THE REMNANT MOISTURE FROM FORMER HURRICANE LINDA MOVES OUT OF THE
REGION.
LATEST FORECAST RAINFALL TOTALS FOR THE REST OF THE EVENT INDICATE
AROUND A HALF TO THREE QUARTERS OF AN INCH IN THE COAST AND
VALLEYS...AND INCH TO NEAR 2 INCHES IN THE MOUNTAINS...MAINLY ALONG
THE COASTAL SLOPES...A TENTH TO A QUARTER INCH IN THE HIGH
DESERTS...AND A TRACE TO A FEW HUNDREDTHS IN THE LOWER DESERTS.
WITH THE HIGH MOISTURE CONTENT BEING BROUGHT IN...THE DEW POINTS ARE
IN THE UPPERS 60S TO LOW 70S IN THE COAST AND VALLEY AREAS THIS
MORNING...MAKING FOR UNCOMFORTABLY HUMID CONDITIONS. AIR
TEMPERATURES SHOULD COOL A LITTLE BIT TODAY AND WEDNESDAY
HOWEVER...WITH THE LOWER HEIGHTS ALOFT AND CLOUDY CONDITIONS.
FINALLY...WITH THE STRONGER ONSHORE FLOW...SOME GUSTY CONDITIONS ARE
LIKELY THIS AFTERNOON AND THIS EVENING THROUGH AND BELOW THE
MOUNTAIN PASSES AND CANYONS...ALONG THE DESERT SLOPES...AND INTO
ADJACENT DESERT AREAS...WITH GUSTS TO 45 MPH POSSIBLE.
THURSDAY THROUGH SUNDAY...THE TROUGH TO THE NORTH MOVES FARTHER
INLAND AND WEAKENS...WITH RIDGING TO THE SOUTHEAST NUDGING INTO THE
REGION. THIS WILL BRING A WARMING TREND...WITH DAY-TIME HIGHS
REACHING SEVERAL DEGREES ABOVE NORMAL BY SUNDAY. EXPECT A SHALLOWER
MARINE LAYER AS WELL...WITH NIGHT AND MORNING STRATUS MAINLY ALONG
THE COAST.
FOR THIS WEEKEND...THE GFS AND ECMWF SHOW A WEAK UPPER LOW SPLITTING
OUT FROM THE JET STREAM AND THEN MOVING INTO A POSITION SOUTHWEST OF
SAN DIEGO FOR EARLY NEXT WEEK. THIS MAY ALLOW FOR TROPICAL MOISTURE
TO GET BROUGHT UP FROM THE SOUTH LATE NEXT MONDAY THROUGH MID-WEEK
FOR POSSIBLY SOME AFTERNOON MOUNTAIN AND DESERT THUNDERSTORMS.
&&
.AVIATION...
151600Z...COASTS/VALLEYS/MOUNTAINS...BAND OF MODERATE TO HEAVY RAIN
WILL MOVE ACROSS SOUTHERN CALIFORNIA THROUGH 22Z WITH BASES 005-010
AND 1-2SM VIS IN THE HEAVIEST RAIN. MERGING LAYERS TO 10000 FEET.
THE RAIN WILL TRANSITION TO SCATTERED SHOWERS BEHIND THE MAIN RAIN
BAND THAT WILL PASS THROUGH ORANGE COUNTY THIS MORNING AND THEN PASS
THROUGH THE INLAND EMPIRE AND SAN DIEGO COUNTY THIS AFTERNOON. CLOUD
BASES WILL LIFT TO BKN-OVC020-030 BEHIND THE MAIN RAIN BAND.
SHOWERS TAPERING OFF THIS EVENING...LINGERING LONGEST OVER THE
COASTAL SLOPES OF THE MOUNTAINS WHICH WILL BE OBSCURED IN
CLOUDS/FOG/SHRA THROUGH 14Z WEDNESDAY.
DESERTS...GUSTY WESTERLY WINDS OF 35-45 MPH WITH HIGHER GUSTS MAINLY
IN FAVORED LEE AREAS OF MOUNTAIN GAPS AND INTO ADJACENT DESERTS LATE
AFTERNOON THROUGH EVENING. ISOLATED SHOWERS TODAY MOST LIKELY IN THE
HIGH DESERT WITH CLOUDS AOA 8000 FEET MSL. MOSTLY CLEAR AFTER 02Z.
&&
.MARINE...
900 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SATURDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE...MOEDE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1207 PM MDT TUE SEP 15 2015
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 410 AM MDT TUE SEP 15 2015
FORECAST PROBLEMS WILL BE CHANCES OF PRECIPITATION...CONTINUED FIRE
WEATHER ISSUES INTO WEDNESDAY...AND HIGH TEMPERATURES. SATELLITE IS
SHOWING AN AMPLIFIED AND RETROGRESSIVE FLOW FROM THE PACIFIC TO
ALONG THE WEST COAST OF NORTH AMERICA. WESTERN TROUGH HAS BEGUN TO
DEVELOP WHICH NOW LEAVES THE AREA IN SOUTHWEST FLOW ALOFT. A RATHER
STRONG SHORTWAVE OVER THE DESERT SOUTHWEST IS MOVING TOWARD THE AREA
WITH RATHER MOIST MID LEVELS AHEAD OF IT.
AT JET LEVEL...THE NAM...CANADIAN...GFS AND ECMWF WERE DOING THE
BEST. AT MID LEVELS...THE UKMET/CANADIAN WERE DOING A LITTLE BETTER
THAN THE GFS/ECMWF. MODELS WERE HAVING THEIR PROBLEMS AT THE
SURFACE. THE RAP AND NAM WERE DOING THE BEST. THE NAM/CANADIAN/SREF
WERE DOING A LITTLE BETTER THAN THE GFS ON THE LOW LEVEL THERMAL
FIELD.
TODAY/TONIGHT...REFER TO THE FIRE WEATHER SECTION BELOW FOR
DISCUSSION ON FIRE WEATHER.
STILL A TRICKY/COMPLICATED THUNDERSTORM FORECAST WITH A LOT OF
UNCERTAINTY. LEFT FRONT QUADRANT OF THE SOUTHERN JET AFFECTS THE
SOUTHERN THIRD OF THE AREA LATE THIS AFTERNOON INTO EARLY THIS
EVENING BEFORE MOVING OFF. PROBLEM TO OVERCOME IS APPARENT LACK OF
LOW LEVEL MOISTURE AND INSTABILITY. THE TREND IN THE MODELS FOR THE
LAST THREE DAYS HAS BEEN TO PULL THE SURFACE TROUGH AND HIGHER
DEWPOINTS FURTHER EAST. CONSEQUENTLY THE INSTABILITY AXIS AND WHERE
THUNDERSTORMS INITIATE ARE ALSO FURTHER WEST AS WELL.
AS STATED ABOVE A DECENT SLUG OF MID LEVEL MOISTURE IS APPROACHING
FROM THE SOUTHWEST. SO THERE APPEARS TO BE BETTER MOISTURE THROUGH A
GREATER THAN INDICATED THE LAST FEW DAYS. SATELLITE/PV ANALYSIS
SHOULD A RATHER STRONG SHORTWAVE TROUGH IS MOVING FROM THE
SOUTHWEST. HOWEVER ARE TENDING WEAKEN THIS SOME WHICH DOES NOT SEEM
RIGHT. ALSO AFTER 00Z MODELS CONTINUE TO SHOW A RATHER STRONG LOW
LEVEL JET OVER THE EASTERN THIRD TO HALF OF THE FORECAST AREA.
CONVECTIVE ALLOWING MODELS ARE SHOWING MORE ROBUST CONVECTION
THAN PREVIOUSLY SHOWN WITH THE POSSIBILITY OF 2 OR 3 AREAS/TIME
PERIODS OF INITIATION. SO EXPANDED POPS FURTHER WEST AND INCREASED
POPS TO LOW CHANCE IN THE FAR SOUTH THIS AFTERNOON AND EARLY EVENING
DUE TO THE JET AND OVER THE EASTERN FORECAST AREA DUE TO THE LOW
LEVEL JET AND STRONG SHORTWAVE MOVING THROUGH.
WILL KEEP THINGS HOT AGAIN TODAY ALTHOUGH THE DOWNSLOPE COMPONENT TO
THE WINDS MAY NOT LAST AS LONG AS PREVIOUSLY INDICATED. ALSO CLOUD
COVER MOVING IN FROM THE SOUTHWEST AND WITH THUNDERSTORM INITIATION
COULD HOLD BACK THE WARMING. AT THIS TIME IT LOOKS LIKE MID TO UPPER
90S FOR THE AREA.
WEDNESDAY/WEDNESDAY NIGHT...REFER TO THE FIRE WEATHER SECTION BELOW
FOR DISCUSSION ON FIRE WEATHER.
MODELS ROTATE LEFT FRONT QUADRANT OF THE JET ACROSS THE AREA THROUGH
THE DAY. THE MODELS DO NOT MOVE THIS VERY FAR OFF WITH SOME KIND OF
JET LIFT THROUGH THE NIGHT ESPECIALLY OVER THE NORTHERN AND WESTERN
PORTIONS. HOWEVER THE SOUNDINGS SHOW AN EXTREMELY DEEP DRY AIR MASS.
SOME OF THE NWP IS SHOWING LOW POPS BUT THAT SEEMS OVERDONE.
CONVECTIVE ALLOWING MODELS ARE DRY. SO THIS LIFT LOOKS TO JUST
PRODUCE CLOUDS AND HAVE THE FORECAST DRY THROUGH THE PERIOD.
MODELS ARE SAYING IT SHOULD BE SLIGHTLY COOLER. MODELS HAVE HAD A
TENDENCY TO BE TOO COOL. HOWEVER THE WIND FIELD IS LIGHTER AND NOT
AS HELPFUL IN GETTING THE TEMPERATURES WARMER. SO TEMPERATURES AT
THIS WILL BE NEAR OR SLIGHTLY COOLER THAN WHAT WAS IN THERE FOR
TODAY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OR OVER THE
NORTHERN AND WESTERN SECTIONS THROUGH THE PERIOD. AGAIN THE
SOUNDINGS ARE INITIALLY SHOWING A DEEP DRY LAYER BUT NOT AS MUCH AS
THE PREVIOUS DAY. AT THIS TIME DOES LOOK LIKE THE STRONGER LIFT DOES
NOT ARRIVE UNTIL THE NIGHT PERIOD AND ESPECIALLY IN THE LAST HALF OF
THE NIGHT. AGAIN AM NOT CONFIDENT ABOUT THIS DUE TO A LACK OF
SIGNIFICANT MOISTURE BUT THE LIFT IS PRETTY STRONG. AT THIS IT LOOKS
LIKE THE NORTHEAST HALF WILL HAVE THE BEST CHANCE FOR PRECIPITATION.
IT DOES LOOK COOLER BUT THE MODELS DISAGREE ON HOW MUCH COOLER. WILL
DEFINITELY HAVE THE MOST UNFAVORABLE WIND FIELD OUT OF THE LAST 3
DAYS TO HELP THE WARMING. GOING BY RECENT TRENDS/BIASES...I DID MAKE
THE MAXES COOLER BUT TRENDED TOWARD THE WARMER GUIDANCE.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 202 AM MDT TUE SEP 15 2015
THE LONG TERM STARTS OFF WITH AN H5 RIDGE THAT WILL SETTLE SOUTHWARD
INTO SOUTHWESTERN TEXAS. THE FLOW PATTERN ALOFT WILL SHIFT FROM
SOUTHWEST THEN TO WEST AND EVENTUALLY TO WEST NORTHWEST OVER THE
EXTENDED PERIOD. AS THIS HAPPENS... SEVERAL H7 TROUGHS WILL MOVE OUT
OF THE CENTRAL ROCKIES AND THEN MOVE EASTWARD ACROSS THE CWA.
CONFIDENCE IN THE GUIDANCE IS RELATIVELY LOW AT THIS POINT WITH THE
GFS AND ECMWF BEING IN STRONG DISAGREEMENT WITH REGARDS TO THE
AMOUNT OF MOISTURE THAT WILL BE AVAILABLE WHEN THIS HAPPENS.
CURRENTLY THE ECMWF IS THE WETTER OF THE TWO HOWEVER THIS IS
OPPOSITE OF THE SCENARIO IN EARLIER MODEL RUNS. I WENT WITH AROUND
20 PERCENT POPS ON SATURDAY IN THE SOUTHERN PORTIONS OF THE CWA AS
ONE OF THESE H7 TROUGHS MOVE ACROSS THE REGION AND THEN WITH 30
PERCENT POPS ON SUNDAY AFTERNOON AS A STRONGER H5 TROUGH MOVES
ACROSS THE AREA. IF THE ECMWF SOLUTION PROVES TRUE THEN POP CHANCES
WOULD BE IN THE 40 TO 50 PERCENT RANGE BUT WE WILL NEED TO MONITOR
THE FUTURE MODEL RUNS TO SEE IF THERE IS ANY CONSISTENCY. THE GFS
SHOWS A MOSTLY DRY FORECAST FOR THIS SAME TIME FRAME.
TEMPERATURES DURING THE EXTENDED PERIOD WILL BEGIN NEAR NORMAL WITH
HIGHS IN THE 70S AND LOWS IN THE 40S TO LOW 50S ON FRIDAY AND
SATURDAY... THEN INCREASING ON SUNDAY AND MONDAY WITH HIGHS IN THE
80S AND LOWS IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1134 AM MDT TUE SEP 15 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT GLD AND
MCK. ISOLATED AFTERNOON TO EVENING THUNDERSTORMS MAY DEVELOP
BETWEEN 21Z-02Z ALONG AND EAST OF A SURFACE TROUGH IMMEDIATELY TO
THE EAST OF THE EASTERN COLORADO BORDER. THUNDERSTORMS ARE NOT
EXPECTED TO BE A PREVAILING CONDITION AT EITHER SITE AND HAVE BEEN
EXCLUDED FROM THE TAFS. GUSTY SOUTHWEST TO SOUTH WINDS HAVE
DEVELOPED THIS AFTERNOON AS A RESULT OF THE SURFACE TROUGH
DEEPENING OVER THE CENTRAL HIGH PLAINS. GUSTY WINDS ARE EXPECTED
TO REMAIN IN PLACE UNTIL AFTER 08Z WHEN WINDS BEGIN TO RELAX DUE
TO THE OVERNIGHT INVERSION AND THE DECREASING PRESSURE GRADIENT
EVEN THOUGH THE SURFACE TROUGH AXIS MOVES VERY LITTLE OVER THE
NEXT 24-36 HOURS. WITH THE OVERNIGHT INVERSION SETTING UP...THERE
IS A POTENTIAL FOR LOW LEVEL WIND SHEAR DEVELOPING BETWEEN 06Z-10Z
AT BOTH GLD AND MCK. MODEL SOLUTIONS ARE NOT CURRENTLY IDENTIFYING
ANY LLWS...SO JUST MENTIONING THE POSSIBILITY OF IT
OCCURRING...AND NOT INCLUDING IT IN THE FORECAST AT THIS TIME.
&&
.FIRE WEATHER...
ISSUED AT 410 AM MDT TUE SEP 15 2015
FOR TODAY...IN SHORT DESPITE A LITTLE MORE UNCERTAINTY WILL BE
KEEPING THE CURRENT RED FLAG WARNING. AM A LITTLE CONCERNED WITH THE
SLIGHT WESTWARD SHIFT OF HIGHER DEWPOINTS. SAYING THAT HOWEVER IF
MORE MIXING OCCURS THAN I THINK DEWPOINTS COULD BE SHARPLY LOWER
THAN WHAT I HAVE THEM. THE WINDS WILL DEFINITELY REACH THE NEEDED
CRITERIA. ALSO WILL BE HAVING HIGH BASED THUNDERSTORMS WITH GUSTY
AND ERRATIC WINDS AND NOT A LOT OF RAINFALL.
FOR WEDNESDAY...AT THIS TIME A MARGINAL FIRE WEATHER DAY IS
EXPECTED. WINDS WILL BE LIGHT AND VARIABLE UNTIL MID AFTERNOON DUE
TO ONE SURFACE TROUGH MOVING OFF TO THE EAST AND THE NEXT ONE
FORMING TO THE WEST. MODELS DO HANDLE THIS SCENARIO WELL AND USUALLY
OVERPREDICT WIND SPEEDS. MODELS DO SHOW WINDS INCREASING TO 10 TO 20
MPH WITH GUSTS TO NEAR 25 MPH AROUND MID AFTERNOON. RELATIVE
HUMIDITIES LOOK TO BE A LITTLE HIGHER AND CLOSER TO 20 PERCENT
RATHER THAN 15 PERCENT. THINKING IS THAT WE WILL NOT BE ABLE TO MEET
THE 3 HOUR CRITERIA. WILL BRIEF THE DAY SHIFT ON THIS AND MENTION
THE POSSIBILITY IN THE HWO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR
KSZ001-013-027-041.
CO...RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ252>254.
NE...RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR NEZ079.
&&
$$
SHORT TERM...BULLER
LONG TERM...TL
AVIATION...LOCKHART
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
349 PM EDT TUE SEP 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 321 PM EDT TUE SEP 15 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WRN TROF/ERN RDG
PATTERN...WITH DEEP SW FLOW ARND SFC HI PRES IN THE MID ATLANTIC
STATES ADVECTING UNSEASONABLY WARM AIR INTO THE UPR GREAT LKS. 12Z
H85 TEMPS WERE 18C AT APX/GRB AND 19C AT MPX. DESPITE STEEP MID LVL
LAPSE RATES AND SOME MODEST H85 THETA E ADVECTION THAT SUPPORTED
SOME SCT SHOWERS/TS OVER NE WI EARLIER THIS MRNG...ABSENCE OF
DYNAMIC FORCING WITH LLVL ACYC FLOW AND VERY SHARP CAPPING/DRY MID
LYR DEPICTED ON THE 12Z MPX RAOB THAT ARE OVERSPREADING THE AREA
HAVE MAINTAINED DRY WX OVER UPR MI. SFC TEMPS HAVE RISEN INTO THE
80S AT MANY PLACES AWAY FM LK MI MODERATION DESPITE SOME PATCHY HI
CLDS.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON TEMPS/WINDS AND SLIM
PCPN CHCS.
TNGT...STRONG SW FLOW...WITH SHARPENING PRES GRADIENT INCRSG H925
WINDS UP TO 40-45 KTS...IS FCST TO DOMINATE THE AREA. NOCTURNAL
COOLING/INVRN WL LIMIT THE SFC WIND GUSTS. ALTHOUGH THESE STRONG
WINDS WL INITIALLY TAP AN AREA OF DRIER LLVL AIR NOW OVER THE LOWER
GREAT LKS...MODELS SHOW THE H85 FLOW VEERING A BIT OVERNGT AND
ADVECTING HIER H85-7 THETA E INTO MAINLY THE NW HALF OF UPR MI
OVERNGT. A NUMBER OF THE MODELS GENERATE SOME PCPN IN THIS AREA
LATE. BUT CONSIDERING THE STRONG CAPPING DEPICTED ON THE 12Z MPX
RAOB...THE ABSENCE OF ANY OTHER SGNFT DYNAMIC FORCING/HGT FALLS AND
RELATIVELY DRY SFC-H7 LYR SHOWN ON THE 12Z NAM FCST SDNGS...OPTED TO
FOLLOW THE DRIER GUIDANCE AND MAINTAIN GOING DRY FCST. THE
COMBINATION OF STRONG WINDS AND INCRSG MID/HI CLDS ACCOMPANYING THE
MSTR RETURN WL RESULT IN A VERY WARM OVERNGT...ESPECIALLY IN THE
DOWNSLOPE AREAS NEAR LK SUP OVER THE NW HALF...WHERE FCST WL TEND
TOWARD THE HI END OF GUIDANCE.
WED...MAINTAINED SOME SCHC POPS OVER THE FAR NW CWA...WHERE SHRTWV
FCST TO LIFT NE THRU FAR NW ONTARIO MAY BE CLOSE ENUF TO AXIS OF
HIER H85-7 THETA E TO GENERATE SOME SHOWERS/TS. THE REST OF THE CWA
WL REMAIN DRY. DAYTIME HEATING/MIXING WL CAUSE THE STRONG LLVL WINDS
TO MIX TO THE SFC...WITH GUSTS AS HI AS 30 TO 35 MPH AT THE MORE
EXPOSED LOCATIONS. WITH H85 TEMPS FCST AS HI AS 20-22C...EXPECT MAX
TEMPS TO CLIMB WELL INTO THE 80S AWAY FM THE COOLING INFLUENCE OF LK
MI. TENDED TOWARD THE HI END OF GUIDANCE FOR MAX TEMPS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE SEP 15 2015
A COLD FRONT THAT WILL MOVE ACROSS THE AREA LATE THURSDAY AFTERNOON
AND THURSDAY NIGHT WILL START A BRIEF PERIOD OF NORMAL TO BELOW
NORMAL TEMPERATURES...BEFORE TRENDING BACK ABOVE NORMAL FOR EARLY
NEXT WEEK. AHEAD OF THE COLD FRONT...MODELS ARE CONTINUING TO PAINT
ISOLATED TO SCATTERED SHOWERS OVER WESTERN LAKE SUPERIOR AND
PORTIONS OF THE WESTERN U.P. WEDNESDAY NIGHT INTO THURSDAY MORNING
UNDER THE SOUTHWESTERLY FLOW WARM AIR ADVECTION...STEEP 750-400MB
LAPSE RATES AND OCCASIONAL EMBEDDED SHORTWAVES. MOISTURE LOOKS TO
BE THE MAIN LIMIT AT THIS POINT...BUT WILL CONTINUE TO SHOW SLIGHT
TO LOW CHANCE POPS IN THAT AREA AS ANY LITTLE BIT OF MOISTURE WILL
BE ABLE TO PRODUCE SOME SHOWERS. THE DRY LOW LEVEL AIR WILL LIKELY
LIMIT THE WEAKER SHOWERS FROM REACHING THE GROUND. CLOUDS AHEAD OF
THE COLD FRONT WILL LEAD TO SLIGHTLY COOLER HIGHS ON THURSDAY...BUT
STILL EXPECT THEM TO BE ABOVE NORMAL AND IN THE 70S WITH A FEW
LOWER 80S IN THE FAVORED DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
FOR THE COLD FRONT PASSAGE THURSDAY AFTERNOON INTO THURSDAY
NIGHT...NOT A WHOLE LOT HAS CHANGED OVER THE LAST 24 HOURS AND THE
GOING FORECAST HAS A GOOD HANDLE ON THE TIMING OF THE POPS AS THE
FRONT MOVES THROUGH. ONLY MADE MINOR TWEAKS TO THE TIMING OF THE
POPS AND EXPECT CAPPING OUT AHEAD OF THE FRONT WILL LIKELY
CONFINE MUCH OF THE SHOWERS/THUNDERSTORMS TO RIGHT ALONG THE FRONT.
AS HAS BEEN MENTIONED IN PREVIOUS DISCUSSIONS...THERE IS THE
POTENTIAL FOR MARGINALLY SEVERE STORMS OVER THE WESTERN CWA AND FEEL
THE MARGINAL RISK IN THE DAY 3 SPC OUTLOOK IS FAIRLY REASONABLE.
THE FRONT WILL QUICKLY DEPART EARLY FRIDAY MORNING AND HAVE TRENDED
THE DEPARTURE OF THE PRECIPITATION A LITTLE FASTER THAN THE
PREVIOUS FORECAST. SHOULD SEE PARTLY TO MOSTLY CLEAR SKIES
IMMEDIATELY BEHIND THE FRONT AS A SURFACE RIDGE MOVES IN AHEAD OF
THE NEXT SHORTWAVE ARRIVING FROM THE SOUTHWEST (AND INCREASING
MID-HIGH CLOUDS IN THE AFTERNOON). HIGHS ON FRIDAY WILL RETURN TO
MORE NORMAL VALUES FOR MID SEPTEMBER (60S).
THE COLD FRONT WILL STALL OVER LOWER MICHIGAN LATE FRIDAY AFTERNOON
INTO FRIDAY EVENING AS A ANOTHER SHORTWAVE MOVES EAST OUT OF THE
NORTHERN/CENTRAL PLAINS. A SURFACE LOW WILL DEVELOP ALONG THE FRONT
AS IT MOVES TOWARDS THE GREAT LAKES REGION BEFORE LIFTING ACROSS
NORTHERN LAKE/LOWER MICHIGAN LATE FRIDAY NIGHT INTO SATURDAY
MORNING. THE SHORTWAVE WILL COMBINE WITH THE STALLED FRONT TO FOCUS
MODERATE TO OCCASIONALLY HEAVY RAIN TO THE SOUTHEAST OF THE
AREA...BUT STILL EXPECT AT LEAST THE SOUTHEAST HALF TO 2/3RDS OF THE
CWA TO SEE A TENTH OF AN INCH OF RAIN ON THE NORTHWEST SIDE OF THE
PRECIPITATION SHIELD. CONTINUED TO TREND POPS UP IN THAT AREA AND
HAVE VALUES NEAR LIKELIES ALONG THE LAKE MICHIGAN SHORELINE FOR
LATE FRIDAY NIGHT. THE SHORTWAVE WILL DEPART AND HIGH PRESSURE WILL
QUICKLY BUILD INTO THE AREA ON SATURDAY...RAPIDLY ENDING THE RAIN
FROM WEST TO EAST ON SATURDAY MORNING. A BRIEF SHOT OF COLDER AIR
WILL BE IN PLACE ON SATURDAY AND WITH THE BREEZY NORTHERLY
WINDS...THE LOWER 60S HIGHS WILL FEEL MUCH COOLER THAN THE LAST
COUPLE OF DAYS. FORTUNATELY...INCREASING SUNSHINE DURING THE
AFTERNOON SHOULD HELP OFFSET THE COOLER TEMPERATURES. THE HIGH THAT
WILL BUILD IN ON SATURDAY WILL REMAIN IN PLACE INTO MONDAY NIGHT
AND LEAD TO DRY CONDITIONS. THERE ARE HINTS OF A WEAK FRONT MOVING
ACROSS THE AREA ON TUESDAY...BUT WITH MUCH OF THE FORCING STAYING
WELL TO THE NORTH OF THE AREA...WILL GO WITH SILENT 20 POPS FOR
THE WESTERN CWA FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 148 PM EDT TUE SEP 15 2015
A STRENGTHENING SSW WIND WL DOMINATE THIS FCST PERIOD BTWN HI PRES
OVER THE MID ATLANTIC AND LO PRES IN THE HI PLAINS. THE SFC WIND
GUSTS WL BE STRONGEST AT THE MORE EXPOSED IWD AND SAW LOCATIONS.
ALTHOUGH THE STRONGEST WINDS WL OCCUR DURING THE DAYLIGHT HRS...THE
PRES GRADIENT WL BE STRONG ENUF TO CAUSE GUSTY WINDS AT IWD THRU THE
NGT. AT THE MORE SHELTERED CMX SITE...LLWS WL DEVELOP TNGT AS A
NOCTURNAL INVRN DEVELOPS BLO THE AXIS OF STRONGEST WINDS. THE FCST
FOR SAW IS A BIT MORE TRICKY AS THERE MAY BE PERIODS OF GUSTY WINDS
AS WELL TNGT. BUT MAINTAINED FCST LLWS THERE TNGT IN CASE THE NEAR
SFC STABILITY BECOMES SUFFICIENT TO LIMIT MIXING. ALTHOUGH THERE WL
BE MORE MID/HI CLDS LATER TNGT AND WED MRNG ESPECIALLY OVER THE NW
HALF OF UPR MI...LINGERING LLVL DRY AIR WL BRING VFR CONDITIONS THE
ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EDT TUE SEP 15 2015
WINDY CONDITIONS ARE SHAPING UP FOR MUCH OF LAKE SUPERIOR INTO WED
AS THE UPPER LAKES WILL BE SITUATED BTWN A LO PRES TROF TO THE NW
AND HI PRES OVER THE MID ATLANTIC STATES. EXPECT S WINDS TO INCREASE
TO AS HI AS 25-30 KTS TONIGHT INTO WED. NOT OUT OF THE QUESTION THAT
THE HIGHEST OBS PLATFORMS WILL SEE GALE FORCE GUSTS...ESPECIALLY
OVER THE E HALF. WINDS WILL DIMINISH A BIT WED AFTERNOON/THU...
ESPECIALLY OVER THE W HALF OF THE LAKE. A COLD FRONT WILL PASS THU
NIGHT/FRI MORNING...RESULTING IN A WIND SHIFT TO THE N AROUND 20 KT
FRI NIGHT INTO SAT. LIGHT WINDS WILL THEN DOMINATE ON SAT INTO SUN
AS TRAILING HI PRES MOVES BY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
343 PM EDT TUE SEP 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 321 PM EDT TUE SEP 15 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WRN TROF/ERN RDG
PATTERN...WITH DEEP SW FLOW ARND SFC HI PRES IN THE MID ATLANTIC
STATES ADVECTING UNSEASONABLY WARM AIR INTO THE UPR GREAT LKS. 12Z
H85 TEMPS WERE 18C AT APX/GRB AND 19C AT MPX. DESPITE STEEP MID LVL
LAPSE RATES AND SOME MODEST H85 THETA E ADVECTION THAT SUPPORTED
SOME SCT SHOWERS/TS OVER NE WI EARLIER THIS MRNG...ABSENCE OF
DYNAMIC FORCING WITH LLVL ACYC FLOW AND VERY SHARP CAPPING/DRY MID
LYR DEPICTED ON THE 12Z MPX RAOB THAT ARE OVERSPREADING THE AREA
HAVE MAINTAINED DRY WX OVER UPR MI. SFC TEMPS HAVE RISEN INTO THE
80S AT MANY PLACES AWAY FM LK MI MODERATION DESPITE SOME PATCHY HI
CLDS.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON TEMPS/WINDS AND SLIM
PCPN CHCS.
TNGT...STRONG SW FLOW...WITH SHARPENING PRES GRADIENT INCRSG H925
WINDS UP TO 40-45 KTS...IS FCST TO DOMINATE THE AREA. NOCTURNAL
COOLING/INVRN WL LIMIT THE SFC WIND GUSTS. ALTHOUGH THESE STRONG
WINDS WL INITIALLY TAP AN AREA OF DRIER LLVL AIR NOW OVER THE LOWER
GREAT LKS...MODELS SHOW THE H85 FLOW VEERING A BIT OVERNGT AND
ADVECTING HIER H85-7 THETA E INTO MAINLY THE NW HALF OF UPR MI
OVERNGT. A NUMBER OF THE MODELS GENERATE SOME PCPN IN THIS AREA
LATE. BUT CONSIDERING THE STRONG CAPPING DEPICTED ON THE 12Z MPX
RAOB...THE ABSENCE OF ANY OTHER SGNFT DYNAMIC FORCING/HGT FALLS AND
RELATIVELY DRY SFC-H7 LYR SHOWN ON THE 12Z NAM FCST SDNGS...OPTED TO
FOLLOW THE DRIER GUIDANCE AND MAINTAIN GOING DRY FCST. THE
COMBINATION OF STRONG WINDS AND INCRSG MID/HI CLDS ACCOMPANYING THE
MSTR RETURN WL RESULT IN A VERY WARM OVERNGT...ESPECIALLY IN THE
DOWNSLOPE AREAS NEAR LK SUP OVER THE NW HALF...WHERE FCST WL TEND
TOWARD THE HI END OF GUIDANCE.
WED...MAINTAINED SOME SCHC POPS OVER THE FAR NW CWA...WHERE SHRTWV
FCST TO LIFT NE THRU FAR NW ONTARIO MAY BE CLOSE ENUF TO AXIS OF
HIER H85-7 THETA E TO GENERATE SOME SHOWERS/TS. THE REST OF THE CWA
WL REMAIN DRY. DAYTIME HEATING/MIXING WL CAUSE THE STRONG LLVL WINDS
TO MIX TO THE SFC...WITH GUSTS AS HI AS 30 TO 35 MPH AT THE MORE
EXPOSED LOCATIONS. WITH H85 TEMPS FCST AS HI AS 20-22C...EXPECT MAX
TEMPS TO CLIMB WELL INTO THE 80S AWAY FM THE COOLING INFLUENCE OF LK
MI. TENDED TOWARD THE HI END OF GUIDANCE FOR MAX TEMPS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE SEP 15 2015
A COLD FRONT THAT WILL MOVE ACROSS THE AREA LATE THURSDAY AFTERNOON
AND THURSDAY NIGHT WILL START A BRIEF PERIOD OF NORMAL TO BELOW
NORMAL TEMPERATURES...BEFORE TRENDING BACK ABOVE NORMAL FOR EARLY
NEXT WEEK. AHEAD OF THE COLD FRONT...MODELS ARE CONTINUING TO PAINT
ISOLATED TO SCATTERED SHOWERS OVER WESTERN LAKE SUPERIOR AND
PORTIONS OF THE WESTERN U.P. WEDNESDAY NIGHT INTO THURSDAY MORNING
UNDER THE SOUTHWESTERLY FLOW WARM AIR ADVECTION...STEEP 750-400MB
LAPSE RATES AND OCCASIONAL EMBEDDED SHORTWAVES. MOISTURE LOOKS TO
BE THE MAIN LIMIT AT THIS POINT...BUT WILL CONTINUE TO SHOW SLIGHT
TO LOW CHANCE POPS IN THAT AREA AS ANY LITTLE BIT OF MOISTURE WILL
BE ABLE TO PRODUCE SOME SHOWERS. THE DRY LOW LEVEL AIR WILL LIKELY
LIMIT THE WEAKER SHOWERS FROM REACHING THE GROUND. CLOUDS AHEAD OF
THE COLD FRONT WILL LEAD TO SLIGHTLY COOLER HIGHS ON THURSDAY...BUT
STILL EXPECT THEM TO BE ABOVE NORMAL AND IN THE 70S WITH A FEW
LOWER 80S IN THE FAVORED DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
FOR THE COLD FRONT PASSAGE THURSDAY AFTERNOON INTO THURSDAY
NIGHT...NOT A WHOLE LOT HAS CHANGED OVER THE LAST 24 HOURS AND THE
GOING FORECAST HAS A GOOD HANDLE ON THE TIMING OF THE POPS AS THE
FRONT MOVES THROUGH. ONLY MADE MINOR TWEAKS TO THE TIMING OF THE
POPS AND EXPECT CAPPING OUT AHEAD OF THE FRONT WILL LIKELY
CONFINE MUCH OF THE SHOWERS/THUNDERSTORMS TO RIGHT ALONG THE FRONT.
AS HAS BEEN MENTIONED IN PREVIOUS DISCUSSIONS...THERE IS THE
POTENTIAL FOR MARGINALLY SEVERE STORMS OVER THE WESTERN CWA AND FEEL
THE MARGINAL RISK IN THE DAY 3 SPC OUTLOOK IS FAIRLY REASONABLE.
THE FRONT WILL QUICKLY DEPART EARLY FRIDAY MORNING AND HAVE TRENDED
THE DEPARTURE OF THE PRECIPITATION A LITTLE FASTER THAN THE
PREVIOUS FORECAST. SHOULD SEE PARTLY TO MOSTLY CLEAR SKIES
IMMEDIATELY BEHIND THE FRONT AS A SURFACE RIDGE MOVES IN AHEAD OF
THE NEXT SHORTWAVE ARRIVING FROM THE SOUTHWEST (AND INCREASING
MID-HIGH CLOUDS IN THE AFTERNOON). HIGHS ON FRIDAY WILL RETURN TO
MORE NORMAL VALUES FOR MID SEPTEMBER (60S).
THE COLD FRONT WILL STALL OVER LOWER MICHIGAN LATE FRIDAY AFTERNOON
INTO FRIDAY EVENING AS A ANOTHER SHORTWAVE MOVES EAST OUT OF THE
NORTHERN/CENTRAL PLAINS. A SURFACE LOW WILL DEVELOP ALONG THE FRONT
AS IT MOVES TOWARDS THE GREAT LAKES REGION BEFORE LIFTING ACROSS
NORTHERN LAKE/LOWER MICHIGAN LATE FRIDAY NIGHT INTO SATURDAY
MORNING. THE SHORTWAVE WILL COMBINE WITH THE STALLED FRONT TO FOCUS
MODERATE TO OCCASIONALLY HEAVY RAIN TO THE SOUTHEAST OF THE
AREA...BUT STILL EXPECT AT LEAST THE SOUTHEAST HALF TO 2/3RDS OF THE
CWA TO SEE A TENTH OF AN INCH OF RAIN ON THE NORTHWEST SIDE OF THE
PRECIPITATION SHIELD. CONTINUED TO TREND POPS UP IN THAT AREA AND
HAVE VALUES NEAR LIKELIES ALONG THE LAKE MICHIGAN SHORELINE FOR
LATE FRIDAY NIGHT. THE SHORTWAVE WILL DEPART AND HIGH PRESSURE WILL
QUICKLY BUILD INTO THE AREA ON SATURDAY...RAPIDLY ENDING THE RAIN
FROM WEST TO EAST ON SATURDAY MORNING. A BRIEF SHOT OF COLDER AIR
WILL BE IN PLACE ON SATURDAY AND WITH THE BREEZY NORTHERLY
WINDS...THE LOWER 60S HIGHS WILL FEEL MUCH COOLER THAN THE LAST
COUPLE OF DAYS. FORTUNATELY...INCREASING SUNSHINE DURING THE
AFTERNOON SHOULD HELP OFFSET THE COOLER TEMPERATURES. THE HIGH THAT
WILL BUILD IN ON SATURDAY WILL REMAIN IN PLACE INTO MONDAY NIGHT
AND LEAD TO DRY CONDITIONS. THERE ARE HINTS OF A WEAK FRONT MOVING
ACROSS THE AREA ON TUESDAY...BUT WITH MUCH OF THE FORCING STAYING
WELL TO THE NORTH OF THE AREA...WILL GO WITH SILENT 20 POPS FOR
THE WESTERN CWA FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 148 PM EDT TUE SEP 15 2015
A STRENGTHENING SSW WIND WL DOMINATE THIS FCST PERIOD BTWN HI PRES
OVER THE MID ATLANTIC AND LO PRES IN THE HI PLAINS. THE SFC WIND
GUSTS WL BE STRONGEST AT THE MORE EXPOSED IWD AND SAW LOCATIONS.
ALTHOUGH THE STRONGEST WINDS WL OCCUR DURING THE DAYLIGHT HRS...THE
PRES GRADIENT WL BE STRONG ENUF TO CAUSE GUSTY WINDS AT IWD THRU THE
NGT. AT THE MORE SHELTERED CMX SITE...LLWS WL DEVELOP TNGT AS A
NOCTURNAL INVRN DEVELOPS BLO THE AXIS OF STRONGEST WINDS. THE FCST
FOR SAW IS A BIT MORE TRICKY AS THERE MAY BE PERIODS OF GUSTY WINDS
AS WELL TNGT. BUT MAINTAINED FCST LLWS THERE TNGT IN CASE THE NEAR
SFC STABILITY BECOMES SUFFICIENT TO LIMIT MIXING. ALTHOUGH THERE WL
BE MORE MID/HI CLDS LATER TNGT AND WED MRNG ESPECIALLY OVER THE NW
HALF OF UPR MI...LINGERING LLVL DRY AIR WL BRING VFR CONDITIONS THE
ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 321 PM EDT TUE SEP 15 2015
WINDY CONDITIONS ARE SHAPING UP FOR MUCH OF LAKE SUPERIOR INTO WED
AS THE UPPER LAKES WILL BE SITUATED BTWN A LO PRES TROF TO THE NW
AND HI PRES OVER THE MID ATLANTIC STATES. EXPECT S WINDS TO INCREASE
TO AS HI AS 25-30 KTS TONIGHT INTO WED. NOT OUT OF THE QUESTION THAT
THE HIGHEST OBS PLATFORMS WILL SEE GALE FORCE GUSTS. WINDS WILL
DIMINISH SOME WED AFTERNOON/THU...ESPECIALLY OVER THE W HALF OF THE
LAKE. A COLD FRONT WILL PASS THU NIGHT/FRI MORNING...RESULTING IN A
WIND SHIFT TO THE N 10-20 KT FRI NIGHT INTO SAT. LIGHT WINDS WILL
THEN DOMINATE ON SAT INTO SUN AS TRAILING HI PRES MOVES BY. ONCE
THIS HI SHIFTS TO THE E...A S-SW WIND WILL PREVAIL ON MON...BUT
SHOULD BE NO HIER THAN ABOUT 15-20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
323 PM EDT TUE SEP 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 321 PM EDT TUE SEP 15 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WRN TROF/ERN RDG
PATTERN...WITH DEEP SW FLOW ARND SFC HI PRES IN THE MID ATLANTIC
STATES ADVECTING UNSEASONABLY WARM AIR INTO THE UPR GREAT LKS. 12Z
H85 TEMPS WERE 18C AT APX/GRB AND 19C AT MPX. DESPITE STEEP MID LVL
LAPSE RATES AND SOME MODEST H85 THETA E ADVECTION THAT SUPPORTED
SOME SCT SHOWERS/TS OVER NE WI EARLIER THIS MRNG...ABSENCE OF
DYNAMIC FORCING WITH LLVL ACYC FLOW AND VERY SHARP CAPPING/DRY MID
LYR DEPICTED ON THE 12Z MPX RAOB THAT ARE OVERSPREADING THE AREA
HAVE MAINTAINED DRY WX OVER UPR MI. SFC TEMPS HAVE RISEN INTO THE
80S AT MANY PLACES AWAY FM LK MI MODERATION DESPITE SOME PATCHY HI
CLDS.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON TEMPS/WINDS AND SLIM
PCPN CHCS.
TNGT...STRONG SW FLOW...WITH SHARPENING PRES GRADIENT INCRSG H925
WINDS UP TO 40-45 KTS...IS FCST TO DOMINATE THE AREA. NOCTURNAL
COOLING/INVRN WL LIMIT THE SFC WIND GUSTS. ALTHOUGH THESE STRONG
WINDS WL INITIALLY TAP AN AREA OF DRIER LLVL AIR NOW OVER THE LOWER
GREAT LKS...MODELS SHOW THE H85 FLOW VEERING A BIT OVERNGT AND
ADVECTING HIER H85-7 THETA E INTO MAINLY THE NW HALF OF UPR MI
OVERNGT. A NUMBER OF THE MODELS GENERATE SOME PCPN IN THIS AREA
LATE. BUT CONSIDERING THE STRONG CAPPING DEPICTED ON THE 12Z MPX
RAOB...THE ABSENCE OF ANY OTHER SGNFT DYNAMIC FORCING/HGT FALLS AND
RELATIVELY DRY SFC-H7 LYR SHOWN ON THE 12Z NAM FCST SDNGS...OPTED TO
FOLLOW THE DRIER GUIDANCE AND MAINTAIN GOING DRY FCST. THE
COMBINATION OF STRONG WINDS AND INCRSG MID/HI CLDS ACCOMPANYING THE
MSTR RETURN WL RESULT IN A VERY WARM OVERNGT...ESPECIALLY IN THE
DOWNSLOPE AREAS NEAR LK SUP OVER THE NW HALF...WHERE FCST WL TEND
TOWARD THE HI END OF GUIDANCE.
WED...MAINTAINED SOME SCHC POPS OVER THE FAR NW CWA...WHERE SHRTWV
FCST TO LIFT NE THRU FAR NW ONTARIO MAY BE CLOSE ENUF TO AXIS OF
HIER H85-7 THETA E TO GENERATE SOME SHOWERS/TS. THE REST OF THE CWA
WL REMAIN DRY. DAYTIME HEATING/MIXING WL CAUSE THE STRONG LLVL WINDS
TO MIX TO THE SFC...WITH GUSTS AS HI AS 30 TO 35 MPH AT THE MORE
EXPOSED LOCATIONS. WITH H85 TEMPS FCST AS HI AS 20-22C...EXPECT MAX
TEMPS TO CLIMB WELL INTO THE 80S AWAY FM THE COOLING INFLUENCE OF LK
MI. TENDED TOWARD THE HI END OF GUIDANCE FOR MAX TEMPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 338 AM EDT TUE SEP 15 2015
THE CWA WILL CONTINUE TO BE UNDER SW FLOW ALOFT BETWEEN RIDGING TO
THE E AND TROUGHING TO THE W. SEVERAL SHORTWAVES WILL PASS NEARBY
FROM MID TO LATE WEEK.
FOR WED...SLIGHT CHANCE POPS OVER MAINLY THE WRN CWA SEEMS
REASONABLE GIVEN THAT A SHORTWAVE WILL STAY NW OF THE AREA
(SASKATCHEWAN AND FAR NW ONTARIO) AND DRY LOW-MID LEVELS WILL
PREVENT MOST AREAS FROM SEEING PRECIP. EXPECT HIGH TEMPS FROM THE
MID 70S NEAR LAKE MICHIGAN TO THE MID 80S NEAR LAKE SUPERIOR AS SSW
WINDS GUSTING TO 20-25 KTS DOWNSLOPE TOWARD THE BIG LAKE.
PRECIP CHANCES BEGIN INCREASING WED NIGHT AS A STRONGER SHORTWAVE
AND SFC LOW MOVE CLOSER TO THE CWA...ACROSS NRN MN AND INTO ONTARIO.
STILL ONLY HAVE CHANCE POPS WED NIGHT INTO THU AFTERNOON...BUT
SHOWERS AND THUNDERSTORMS BECOME LIKELY THU EVENING AND THU NIGHT AS
THE SFC TROUGH/COLD FRONT MOVE W-E ACROSS THE AREA. THINK THERE
COULD BE SOME STRONG TO SEVERE STORMS THU EVENING AS MUCAPE VALUES
LOOK TO BE 1000-2000 J/KG AND DEEP LAYER SHEAR IS AROUND 30KTS. CAPE
AND EFFECTIVE SHEAR DIMINISH LATER IN THE EVENING AND OVERNIGHT THU
NIGHT AS STORMS BECOME ELEVATED...SO SEVERE THREAT WILL ALSO
DIMINISH. PLENTY OF MOISTURE OVERHEAD WILL ALLOW FOR BRIEF HEAVY
RAINFALL. THU TEMPS LOOK TO BE A LITTLE COOLER THAN WED DUE TO
INCREASED CLOUD COVER...BUT WILL STILL SEE HIGHS ABOVE NORMAL IN THE
70S TO AROUND 80...WARMEST NEAR LAKE SUPERIOR.
LOTS OF UNCERTAINTY FOR FRI INTO SAT AS MODELS VARY ON HANDLING A
SHORTWAVE MOVING UP THE FRONT AND INTO THE GREAT LAKES REGION.
TIMING...TRACK AND STRENGTH OF THE SHORTWAVE WILL GREATLY IMPACT
WEATHER OVER THE CWA. FOR NOW...MODELS ARE IN SOME GENERAL AGREEMENT
THAT MAINLY THE SERN 1/2 TO 2/3 OF THE CWA WILL BE EFFECTED BY
PRECIP...BUT THEY DO DIFFER ON TIMING AND STRENGTH. WILL JUST USE A
CONSENSUS OF GUIDANCE AT THIS TIME. IT WILL BE QUITE A BIT COOLER
BEHIND THE FRONT...EXACTLY HOW MUCH DEPENDS ON PRECIP/CLOUD
COVER...BUT HIGHS IN THE 60S TO LOW 70S SEEMS REASONABLE.
SFC HIGH PRESSURE THEN LOOKS TO MOVE THROUGH OVER THE WEEKEND...WITH
SW FLOW ON THE BACK SIDE EARLY NEXT WEEK. NO PRECIP IS EXPECTED FROM
AT LEAST LATE SAT ON...AND TEMPS WILL GRADUALLY WARM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 148 PM EDT TUE SEP 15 2015
A STRENGTHENING SSW WIND WL DOMINATE THIS FCST PERIOD BTWN HI PRES
OVER THE MID ATLANTIC AND LO PRES IN THE HI PLAINS. THE SFC WIND
GUSTS WL BE STRONGEST AT THE MORE EXPOSED IWD AND SAW LOCATIONS.
ALTHOUGH THE STRONGEST WINDS WL OCCUR DURING THE DAYLIGHT HRS...THE
PRES GRADIENT WL BE STRONG ENUF TO CAUSE GUSTY WINDS AT IWD THRU THE
NGT. AT THE MORE SHELTERED CMX SITE...LLWS WL DEVELOP TNGT AS A
NOCTURNAL INVRN DEVELOPS BLO THE AXIS OF STRONGEST WINDS. THE FCST
FOR SAW IS A BIT MORE TRICKY AS THERE MAY BE PERIODS OF GUSTY WINDS
AS WELL TNGT. BUT MAINTAINED FCST LLWS THERE TNGT IN CASE THE NEAR
SFC STABILITY BECOMES SUFFICIENT TO LIMIT MIXING. ALTHOUGH THERE WL
BE MORE MID/HI CLDS LATER TNGT AND WED MRNG ESPECIALLY OVER THE NW
HALF OF UPR MI...LINGERING LLVL DRY AIR WL BRING VFR CONDITIONS THE
ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 321 PM EDT TUE SEP 15 2015
WINDY CONDITIONS ARE SHAPING UP FOR MUCH OF LAKE SUPERIOR INTO WED
AS THE UPPER LAKES WILL BE SITUATED BTWN A LO PRES TROF TO THE NW
AND HI PRES OVER THE MID ATLANTIC STATES. EXPECT S WINDS TO INCREASE
TO AS HI AS 25-30 KTS TONIGHT INTO WED. NOT OUT OF THE QUESTION THAT
THE HIGHEST OBS PLATFORMS WILL SEE GALE FORCE GUSTS. WINDS WILL
DIMINISH SOME WED AFTERNOON/THU...ESPECIALLY OVER THE W HALF OF THE
LAKE. A COLD FRONT WILL PASS THU NIGHT/FRI MORNING...RESULTING IN A
WIND SHIFT TO THE N 10-20 KT FRI NIGHT INTO SAT. LIGHT WINDS WILL
THEN DOMINATE ON SAT INTO SUN AS TRAILING HI PRES MOVES BY. ONCE
THIS HI SHIFTS TO THE E...A S-SW WIND WILL PREVAIL ON MON...BUT
SHOULD BE NO HIER THAN ABOUT 15-20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
148 PM EDT TUE SEP 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 531 AM EDT TUE SEP 15 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A TROF DEVELOPING OVER THE
WRN CONUS WHICH IS FORCING A BUILDING DOWNSTREAM RIDGE OVER THE ERN
CONUS. RESULTING SW FLOW INTO THE UPPER GREAT LAKES IS GENERALLY
QUIET. HOWEVER...A VERY PRONOUNCED ELEVATED MIXED LAYER/VERY STEEP
MID LEVEL LAPSE RATES OF 8-9C/KM EVIDENT ON 00Z SOUNDINGS ACROSS THE
CNTRL/NRN PLAINS AND UPPER MISSISSIPPI VALLEY IS SUPPORTING A FEW
SHRA/TSRA ACROSS PORTIONS OF CNTRL/SRN WI EARLY THIS MORNING WHERE A
POOL OF HIGHER 700MB THETA-E IS LOCATED PER RAP ANALYSIS. CLOSER TO
HOME...CLR SKIES HAVE BEEN THE RULE OVERNIGHT. HOWEVER...SRLY FLOW
UP LAKE MICHIGAN HAS BEEN ADVECTING HIGHER DWPTS INTO THE COOLER
INTERIOR...RESULTING IN SOME PATCHY FOG/STRATUS.
ANOTHER WARM LATE SUMMER DAY IS ON THE WAY TODAY. ALTHOUGH 850MB
TEMPS WILL BE ON THE ORDER OF 18-20C TODAY...PROBABLY WON`T BE ABLE
TO MIX TO 850MB AND REALIZE THAT WARMTH GIVEN THE STRONG INVERSION
AND LOWER SUN ANGLE THIS TIME OF YEAR. EXPECT MAX TEMPS IN THE UPPER
70S TO MID 80S...WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
HIGHS ALONG THE LAKE MICHIGAN SHORE E OF KESC WILL BE AROUND 70F.
TIGHTENING GRADIENT BTWN NORTHERN PLAINS LOW PRES AND HIGH PRES TO
THE ESE WILL SUPPORT BREEZY SSW WINDS THIS AFTN AS NOTED ON FCST
SOUNDINGS. MIXED LAYER SUPPORTS WIND GUSTS INTO THE 25-30MPH RANGE
MOST AREAS WITH POTENTIAL TO GUST TO AROUND 35MPH WHERE DOWNSLOPE
WARMING AIDS MIXING DEPTH. NOT OUT OF THE QUESTION THAT A FEW
SPRINKLES OR ISOLD -SHRA COULD OCCUR THIS MORNING OVER THE SCNTRL/E
AS POOL OF HIGHER 700MB THETA-E LIFTS NE. WITH VERY DRY AIR BLO THE
10KFT+ HIGH CLOUD BASES...WILL LEAVE FCST DRY FOR NOW AND MONITOR
UPSTREAM PCPN EVOLUTION.
LOW-LEVEL JET CONTINUES TO RAMP UP TONIGHT WITH WINDS AT THE 2KFT
LEVEL UP TO 50-60KT W AND 40-45KT E. COULD BE A SET UP FOR WINDY
CONDITIONS IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR SUCH AS
MARQUETTE. OTHERWISE...WITH STRENGTHENING NOCTURNAL INVERSION...
GUSTS WILL ONLY BE 10-20MPH. THE WINDS WILL KEEP TEMPS UP TONIGHT.
EXPECT MINS IN THE UPPER 50S TO UPPER 60S...WARMEST IN THE DOWNSLOPE
AREAS NEAR LAKE SUPERIOR. WITH PRONOUNCED ELEVATED MIXED LAYER/VERY
STEEP MID LEVEL LAPSE RATES OVER THE AREA...CAN`T COMPLETELY RULE
OUT AN ISOLD SHRA OR TSTM AS LOW-LEVEL JET INCREASES WITH ANOTHER
PUSH OF 700MB THETA-E. HOWEVER...GIVEN THE OVERALL DRY AIR MASS...
POTENTIAL APPEARS TOO LOW TO INCLUDE A MENTION OF PCPN IN FCST. IN
ADDITION...THERE ARE FEWER MODEL RUNS INDICATING PCPN TONIGHT
COMPARED TO PREVIOUS RUNS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 338 AM EDT TUE SEP 15 2015
THE CWA WILL CONTINUE TO BE UNDER SW FLOW ALOFT BETWEEN RIDGING TO
THE E AND TROUGHING TO THE W. SEVERAL SHORTWAVES WILL PASS NEARBY
FROM MID TO LATE WEEK.
FOR WED...SLIGHT CHANCE POPS OVER MAINLY THE WRN CWA SEEMS
REASONABLE GIVEN THAT A SHORTWAVE WILL STAY NW OF THE AREA
(SASKATCHEWAN AND FAR NW ONTARIO) AND DRY LOW-MID LEVELS WILL
PREVENT MOST AREAS FROM SEEING PRECIP. EXPECT HIGH TEMPS FROM THE
MID 70S NEAR LAKE MICHIGAN TO THE MID 80S NEAR LAKE SUPERIOR AS SSW
WINDS GUSTING TO 20-25 KTS DOWNSLOPE TOWARD THE BIG LAKE.
PRECIP CHANCES BEGIN INCREASING WED NIGHT AS A STRONGER SHORTWAVE
AND SFC LOW MOVE CLOSER TO THE CWA...ACROSS NRN MN AND INTO ONTARIO.
STILL ONLY HAVE CHANCE POPS WED NIGHT INTO THU AFTERNOON...BUT
SHOWERS AND THUNDERSTORMS BECOME LIKELY THU EVENING AND THU NIGHT AS
THE SFC TROUGH/COLD FRONT MOVE W-E ACROSS THE AREA. THINK THERE
COULD BE SOME STRONG TO SEVERE STORMS THU EVENING AS MUCAPE VALUES
LOOK TO BE 1000-2000 J/KG AND DEEP LAYER SHEAR IS AROUND 30KTS. CAPE
AND EFFECTIVE SHEAR DIMINISH LATER IN THE EVENING AND OVERNIGHT THU
NIGHT AS STORMS BECOME ELEVATED...SO SEVERE THREAT WILL ALSO
DIMINISH. PLENTY OF MOISTURE OVERHEAD WILL ALLOW FOR BRIEF HEAVY
RAINFALL. THU TEMPS LOOK TO BE A LITTLE COOLER THAN WED DUE TO
INCREASED CLOUD COVER...BUT WILL STILL SEE HIGHS ABOVE NORMAL IN THE
70S TO AROUND 80...WARMEST NEAR LAKE SUPERIOR.
LOTS OF UNCERTAINTY FOR FRI INTO SAT AS MODELS VARY ON HANDLING A
SHORTWAVE MOVING UP THE FRONT AND INTO THE GREAT LAKES REGION.
TIMING...TRACK AND STRENGTH OF THE SHORTWAVE WILL GREATLY IMPACT
WEATHER OVER THE CWA. FOR NOW...MODELS ARE IN SOME GENERAL AGREEMENT
THAT MAINLY THE SERN 1/2 TO 2/3 OF THE CWA WILL BE EFFECTED BY
PRECIP...BUT THEY DO DIFFER ON TIMING AND STRENGTH. WILL JUST USE A
CONSENSUS OF GUIDANCE AT THIS TIME. IT WILL BE QUITE A BIT COOLER
BEHIND THE FRONT...EXACTLY HOW MUCH DEPENDS ON PRECIP/CLOUD
COVER...BUT HIGHS IN THE 60S TO LOW 70S SEEMS REASONABLE.
SFC HIGH PRESSURE THEN LOOKS TO MOVE THROUGH OVER THE WEEKEND...WITH
SW FLOW ON THE BACK SIDE EARLY NEXT WEEK. NO PRECIP IS EXPECTED FROM
AT LEAST LATE SAT ON...AND TEMPS WILL GRADUALLY WARM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 148 PM EDT TUE SEP 15 2015
A STRENGTHENING SSW WIND WL DOMINATE THIS FCST PERIOD BTWN HI PRES
OVER THE MID ATLANTIC AND LO PRES IN THE HI PLAINS. THE SFC WIND
GUSTS WL BE STRONGEST AT THE MORE EXPOSED IWD AND SAW LOCATIONS.
ALTHOUGH THE STRONGEST WINDS WL OCCUR DURING THE DAYLIGHT HRS...THE
PRES GRADIENT WL BE STRONG ENUF TO CAUSE GUSTY WINDS AT IWD THRU THE
NGT. AT THE MORE SHELTERED CMX SITE...LLWS WL DEVELOP TNGT AS A
NOCTURNAL INVRN DEVELOPS BLO THE AXIS OF STRONGEST WINDS. THE FCST
FOR SAW IS A BIT MORE TRICKY AS THERE MAY BE PERIODS OF GUSTY WINDS
AS WELL TNGT. BUT MAINTAINED FCST LLWS THERE TNGT IN CASE THE NEAR
SFC STABILITY BECOMES SUFFICIENT TO LIMIT MIXING. ALTHOUGH THERE WL
BE MORE MID/HI CLDS LATER TNGT AND WED MRNG ESPECIALLY OVER THE NW
HALF OF UPR MI...LINGERING LLVL DRY AIR WL BRING VFR CONDITIONS THE
ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 531 AM EDT TUE SEP 15 2015
WINDY CONDITIONS ARE SHAPING UP FOR LAKE SUPERIOR THRU THU AS LAKE
SUPERIOR WILL BE SITUATED BTWN A LOW PRES TROF TO THE NW AND HIGH
PRES TO THE ESE. SOUTHERLY WINDS WILL SLOWLY RAMP UP TODAY AND WILL
REACH GENERALLY 15-25KT W HALF TO 20-30KT E HALF TONIGHT. NOT OUT OF
THE QUESTION THAT THE HIGHEST OBS PLATFORMS WILL SEE GALE FORCE
GUSTS. WINDS WILL DIMINISH SOME WED/THU...MORE SO OVER THE W HALF OF
THE LAKE. A COLD FRONT WILL PASS THU NIGHT/FRI MORNING WITH
GENERALLY 10-20KT WINDS TO FOLLOW INTO THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1251 PM CDT TUE SEP 15 2015
.DISCUSSION...
Issued at 303 AM CDT TUE SEP 15 2015
Over the next several hours, the development of a few isolated
showers and perhaps a stray thunderstorm continue to looks possible
where accas continues to develop and thicken across eastern KS. A
strong LLJ based around 1-1.5 kft and decent isentropic lift in the
310-315K layer will continue to support initiation through at least
sunrise if not a few hours after, and hi-res model guidance shows a
signal for precipitation by 11-12z with relatively good temporal and
spatial continuity. Any showers/storms that develop will drift east
before dissipating as the nocturnal LLJ diminishes diurnally later
in the morning, allowing skies to clear and temperatures to warm
into the mid to possibly upper 80s this afternoon. As was the case
yesterday, any mixing to a higher height than indicated in models
could bring highs several degrees warmer than forecast, but have
settled with a mixing height of around 925 hPa and somewhat
discounted the more extreme RAP solution which brings surface
temperatures near 90 degrees and surface dewpoints down to the upper
40s. Winds may be just a touch lighter this afternoon than
yesterday, but still with sustained speeds in the upper teens and
gusts to 25-30 mph especially during the late morning and early
afternoon.
The LLJ should focus more to the north and northeast tonight into
Wednesday morning, allowing any possible nocturnal convection to
develop and remain out of the forecast area. As a result, cloud
cover is not expected to hinder temperature rises, and highs could
reach the upper 80s CWA-wide Wednesday afternoon. Wednesday night
into early Thursday morning will be similar, but there is still a
decent signal for cold-pool driven storms sneaking into the
northeastern quadrant of the forecast area around sunrise, and thus
have continued lower-end PoPs for areas along/north of Hwy 36 and
east of STJ from after midnight through the late morning hours
Thursday.
On Thursday, a final lobe of surface low pressure will eject off the
lee-side of the Rockies and into the Dakotas, forcing its associated
cold front across the Plains and into the Great Lakes area Thursday
through Friday. The high temperature forecast Thursday will be
somewhat complicated as convergence ahead of the approaching cold
front enhances southerly surface flow and boundary layer mixing once
again, but while destructive warm-sector convection becomes probable
during the afternoon. Convective initiation should be shallow and
capped Thursday afternoon, then precipitation will become likely by
evening and especially the overnight hours into early Friday morning
along the boundary. The slow-moving nature of the front and PWAT
values on the order of 2 inches (over 150% of normal) may indicate
the potential for flash flooding as rounds of storms develop near
and ahead of the front, and while a few strong to marginally severe
storms are nearly always possible along a robust autumn cold front,
the main concern will likely be the heavy rains and flooding
potential.
After the front pushes out of the region on Friday evening, cooler
temperatures and gradually decreasing low-level moisture will make
for another autumn-like weekend across the region. While upper
heights do not fall quite as dramatically as with last weekend`s
system in the wake of the coming system, highs will likely top out
in the lower to mid 70s Saturday and a touch warmer in the mid to
upper 70s Sunday, before conditions once again moderate to near
normal early next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1235 PM CDT TUE SEP 15 2015
Light showers will continue to dissipate across the area, but south
winds remain gusty through the afternoon and evening before dropping
off this evening. With strong pressure gradient still positioned
across the Central Plains, the lower levels may not completely
decouple and will allow for breezy surface winds overnight. LLWS will
have to be watched is the boundary layer is able to decouple
overnight. Southerly winds will increase tomorrow morning with
scattered cu deck developing by late morning into early afternoon.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...PMM
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1205 PM CDT TUE SEP 15 2015
.UPDATE...
ISSUED AT 1205 PM CDT TUE SEP 15 2015
UPDATED FORECAST A BIT EARLIER AND WILL MAKE A FEW MORE MINOR
CHANGES BEFORE 1230 PM. BRISK SOUTH WINDS MAY REACH CLOSE TO
ADVISORY LEVELS THIS AFTERNOON AS STRONG WINDS ALOFT MIX DOWN.
HIGHS LOOKED ON TRACK...JUST DECIDED TO ADD A SLIGHT CHANCE OF
TSTMS TO OUR FAR WRN COUNTIES LATE THIS AFTN AND EVENING. SOME
RECENT EXPERIMENTAL HRRR RUNS HAVE BEEN SUGGESTING THAT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 254 AM CDT TUE SEP 15 2015
LARGE SCALE FLOW GRADUALLY ALTER FROM NEAR ZONAL CURRENTLY ALONG THE
U.S./CAN BORDER TO A BROAD LOW AMPLITUDE TROF OVER THE WRN/CNTRL
CONUS BY LATE WED NIGHT IN RESPONSE TO PAC NW SHORTWAVE DIGGING DOWN
THE WEST COAST. MODELS IN DECENT AGREEMENT DEPICTING SERIES OF
IMPULSES EJECTING OUT OF THE SWRN STATE THE LIFTING ACROSS THE
CNTRL/NRN PLAINS.
MAIN ISSUE TO CONTEND WITH IS POSSIBLE TSTM DEVELOPMENT LATER
TONIGHT. BNDRY LYR THETA-E ADV STEADILY INCREASES DURING THE AFTN
HOURS JUST AHEAD OF A STAGNANT THERMAL BNDRY/DEEP SFC TROF PROGGED
TO EXTEND FROM ABOUT THE ERN DAKOTAS TO WRN KS EARLY THIS EVENING.
HOWEVER..MODELS ARE SHOWING SEVERAL FACTORS LEADING TO THE
ENVIRONMENT WILL BE TOO WELL CAPPED TO ALLOW FOR ANY STORM
INITIATION. WITH NIL SIGNIFICANT UPPER LEVEL DYNAMIC FORCING
COMBINED WITH 12C 700MB TEMPS/LID STRENGTH INDEX 4C-7C/MARGINAL
INSTABILITY AT BEST...FEEL RELATIVELY CONFIDENT THAT OVERNIGHT POPS
CAN BE REMOVED FROM GOING FCST.
PCPN EVENT PROGGED THUR NIGHT DEFINITELY APPEARS TO BE MUCH MORE
PROMISING. ALL THIS IN PART TO INTENSE WARM FRONT...ASSOCIATED WITH
DEEPENING SFC LOW IN WRN KS...EXTENDING ALONG THE NEB/KS BORDER THEN
INTO NRN MO. INGREDIENTS NEEDED FOR A HEAVY RAINFALL EVENT WILL BE
FOCUSED IN THE VICINITY OF THE SRN CWA WHERE MAXOMEGA WILL PHASE
WITH DEEP LYR MOISTURE/STRONG MID LYR AGEOSTROPHIC FORCING. IN
ADDITION TO THIS...MODELS FOCUS ANOTHER AREA OF PCPN DEVELOPMENT
JUST AFTER MIDNIGHT OVER WRN NEB/SW SD WHERE 310K UPGLIDE INCREASES
SUBSTANTIALLY. GIVEN THIS...WILL ADJUST POPS ACCORDINGLY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 254 AM CDT TUE SEP 15 2015
GFS/ECM IN AGREEMENT PASSING UPPER LVL SHORTWAVE TROF PROMPTS NEARLY
STAGNANT SFC BNDRY IN PROXIMITY OF THE SRN CWA TO BEGIN PUSHING
DEEPER INTO THE CNTRL PLAINS LATE FRIDAY NIGHT. WITH A COOLER AND
MORE STABLE AIR MASS FILLING IN BEHIND...PCPN CHANCES LOOK LESS
LIKELY THE REMAINDER OF THE EXTENDED PDS. THUS WILL OPT TO REMOVE
POPS FROM GOING FCST. OTHERWISE NOTICEABLY COOLER THIS WEEKEND WITH
HIGHS GENERALLY IN THE LOW/MID 70S.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1205 PM CDT TUE SEP 15 2015
VFR CONDITIONS SHOULD PREVAIL. WINDS WILL BE THE MAIN ISSUE...
WITH LOW LEVEL WIND SHEAR DEVELOPING AGAIN THIS EVENING. SOME
ISOLD TSRA POSSIBLE...MAINLY AT KOFK...BUT CHANCES TOO LOW TO
MENTION IN TAFS AT THIS TIME.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
300 PM CDT TUE SEP 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 300 PM CDT TUE SEP 15 2015
PRECIP CHANCES THROUGHOUT THE PERIOD WILL BE THE MAIN CHALLENGE
FOR THE SHORT TERM.
WV LOOP SHOWS SOUTHWESTERLY FLOW ALOFT AND A WEAK LEAD SHORTWAVE
MOVING THROUGH. THE WARM FRONT HAS LIFTED THROUGH THE NORTHWESTERN
COUNTIES AND IS NEAR THE CANADIAN BORDER. THINK THE WARM FRONT
WILL CONTINUE TO LIFT NORTH THROUGH THE LATE AFTERNOON AND THE RAP
AND HRRR HAVE CONVECTIVE DEVELOPMENT MOSTLY IN SOUTHERN CANADA.
THIS SEEMS REASONABLE...GIVEN THAT ALTHOUGH THERE IS PLENTY OF
WARMTH AND MOISTURE IN OUR CWA ACROSS THE WARM SECTOR...THERE IS
ALSO SOME VERY WARM 700MB TEMPS THAT ARE KEEPING US CAPPED.
SHOWERS THAT MOVED THROUGH THE NORTHWESTERN CWA EARLIER TODAY HAVE
DISSIPATED OR MOVED OFF TO THE NORTH...SO WE SHOULD REMAIN DRY
THROUGH MUCH OF THE EVENING...BUT SOME PRECIP WILL BE POSSIBLE
TOWARDS MIDNIGHT AS THE SFC TROUGH MOVES EAST AND THE COLD FRONT
MOVES INTO THE CWA. MODELS ALL HAVE PRECIP FAIRLY SPOTTY AND
WEAK...SO KEPT POPS FAIRLY LOW THROUGH TONIGHT.
TOMORROW...SOUTHWESTERLY FLOW ALOFT CONTINUES...WITH THE NEXT
SHORTWAVE ARRIVING ON DECK OVER MT/WY. THE SFC TROUGH AND COLD
FRONT THAT MOVES THROUGH TONIGHT WILL STALL OUT OVER THE
SOUTHEASTERN COUNTIES AND BEGIN TO WASH OUT AS A STRONGER LOW
DEVELOPS OVER SOUTHWESTERN ND. TEMPS WILL BE IN THE 70S TO THE
NORTH OF THE BOUNDARY AND NEAR 80 IN THE SOUTH. THE GFS HAS THE
SOUTHEASTERN COUNTIES DESTABILIZING BY AFTERNOON AHEAD OF THE
FRONT...BUT DEEP LAYER BULK SHEAR IS STILL AROUND 30KTS OR SO.
THINK THE BETTER CHANCES FOR PRECIP WILL BE ON WEDNESDAY EVENING
AS THE UPPER SHORTWAVE COMES OUT AND THE FRONT LIFTS NORTH AS THE
SFC TROUGH MOVES INTO THE RED RIVER VALLEY. THE MODELS ALL HAVE
THE LOW ON DIFFERENT TRACKS...BUT THERE IS ENOUGH AGREEMENT TO GO
WITH FAIRLY HIGH POPS IN THE NORTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE SEP 15 2015
THURSDAY THROUGH FRIDAY...SOUTHWESTERLY FLOW ALOFT CONTINUES WITH
SOME FAIRLY DECENT SHORTWAVES MOVING THROUGH. THE FIRST WILL HELP
PUSH THE SFC TROUGH THROUGH THE CWA AND BRINGING PRECIP AND A COLD
FRONT INTO THE AREA. CONTINUED TO KEEP POPS IN THE HIGH CHANCE
RANGE MAINLY IN THE NORTHERN CWA AS THEY SEEM TO HAVE THE BEST
SHOT GIVEN THE TRACK OF THE UPPER WAVE. AFTER A BREAK IN PRECIP ON
THURSDAY NIGHT THERE MAY BE A BIT IN THE SOUTHERN CWA ON FRIDAY AS
THE NEXT SHORTWAVE COMES OUT ON A MORE SOUTHERLY TRACK.
TEMPERATURES SHOULD BE IN THE 60S AND 70S ON THURSDAY BUT WITH
SOME PRETTY GOOD COLD AIR ADVECTION AND CLOUDS READINGS WILL BE IN
THE 60S FOR FRIDAY.
FOR SAT THROUGH TUE...TEMPERATURES SHOULD WARM ABOVE NORMAL AND
REMAIN THAT WAY THROUGH THE PERIOD. GENERAL ZONAL FLOW IS EXPECTED
WITH WARMING MID LEVEL TEMPS. THERE IS A LOW CHANCE FOR PERHAPS SOME
SHOWERS BY NEXT TUE...BUT OVERALL IT WILL BE A DRY AND WARM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1215 AM CDT TUE SEP 15 2015
A WARM FRONT APPROXIMATELY LOCATED FROM NEAR A KDVL TO KROX LINE
AS OF 18Z TUESDAY WILL CONTINUE LIFTING NORTH THROUGH 00Z. IFR
CIGS AT KDVL WILL IMPROVE TO VFR AFTER 19Z WITH THE REMAINING
TERMINALS REMAINING VFR. GUSTY SOUTH-SOUTHEASTERLY WINDS OF 15KT-
30KT CAN BE EXPECTED SOUTH OF THE WARM FRONT...DECREASING BY
SUNSET. A COLD FRONT WILL THEN SWEEP THROUGH KDVL BY 06Z
WEDNESDAY AND APPROACH KBJI BY AROUND 18Z WEDNESDAY. SHOWERS AND
MVFR CIGS ARE POSSIBLE BEHIND THE COLD FRONT. FOR NOW HAVE
INTRODUCED A VCSH IN ALL TERMINALS EXCEPT KDVL. WILL CONTINUE TO
LOOK AT THE POTENTIAL FOR MVFR CIGS BEHIND THE FRONTAL PASSAGE AT
THE 00Z TAF ISSUANCE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/DK
AVIATION...SIMOSKO
AREA FORECAST DISCUSSION
NWS BISMARCK ND
101 PM CDT TUE SEP 15 2015
.UPDATE...
ISSUED AT 1250 PM CDT TUE SEP 15 2015
SURFACE LOW PRESSURE OVER WEST CENTRAL NORTH DAKOTA WITH A WARM
FRONT EXTENDING EAST NORTHEAST INTO NORTHEAST NORTH DAKOTA. LOW
STRATUS AND FOG REMAIN OVER THE FAR NORTHERN TIER COUNTIES BUT
EXPECT VISIBILITIES IN THE FAR NORTHWEST AND NORTH CENTRAL TO
IMPROVE EARLY THIS AFTERNOON.
SHOWERS CONTINUE TO LIFT NORTHEAST THROUGH CENTRAL NORTH DAKOTA. A
LITTLE ELEVATED THUNDER EARLIER THIS MORNING ACROSS THE SOUTH
CENTRAL...BUT NOW AS THEY LIFT INTO A MORE STABLE ATMOSPHERE...THE
THREAT OF THUNDER HAS LESSENED. KEPT SOME SHOWERS FROM THE JAMES
RIVER VALLEY TO THE TURTLE MOUNTAINS EARLY THIS AFTERNOON. THEN
DRY UNTIL THE NEXT WAVE PRODUCES FORCING OVER THE SOUTHWEST BY
EARLY EVENING. THIS WILL BRING SLIGHT CHANCE TO CHANCE POPS
SPREADING WEST TO EAST TONIGHT.
UPDATED SKY COVER AND POPS BASED ON LATEST SATELLITE/RADAR
IMAGERY. ALSO LOWERED TEMPERATURES ACROSS THE NORTH DUE TO THE
EXTENSIVE CLOUD COVER.
UPDATE ISSUED AT 927 AM CDT TUE SEP
15 2015
LOW PRESSURE OVER SOUTHEAST MONTANA INTO NORTH CENTRAL SOUTH
DAKOTA WITH A WARM FRONT NORTHEAST FROM HERE INTO NORTHERN
MINNESOTA. A GOOD PORTION OF CENTRAL AND WESTERN NORTH DAKOTA
REMAIN NORTH OF THE FRONT THIS MORNING...THUS LOW STRATUS AND FOG
REMAIN AN ISSUE THROUGH THE MORNING HOURS. HAVE ADJUSTED WEATHER
AND SKY COVER TO INCREASE CLOUD FOG COVERAGE THROUGH THIS
MORNING...ESPECIALLY ACROSS THE NORTH. SHOWERS ACROSS CENTRAL
NORTH DAKOTA LIFTING NORTHEAST. THERE IS SOME SLIGHT TO MODERATE
INSTABILITY ALOFT TODAY WITH STRONG BULK SHEAR. THE WAVE LIFTING
THROUGH CENTRAL NORTH DAKOTA AT THIS TIME IS PRODUCING ENOUGH LIFT
TO OVERCOME CONVECTIVE INHIBITION...AND THERE HAVE BEEN A FEW
LIGHTING STRIKES WITH THIS CONVECTION. HAVE ADDED A MENTION OF
THUNDER THIS MORNING.
UPDATE ISSUED AT 737 AM CDT TUE SEP 15 2015
SENT OUT A QUICK UPDATE TO ADD A MENTION OF FOG TO PORTIONS OF THE
SOUTH CENTRAL THIS MORNING.
UPDATE ISSUED AT 638 AM CDT TUE SEP 15 2015
LATEST RADARS SHOW THE AREA OF SHOWERS CONTINUES TO MOVE NORTH
THROUGH WESTERN NORTH DAKOTA. PATCHY FOG ALSO EXTENDS ACROSS THE JAMES
RIVER VALLEY. THE FOG SHOULD LIFT AROUND SUNRISE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE MAIN FOCUS FOR THE SHORT TERM WILL BE THUNDERSTORM CHANCES.
A SURFACE LOW WILL CONTINUE TO PUSH OUT OF EASTERN MONTANA AND
INTO WESTERN NORTH DAKOTA TODAY...DRAGGING WITH IT A WARM FRONT
ACROSS THE REGION. SCATTERED SHOWERS ARE POSSIBLE ALONG THE WARM
FRONT THIS MORNING. BY THIS AFTERNOON MOST OF WESTERN AND CENTRAL
NORTH DAKOTA WILL BE IN THE WARM SECTOR. TEMPERATURES ARE EXPECTED
TO RISE INTO THE MID TO UPPER 80S ACROSS MOST OF THE REGION.
STRONG MOISTURE ADVECTION WILL OCCUR AT THE SURFACE WITH DEWPOINTS
IN THE MID 60S LIKELY. HOWEVER...RELATIVELY WARM AND DRY MID-
LEVELS (AS SEEN IN RAP AND NAM FORECAST SOUNDINGS) COULD LIMIT
AFTERNOON CONVECTION. IF THUNDERSTORMS DO DEVELOP THIS
AFTERNOON...THEY COULD BECOME STRONG WITH GUSTY WINDS AND SMALL
HAIL...WITH CAPE AROUND 1000 J/KG...30+ KNOTS OF SHEAR AND STEEP
LAPSE RATES FORECAST. THIS EVENING WILL SEE THE BEST CHANCE FOR
THUNDERSTORMS WHEN UPPER LEVEL SUPPORT ARRIVES VIA A SHORT WAVE
TROUGH AND JET STREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE SEP 15 2015
THE EXTENDED BEGINS WEDNESDAY AND FEATURES A LONGWAVE TROUGH OVER
THE WESTERN US WITH A DOWNSTREAM BROAD RIDGE OVER THE GREAT
LAKES. THIS PLACES THE NORTHERN PLAINS IN A SOUTHWEST FLOW REGIME
ALOFT THAT WILL BRING SHORTWAVE ENERGY INTO THE NORTHERN PLAINS
BY WEDNESDAY NIGHT AND THURSDAY. THIS WILL END UP BEING THE MOST
ACTIVE PERIOD FOR THUNDERSTORMS. AFTER THE TROUGH AXIS MOVES
THROUGH A SECOND SHORTWAVE WILL BRUSH THE SOUTHERN SECTIONS OF THE
STATE ON FRIDAY. OTHERWISE A DRY PERIOD WITH GRADUAL MODERATING
TEMPERATURES WILL TAKE HOLD FOR THE WEEKEND.
MODELS APPEAR IN GOOD AGREEMENT ON THESE GENERAL FEATURES. A COLD
FRONT ASSOCIATED WITH THE SHORT WAVE WILL MOVE ACROSS THE STATE
WEDNESDAY AND WEDNESDAY NIGHT AND BE THE FOCUS FOR THUNDERSTORMS.
COOLER AIR BEHIND THE FRONT THURSDAY WILL MEAN HIGHS ONLY IN THE
UPPER 50S NORTH TO THE 70S SOUTHEAST. THE BEST CHANCE FOR
PRECIPITATION WILL BE ACROSS THE NORTH WITH LIKELY TO DEFINITE
POPS BY WEDNEDAY NIGHT. LINGERING SHOWERS WILL REMAIN ACROSS THE
NORTH AND EAST THURSDAY. CLEARING SKIES WITH A SLOW MODERATION IN
TEMPERATURES FOR THE WEEKEND THROUGH MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1250 PM CDT TUE SEP 15 2015
MVFR-IFR CEILINGS REMAIN AT KISN AND KMOT EARLY THIS AFTERNOON TO
THE NORTH OF A WARM FRONT LIFTING NORTH THROUGH THE STATE. DO
EXPECT CEILINGS TO IMPROVE AT THESE AERODROMES EARLY THIS
AFTERNOON. SOUTHERLY WINDS EXPECTED THIS AFTERNOON. A COLD FRONT
WILL MOVE THROUGH WESTERN AND CENTRAL NORTH DAKOTA TONIGHT
SHIFTING WINDS NORTHWEST. A FEW SCATTERED SHOWERS ARE ALSO
POSSIBLE BUT NOTHING MORE THAN A VCSH AT THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...WAA
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1157 AM CDT TUE SEP 15 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.UPDATE...
ISSUED AT 410 AM CDT TUE SEP 15 2015
ALREADY ADDED TSRA TO PARTS OF CENTRAL AND EAST CENTRAL WISCONSIN
AN HOUR AGO BUT RADAR TRENDS SHOW A SMALL CLUSTER OF CONVECTION
OVER SOUTHERN PORTIONS OF MTW AND CALUMET COUNTIES WITH A
DEPARTING VORT AND THEN A SECOND AREA WITHE WAA PCPN WITH THE LLJ
STILL WORKING INTO CENTRAL WISCONSIN. NO RECENT LIGHTNING STRIKES
OVER CENTRAL WI BUT CONVECTION WAS SHOWING A GRADUAL DECREASE.
THE CONVECTION WAS ELEVATED.
&&
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
OVERALL DRY QUIET AND ABOVE NORMAL TEMPERATURES THROUGH MID WEEK.
EARLY THIS MORNING ISOLATED TO SCATTERED CONVECTION WAS OCCURRING
IN THE BROAD WAA SECTOR FROM SOUTHERN MINNESOTA TO THE SOUTH HALF
OF WISCONSIN. CONVECTION OVER WESTERN WISCONSIN PRIMARILY WARM
AIR ADVECTION WITH THE STRONGER LLJ...WHILE CONVECTION CENTERED
AROUND FOND DU LAC COUNTY ASSOCIATED WITH A WEAK VORT SLIDING OVER AS
PER WATER VAPOR LOOP EARLY THIS MORNING. HRRR MODEL SLIDE WEAK
CONVECTION OVER THE SOUTHERN TWO THIRDS OF THE FORECAST AREA EARLY
THIS MORNING. WILL KEEP THE ISOLD SPRINKLES GOING THIS MORNING DUE
TO FALLING FROM MID LEVEL CLOUDS BUT MONITOR FOR ANY NEEDED
MENTION OF TSRA TO THE AREA TO AROUND DAYBREAK. CONVECTION
EXPECTED TO DISSIPATE LATER MORNING AS THE VORT SLIDES EAST AND
THE WARM AIR ADVECTION MIXES OUT TO PROVIDE AN OVERALL DRY DAY.
LITTLE CHANGED IN THE FORECAST FOR TONIGHT...CONTINUED WAA IN THE
SOUTHWEST FLOW AND LLJ WILL BRING A SMALL CHANCE OF CONVECTION TO
THE NORTHWEST HALF TONIGHT. WHAT CONVECTION DEVELOPS TUESDAY
NIGHT WILL TAPER OFF AGAIN WEDNESDAY MORNING FOR ANOTHER MILD
SEPTEMBER DAY WEDNESDAY. A LITTLE MORE MID TO UPPER CLOUDS MAY
FILTER INTO NORTH CENTRAL WISCONSIN LATER WEDNESDAY AS A NORTHERN
PLAINS FRONTAL SYSTEM VERY SLOWLY APPROACHES THE REGION.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 233 AM CDT TUE SEP 15 2015
MAIN FCST SYSTEM OF INTEREST TO BE THE MOVEMENT OF A SHORTWAVE
TROF FROM THE WEST COAST MID-WEEK...TO THE GREAT LAKES AT THE END
OF THE WEEK. WARM/INCREASINGLY MORE HUMID AIR MASS TO PUSH INTO WI
AHEAD OF THIS APPROACHING UPR TROF WHICH WL LEAD TO AN UNSETTLED
WEATHER PERIOD FROM WED NGT THRU FRI NGT. THE MEAN FLOW TURNS
ZONAL FOR EARLY NEXT WEEK WITH DRIER/COOLER AIR MASS SPREADING
OVER THE REGION.
PREVAILING SW WIND WL CONT INTO THE WRN GREAT LAKES WED NGT WITH
WAA AND A SHORTWAVE HEADED TOWARD NE WI. ENUF MOISTURE MAY BE
PRESENT TO BRING AT LEAST A SMALL CHC OF SHWRS/TSTMS TOWARD CNTRL
WI...ESPECIALLY AFTER MIDNGT. OTHERWISE...CLOUDS SHOULD CONT TO
INCREASE/THICKEN THRU THE NGT WITH MIN TEMPS MAINLY IN THE LWR TO
MID 60S. A STRONG AREA OF LOW PRES IS FCST TO MOVE FROM THE NRN
PLAINS NEWD INTO SW ONTARIO ON THU AND PULL A CDFNT EWD TOWARD THE
MN/WI BORDER BY 00Z FRI. THE STRONGER MID-LEVEL FORCING IS
ADVERTISED BY THE MODELS TO REMAIN NEAR THE SFC LOW...THEREBY
LEAVING THE CDFNT AS THE MAIN TRIGGER FOR PCPN DEVELOPMENT. SINCE
THE FRONT IS STILL WELL TO OUR WEST...IT MAY BE DIFFICULT FOR PCPN
TO PUSH TOO FAR EWD. WL CONT TO FOCUS HIGHER POPS OVER CNTRL WI...
BUT MAY TRIM VALUES A BIT. ANOTHER WARM DAY IS EXPECTED WITH MAX
TEMPS IN THE MID TO UPR 70S NORTH/LAKESHORE...AROUND 80 DEGS
SOUTH.
MODELS SEND THE CDFNT INTO ERN WI THU NGT (GFS A TAD FASTER)...
ACCOMPANIED BY SEVERAL SHORTWAVES MOVING NEWD THRU THE MEAN SW
FLWO ALOFT. PREVIOUS SHIFT ALREADY HAD LIKELY POPS ACROSS THE
ENTIRE FCST AREA WHICH STILL LOOKS VALID AT THIS TIME. IF THERE IS
A QUESTION...IT IS THE SPEED OF THE CDFNT AND WHETHER SHWR/TSTM
ACTIVITY WL BEGIN TO DIMINISH OVER CNTRL WI LATE THU NGT. MAY END
UP SPLITTING THE POP GRID AND SHOW A DIMINISHING TREND IN THE POPS
FOR CNTRL WI. MIN TEMPS TO RANGE FROM THE MID TO UPR 50S
N-CNTRL...LWR 60S E-CNTRL WI. FRI`S FCST IS A BIT TRICKY AS THE
MODELS INDICATE A SFC WAVE TO DEVELOP ON THE TAIL OF THE CDFNT AND
MOVE NE TOWARD THE MID-MS VALLEY. MEANWHILE...THE SHORTWAVE TROF
WL BE SWEEPING EWD ACROSS THE NRN PLAINS WITH VARIOUS SHORTWAVES
EMBEDDED WITHIN THE TROF. ANY BREAK IN THE PCPN CHCS APPEAR SHORT-
LIVED AS SHWRS/TSTMS CONVERGE ON WI...ESPECIALLY BY FRI AFTERNOON.
MAY NEED TO TWEAK POPS UP A BIT AS A RESULT. MAX TEMPS TO COOL A
LITTLE FROM PREVIOUS DAYS WITH READINGS IN THE MID TO UPR 60S
N-CNTRL...LWR TO MID 70S E-CNTRL WI.
THE SFC WAVE AND SHORTWAVE TROF CONVERGE ON THE GREAT LAKES FRI
NGT WHICH SHOULD BRING A GOOD CHC FOR ADDITIONAL SHWRS/TSTMS TO NE
WI. THE BACK EDGE OF ANY LINGERING SHWRS MAY AFFECT ERN WI INTO
SAT MORNING...OTHERWISE HI PRES IS FCST TO BUILD ACROSS THE
MIDWEST AND BRING INCREASING SUNSHINE TO THE REGION FOR A GOOD
PART OF SAT. MAX TEMPS SHOULD BE CLOSE TO NORMAL WITH READINGS IN
THE MID 60S TO AROUND 70S DEGS. THIS AREA OF HI PRES TO LIFT NE
INTO THE GREAT LAKES FOR THE LATTER HALF OF THE WEEKEND...THEREBY
BRINGING QUIET WEATHER CONDITIONS TO NE WI WITH TEMPS HOLDING
SLIGHTLY ABOVE NORMAL. A RETURN FLOW DEVELOPS OVER WI BY NEXT MON
WITH WINDS BECOMING S-SW. NO TRIGGER IS EVIDENT...THUS NO PCPN
ANTICIPATED THRU MON. TEMPS ON MON MAY ADD A COUPLE OF DEGS FROM
SUNDAY WITH MOST LOCATIONS IN THE UPR 60S TO LWR 70S.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1150 AM CDT TUE SEP 15 2015
VFR CONDITIONS SHOULD PREVAIL THROUGH WEDNESDAY EVENING. LATER
THIS EVENING AND OVERNIGHT...ELEVATED CONVECTION IS EXPECTED TO
DEVELOP. A FEW SHOWERS AND PERHAPS A THUNDERSTORM WILL BE
POSSIBLE FROM A MID DECK OF CLOUDS...MAINLY ACROSS CENTRAL INTO
NORTH-CENTRAL WISCONSIN. WENT WITH VCSH IN THE 18Z TAFS AT
KRHI/KAUW/KCWA. IF A SHOWER DID MOVE ACROSS ONE THOSE AIRPORTS...
IT WOULD NOT LAST FOR MORE THAN 10 MINUTES. OTHERWISE...ANOTHER
NIGHT OF LOW LEVEL WIND SHEAR IS EXPECTED AT ALL THE TAF SITES.
CONTINUED THIS SCENARIO IN THE 18Z TAFS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......ECKBERG