Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/17/15
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 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
940 PM EDT WED SEP 16 2015
.DISCUSSION...
...NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS STORMS WITH LOCAL HEAVY
RAIN THROUGH FRI...
EVENING SOUNDINGS SHOW AN NEARLY SATURATED AIRMASS FROM SFC-CIG WITH
PWAT VALUES RUNNING AOA 2.2" ACRS THE PENINSULA. WINDS ALONG THE E
FL COAST ARE ONSHORE THRU THE SFC-H85 LYR...ROUGHLY PARALLEL TO THE
COAST THRU THE H85-H50 LYR...BCMG OFFSHORE ABV H50. RAP ANALYSIS
SHOWS THE CYCLONE OVER THE SE GOMEX IS TRAPPED BY DEEP LYR RIDGING
THAT DOMINATES WX PATTERN E OF THE CONTINENTAL DIVIDE...AXIS EXTENDS
FROM THE NW GOMEX TO THE NEW ENGLAND COAST...THE H85-H50 STREAMLINES
LOOK CURIOUSLY LIKE A MIRROR IMAGE OF AN OMEGA BLOCKING PATTERN.
LATEST RADAR TREND SHOWS MOST OF THE LATEST ROUND OF PRECIP HAS
LIFTED N OF I-4 AND IS DISPLAYING SOME BANDING LIKE FEATURES AS THE
LOW OVER THE GOMEX SPINS IN PLACE. TO THE SOUTH...A NEW BATCH OF
LIGHT PRECIP PUSHING UP FROM PALM BEACH COUNTY...BASED ON THE LATEST
WIND FIELDS THIS WILL CONSIST MAINLY OF LIGHT DEBRIS RAIN GENERATED
BY STRONG SHRAS/TSRAS THAT DVLPD OVER S FL A FEW HRS AGO. INTERIOR
LOOKS QUIET FOR THE FOR THE NEXT SVRL HRS.
TRAPPED BY THE RIDGING OVER THE SRN TIER STATES...THE GOMEX LOW WILL
REMAIN NEARLY STATIONARY OVERNIGHT. INTERACTION WITH THE RIDGE WILL
GENERATE A STEADY ONSHORE FLOW ACRS CENTRAL FL THRU THE H100-H70 LYR
WILL MAKE DECOUPLING UNLIKELY. GIVEN THE SATURATED NATURE OF THE LCL
AIRMASS COUPLED WITH THE ONSHORE FLOW...WILL KEEP CHC/LKLY POPS IN
FOR THE COASTAL COUNTIES. WILL DROP POPS OVER THE INTERIOR DOWN TO
SLGT CHC AFT 08Z AS THE S/SERLY MID LVL FLOW SUGGESTS PRECIP MOTION
MORE PARALLEL TO THE COAST THAN PERPENDICULAR. SFC DEWPOINTS IN THE
L/M70S COUPLED WITH DENSE CLOUD COVER AND ONSHORE FLOW SUGGEST MIN
TEMPS IN THE M/U70S BY DAYBREAK.
&&
.AVIATION...THRU 18/00Z
SFC WINDS: THRU 17/14Z...E/NE 3-6KTS INTERIOR SITES...5-7KTS COASTAL
SITES. AFT 17/14Z...E/NE 8-12KTS ALL SITES.
VSBY/WX/CIGS: THRU 17/08Z...CHC MVFR SHRAS/SLGT CHC IFR TSRAS
COASTAL SITES...PREVAILING VFR INTERIOR SITES WITH OCNL MVFR CIGS.
BTWN 17/08Z-17/12Z...LKLY MVFR SHRAS/SLGT CHC IFR TSRAS BTWN
KMLB-KSUA...CHC MVFR SHRAS/SLGT CHC IFR TSRAS BTWN KMLB-KOMN...SLGT
CHC MVFR SHRAS INTERIOR SITES. AFT 17/12Z...LIKELY MVFR SHRAS/SLGT
CHC IFR TSRAS ALL SITES.
&&
.MARINE...
WEAK STORM SYSTEM OVER THE SE GOMEX WILL COMBINE WITH DEEP LYR
RIDGING OVER ERN SEABOARD TO GENERATE A GENTLE TO MODERATE ERLY
BREEZE ACRS THE LCL ATLC OVERNIGHT. THE PERSISTENT ONSHORE FLOW WILL
CONTINUE TO PUSH A 2-3FT SWELL TOWARD THE COAST...KEEPING SEAS IN
THE 3-4FT RANGE AREAWIDE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH THURSDAY EVENING FOR COASTAL VOLUSIA COUNTY-
INDIAN RIVER-MARTIN-NORTHERN BREVARD COUNTY-SOUTHERN
BREVARD COUNTY-ST. LUCIE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX....KELLY
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 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 COLUMBIA SC
954 PM EDT WED SEP 16 2015
.SYNOPSIS...
MOISTURE WILL OCCUR IN AN ONSHORE FLOW BUT THE DEEPER MOISTURE
WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. EXPECT WIDELY
SCATTERED SHOWERS IN THE CSRA AND SOUTHEAST MIDLANDS THROUGH
THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ONSHORE FLOW WILL OCCUR BUT THE BEST MOISTURE SHOULD REMAIN JUST
OFF TO THE SOUTH AND EAST OF THE FORECAST AREA. THERE WILL
CONTINUE TO BE A TIGHT NORTH TO SOUTH MOISTURE GRADIENT OVERNIGHT.
THE MODELS CONTINUE TO INDICATE WEAK ISENTROPIC LIFT AND MOISTURE
FLUX INTO THE SOUTHEAST MIDLANDS AND CSRA...BUT THE FOCUS WILL
REMAIN SOUTH AND EAST OF THE CWA. GIVEN WEAK ISENTROPIC LIFT AND
LIMITED MOISTURE...A FEW SPRINKLES ARE POSSIBLE MAINLY IN THE
EXTREME SOUTHERN COUNTIES IN THE CSRA...WITH BETTER SHOWER
ACTIVITY REMAINING ACROSS SOUTHEASTERN GA AND SOUTHERN SC. THE
TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
PERSISTENT MID/UPPER LEVEL TROUGH ACROSS THE SOUTHEAST WILL
GRADUALLY WEAKEN AND BEGIN TO LIFT OUT TO THE NORTHEAST. COASTAL
TROUGH/WEAK LOW AND ITS ASSOCIATED MOISTURE WILL BEGIN TO SHIFT
EAST/NORTHEAST THURSDAY INTO FRIDAY. A FEW SHOWERS POSSIBLE IN THE
EXTREME SOUTHEAST PORTION OF THE CWA THURSDAY...CONTINUE DRY
FORECAST FRIDAY. WITH AIR MASS MODIFICATION...WARMING SLIGHTLY
INTO FRIDAY. TEMPERATURES WILL BE CLOSE TO NORMAL...EXCEPT COOLER
IN THE ERN PORTION OF THE CWA DUE TO ADDITIONAL CLOUDS ON
THURSDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN THE DOMINATE FEATURE THROUGH THE
WEEKEND. A WEAK COLD FRONT AND ASSOCIATED SHORT WAVE WILL APPROACH
THE AREA MONDAY INCREASING THE THREAT OF CONVECTION LATE MONDAY
INTO TUESDAY. ONCE AGAIN...LOOKS LIKE THE MID/UPPER LEVEL SYSTEM
WILL CLOSE OFF ACROSS THE EAST BY MID WEEK. THIS WILL KEEP A
CHANCE OF SHOWERS IN THE FORECAST THROUGH THE MIDDLE OF NEXT WEEK.
TEMPS WILL MODERATE HEADING INTO THE WEEKEND WITH HIGHS IN THE
UPPER 80S TO POSSIBLY LOWER 90S IN A FEW AREAS OVER THE WEEKEND
BEFORE COOLING DOWN SLIGHTLY NEXT WEEK. EXPECT OVERNIGHT LOWS TO
BE SEASONAL IN THE LOWER/MIDDLE 60S.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
THE TIGHT MOISTURE GRADIENT WILL REMAIN NEAR THE FORECAST AREA
THROUGH THE TAF PERIOD WITH DRY HIGH PRESSURE NORTH OF THE AREA AND
A LONG-FETCH ONSHORE FLOW MAINLY SOUTH OF THE AREA. THE NEAR-SURFACE
LAYER SHOULD REMAIN RELATIVELY DRY ASSOCIATED WITH HIGH PRESSURE
JUST NORTH OF THE AREA BUT THE TIGHT MOISTURE GRADIENT ADDS
UNCERTAINTY TO THE FORECAST. NAM AND RAP BUFKIT TIME SECTIONS
INDICATED MVFR CIGS DEVELOPING LATE TONIGHT MAINLY IN THE SOUTH PART
AFFECTING THE AGS...DNL...AND OGB TERMINALS. VFR CONDITIONS SHOULD
RETURN BY AROUND 15Z THURSDAY.
EXTENDED AVIATION OUTLOOK...AN ONSHORE FLOW MAY RESULT IN PERIODS
OF MVFR OR IFR CONDITIONS DURING THE OUTLOOK PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...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 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 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 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 PADUCAH KY
608 PM CDT WED SEP 16 2015
.UPDATE...
Issued at 605 PM CDT WED SEP 16 2015
Updated Aviation section for 00Z TAF Issuance.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 303 PM CDT WED SEP 16 2015
Isolated showers over south central Missouri have done a good job
of staying to the west of our region this afternoon. Cannot
completely rule out one slipping east into Ripley or Carter
counties, but will leave the forecast dry, as the HRRR and WRF
runs really struggle to move the activity tangibly east.
The ridge aloft will be suppressed a bit Thursday night, and this
may allow some convection to drift off of the cold front and
possibly down to the I-64 corridor. The 12Z NAM was rather
agressive in bringing convection into our forecast area, but most
other models keep any such activity well to the north. The 12Z WRF
runs were split with one wet and the other dry. Will keep a slight
chance very late Thursday night through Friday morning. If
anything does reach the area it is expected to dissipate or move
east by 18Z, so the entire area should be dry Friday afternoon.
The cold front is expected to move through the region late Friday
night and mostly Saturday morning. There is some variability in
the timing, with the 12Z NAM holding it up over our southeast
late Saturday afternoon. If this happens there could be some
significant instability to play with. However, it has litte
support from any other 12Z models. Have trended a bit faster/sooner
with the frontal passage, and kept only small chance PoPs in the
northwest Friday night, and through the entire area through the
day.
As for temperatures, tried to lean toward the warmer MAV/EC
guidance for highs, which could result in some areas reaching 90
by Friday afternoon. The cold front will knock temperatures back
to normal levels Saturday. Lows will trend warmer through the
period. Consensus of guidance has the lows well in line.
.LONG TERM...(Saturday night through Wednesday)
Issued at 303 PM CDT WED SEP 16 2015
Models continue to show an upper level trof moving across the middle
Mississippi and lower Ohio Valleys Sunday into Sunday night. GFS
pretty much keeps us dry, and the latest ECMWF is trending toward
the GFS, and it now only generates very light QPF across our
southern half of counties. Continued with just slight chance pops
for showers across our far west counties in southeast Missouri on
Sunday, and our southern half of counties Sunday night and Monday.
After Monday, surface high pressure and upper level ridging will
keep us dry.
In the wake of the cold front, temperatures Saturday night will cool
down to near seasonal readings in the 50s, and Sunday through
Tuesday temperatures will be unseasonably cool as we remain in north
to northeast flow. By Wednesday we will moderate closer to seasonal
readings.
&&
.AVIATION...
Issued at 605 PM CDT WED SEP 16 2015
Diurnal Cu will dissipate shortly, and should occur again tmrw
with similar synoptics. A slight uptick in dew points translates
to bases around 4-5K FT AGL tmrw. High level clouds may start to
advance upon the terminals late in the period as a front takes
shape and begins to approach from the north.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
718 PM EDT WED SEP 16 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM EDT WED SEP 16 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS THE UPPER GREAT LAKES
REGION BEING LOCATED BETWEEN AN UPPER RIDGE OVER THE EASTERN CONUS
AND AN UPPER TROUGH OVER THE WESTERN CONUS. THIS HAS LED TO
SOUTHWESTERLY FLOW ACROSS THE UPPER GREAT LAKES REGION AND THERE WAS
A WEAK SHORTWAVE THAT LIFTED NORTHEAST ACROSS THE AREA THIS MORNING.
THIS LED TO CLOUDS/SHOWERS AND EVEN A FEW THUNDERSTORMS OVER THE
WESTERN U.P. UNDER THE STEEP 700-300MB LAPSE RATES. THIS WAVE HAS
LIFTED TO THE NORTHEAST AND BROUGHT MUCH OF THE MID CLOUDS WITH
IT...ALTHOUGH THERE ARE STILL SOME LINGERING SHOWERS/SPRINKLES OVER
THE EAST AND NEAR DULUTH. THE THICKER MID CLOUDS DID HOLD OFF TEMPS
AND WINDS SOME THIS AFTERNOON BUT NOT THAT WE ARE SEEING MORE BREAKS
OVER THE WESTERN HALF OF THE CWA...TEMPERATURES HAVE RISEN INTO THE
UPPER 70S AND LOWER 80S. AS OF 3PM...NWS MARQUETTE IS JUST BELOW OUR
RECORD HIGH FOR TODAY (79) AND WOULD EXPECT THAT TO BE BROKEN IN THE
NEXT HOUR OR TWO. THE CLOUDS DID HELP LIMIT MIXING FROM REACHING THE
STRONGER WINDS ALOFT...BUT HAVE STILL BEEN SEEING 15-25KT WINDS OVER
MUCH OF THE AREA. EXPECT THE INCREASED SUNSHINE OVER THE NEXT COUPLE
HOURS TO LEAD TO SLIGHTLY HIGHER GUSTS THROUGH EARLY EVENING.
THE SURFACE LOW THAT IS CURRENTLY IN NORTHERN ONTARIO WILL CONTINUE
NORTHEAST THIS EVENING AND OVER NORTHERN JAMES BAY. THEN...ANOTHER
WAVE EJECTING NORTHEAST ACROSS EASTERN IDAHO WILL LEAD TO A
STRENGTHENING SURFACE LOW THAT IS CURRENTLY IN NORTHEAST WYOMING.
THIS LOW WILL LIFT NORTHEAST ACROSS THE DAKOTAS TONIGHT AND THEN
INTO NORTHERN ONTARIO ON THURSDAY. EXPECT PRECIPITATION CHANCES
TONIGHT INTO THURSDAY MORNING TO BE SIMILAR TO LAST NIGHT INTO THIS
MORNING WHERE THERE ARE STEEP 750-400MB LAPSE RATES IN PLACE AND
POCKETS OF MOISTURE OVER WESTERN LAKE SUPERIOR INTO FAR WESTERN
UPPER MICHIGAN. IN ADDITION...THERE IS A WEAK SHORTWAVE IN WESTERN
IOWA THAT LOOKS TO LIFT NORTHEAST THROUGH THE AREA. WITH THOSE
FEATURES BRUSHING THE WESTERN HALF OF THE CWA...WILL CONTINUE TO
SHOW SLIGHT CHANCE TO LOW END CHANCES FROM EAST TO WEST TOWARDS THE
MINNESOTA ARROWHEAD. WHILE THE DRY AIR BELOW 700MB WILL LIKELY LIMIT
THE MEASURABLE PRECIP IN SOME AREAS...FEEL THE SUPPORT IS THERE FOR
MEASURABLE RAIN TO OCCUR. ONCE AGAIN...EXPECT WINDS TO STAY UP
ACROSS THE AREA THROUGH THE NIGHT WITH THE STRONG LOW LEVEL JET (TO
45KTS) 2-3KFT ABOVE THE SURFACE. THOSE GUSTY WINDS WILL ALSO KEEP
TEMPERATURES WELL ABOVE THE NORMAL LOWS AND IN THE 60S WITH A FEW
70S OVER THE DOWNSLOPING AREAS OUT WEST.
HEADING INTO TOMORROW AFTERNOON...THE COLD FRONT TRAILING THE
SURFACE LOW LIFTING NORTHEAST FROM THE DAKOTAS INTO NORTHERN ONTARIO
THROUGH THE DAY WILL BE MOVING INTO WESTERN LAKE SUPERIOR DURING THE
LATE AFTERNOON AND EVENING HOURS. BELIEVE THE SHOWERS/THUNDERSTORMS
WILL BE LARGELY FOCUSED ALONG THE FRONT. BUT THERE ARE SOME HINTS AT
DEVELOPMENT OUT AHEAD OF THE FRONT AND TIED TO A SHORTWAVE LIFTING
NORTHEAST ACROSS THE WESTERN U.P. DURING THE AFTERNOON HOURS.
INSTABILITY WILL INCREASE OVER THE AREA WITH 1000-1500 J/KG OF
MLCAPE. BEST 0-6KM BULK SHEAR IS CONFINED TO THE AREAS IN IMMEDIATE
PROXIMITY OF THE FRONT...WITH THE REST OF THE AREA 20-25KT OUT AHEAD
OF THE FRONT. THAT WILL LEAD TO THE STRONGEST STORMS OCCURRING TO
THE WEST OF THE AREA IN THE AFTERNOON AND THEN TRYING TO SHIFT EAST
INTO THE U.P. DURING THE EVENING. WITH MORE CLOUD COVER
TOMORROW...HAVE LIMITED THE TEMPS TO THE UPPER 70S WITH A FEW LOWER
80S IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. WIND GUSTS WILL ALSO
BE SIMILAR BUT SLIGHTLY LOWER AND ONCE AGAIN HAVE GUSTS IN THE 20-
25KT RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM EDT WED SEP 16 2015
MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON POPS/SEVERE
WX POTENTIAL THU NGT ASSOCIATED WITH COLD FROPA THAT WL BRING A
RETURN OF COOLER WX LATE THIS WEEK. ANOTHER CONCERN WL BE POPS LATE
FRI INTO SAT RELATED TO THE APRCH OF ANOTHER SHRTWV AND ITS
INTERACTION WITH STALLING FNT IN THE CENTRAL GREAT LKS. HI PRES AND
NEAR SEASONABLE TEMPS WL THEN DOMINATE LATE THIS WEEKEND.
THU NGT INTO FRI...LATEST MODEL GUIDANCE IS IN GOOD AGREEMENT
SHOWING SFC COLD FNT CROSSING THE UPR LKS THU NGT PASSING NEWBERRY
SOON AFTER 12Z FRI AND INTERACTING WITH WARM AIRMASS/PWAT NEAR 1.75
INCHES. SINCE NAM/GFS SDNGS INDICATE THE PRE FRONTAL AIRMASS WL BE
CAPPED...THE BULK OF SHOWERS/TS THAT FORM UNDER H7-5 LAPSE RATES AS
STEEP AS 7.5-8C/KM ARE LIKELY TO BE CLOSER TO THE SFC FNT. FCST
MUCAPES AS HI AS 1000-1500 J/KG...DEEP LYR SHEAR ABOUT 30-35KTS
ALONG THE FRONTAL BNDRY AND FCST DCAPES AS HI AS ABOUT 1000 J/KG
FOLLOWING THE WARM DAY ON THU SUPPORT THE MARGINAL/SLGT RISK FOR SVR
STORMS OUTLOOK FM SPC. RELATIVELY HI FRZG LVL FCST IN THE 12-14K
RANGE AND DEEP SATURATION SHOWN ON ESPECIALLY THE NAM FCST SDNGS AS
WELL AS PASSAGE OF STRONGER SHRTWV/HGT FALLS FARTHER TO THE N CLOSER
TO THE MAIN SHRTWV TRACK IN FAR NW ONTARIO ARE NEGATIVES. BEST CHC
FOR THE STRONGER STORMS SHOULD BE OVER THE W...WHERE THE ARRIVAL OF
THE FNT IN THE EVNG WOULD BE MORE IN SYNC WITH THE DAYTIME HEATING
CYCLE/HIER DCAPES. THE ARRIVAL OF DRIER/COOLER AIR BEHIND THE FROPA
WL BRING A DRYING TREND W-E LATER THU NGT INTO FRI...BUT SHALLOW
LLVL MSTR WITH INFLUX OF COOLER AIR BEHIND THE FNT/LO INVRN MAY LEAD
TO LINGERING LO CLDS INTO FRI MRNG...ESPECIALLY IN THE UPSLOPE AREAS
NEAR LK SUP.
FRI/SAT...ARRIVAL OF DRIER AIR/WEAK HI PRES RDG AND LLVL ACYC FLOW
WL RESULT IN A PERIOD OF DRY WX ON FRI AFTER LINGERING SHOWERS END
IN THE MRNG OVER THE E. BUT APRCH OF SHRTWV FM THE W IN MORE ZONAL
FLOW IN THE NRN PLAINS IS FCST TO CAUSE A SFC LO PRES TO DVLP ON FRI
AFTN IN IOWA ALONG STALLING COLD FNT STRETCHING FM THAT STATE INTO
LOWER MI UNDER MORE SW FLOW ALF ON NW FLANK OF UPR RDG PERSISTING IN
THE ERN CONUS. SOME OF THE MEDIUM RANGE GUIDANCE HAD INDICATED A
BAND OF PCPN ASSOCIATED WITH AXIS OF MID LVL FGEN WOULD IMPACT AT
LEAST PORTIONS OF THE CWA ON FRI AFTN WELL TO THE NE OF THIS
FEATURE...BUT DRYNESS OF THE MID LVL AIRMASS SHOWN ON THE 12Z NAM/
GFS FCST SDNGS SUG A DRY FCST IS WARRANTED AFTER THE FROPA SHOWERS
END OVER THE E IN THE MRNG. THERE ARE CONSIDERABLE MODEL DIFFERENCES
ON HOW QUICKLY AND TO WHAT EXTENT THE SFC LO IN IOWA WL INTENSIFY AS
IT TRACKS NE ON THE STALLED FNT INTO THE CENTRAL LKS. THE 12Z NAM IS
DEEPEST AND FARTHER W WITH THE TRACK OF THIS SYSTEM...SHOWING
WIDESPREAD RA IMPACTING ALL OF UPR MI THRU THE DAY ON SAT WITH
FAIRLY SHARP CYC NE FLOW LEADING TO A VERY CHILLY DAY AS WELL. THE
00Z CNDN/ECMWF RUNS ON THE OTHER HAND SHOWED A RELATIVELY WEAK SFC
LO MOVING QUICKLY TO THE NE...WITH LIGHTER PCPN ENDING SOON AFTER
12Z SAT. ALTHOUGH THE INCOMING SHRTWV IS RATHER IMPRESSIVE...WITH
00Z-12Z SAT H5 HGT FALLS FCST UP TO 100M EVEN WITH THE WEAKER ECWMF
FCST...AND MODEL TRENDS SUPPORT THE NAM FCST...PREFER TO FOLLOW A
COMPROMISE BTWN THE SOMEWHAT DEEPER 12Z GFS/CNDN/ECMWF MODEL FCSTS
AND THE WEAKER/FASTER SCENARIO SHOWN BY THE 00Z ECMWF/CNDN AND 09Z
SREF. NCEP GUIDANCE ALSO INDICATES A PREFERENCE FOR REJECTING THE
DEEPER 12Z NAM FCST. THE PREFERRED MODELS SHOW THE HIER CATEGORICAL/
LIKELY POPS OVER ALL BUT THE WRN CWA...WHERE CHC POPS APPEAR MORE
APPROPRIATE FARTHEST FM THE STALLED BNDRY TO THE SE. THIS SCENARIO
WL ALSO SUPPORT A STEADY DRYING TREND W-E ON SAT...WITH PCPN ENDING
OVER THE FAR E BY EARLY/MID AFTN.
SAT NGT INTO TUE...HI PRES TRAILING THE DEPARTING SFC LO PRES IS
FCST TO BUILD INTO THE LOWER GREAT LKS BY 12Z SUN...THE NE STATES AT
12Z MON AND THEN OVER THE CNDN MARITIMES ON TUE. DRY ACYC SW FLOW
ARND THIS FEATURE WL DOMINATE UPR MI DURING THIS TIME AND BRING A
PERIOD OF DRY WX. ALTHOUGH PWAT FALLING TOWARD 0.5 INCH AT 12Z SUN
WOULD SUPPORT SOME CHILLY OVERNGT LOWS...STEADY WSW FLOW ON THE NRN
FLANK OF HI PRES CENTER TO THE S MAY TEND TO LIMIT THE POTENTIAL FOR
COLDER TEMPS/FROST...ESPECIALLY OVER THE NW HALF UNDER TIGHTER PRES
GRADIENT. H85 TEMPS ARE FCST TO SLOWLY MODERATE THRU THIS TIME...
RISING FM ARND 8C ON SUN TO ARND 10C ON MON AND THEN 12C ON TUE...
SUPPORTING A SLOW WARMING TREND THAT WL FEATURE MEAN DAILY TEMPS
RISING FM NEAR NORMAL ON SUN TO AT LEAST A BIT ABOVE NORMAL AGAIN ON
MON/TUE.
TUE/WED...SHRTWV MOVING THRU ZONAL FLOW OVER CENTRAL CANADA IS FCST
TO DRAG A COLD FNT THRU THE UPR LKS LATE TUE/TUE NGT. SINCE THERE
ARE TIMING DIFFERENCES AND THE LONGER RANGE GUIDANCE HINTS MSTR
INFLOW WL BE SOMEWHAT LIMITED TO THE S OF SHARPER HGT FALLS TO THE
N...NO MORE THAN LO CHC POPS ARE NECESSARY AT THIS POINT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 717 PM EDT WED SEP 16 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH GUSTY
SOUTH-SOUTHWESTERLY WINDS. THE GUSTY WINDS WILL WEAKEN SLIGHTLY
TONIGHT AND LEAD TO THE POTENTIAL FOR LLWS AT ALL THREE SITES.
THOUGH KSAW/KIWD WOULD HAVE THE BEST CHANCE FOR THE WINDS TO STAY
UP AND HAVE LEFT LLWS OUT AT THOSE SITES. A DISTURBANCE WILL PUSH
ACROSS WESTERN LAKE SUPERIOR LATE TONIGHT AND IT COULD BRUSH KIWD.
THEN...SHOWERS WILL INCREASE FROM WEST TO EAST DURING THE AFTERNOON
AND EVENING AS A COLD FRONT SWEEPS ACROSS THE AREA. EXPECT
DETERIORATING CONDITIONS TO MVFR CIGS FOR SAW AND IWD LATE IN THE
AFTERNOON AND MVFR CIGS WILL BE CLOSE TO CMX AT THAT TIME AS WELL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 306 PM EDT WED SEP 16 2015
GUSTY SOUTHERLY WINDS WILL REMAIN IN PLACE OVER THE NEXT 24-30
HOURS AS THE UPPER GREAT LAKES REGION IS BETWEEN HIGH PRESSURE IN
THE MID ATLANTIC STATES AND A COUPLE LOWS THAT WILL BE MOVING
NORTHEAST ACROSS ONTARIO. THESE SOUTHERLY WINDS WILL GENERALLY BE
IN THE 15-25KT RANGE...BUT WITH VERY STRONG WINDS JUST ABOVE THE
SURFACE...COULD SEE SOME STRONGER GUSTS TO 30KTS AT TIMES OVER
EASTERN LAKE SUPERIOR. A COLD FRONT MOVING EAST ACROSS LAKE
SUPERIOR ON THURSDAY NIGHT WILL SHIFT WINDS TO THE NORTHWEST UP TO
25KTS. THE WINDS WILL DIMINISH THROUGH THE DAY ON FRIDAY AS A HIGH
PRESSURE RIDGE QUICKLY BUILDS INTO THE AREA. ON FRIDAY NIGHT...A
SURFACE LOW WILL DEVELOP ALONG THE COLD FRONT THAT MOVED THROUGH ON
THURSDAY NIGHT AND MOVE THROUGH LOWER MICHIGAN. THIS WILL SHIFT
WINDS MORE OUT OF THE NORTHERLY DIRECTION UP TO 25 KNOTS LATE
FRIDAY NIGHT INTO SATURDAY MORNING. A LARGE HIGH PRESSURE RIDGE
WILL BUILD OVER THE GREAT LAKES REGION SATURDAY NIGHT AND REMAIN
INTO MONDAY AND KEEP WINDS BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...07
MARINE...SRF
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 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 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
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 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 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
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 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 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:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
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 WILMINGTON NC
949 PM EDT WED SEP 16 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED JUST TO OUR NORTH WILL WEAKEN GRADUALLY AS
THE WEEK PROGRESSES. HUMIDITY LEVELS WILL CREEP HIGHER AND CLOUDS
WILL INCREASE...BRINGING A RISK FOR SHOWERS...MAINLY ALONG THE
IMMEDIATE COAST THURSDAY THROUGH EARLY SATURDAY. A COLD FRONT
WILL DROP INTO AND SOUTH OF THE AREA BY EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 945 PM WEDNESDAY...SFC HIGH CENTERED OVER LAND...THE VA
CAPES ATTM...AND WILL CONTINUE TO FUNNEL RELATIVELY DRY AIR ACROSS
THE FA AT THE LOW LEVELS...WITH MUCH OF IT FELT ACROSS THE ILM NC
CWA. THIS HAS KEPT THE LOW AND MID LEVELS RELATIVELY DRY WITH ONLY
CI/CS...OCCASIONALLY OPAQUE...PUSHING ACROSS THE ENTIRE ILM CWA.
LATEST VARIOUS MODEL TIME HEIGHT DISPLAYS ACROSS THE FA SUPPORT
THIS OCCURRING THRU THE EVENING AND OVERNIGHT. THE FLY IN THE
OINTMENT...IS THE TROFFINESS IN THE MID AND UPPER LEVELS ACROSS
THE NE GULF OF MEXICO EXTENDING INTO THE SOUTHEAST UNITED STATES.
MODELS DO INDICATE THIS FEATURE DRIFTING TOWARD THE NE- ENE
OVERNIGHT. THIS WILL RESULT IN SOME SHARPENING OF THE INVERTED SFC
TROF OFF THE SOUTHEAST U.S. COAST OVERNIGHT INTO THE SHORT TERM
PERIOD. IN ADDITION...LOOK FOR MOISTURE TO INCREASE AT ALL LEVELS
MAINLY ACROSS THE ILM SC CWA...MAINLY WELL SOUTH AND EAST OF THE
I-95 CORRIDOR TO THE SC COAST. HAVE CONCENTRATED THE INCREASE IN
POPS MAINLY ACROSS THE COASTAL COUNTIES OF THE ILM SC CWA...AND
MAINLY AFTER MIDNIGHT. THE LATEST RAP MODEL RUN HOLDS OFF THE
DEEPER MOISTURE FROM REACHING THE ILM NC COASTAL CWA OVERNIGHT.
HAVE BASICALLY KEPT A DRY BIAS ACROSS THE ILM NC CWA...WITH ONLY
AN ISOLATED -SHRA POSSIBLE ALONG THE IMMEDIATE NC COAST FROM
ROUGHLY CAPE FEAR SOUTHWARD OCCURRING AROUND DAYBREAK THU. SOME
MASSAGING OF THE MIN TEMPS...SLIGHTLY LOWER BY A DEGREE OR 2
MAINLY ACROSS THE ILM NC CWA...AND ACROSS THE NW PORTIONS OF THE
ILM SC CWA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A COASTAL TROUGH OR PERHAPS EVEN A VERY
MEEKLY CLOSED OFF WILL VERY SLOWLY TAKE SHAPE OVER THE COURSE OF THE
SHORT TERM PERIOD. THERE WILL ALSO BE A TROUGHINESS IN THE MID
LEVELS RUNNING FROM THE FL BIG BEND TO THE OUTER BANKS OF NC.
TOGETHER THESE WILL CHANNEL FAIRLY DEEP MOISTURE UP THE COAST.
MODELS ARE HAVING DIFFICULTY RESOLVING THE WESTWARD EXTENT OF THE
MOISTURE AND THUS RAIN CHANCES. ADVECTING PRECIPITATION TOO FAR AND
TOO FAST IS A COMMON MODEL ERROR SO THE HIGH POPS AND QPF OF THE GFS
HAVE BEEN DOWNPLAYED IN FAVOR OF THE MUCH MORE CONSERVATIVE ECMWF.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SATURDAY WILL BEGIN WITH A TROUGH SFC-
ALOFT MOVING SLOWLY EASTWARD ACROSS SC-GA-FL. THE TROUGH WILL SLOW
BY SUNDAY AND LINGER OFF THE SOUTHEAST CONUS INTO TUESDAY. THERE
WILL GOOD POTENTIAL FOR SHOWERS TO AFFECT THE CWA SATURDAY AS DEEP
MOISTURE CIRCULATES ONSHORE AND PRECIPITABLE WATER VALUES EXCEED
TWO INCHES ACROSS THE EASTERN HALF OF THE CWA. THE MOISTURE
GRADIENT WILL BE SOMEWHAT TIGHT HOWEVER...SO IF THE TROUGH REMAINS
FAR ENOUGH OFFSHORE...PRECIP CHANCES WOULD BE SIGNIFICANTLY LOWER.
FOR SUNDAY-WEDNESDAY...THE FORECAST UNCERTAINTY INCREASES AS THE
GFS AND ECMWF DIFFER ON HOW THIS TROUGH WILL INTERACT WITH ANOTHER
SHARP TROUGH APPROACHING FROM THE WEST. THOUGH BOTH MODELS BRING
DRIER MID-LEVEL AIR ACROSS THE AREA ON SUNDAY...THE ECMWF DRAWS
THE TROUGH AND ASSOCIATED MOISTURE WESTWARD EARLY NEXT WEEK WHILE
THE GFS KEEPS IT FURTHER OFFSHORE. DUE TO THIS UNCERTAINTY...PLAN
TO INCLUDE AT LEAST A SMALL POP EACH DAY EXCEPT SUNDAY.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...A COASTAL TROUGH WILL SLOWLY MOVE NORTHWARD OVER THE
COURSE OF THE NEXT 24 HOURS. LOOK FOR MAINLY A MID CLOUD CEILING
OVERNIGHT...INTERMITTENTLY A VFR STRATOCU CEILING. THE TIME HEIGHT
SHOWS CEILINGS SLOWLY LOWERING OVERNIGHT...WITH A 4K DECK OVER MUCH
OF THE COAST BY MORNING. THINK THERE WILL BE ENOUGH ONSHORE MOISTURE
TO PRODUCE WEAK SHOWERS AT THE MYRTLES. THE PRECIP MAY MAKE IT AS
FAR NORTH AS ILM...HOWEVER HAVE ONLY ADDED VCSH AT THIS TIME DUE
TO FAIRLY LOW CONFIDENCE. INLAND TERMINALS WILL REMAIN VFR WITH
NO PRECIP EXPECTED THROUGH THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...COASTAL SHOWERS ARE POSSIBLE THROUGH SATURDAY
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM WEDNESDAY...SFC HIGH TO REMAIN CENTERED ACROSS THE
VA CAPES THIS EVENING AND OVERNIGHT...AND WILL RIDGE SW ACROSS THE
CENTRAL CAROLINAS INTO DAYTIME THU. AT THE SAME TIME...AN
INVERTED SFC TROF WILL FURTHER DEVELOP AND EXTEND NE ACROSS THE
OFFSHORE WATERS OFF THE CAROLINAS...NEARLY PARALLEL TO THE
CAROLINAS COASTLINES. SOME MODELS INDICATE A TIGHTENING OF THE SFC
PG IN THE VICINITY OF THE ILM SC WATERS AND THUS WILL GO AHEAD AND
INDICATE A SOLID 15 KT...TO POSSIBLY 20 KT ACROSS THE
SOUTHERNMOST PORTIONS OF THE ILM COASTAL WATERS.
SIGNIFICANT SEAS WILL RUN AROUND 3 FT FOR THE ILM NC WATERS...AND
POSSIBLY BUILD TO A SOLID 4 FT FOR THE SOUTHERNMOST ILM SC WATERS
DURING THE OVERNIGHT. WITH THIS PERSISTENT ONSHORE FLOW...A
SEMI-GROUND SWELL SO TO SPEAK...WILL AFFECT THE AREA WATERS
RUNNING AT 6 TO 7 SECOND PERIODS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...THE LARGE AREA OF HIGH PRESSURE THAT HAS
BEEN BRINGING NORTHEASTERLY WINDS FOR A WHILE NOW WILL GRADUALLY
WEAKEN AND DRIFT EASTWARD THROUGH THE PERIOD. MEANWHILE AN UPPER
LEVEL TROUGH LINING UP ALONG THE COAST WILL INDUCE A SURFACE WAVE
OF LOW PRESSURE THAT MAY EVEN TRY TO FORM A WEAKLY CLOSED LOW.
THIS TROUGHINESS WILL OFFSET THE WEAKENING OF THE HIGH TO KEEP
WIND SPEEDS FAIRLY STEADY IN THE 10-15KT RANGE OVER MOST ZONES AND
SOME GUSTS TO 20 ARE POSSIBLE LATE IN THE PERIOD AS LOW LEVEL
JETTING INCREASES SOME. A FEW 4 FT SEAS MAY APPEAR ALONG THE
EASTWARD EXTREME OF SOME OF THE MARINE ZONES.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...SURFACE LOW PRESSURE IS EXPECTED TO
DEVELOP OFF THE SOUTH CAROLINA COAST SATURDAY AND LINGER OFF THE
SOUTHEAST COAST OF THE CONUS THROUGH MONDAY. GIVEN THE PROXIMITY
OF THE LOW...THE AREA WATERS SHOULD REMAIN IN A GENERAL NORTHEAST
FLOW IN THE 15-20 KNOT RANGE. EXPECT SEAS OF 3-4 FEET THROUGH THE
PERIOD...CLOSER TO 2 FEET IN THE SHELTERED WATERS SOUTH OF CAPE
FEAR...BUT WINDS AND SEAS LOOK TO TREND HIGHER SUNDAY NIGHT AND
MONDAY AS HIGH PRESSURE BUILDS OVER THE CAROLINAS AND THE PRESSURE
GRADIENT INTENSIFIES OVER THE WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...CRM
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
751 PM EDT WED SEP 16 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED JUST TO OUR NORTH WILL WEAKEN GRADUALLY AS
THE WEEK PROGRESSES. HUMIDITY LEVELS WILL CREEP HIGHER AND CLOUDS
WILL INCREASE...BRINGING A RISK FOR SHOWERS...MAINLY ALONG THE
IMMEDIATE COAST THURSDAY THROUGH EARLY SATURDAY. A COLD FRONT
WILL DROP INTO AND SOUTH OF THE AREA BY EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 645 PM WEDNESDAY...SFC HIGH CENTERED STILL OVER LAND...THE
VA CAPES ATTM...WILL CONTINUE TO FUNNEL RELATIVELY DRY AIR ACROSS
THE FA...WITH MUCH OF IT FELT ACROSS THE ILM NC CWA. THIS HAS KEPT
THE LOW AND MID LEVELS RELATIVELY DRY WITH ONLY CI/CS
OCCASIONALLY OPAQUE PUSHING ACROSS THE ENTIRE ILM CWA. LATEST
VARIOUS MODEL TIME HEIGHT DISPLAYS ACROSS THE FA SUPPORT THIS
OCCURRING THRU THE EVENING AND OVERNIGHT. THE FLY IN THE
OINTMENT...IS THE TROFFINESS IN THE MID AND UPPER LEVELS ACROSS
THE NE GULF OF MEXICO EXTENDING INTO THE SOUTHEAST UNITES STATES.
MODELS DO INDICATE THIS FEATURE DRIFTING TOWARD THE NE-ENE
OVERNIGHT. THIS WILL RESULT IN SOME SHARPENING OF THE INVERTED SFC
TROF OFF THE SOUTHEAST U.S. COAST OVERNIGHT INTO THE SHORT TERM
PERIOD. IN ADDITION...LOOK FOR MOISTURE TO INCREASE AT ALL LEVELS
MAINLY ACROSS THE ILM SC CWA...MAINLY WELL SOUTH AND EAST OF THE
I-95 CORRIDOR TO THE SC COAST. HAVE CONCENTRATED THE INCREASE IN
POPS MAINLY ACROSS THE COASTAL COUNTIES OF THE ILM SC CWA...AND
MAINLY AFTER MIDNIGHT. THE LATEST RAP MODEL RUN HOLDS OFF THE
DEEPER MOISTURE FROM REACHING THE ILM NC COASTAL CWA OVERNIGHT.
HAVE BASICALLY KEPT A DRY BIAS ACROSS THE ILM NC CWA...WITH ONLY
AN ISOLATED -SHRA POSSIBLE ALONG THE IMMEDIATE NC COAST MAINLY
FROM CAPE FEAR SOUTHWARD AROUND DAYBREAK THU. SOME MASSAGING OF
THE MIN TEMPS...SLIGHTLY LOWER BY A DEGREE OR 2 MAINLY ACROSS THE
ILM NC CWA...AND ACROSS THE NW PORTIONS OF THE ILM SC CWA.
PREVIOUS.......................................................
AS OF 3 PM WEDNESDAY...A LARGE AND WEAKENING AREA OF HIGH
PRESSURE WILL BE TO OUR NORTH THROUGH THE PERIOD. SATELLITE
IMAGERY DEPICTS AN UPPER LEVEL DISTURBANCE OVER THE GULF STATES
FLINGING GOMEX MOISTURE ACROSS THE SOUTHEAST. AS THIS FEATURE
BEGINS TO MOVE NORTHEASTWARD OVERNIGHT THE MOISTURE SHOULD
INCREASE. THIS WILL MAINLY MANIFEST IN THE FORM OF INCREASING
CLOUD COVER. A DEVELOPING SURFACE AND LOW LEVEL TROUGH COULD BRING
ENOUGH LIFT FOR SOME OF THE RADAR RETURNS NEAR SAVANNA TO CREEP UP
THE COAST MAINLY AFTER MIDNIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A COASTAL TROUGH OR PERHAPS EVEN A VERY
MEEKLY CLOSED OFF WILL VERY SLOWLY TAKE SHAPE OVER THE COURSE OF THE
SHORT TERM PERIOD. THERE WILL ALSO BE A TROUGHINESS IN THE MID
LEVELS RUNNING FROM THE FL BIG BEND TO THE OUTER BANKS OF NC.
TOGETHER THESE WILL CHANNEL FAIRLY DEEP MOISTURE UP THE COAST.
MODELS ARE HAVING DIFFICULTY RESOLVING THE WESTWARD EXTENT OF THE
MOISTURE AND THUS RAIN CHANCES. ADVECTING PRECIPITATION TOO FAR AND
TOO FAST IS A COMMON MODEL ERROR SO THE HIGH POPS AND QPF OF THE GFS
HAVE BEEN DOWNPLAYED IN FAVOR OF THE MUCH MORE CONSERVATIVE ECMWF.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SATURDAY WILL BEGIN WITH A TROUGH SFC-
ALOFT MOVING SLOWLY EASTWARD ACROSS SC-GA-FL. THE TROUGH WILL SLOW
BY SUNDAY AND LINGER OFF THE SOUTHEAST CONUS INTO TUESDAY. THERE
WILL GOOD POTENTIAL FOR SHOWERS TO AFFECT THE CWA SATURDAY AS DEEP
MOISTURE CIRCULATES ONSHORE AND PRECIPITABLE WATER VALUES EXCEED
TWO INCHES ACROSS THE EASTERN HALF OF THE CWA. THE MOISTURE
GRADIENT WILL BE SOMEWHAT TIGHT HOWEVER...SO IF THE TROUGH REMAINS
FAR ENOUGH OFFSHORE...PRECIP CHANCES WOULD BE SIGNIFICANTLY LOWER.
FOR SUNDAY-WEDNESDAY...THE FORECAST UNCERTAINTY INCREASES AS THE
GFS AND ECMWF DIFFER ON HOW THIS TROUGH WILL INTERACT WITH ANOTHER
SHARP TROUGH APPROACHING FROM THE WEST. THOUGH BOTH MODELS BRING
DRIER MID-LEVEL AIR ACROSS THE AREA ON SUNDAY...THE ECMWF DRAWS
THE TROUGH AND ASSOCIATED MOISTURE WESTWARD EARLY NEXT WEEK WHILE
THE GFS KEEPS IT FURTHER OFFSHORE. DUE TO THIS UNCERTAINTY...PLAN
TO INCLUDE AT LEAST A SMALL POP EACH DAY EXCEPT SUNDAY.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...A COASTAL TROUGH WILL SLOWLY MOVE NORTHWARD OVER THE
COURSE OF THE NEXT 24 HOURS. LOOK FOR MAINLY A MID CLOUD CEILING
OVERNIGHT...INTERMITTENTLY A VFR STRATOCU CEILING. THE TIME HEIGHT
SHOWS CEILINGS SLOWLY LOWERING OVERNIGHT...WITH A 4K DECK OVER MUCH
OF THE COAST BY MORNING. THINK THERE WILL BE ENOUGH ONSHORE MOISTURE
TO PRODUCE WEAK SHOWERS AT THE MYRTLES. THE PRECIP MAY MAKE IT AS
FAR NORTH AS ILM...HOWEVER HAVE ONLY ADDED VCSH AT THIS TIME DUE
TO FAIRLY LOW CONFIDENCE. INLAND TERMINALS WILL REMAIN VFR WITH
NO PRECIP EXPECTED THROUGH THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...COASTAL SHOWERS ARE POSSIBLE THROUGH SATURDAY
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 PM WEDNESDAY...SFC HIGH TO REMAIN CENTERED ACROSS THE VA
CAPES THIS EVENING AND OVERNIGHT...AND WILL RIDGE SW ACROSS THE
CENTRAL CAROLINAS OVERNIGHT INTO DAYTIME THU. AT THE SAME
TIME...AN INVERTED SFC TROF WILL FURTHER DEVELOP AND EXTEND NE
ACROSS THE OFFSHORE WATERS OFF THE CAROLINAS...NEARLY PARALLEL TO
THE CAROLINAS COASTLINES. SOME MODELS INDICATE A TIGHTENING OF THE
SFC PG IN THE VICINITY OF THE ILM SC WATERS AND THUS WILL GO AHEAD
AND INDICATE A SOLID 15 KT TO POSSIBLY 20 KT ACROSS THE
SOUTHERNMOST PORTIONS OF THE ILM COASTAL WATERS.
SIGNIFICANT SEAS WILL RUN AROUND 3 FT FOR THE ILM NC WATERS...AND
POSSIBLY BUILD TO A SOLID 4 FT FOR THE SOUTHERNMOST ILM SC WATERS
DURING THE OVERNIGHT. WITH THIS PERSISTENT ONSHORE FLOW...A
SEMI-GROUND SWELL...SO TO SPEAK...WILL AFFECT THE AREA WATERS
RUNNING AT 6 TO 7 SECOND PERIODS.
PREVIOUS.......................................................
AS OF 3 PM WEDNESDAY...THIS IS MAINLY A FORECAST OF PERSISTENCE AS
LARGE AREA OF HIGH PRESSURE REMAINS TO OUR NORTH. LOCALLY THIS HAS
BEEN AND WILL CONTINUE TO BRING NE TO EASTERLY FLOW. A SLIGHT
WEAKENING TREND IN THE HIGH PRESSURE MAY SHAVE OFF A FEW KNOTS OF
WINDSPEED OVERNIGHT OR AT LEAST CAUSE THE GUSTINESS TO ABATE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...THE LARGE AREA OF HIGH PRESSURE THAT HAS
BEEN BRINGING NORTHEASTERLY WINDS FOR A WHILE NOW WILL GRADUALLY
WEAKEN AND DRIFT EASTWARD THROUGH THE PERIOD. MEANWHILE AN UPPER
LEVEL TROUGH LINING UP ALONG THE COAST WILL INDUCE A SURFACE WAVE OF
LOW PRESSURE THAT MAY EVEN TRY TO FORM A WEAKLY CLOSED LOW. THIS
TROUGHINESS WILL OFFSET THE WEAKENING OF THE HIGH TO KEEP WIND
SPEEDS FAIRLY STEADY IN THE 10-15KT RANGE OVER MOST ZONES AND SOME
GUSTS TO 20 ARE POSSIBLE LATE IN THE PERIOD AS LOW LEVEL JETTING
INCREASES SOME. A FEW 4 FT SEAS MAY APPEAR ALONG THE EASTWARD
EXTREME OF SOME OF THE MARINE ZONES.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...SURFACE LOW PRESSURE IS EXPECTED TO
DEVELOP OFF THE SOUTH CAROLINA COAST SATURDAY AND LINGER OFF THE
SOUTHEAST COAST OF THE CONUS THROUGH MONDAY. GIVEN THE PROXIMITY
OF THE LOW...THE AREA WATERS SHOULD REMAIN IN A GENERAL NORTHEAST
FLOW IN THE 15-20 KNOT RANGE. EXPECT SEAS OF 3-4 FEET THROUGH THE
PERIOD...CLOSER TO 2 FEET IN THE SHELTERED WATERS SOUTH OF CAPE
FEAR...BUT WINDS AND SEAS LOOK TO TREND HIGHER SUNDAY NIGHT AND
MONDAY AS HIGH PRESSURE BUILDS OVER THE CAROLINAS AND THE PRESSURE
GRADIENT INTENSIFIES OVER THE WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH/TRA
SHORT TERM...MBB
LONG TERM...CRM
AVIATION...DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1039 PM CDT WED SEP 16 2015
.UPDATE...
ISSUED AT 1027 PM CDT WED SEP 16 2015
AS OF 330 UTC...ELEVATED CONVECTION ASSOCIATED WITH A WARM FRONT
ACROSS THE I-94 CORRIDOR IN A LOW CAPE...HIGH SHEAR ENVIRONMENT
HAS DISPLAYED LOW-TOPPED SUPERCELLULAR CHARACTERISTICS OVER THE
PAST 1-2 HOURS. THIS INCLUDES THE STORM THAT IMPACTED THE
DICKINSON AREA EARLIER THIS EVENING. THUS...EXPECT A MARGINAL
THREAT FOR SEVERE HAIL AND WIND GUSTS TO PERSIST THROUGH 06-07
UTC ACROSS THE I-94 THROUGH ND HIGHWAY 200 CORRIDORS.
UPDATE ISSUED AT 651 PM CDT WED SEP 16 2015
NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE AS A TIME LAGGED
ENSEMBLE OF THE 21-23 UTC HRRR ITERATIONS MATCHES WELL WITH
ONGOING RADAR TRENDS THROUGH 00 UTC AHEAD OF MULTIPLE SHORTWAVES
ACROSS EASTERN MONTANA INTO NORTHWEST SOUTH DAKOTA. GIVEN WEAK
INSTABILITY...THE PREDOMINANT MODE OF PRECIPITATION IS EXPECTED TO
BE RAIN SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. SEVERE WEATHER
IS NOT EXPECTED.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 216 PM CDT WED SEP 16 2015
A STRONG UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TO WESTERN AND CENTRAL NORTH DAKOTA TONIGHT.
FOLLOWED BY COOLER TEMPERATURES AND BREEZY CONDITIONS ON THURSDAY.
CURRENTLY...SHORTWAVE TROUGH FROM CENTRAL MONTANA INTO WESTERN
WYOMING IS LIFTING NORTHEAST THROUGH THE WESTERN U.S. UPPER LEVEL
LONGWAVE TROUGH. LEADING EDGE OF SHOWER ACTIVITY EXTENDS TO AROUND
WOLF POINT AND MILES CITY IN EASTERN MONTANA. SURFACE LOW PRESSURE
WAS SITUATED OVER NORTHEAST WYOMING WITH AND INCREASING SOUTHEAST
SURFACE FLOW OVER SOUTHWEST NORTH DAKOTA...AND AN INCREASING EAST
TO NORTHEAST SURFACE FLOW ELSEWHERE.
LATE THIS AFTERNOON AND TONIGHT. EXPECT SHOWER AND THUNDERSTORM
ACTIVITY TO INCREASE OVER EASTERN MONTANA AND WESTERN NORTH
DAKOTA LATE THIS AFTERNOON AS THE SURFACE LOW TRACKS INTO
NORTHWEST NORTH DAKOTA. THERE IS SOME WEAK INSTABILITY ALOFT LATE
THIS AFTERNOON INTO EARLY THIS EVENING OVER WESTERN NORTH DAKOTA.
BUT LOW LEVEL INHIBITION REMAINS STRONG. WE DO SEE INCREASING
LAPSE RATES LATER THIS AFTERNOON AND WITH THE STRONG DYNAMIC WAVE
LIFTING THROUGH THE AREA...AN ISOLATED SEVERE WIND GUST COULD BE
POSSIBLE. BUT GENERALLY THINK SCATTERED TO NUMEROUS SHOWERS AND
EMBEDDED THUNDERSTORMS LIFTING FROM WESTERN INTO NORTH CENTRAL
NORTH DAKOTA ALONG AND NORTH OF THE SURFACE LOW THAT TRACKS ACROSS
THE NORTH DAKOTA/SOUTH DAKOTA BORDER.
ON THURSDAY...SCATTERED SHOWERS WILL REMAIN ALONG THE
INTERNATIONAL BORDER...CLOSER TO THE COLD AIR ASSOCIATED WITH THE
UPPER LEVEL TROUGH. FARTHER SOUTH...PERHAPS A LINGERING SHOWER
ACROSS THE SOUTH CENTRAL...BUT EXPECT INCREASING SUBSIDENCE
THROUGH THE DAY WITH HIGH PRESSURE BUILDING OVER THE AREA. BREEZY
CONDITIONS DURING THE MORNING AND EARLY AFTERNOON WITH DIMINISHING
WINDS MID TO LATE AFTERNOON AS THE SURFACE HIGH BUILDS OVER THE
STATE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 216 PM CDT WED SEP 16 2015
SHOWERS AND THUNDERSTORMS HIGHLIGHT THE FORECAST FOR THURSDAY
NIGHT AND FRIDAY...WHILE DRY AND SEASONABLE CONDITIONS BECOME THE
FOCUS FOR THE WEEKEND.
THURSDAY NIGHT...A DEPARTING SHORTWAVE WILL KEEP AN ISOLATED SHOWER
OR TWO POSSIBLE IN THE NORTHEAST PART OF THE COUNTY WARNING AREA...
WITH A BRIEF PERIOD OF CLEARING ACROSS THE STATE FROM WEST TO EAST.
EARLY FRIDAY MORNING...THE NEXT SHORTWAVE WILL MOVE INTO SOUTH
DAKOTA FROM WYOMING...INCREASING CLOUD COVER AND PRECIPITATION
CHANCES OVER OUR SOUTHERN ZONES. 12Z NAM/GFS MODEL RUNS SUGGEST THE
BEST CHANCES FOR SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM WILL
RESIDE OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA...MAINLY ALONG
AND SOUTH OF INTERSTATE 94 FRIDAY MORNING AND INTO THE EARLY
AFTERNOON. MEAGER INSTABILITY FROM MODEL FORECAST SOUNDINGS SHOULD
KEEP THUNDERSTORM COVERAGE AND STRENGTH TO A MINIMUM. HIGH
TEMPERATURES ON FRIDAY WILL REMAIN ON THE COOL SIDE...GENERALLY IN
THE 60S.
SATURDAY WILL FEATURE DRY AND SEASONABLE CONDITIONS WITH HIGHS IN
THE LOWER 70S. PLEASANT WEATHER WILL CONTINUE THROUGH MONDAY...WITH
TEMPERATURES WARMING SLIGHTLY EACH DAY. THE NEXT CHANCES FOR
PRECIPITATION WILL BE OVERNIGHT MONDAY AND INTO TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1027 PM CDT WED SEP 16 2015
SCATTERED TO NUMEROUS RAIN SHOWERS WITH A FEW THUNDERSTORMS WILL
MOVE ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS EVENING AND
TONIGHT. CEILINGS ARE EXPECTED TO LOWER TO MVFR AT KISN/KDIK/KMOT
TONIGHT. KJMS AND KBIS ARE MORE UNCERTAIN REGARDING POTENTIAL
STRATUS IMPACTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...ZH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
704 PM CDT WED SEP 16 2015
.UPDATE...
ISSUED AT 651 PM CDT WED SEP 16 2015
NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE AS A TIME LAGGED
ENSEMBLE OF THE 21-23 UTC HRRR ITERATIONS MATCHES WELL WITH
ONGOING RADAR TRENDS THROUGH 00 UTC AHEAD OF MULTIPLE SHORTWAVES
ACROSS EASTERN MONTANA INTO NORTHWEST SOUTH DAKOTA. GIVEN WEAK
INSTABILITY...THE PREDOMINANT MODE OF PRECIPITATION IS EXPECTED TO
BE RAIN SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. SEVERE WEATHER
IS NOT EXPECTED.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 216 PM CDT WED SEP 16 2015
A STRONG UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TO WESTERN AND CENTRAL NORTH DAKOTA TONIGHT.
FOLLOWED BY COOLER TEMPERATURES AND BREEZY CONDITIONS ON THURSDAY.
CURRENTLY...SHORTWAVE TROUGH FROM CENTRAL MONTANA INTO WESTERN
WYOMING IS LIFTING NORTHEAST THROUGH THE WESTERN U.S. UPPER LEVEL
LONGWAVE TROUGH. LEADING EDGE OF SHOWER ACTIVITY EXTENDS TO AROUND
WOLF POINT AND MILES CITY IN EASTERN MONTANA. SURFACE LOW PRESSURE
WAS SITUATED OVER NORTHEAST WYOMING WITH AND INCREASING SOUTHEAST
SURFACE FLOW OVER SOUTHWEST NORTH DAKOTA...AND AN INCREASING EAST
TO NORTHEAST SURFACE FLOW ELSEWHERE.
LATE THIS AFTERNOON AND TONIGHT. EXPECT SHOWER AND THUNDERSTORM
ACTIVITY TO INCREASE OVER EASTERN MONTANA AND WESTERN NORTH
DAKOTA LATE THIS AFTERNOON AS THE SURFACE LOW TRACKS INTO
NORTHWEST NORTH DAKOTA. THERE IS SOME WEAK INSTABILITY ALOFT LATE
THIS AFTERNOON INTO EARLY THIS EVENING OVER WESTERN NORTH DAKOTA.
BUT LOW LEVEL INHIBITION REMAINS STRONG. WE DO SEE INCREASING
LAPSE RATES LATER THIS AFTERNOON AND WITH THE STRONG DYNAMIC WAVE
LIFTING THROUGH THE AREA...AN ISOLATED SEVERE WIND GUST COULD BE
POSSIBLE. BUT GENERALLY THINK SCATTERED TO NUMEROUS SHOWERS AND
EMBEDDED THUNDERSTORMS LIFTING FROM WESTERN INTO NORTH CENTRAL
NORTH DAKOTA ALONG AND NORTH OF THE SURFACE LOW THAT TRACKS ACROSS
THE NORTH DAKOTA/SOUTH DAKOTA BORDER.
ON THURSDAY...SCATTERED SHOWERS WILL REMAIN ALONG THE
INTERNATIONAL BORDER...CLOSER TO THE COLD AIR ASSOCIATED WITH THE
UPPER LEVEL TROUGH. FARTHER SOUTH...PERHAPS A LINGERING SHOWER
ACROSS THE SOUTH CENTRAL...BUT EXPECT INCREASING SUBSIDENCE
THROUGH THE DAY WITH HIGH PRESSURE BUILDING OVER THE AREA. BREEZY
CONDITIONS DURING THE MORNING AND EARLY AFTERNOON WITH DIMINISHING
WINDS MID TO LATE AFTERNOON AS THE SURFACE HIGH BUILDS OVER THE
STATE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 216 PM CDT WED SEP 16 2015
SHOWERS AND THUNDERSTORMS HIGHLIGHT THE FORECAST FOR THURSDAY
NIGHT AND FRIDAY...WHILE DRY AND SEASONABLE CONDITIONS BECOME THE
FOCUS FOR THE WEEKEND.
THURSDAY NIGHT...A DEPARTING SHORTWAVE WILL KEEP AN ISOLATED SHOWER
OR TWO POSSIBLE IN THE NORTHEAST PART OF THE COUNTY WARNING AREA...
WITH A BRIEF PERIOD OF CLEARING ACROSS THE STATE FROM WEST TO EAST.
EARLY FRIDAY MORNING...THE NEXT SHORTWAVE WILL MOVE INTO SOUTH
DAKOTA FROM WYOMING...INCREASING CLOUD COVER AND PRECIPITATION
CHANCES OVER OUR SOUTHERN ZONES. 12Z NAM/GFS MODEL RUNS SUGGEST THE
BEST CHANCES FOR SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM WILL
RESIDE OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA...MAINLY ALONG
AND SOUTH OF INTERSTATE 94 FRIDAY MORNING AND INTO THE EARLY
AFTERNOON. MEAGER INSTABILITY FROM MODEL FORECAST SOUNDINGS SHOULD
KEEP THUNDERSTORM COVERAGE AND STRENGTH TO A MINIMUM. HIGH
TEMPERATURES ON FRIDAY WILL REMAIN ON THE COOL SIDE...GENERALLY IN
THE 60S.
SATURDAY WILL FEATURE DRY AND SEASONABLE CONDITIONS WITH HIGHS IN
THE LOWER 70S. PLEASANT WEATHER WILL CONTINUE THROUGH MONDAY...WITH
TEMPERATURES WARMING SLIGHTLY EACH DAY. THE NEXT CHANCES FOR
PRECIPITATION WILL BE OVERNIGHT MONDAY AND INTO TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 651 PM CDT WED SEP 16 2015
SCATTERED TO NUMEROUS RAIN SHOWERS WITH A FEW THUNDERSTORMS WILL
MOVE ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS EVENING AND
TONIGHT. CEILINGS ARE EXPECTED TO LOWER TO MVFR AT KISN/KDIK/KMOT
TONIGHT. KJMS AND KBIS ARE MORE UNCERTAIN REGARDING POTENTIAL
STRATUS IMPACTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...ZH
AVIATION...AYD
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 GRAND FORKS ND
ISSUED BY NATIONAL WEATHER SERVICE BISMARCK ND
1216 PM CDT TUE SEP 15 2015
.UPDATE...
ISSUED AT 1215 PM CDT TUE SEP 15 2015
LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS SHOW LOW CLOUDS
ALONG AND AHEAD OF AN ADVANCING WARM FRONT WHICH IS CURRENTLY
LOCATED FROM JUST SOUTH OF DEVILS LAKE/KDVL ARCHING NORTHEAST TO
ROSEAU MUNICIPAL AIRPORT/KROX. SOUTH OF THE WARM FRONT SCT/BKN
HIGH CLOUDS WITH GUSTY SOUTH-SOUTHEASTERLY WINDS BETWEEN 15KT AND
25KT. THE LATEST HRRR CONTINUES TO SHOW THE AFOREMENTIONED WARM
FRONT AND ASSOCIATED LOW CLOUDS LIFTING NORTH AND REACHING THE
FAR NORTHERN BORDER BY 19Z/1400 CDT. LOCAL/REGIONAL RADAR SHOWS
POSSIBLE SPRINKLES OR A LIGHT SHOWER AT BEST IN MY FAR NORTHWEST
CWA...WITHIN THE VICINITY OF THE DEVILS LAKE BASIN AND WILL
CONTINUE TO ADVERTISE ISOLATED SHOWERS THROUGH 19Z. REST OF
FORECAST REMAINS ON TRACK.
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 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.
&&
$$
UPDATE...SIMOSKO
SHORT TERM...VOELKER
LONG TERM...SPEICHER/VOELKER
AVIATION...SIMOSKO
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 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 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
NWS PENDLETON OR
843 PM PDT WED SEP 16 2015
.UPDATE...A WEAK WAVE IS MOVING ACROSS THE EASTERN PART OF THE
AREA AND SHOULD EXIT IN THE NEXT FEW HOURS. THIS WAVE HAS BROUGHT
VERY MODEST AMOUNTS OF RAIN IN SOME LOCATIONS...UP TO A COUPLE OF
HUNDREDTHS OF AN INCH AT MOST, WHILE MUCH OF THE AREA REMAINED
DRY. SATELLITE IMAGERY SHOW ANOTHER STRONGER WAVE MOVING SOUTH
ALONG THE NORTHERN WASHINGTON AREA AND SHOULD ARRIVE IN OUR AREA
LATER NIGHT AND TOMORROW MORNING WITH MORE GENEROUS AMOUNTS OF
RAIN LIKELY. CONSIDERED DROPPING POPS THROUGH MIDNIGHT BUT THE
SHORT RANGE HRRR MODEL SHOWS AN INCREASE IN ACTIVITY IN THE NEXT
FEW HOURS IN CENTRAL OREGON AND THEN MOVING THROUGH THE AREA, SO
LEFT POPS AS IS. RADAR DOES SHOW A SLOW GENERAL UPWARD TREND IN
THE SHOWER ACTIVITY. MADE SOME WIND ADJUSTMENTS THROUGH THE REST
OF THE NIGHT BUT NOTHING VERY SIGNIFICANT. ALSO MADE A FEW
TEMPERATURE ADJUSTMENTS UPWARD DUE TO THE HEAVY CLOUD COVER AND
SLIGHTLY STRONGER WINDS. FORECAST UPDATE ALREADY OUT. PERRY
&&
.PREV DISCUSSION... /ISSUED 415 PM PDT WED SEP 16 2015/
SHORT TERM...TONIGHT THROUGH SATURDAY...A BROAD AND DEEP UPPER
LEVEL TROUGH REMAINS OVER THE WESTERN US. THERE ARE A COUPLE OF
SHORTWAVES IN THE PATTERN THAT WILL IMPACT THE AREA. THE FIRST IS
COMING INTO SOUTHWEST OREGON THAT WILL SPREAD SOME PRECIPITATION
INTO CENTRAL OREGON LATE TODAY AND THEN OVER THE REST OF THE
FORECAST AREA OVERNIGHT. THE SECOND IS SLIDING DOWN THE COAST OF
BRITISH COLUMBIA AND WILL MOVE ACROSS THE FORECAST AREA ON THURSDAY
KEEPING US UNDER A HIGH THREAT OF PRECIPITATION. PRECIPITATION
AMOUNTS WILL RANGE FROM A HALF INCH OR MORE IN THE MOUNTAINS TO A
TENTH TO ONE QUARTER OF AN INCH IN THE BASIN THROUGH THURSDAY
EVENING. FOLLOWING THE PASSAGE OF THIS SECOND SYSTEM WITH WEATHER
PATTERN WILL CHANGE. THE TROUGH OVER THE REGION NOW WILL MOVE OFF TO
THE EAST PLACING US UNDER A DRY WESTERLY FLOW THROUGH SATURDAY. WE
WILL SEE TEMPERATURES BEGIN TO WARM ON FRIDAY AND SATURDAY.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY AFTERNOON...A
MID/UPPER LEVEL SHORT WAVE WILL BRING INCREASING MOISTURE ALONG THE
EAST SLOPES OF THE CENTRAL WASHINGTON CASCADE SATURDAY NIGHT THUS
INTRODUCING A LOW CHANCE OF SHOWERS NEAR THE WASHINGTON CASCADE
CRESTS SATURDAY NIGHT INTO SUNDAY MORNING. THE SHORT WAVE PUSHES A
COLD FRONT THROUGH THE REGION ON MONDAY. THE SHORT WAVE AND COLD
FRONT WILL GIVE THE EAST SLOPES OF THE WASHINGTON CASCADES SHOWERS
LIKELY MONDAY AFTERNOON AND MONDAY EVENING AND JUST A SLIGHT CHANCE
OF SHOWERS ALONG THE EAST SLOPES OF THE CENTRAL AND NORTHERN OREGON
CASCADES AND IN THE NORTHERN BLUE MOUNTAINS AND THE WALLOWA
MOUNTAINS ON MONDAY. OTHERWISE, FLOW ALOFT ASSOCIATED WITH THE SHORT
WAVE WILL BE WESTERLY THUS PRODUCING DOWNSLOPE WINDS AND SINKING AIR
MOTION FOR DRY CONDITIONS ELSEWHERE IN FORECAST AREA FOR A DRY COLD
FRONT AT LOWER ELEVATIONS. THE SHORT WAVE WILL EXIT THE REGION LATE
MONDAY NIGHT WITH AN UPSTREAM FLAT RIDGE OF HIGH PRESSURE MOVING
INTO THE PACIFIC NORTHWEST FOR TUESDAY THROUGH WEDNESDAY FOR DRY
CONDITIONS PERSISTING THROUGH THE EXTENDED PERIOD. POLAN
AVIATION...00Z TAFS...VFR CONDITIONS WILL OCCUR FOR THE NEXT 24
HOURS. A SYSTEM WILL MOVE OVER THE AREA BEGINNING THIS EVENING. CIGS
WILL HAVE LOWERED TO 5000-7000 FT AGL AFTER 17/00Z. PERIODS OF
STRATIFORM RAIN WILL SPREAD INTO CENTRAL OREGON AFTER MID AFTERNOON
AND SHOULD BEGIN AT KBDN AND KRDM BY 16/22-23Z. RAIN THEN SPREADS TO
KDLS AND KYKM BY EARLY THIS EVENING, THEN ARRIVE AT KPSC, KPDT AND
KALW BY 17/09Z. CIGS MAY BRIEFLY DECREASE TO MVFR DURING HEAVIER
RAIN. THE RAIN IS EXPECTED TO END AT TAF SITES BY 17TH/17Z-18Z.
WINDS WILL REMAIN LESS THAN 10 KTS FOR THE NEXT 18 HOURS, AND THEN
INCREASE TO 12-15 KTS WEDNESDAY AFTERNOON. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 51 65 47 72 / 60 70 10 0
ALW 54 67 50 74 / 60 70 20 0
PSC 53 71 49 77 / 60 70 10 0
YKM 45 68 43 75 / 60 70 10 0
HRI 53 69 48 75 / 60 70 10 0
ELN 44 66 42 73 / 60 70 10 10
RDM 39 61 38 73 / 60 70 10 0
LGD 44 59 42 69 / 60 80 20 10
GCD 44 62 40 73 / 70 90 10 0
DLS 52 70 50 77 / 60 70 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/99/99
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 314 PM CDT WED SEP 16 2015
WEAK CONVECTION OVER CLEAR LAKE WILL CONTINUE TO PUSH OFF INTO
MINNESOTA THIS AFTERNOON. HRRR SHOWS ADDITIONAL WEAK/SCATTERED
REDEVELOPMENT...THE DISORGANIZATION LIKELY OWING TO A LACK OF STRONG
FORCING ALOFT. THIS AREA MAY EXPERIENCE SOME ADDITIONAL MORE
ORGANIZED ELEVATED CONVECTION AS A LOW LEVEL JET DEVELOPS THIS
EVENING...HOWEVER THE MAIN FOCUS OF THE JET WILL SHIFT EAST OF THE
CWA. A WAVE ALOFT WILL PROVIDE FOR INCREASING MID LEVEL MOISTURE
WEST RIVER...SHIFTING EAST OVERNIGHT. SOUNDINGS ARE DRY BELOW
10KFT...WITH VERY LIMITED INSTABILITY ALOFT...SUGGESTING SCATTERED
VERY LIGHT SHOWERS WITH THE OCCASIONAL LIGHTING STRIKE. CANADIAN
HIGH PRESSURE NOSING INTO THE CWA THURSDAY WILL ALLOW FOR MORE
AVERAGE DAYTIME TEMPERATURES. MODELS CONTINUE TO GENERATE A RATHER
PROMINENT QPF BULLSEYE WEST RIVER INTO CENTRAL COUNTIES FRIDAY IN
THE VICINITY OF AN INVERTED TROF...WITH FAVORABLE PLACEMENT OF A
SHARED ENERGY AREA AND Q VECTOR BULLSEYE. TO THE EAST...WE WILL SEE
A DRY NORTHEAST FETCH...WHICH WILL LIMIT QPF/POPS. 850MB
TEMPERATURES WILL HAVE BOTTOMED OUT AROUND +5C BY THAT POINT...SO
ANTICIPATE MUCH OF THE FORECAST AREA WILL STRUGGLE TO TOP 60F.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 314 PM CDT WED SEP 16 2015
HIGH PRESSURE WILL BE CENTERED OVER NEBRASKA WHEN THE PERIOD
BEGINS...THEN GETS QUICKLY PUSHED EASTWARD AHEAD OF AN APPROACHING
TROUGH SATURDAY NIGHT. THE TROUGH/FRONT WILL SLOWLY STRENGTHEN AND
LOOKS TO FINALLY TRACK ACROSS THE CWA TUESDAY AND
WEDNESDAY...BECOMING THE FOCUS FOR POTENTIAL PRECIPITATION. BEST
CHANCES WILL BE ACROSS THE EASTERN PART OF THE CWA WHERE SOME
INSTABILITY IS NOTED IN THE MODELS. NOT MUCH IN THE WAY OF UPPER
LEVEL ENERGY...SO WILL KEEP POPS LOW FOR THE TIME BEING.
WILL SEE A GRADUAL WARMING TREND DURING THE FIRST HALF OF THE PERIOD
WITH HIGHS IN THE UPPER 60S AND LOWER 70S SATURDAY...MAINLY IN THE
70S ON SUNDAY...AND IN THE UPPER 70S TO MID 80S MONDAY. HIGHS IN THE
70S TO AROUND 80 WILL BE COMMON TUESDAY AND WEDNESDAY...DEPENDING ON
CLOUD COVER AND POSSIBLE PRECIPITATION. OVERNIGHT LOWS WILL BE IN
THE UPPER 40S TO MID 50S THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 643 PM CDT WED SEP 16 2015
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH MIDDAY
THURSDAY. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE
NORTHWEST AND INCREASE INTO THE 15 TO 30 MPH RANGE THURSDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...DORN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
628 PM CDT WED SEP 16 2015
.AVIATION...
VFR WITH SOUTHERLY WINDS OF 10-15 KNOTS...BECOMING GUSTY BY THU
AFTN. SMALL TS NEARING PVW AT 627 PM IS ON TRACK TO DISSIPATE
SHORTLY...HOWEVER ADDITIONAL ISO-SCT TS DEVELOPMENT SEEMS LIKELY
THU AFTERNOON MAINLY WEST OF PVW.
&&
.PREV DISCUSSION... /ISSUED 320 PM CDT WED SEP 16 2015/
SHORT TERM...
LOOKS LIKE CONDITIONS ARE A BIT MORE FAVORABLE FOR ISOLATED
THUNDERSTORMS ACROSS THE NORTHWESTERN SOUTH PLAINS THIS AFTERNOON
AND EARLY EVENING. THE LEE SURFACE TROUGH AXIS IS A BIT FARTHER
EAST INTO THE WESTERN SOUTH PLAINS AND A FAIRLY WELL DEVELOPED CU
FIELD HAS APPEARED OVER THE LAST HOUR IN EASTERN NEW MEXICO AND
THE WESTERN COLUMN OF COUNTIES ALONG THE TX/NM BORDER. FORECAST
SOUNDINGS SHOW THAT THERE IS A BIT BETTER INSTABILITY WITH ML AND
SB CAPES RANGING FROM AROUND 500-750 J/KG ALONG THE TROUGH AXIS TO
NEAR 2000 J/KG ACROSS THE NORTHERN ROLLING PLAINS. HOWEVER...THERE
IS A FAIRLY STRONG CAP IN PLACE ACROSS THE EASTERN HALF OF THE
FORECAST AREA SO THE QUESTION BECOMES WHERE A SWEET SPOT COULD
EMERGE FOR THE DEVELOPMENT OF STORMS. LATEST SATELLITE AND RADAR
LOOPS...AS WELL AS A LOOK TO THE WEST FROM THE FORECAST
OFFICE...SHOWS THAT STORMS ARE CLOSE TO INITIATING IN BAILEY
COUNTY/NEAR MULESHOE. BASES ARE EXPECTED TO BE FAIRLY HIGH AT
AROUND 10KFT DUE TO DEEP DAYTIME MIXING SO PRECIPITATION WILL HAVE
TO DEAL WITH QUITE A BIT OF EVAPORATION BEFORE REACHING THE
GROUND. THIS MAY ALSO RESULT IN SOME DOWNBURSTS THAT COULD TRY TO
GET UP TO AROUND 50 MPH SO THAT WILL NEED TO BE WATCHED THROUGH
THE LATE AFTERNOON. NEXT ISSUE IS HOW FAR SOUTHEAST ANY STORMS CAN
MAKE IT. HIGH RESOLUTION MODELS ALL HAVE CONVECTION IN THEM BUT
ARE STRUGGLING WITH HOW FAR SOUTHEAST TO PUSH THE STORMS BEFORE
THEY DISSIPATE. THE HRRR AND NSSL-WRF BOTH HAVE STORMS MAKING IT
CLOSE TO LUBBOCK BUT ALL OTHER MODELS KEEP PRECIPITATION NORTH AND
WEST OF THE CITY. THEY ARE ALL IN AGREEMENT THAT COVERAGE WILL BE
ISOLATED AT BEST. SO...WILL RUN ISOLATED POPS THROUGH 03Z
NORTHWEST OF A TULIA TO PLAINS LINE.
TEMPERATURES TOMORROW MORNING WILL BE A BIT WARMER AS BOUNDARY LAYER
MOISTURE WILL BE A BIT HIGHER ACROSS THE REGION THANKS TO
CONTINUED SOUTHERLY TO SOUTHEASTERLY FLOW AT THE SURFACE. WE WILL
AGAIN SEE THE POSSIBILITY OF THUNDERSTORMS TOMORROW AFTERNOON AGAIN
ALONG AND EAST OF THE SURFACE TROUGH. 12Z RUNS CONTINUE TO KEY ON
THE NORTHWESTERN SOUTH PLAINS TO BE THE MOST FAVORED AREA FOR
CONVECTION AND KEPT POPS HIGHEST ACROSS THIS AREA. THIS INCLUDES A
SLIVER OF LOW END CHANCE POPS IN THERE AS WELL AS COVERAGE CONTINUES
TO BE HIGHER THAN IN PREVIOUS RUNS. HIGH TEMPERATURES WILL BE
FAIRLY CLOSE TO TODAY BUT PERHAPS A SHADE ON THE COOL SIDE THANKS TO
THE INCREASED MOISTURE AND POSSIBLY INCREASED CLOUD COVER AS WELL.
JORDAN
LONG TERM...
THE UA RIDGE CENTERED SOUTH OF THE SOUTH PLAINS AND ROLLING PLAINS
LATE THIS AFTN...WILL SET THE STAGE FOR MONSOONAL MOISTURE TO BE
CAPABLE OF BENDING IN ACROSS THE REGION COMMENCING TOMORROW AND
PERSISTING INTO EARLY WEEKEND. A NW PACIFIC UA LOW CURRENTLY
MOVING ONSHORE ACROSS OREGON IS PROGGED TO TRANSLATE ENE TO ACROSS
THE NRN PLAINS BY FRIDAY. IT WILL SEND DOWN A SFC TROUGH/SLIGHTLY
BREEZY COLD FRONT THAT IS STILL ON TRACK TO IMPINGE ON THE CWA
FRIDAY NIGHT...WHICH WILL INTERACT WITH AN ALREADY MOIST
ATMOSPHERE /PWATS OF 0.75-1.50 INCHES/ COURTESY OF PERSISTENT SRLY
SFC FLOW. THIS WILL RESULT IN CHANCES OF PRECIP WITH THE GFS AND
ECMWF BEING MOST BULLISH WRT TO THE SPATIAL DISTRIBUTION OF THE
PRECIP /SCATTERED-WIDESPREAD PRECIP/...VERSUS THE MORE
PESSIMISTIC NAM /PRECIP CONFINED TO OFF THE CAPROCK/. IF THE GFS
AND ECMWF ARE INDEED HANDLING THE PRECIP BETTER THAN THE OUTLIER
NAM...GIVEN THE ANTICIPATED PWATS AND DEPENDING ON THE SPEED OF
THE STORMS...COULD SEE BRIEF MODERATE RAINFALL.
PROGRESSIVE FLOW ACROSS THE NRN U.S. TIER WILL RESULT IN THE UA
RIDGE GETTING SHOVED A BIT FARTHER SOUTH AND AWAY FROM THE REGION BY
SATURDAY...AND THUS FLOW ALOFT WILL VEER FROM SWRLY FLOW TO W-NW
FLOW THROUGHOUT THE WEEKEND. THE COLD FRONT/SFC TROUGH IS EXHIBITED
TO STALL JUST SOUTH OF THE CWA SATURDAY AFTN/EVENING...THOUGH COULD
RETURN AS A WARM FRONT WITH AN UPSLOPE SFC REGIME ENVELOPING THE
REGION...COUPLED WITH A BIT OF ISENTROPIC UPGLIDE AND THE PASSAGE OF
A WEAK EMBEDDED IMPULSE ACROSS THE PANHANDLE REGION. EVEN THOUGH
THE MONSOONAL MOISTURE WILL BE THINNING OUT QUITE A BIT BY
SUNDAY...LINGERING PRECIP WILL STILL EXIST AS A SECOND SLIGHTLY
STRONGER UA DISTURBANCE MOVES ACROSS THE CNTRL PLAINS/PANHANDLE
REGION.
THE EMERGENCE OF AMPLIFIED UA RIDGING TO OUR WEST EARLY NEXT WEEK IS
SHOWN TO QUICKLY EXPAND TO ACROSS THE SOUTHERN PLAINS
TUESDAY/WEDNESDAY. WHETHER OR NOT THE BRIEF PERIOD OF NWRLY FLOW
ALOFT AND A POSSIBLE WEAKNESS ALONG THE ERN PERIPHERY OF THE UA
RIDGE IS ENOUGH TO GENERATE RATHER LIGHT QPF SIGNALS ACROSS PORTIONS
OF THE CWA /AS HINTED AT BY THE ECMWF AND THE GFS/ IS
DEBATABLE...AS IT WILL BE HIGHLY DEPENDENT ON THE STRENGTH OF THE
SAID UA RIDGE. WILL OPT TO MAINTAIN NIL POPS BEYOND SUNDAY NIGHT
ATTM.
ABOVE NORM TEMPS EXPECTED THROUGH FRIDAY /90S/...WHERE THEREAFTER
TEMPS REMINISCENT OF FALL WILL OCCUR FOR THE WEEKEND /70S AND 80S/.
TEMPS WILL GRADUALLY WARMUP TO AROUND SEASONAL NORMS THROUGH MID-
WEEK.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93
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
1054 PM CDT WED SEP 16 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 232 PM CDT WED SEP 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD
FRONT STRETCHING FROM NORTHWEST MINNESOTA TO THE PANHANDLE OF TEXAS
EARLY THIS AFTERNOON. QUIET CONDITIONS ARE PREVAILING ACROSS THE
REGION OTHER THAN SOME MID AND HIGH CLOUDS PASSING OVERHEAD ON THE
LEADING EDGE OF A MORE MOISTURE-RICH AIRMASS. THE FRONTAL ZONE IS
ALSO LARGELY INACTIVE DUE TO MID-LEVEL CAPPING. EVEN FARTHER
UPSTREAM...LOW PRESSURE IS MOVING EAST OVER NORTHERN WYOMING ON THE
LEADING EDGE OF THE WESTERN NOAM TROUGH. AS THE LOW PRESSURE SYSTEM
AND COLD FRONT MOVE EAST...THE POTENTIAL FOR SHOWERS AND STORMS IS
THE MAIN FORECAST CONCERN IN THE SHORT-TERM.
TONIGHT...LOW PRESSURE WILL MOVE NORTHEAST ACROSS THE DAKOTAS TO THE
BORDER OF MINNESOTA WHILE THE COLD FRONT REMAINS RELATIVELY
STATIONARY. AHEAD OF THESE SYSTEMS...SOUTHWEST WINDS WILL PULL UP
MID-LEVEL DRY AIR ACROSS THE REGION FOR THE EVENING...WHICH LOOKS
MOSTLY CLEAR AND MILD. BUT MODELS APPEAR UNANIMOUS IN DEVELOPING A
SHORTWAVE IMPULSE OVERNIGHT AND PUSHING IT INTO NORHTWEST WISCONSIN
BY 12Z. THIS WAVE IN CONCERT WITH MID-LEVEL MOISTURE ADVECTION AND
STEEP MID-LEVEL LAPSE RATES WILL BRING A CHANCE OF ELEVATED SHOWERS
AND STORMS TO CENTRAL AND NORTH-CENTRAL WI LATE. BEST CHANCES WILL
BE OVER N-C WI CLOSEST TO THE MID-LEVEL WAVE. LOCATIONS FURTHER
EAST SHOULD ENJOY A MOSTLY CLEAR NIGHT. LOWS WILL MAINLY FALL INTO
THE LOW TO MID 60S.
THURSDAY...SCATTERED SHOWERS AND STORMS MAY BE ONGOING EARLY IN THE
MORNING OVER CENTRAL AND NORTH-CENTRAL WI. FORCING VIA SHORTWAVE
ENERGY WILL LIFT TO THE NORTHEAST BY EARLY AFTERNOON SO THINK THE
COVERAGE OF ANY CONVECTION WILL BE DECREASING BY MID TO LATE
MORNING. MANY LOCATIONS IN THIS AREA ARE LIKELY TO SEE A BREAK IN
THE SHOWER ACTIVITY...BUT ITS HARD TO DETERMINE HOW LINGERING CLOUD
COVER WILL DISRUPT THE HEATING CURVE. THE ELEVATED NATURE OF THE
CONVECTION WOULD ARGUE FOR AT LEAST SOME BREAKS IN THE
CLOUDS...WHICH SHOULD BE SUFFICIENT FOR TEMPS TO RISE INTO THE UPPER
70S. WITH DEWPOINTS RISING INTO THE MID TO UPPER 60S...ML CAPES
COULD REACH INTO THE 1000-1500 J/KG RANGE WITH LITTLE CAP BY LATE
AFTERNOON. AS A RESULT...THINK SHOWERS AND THUNDERSTORMS WILL
REDEVELOP DURING THE MID TO LATE AFTERNOON HOURS...MAINLY OVER
CENTRAL AND NORTH-CENTRAL WI...BUT A FEW STORMS COULD FIRE FURTHER
EAST. POTENTIAL FOR STRONG TO SEVERE STORMS IS POSSIBLE BY THIS
TIME AS WIND FIELDS STRENGTHEN ALOFT. MORE ORGANIZED CONVECTION
COULD ALSO BE APPROACHING FROM THE NORTHWEST BY EARLY IN THE
EVENING. DAMAGING WINDS AND HEAVY RAINFALL WILL BE THE MAIN THREATS.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 232 PM CDT WED SEP 16 2015
MAIN FCST CONCERN IS SVR TSTM POTENTIAL THU EVG...AND PCPN TRENDS
THROUGH SATURDAY MORNING.
SHOWERS AND TSTMS WILL BE ON THE INCREASE THURSDAY EVG...AS A S/W
TROF...RRQ OF AN UPPER LEVEL JET AND COLD FRONT IMPACT THE REGION.
ALTHOUGH THE BEST THREAT SHOULD OCCUR TO OUR WEST EARLIER IN THE
DAY...CAPE AROUND 1000 J/KG AND DEEP LAYER SHEAR OF 25-30 KTS
MAY SUPPORT ISOLD STG/SVR TSTMS OVER NC/C WI INTO THE EARLY EVG.
SHOWERS WILL DECREASE FROM WEST TO EAST LATE THU NGT INTO EARLY
FRIDAY...RESULTING IN A BRIEF BREAK IN THE PCPN MIDDAY.
A POTENT NEGATIVELY-TILTED S/W TROF IS EXPECTED TO INDUCE
CYCLOGENESIS ALONG THE LINGERING FRONTAL BOUNDARY FRIDAY NIGHT...
WITH THE DEEPENING SFC LOW TRACKING THROUGH SE WI AND LOWER
MICHIGAN. MODELS HAVE TRENDED FARTHER WEST AND STRONGER WITH
THIS SYSTEM...SO HAVE RAISED POPS TO LIKELY NW AND CATEGORICAL
SE. THE GFS/NAM MODELS SHOW TWO QPF MAXS...ONE OVER SE/EC WI
IN ASSOCIATION WITH A REGION OF STG ISENT LIFT...AND ANOTHER
IN WC/NC WI DUE TO THE UPPER DEFORMATION ZONE. HAVE ATTEMPTED
TO DEPICT THIS PATTERN IN THE QPF GRIDS...THOUGH AMOUNTS MAY
NEED TO BE RAISED WITH SUBSEQUENT FCSTS. LINGERING SHOWERS
SHOULD TAPER OFF EARLY SATURDAY...FOLLOWED BY DECREASING CLOUDS
IN THE AFTERNOON.
HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE END OF THE
WEEKEND AND BEGINNING OF THE NEXT WORK WEEK...LEADING TO
A PERIOD OF PLEASANT WEATHER WITH ABUNDANT SUNSHINE AND
SEASONABLE TEMPERATURES. A WEAK COLD FRONT MAY BRING A
CHANCE OF SHOWERS AND TSTMS TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1054 PM CDT WED SEP 16 2015
SHOULD BE MAINLY VFR TONIGHT THOUGH SOME SHOWERS ARE
NOT OUT OF THE QUESTION OVER THE NORTH. LOW LEVEL WIND SHEAR IS
LIKELY WITH SOUTHWEST WINDS AROUND 35 KNOTS AT 1000` AGL AND
LIGHT SOUTH SURFACE WINDS. THURSDAY WILL BE CLOUDY WITH SHOWERS
AND THUNDERSTORMS ARRIVING FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON. SOME STRONG OR SEVERE STORMS ARE POSSIBLE IN THE
AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
640 PM CDT WED SEP 16 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 232 PM CDT WED SEP 16 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD
FRONT STRETCHING FROM NORTHWEST MINNESOTA TO THE PANHANDLE OF TEXAS
EARLY THIS AFTERNOON. QUIET CONDITIONS ARE PREVAILING ACROSS THE
REGION OTHER THAN SOME MID AND HIGH CLOUDS PASSING OVERHEAD ON THE
LEADING EDGE OF A MORE MOISTURE-RICH AIRMASS. THE FRONTAL ZONE IS
ALSO LARGELY INACTIVE DUE TO MID-LEVEL CAPPING. EVEN FARTHER
UPSTREAM...LOW PRESSURE IS MOVING EAST OVER NORTHERN WYOMING ON THE
LEADING EDGE OF THE WESTERN NOAM TROUGH. AS THE LOW PRESSURE SYSTEM
AND COLD FRONT MOVE EAST...THE POTENTIAL FOR SHOWERS AND STORMS IS
THE MAIN FORECAST CONCERN IN THE SHORT-TERM.
TONIGHT...LOW PRESSURE WILL MOVE NORTHEAST ACROSS THE DAKOTAS TO THE
BORDER OF MINNESOTA WHILE THE COLD FRONT REMAINS RELATIVELY
STATIONARY. AHEAD OF THESE SYSTEMS...SOUTHWEST WINDS WILL PULL UP
MID-LEVEL DRY AIR ACROSS THE REGION FOR THE EVENING...WHICH LOOKS
MOSTLY CLEAR AND MILD. BUT MODELS APPEAR UNANIMOUS IN DEVELOPING A
SHORTWAVE IMPULSE OVERNIGHT AND PUSHING IT INTO NORHTWEST WISCONSIN
BY 12Z. THIS WAVE IN CONCERT WITH MID-LEVEL MOISTURE ADVECTION AND
STEEP MID-LEVEL LAPSE RATES WILL BRING A CHANCE OF ELEVATED SHOWERS
AND STORMS TO CENTRAL AND NORTH-CENTRAL WI LATE. BEST CHANCES WILL
BE OVER N-C WI CLOSEST TO THE MID-LEVEL WAVE. LOCATIONS FURTHER
EAST SHOULD ENJOY A MOSTLY CLEAR NIGHT. LOWS WILL MAINLY FALL INTO
THE LOW TO MID 60S.
THURSDAY...SCATTERED SHOWERS AND STORMS MAY BE ONGOING EARLY IN THE
MORNING OVER CENTRAL AND NORTH-CENTRAL WI. FORCING VIA SHORTWAVE
ENERGY WILL LIFT TO THE NORTHEAST BY EARLY AFTERNOON SO THINK THE
COVERAGE OF ANY CONVECTION WILL BE DECREASING BY MID TO LATE
MORNING. MANY LOCATIONS IN THIS AREA ARE LIKELY TO SEE A BREAK IN
THE SHOWER ACTIVITY...BUT ITS HARD TO DETERMINE HOW LINGERING CLOUD
COVER WILL DISRUPT THE HEATING CURVE. THE ELEVATED NATURE OF THE
CONVECTION WOULD ARGUE FOR AT LEAST SOME BREAKS IN THE
CLOUDS...WHICH SHOULD BE SUFFICIENT FOR TEMPS TO RISE INTO THE UPPER
70S. WITH DEWPOINTS RISING INTO THE MID TO UPPER 60S...ML CAPES
COULD REACH INTO THE 1000-1500 J/KG RANGE WITH LITTLE CAP BY LATE
AFTERNOON. AS A RESULT...THINK SHOWERS AND THUNDERSTORMS WILL
REDEVELOP DURING THE MID TO LATE AFTERNOON HOURS...MAINLY OVER
CENTRAL AND NORTH-CENTRAL WI...BUT A FEW STORMS COULD FIRE FURTHER
EAST. POTENTIAL FOR STRONG TO SEVERE STORMS IS POSSIBLE BY THIS
TIME AS WIND FIELDS STRENGTHEN ALOFT. MORE ORGANIZED CONVECTION
COULD ALSO BE APPROACHING FROM THE NORTHWEST BY EARLY IN THE
EVENING. DAMAGING WINDS AND HEAVY RAINFALL WILL BE THE MAIN THREATS.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 232 PM CDT WED SEP 16 2015
MAIN FCST CONCERN IS SVR TSTM POTENTIAL THU EVG...AND PCPN TRENDS
THROUGH SATURDAY MORNING.
SHOWERS AND TSTMS WILL BE ON THE INCREASE THURSDAY EVG...AS A S/W
TROF...RRQ OF AN UPPER LEVEL JET AND COLD FRONT IMPACT THE REGION.
ALTHOUGH THE BEST THREAT SHOULD OCCUR TO OUR WEST EARLIER IN THE
DAY...CAPE AROUND 1000 J/KG AND DEEP LAYER SHEAR OF 25-30 KTS
MAY SUPPORT ISOLD STG/SVR TSTMS OVER NC/C WI INTO THE EARLY EVG.
SHOWERS WILL DECREASE FROM WEST TO EAST LATE THU NGT INTO EARLY
FRIDAY...RESULTING IN A BRIEF BREAK IN THE PCPN MIDDAY.
A POTENT NEGATIVELY-TILTED S/W TROF IS EXPECTED TO INDUCE
CYCLOGENESIS ALONG THE LINGERING FRONTAL BOUNDARY FRIDAY NIGHT...
WITH THE DEEPENING SFC LOW TRACKING THROUGH SE WI AND LOWER
MICHIGAN. MODELS HAVE TRENDED FARTHER WEST AND STRONGER WITH
THIS SYSTEM...SO HAVE RAISED POPS TO LIKELY NW AND CATEGORICAL
SE. THE GFS/NAM MODELS SHOW TWO QPF MAXS...ONE OVER SE/EC WI
IN ASSOCIATION WITH A REGION OF STG ISENT LIFT...AND ANOTHER
IN WC/NC WI DUE TO THE UPPER DEFORMATION ZONE. HAVE ATTEMPTED
TO DEPICT THIS PATTERN IN THE QPF GRIDS...THOUGH AMOUNTS MAY
NEED TO BE RAISED WITH SUBSEQUENT FCSTS. LINGERING SHOWERS
SHOULD TAPER OFF EARLY SATURDAY...FOLLOWED BY DECREASING CLOUDS
IN THE AFTERNOON.
HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE END OF THE
WEEKEND AND BEGINNING OF THE NEXT WORK WEEK...LEADING TO
A PERIOD OF PLEASANT WEATHER WITH ABUNDANT SUNSHINE AND
SEASONABLE TEMPERATURES. A WEAK COLD FRONT MAY BRING A
CHANCE OF SHOWERS AND TSTMS TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 640 PM CDT WED SEP 16 2015
SHOULD BE MAINLY VFR TONIGHT THOUGH SOME SHOWERS ARE
NOT OUT OF THE QUESTION OVER THE NORTH. LOW LEVEL WIND SHEAR IS
LIKELY WITH SOUTHWEST WINDS AROUND 35 KNOTS AT 1000` AGL AND LIGHT
SOUTH SURFACE WINDS. THURSDAY WILL BE CLOUDY WITH SHOWERS AND
THUNDERSTORMS ARRIVING FROM THE WEST DURING THE AFTERNOON. SOME
STRONG OR SEVERE STORMS ARE POSSIBLE IN THE AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......RDM
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
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...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 LINCOLN IL
335 AM CDT THU SEP 17 2015
.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT THU SEP 17 2015
The approaching cold front from the Plains will cause increasing
southerly flow in the lower troposphere, raising moisture levels
across the forecast area. Warm air advection showers are already
nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP
models show spotty showers advancing across our counties west of I-
55 this morning. Most spots will just see sprinkles, but a few
locations could get measurable rain under convective updrafts.
Therefore, we advanced slight chance PoPs into the western counties
over several hours this morning, then diminished just after Noon. A
return of slight chances for Knox and Stark counties is expected
after 3 pm/20z as a shortwave/low pressure begin to move northeast
along the front into Iowa.
Depending on cloud cover, high temps should climb to at or above
yesterdays very warm readings in the mid to upper 80s in the west,
with mid 80s in the east. Held off on low 90s, due to periodic cloud
cover limiting full warming potential.
South winds will become gusty today ahead of the cold front, with
sustained speeds of 15-20 mph, and gusts into the mid to upper 20
mph range this afternoon.
&&
.LONG TERM...(TONIGHT THROUGH Wednesday)
ISSUED AT 335 AM CDT THU SEP 17 2015
Beyond today, the remaining of the forecast has a lot of agreement
in the models overall. The precipitation chances increase tonight
as the front gets closer to the region. The front slows a bit
tomorrow as it runs into mostly parallel flow out of the southwest,
but starts to break down the ridge over the eastern half of the
country. There is the potential for a bit of a break on Friday...but
that will depend highly on mesoscale features and cloud cover during
the day...and keeping the forecast to chance pops a a result. The
second wave is expected to bring increasing pops tomorrow night with
the actual fropa and wind shift coming in the early morning hours
for Saturday. Northwesterly winds for Saturday and lower max temps
in the upper 60s in the northern portions of the state, Central
Illinois in the 70s. More widespread 70s expected for Sunday
afternoon to wrap up the weekend. So far, the mid level temps in
the models are not pointing to a deep chill behind the cold front.
Although a few degrees below normal briefly, a general warming trend
will have Central Illinois back to climatological norms by midweek.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT)
ISSUED AT 1148 PM CDT WED SEP 16 2015
Predominantly VFR aviation weather conditions expected across the
central Illinois terminals through the 06Z TAF valid time. In
fact, most of the first half of the forecast period should see
little, if any, cloud cover. Eventually clouds will slowly
increase from the west with the approach of a slow moving cold
front. A few showers or thunderstorms are possible during the
evening hours, but coverage is expected to be too low to go above
a VCSH mention. Better precipitation chances will arrive after
06Z Friday. Once again, southerly winds will persist through the
period, with winds gusting to around 20 kts during the peak
diurnal mixing times Thursday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 AM CDT THU SEP 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU SEP 17 2015
An upper level trough was deepening across the eastern Pacific and
the western CONUS at 08Z. A stronger shortwave trough was moving
onshore into Washington state while an upper level ridge continued
across the southern Plains into the western Gulf with southwesterly
upper flow across the Central Plains. A few embedded waves were
moving across the Northern Plains early this morning. Isentropic
lift in the 315K-320K layer was developing a few isolated showers in
north central and northeast Kansas. Short range hi resolution
models, including the experimental HRRR show isolated to scattered
elevated convection across the forecast area, but mainly focusing
across northeast Kansas by sunrise. A frontal boundary was located
from central South Dakota to a low pressure area in southwest
Nebraska then into eastern Colorado. A trough moving across the
Northern Plains today should push the front southeast into north
central Kansas later this afternoon then extend from Hiawatha to
Abilene by late evening. The front looks to stall out across the
forecast area after midnight from northwest Missouri into south
central Kansas. Expect the isolated showers and thunderstorms
through the morning hours before moving off to the northeast. Expect
a break for much of the afternoon as there is little in the way of
any lift and convergence along the front is expected to be weak and
forecast soundings show EML capping surface convection for the
afternoon. That said convective inhibition will begin to wane late
in the day and have maintained increasing pops along the frontal
zone. Tonight the low level jet will be orientated parallel to the
frontal boundary with the pooling of moisture near the front,
especially in northeast Kansas initially before shifting to the
southeast through the night. Isentropic lift and convergence are
also initially focused in the northeast and into northwest Missouri
then shifts southward through the night into east central Kansas.
Shear and instability will be sufficient for a few strong to severe
storms tonight. Locally heavy rainfall is also possible where storms
train along the boundary. Mixing to around 850 mb today will make
for highs in the upper 80s to mid 90s. Lows tonight will cool into
the 60s north of the front and lower 70s to its south.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 340 AM CDT THU SEP 17 2015
By Friday morning, the cold front should be stretched across the
southeastern portion of the CWA and lift a bit to the north through
the morning hours. This front finally will progress eastward through
the afternoon and evening hours as the secondary mid-level trough
sweeps into the Northern and Central Plains, thus helping to push
this system eastward out of the area. Models show that we may lose
some of the available lift during the morning hours on Friday, so
there may only be some scattered morning showers and thunderstorms.
However, thunderstorm potential looks to increase during the
afternoon hours and into the evening as the forcing/lift increases
across the area with the progressing front and support from the mid-
level trough approaching the area. Soundings show the cap
potentially eroding away by mid-afternoon, when the front should be
nearly bisecting the CWA from southwest to northeast. This available
lift/forcing combined with limited inhibition by mid-afternoon, CAPE
values increasing to upwards of around 2000 J/kg, and 0-6 km bulk
shear values increasing to at least 35-40kts, should result in the
potential for some severe thunderstorm development mid Friday
afternoon into Friday evening. While the primary hazards will be
damaging winds and large hail, 0-1 km shear and helicity values
suggest even the potential for a few isolated tornadoes as well.
While these afternoon storms should be a bit more progressive, with
PWAT values in the 1.7-1.9 inch range and the low/mid level jets
expected to be nearly parallel to the boundary, cannot rule out the
potential for some locally heavy rain that could potentially lead to
some localized flash flooding. The severe threat should diminish by
late evening with a dry forecast in place for the entire CWA by the
overnight hours (early Saturday morning).
Surface high pressure will surge into the central U.S. behind the
exiting system, ushering cooler air into the region. Have continued
to trend a bit cooler for high temperatures on Saturday as northerly
winds may only allow afternoon highs to reach into the low/mid 70s.
Lows Saturday night should drop into the low 50s. Winds will shift
around to the southeast by Sunday, pushing highs a few degrees
higher into the mid/upper 70s. Models continue to show an embedded
shortwave trough developing within the mid-level flow over the
central U.S. on Sunday, however the best moisture and lift look to
remain further south of the CWA so have kept a dry forecast for
Sunday.
A mid-level ridge will build back into the Southern and Central
Plains by early next week. With surface high pressure shifting east
of the area, southerly winds will help to gradually moderate high
temperatures into the low/mid 80s by Tuesday. Models start diverging
in their solutions by mid-week as the GFS develops an embedded wave
along the western ridge axis that could potentially result in some
precipitation skimming the CWA, while the ECMWF keeps the area dry.
While confidence is low in the precip potential, have only some low-
end slight chance PoPs in for Wednesday night into Thursday.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT)
ISSUED AT 1141 PM CDT WED SEP 16 2015
Low level wind shear will continue through the overnight hours
although occasional gusts at the surface will be possible as
well. Isolated showers with perhaps thunder will develop during
the predawn hours and move eastward towards the taf sites. A cold
front will approach later this evening. Isolated storms could
develop along the front near MHK after sunset. Brief heavy rain
and gusty winds can not be ruled out with any storm.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
232 AM EDT THU SEP 17 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 306 PM EDT WED SEP 16 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS THE UPPER GREAT LAKES
REGION BEING LOCATED BETWEEN AN UPPER RIDGE OVER THE EASTERN CONUS
AND AN UPPER TROUGH OVER THE WESTERN CONUS. THIS HAS LED TO
SOUTHWESTERLY FLOW ACROSS THE UPPER GREAT LAKES REGION AND THERE WAS
A WEAK SHORTWAVE THAT LIFTED NORTHEAST ACROSS THE AREA THIS MORNING.
THIS LED TO CLOUDS/SHOWERS AND EVEN A FEW THUNDERSTORMS OVER THE
WESTERN U.P. UNDER THE STEEP 700-300MB LAPSE RATES. THIS WAVE HAS
LIFTED TO THE NORTHEAST AND BROUGHT MUCH OF THE MID CLOUDS WITH
IT...ALTHOUGH THERE ARE STILL SOME LINGERING SHOWERS/SPRINKLES OVER
THE EAST AND NEAR DULUTH. THE THICKER MID CLOUDS DID HOLD OFF TEMPS
AND WINDS SOME THIS AFTERNOON BUT NOT THAT WE ARE SEEING MORE BREAKS
OVER THE WESTERN HALF OF THE CWA...TEMPERATURES HAVE RISEN INTO THE
UPPER 70S AND LOWER 80S. AS OF 3PM...NWS MARQUETTE IS JUST BELOW OUR
RECORD HIGH FOR TODAY (79) AND WOULD EXPECT THAT TO BE BROKEN IN THE
NEXT HOUR OR TWO. THE CLOUDS DID HELP LIMIT MIXING FROM REACHING THE
STRONGER WINDS ALOFT...BUT HAVE STILL BEEN SEEING 15-25KT WINDS OVER
MUCH OF THE AREA. EXPECT THE INCREASED SUNSHINE OVER THE NEXT COUPLE
HOURS TO LEAD TO SLIGHTLY HIGHER GUSTS THROUGH EARLY EVENING.
THE SURFACE LOW THAT IS CURRENTLY IN NORTHERN ONTARIO WILL CONTINUE
NORTHEAST THIS EVENING AND OVER NORTHERN JAMES BAY. THEN...ANOTHER
WAVE EJECTING NORTHEAST ACROSS EASTERN IDAHO WILL LEAD TO A
STRENGTHENING SURFACE LOW THAT IS CURRENTLY IN NORTHEAST WYOMING.
THIS LOW WILL LIFT NORTHEAST ACROSS THE DAKOTAS TONIGHT AND THEN
INTO NORTHERN ONTARIO ON THURSDAY. EXPECT PRECIPITATION CHANCES
TONIGHT INTO THURSDAY MORNING TO BE SIMILAR TO LAST NIGHT INTO THIS
MORNING WHERE THERE ARE STEEP 750-400MB LAPSE RATES IN PLACE AND
POCKETS OF MOISTURE OVER WESTERN LAKE SUPERIOR INTO FAR WESTERN
UPPER MICHIGAN. IN ADDITION...THERE IS A WEAK SHORTWAVE IN WESTERN
IOWA THAT LOOKS TO LIFT NORTHEAST THROUGH THE AREA. WITH THOSE
FEATURES BRUSHING THE WESTERN HALF OF THE CWA...WILL CONTINUE TO
SHOW SLIGHT CHANCE TO LOW END CHANCES FROM EAST TO WEST TOWARDS THE
MINNESOTA ARROWHEAD. WHILE THE DRY AIR BELOW 700MB WILL LIKELY LIMIT
THE MEASURABLE PRECIP IN SOME AREAS...FEEL THE SUPPORT IS THERE FOR
MEASURABLE RAIN TO OCCUR. ONCE AGAIN...EXPECT WINDS TO STAY UP
ACROSS THE AREA THROUGH THE NIGHT WITH THE STRONG LOW LEVEL JET (TO
45KTS) 2-3KFT ABOVE THE SURFACE. THOSE GUSTY WINDS WILL ALSO KEEP
TEMPERATURES WELL ABOVE THE NORMAL LOWS AND IN THE 60S WITH A FEW
70S OVER THE DOWNSLOPING AREAS OUT WEST.
HEADING INTO TOMORROW AFTERNOON...THE COLD FRONT TRAILING THE
SURFACE LOW LIFTING NORTHEAST FROM THE DAKOTAS INTO NORTHERN ONTARIO
THROUGH THE DAY WILL BE MOVING INTO WESTERN LAKE SUPERIOR DURING THE
LATE AFTERNOON AND EVENING HOURS. BELIEVE THE SHOWERS/THUNDERSTORMS
WILL BE LARGELY FOCUSED ALONG THE FRONT. BUT THERE ARE SOME HINTS AT
DEVELOPMENT OUT AHEAD OF THE FRONT AND TIED TO A SHORTWAVE LIFTING
NORTHEAST ACROSS THE WESTERN U.P. DURING THE AFTERNOON HOURS.
INSTABILITY WILL INCREASE OVER THE AREA WITH 1000-1500 J/KG OF
MLCAPE. BEST 0-6KM BULK SHEAR IS CONFINED TO THE AREAS IN IMMEDIATE
PROXIMITY OF THE FRONT...WITH THE REST OF THE AREA 20-25KT OUT AHEAD
OF THE FRONT. THAT WILL LEAD TO THE STRONGEST STORMS OCCURRING TO
THE WEST OF THE AREA IN THE AFTERNOON AND THEN TRYING TO SHIFT EAST
INTO THE U.P. DURING THE EVENING. WITH MORE CLOUD COVER
TOMORROW...HAVE LIMITED THE TEMPS TO THE UPPER 70S WITH A FEW LOWER
80S IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. WIND GUSTS WILL ALSO
BE SIMILAR BUT SLIGHTLY LOWER AND ONCE AGAIN HAVE GUSTS IN THE 20-
25KT RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM EDT WED SEP 16 2015
MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON POPS/SEVERE
WX POTENTIAL THU NGT ASSOCIATED WITH COLD FROPA THAT WL BRING A
RETURN OF COOLER WX LATE THIS WEEK. ANOTHER CONCERN WL BE POPS LATE
FRI INTO SAT RELATED TO THE APRCH OF ANOTHER SHRTWV AND ITS
INTERACTION WITH STALLING FNT IN THE CENTRAL GREAT LKS. HI PRES AND
NEAR SEASONABLE TEMPS WL THEN DOMINATE LATE THIS WEEKEND.
THU NGT INTO FRI...LATEST MODEL GUIDANCE IS IN GOOD AGREEMENT
SHOWING SFC COLD FNT CROSSING THE UPR LKS THU NGT PASSING NEWBERRY
SOON AFTER 12Z FRI AND INTERACTING WITH WARM AIRMASS/PWAT NEAR 1.75
INCHES. SINCE NAM/GFS SDNGS INDICATE THE PRE FRONTAL AIRMASS WL BE
CAPPED...THE BULK OF SHOWERS/TS THAT FORM UNDER H7-5 LAPSE RATES AS
STEEP AS 7.5-8C/KM ARE LIKELY TO BE CLOSER TO THE SFC FNT. FCST
MUCAPES AS HI AS 1000-1500 J/KG...DEEP LYR SHEAR ABOUT 30-35KTS
ALONG THE FRONTAL BNDRY AND FCST DCAPES AS HI AS ABOUT 1000 J/KG
FOLLOWING THE WARM DAY ON THU SUPPORT THE MARGINAL/SLGT RISK FOR SVR
STORMS OUTLOOK FM SPC. RELATIVELY HI FRZG LVL FCST IN THE 12-14K
RANGE AND DEEP SATURATION SHOWN ON ESPECIALLY THE NAM FCST SDNGS AS
WELL AS PASSAGE OF STRONGER SHRTWV/HGT FALLS FARTHER TO THE N CLOSER
TO THE MAIN SHRTWV TRACK IN FAR NW ONTARIO ARE NEGATIVES. BEST CHC
FOR THE STRONGER STORMS SHOULD BE OVER THE W...WHERE THE ARRIVAL OF
THE FNT IN THE EVNG WOULD BE MORE IN SYNC WITH THE DAYTIME HEATING
CYCLE/HIER DCAPES. THE ARRIVAL OF DRIER/COOLER AIR BEHIND THE FROPA
WL BRING A DRYING TREND W-E LATER THU NGT INTO FRI...BUT SHALLOW
LLVL MSTR WITH INFLUX OF COOLER AIR BEHIND THE FNT/LO INVRN MAY LEAD
TO LINGERING LO CLDS INTO FRI MRNG...ESPECIALLY IN THE UPSLOPE AREAS
NEAR LK SUP.
FRI/SAT...ARRIVAL OF DRIER AIR/WEAK HI PRES RDG AND LLVL ACYC FLOW
WL RESULT IN A PERIOD OF DRY WX ON FRI AFTER LINGERING SHOWERS END
IN THE MRNG OVER THE E. BUT APRCH OF SHRTWV FM THE W IN MORE ZONAL
FLOW IN THE NRN PLAINS IS FCST TO CAUSE A SFC LO PRES TO DVLP ON FRI
AFTN IN IOWA ALONG STALLING COLD FNT STRETCHING FM THAT STATE INTO
LOWER MI UNDER MORE SW FLOW ALF ON NW FLANK OF UPR RDG PERSISTING IN
THE ERN CONUS. SOME OF THE MEDIUM RANGE GUIDANCE HAD INDICATED A
BAND OF PCPN ASSOCIATED WITH AXIS OF MID LVL FGEN WOULD IMPACT AT
LEAST PORTIONS OF THE CWA ON FRI AFTN WELL TO THE NE OF THIS
FEATURE...BUT DRYNESS OF THE MID LVL AIRMASS SHOWN ON THE 12Z NAM/
GFS FCST SDNGS SUG A DRY FCST IS WARRANTED AFTER THE FROPA SHOWERS
END OVER THE E IN THE MRNG. THERE ARE CONSIDERABLE MODEL DIFFERENCES
ON HOW QUICKLY AND TO WHAT EXTENT THE SFC LO IN IOWA WL INTENSIFY AS
IT TRACKS NE ON THE STALLED FNT INTO THE CENTRAL LKS. THE 12Z NAM IS
DEEPEST AND FARTHER W WITH THE TRACK OF THIS SYSTEM...SHOWING
WIDESPREAD RA IMPACTING ALL OF UPR MI THRU THE DAY ON SAT WITH
FAIRLY SHARP CYC NE FLOW LEADING TO A VERY CHILLY DAY AS WELL. THE
00Z CNDN/ECMWF RUNS ON THE OTHER HAND SHOWED A RELATIVELY WEAK SFC
LO MOVING QUICKLY TO THE NE...WITH LIGHTER PCPN ENDING SOON AFTER
12Z SAT. ALTHOUGH THE INCOMING SHRTWV IS RATHER IMPRESSIVE...WITH
00Z-12Z SAT H5 HGT FALLS FCST UP TO 100M EVEN WITH THE WEAKER ECWMF
FCST...AND MODEL TRENDS SUPPORT THE NAM FCST...PREFER TO FOLLOW A
COMPROMISE BTWN THE SOMEWHAT DEEPER 12Z GFS/CNDN/ECMWF MODEL FCSTS
AND THE WEAKER/FASTER SCENARIO SHOWN BY THE 00Z ECMWF/CNDN AND 09Z
SREF. NCEP GUIDANCE ALSO INDICATES A PREFERENCE FOR REJECTING THE
DEEPER 12Z NAM FCST. THE PREFERRED MODELS SHOW THE HIER CATEGORICAL/
LIKELY POPS OVER ALL BUT THE WRN CWA...WHERE CHC POPS APPEAR MORE
APPROPRIATE FARTHEST FM THE STALLED BNDRY TO THE SE. THIS SCENARIO
WL ALSO SUPPORT A STEADY DRYING TREND W-E ON SAT...WITH PCPN ENDING
OVER THE FAR E BY EARLY/MID AFTN.
SAT NGT INTO TUE...HI PRES TRAILING THE DEPARTING SFC LO PRES IS
FCST TO BUILD INTO THE LOWER GREAT LKS BY 12Z SUN...THE NE STATES AT
12Z MON AND THEN OVER THE CNDN MARITIMES ON TUE. DRY ACYC SW FLOW
ARND THIS FEATURE WL DOMINATE UPR MI DURING THIS TIME AND BRING A
PERIOD OF DRY WX. ALTHOUGH PWAT FALLING TOWARD 0.5 INCH AT 12Z SUN
WOULD SUPPORT SOME CHILLY OVERNGT LOWS...STEADY WSW FLOW ON THE NRN
FLANK OF HI PRES CENTER TO THE S MAY TEND TO LIMIT THE POTENTIAL FOR
COLDER TEMPS/FROST...ESPECIALLY OVER THE NW HALF UNDER TIGHTER PRES
GRADIENT. H85 TEMPS ARE FCST TO SLOWLY MODERATE THRU THIS TIME...
RISING FM ARND 8C ON SUN TO ARND 10C ON MON AND THEN 12C ON TUE...
SUPPORTING A SLOW WARMING TREND THAT WL FEATURE MEAN DAILY TEMPS
RISING FM NEAR NORMAL ON SUN TO AT LEAST A BIT ABOVE NORMAL AGAIN ON
MON/TUE.
TUE/WED...SHRTWV MOVING THRU ZONAL FLOW OVER CENTRAL CANADA IS FCST
TO DRAG A COLD FNT THRU THE UPR LKS LATE TUE/TUE NGT. SINCE THERE
ARE TIMING DIFFERENCES AND THE LONGER RANGE GUIDANCE HINTS MSTR
INFLOW WL BE SOMEWHAT LIMITED TO THE S OF SHARPER HGT FALLS TO THE
N...NO MORE THAN LO CHC POPS ARE NECESSARY AT THIS POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 231 AM EDT THU SEP 17 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH GUSTY
SOUTH-SOUTHWESTERLY WINDS. THE GUSTY WINDS WILL WEAKEN SLIGHTLY
OVERNIGHT AND LEAD TO THE POTENTIAL FOR LLWS AT ALL THREE SITES.
THOUGH KIWD WOULD HAVE THE BEST CHANCE FOR THE WINDS TO STAY UP AND
HAVE LEFT LLWS OUT OF IWD...BUT CMX AND SAW WILL HAVE THEM
OVERNIGHT. A DISTURBANCE WILL PUSH ACROSS WESTERN LAKE SUPERIOR LATE
TONIGHT AND IT COULD BRUSH KIWD. THEN...SHOWERS WILL INCREASE FROM
WEST TO EAST DURING THE AFTERNOON AND EVENING AS A COLD FRONT SWEEPS
ACROSS THE AREA. EXPECT DETERIORATING CONDITIONS TO MVFR CIGS FOR
ALL SITES LATE IN THE AFTERNOON AND MVFR CIGS WILL BE CLOSE TO CMX
AT THAT TIME AS WELL. THE MVFR CONDITIONS WILL LAST INTO FRI EVENING
AT ALL SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 306 PM EDT WED SEP 16 2015
GUSTY SOUTHERLY WINDS WILL REMAIN IN PLACE OVER THE NEXT 24-30
HOURS AS THE UPPER GREAT LAKES REGION IS BETWEEN HIGH PRESSURE IN
THE MID ATLANTIC STATES AND A COUPLE LOWS THAT WILL BE MOVING
NORTHEAST ACROSS ONTARIO. THESE SOUTHERLY WINDS WILL GENERALLY BE
IN THE 15-25KT RANGE...BUT WITH VERY STRONG WINDS JUST ABOVE THE
SURFACE...COULD SEE SOME STRONGER GUSTS TO 30KTS AT TIMES OVER
EASTERN LAKE SUPERIOR. A COLD FRONT MOVING EAST ACROSS LAKE
SUPERIOR ON THURSDAY NIGHT WILL SHIFT WINDS TO THE NORTHWEST UP TO
25KTS. THE WINDS WILL DIMINISH THROUGH THE DAY ON FRIDAY AS A HIGH
PRESSURE RIDGE QUICKLY BUILDS INTO THE AREA. ON FRIDAY NIGHT...A
SURFACE LOW WILL DEVELOP ALONG THE COLD FRONT THAT MOVED THROUGH ON
THURSDAY NIGHT AND MOVE THROUGH LOWER MICHIGAN. THIS WILL SHIFT
WINDS MORE OUT OF THE NORTHERLY DIRECTION UP TO 25 KNOTS LATE
FRIDAY NIGHT INTO SATURDAY MORNING. A LARGE HIGH PRESSURE RIDGE
WILL BUILD OVER THE GREAT LAKES REGION SATURDAY NIGHT AND REMAIN
INTO MONDAY AND KEEP WINDS BELOW 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
125 AM EDT THU SEP 17 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED TO OUR NORTH WILL WEAKEN GRADUALLY THROUGH
THE REMAINDER OF THE WEEK. A TROUGH OF LOW PRESSURE WILL RESIDE
ALONG THE COAST. THERE WILL BE A RISK FOR SHOWERS...PRIMARILY
ALONG THE COAST INTO THE WEEKEND. A COLD FRONT WILL DROP SOUTH OF
THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 945 PM WEDNESDAY...SFC HIGH CENTERED OVER LAND...THE VA
CAPES ATTM...AND WILL CONTINUE TO FUNNEL RELATIVELY DRY AIR ACROSS
THE FA AT THE LOW LEVELS...WITH MUCH OF IT FELT ACROSS THE ILM NC
CWA. THIS HAS KEPT THE LOW AND MID LEVELS RELATIVELY DRY WITH ONLY
CI/CS...OCCASIONALLY OPAQUE...PUSHING ACROSS THE ENTIRE ILM CWA.
LATEST VARIOUS MODEL TIME HEIGHT DISPLAYS ACROSS THE FA SUPPORT
THIS OCCURRING THRU THE EVENING AND OVERNIGHT. THE FLY IN THE
OINTMENT...IS THE TROUGHINESS IN THE MID AND UPPER LEVELS ACROSS
THE NE GULF OF MEXICO EXTENDING INTO THE SOUTHEAST UNITED STATES.
MODELS DO INDICATE THIS FEATURE DRIFTING TOWARD THE NE- ENE
OVERNIGHT. THIS WILL RESULT IN SOME SHARPENING OF THE INVERTED SFC
TROF OFF THE SOUTHEAST U.S. COAST OVERNIGHT INTO THE SHORT TERM
PERIOD. IN ADDITION...LOOK FOR MOISTURE TO INCREASE AT ALL LEVELS
MAINLY ACROSS THE ILM SC CWA...MAINLY WELL SOUTH AND EAST OF THE
I-95 CORRIDOR TO THE SC COAST. HAVE CONCENTRATED THE INCREASE IN
POPS MAINLY ACROSS THE COASTAL COUNTIES OF THE ILM SC CWA...AND
MAINLY AFTER MIDNIGHT. THE LATEST RAP MODEL RUN HOLDS OFF THE
DEEPER MOISTURE FROM REACHING THE ILM NC COASTAL CWA OVERNIGHT.
HAVE BASICALLY KEPT A DRY BIAS ACROSS THE ILM NC CWA...WITH ONLY
AN ISOLATED -SHRA POSSIBLE ALONG THE IMMEDIATE NC COAST FROM
ROUGHLY CAPE FEAR SOUTHWARD OCCURRING AROUND DAYBREAK THU. SOME
MASSAGING OF THE MIN TEMPS...SLIGHTLY LOWER BY A DEGREE OR 2
MAINLY ACROSS THE ILM NC CWA...AND ACROSS THE NW PORTIONS OF THE
ILM SC CWA.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A COASTAL TROUGH OR PERHAPS EVEN A VERY
MEEKLY CLOSED OFF WILL VERY SLOWLY TAKE SHAPE OVER THE COURSE OF THE
SHORT TERM PERIOD. THERE WILL ALSO BE A TROUGHINESS IN THE MID
LEVELS RUNNING FROM THE FL BIG BEND TO THE OUTER BANKS OF NC.
TOGETHER THESE WILL CHANNEL FAIRLY DEEP MOISTURE UP THE COAST.
MODELS ARE HAVING DIFFICULTY RESOLVING THE WESTWARD EXTENT OF THE
MOISTURE AND THUS RAIN CHANCES. ADVECTING PRECIPITATION TOO FAR AND
TOO FAST IS A COMMON MODEL ERROR SO THE HIGH POPS AND QPF OF THE GFS
HAVE BEEN DOWNPLAYED IN FAVOR OF THE MUCH MORE CONSERVATIVE ECMWF.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...SATURDAY WILL BEGIN WITH A TROUGH SFC-
ALOFT MOVING SLOWLY EASTWARD ACROSS SC-GA-FL. THE TROUGH WILL SLOW
BY SUNDAY AND LINGER OFF THE SOUTHEAST CONUS INTO TUESDAY. THERE
WILL GOOD POTENTIAL FOR SHOWERS TO AFFECT THE CWA SATURDAY AS DEEP
MOISTURE CIRCULATES ONSHORE AND PRECIPITABLE WATER VALUES EXCEED
TWO INCHES ACROSS THE EASTERN HALF OF THE CWA. THE MOISTURE
GRADIENT WILL BE SOMEWHAT TIGHT HOWEVER...SO IF THE TROUGH REMAINS
FAR ENOUGH OFFSHORE...PRECIP CHANCES WOULD BE SIGNIFICANTLY LOWER.
FOR SUNDAY-WEDNESDAY...THE FORECAST UNCERTAINTY INCREASES AS THE
GFS AND ECMWF DIFFER ON HOW THIS TROUGH WILL INTERACT WITH ANOTHER
SHARP TROUGH APPROACHING FROM THE WEST. THOUGH BOTH MODELS BRING
DRIER MID-LEVEL AIR ACROSS THE AREA ON SUNDAY...THE ECMWF DRAWS
THE TROUGH AND ASSOCIATED MOISTURE WESTWARD EARLY NEXT WEEK WHILE
THE GFS KEEPS IT FURTHER OFFSHORE. DUE TO THIS UNCERTAINTY...PLAN
TO INCLUDE AT LEAST A SMALL POP EACH DAY EXCEPT SUNDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...A COASTAL TROUGH WILL SLOWLY MOVE NORTH DURING THE
NEXT 24 HOURS. LOOK FOR MAINLY A MID CLOUD CEILING OVERNIGHT...
INTERMITTENTLY A VFR STRATOCUMULUS CEILING. TIME HEIGHT SECTIONS
SHOW CEILINGS SLOWLY LOWERING OVERNIGHT...WITH A 4K DECK OVER MUCH
OF THE COAST BY MORNING. THINK THERE WILL BE ENOUGH ONSHORE
MOISTURE TO PRODUCE WEAK SHOWERS AT THE MYRTLES. THE PRECIP MAY
MAKE IT AS FAR NORTH AS ILM...HOWEVER IT WILL TAKE QUITE A FEW
HOURS LONGER. INLAND TERMINALS WILL REMAIN VFR WITH NO PRECIP
EXPECTED THROUGH THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...COASTAL SHOWERS ARE POSSIBLE THROUGH SATURDAY
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM WEDNESDAY...SFC HIGH TO REMAIN CENTERED ACROSS THE
VA CAPES THIS EVENING AND OVERNIGHT...AND WILL RIDGE SW ACROSS THE
CENTRAL CAROLINAS INTO DAYTIME THU. AT THE SAME TIME...AN
INVERTED SFC TROF WILL FURTHER DEVELOP AND EXTEND NE ACROSS THE
OFFSHORE WATERS OFF THE CAROLINAS...NEARLY PARALLEL TO THE
CAROLINAS COASTLINES. SOME MODELS INDICATE A TIGHTENING OF THE SFC
PG IN THE VICINITY OF THE ILM SC WATERS AND THUS WILL GO AHEAD AND
INDICATE A SOLID 15 KT...TO POSSIBLY 20 KT ACROSS THE
SOUTHERNMOST PORTIONS OF THE ILM COASTAL WATERS.
SIGNIFICANT SEAS WILL RUN AROUND 3 FT FOR THE ILM NC WATERS...AND
POSSIBLY BUILD TO A SOLID 4 FT FOR THE SOUTHERNMOST ILM SC WATERS
DURING THE OVERNIGHT. WITH THIS PERSISTENT ONSHORE FLOW...A
SEMI-GROUND SWELL SO TO SPEAK...WILL AFFECT THE AREA WATERS
RUNNING AT 6 TO 7 SECOND PERIODS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...THE LARGE AREA OF HIGH PRESSURE THAT HAS
BEEN BRINGING NORTHEASTERLY WINDS FOR A WHILE NOW WILL GRADUALLY
WEAKEN AND DRIFT EASTWARD THROUGH THE PERIOD. MEANWHILE AN UPPER
LEVEL TROUGH LINING UP ALONG THE COAST WILL INDUCE A SURFACE WAVE
OF LOW PRESSURE THAT MAY EVEN TRY TO FORM A WEAKLY CLOSED LOW.
THIS TROUGHINESS WILL OFFSET THE WEAKENING OF THE HIGH TO KEEP
WIND SPEEDS FAIRLY STEADY IN THE 10-15KT RANGE OVER MOST ZONES AND
SOME GUSTS TO 20 ARE POSSIBLE LATE IN THE PERIOD AS LOW LEVEL
JETTING INCREASES SOME. A FEW 4 FT SEAS MAY APPEAR ALONG THE
EASTWARD EXTREME OF SOME OF THE MARINE ZONES.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...SURFACE LOW PRESSURE IS EXPECTED TO
DEVELOP OFF THE SOUTH CAROLINA COAST SATURDAY AND LINGER OFF THE
SOUTHEAST COAST OF THE CONUS THROUGH MONDAY. GIVEN THE PROXIMITY
OF THE LOW...THE AREA WATERS SHOULD REMAIN IN A GENERAL NORTHEAST
FLOW IN THE 15-20 KNOT RANGE. EXPECT SEAS OF 3-4 FEET THROUGH THE
PERIOD...CLOSER TO 2 FEET IN THE SHELTERED WATERS SOUTH OF CAPE
FEAR...BUT WINDS AND SEAS LOOK TO TREND HIGHER SUNDAY NIGHT AND
MONDAY AS HIGH PRESSURE BUILDS OVER THE CAROLINAS AND THE PRESSURE
GRADIENT INTENSIFIES OVER THE WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...CRM
AVIATION...RJD/DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1239 AM CDT THU SEP 17 2015
.UPDATE...
ISSUED AT 1235 AM CDT THU SEP 17 2015
A MINOR UPDATE TO ACCOUNT FOR LATEST TRENDS. THE TROUGH AXIS
CURRENTLY BISECTS THE STATE. EAST OF THE AXIS SHOWERS AND
THUNDERSTORMS CONTINUE TO DEVELOP. WEST OF THE AXIS GUSTY
NORTHWEST WINDS AND LOWER CLOUDS WERE MOVING IN. UPDATED THE
LATEST PRECIPITATION FORECAST BASED ON RADAR TRENDS AND HIGH
RESOLUTION SHORT TERM MODELS.
UPDATE ISSUED AT 1027 PM CDT WED SEP 16 2015
AS OF 330 UTC...ELEVATED CONVECTION ASSOCIATED WITH A WARM FRONT
ACROSS THE I-94 CORRIDOR IN A LOW CAPE...HIGH SHEAR ENVIRONMENT
HAS DISPLAYED LOW-TOPPED SUPERCELLULAR CHARACTERISTICS OVER THE
PAST 1-2 HOURS. THIS INCLUDES THE STORM THAT IMPACTED THE
DICKINSON AREA EARLIER THIS EVENING. THUS...EXPECT A MARGINAL
THREAT FOR SEVERE HAIL AND WIND GUSTS TO PERSIST THROUGH 06-07
UTC ACROSS THE I-94 THROUGH ND HIGHWAY 200 CORRIDORS.
UPDATE ISSUED AT 651 PM CDT WED SEP 16 2015
NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE AS A TIME LAGGED
ENSEMBLE OF THE 21-23 UTC HRRR ITERATIONS MATCHES WELL WITH
ONGOING RADAR TRENDS THROUGH 00 UTC AHEAD OF MULTIPLE SHORTWAVES
ACROSS EASTERN MONTANA INTO NORTHWEST SOUTH DAKOTA. GIVEN WEAK
INSTABILITY...THE PREDOMINANT MODE OF PRECIPITATION IS EXPECTED TO
BE RAIN SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. SEVERE WEATHER
IS NOT EXPECTED.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 216 PM CDT WED SEP 16 2015
A STRONG UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TO WESTERN AND CENTRAL NORTH DAKOTA TONIGHT.
FOLLOWED BY COOLER TEMPERATURES AND BREEZY CONDITIONS ON THURSDAY.
CURRENTLY...SHORTWAVE TROUGH FROM CENTRAL MONTANA INTO WESTERN
WYOMING IS LIFTING NORTHEAST THROUGH THE WESTERN U.S. UPPER LEVEL
LONGWAVE TROUGH. LEADING EDGE OF SHOWER ACTIVITY EXTENDS TO AROUND
WOLF POINT AND MILES CITY IN EASTERN MONTANA. SURFACE LOW PRESSURE
WAS SITUATED OVER NORTHEAST WYOMING WITH AND INCREASING SOUTHEAST
SURFACE FLOW OVER SOUTHWEST NORTH DAKOTA...AND AN INCREASING EAST
TO NORTHEAST SURFACE FLOW ELSEWHERE.
LATE THIS AFTERNOON AND TONIGHT. EXPECT SHOWER AND THUNDERSTORM
ACTIVITY TO INCREASE OVER EASTERN MONTANA AND WESTERN NORTH
DAKOTA LATE THIS AFTERNOON AS THE SURFACE LOW TRACKS INTO
NORTHWEST NORTH DAKOTA. THERE IS SOME WEAK INSTABILITY ALOFT LATE
THIS AFTERNOON INTO EARLY THIS EVENING OVER WESTERN NORTH DAKOTA.
BUT LOW LEVEL INHIBITION REMAINS STRONG. WE DO SEE INCREASING
LAPSE RATES LATER THIS AFTERNOON AND WITH THE STRONG DYNAMIC WAVE
LIFTING THROUGH THE AREA...AN ISOLATED SEVERE WIND GUST COULD BE
POSSIBLE. BUT GENERALLY THINK SCATTERED TO NUMEROUS SHOWERS AND
EMBEDDED THUNDERSTORMS LIFTING FROM WESTERN INTO NORTH CENTRAL
NORTH DAKOTA ALONG AND NORTH OF THE SURFACE LOW THAT TRACKS ACROSS
THE NORTH DAKOTA/SOUTH DAKOTA BORDER.
ON THURSDAY...SCATTERED SHOWERS WILL REMAIN ALONG THE
INTERNATIONAL BORDER...CLOSER TO THE COLD AIR ASSOCIATED WITH THE
UPPER LEVEL TROUGH. FARTHER SOUTH...PERHAPS A LINGERING SHOWER
ACROSS THE SOUTH CENTRAL...BUT EXPECT INCREASING SUBSIDENCE
THROUGH THE DAY WITH HIGH PRESSURE BUILDING OVER THE AREA. BREEZY
CONDITIONS DURING THE MORNING AND EARLY AFTERNOON WITH DIMINISHING
WINDS MID TO LATE AFTERNOON AS THE SURFACE HIGH BUILDS OVER THE
STATE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 216 PM CDT WED SEP 16 2015
SHOWERS AND THUNDERSTORMS HIGHLIGHT THE FORECAST FOR THURSDAY
NIGHT AND FRIDAY...WHILE DRY AND SEASONABLE CONDITIONS BECOME THE
FOCUS FOR THE WEEKEND.
THURSDAY NIGHT...A DEPARTING SHORTWAVE WILL KEEP AN ISOLATED SHOWER
OR TWO POSSIBLE IN THE NORTHEAST PART OF THE COUNTY WARNING AREA...
WITH A BRIEF PERIOD OF CLEARING ACROSS THE STATE FROM WEST TO EAST.
EARLY FRIDAY MORNING...THE NEXT SHORTWAVE WILL MOVE INTO SOUTH
DAKOTA FROM WYOMING...INCREASING CLOUD COVER AND PRECIPITATION
CHANCES OVER OUR SOUTHERN ZONES. 12Z NAM/GFS MODEL RUNS SUGGEST THE
BEST CHANCES FOR SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM WILL
RESIDE OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA...MAINLY ALONG
AND SOUTH OF INTERSTATE 94 FRIDAY MORNING AND INTO THE EARLY
AFTERNOON. MEAGER INSTABILITY FROM MODEL FORECAST SOUNDINGS SHOULD
KEEP THUNDERSTORM COVERAGE AND STRENGTH TO A MINIMUM. HIGH
TEMPERATURES ON FRIDAY WILL REMAIN ON THE COOL SIDE...GENERALLY IN
THE 60S.
SATURDAY WILL FEATURE DRY AND SEASONABLE CONDITIONS WITH HIGHS IN
THE LOWER 70S. PLEASANT WEATHER WILL CONTINUE THROUGH MONDAY...WITH
TEMPERATURES WARMING SLIGHTLY EACH DAY. THE NEXT CHANCES FOR
PRECIPITATION WILL BE OVERNIGHT MONDAY AND INTO TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1235 AM CDT THU SEP 17 2015
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE ACROSS CENTRAL
AND EASTERN NORTH DAKOTA LATE TONIGHT. CEILINGS ARE EXPECTED TO
LOWER TO MVFR AT KISN/KDIK/KMOT TONIGHT. KJMS AND KBIS ARE MORE
UNCERTAIN REGARDING POTENTIAL STRATUS IMPACTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...TWH
LONG TERM...ZH
AVIATION...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS PENDLETON OR
1044 PM PDT WED SEP 16 2015
UPDATED AVIATION DISCUSSION
.UPDATE...A WEAK WAVE IS MOVING ACROSS THE EASTERN PART OF THE
AREA AND SHOULD EXIT IN THE NEXT FEW HOURS. THIS WAVE HAS BROUGHT
VERY MODEST AMOUNTS OF RAIN IN SOME LOCATIONS...UP TO A COUPLE OF
HUNDREDTHS OF AN INCH AT MOST, WHILE MUCH OF THE AREA REMAINED
DRY. SATELLITE IMAGERY SHOW ANOTHER STRONGER WAVE MOVING SOUTH
ALONG THE NORTHERN WASHINGTON AREA AND SHOULD ARRIVE IN OUR AREA
LATER NIGHT AND TOMORROW MORNING WITH MORE GENEROUS AMOUNTS OF
RAIN LIKELY. CONSIDERED DROPPING POPS THROUGH MIDNIGHT BUT THE
SHORT RANGE HRRR MODEL SHOWS AN INCREASE IN ACTIVITY IN THE NEXT
FEW HOURS IN CENTRAL OREGON AND THEN MOVING THROUGH THE AREA, SO
LEFT POPS AS IS. RADAR DOES SHOW A SLOW GENERAL UPWARD TREND IN
THE SHOWER ACTIVITY. MADE SOME WIND ADJUSTMENTS THROUGH THE REST
OF THE NIGHT BUT NOTHING VERY SIGNIFICANT. ALSO MADE A FEW
TEMPERATURE ADJUSTMENTS UPWARD DUE TO THE HEAVY CLOUD COVER AND
SLIGHTLY STRONGER WINDS. FORECAST UPDATE ALREADY OUT. PERRY
&&
.AVIATION...06Z TAFS...VFR CONDITIONS WILL BE PREVALENT FOR THE NEXT
24 HOURS. ONE WAVE IS EXITING THE AREA WITH LIGHT SHOWERS OVER THE
EASTERN PORTIONS OF THE AREA. ANOTHER WAVE IS POISED TO MOVE INTO
THE AREA IN THE NEXT FEW HOURS WITH STRATIFORM RAIN INCREASING FROM
CENTRAL OREGON NORTHEAST ACROSS THE AREA FROM 07Z TO 12Z. RAIN WILL
BE MODERATE AT TIMES AND MVFR CEILINGS AND VISIBILITIES WILL BE
POSSIBLE AT ALL TAF SITES, ESPECIALLY KDLS AND KBDN. RAIN WILL TAPER
OFF AND END FROM 16Z TO 20Z. SKIES WILL BE BROKEN TO OVERCAST AT
4000-8000 FEET THROUGH 00Z THEN BECOMING SCATTERED TO BROKEN ABOVE
6000 FEET AFTER THAT. WINDS WILL REMAIN BELOW 15 KTS TONIGHT THEN
INCREASE TO 10 TO 20 KTS WITH HIGHER GUSTS FROM 16Z-03Z. WINDS WILL
DROP BELOW 12 KTS AFTER 03Z. PERRY
&&
.PREV DISCUSSION... /ISSUED 415 PM PDT WED SEP 16 2015/
SHORT TERM...TONIGHT THROUGH SATURDAY...A BROAD AND DEEP UPPER
LEVEL TROUGH REMAINS OVER THE WESTERN US. THERE ARE A COUPLE OF
SHORTWAVES IN THE PATTERN THAT WILL IMPACT THE AREA. THE FIRST IS
COMING INTO SOUTHWEST OREGON THAT WILL SPREAD SOME PRECIPITATION
INTO CENTRAL OREGON LATE TODAY AND THEN OVER THE REST OF THE
FORECAST AREA OVERNIGHT. THE SECOND IS SLIDING DOWN THE COAST OF
BRITISH COLUMBIA AND WILL MOVE ACROSS THE FORECAST AREA ON THURSDAY
KEEPING US UNDER A HIGH THREAT OF PRECIPITATION. PRECIPITATION
AMOUNTS WILL RANGE FROM A HALF INCH OR MORE IN THE MOUNTAINS TO A
TENTH TO ONE QUARTER OF AN INCH IN THE BASIN THROUGH THURSDAY
EVENING. FOLLOWING THE PASSAGE OF THIS SECOND SYSTEM WITH WEATHER
PATTERN WILL CHANGE. THE TROUGH OVER THE REGION NOW WILL MOVE OFF TO
THE EAST PLACING US UNDER A DRY WESTERLY FLOW THROUGH SATURDAY. WE
WILL SEE TEMPERATURES BEGIN TO WARM ON FRIDAY AND SATURDAY.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY AFTERNOON...A
MID/UPPER LEVEL SHORT WAVE WILL BRING INCREASING MOISTURE ALONG THE
EAST SLOPES OF THE CENTRAL WASHINGTON CASCADE SATURDAY NIGHT THUS
INTRODUCING A LOW CHANCE OF SHOWERS NEAR THE WASHINGTON CASCADE
CRESTS SATURDAY NIGHT INTO SUNDAY MORNING. THE SHORT WAVE PUSHES A
COLD FRONT THROUGH THE REGION ON MONDAY. THE SHORT WAVE AND COLD
FRONT WILL GIVE THE EAST SLOPES OF THE WASHINGTON CASCADES SHOWERS
LIKELY MONDAY AFTERNOON AND MONDAY EVENING AND JUST A SLIGHT CHANCE
OF SHOWERS ALONG THE EAST SLOPES OF THE CENTRAL AND NORTHERN OREGON
CASCADES AND IN THE NORTHERN BLUE MOUNTAINS AND THE WALLOWA
MOUNTAINS ON MONDAY. OTHERWISE, FLOW ALOFT ASSOCIATED WITH THE SHORT
WAVE WILL BE WESTERLY THUS PRODUCING DOWNSLOPE WINDS AND SINKING AIR
MOTION FOR DRY CONDITIONS ELSEWHERE IN FORECAST AREA FOR A DRY COLD
FRONT AT LOWER ELEVATIONS. THE SHORT WAVE WILL EXIT THE REGION LATE
MONDAY NIGHT WITH AN UPSTREAM FLAT RIDGE OF HIGH PRESSURE MOVING
INTO THE PACIFIC NORTHWEST FOR TUESDAY THROUGH WEDNESDAY FOR DRY
CONDITIONS PERSISTING THROUGH THE EXTENDED PERIOD. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 51 65 47 72 / 60 70 10 0
ALW 54 67 50 74 / 60 70 20 0
PSC 53 71 49 77 / 60 70 10 0
YKM 45 68 43 75 / 60 70 10 0
HRI 53 69 48 75 / 60 70 10 0
ELN 44 66 42 73 / 60 70 10 10
RDM 39 61 38 73 / 60 70 10 0
LGD 44 59 42 69 / 60 80 20 10
GCD 44 62 40 73 / 70 90 10 0
DLS 52 70 50 77 / 60 70 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/99/83
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
334 AM CDT THU SEP 17 2015
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 334 AM CDT THU SEP 17 2015
COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING
WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL.
UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE
NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE
EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR
WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS
AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY
NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD
THROUGH THE DAY.
SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE
RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT
AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS
CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z
FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE
ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST
CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY
EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES
ON SATURDAY.
.LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY)
ISSUED AT 334 AM CDT THU SEP 17 2015
SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE
FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH
SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF
THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS
A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON
THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT
BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER
STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW
WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED
AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS
GIVEN BY SUPERBLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1223 AM CDT THU SEP 17 2015
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE DAY
THURSDAY. THERE WILL ALSO BE SCATTERED SHOWERS AND THUNDERSTORMS
MOVING ACROSS THE REGION TONIGHT AND INTO THE MORNING ON THURSDAY.
ISOLATED STRONG WIND GUSTS TO 50 KTS ARE POSSIBLE WITH THESE
STORMS. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE
NORTHWEST AND INCREASE INTO THE 15 TO 30 KT RANGE THURSDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...WISE
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1231 AM CDT THU SEP 17 2015
.UPDATE...
ISSUED AT 1228 AM CDT THU SEP 17 2015
BROKEN LINE OF SHOWERS AND STORMS MOVING EASTWARD ACROSS CENTRAL
SD AND WILL BE INTO THE JAMES VALLEY SOON. SOME OF THE STRONGER
CORES ARE PRODUCING GUSTS OVER 50 MPH AND EVEN A 60 MPH GUST AT
PRESHO. ALSO SEEING A FEW WEAK HEAT BURSTS WITH TEMP RISES FROM 5
TO 10 DEGREES. HAVE UPDATED POPS TO INCREASE PRECIP CHANCES
THROUGH THE NIGHT AS THIS ACTIVITY MOVES EASTWARD. HRRR SEEMS TO
HAVE A GOOD HANDLE ON THIS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 314 PM CDT WED SEP 16 2015
WEAK CONVECTION OVER CLEAR LAKE WILL CONTINUE TO PUSH OFF INTO
MINNESOTA THIS AFTERNOON. HRRR SHOWS ADDITIONAL WEAK/SCATTERED
REDEVELOPMENT...THE DISORGANIZATION LIKELY OWING TO A LACK OF STRONG
FORCING ALOFT. THIS AREA MAY EXPERIENCE SOME ADDITIONAL MORE
ORGANIZED ELEVATED CONVECTION AS A LOW LEVEL JET DEVELOPS THIS
EVENING...HOWEVER THE MAIN FOCUS OF THE JET WILL SHIFT EAST OF THE
CWA. A WAVE ALOFT WILL PROVIDE FOR INCREASING MID LEVEL MOISTURE
WEST RIVER...SHIFTING EAST OVERNIGHT. SOUNDINGS ARE DRY BELOW
10KFT...WITH VERY LIMITED INSTABILITY ALOFT...SUGGESTING SCATTERED
VERY LIGHT SHOWERS WITH THE OCCASIONAL LIGHTING STRIKE. CANADIAN
HIGH PRESSURE NOSING INTO THE CWA THURSDAY WILL ALLOW FOR MORE
AVERAGE DAYTIME TEMPERATURES. MODELS CONTINUE TO GENERATE A RATHER
PROMINENT QPF BULLSEYE WEST RIVER INTO CENTRAL COUNTIES FRIDAY IN
THE VICINITY OF AN INVERTED TROF...WITH FAVORABLE PLACEMENT OF A
SHARED ENERGY AREA AND Q VECTOR BULLSEYE. TO THE EAST...WE WILL SEE
A DRY NORTHEAST FETCH...WHICH WILL LIMIT QPF/POPS. 850MB
TEMPERATURES WILL HAVE BOTTOMED OUT AROUND +5C BY THAT POINT...SO
ANTICIPATE MUCH OF THE FORECAST AREA WILL STRUGGLE TO TOP 60F.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 314 PM CDT WED SEP 16 2015
HIGH PRESSURE WILL BE CENTERED OVER NEBRASKA WHEN THE PERIOD
BEGINS...THEN GETS QUICKLY PUSHED EASTWARD AHEAD OF AN APPROACHING
TROUGH SATURDAY NIGHT. THE TROUGH/FRONT WILL SLOWLY STRENGTHEN AND
LOOKS TO FINALLY TRACK ACROSS THE CWA TUESDAY AND
WEDNESDAY...BECOMING THE FOCUS FOR POTENTIAL PRECIPITATION. BEST
CHANCES WILL BE ACROSS THE EASTERN PART OF THE CWA WHERE SOME
INSTABILITY IS NOTED IN THE MODELS. NOT MUCH IN THE WAY OF UPPER
LEVEL ENERGY...SO WILL KEEP POPS LOW FOR THE TIME BEING.
WILL SEE A GRADUAL WARMING TREND DURING THE FIRST HALF OF THE PERIOD
WITH HIGHS IN THE UPPER 60S AND LOWER 70S SATURDAY...MAINLY IN THE
70S ON SUNDAY...AND IN THE UPPER 70S TO MID 80S MONDAY. HIGHS IN THE
70S TO AROUND 80 WILL BE COMMON TUESDAY AND WEDNESDAY...DEPENDING ON
CLOUD COVER AND POSSIBLE PRECIPITATION. OVERNIGHT LOWS WILL BE IN
THE UPPER 40S TO MID 50S THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1223 AM CDT THU SEP 17 2015
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE DAY
THURSDAY. THERE WILL ALSO BE SCATTERED SHOWERS AND THUNDERSTORMS
MOVING ACROSS THE REGION TONIGHT AND INTO THE MORNING ON THURSDAY.
ISOLATED STRONG WIND GUSTS TO 50 KTS ARE POSSIBLE WITH THESE
STORMS. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE
NORTHWEST AND INCREASE INTO THE 15 TO 30 KT RANGE THURSDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...WISE
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1225 AM CDT THU SEP 17 2015
.UPDATE...
ISSUED AT 1032 PM CDT WED SEP 16 2015
NO CHANGES PLANNED. FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 314 PM CDT WED SEP 16 2015
WEAK CONVECTION OVER CLEAR LAKE WILL CONTINUE TO PUSH OFF INTO
MINNESOTA THIS AFTERNOON. HRRR SHOWS ADDITIONAL WEAK/SCATTERED
REDEVELOPMENT...THE DISORGANIZATION LIKELY OWING TO A LACK OF STRONG
FORCING ALOFT. THIS AREA MAY EXPERIENCE SOME ADDITIONAL MORE
ORGANIZED ELEVATED CONVECTION AS A LOW LEVEL JET DEVELOPS THIS
EVENING...HOWEVER THE MAIN FOCUS OF THE JET WILL SHIFT EAST OF THE
CWA. A WAVE ALOFT WILL PROVIDE FOR INCREASING MID LEVEL MOISTURE
WEST RIVER...SHIFTING EAST OVERNIGHT. SOUNDINGS ARE DRY BELOW
10KFT...WITH VERY LIMITED INSTABILITY ALOFT...SUGGESTING SCATTERED
VERY LIGHT SHOWERS WITH THE OCCASIONAL LIGHTING STRIKE. CANADIAN
HIGH PRESSURE NOSING INTO THE CWA THURSDAY WILL ALLOW FOR MORE
AVERAGE DAYTIME TEMPERATURES. MODELS CONTINUE TO GENERATE A RATHER
PROMINENT QPF BULLSEYE WEST RIVER INTO CENTRAL COUNTIES FRIDAY IN
THE VICINITY OF AN INVERTED TROF...WITH FAVORABLE PLACEMENT OF A
SHARED ENERGY AREA AND Q VECTOR BULLSEYE. TO THE EAST...WE WILL SEE
A DRY NORTHEAST FETCH...WHICH WILL LIMIT QPF/POPS. 850MB
TEMPERATURES WILL HAVE BOTTOMED OUT AROUND +5C BY THAT POINT...SO
ANTICIPATE MUCH OF THE FORECAST AREA WILL STRUGGLE TO TOP 60F.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 314 PM CDT WED SEP 16 2015
HIGH PRESSURE WILL BE CENTERED OVER NEBRASKA WHEN THE PERIOD
BEGINS...THEN GETS QUICKLY PUSHED EASTWARD AHEAD OF AN APPROACHING
TROUGH SATURDAY NIGHT. THE TROUGH/FRONT WILL SLOWLY STRENGTHEN AND
LOOKS TO FINALLY TRACK ACROSS THE CWA TUESDAY AND
WEDNESDAY...BECOMING THE FOCUS FOR POTENTIAL PRECIPITATION. BEST
CHANCES WILL BE ACROSS THE EASTERN PART OF THE CWA WHERE SOME
INSTABILITY IS NOTED IN THE MODELS. NOT MUCH IN THE WAY OF UPPER
LEVEL ENERGY...SO WILL KEEP POPS LOW FOR THE TIME BEING.
WILL SEE A GRADUAL WARMING TREND DURING THE FIRST HALF OF THE PERIOD
WITH HIGHS IN THE UPPER 60S AND LOWER 70S SATURDAY...MAINLY IN THE
70S ON SUNDAY...AND IN THE UPPER 70S TO MID 80S MONDAY. HIGHS IN THE
70S TO AROUND 80 WILL BE COMMON TUESDAY AND WEDNESDAY...DEPENDING ON
CLOUD COVER AND POSSIBLE PRECIPITATION. OVERNIGHT LOWS WILL BE IN
THE UPPER 40S TO MID 50S THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1223 AM CDT THU SEP 17 2015
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE DAY
THURSDAY. THERE WILL ALSO BE SCATTERED SHOWERS AND THUNDERSTORMS
MOVING ACROSS THE REGION TONIGHT AND INTO THE MORNING ON THURSDAY.
ISOLATED STRONG WIND GUSTS TO 50 KTS ARE POSSIBLE WITH THESE
STORMS. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE
NORTHWEST AND INCREASE INTO THE 15 TO 30 KT RANGE THURSDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...WISE
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
328 AM CDT THU SEP 17 2015
.SHORT TERM...
(Today and Tonight)
Very little change today from what we experienced yesterday. The
upper level ridge will remain parked over the area, and may
strengthen just a tad. 850mb temperatures also warm a degree or so,
so have gone with highs of a degree or two warmer generally. Low
clouds have already begun making their way into the Concho Valley
early this morning, and so we will likely see another day with a
field of stratocumulus or cumulus clouds across much of the area.
The HRRR tries to produce a few showers in our southeastern
counties, but with the upper level high strengthening a bit, there
shouldn`t be enough coverage to mention anything in the forecast, if
they even develop. We will see another mild night with lows in the
upper 60s to lower 70s and southerly winds of 5 to 15 mph.
20
.LONG TERM...
(Friday through Wednesday)
Above normal temperatures are forecast across West Central Texas on
Friday as an upper level ridge remains centered across Central
Texas. Highs will generally be in the mid to upper 90s, with
overnight lows mainly in the lower 70s.
An upper level trough will move across the Plains on Friday, sending
a cold front into the northern Big Country Saturday morning.
Previous GFS/ECMWF models runs indicated the front stalling south of
Interstate 20, across the northern Concho Valley or Heartland.
The 00z runs are less aggressive, keeping the front across the Big
Country. Although the farther south solution is still possible,
PoPs were reduced slightly across much of the region, especially
for areas south of Interstate 20. The best chance of showers and
thunderstorms looks to be across the northern Big Country. Rain
chances will linger into Sunday, mainly across the Big Country,
with the remnant front still in the area. Highs this weekend will
range from the mid and upper 80s across much of the Big Country,
to the upper 80s to lower 90s elsewhere.
Upper level ridging will build back across West Central Texas next
week. This will result in a return of above normal temperatures and
generally dry conditions.
Daniels
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 95 73 96 72 / 0 0 0 20
San Angelo 96 72 97 72 / 0 0 0 5
Junction 94 70 94 71 / 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
20/Daniels
Area Forecast Discussion
National Weather Service Spokane WA
254 AM PDT THU SEP 17 2015
.SYNOPSIS...
Today will be a cool and showery day with the best chance for
precipitation over the central and southern Idaho Panhandle. A
warming trend is expected Friday through the weekend with
temperatures climbing into the 70s Saturday and Sunday. A strong
frontal system will bring windy weather to the region on Sunday.
Next week looks dry Monday through Wednesday with near average
temperatures.
&&
.DISCUSSION...
Today through Friday night...An upper level trough off the
Washington coast will drop southeast across southern Washington,
Oregon, and central Idaho today. With this trajectory models
continue to favor rain showers along the East Slopes of the
Cascades, SE Washington, Lewiston area, Camas Prairie, and Central
Panhandle Mountains. Models continue to show some differences with
qpf totals, but have leaned more heavily towards the ECMWF
solutions which has the best handle on precip totals thus far. The
ECMWF suggests around a tenth of an inch or less in the
aforementioned areas...with only a chance of showers elsewhere.
Overall this is a decrease compared to what was previously
expected. For this afternoon models show the best instability over
the Idaho Panhandle and Camas Prairie where a slight chance of
thunderstorms is forecast over the high terrain. If any storms
occur they will be brief and short lived with cloud cover likely
be a limiting factor for storm development.
This system exits tonight bringing about drier conditions except
for possibly a few lingering showers over the Idaho Panhandle. A
moist boundary layer over NE Washington and North Idaho Panhandle
will likely lead to increasing areas of stratus and patchy fog
overnight into Friday morning. Another system passes by north of
the Canadian border Friday afternoon into Friday night. Main
impact from this will be mid and high clouds...along with a chance
of light showers or sprinkles near the Canadian border and Cascade
crest. JW
Saturday and Sunday: The evening model runs continue to forecast a
mainly dry weekend with the passage of a vigorous low pressure
system through southern Canada on Sunday. What this system lacks
in precipitation, it will compensate with wind. The brunt of the
wind will occur on Sunday as a deep surface low forms in the lee
of the Canadian Rockies north of Calgary. The tight westerly
pressure gradient will peak late in the day Sunday between the
Alberta low and high pressure along the Washington coast. Strong
momentum aloft will contribute to the windy conditions as a 120kt
jet core (at 250mb) sets up the BC/Washington border. With 850mb
winds of in the neighborhood of 30kts over central Washington to
the Idaho Panhandle, it looks like sustained winds of 20-25mph in
the afternoon with gusts to 35 mph. Blowing dust may need to be
added to the forecast especially if rain does not materialize
today. As far as precipitation chances, the Cascade crest will
have the best shot of rain (60-80 percent) with the cold frontal
passage Sunday afternoon/ evening. Chances east of the Cascades
will fall off dramatically in the strong west flow with 20-40
percent chances in the mountains along the Canadian border, and 10
percent or less in the Basin, Palouse, Spokane area.
Monday through Wednesday: Behind Sunday`s cold front, Monday looks
to be breezy in the afternoon with afternoon winds in the 10-20mph
range. Humidity levels on Monday will be considerably lower than
on Sunday, and we may see some areas flirt with Red Flag criteria
for wind and low humidity. As the winds diminish Monday night, the
dry air mass over the region combined with clearing skies will
support strong radiational cooling. Sheltered valleys in north
Idaho and northeast Washington will drop into the lower to mid
30s Tuesday and Wednesday morning. Look for large diurnal
temperature swings with places like Deer Park, Springdale, and
Republic. Morning lows in the low 30s Tuesday/Wednesday morning
climbing to near 70 in the afternoon. We are nearing the autumn
equinox, a time for big diurnal temperature swings. /GKoch
&&
.AVIATION...
06Z TAFS: Light rain expected to develop over Central and
Southeast Washington into the lower Idaho Panhandle by 10Z...spreading
to all TAF sites after 15Z. The system is splitting while coming
onshore and looks to bring very light spotty rain in the northern
Basin and northern mountains. CIGS are expected to remain
VFR at the TAF sites through 12z Thursday but there is a chance
of MVFR Ceilings after 15Z near the Cascades and over SE Washington.
Rain will transition to showers after 18z with a small chance for a
few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z.
Confidence for t-storms is low at this point. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 46 64 47 72 53 / 50 10 10 10 10 10
Coeur d`Alene 58 46 64 46 71 50 / 60 20 10 10 10 10
Pullman 58 45 67 46 72 50 / 70 10 10 0 10 10
Lewiston 63 49 73 50 77 55 / 70 10 10 0 10 0
Colville 59 45 64 45 73 48 / 30 10 10 10 10 10
Sandpoint 58 44 62 43 68 46 / 40 20 20 10 10 10
Kellogg 56 46 63 44 67 48 / 70 50 20 10 10 10
Moses Lake 67 45 72 48 77 53 / 40 10 0 0 10 10
Wenatchee 68 51 71 54 79 59 / 50 10 0 0 10 10
Omak 67 44 71 49 76 52 / 40 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
254 AM PDT THU SEP 17 2015
.SYNOPSIS...
Today will be a cool and showery day with the best chance for
precipitation over the central and southern Idaho Panhandle. A
warming trend is expected Friday through the weekend with
temperatures climbing into the 70s Saturday and Sunday. A strong
frontal system will bring windy weather to the region on Sunday.
Next week looks dry Monday through Wednesday with near average
temperatures.
&&
.DISCUSSION...
Today through Friday night...An upper level trough off the
Washington coast will drop southeast across southern Washington,
Oregon, and central Idaho today. With this trajectory models
continue to favor rain showers along the East Slopes of the
Cascades, SE Washington, Lewiston area, Camas Prairie, and Central
Panhandle Mountains. Models continue to show some differences with
qpf totals, but have leaned more heavily towards the ECMWF
solutions which has the best handle on precip totals thus far. The
ECMWF suggests around a tenth of an inch or less in the
aforementioned areas...with only a chance of showers elsewhere.
Overall this is a decrease compared to what was previously
expected. For this afternoon models show the best instability over
the Idaho Panhandle and Camas Prairie where a slight chance of
thunderstorms is forecast over the high terrain. If any storms
occur they will be brief and short lived with cloud cover likely
be a limiting factor for storm development.
This system exits tonight bringing about drier conditions except
for possibly a few lingering showers over the Idaho Panhandle. A
moist boundary layer over NE Washington and North Idaho Panhandle
will likely lead to increasing areas of stratus and patchy fog
overnight into Friday morning. Another system passes by north of
the Canadian border Friday afternoon into Friday night. Main
impact from this will be mid and high clouds...along with a chance
of light showers or sprinkles near the Canadian border and Cascade
crest. JW
Saturday and Sunday: The evening model runs continue to forecast a
mainly dry weekend with the passage of a vigorous low pressure
system through southern Canada on Sunday. What this system lacks
in precipitation, it will compensate with wind. The brunt of the
wind will occur on Sunday as a deep surface low forms in the lee
of the Canadian Rockies north of Calgary. The tight westerly
pressure gradient will peak late in the day Sunday between the
Alberta low and high pressure along the Washington coast. Strong
momentum aloft will contribute to the windy conditions as a 120kt
jet core (at 250mb) sets up the BC/Washington border. With 850mb
winds of in the neighborhood of 30kts over central Washington to
the Idaho Panhandle, it looks like sustained winds of 20-25mph in
the afternoon with gusts to 35 mph. Blowing dust may need to be
added to the forecast especially if rain does not materialize
today. As far as precipitation chances, the Cascade crest will
have the best shot of rain (60-80 percent) with the cold frontal
passage Sunday afternoon/ evening. Chances east of the Cascades
will fall off dramatically in the strong west flow with 20-40
percent chances in the mountains along the Canadian border, and 10
percent or less in the Basin, Palouse, Spokane area.
Monday through Wednesday: Behind Sunday`s cold front, Monday looks
to be breezy in the afternoon with afternoon winds in the 10-20mph
range. Humidity levels on Monday will be considerably lower than
on Sunday, and we may see some areas flirt with Red Flag criteria
for wind and low humidity. As the winds diminish Monday night, the
dry air mass over the region combined with clearing skies will
support strong radiational cooling. Sheltered valleys in north
Idaho and northeast Washington will drop into the lower to mid
30s Tuesday and Wednesday morning. Look for large diurnal
temperature swings with places like Deer Park, Springdale, and
Republic. Morning lows in the low 30s Tuesday/Wednesday morning
climbing to near 70 in the afternoon. We are nearing the autumn
equinox, a time for big diurnal temperature swings. /GKoch
&&
.AVIATION...
06Z TAFS: Light rain expected to develop over Central and
Southeast Washington into the lower Idaho Panhandle by 10Z...spreading
to all TAF sites after 15Z. The system is splitting while coming
onshore and looks to bring very light spotty rain in the northern
Basin and northern mountains. CIGS are expected to remain
VFR at the TAF sites through 12z Thursday but there is a chance
of MVFR Ceilings after 15Z near the Cascades and over SE Washington.
Rain will transition to showers after 18z with a small chance for a
few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z.
Confidence for t-storms is low at this point. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 46 64 47 72 53 / 50 10 10 10 10 10
Coeur d`Alene 58 46 64 46 71 50 / 60 20 10 10 10 10
Pullman 58 45 67 46 72 50 / 70 10 10 0 10 10
Lewiston 63 49 73 50 77 55 / 70 10 10 0 10 0
Colville 59 45 64 45 73 48 / 30 10 10 10 10 10
Sandpoint 58 44 62 43 68 46 / 40 20 20 10 10 10
Kellogg 56 46 63 44 67 48 / 70 50 20 10 10 10
Moses Lake 67 45 72 48 77 53 / 40 10 0 0 10 10
Wenatchee 68 51 71 54 79 59 / 50 10 0 0 10 10
Omak 67 44 71 49 76 52 / 40 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1147 PM PDT WED SEP 16 2015
.SYNOPSIS...
Cool and showery conditions will prevail through the week as a
series of Pacific storms move through the Inland Northwest.
Tonight into Thursday will feature our best shot of rain. Look
for a warming and drying trend over the weekend. Breezy conditions
are expected Sunday and Monday followed by mild and dry conditions
early next week.
&&
.DISCUSSION...
Late evening update just sent out based on current radar trends
and model data. Main changes were to further lower pops tonight
based on latest HRRR data which shows the best chances for rain
along the East Slopes of the Cascades, and over SE Washington and
the Camas Prairie late tonight. Satellite shows a couple waves
with one tracking towards western Washington and another over
Oregon that will track towards Central Idaho tonight. The 00z
ECMWF appears to have the best handle on this scenario with the
GFS and NAM overdone with its current precipitation totals over
western and south central Washington. JW
&&
.AVIATION...
06Z TAFS: Light rain expected to develop over Central and
Southeast Washington into the lower Idaho Panhandle by 10Z...spreading
to all TAF sites after 15Z. The system is splitting while coming
onshore and looks to bring very light spotty rain in the northern
Basin and northern mountains. CIGS are expected to remain
VFR at the TAF sites through 12z Thursday but there is a chance
of MVFR Ceilings after 15Z near the Cascades and over SE Washington.
Rain will transition to showers after 18z with a small chance for a
few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z.
Confidence for t-storms is low at this point. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 46 56 46 64 46 71 / 10 70 20 10 10 10
Coeur d`Alene 45 57 49 63 43 70 / 10 70 30 10 10 10
Pullman 45 56 45 65 44 72 / 40 70 20 10 0 10
Lewiston 51 63 49 71 50 77 / 50 80 20 10 0 10
Colville 42 58 45 65 41 71 / 10 60 20 10 10 10
Sandpoint 37 56 44 60 39 67 / 0 70 30 20 10 10
Kellogg 42 54 46 61 42 66 / 10 70 50 10 10 10
Moses Lake 48 65 45 71 47 77 / 20 40 10 0 0 10
Wenatchee 53 66 51 72 53 78 / 20 50 10 0 10 10
Omak 49 66 46 70 48 77 / 10 40 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND FRIDAY
ISSUED AT 310 AM CDT THU SEP 17 2015
FORECAST CHALLENGE CENTERS ON CONVECTION TRENDS TODAY INTO
TONIGHT AND SEVERE POTENTIAL.
AREA RADARS SHOW LEAD CONVECTION EARLY THIS MORNING NEAR THE
MINNESOTA WISCONSIN BORDER IN THE LLJ REGION...HIGHER PWATS AND
850 MB WARM AIR ADVECTION. THIS FOCUS OF CONVECTION WILL
GRADUALLY SHIFT EASTWARD TODAY BUT MAY DIMINISH FOR A PERIOD LATER
THIS MORNING. A COLD FRONT AND MID LEVEL TROUGH WITH EVEN MORE
CONVECTION WAS OVER THE NORTHERN PLAINS AND APPROACHING THE
WESTERN GREAT LAKES REGION TODAY. SHOWERS AND STORMS WILL LIKELY
BECOME MORE WIDESPREAD BY THIS AFTERNOON OVER WESTERN WISCONSIN
AND THEN TOWARD EASTERN AREAS BY THIS EVENING AS THE INITIAL
CONVECTION MERGES WITH THE WITH THE APPROACHING NORTHERN PLAINS
SYSTEM. HRRR MODEL KEEPS THE LEAD WARM SECTOR CONVECTION AND THE
FRONTAL CONVECTION A BIT MORE SEPARATE. BLEND OF MODEL RUNS
SUGGEST A FASTER DEPARTURE TOWARD FRIDAY MORNING...WITH PERHAPS A
BREAK IN PCPN FOR MUCH OF FRIDAY. PCPN BEGINS TO SPREAD BACK INTO
THE AREA FROM SOUTHWEST TO NORTHEAST AS A SURFACE WAVE TRACKS
ALONG THE FRONTAL BOUNDARY SOUTH OF THE AREA. THE NORTHERN AREAS
ARE EXPECTED TO BE OVERALL DRY ON FRIDAY. LIFT WITH THE RRQ
REGION OF THE UPPER JET NOT EXPECTED TO AFFECT THE AREA UNTIL
AFTER FRIDAY AFTERNOON.
AS FAR AS SEVERE POTENTIAL. BEST ML CAPE VALUES OCCUR THIS
AFTERNOON OVER THE WEST HALF OF THE STATE INCLUDING CENTRAL AND
NORTH CENTRAL WISCONSIN AND TOWARD EARLY EVENING OVER EASTERN
AREAS. SHEAR WILL BE ON THE INCREASE THIS AFTERNOON AND EARLY
EVENING AS MID LEVEL WINDS INCREASE AND TURN MORE WSW AS A MID
LEVEL TROUGH OF LOW PRESSURE SLIDES ALONG THE US/CANADA BORDER.
THESE LIKELY STRONGER WINDS ALOFT WILL INTERACT WITH THE SOUTH
FLOW IN THE BOUNDARY LAYER AHEAD OF THE FRONT. THIS INCREASE IN
SHEAR AND INSTABILITY WILL PRODUCE A WINDOW OF SEVERE
POTENTIAL...BUT THE STRONGER WINDS ALOFT MAY ALSO PUSH THE STORMS
EASTWARD FASTER OVERNIGHT. THE PRIMARY ISSUE WILL BE HEAVY RAIN
DUE TO HIGHER PWATS AND DAMAGING WINDS. HAIL POSSIBLE WITH ANY
SUPER STORM DEVELOPMENT IN THE SHEARED ENVIRONMENT BUT PROGGED
FORECAST SOUNDINGS INDICATE WBZ START TO FALL BELOW 10000 FEET
WELL AFTER THE FROPA AND CONVECTION. AMOUNT OF CLOUDS TODAY WILL
OBVIOUSLY AFFECT AVAILABLE INSTABILITY. SPC HAS PAINTED A SLIGHT
RISK DAY 1 TODAY OVER ALL OF CENTRAL WISCONSIN AND PARTS OF NORTH
CENTRAL AND NORTHEAST WISCONSIN.
LAST DAY OF ABOVE NORMAL TEMPERATURES THIS WEEK FOR TODAY
FOLLOWED WITH NEAR NORMAL TEMPERATURES ON FRIDAY IN THE WAKE OF
THE COLD FRONT.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 310 AM CDT THU SEP 17 2015
A WET START TO THE EXTENDED FCST AS A STRENGTHENING SFC LOW RIDES
NE THRU THE GREAT LAKES...TRAILED BY A STRONG SHORTWAVE TROF. ONCE
THIS SYSTEM CLEARS...MEAN FLOW TO BE DOMINATED BY A STRONG BAND OF
WESTERLIES RUNNING FROM THE PAC NW E-EN INTO S-CNTRL CANADA. THIS
KEEPS MOST WEATHER SYSTEMS TO OUR NW FOR THE FIRST HALF OF NEXT
WEEK WITH TEMPS HOVERING NEAR OR SLIGHTLY ABOVE NORMAL.
MODELS CONT TO BATTLE WITH THE INTERACTION OF A STRENGTHENING AREA
OF LOW PRES RIDING NE ALONG THE CDFNT AND THE APPROACH OF A STRONG
SHORTWAVE TROF/EMBEDDED SHORTWAVES FRI NGT. THE NAM REMAINS
STRONGEST/FARTHEST WEST WITH THE TRACK OF THE SFC LOW...ALTHO THE
ECMWF HAS TRENDED CLOSER TO THE NAM SOLUTION THAN 24 HOURS AGO.
THE GFS/GEM ARE WEAKER/BIT FARTHER EAST WITH THE LOW TRACK. MODELS
DO AGREE ON TWO MAIN AREAS OF PCPN WITH ONE STAYING TO OUR SOUTH
ASSOCIATED WITH STRONG ISEN LIFT AND THE OTHER MOVING THRU WI
ASSOCIATED WITH THE PRIMARY DEFORMATION ZONE. DESPITE THE MODEL
DIFFERENCES...IT APPEARS THAT THE SE HALF OF WI COULD RECEIVE A
HEALTHY RAINFALL FRI NGT WITH LOCALLY HEAVY RAINS POSSIBLE. MIN
TEMPS TO RANGE FROM THE 45-50 DEG RANGE NORTH...LWR TO MID 50S
SOUTH.
THE BIGGER FCST ISSUE MAY ACTUALLY BE WHEN TO END THE PCPN CHCS ON
SAT AS THE SLOWER NAM WOULD KEEP SHWRS GOING ALL DAY AS OPPOSED TO
THE SHWRS ENDING BY MIDDAY ON THE OTHER MODELS. HAVE CONTINUED TO
LEAN TOWARD THE MAJORITY SOLUTION MAINLY DUE TO THE PROGRESSIVE
NATURE OF THE MEAN FLOW. THEREFORE...WL KEEP POPS IN THE FCST THRU
SAT MORNING AND TREND TOWARD DECREASING CLOUDS IN THE AFTERNOON.
MAX TEMPS ARE EXPECTED TO DIP SLIGHTLY BELOW NORMAL WITH READINGS
GENERALLY IN THE LWR TO MID 60S NORTH...MID TO UPR 60S SOUTH.
HI PRES IS FCST TO MOVE EAST FROM THE CNTRL PLAINS TOWARD SRN
SECTIONS OF THE GREAT LAKES SAT NGT. MOSTLY CLEAR TO PARTLY CLOUDY
SKIES...LIGHT WINDS AND A DRIER AIR MASS WL ALLOW FOR TEMPS TO
FALL TO AROUND 40 DEGS OVER THE COLDER LOCATIONS OF THE
NORTHWOODS...AROUND 50 DEGS ALONG LAKE MI. DEPENDING ON HOW MUCH
RAIN FALLS FRI NGT/SAT MORNING...THERE COULD BE PATCHY FOG
DEVELOPING JUST ABOUT ANYWHERE OVER NE WI. THE SFC HI WL DRIFT
ACROSS THE GREAT LAKES ON SUNDAY WITH A RETURN FLOW DEVELOPING
OVER WI. IN ADDITION...MODELS SUGGEST A WEAK SHORTWAVE TROF WL
APPROACH THE GREAT LAKES SUNDAY AFTERNOON. THERE IS NOT ENUF LIFT/
FORCING/MOISTURE FOR ANY PCPN TO DEVELOP...HOWEVER WE MAY SEE SOME
CLOUDS PUSH INTO THE FCST AREA THROUGHOUT THE DAY. MAX TEMPS
SHOULD BE CLOSE TO SEASONAL NORMALS WITH PLENTY OF UPR 60S TO LWR
70S.
THIS WEAK SHORTWAVE TROF PUSHES ACROSS WI WITH ITS PASSING CLOUDS
SUNDAY NGT...THEN THE MODELS BRING RISING UPR HEIGHTS INTO THE
REGION ON MON AS SOUTHERLY WINDS TO PREVAIL. MORE SUNSHINE ON MON
WL HELP NUDGE TEMPS UP A TAD WITH READINGS RANGING FROM AROUND 70
DEGS TO THE LWR 70S. QUIET WEATHER CONDITIONS TO PREVAIL THRU TUE
WITH UPR RIDGING OVER THE WRN GREAT LAKES. MODELS DO SHOW A MODEST
CDFNT PUSHING ACROSS THE UPR MS VALLEY ON TUE...BUT BE TOO FAR
AWAY YET TO IMPACT OUR WEATHER. LOOK FOR MAX TEMPS TUE TO RANGE
FROM THE UPR 60S NEAR LAKE MI...TO THE LWR TO MID 70S OVER PARTS
OF CNTRL WI.
THE MOVEMENT OF THIS CDFNT WL ULTIMATELY DETERMINE WHEN TO PLACE
THE NEXT CHC FOR SHWRS/TSTMS INTO THE FCST. FULLY ANTICIPATE THE
MODELS TO WAFFLE ON NOT ONLY THE LOCATION OF THE FNT...BUT ALSO
HOW MUCH MOISTURE WL BE AVAILABLE WHEN THE FNT DOES ARRIVE. HAVE
FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH ONLY BRINGS A
MINIMAL POP TO N-CNTRL WI TUE NGT AND WED.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1054 PM CDT WED SEP 16 2015
SHOULD BE MAINLY VFR TONIGHT THOUGH SOME SHOWERS ARE
NOT OUT OF THE QUESTION OVER THE NORTH. LOW LEVEL WIND SHEAR IS
LIKELY WITH SOUTHWEST WINDS AROUND 35 KNOTS AT 1000` AGL AND
LIGHT SOUTH SURFACE WINDS. THURSDAY WILL BE CLOUDY WITH SHOWERS
AND THUNDERSTORMS ARRIVING FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON. SOME STRONG OR SEVERE STORMS ARE POSSIBLE IN THE
AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS TUCSON AZ
859 AM MST THU SEP 17 2015
.SYNOPSIS...EXPECT MAINLY DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH FRIDAY ALTHOUGH AND ISOLATED THUNDERSTORM WILL BE POSSIBLE
OVER COCHISE COUNTY. A CHANCE OF SHOWERS AND THUNDERSTORMS GENERALLY
EAST OF TUCSON WILL RETURN THIS WEEKEND...THEN MORE WIDESPREAD
MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.
TEMPERATURES WILL BE NEAR SEASONAL NORMALS THROUGH THIS
WEEKEND...THEN LOWERING TO BELOW NORMAL VALUES BY TUESDAY.
&&
.DISCUSSION...A GORGEOUS MORNING ACROSS SOUTHEAST ARIZONA WITH JUST
A FEW MID-LEVEL CLOUDS FROM TUCSON AND POINTS EAST. TEMPERATURES
WERE JUST ABOUT UNCHANGED FROM THIS TIME YESTERDAY...WHILE DEWPOINTS
WERE 2 TO 8 DEGS F DRIER. THE 12Z KTWC SOUNDING CONTINUES TO SHOW AN
UNSUPPORTIVE ATMOSPHERE FOR CONVECTION TODAY EVEN THOUGH THE PWAT
VALUE OF 1.20 INCH IS STILL ABOVE NORMAL. THE MEAGER MOISTURE
PRESENT IS ALL CONFINED BELOW 700 MB WITH YET ANOTHER RECORD WARM
TEMPERATURE OF -2.5 DEGS C AT 500 MB PER THE SPC SOUNDING
CLIMATOLOGY PAGE. THAT SAID...FORECAST SOUNDINGS ACROSS PARTS OF
COCHISE COUNTY SHOW JUST ENOUGH LOW-LEVEL MOISTURE TO SUPPORT
PERHAPS A SHOWER OR TWO LATE THIS AFTERNOON. THIS NOTION IS BACKED
UP BY THE RECENT 17/14Z HRRR AND THE 17/12Z UNIV. OF AZ WRF-NAM.
WE`RE CARRYING LOW-END SLIGHT CHANCE POPS THERE SO NO UPDATES WILL
BE NECESSARY THIS MORNING.
MORE ON THE POTENTIAL RETURN OF MOISTURE AND PRECIPITATION CHANCES
THIS WEEKEND AND EARLY NEXT WEEK IN THE AFTEROON PACKAGE.
&&
.AVIATION...VALID THRU 18/18Z.
FEW CLOUDS AT 10-14 KFT AGL WITH FEW-SCT CUMULUS RE-DEVELOPING AT 6-
9 KFT AGL THROUGH THIS MORNING. AN ISOLATED -SHRA/-TSRA MAY OCCUR
THIS AFTERNOON OVER COCHISE COUNTY. WINDS WILL GENERALLY BE LIGHT
AND TERRAIN DRIVEN THIS MORNING...THEN BECOME SW AT 10-15 KTS WITH A
FEW GUSTS TO 25 MPH THIS AFTERNOON. ANY GUSTINESS WILL SUBSIDE
QUICKLY AFTER 18/01Z WITH SURFACE WINDS BECOMING LIGHT AND TERRAIN
DRIVEN OVERNIGHT. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED THROUGH FRIDAY
ALTHOUGH AN ISOLATED SHOWER/THUNDERSTORM CANNOT BE RULED OUT SOUTH
AND EAST OF TUCSON. A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY
EAST OF TUCSON WILL RETURN THIS WEEKEND...THEN MORE WIDESPREAD
MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.
SOUTHWEST WINDS...OCCASIONALLY GUSTY DURING THE AFTERNOON WILL
PREVAIL THE NEXT SEVERAL DAYS. OTHERWISE...20-FOOT WINDS WILL
GENERALLY BE LESS THAN 15 MPH.
&&
.PREV DISCUSSION...A DRY WESTERLY FLOW WILL CONTINUE TO PROVIDE THE
AREA WITH SEASONABLE DAYTIME TEMPERATURES THROUGH FRIDAY.
THEREAFTER...MODELS SUGGEST THE FLOW PATTERN WILL CHANGE THIS
WEEKEND AS THE WESTERLY FLOW BEGINS TO BECOME MORE SOUTHERLY. THIS
WILL RESULT IN AN INCREASE IN MOISTURE...ESPECIALLY FROM TUCSON
EASTWARD. AS A RESULT...THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS OVER THE WEEKEND...MAINLY EAST OF TUCSON. A MORE
SIGNIFICANT CHANGE WAS PROGGED EARLY NEXT WEEK AS DEEPER MOISTURE
SPREADS NORTHWARD THROUGH BAJA AND INTO THE DESERT SOUTHWEST. THIS
INCREASE IN MOISTURE WAS ASSOCIATED WITH A LOW PRESSURE SYSTEM
APPROACHING THE SOUTHERN CALIFORNIA COAST. THE END RESULT WILL BE
INCREASING CHANCES OF RAIN MONDAY INTO EARLY WEDNESDAY WITH THE BEST
CHANCE ON TUESDAY AS THE LOW PRESSURE SYSTEM ENTERS ARIZONA.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
CARLAW
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
907 AM EDT THU SEP 17 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA WILL MOVE SLOWLY EASTWARD THROUGH
SATURDAY. A WEAK COLD FRONT WILL THEN CROSS THE REGION SATURDAY
NIGHT INTO SUNDAY MORNING. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND ON SUNDAY AND MONDAY, WITH LOW PRESSURE DEVELOPING NEAR
THE CAROLINA COAST ON TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MORNING 12Z SOUNDINGS MAXT SUGGESTIONS ARE 80-85 (SANS ELEVATION
AND SEA BREEZE EFFECTS) FOR THIS AFTERNOON. SO NO BIG CHANGES TO
PREDICTED HIGH TEMPS. LAST COUPLE OF HRRR RUNS ARE SLIGHTLY
STRONGER WITH THE SEA BREEZE CIRCULATION. WE BLENDED THEM AND
CONTINUITY.
A 1024 MB SURFACE HIGH WAS STILL OVER THE MID-ATLANTIC REGION
THIS MORNING. IR SATELLITE SHOWS SOME HIGH CLOUDS STREAMING OVER
SRN NJ/DE IN ASSOCIATED WITH AN UPPER-LEVEL JET STREAK TO OUR
SOUTH. THIS IS SLOWLY EASING OFFSHORE.
THE CENTER OF THE SURFACE HIGH IS FORECAST TO PROGRESS OFFSHORE THIS
AFTERNOON, BUT OUR REGION WILL STILL BE UNDER THE INFLUENCE OF HIGH
PRESSURE. ENSUING SOUTHERLY RETURN FLOW ON THE WESTERN PERIPHERY OF
THE RIDGE WILL BE VERY LIGHT BUT ACTUALLY PRODUCE A MODEST CAA
PATTERN AS 1) THE CORE OF THE WARMER AIR PROGRESS FARTHER DOWNSTREAM
OFF THE NEW ENGLAND COAST AND 2) COOLER AIR ASSOCIATED WITH AN UPPER
SHORTWAVE TROUGH MOVES OVERHEAD. ACCORDINGLY, EXPECT A REPEAT OF
YESTERDAY WX WISE THOUGH MAX TEMPS MAY BE 1-2F COOLER THIS AFTERNOON
THAN YESTERDAY. SUNNY SKIES AND LIGHT WINDS CAN ALSO BE EXPECTED.
THE AIRMASS WILL REMAIN DRY WITH DEWPOINTS DROPPING INTO THE LOWER
50S INLAND BY THE AFTERNOON. DEWPOINTS IN THE 60S ARE FAVORED CLOSER
TO THE COAST WITH A SEA-BREEZE FRONT MOVING INLAND THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE HIGH WILL MOVE FARTHER OFFSHORE TONIGHT BUT THE NORTHEAST AND
MID-ATLANTIC STATES REMAIN ON THE WESTERN PERIPHERY OF THE HIGH. THE
GRADIENT OVER OUR AREA LOOKS TO BE WEAK ENOUGH FOR WINDS TO GO CALM
AS THE BOUNDARY LAYER DECOUPLES. WENT A FEW DEGREES BELOW STAT
GUIDANCE FOR MIN TEMPS (LOW TO MID 50S) IN THE RURAL VALLEYS AND
PINE BARRENS...THE AREAS THAT TYPICALLY RADIATE EFFECTIVELY.
RADIATIONAL FOG IS ONCE AGAIN EXPECTED IN THESE AREAS. FOR THE URBAN
AND COASTAL AREAS, FORECAST LOWS ARE IN THE 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HIGH PRES OVER THE REGION WILL BEGIN TO MOVE OFFSHORE ON FRI.
HOWEVER, ANOTHER NICE DAY IS EXPECTED WITH DRY AND WARM, BUT
PLEASANT CONDS.
MEANWHILE A LARGE LOW PRES SYS NEAR JAMES BAY WILL PUS EWD, WITH
ITS ATTENDANT CDFNT EXTENDING SWWD ACRS THE CNTRL PLAINS.
SECONDARY LOW PRES IS EXPECTED TO DEVELOP ALG THIS CDFNT, AND MOVE
NEWD TO SOMEWHERE NR THE GRTLKS BY SAT MRNG. HOWEVER, WE WILL
STILL BE INFLUENCED BY THE HIGH PRES TO THE E.
THE AFOREMENTIONED CDFNT WILL CONTINUE TO MOVE EWD, WITH THE LOW
PRES MOVG INTO SERN CAN. BY THE TIME IT REACHES OUR AREA SAT NIGHT
INTO ERLY SUN, THERE WILL HARDLY BE ANY MOISTURE WITH IT AT ALL.
IT IS PSBL THE FRONT COMES THRU COMPLETELY DRY, THOUGH ITS ALSO
PSBL THERE ARE AT LEAST A FEW SHWRS, MAINLY TO THE N. SO HAVE LEFT
SOME LOW POPS IN THESE AREAS.
BEHIND THE FRONT, HIGH PRES BUILDS TO OUR N FOR LATER SUN INTO MON
AND SOME SEMBLANCE OF LOW PRES WILL TAKE SHAPE OFF THE SERN CONUS
CST. ADDITIONALLY, AN H5 TROF BEGINS TO DEVELOP NR THE GRTLKS. SUN
LOOKS DRY ATTM. THE POSN OF THE HIGH WILL PUT US IN A NELY FLOW
AND BRING QUITE A BIT OF CLOUDS, BUT EXACTLY HOW THESE FEATURES
INTERACT AND WHERE ANY POTENTIAL LOW IS WILL DETERMINE IF AND
WHERE THERE IS RAIN ON MON. THE GFS HAS A WEAKER MORE ELY POSN LOW
AND KEEPS THE PRECIP MORE CONFINED TO COASTAL AREAS. THE ECMWF IS
STRONGER WITH THE LOW AND FURTHER W AND THE NELY FLOW BRINGS SOME
MOISTURE ONSHORE.
THE MDLS HAVE BEEN ANYTHING BUT CONSISTENT THE LAST FEW DAYS WRT
PRECIP ERLY NEXT WEEK, SO WHILE MON STILL LOOKS TO BE POTENTIALLY
THE BEST SHOT, STILL NOT HANGING MY HAT ON IT JUST YET UNTIL SEE
BETTER RUN-TO-RUN CONSISTENCY.
THE H5 TROF SHARPENS THRU THE COURSE OF THE WEEK AND AS IT MOVES
SWD SEEMS TO MOVE THE HIGH SWD AS WELL. THIS, IN TURN WANTS TO
SHUNT ANY PRECIP FURTHER AWAY FROM THE REGION. WHILE IT IS STILL
VERY CLOSE ON SOME DAYS, THE DIFFERENCE BETWEEN A NO POP AND VERY
LOW POP IS NOT MUCH AT THIS TIME SCALE SO HAVE KEPT MUCH OF THE
EXTENDD DRY.
HOWEVER, IT MUST BE NOTED THAT CONFIDENCE REMAINS LOWER THAN
AVERAGE ATTM.
TEMPS WILL START OFF ABV NRML, BUT THEN END UP AT OR SLIGHTLY
BELOW NRML.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR TODAY AND THIS EVENING. A LIGHT SOUTHERLY WINDS UNDER 10 KT
WILL DEVELOP TODAY.
WITH THE SAME AIRMASS IN PLACE, EXPECT RADIATIONAL FOG TO REDEVELOP
AT THE MORE RURAL AIRPORTS LATE TONIGHT.
OUTLOOK...
SAT...VFR CONDS EXPECTED AFTER PSBL LOWER CEILINGS/VSBYS IN
PATCHY FOG IN THE MRNG. MDT TO HIGH CONFIDENCE
SAT NIGHT AND SUN...VFR. LOW CHC SHRA AND MVFR, MAINLY NW OF
I-95. MDT TO HIGH CONFIDENCE.
MON...VFR. LOW CHC SHRA AND MVFR. LOW CONFIDENCE.
&&
.MARINE...
NO HAZARDS EXPECTED ON THE WATERS TODAY AND TONIGHT. A LIGHT WLY
WIND AROUND 5 KT THIS MORNING WILL BECOME SLY AND INCREASE TO AROUND
10 KT THIS AFTN AS A SEA-BREEZE FRONT MOVES INLAND.
OUTLOOK...
SAT THRU MON...CONDS WILL START OFF QUIET ON SAT INTO ERLY SUN.
HOWEVER, A CDFNT WILL MOVE ACRS THE REGION FROM LATE SAT INTO
SUN, REACHING THE CSTL WATERS ON SUN. BEHIND THE CDFNT, HIGH PRES
WILL BUILD TO THE NE ALLOWING FOR A MORE NELY FLOW TO DEVELOP LATER
SUN INTO MON. THIS WILL CAUSE WIND TO INCREASE AND SEAS TO BUILD.
PSBLY BY LATE SUN NIGHT, IF NOT ON MON, WILL LIKELY NEED A SCA.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...GIGI/KLEIN
SHORT TERM...KLEIN
LONG TERM...NIERENBERG
AVIATION...KLEIN/NIERENBERG
MARINE...KLEIN/NIERENBERG
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1058 AM EDT THU SEP 17 2015
.SYNOPSIS...
MOISTURE WILL OCCUR IN AN ONSHORE FLOW BUT THE DEEPER MOISTURE
WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. EXPECT WIDELY
SCATTERED SHOWERS IN THE CSRA AND SOUTHEAST MIDLANDS THROUGH
FRIDAY. IT WILL BE FAIR AND WARMER OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED
TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN
ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE
FORECAST AREA. THE HRRR DISPLAYS JUST ISOLATED SHOWERS IN THE
EAST PART THIS AFTERNOON. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING
MAY RESULT IN STRATUS LATE TONIGHT. THE GFS AND NAM MOS INDICATE
LOW CLOUDINESS DEVELOPING. THE TEMPERATURE GUIDANCE WAS
CONSISTENT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LITTLE CHANGE IN THE PATTERN TONIGHT INTO FRIDAY. LIMITED MOISTURE
IN THE MIDLANDS BUT WEAK ONSHORE FLOW CONTINUES WITH WEAK LOW
PRESSURE OFF THE COAST. WIDELY SCATTERED MAINLY AFTERNOON SHOWERS
IN THE EAST MIDLANDS. WITH AIR MASS MODIFICATION...WARMING
SLIGHTLY INTO FRIDAY. TEMPERATURES WILL BE CLOSE TO NORMAL.
SURFACE AND UPPER TROUGH MOVES EAST BY SATURDAY WITH WEAK UPPER
RIDGE BUILDING EAST FROM THE SOUTHERN PLAINS/GULF COAST. EXPECT
WARMING TREND AND LIMITED LOW LEVEL MOISTURE ACROSS AREA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
INCREASED POPS SLIGHTLY FROM PREVIOUS FORECAST BASED ON LATEST
00Z GFS AND WPC GUIDANCE...
HIGH PRESSURE WILL REMAIN THE DOMINATE FEATURE THROUGH THE
WEEKEND. A WEAK COLD FRONT AND ASSOCIATED SHORT WAVE WILL APPROACH
THE AREA MONDAY INCREASING THE THREAT OF CONVECTION LATE MONDAY
INTO TUESDAY. ONCE AGAIN...LOOKS LIKE THE MID/UPPER LEVEL SYSTEM
WILL CLOSE OFF ACROSS THE EAST BY MID WEEK. THIS WILL KEEP A
CHANCE OF SHOWERS IN THE FORECAST THROUGH THE MIDDLE OF NEXT WEEK.
TEMPS WILL MODERATE HEADING INTO THE WEEKEND WITH HIGHS IN THE
UPPER 80S TO POSSIBLY LOWER 90S IN A FEW AREAS OVER THE WEEKEND
BEFORE COOLING DOWN SLIGHTLY NEXT WEEK. EXPECT OVERNIGHT LOWS TO
BE SEASONAL IN THE LOWER/MIDDLE 60S.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.
HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED
TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN
ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE
TERMINALS. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN
RESTRICTIONS DURING THE EARLY MORNING HOURS FRIDAY. THE NAM AND
GFS MOS INDICATE MVFR OR IFR CONDITIONS DEVELOPING.
EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS IN FOG AND STRATUS
POSSIBLE EACH MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
828 AM EDT THU SEP 17 2015
.SYNOPSIS...
MOISTURE WILL OCCUR IN AN ONSHORE FLOW BUT THE DEEPER MOISTURE
WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. EXPECT WIDELY
SCATTERED SHOWERS IN THE CSRA AND SOUTHEAST MIDLANDS THROUGH
FRIDAY. IT WILL BE FAIR AND WARMER OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED
TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN
ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE
FORECAST AREA. THE HRRR DISPLAYS JUST ISOLATED SHOWERS IN THE
EAST PART THIS AFTERNOON. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING
MAY RESULT IN STRATUS LATE TONIGHT. THE GFS AND NAM MOS INDICATE
LOW CLOUDINESS DEVELOPING. THE TEMPERATURE GUIDANCE WAS
CONSISTENT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LITTLE CHANGE IN THE PATTERN TONIGHT INTO FRIDAY. LIMITED MOISTURE
IN THE MIDLANDS BUT WEAK ONSHORE FLOW CONTINUES WITH WEAK LOW
PRESSURE OFF THE COAST. WIDELY SCATTERED MAINLY AFTERNOON SHOWERS
IN THE EAST MIDLANDS. WITH AIR MASS MODIFICATION...WARMING
SLIGHTLY INTO FRIDAY. TEMPERATURES WILL BE CLOSE TO NORMAL.
SURFACE AND UPPER TROUGH MOVES EAST BY SATURDAY WITH WEAK UPPER
RIDGE BUILDING EAST FROM THE SOUTHERN PLAINS/GULF COAST. EXPECT
WARMING TREND AND LIMITED LOW LEVEL MOISTURE ACROSS AREA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
INCREASED POPS SLIGHTLY FROM PREVIOUS FORECAST BASED ON LATEST
00Z GFS AND WPC GUIDANCE...
HIGH PRESSURE WILL REMAIN THE DOMINATE FEATURE THROUGH THE
WEEKEND. A WEAK COLD FRONT AND ASSOCIATED SHORT WAVE WILL APPROACH
THE AREA MONDAY INCREASING THE THREAT OF CONVECTION LATE MONDAY
INTO TUESDAY. ONCE AGAIN...LOOKS LIKE THE MID/UPPER LEVEL SYSTEM
WILL CLOSE OFF ACROSS THE EAST BY MID WEEK. THIS WILL KEEP A
CHANCE OF SHOWERS IN THE FORECAST THROUGH THE MIDDLE OF NEXT WEEK.
TEMPS WILL MODERATE HEADING INTO THE WEEKEND WITH HIGHS IN THE
UPPER 80S TO POSSIBLY LOWER 90S IN A FEW AREAS OVER THE WEEKEND
BEFORE COOLING DOWN SLIGHTLY NEXT WEEK. EXPECT OVERNIGHT LOWS TO
BE SEASONAL IN THE LOWER/MIDDLE 60S.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.
HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED
TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN
ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE
TERMINALS. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN
RESTRICTIONS DURING THE EARLY MORNING HOURS FRIDAY. THE NAM AND
GFS MOS INDICATE MVFR OR IFR CONDITIONS DEVELOPING.
EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS IN FOG AND STRATUS
POSSIBLE EACH MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT THU SEP 17 2015
.UPDATE...
ISSUED AT 1045 AM CDT THU SEP 17 2015
At 1035am broken clouds are covering parts of eastern IL late this
morning. HiRes/short range models continue to show some scattered
light pcpn in the east, but just over the next couple of hours.
Believe those models not handling pcpn fields well, as they do not
have the larger area of pcpn in central and eastern Iowa. So will
making some adjustments to pops and removing slight chances for
the area and then adding some chance pops late this afternoon in
the northwest to account for area in eastern IA possibly spreading
south into extreme northwestern parts of the cwa. Remainder of
forecast looks fine. Update will be out shortly.
&&
.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT THU SEP 17 2015
The approaching cold front from the Plains will cause increasing
southerly flow in the lower troposphere, raising moisture levels
across the forecast area. Warm air advection showers are already
nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP
models show spotty showers advancing across our counties west of I-
55 this morning. Most spots will just see sprinkles, but a few
locations could get measurable rain under convective updrafts.
Therefore, we advanced slight chance PoPs into the western counties
over several hours this morning, then diminished just after Noon. A
return of slight chances for Knox and Stark counties is expected
after 3 pm/20z as a shortwave/low pressure begin to move northeast
along the front into Iowa.
Depending on cloud cover, high temps should climb to at or above
yesterdays very warm readings in the mid to upper 80s in the west,
with mid 80s in the east. Held off on low 90s, due to periodic cloud
cover limiting full warming potential.
South winds will become gusty today ahead of the cold front, with
sustained speeds of 15-20 mph, and gusts into the mid to upper 20
mph range this afternoon.
.LONG TERM...(TONIGHT THROUGH Wednesday)
ISSUED AT 335 AM CDT THU SEP 17 2015
Beyond today, the remaining of the forecast has a lot of agreement
in the models overall. The precipitation chances increase tonight
as the front gets closer to the region. The front slows a bit
tomorrow as it runs into mostly parallel flow out of the southwest,
but starts to break down the ridge over the eastern half of the
country. There is the potential for a bit of a break on Friday...but
that will depend highly on mesoscale features and cloud cover during
the day...and keeping the forecast to chance pops a a result. The
second wave is expected to bring increasing pops tomorrow night with
the actual fropa and wind shift coming in the early morning hours
for Saturday. Northwesterly winds for Saturday and lower max temps
in the upper 60s in the northern portions of the state, Central
Illinois in the 70s. More widespread 70s expected for Sunday
afternoon to wrap up the weekend. So far, the mid level temps in
the models are not pointing to a deep chill behind the cold front.
Although a few degrees below normal briefly, a general warming trend
will have Central Illinois back to climatological norms by midweek.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING)
ISSUED AT 700 AM CDT THU SEP 17 2015
Predominantly VFR aviation weather conditions expected across the
central Illinois terminals today through 00z/7pm. Clouds will
increase for the western terminals of PIA, BMI and SPI as moisture
increases ahead of a slowly approaching cold front. A few
sprinkles will even be possible today for PIA, BMI and SPI based
on the several high resolution models, but little aviation impact
is expected. Chances of showers or thunderstorms will increase
during the evening. After midnight, storms will become likely
west of I-55, including PIA/BMI/SPI. IFR conditions will be
possible during any storms. Once again, southerly winds will
persist through the period, with winds gusting to around 25 kts
during the peak diurnal mixing times today, them remaining 10-12kt
tonight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS LINCOLN IL
702 AM CDT THU SEP 17 2015
.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT THU SEP 17 2015
The approaching cold front from the Plains will cause increasing
southerly flow in the lower troposphere, raising moisture levels
across the forecast area. Warm air advection showers are already
nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP
models show spotty showers advancing across our counties west of I-
55 this morning. Most spots will just see sprinkles, but a few
locations could get measurable rain under convective updrafts.
Therefore, we advanced slight chance PoPs into the western counties
over several hours this morning, then diminished just after Noon. A
return of slight chances for Knox and Stark counties is expected
after 3 pm/20z as a shortwave/low pressure begin to move northeast
along the front into Iowa.
Depending on cloud cover, high temps should climb to at or above
yesterdays very warm readings in the mid to upper 80s in the west,
with mid 80s in the east. Held off on low 90s, due to periodic cloud
cover limiting full warming potential.
South winds will become gusty today ahead of the cold front, with
sustained speeds of 15-20 mph, and gusts into the mid to upper 20
mph range this afternoon.
.LONG TERM...(TONIGHT THROUGH Wednesday)
ISSUED AT 335 AM CDT THU SEP 17 2015
Beyond today, the remaining of the forecast has a lot of agreement
in the models overall. The precipitation chances increase tonight
as the front gets closer to the region. The front slows a bit
tomorrow as it runs into mostly parallel flow out of the southwest,
but starts to break down the ridge over the eastern half of the
country. There is the potential for a bit of a break on Friday...but
that will depend highly on mesoscale features and cloud cover during
the day...and keeping the forecast to chance pops a a result. The
second wave is expected to bring increasing pops tomorrow night with
the actual fropa and wind shift coming in the early morning hours
for Saturday. Northwesterly winds for Saturday and lower max temps
in the upper 60s in the northern portions of the state, Central
Illinois in the 70s. More widespread 70s expected for Sunday
afternoon to wrap up the weekend. So far, the mid level temps in
the models are not pointing to a deep chill behind the cold front.
Although a few degrees below normal briefly, a general warming trend
will have Central Illinois back to climatological norms by midweek.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING)
ISSUED AT 700 AM CDT THU SEP 17 2015
Predominantly VFR aviation weather conditions expected across the
central Illinois terminals today through 00z/7pm. Clouds will
increase for the western terminals of PIA, BMI and SPI as moisture
increases ahead of a slowly approaching cold front. A few
sprinkles will even be possible today for PIA, BMI and SPI based
on the several high resolution models, but little aviation impact
is expected. Chances of showers or thunderstorms will increase
during the evening. After midnight, storms will become likely
west of I-55, including PIA/BMI/SPI. IFR conditions will be
possible during any storms. Once again, southerly winds will
persist through the period, with winds gusting to around 25 kts
during the peak diurnal mixing times today, them remaining 10-12kt
tonight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS TOPEKA KS
640 AM CDT THU SEP 17 2015
...Update to aviation forecast discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU SEP 17 2015
An upper level trough was deepening across the eastern Pacific and
the western CONUS at 08Z. A stronger shortwave trough was moving
onshore into Washington state while an upper level ridge continued
across the southern Plains into the western Gulf with southwesterly
upper flow across the Central Plains. A few embedded waves were
moving across the Northern Plains early this morning. Isentropic
lift in the 315K-320K layer was developing a few isolated showers in
north central and northeast Kansas. Short range hi resolution
models, including the experimental HRRR show isolated to scattered
elevated convection across the forecast area, but mainly focusing
across northeast Kansas by sunrise. A frontal boundary was located
from central South Dakota to a low pressure area in southwest
Nebraska then into eastern Colorado. A trough moving across the
Northern Plains today should push the front southeast into north
central Kansas later this afternoon then extend from Hiawatha to
Abilene by late evening. The front looks to stall out across the
forecast area after midnight from northwest Missouri into south
central Kansas. Expect the isolated showers and thunderstorms
through the morning hours before moving off to the northeast. Expect
a break for much of the afternoon as there is little in the way of
any lift and convergence along the front is expected to be weak and
forecast soundings show EML capping surface convection for the
afternoon. That said convective inhibition will begin to wane late
in the day and have maintained increasing pops along the frontal
zone. Tonight the low level jet will be orientated parallel to the
frontal boundary with the pooling of moisture near the front,
especially in northeast Kansas initially before shifting to the
southeast through the night. Isentropic lift and convergence are
also initially focused in the northeast and into northwest Missouri
then shifts southward through the night into east central Kansas.
Shear and instability will be sufficient for a few strong to severe
storms tonight. Locally heavy rainfall is also possible where storms
train along the boundary. Mixing to around 850 mb today will make
for highs in the upper 80s to mid 90s. Lows tonight will cool into
the 60s north of the front and lower 70s to its south.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 340 AM CDT THU SEP 17 2015
By Friday morning, the cold front should be stretched across the
southeastern portion of the CWA and lift a bit to the north through
the morning hours. This front finally will progress eastward through
the afternoon and evening hours as the secondary mid-level trough
sweeps into the Northern and Central Plains, thus helping to push
this system eastward out of the area. Models show that we may lose
some of the available lift during the morning hours on Friday, so
there may only be some scattered morning showers and thunderstorms.
However, thunderstorm potential looks to increase during the
afternoon hours and into the evening as the forcing/lift increases
across the area with the progressing front and support from the mid-
level trough approaching the area. Soundings show the cap
potentially eroding away by mid-afternoon, when the front should be
nearly bisecting the CWA from southwest to northeast. This available
lift/forcing combined with limited inhibition by mid-afternoon, CAPE
values increasing to upwards of around 2000 J/kg, and 0-6 km bulk
shear values increasing to at least 35-40kts, should result in the
potential for some severe thunderstorm development mid Friday
afternoon into Friday evening. While the primary hazards will be
damaging winds and large hail, 0-1 km shear and helicity values
suggest even the potential for a few isolated tornadoes as well.
While these afternoon storms should be a bit more progressive, with
PWAT values in the 1.7-1.9 inch range and the low/mid level jets
expected to be nearly parallel to the boundary, cannot rule out the
potential for some locally heavy rain that could potentially lead to
some localized flash flooding. The severe threat should diminish by
late evening with a dry forecast in place for the entire CWA by the
overnight hours (early Saturday morning).
Surface high pressure will surge into the central U.S. behind the
exiting system, ushering cooler air into the region. Have continued
to trend a bit cooler for high temperatures on Saturday as northerly
winds may only allow afternoon highs to reach into the low/mid 70s.
Lows Saturday night should drop into the low 50s. Winds will shift
around to the southeast by Sunday, pushing highs a few degrees
higher into the mid/upper 70s. Models continue to show an embedded
shortwave trough developing within the mid-level flow over the
central U.S. on Sunday, however the best moisture and lift look to
remain further south of the CWA so have kept a dry forecast for
Sunday.
A mid-level ridge will build back into the Southern and Central
Plains by early next week. With surface high pressure shifting east
of the area, southerly winds will help to gradually moderate high
temperatures into the low/mid 80s by Tuesday. Models start diverging
in their solutions by mid-week as the GFS develops an embedded wave
along the western ridge axis that could potentially result in some
precipitation skimming the CWA, while the ECMWF keeps the area dry.
While confidence is low in the precip potential, have only some low-
end slight chance PoPs in for Wednesday night into Thursday.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING)
ISSUED AT 640 AM CDT THU SEP 17 2015
Isolated showers and thunderstorms will affect the terminals this
morning, first at MHK then FOE and TOP after 14Z. Kept low level
wind shear at TOP and FOE through 14Z. Approach of a cold front
will have some scattered tsra after 23Z and continue through the
end of the period. For now have gone with VCTS. Winds shift to the
north at MHK after 03Z. Front likely to not move through TOP and
FOE attm so southerly winds should continue.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...53
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
644 AM CDT THU SEP 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT THU SEP 17 2015
A VERY SUMMER FEEL TO THE WEATHER THIS MORNING...WITH 3 AM
TEMPERATURES ACROSS MUCH OF THE AREA STILL IN THE LOW TO MID
70S...DEWPOINTS IN THE UPPER 60S...AND HIT-AND-MISS THUNDERSTORMS
POPPING UP ALL NIGHT WITHIN A MOISTURE RICH 30 KT LLJ. RESPONSIBLE
FOR ALL OF THIS IS A BROAD TROUGH OVER WRN CANADA WITH ITS AXIS
DIPPING DOWN INTO NEVADA. THIS UPPER FEATURE WILL LIFT NE THROUGH
THE DAY...WHICH WILL HELP DRIVE THE SFC LOW OVER SE NODAK INTO NW
ONTARIO...FINALLY DRIVING THE COLD FRONT THAT HAS THREATENED TO
COME INTO THE MPX AREA THE LAST FEW DAYS THROUGH MN AND WI.
BIGGEST CHANGE NOTED WITH THE GUIDANCE...ESPECIALLY WITH RESPECT
TO THE CAMS...IS A SLOWING IN THE SPEED WITH WHICH THE FRONT MOVES
ACROSS THE AREA...SO BIGGEST CHANGE WITH THE FORECAST WAS TO PULL
CATEGORICAL POPS THIS AFTERNOON FARTHER WEST AND SLOW THEIR
DEPARTURE OUT OF THE ERN SECTIONS OF THE MPX CWA.
FOR THIS MORNING...MOST HI-RES GUIDANCES SHOW GREATEST TSRA
COVERAGE OCCURRING THIS MORNING OVER ERN MN/WRN WI AS A WAVE
CURRENTLY DOWN BY SIOUX CITY LIFTS NORTHEAST TOWARD WRN WI. THIS
ACTIVITY SHOULD LARGELY CLEAR THE MPX AREA BY NOON...WITH THE EVER
SO BRIEF BREAK IN TSRA ACTIVITY OCCURRING BEFORE STORMS LIGHT UP
ALONG THE COLD FRONT IN THE AFTERNOON. PRETTY GOOD AGREEMENT AMONG
THE CAMS THAT WE SEE DEEP CONVECTION INITIATE ALONG THE COLD FRONT
BETWEEN 19Z AND 21Z NEAR A CAMBRIDGE TO MANKATO LINE. FORCING AND
MORE LINE PARALLEL SHEAR SUPPORT WHAT THE CAMS SHOW IN THAT WE SEE
A BROKEN LINE OF STORMS DEVELOP THAT SWEEPS EAST INTO WI AROUND
21/22Z AND QUICKLY CLEARS THE ERN SECTIONS OF THE MPX AREA AROUND
2Z.
FROM THE SEVERE POTENTIAL...WE CONTINUE TO SEE MIXED SIGNALS.
MODELS ARE PRETTY CONSISTENT WITH DEVELOPING 1500-2500 J/KG OF
MLCAPE AHEAD OF THE FRONT THIS AFTERNOON THAT IS RELATIVELY
UNCAPPED AS CONTINUED HEIGHT FALLS START TO COOL THE WARM EML THAT
MOVED OVER US ON SUNDAY. PROBLEM WITH THIS THOUGH IS THIS EML IS
WHAT HAS GIVEN US VERY STEEP MID LEVEL LAPSE RATES...AND THOSE
WILL BE WEAKENING WITH THE CAP. IN ADDITION...THERE WILL STILL BE
A DISCONNECT BETWEEN THE DEEP LAYER SHEAR AND THE LOW LEVEL SHEAR.
THE DEEP SHEAR WILL BE LAGGING BEHIND THE FRONT SOME...WITH THE
LOW LEVEL SHEAR PUSHING EAST WITH THE LLJ THIS EVENING. LOOKING AT
CAMS...PROBABILITIES FOR UH GREATER THAN 25 M/S IS GREATEST AROUND
SE MN/NE IA/SW WI...WHICH IS WHERE THE GREATEST DESTABILIZATION IS
EXPECTED AND HAPPENS TO COINCIDE WITH WHERE THE SPC HAS A 5%
TORNADO THREAT. WITH QUESTIONS ABOUT AMOUNT OF CLEARING AND
DESTABILIZATION WE SEE ALONG WITH THE WEAKER MID LEVEL LAPSE
RATES...WE MAY NOT SEE QUITE AS ROBUST UPDRAFTS AS WE HAVE MANAGED
THIS MORNING...BUT THE SEVERE RISK SEEMS WARRANTED...WITH THE CIPS
SEVERE ANALOGS CONTINUING TO SHOW 4 OF THE 15 ANALOG EVENTS THAT
PRODUCED SLIGHT RISK OR GREATER WORTHY SEVERE REPORTS.
FOR TONIGHT...WE WILL QUIET DOWN PRETTY QUICK IN THE WAKE OF THE
FRONT...WITH DEWPOINTS FALLING BACK INTO THE 40S...THOUGH WE LOOK
TO ONLY HAVE ENOUGH TIME TO GET TEMPS DOWN INTO THE 50S BEFORE
DIURNAL WARMING KICKS IN FRIDAY MORNING. ANY RAIN COMING IN WITH
THE SYSTEM FOR FRIDAY WILL COME AFTER 12Z FRIDAY...SO HAVE THE
REST OF THE SHORT TERM DRY ONCE WE CLEAR THE COLD FRONT OUT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CDT THU SEP 17 2015
FRIDAY AND FRIDAY NIGHT...POTENT CDFNT WILL BE LOCATED OVER LK
MICHIGAN SNAKING SWWD OVER SRN WI INTO NE IA...WELL E OF THE WFO
MPX CWFA. THIS WILL ALLOW MUCH COOLER AIR TO INFILTRATE THE REGION
AS HIGH TEMPS WILL ONLY HIT THE LOW-MID 60S FRI AFTN. A SECONDARY
WEAK LOW PRES CENTER WILL DEVELOP OVER THE WRN DAKOTAS DURG THE
DAY ON FRI...IN ADVANCE OF A KICKER SHTWV H5 TROF MOVG EWD WITHIN
FAIRLY PROGRESSIVE ZONAL FLOW ALOFT. A SWATH OF MID-UPR LVL
MOISTURE WILL ACCOMPANY THE SFC LOW BUT DRIER AIR AT THE SFC WILL
MITIGATE HIGH QPF AMOUNTS ALONG WITH THE PROGRESSIVE NATURE OF
THIS SYSTEM. PLUS...INSTABILITY WILL BE AT A MINIMUM SO WILL OMIT
THUNDER FROM THIS PORTION OF THE FCST. COVERAGE LOOKS TO ONLY BE
SCATTERED SO 30-50 POPS WILL GENERALLY SUFFICE...ALTHOUGH THE
TRACK OF THE SYSTEM FROM THE SRN DAKOTAS OVER SRN MN DOES WARRANT
SOME LIKELY POPS NEAR THE IA BORDER. THIS SYSTEM QUICKLY SHIFTS
INTO WI FRI NIGHT...ALLOWING ANY AND ALL PRECIP TO COME TO AN END
BY DAYBREAK SAT MRNG.
SATURDAY THROUGH MONDAY...HIGH PRES WILL MAKE ITS WAY INTO THE
REGION OVER THE WEEKEND THROUGH MONDAY OF NEXT WEEK. MAINLY CLEAR
SKIES AND DRIER AIR WILL BE THE RULE. IN ADDITION...SFC WINDS WILL
GRADUALLY SWING AROUND FROM NWLY ON SAT TO SLY ON SUN AND MON
WHILE A NE-SW RIDGE AXIS ALOFT SHIFTS OVER THE REGION. THE SFC
SHIFT PLUS BUILDING HEIGHTS ALOFT THROUGH THIS PERIOD WILL MEAN A
GRADUAL WARMING OF TEMPERATURES INTO EARLY NEXT WEEK. HIGHS WILL
CLIMB OUT OF THE 60S INTO THE LWR-MID 70S.
TUESDAY AND WEDNESDAY...ANOTHER COLD FRONT IS PROGGED TO PUSH THRU
THE REGION DURING THE MIDDLE OF NEXT WEEK ALTHOUGH THE TIMING AND
PHASING WITH MOISTURE IS A BIT IN QUESTION BETWEEN THE 00Z GFS AND
00Z ECMWF. THERE IS COMMONALITY BETWEEN A FRONTAL PASSAGE SO HAVE
OPTED TO INCLUDE POPS BUT NO HIGHER THAN 30 PERCENT FOR EITHER
PERIOD. HAVE ALSO SHOWN A SLIGHT DROP IN TEMPS DUE TO THE
CLOUD/RAIN COMPLICATIONS AND THE FROPA...KNOCKING HIGHS BACK DOWN
TO THE UPR 60S TO ARND 70.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 644 AM CDT THU SEP 17 2015
NUMEROUS THUNDERSTORMS WILL BE IMPACTING ERN MN/WRN WI THIS
MORNING. INHERITED TAFS CAPTURED THIS THREAT WELL AND ALL THAT WAS
NEEDED WAS TO EXTEND TEMPO GROUPS BY ABOUT AN HOUR AS STORMS
CONTINUE TO BUILD TO THE SW. WITH THE MULTIPLE ROUNDS OF
RAIN...MVFR CIGS HAVE STARTED TO APPEAR AS WELL...SO LEFT MVFR CIG
MENTION IN AS WELL FOR MSP/RNH/EAU...THOUGH THEY MAY NOT LAST AS
LONG AS CURRENTLY FORECAST...ESPECIALLY IN WI. HRRR IS STARTING TO
BACK OFF SOME ON ITS THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS
AFTERNOON...THOUGH STARTING TO GET MORE CONFIDENT ON POTENTIAL
TIMING OF STORMS WITH THE FRONT...SO NARROWED DOWN AFTERNOON TEMPOS
AT MSP/RNH/EAU. AFTERNOON ACTIVITY WILL REMAIN EAST OF
AXN/STC/RWF. BEHIND THE FRONT TONIGHT...HIGH CONFIDENCE IN WINDS
GOING NORTHWEST AND SKIES SKC.
KMSP...14Z MAY BE A LITTLE LONG FOR CARRYING A TEMPO GROUP FOR
THUNDER THIS MORNING...BUT WITH ACTIVITY CONTINUING TO DEVELOP SW
OF THE FIELD...DECIDED TO ERR ON THE SIDE OF CAUTION WITH STORMS
THIS MORNING. HRRR IS STARTING TO BACK AWAY FROM STORMS IMPACTING
MSP THIS AFTERNOON AND BASED NARROWER WINDOW FOR AFTERNOON TEMPO
GROUP ON WHEN MODELS SHOW FRONT WORKING INTO THE TWIN CITIES.
/OUTLOOK FOR KMSP/
FRI...VFR. MVFR SHRA POSSIBLE. WIND NNW 5-10 KTS.
SAT...VFR. WIND W 7-10 KTS.
SUN...VFR. WIND S 10-12 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
927 AM MDT THU SEP 17 2015
.UPDATE...
VERY LITTLE CHANGE NEEDED TO THE GOING FORECAST THIS MORNING.
WATER VAPOR IMAGERY SHOWED A STRONG SHORTWAVE AND JET DIVING INTO
THE PACIFIC NW. THE WAVE WILL PUSH INTO THE SW ZONES THIS
AFTERNOON AS WEAKER ENERGY EXITS THE E. WAVE WILL THEN MOVE
THROUGH N WY TONIGHT THROUGH FRI MORNING.
PRECIPITABLE WATERS WILL RUN AROUND A HALF INCH UNTIL THEY
INCREASE TO /0.75/ INCHES THIS EVENING OVER THE SE. Q-VECTOR
CONVERGENCE FROM THE STRONG WAVE WILL MOVE THROUGH THE AREA THIS
AFTERNOON THROUGH 18Z FRI BRINGING INCREASING CHANCES FOR SHOWERS
TO THE REGION FROM W TO E. MODELS ALL AGREED ON LOW CAPES
/250-500 J/KG/ TODAY...BUT HAD STEEP LAPSE RATES. THEREFORE CANNOT
RULE OUT A RUMBLE OF THUNDER. LATEST RADAR SHOWED PRECIPITATION
MOVING TOWARD NW WY/BEARTOOTH/ABSAROKA MOUNTAINS...SO HAVE
INCREASED POPS THERE TO LIKELY THIS MORNING AND SPREAD LIKELIES
FURTHER N INTO KLVM AND N PARK COUNTY THIS AFTERNOON. OTHERWISE
POPS WERE IN GOOD SHAPE WITH CHANCES MOVING INTO THE CENTRAL PART
OF THE AREA AFTER 18Z.
DOT REPORTS BLOWING/DRIFTING SNOW ON THE BEARTOOTH PASS FROM
VISTA POINT TO THE MT STATE LINE AND ON THE WY SIDE OF THE PASS.
THE PASS IS CLOSED IN THESE AREAS. SNOTELS AND WEB CAMS WERE NOT
POSITIONED WELL TO PICK UP THE SNOW BUT RAP SOUNDINGS SHOWED SNOW
LEVELS OF 8000 TO 9000 FT THIS MORNING. SNOW LEVELS DROP CLOSER TO
8000 FT FRI MORNING.
TEMPERATURES SHOULD REACH THE 60S THIS AFTERNOON BASED ON MIXING
TO AROUND OR BELOW 700 MB WHERE TEMPERATURES WILL BE AROUND ZERO
DEGREES C. EXPECT A FAIR AMOUNT OF CLOUD COVER TODAY WITH THE
MOISTURE MOVING IN AHEAD OF THE WAVE...BUT RAP SOUNDINGS STILL
MIXED OUT THE LOWEST OF THE CLOUDS OVER THE SE ZONES. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND FRI...
06Z UPPER ANALYSIS PLACED THE MEAN TROUGH AXIS JUST WEST OF
MONTANA. TODAYS WAVE OF INTEREST CAN BE SEEN APPROACHING THE
WESTERN COAST OF WASHINGTON AND WILL ADVECT ESE THROUGH TODAY.
EXPECTING PRECIPITATION TO BEGIN IN THE WESTERN TERRAIN AND
FOOTHILLS AROUND 15Z AND WILL SPREAD EASTWARDS THROUGH THE
AFTERNOON. THIS WAVE SHOULD BEHAVE A LITTLE DIFFERENT THAN OUR
LAST TWO AS UPPER LEVEL TEMPS WILL BE COLDER. WE ALSO SHOULD BE A
LITTLE WARMER...BY A DEGREE OR TWO...IN THE LOWER LEVELS WHICH
SHOULD HELP OVERALL INSTABILITY. THOUGH HOW MUCH INSTABILITY WE
REALIZE WILL BE DEPENDENT ON HOW CLOUDY WE ARE. WARMER CONDITIONS
IN SOUTHEAST MONTANA AND NORTHEAST WYOMING SHOULD ALLOW MORE
INSTABILITY AND BETTER CHANCES FOR RAIN. MODELS ALSO SUGGEST THE
700MB LOW WRAPPING UP JUST EAST OF THE BIG HORN MOUNTAINS WHICH
COULD ALLOW HIGHER RAINFALL AMOUNTS IN THESE LOCATIONS.
.HIGH ELEVATION SNOWFALL IMPACTS...
BIGGEST IMPACTS WITH THIS SYSTEM INVOLVE THE POTENTIAL HIGH
ELEVATION SNOW IN THE BEARTOOTHS AND IN THE BIG HORNS. 700MB
TEMPERATURES WILL BE MUCH COOLER WITH THIS SYSTEM AND THIS WILL
BRING SNOW LEVELS DOWN TO AROUND 8000FT WITH FURTHER DECREASES TO
NEAR 7500FT POSSIBLE BY EARLY FRIDAY MORNING. THOSE WITH ANY
ACTIVITIES OR TRAVEL PLANS IN THE BEARTOOTH OR BIG HORN MOUNTAINS
SHOULD PAY VERY CLOSE ATTENTION TO RAPIDLY CHANGING WEATHER
CONDITIONS THIS AFTERNOON AND TONIGHT. SNOW ACCUMULATIONS ARE
FORECAST TO BE AROUND 1 TO 3 INCHES...WITH MOST OF THESE
ACCUMULATIONS ABOVE 9000 FT AND OCCURRING AFTER SUNSET WHEN
SURFACE TEMPS COOL. WE COULD SEE HIGHER ACCUMULATIONS OF 2-4
INCHES IN THE BIG HORNS AS THE 700MB LOW WRAPS UP TONIGHT AND SOME
NORTHERLY UPSLOPE WINDS...AND WRAP AROUND MOISTURE...COMBINE WITH
SOME ENHANCED LAPSE RATES ALOFT.
FOR FRIDAY UPPER LEVEL DISTURBANCE SHOULD CLEAR OUT OF EASTERN
LOCATIONS AROUND NOON AND BRING MORE TRANQUIL CONDITIONS TO THE
AREA. SHORTWAVE RIDGING SHOULD HELP INITIATE A GRADUAL WARM UP AS
WE MOVE INTO THE EXTENDED. DOBBS
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
BENIGN WEATHER APPEARS TO BE IN STORE FOR US THROUGHOUT THE
EXTENDED PERIOD. VERY WEAK SHORTWAVE ON SATURDAY WILL HAVE A DRY
AIRMASS...RISING HEIGHTS AND DOWNSLOPE WINDS TO WORK WITH...SO AM
COMFORTABLE LEAVING THE FORECAST DRY. HEIGHTS WILL CONTINUE TO
RISE W/ FLAT RIDGING SUNDAY. SHOULD SEE HIGH TEMPS INTO THE MID
70S SATURDAY AND NEAR 80F SUNDAY...WITH SOME SW-W WIND EACH DAY.
WE WILL BEGIN TO SEE THE EFFECTS OF SHORTWAVE ENERGY ACROSS SW
CANADA WHICH WILL SUPPRESS THE RIDGE MONDAY. STILL SOME TIMING
ISSUES WITH WHAT SHOULD BE A VERY WEAK FRONTAL PASSAGE EITHER
MONDAY OR MONDAY NIGHT. WOULD EXPECT ANOTHER DAY OF ABOVE NORMAL
TEMPS ON MONDAY...AND WILL SUSTAIN LOW POPS MONDAY AFTERNOON AND
NIGHT TO COVER THE WEAK FORCING ASSOCIATED WITH THE FROPA AND SOME
MID LEVEL MOISTENING. A LOW POP IS THE MOST THIS UNDYNAMIC SYSTEM
DESERVES.
MODELS ARE IN SOME DISAGREEMENT REGARDING THE POST-FRONTAL COOLING
AND THE RETURN OF RISING HEIGHTS BY NEXT TUESDAY/WEDNESDAY. ECMWF
AND CANADIAN BUILD HEIGHTS QUICKER WHEREAS THE GFS HOLDS ONTO A
BIT STRONGER PACIFIC FLOW...AND AS A RESULT THE GFS IS THE COOLER
SCENARIO. WILL STICK W/ A COMPROMISE BETWEEN THE TWO SOLUTIONS FOR
TEMPS...IE TEMPS IN THE MID 70S TO LOWER 80S...BUT WE COULD SEE A
RETURN OF MORE WIDESPREAD 80S IF WE SEE THE STRONGER RIDGING.
EITHER WAY WILL KEEP OUR CWA DRY TUESDAY/WEDNESDAY OTHER THAN SOME
LOW MOUNTAIN POPS.
ONE OTHER ITEM OF NOTE IS THE SUBTROPICAL WAVE THAT ALL MODELS
SHOW LIFTING OUT OF THE SW CONUS NEXT WEDNESDAY/THURSDAY. THE
ECWMF SUGGEST THIS ENERGY WILL IMPACT OUR REGION BY THURSDAY
WHEREAS THE GFS KEEPS IT TO OUR S/SE COURTESY OF THE MORE VEERED
FLOW. THIS WILL BE SOMETHING TO KEEP AN EYE ON.
JKL
&&
.AVIATION...
AREAS OF MVFR OR LOWER CIGS EXIST THIS MORNING ALONG AND EAST OF
A GDV-MLS LINE. THESE LOWER CIGS SHOULD GRADUALLY LIFT BY MIDDAY.
ANOTHER PACIFIC DISTURBANCE WILL BRING SHOWERS AND ISOLATED TSTMS
BEGINNING IN THE WEST THIS AFTERNOON AND SPREADING EASTWARD
THROUGH TONIGHT. AREAS OF MVFR CAN BE EXPECTED WITH THESE SHOWERS
AND MOUNTAINS WILL BECOME FREQUENTLY OBSCURED. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 065 044/068 044/073 049/080 054/081 049/076 049/079
3/T 52/W 10/B 00/U 01/U 21/B 11/B
LVM 059 038/064 038/069 044/076 049/077 044/075 043/078
6/T 61/B 10/N 00/N 02/W 22/W 11/B
HDN 069 044/070 040/075 044/081 047/082 047/079 046/082
2/T 42/W 10/B 00/U 01/U 21/B 11/B
MLS 067 046/069 045/075 048/081 053/082 049/077 049/080
0/B 43/W 00/B 00/U 01/U 21/B 11/B
4BQ 066 046/066 043/074 046/080 049/082 049/079 047/080
1/B 64/W 00/B 00/U 00/U 21/B 11/B
BHK 064 044/066 043/073 046/078 049/081 047/075 048/076
0/B 43/W 00/B 00/U 01/U 21/B 11/U
SHR 068 042/067 037/073 041/081 044/083 045/080 044/081
3/T 64/W 00/B 00/U 00/U 21/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1134 AM EDT THU SEP 17 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE ALONG THE EAST COAST WILL WEAKEN AND
MOVE EAST THIS WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE
THROUGH SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD
EAST ACROSS THE GREAT LAKES AND LOWER OHIO VALLEY ON SUNDAY AND
LINGER EARLY IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...UPDATED HOURLY AND MAX TEMPS BASED ON HRRR AND CURRENT
READINGS.
ORIGINAL...HIGH PRESSURE IN CONTROL. THE PATCHY CIRRUS IS GONE.
LOW LEVEL MOISTURE IS PROGGED TO INCREASE SLIGHTLY TODAY...JUST
ENOUGH FOR A FEW MORE FAIR WEATHER CUMULUS BUT STILL A SUNNY DAY.
TOOK YESTERDAYS HIGH TEMPERATURES AND ADDED A DEGREE TO MOST SITES
FOR THE FORECAST MAX. THE GRADIENT IS LIGHT ENOUGH AGAIN FOR A
LAKE BREEZE...ESPECIALLY FROM AROUND CLEVELAND EAST...SO TEMPS
WILL DROP BACK A COUPLE OF DEGREES AT THE LAKESHORE THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
THE MODELS CONTINUE TO SHOW THE INITIAL BATCH OF SHOWERS/STORMS
MAKING A RUN FOR THE FORECAST AREA ON FRIDAY OUT AHEAD OF THE COLD
FRONT. THE AIR MASS WILL BE RELATIVELY DRY AND STABLE BUT THERE WILL
LIKELY BE ENOUGH ELEVATED INSTABILITY TO ALLOW THE SHOWERS TO
SURVIVE AS THEY CROSS MICHIGAN AND SPREAD ACROSS THE TOLEDO AREA AND
WESTERN LAKE ERIE. NOT SURE IF IT WILL BE A FEW SPRINKLES...A FEW
HUNDREDTHS... OR RESPECTABLE SHOWERS. WILL HAVE A CHANCE OF
SHOWERS/STORMS MAINLY FOR NORTHWEST OHIO BUT CANNOT RULE OUT A
SHOWER/SPRINKLES SNEAKING ACROSS THE NORTHERN COUNTIES ON FRIDAY.
STILL SOME TIMING DIFFERENCES AMONG MODELS ON SATURDAY WITH THE
COLD FRONTAL PASSAGE BUT THE GFS AND ECMWF ARE IN RELATIVE
AGREEMENT AND USED THEIR TIMING. NOT OVERLY EXCITED ABOUT
THUNDERSTORMS...THE MID LEVEL LAPSE RATES ARE WEAK...BUT THERE IS
MODERATE SHEAR AND SOME LOW LEVEL CAPE. WE WILL PROBABLY END UP
WITH A FEW THUNDERSTORMS. IT WILL PROBABLY BE A BREEZY DAY AHEAD
OF THE FRONT.
TEMPS ARE TRICKY ON SATURDAY DEPENDING ON HOW FAST THE CLOUDS
AND SHOWERS MOVE EAST. THE FORECAST ASSUMES THERE IS TIME FOR
WARMING FOR NE OH/NW PA WITH HIGHS AROUND 80/LOWER 80S.
HIGH PRESSURE WILL BUILD IN FROM THE WEST ON SUNDAY. THE NORTHEAST
ANTICYCLONIC FLOW AND SUBSIDENCE SHOULD PROVIDE FOR PARTIAL CLEARING
ALTHOUGH SOME HIGH CLOUDS MAY LINGER. COOLER...FEELING MORE LIKE
FALL...WITH HIGHS FROM THE MID 60S TO LOWER 70S.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
IT WILL BE PREDOMINATELY DRY THROUGH THE FIRST HALF OF
THE WORK WEEK...BUT AN UPPER TROUGH AND SOME MOISTURE FEEDING INTO
THE REGION MAY BE ENOUGH FOR A FEW SHOWERS. GFS AND CANADIAN SIMILAR
IN KEEPING US DRY. THE ECMWF IS ON THE OTHER EXTREME AND PAINTS OUT
QPF. FEEL IT WILL BE HARD TO GET TOO DEEP OF MOISTURE INTO THE AREA
WITH THE SURFACE HIGH SITTING TO OUR NORTH. WILL HAVE SILENT 20
PERCENT PRECIP CHANCES ACROSS THE EASTERN HALF OF THE AREA TUESDAY
AND WEDNESDAY. TEMPERATURES REAL CLOSE TO NORMAL AND GUIDANCE TEMPS
CLUSTERED TOGETHER. TEMPS AROUND 70 ON MONDAY INCHING UP TO THE
LOWER 70S FOR WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE DRIFTS A LITTLE FURTHER EASTWARD TODAY ALLOWING US
TO PICK UP A MORE OF A BREEZE THIS AFTERNOON. SOUTHERLY WINDS MAY
GUST AROUND 15 KNOTS ACROSS THE WEST. VFR CONDITIONS CONTINUE.
TODAY MAY FEATURE A FEW CUMULUS DOTTING THE SKY. LAKE BREEZE WILL
OCCUR AT KERI. LESS CONFIDENT WITH CLE AND THE LAKE BREEZE. IT
PUSHED THROUGH ON WEDNESDAY...BUT IT LOOKS REAL CLOSE FOR TODAY
TOO. SOME MID AND HIGH CLOUDS ENTER THE PICTURE FROM THE WEST
TOWARD THE END OF THE TAF PERIOD.
OUTLOOK...NON-VFR POSSIBLE WITH SHOWERS AND A CHANCE OF
THUNDERSTORMS FRI NIGHT INTO SAT NIGHT.
&&
.MARINE...
HIGH PRESSURE IS INCHING EASTWARD...ENOUGH NOW TO GIVE A
SOUTHWEST BREEZE TODAY THROUGH FRIDAY. STILL EXPECT A LAKE
BREEZE/ONSHORE FLOW TO DEVELOP FOR THE EASTERN HALF OF THE NEARSHORE
WATERS TODAY...LESS SO FOR FRIDAY. THE LATEST TIMING TAKES A COLD
FRONT ACROSS THE LAKE DURING THE DAYLIGHT HOURS ON SATURDAY. MOST OF
THE GUIDANCE IS CLUSTERED THERE. WHAT IS ALSO FAIRLY WELL AGREED
UPON NOW IS THERE WILL BE SOME WIND BEHIND THE FRONT FOR A TIME
BEFORE THE HIGH BUILDS IN SUFFICIENTLY TO CALM THINGS DOWN. A SMALL
CRAFT ADVISORY IS LIKELY LATE SATURDAY INTO SUNDAY. WITH HIGH
PRESSURE SITTING NORTH OF THE LAKE ON MONDAY...WILL KEEP A LIGHT
NORTHEAST FLOW GOING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...TK/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
632 AM CDT THU SEP 17 2015
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 334 AM CDT THU SEP 17 2015
COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING
WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL.
UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE
NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE
EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR
WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS
AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY
NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD
THROUGH THE DAY.
SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE
RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT
AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS
CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z
FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE
ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST
CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY
EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES
ON SATURDAY.
.LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY)
ISSUED AT 334 AM CDT THU SEP 17 2015
SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE
FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH
SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF
THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS
A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON
THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT
BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER
STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW
WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED
AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS
GIVEN BY SUPERBLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 631 AM CDT THU SEP 17 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTHWEST WINDS
WILL DIMINISH THIS EVENING AND BECOME LIGHT AND VARIABLE OVERNIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...WISE
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
613 AM CDT THU SEP 17 2015
.AVIATION...
/12Z TAFS/
Early this morning, stratus with ceilings around 2000 feet persist at
all terminals except KABI and KBBD. The morning stratus will lift
after 14z, with VFR conditions expected area-wide for the
remainder of the TAF period. Gusty south winds in the 20 to 25
knot range will also develop by late morning/early afternoon
before subsiding after sunset.
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT THU SEP 17 2015/
SHORT TERM...
(Today and Tonight)
Very little change today from what we experienced yesterday. The
upper level ridge will remain parked over the area, and may
strengthen just a tad. 850mb temperatures also warm a degree or so,
so have gone with highs of a degree or two warmer generally. Low
clouds have already begun making their way into the Concho Valley
early this morning, and so we will likely see another day with a
field of stratocumulus or cumulus clouds across much of the area.
The HRRR tries to produce a few showers in our southeastern
counties, but with the upper level high strengthening a bit, there
shouldn`t be enough coverage to mention anything in the forecast, if
they even develop. We will see another mild night with lows in the
upper 60s to lower 70s and southerly winds of 5 to 15 mph.
20
LONG TERM...
(Friday through Wednesday)
Above normal temperatures are forecast across West Central Texas on
Friday as an upper level ridge remains centered across Central
Texas. Highs will generally be in the mid to upper 90s, with
overnight lows mainly in the lower 70s.
An upper level trough will move across the Plains on Friday, sending
a cold front into the northern Big Country Saturday morning.
Previous GFS/ECMWF models runs indicated the front stalling south of
Interstate 20, across the northern Concho Valley or Heartland.
The 00z runs are less aggressive, keeping the front across the Big
Country. Although the farther south solution is still possible,
PoPs were reduced slightly across much of the region, especially
for areas south of Interstate 20. The best chance of showers and
thunderstorms looks to be across the northern Big Country. Rain
chances will linger into Sunday, mainly across the Big Country,
with the remnant front still in the area. Highs this weekend will
range from the mid and upper 80s across much of the Big Country,
to the upper 80s to lower 90s elsewhere.
Upper level ridging will build back across West Central Texas next
week. This will result in a return of above normal temperatures and
generally dry conditions.
Daniels
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 95 73 96 72 / 0 0 0 20
San Angelo 96 72 97 72 / 0 0 0 5
Junction 94 70 94 71 / 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Aviation: Doll
AREA FORECAST DISCUSSION
NWS SEATTLE WA
330 AM PDT THU SEP 17 2015
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING RAIN AT TIMES TO
WESTERN WASHINGTON THIS MORNING BEFORE TAPERING TO SHOWERS THIS
AFTERNOON. THE TROUGH WILL SHIFT EAST TONIGHT WITH RESIDUAL SHOWERS
AND A PUGET SOUND CONVERGENCE ZONE POSSIBLE. DRIER CONDITIONS ARE
LIKELY FRIDAY THROUGH SATURDAY NIGHT...THOUGH SYSTEMS BRUSHING THE
AREA COULD BRING A LITTLE RAIN TO THE FAR NORTH AND COAST AND TIMES.
ANOTHER FRONT WILL ARRIVE SUNDAY AND SUNDAY NIGHT...POSSIBLY
LINGERING INTO MONDAY. DRIER WEATHER IS POSSIBLE BY TUESDAY AND
WEDNESDAY.
&&
.SHORT TERM...RADAR IS QUITE ACTIVE THIS MORNING INDICATING VIGOROUS
SHOWER BANDS ROTATING INLAND ACROSS WRN WA. HIGHEST RAIN AMOUNTS
OVERNIGHT WERE NEAR THE COAST...OVER THE OLYMPICS...AND THE
SOUTHWEST INTERIOR WITH UP TO A QUARTER INCH IN SPOTS. THE REST OF
THE INTERIOR HAS GENERALLY ONLY SEEN A TENTH OR LESS. IR SATELLITE
IMAGERY SHOWS THE COLDEST CLOUD TOPS ASSOCIATED WITH A SHORT WAVE
NEARING THE WA/OREGON COASTS. MODEL SURFACE BASED LI`S SUGGEST
THUNDERSTORMS SHOULD MOSTLY REMAIN OVER THE COASTAL WATERS.
HOWEVER...A DOPPLER INDICATED MESO CONVECTIVE FEATURE WITH EMBEDDED
LIGHTNING STRIKES MAY HOLD TOGETHER AS IT MOVES ONTO INLAND NEAR
GRAYS HARBOR WITHIN THE NEXT HOUR OR TWO. WILL ADD A MENTION OF
THUNDER TO JUST THE SOUTH CENTRAL PORTION OF THE COAST FOR THIS
MORNING. RAIN AT TIMES WILL PERSIST ELSEWHERE UNTIL THE TROUGH AXIS
MOVES INLAND THIS AFTERNOON WITH PRECIPITATION BECOMING MORE
SCATTERED. HIGHS TODAY WILL REMAIN IN THE 60S.
SHOWERS WILL DECREASE THIS EVENING WITH LOSS OF DIURNAL INSTABILITY
AND THE TROUGH AXIS MOVING EAST. THE SURFACE RIDGE PATTERN WEST OF
PUGET SOUND WILL FAVOR A PUGET SOUND CONVERGENCE ZONE WHICH COULD
LINGER IN THE FAVORED SEATTLE TO EVERETT CORRIDOR TONIGHT.
500 MB HEIGHTS RISE ON FRIDAY BY THE FLOW IS STILL NWLY AND MORE
ZONAL THAN PAST RUNS. THE 06Z GFS SHOWS SOME LIGHT QPF OVER THE
COAST AND NORTH WHICH IS SOMEWHAT OF AN OUTLIER COMPARED TO OTHER
DRIER MODELS. WILL STILL KEEP SOME LOW POPS FOR THE NORTH COAST AND
OLYMPICS/N CASCADES BUT DRY ELSEWHERE. ONSHORE FLOW WILL BE WEAKER
BUT CLOUDS WILL STILL BE AROUND TO SOME EXTENT HOLDING BACK
TEMPERATURES. HIGHS STRUGGLING TO REACH 70 INLAND.
FRIDAY NIGHT AND SATURDAY LOOK LIKE A DRIER PERIOD WITH A SOMEWHAT
STRONGER RIDGE. THE MAIN MOISTURE FLOW WILL BE AIMED AT B.C. BUT
STILL BRUSHING THE FAR NORTH PART OF WA AT TIMES...ESPECIALLY THE
NORTH COAST. KEPT SOME LOW CHANCE POPS NORTH OF EVERETT DURING THIS
PERIOD. AROUND GREATER PUGET SOUND...PARTLY TO MOSTLY CLEAR SKIES
ARE EXPECTED WITH SLIGHT WARMING INTO THE LOW 70S SATURDAY.
.LONG TERM...EXTENDED MODELS CONTINUE TO HAVE DIFFICULTY WITH THE
TIMING AND STRENGTH OF SYSTEMS FROM SUNDAY INTO THE MIDDLE OF NEXT
WEEK. THE LATEST 00Z GFS/ECMWF AT LEAST GENERALLY AGREE ON A
STRONGER FRONT PUSHING THROUGH WRN WA LATER SUNDAY OR SUNDAY NIGHT
WITH A ROUND OF RAIN FOR MOST THE AREA. QPF AMOUNTS AND TIMING STILL
REMAIN FAIRLY UNCERTAIN. LIGHT RAIN OR SHOWERS MAY LINGER INTO
MONDAY...THEN MOST MODELS NOW POINT TOWARD A GRADUAL DRYING TREND.
ANOTHER FRONT MAY APPROACH THE COAST BY LATER WEDNESDAY. MERCER
&&
.AVIATION...AN UPPER LEVEL TROUGH OVER THE COASTAL WATERS AT 09Z
WILL MOVE INLAND OVER W WA THIS MORNING AND E OF THE CASCADES AROUND
18Z. CIGS REMAIN VFR OVC030-070 IN -RA BUT ARE EXPECTED TO LOWER TO
MVFR OVC010-030 THIS MORNING. THE TROUGH AXIS WILL MOVE OVER E WA
18Z WITH SLIGHTLY DRIER NW FLOW ALOFT DEVELOPING OVER W WA BEHIND
THE TROUGH. SHOWERS WILL DECREASE AND CIGS ARE EXPECTED TO LIFT TO
VFR BKN040-060 BETWEEN 20Z-00Z.
KSEA...CIGS REMAIN AROUND BKN-OVC050 THIS MORNING BUT LOWER MVFR
CIGS AROUND 2000 FT ARE STILL EXPECTED TO FORM AS THE MAIN AREA OF
RAIN MOVES N OF THE TERMINAL. THERE IS ANOTHER LINE OF SHOWERS ALONG
THE COAST AT 10Z ASSOCIATED WITH A TROUGH AXIS THAT COULD BRING A
FEW SHOWERS TO THE TERMINAL LATER THIS MORNING. CONFIDENCE IS PRETTY
GOOD THAT THERE WILL BE A PERIOD OF MVFR CIGS THIS MORNING BUT JUST
HOW LONG IS IN QUESTION. CIGS SHOULD LIFT TO VFR BKN040-060 AFTER
21Z. SURFACE WINDS WILL BE SOUTHERLY 5-10 KT. KAM
&&
.MARINE...A 1007 MB SURFACE LOW OVER THE COASTAL WATERS AROUND 2 AM
WILL MOVE INLAND THIS MORNING AND DISSIPATE. A SURFACE RIDGE WILL
BUILD OVER THE WA COAST THIS AFTERNOON...THEN CONTINUE THROUGH
SATURDAY. A SURFACE TROUGH WILL MOVE OVER THE OFFSHORE WATERS FRIDAY
AND WILL BE CLOSE AND STRONG ENOUGH TO RAISE SCA WINDS OVER THE
COASTAL WATERS BEFORE IT WEAKENS OFFSHORE.
A WARM FRONT WILL MOVE ACROSS SOUTHERN B.C. ON SATURDAY. S FLOW
SHOULD INCREASE OVER THE COAST AND N INTERIOR AND FUTURE MODEL RUNS
MAY SHOW STRONGER WINDS. THE TRAILING COLD FRONT WILL MOVE RAPIDLY
SE ACROSS W WA ON SUNDAY. THE GFS SHOWS A MODERATELY STRONG PRESSURE
GRADIENT WITH THE FRONT AND IT LOOKS LIKE THERE IS A GOOD CHANCE OF
SCA WINDS. ONSHORE FLOW INCREASES STRONGLY BEHIND THE FRONT LATE
SUNDAY AFTERNOON. THE 00Z GFS IS SHOWING 5.5 MB UIL-BLI FOR 00Z
MONDAY. IT IS PROBABLY A LITTLE EARLY BUT I OPTED TO INDICATE GALES
IN THE CENTRAL AND E STRAIT. KAM
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE. ]
PZ...NONE.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
254 AM PDT THU SEP 17 2015
.SYNOPSIS...
Today will be a cool and showery day with the best chance for
precipitation over the central and southern Idaho Panhandle. A
warming trend is expected Friday through the weekend with
temperatures climbing into the 70s Saturday and Sunday. A strong
frontal system will bring windy weather to the region on Sunday.
Next week looks dry Monday through Wednesday with near average
temperatures.
&&
.DISCUSSION...
Today through Friday night...An upper level trough off the
Washington coast will drop southeast across southern Washington,
Oregon, and central Idaho today. With this trajectory models
continue to favor rain showers along the East Slopes of the
Cascades, SE Washington, Lewiston area, Camas Prairie, and Central
Panhandle Mountains. Models continue to show some differences with
qpf totals, but have leaned more heavily towards the ECMWF
solutions which has the best handle on precip totals thus far. The
ECMWF suggests around a tenth of an inch or less in the
aforementioned areas...with only a chance of showers elsewhere.
Overall this is a decrease compared to what was previously
expected. For this afternoon models show the best instability over
the Idaho Panhandle and Camas Prairie where a slight chance of
thunderstorms is forecast over the high terrain. If any storms
occur they will be brief and short lived with cloud cover likely
be a limiting factor for storm development.
This system exits tonight bringing about drier conditions except
for possibly a few lingering showers over the Idaho Panhandle. A
moist boundary layer over NE Washington and North Idaho Panhandle
will likely lead to increasing areas of stratus and patchy fog
overnight into Friday morning. Another system passes by north of
the Canadian border Friday afternoon into Friday night. Main
impact from this will be mid and high clouds...along with a chance
of light showers or sprinkles near the Canadian border and Cascade
crest. JW
Saturday and Sunday: The evening model runs continue to forecast a
mainly dry weekend with the passage of a vigorous low pressure
system through southern Canada on Sunday. What this system lacks
in precipitation, it will compensate with wind. The brunt of the
wind will occur on Sunday as a deep surface low forms in the lee
of the Canadian Rockies north of Calgary. The tight westerly
pressure gradient will peak late in the day Sunday between the
Alberta low and high pressure along the Washington coast. Strong
momentum aloft will contribute to the windy conditions as a 120kt
jet core (at 250mb) sets up the BC/Washington border. With 850mb
winds of in the neighborhood of 30kts over central Washington to
the Idaho Panhandle, it looks like sustained winds of 20-25mph in
the afternoon with gusts to 35 mph. Blowing dust may need to be
added to the forecast especially if rain does not materialize
today. As far as precipitation chances, the Cascade crest will
have the best shot of rain (60-80 percent) with the cold frontal
passage Sunday afternoon/ evening. Chances east of the Cascades
will fall off dramatically in the strong west flow with 20-40
percent chances in the mountains along the Canadian border, and 10
percent or less in the Basin, Palouse, Spokane area.
Monday through Wednesday: Behind Sunday`s cold front, Monday looks
to be breezy in the afternoon with afternoon winds in the 10-20mph
range. Humidity levels on Monday will be considerably lower than
on Sunday, and we may see some areas flirt with Red Flag criteria
for wind and low humidity. As the winds diminish Monday night, the
dry air mass over the region combined with clearing skies will
support strong radiational cooling. Sheltered valleys in north
Idaho and northeast Washington will drop into the lower to mid
30s Tuesday and Wednesday morning. Look for large diurnal
temperature swings with places like Deer Park, Springdale, and
Republic. Morning lows in the low 30s Tuesday/Wednesday morning
climbing to near 70 in the afternoon. We are nearing the autumn
equinox, a time for big diurnal temperature swings. /GKoch
&&
.AVIATION...
06Z TAFS: Light rain expected to develop over Central and
Southeast Washington into the lower Idaho Panhandle by 10Z...spreading
to all TAF sites after 15Z. The system is splitting while coming
onshore and looks to bring very light spotty rain in the northern
Basin and northern mountains. CIGS are expected to remain
VFR at the TAF sites through 12z Thursday but there is a chance
of MVFR Ceilings after 15Z near the Cascades and over SE Washington.
Rain will transition to showers after 18z with a small chance for a
few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z.
Confidence for t-storms is low at this point. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 46 64 47 72 53 / 50 10 10 10 10 10
Coeur d`Alene 58 46 64 46 71 50 / 60 20 10 10 10 10
Pullman 58 45 67 46 72 50 / 70 10 10 0 10 10
Lewiston 63 49 73 50 77 55 / 70 10 10 0 10 0
Colville 59 45 64 45 73 48 / 30 10 10 10 10 10
Sandpoint 58 44 62 43 68 46 / 40 20 20 10 10 10
Kellogg 56 46 63 44 67 48 / 70 50 20 10 10 10
Moses Lake 67 45 72 48 77 53 / 40 10 0 0 10 10
Wenatchee 68 51 71 54 79 59 / 50 10 0 0 10 10
Omak 67 44 71 49 76 52 / 40 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
254 AM PDT THU SEP 17 2015
.SYNOPSIS...
Today will be a cool and showery day with the best chance for
precipitation over the central and southern Idaho Panhandle. A
warming trend is expected Friday through the weekend with
temperatures climbing into the 70s Saturday and Sunday. A strong
frontal system will bring windy weather to the region on Sunday.
Next week looks dry Monday through Wednesday with near average
temperatures.
&&
.DISCUSSION...
Today through Friday night...An upper level trough off the
Washington coast will drop southeast across southern Washington,
Oregon, and central Idaho today. With this trajectory models
continue to favor rain showers along the East Slopes of the
Cascades, SE Washington, Lewiston area, Camas Prairie, and Central
Panhandle Mountains. Models continue to show some differences with
qpf totals, but have leaned more heavily towards the ECMWF
solutions which has the best handle on precip totals thus far. The
ECMWF suggests around a tenth of an inch or less in the
aforementioned areas...with only a chance of showers elsewhere.
Overall this is a decrease compared to what was previously
expected. For this afternoon models show the best instability over
the Idaho Panhandle and Camas Prairie where a slight chance of
thunderstorms is forecast over the high terrain. If any storms
occur they will be brief and short lived with cloud cover likely
be a limiting factor for storm development.
This system exits tonight bringing about drier conditions except
for possibly a few lingering showers over the Idaho Panhandle. A
moist boundary layer over NE Washington and North Idaho Panhandle
will likely lead to increasing areas of stratus and patchy fog
overnight into Friday morning. Another system passes by north of
the Canadian border Friday afternoon into Friday night. Main
impact from this will be mid and high clouds...along with a chance
of light showers or sprinkles near the Canadian border and Cascade
crest. JW
Saturday and Sunday: The evening model runs continue to forecast a
mainly dry weekend with the passage of a vigorous low pressure
system through southern Canada on Sunday. What this system lacks
in precipitation, it will compensate with wind. The brunt of the
wind will occur on Sunday as a deep surface low forms in the lee
of the Canadian Rockies north of Calgary. The tight westerly
pressure gradient will peak late in the day Sunday between the
Alberta low and high pressure along the Washington coast. Strong
momentum aloft will contribute to the windy conditions as a 120kt
jet core (at 250mb) sets up the BC/Washington border. With 850mb
winds of in the neighborhood of 30kts over central Washington to
the Idaho Panhandle, it looks like sustained winds of 20-25mph in
the afternoon with gusts to 35 mph. Blowing dust may need to be
added to the forecast especially if rain does not materialize
today. As far as precipitation chances, the Cascade crest will
have the best shot of rain (60-80 percent) with the cold frontal
passage Sunday afternoon/ evening. Chances east of the Cascades
will fall off dramatically in the strong west flow with 20-40
percent chances in the mountains along the Canadian border, and 10
percent or less in the Basin, Palouse, Spokane area.
Monday through Wednesday: Behind Sunday`s cold front, Monday looks
to be breezy in the afternoon with afternoon winds in the 10-20mph
range. Humidity levels on Monday will be considerably lower than
on Sunday, and we may see some areas flirt with Red Flag criteria
for wind and low humidity. As the winds diminish Monday night, the
dry air mass over the region combined with clearing skies will
support strong radiational cooling. Sheltered valleys in north
Idaho and northeast Washington will drop into the lower to mid
30s Tuesday and Wednesday morning. Look for large diurnal
temperature swings with places like Deer Park, Springdale, and
Republic. Morning lows in the low 30s Tuesday/Wednesday morning
climbing to near 70 in the afternoon. We are nearing the autumn
equinox, a time for big diurnal temperature swings. /GKoch
&&
.AVIATION...
06Z TAFS: Light rain expected to develop over Central and
Southeast Washington into the lower Idaho Panhandle by 10Z...spreading
to all TAF sites after 15Z. The system is splitting while coming
onshore and looks to bring very light spotty rain in the northern
Basin and northern mountains. CIGS are expected to remain
VFR at the TAF sites through 12z Thursday but there is a chance
of MVFR Ceilings after 15Z near the Cascades and over SE Washington.
Rain will transition to showers after 18z with a small chance for a
few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z.
Confidence for t-storms is low at this point. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 46 64 47 72 53 / 50 10 10 10 10 10
Coeur d`Alene 58 46 64 46 71 50 / 60 20 10 10 10 10
Pullman 58 45 67 46 72 50 / 70 10 10 0 10 10
Lewiston 63 49 73 50 77 55 / 70 10 10 0 10 0
Colville 59 45 64 45 73 48 / 30 10 10 10 10 10
Sandpoint 58 44 62 43 68 46 / 40 20 20 10 10 10
Kellogg 56 46 63 44 67 48 / 70 50 20 10 10 10
Moses Lake 67 45 72 48 77 53 / 40 10 0 0 10 10
Wenatchee 68 51 71 54 79 59 / 50 10 0 0 10 10
Omak 67 44 71 49 76 52 / 40 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1147 PM PDT WED SEP 16 2015
.SYNOPSIS...
Cool and showery conditions will prevail through the week as a
series of Pacific storms move through the Inland Northwest.
Tonight into Thursday will feature our best shot of rain. Look
for a warming and drying trend over the weekend. Breezy conditions
are expected Sunday and Monday followed by mild and dry conditions
early next week.
&&
.DISCUSSION...
Late evening update just sent out based on current radar trends
and model data. Main changes were to further lower pops tonight
based on latest HRRR data which shows the best chances for rain
along the East Slopes of the Cascades, and over SE Washington and
the Camas Prairie late tonight. Satellite shows a couple waves
with one tracking towards western Washington and another over
Oregon that will track towards Central Idaho tonight. The 00z
ECMWF appears to have the best handle on this scenario with the
GFS and NAM overdone with its current precipitation totals over
western and south central Washington. JW
&&
.AVIATION...
06Z TAFS: Light rain expected to develop over Central and
Southeast Washington into the lower Idaho Panhandle by 10Z...spreading
to all TAF sites after 15Z. The system is splitting while coming
onshore and looks to bring very light spotty rain in the northern
Basin and northern mountains. CIGS are expected to remain
VFR at the TAF sites through 12z Thursday but there is a chance
of MVFR Ceilings after 15Z near the Cascades and over SE Washington.
Rain will transition to showers after 18z with a small chance for a
few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z.
Confidence for t-storms is low at this point. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 46 56 46 64 46 71 / 10 70 20 10 10 10
Coeur d`Alene 45 57 49 63 43 70 / 10 70 30 10 10 10
Pullman 45 56 45 65 44 72 / 40 70 20 10 0 10
Lewiston 51 63 49 71 50 77 / 50 80 20 10 0 10
Colville 42 58 45 65 41 71 / 10 60 20 10 10 10
Sandpoint 37 56 44 60 39 67 / 0 70 30 20 10 10
Kellogg 42 54 46 61 42 66 / 10 70 50 10 10 10
Moses Lake 48 65 45 71 47 77 / 20 40 10 0 0 10
Wenatchee 53 66 51 72 53 78 / 20 50 10 0 10 10
Omak 49 66 46 70 48 77 / 10 40 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
608 AM CDT THU SEP 17 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND FRIDAY
ISSUED AT 310 AM CDT THU SEP 17 2015
FORECAST CHALLENGE CENTERS ON CONVECTION TRENDS TODAY INTO
TONIGHT AND SEVERE POTENTIAL.
AREA RADARS SHOW LEAD CONVECTION EARLY THIS MORNING NEAR THE
MINNESOTA WISCONSIN BORDER IN THE LLJ REGION...HIGHER PWATS AND
850 MB WARM AIR ADVECTION. THIS FOCUS OF CONVECTION WILL
GRADUALLY SHIFT EASTWARD TODAY BUT MAY DIMINISH FOR A PERIOD LATER
THIS MORNING. A COLD FRONT AND MID LEVEL TROUGH WITH EVEN MORE
CONVECTION WAS OVER THE NORTHERN PLAINS AND APPROACHING THE
WESTERN GREAT LAKES REGION TODAY. SHOWERS AND STORMS WILL LIKELY
BECOME MORE WIDESPREAD BY THIS AFTERNOON OVER WESTERN WISCONSIN
AND THEN TOWARD EASTERN AREAS BY THIS EVENING AS THE INITIAL
CONVECTION MERGES WITH THE WITH THE APPROACHING NORTHERN PLAINS
SYSTEM. HRRR MODEL KEEPS THE LEAD WARM SECTOR CONVECTION AND THE
FRONTAL CONVECTION A BIT MORE SEPARATE. BLEND OF MODEL RUNS
SUGGEST A FASTER DEPARTURE TOWARD FRIDAY MORNING...WITH PERHAPS A
BREAK IN PCPN FOR MUCH OF FRIDAY. PCPN BEGINS TO SPREAD BACK INTO
THE AREA FROM SOUTHWEST TO NORTHEAST AS A SURFACE WAVE TRACKS
ALONG THE FRONTAL BOUNDARY SOUTH OF THE AREA. THE NORTHERN AREAS
ARE EXPECTED TO BE OVERALL DRY ON FRIDAY. LIFT WITH THE RRQ
REGION OF THE UPPER JET NOT EXPECTED TO AFFECT THE AREA UNTIL
AFTER FRIDAY AFTERNOON.
AS FAR AS SEVERE POTENTIAL. BEST ML CAPE VALUES OCCUR THIS
AFTERNOON OVER THE WEST HALF OF THE STATE INCLUDING CENTRAL AND
NORTH CENTRAL WISCONSIN AND TOWARD EARLY EVENING OVER EASTERN
AREAS. SHEAR WILL BE ON THE INCREASE THIS AFTERNOON AND EARLY
EVENING AS MID LEVEL WINDS INCREASE AND TURN MORE WSW AS A MID
LEVEL TROUGH OF LOW PRESSURE SLIDES ALONG THE US/CANADA BORDER.
THESE LIKELY STRONGER WINDS ALOFT WILL INTERACT WITH THE SOUTH
FLOW IN THE BOUNDARY LAYER AHEAD OF THE FRONT. THIS INCREASE IN
SHEAR AND INSTABILITY WILL PRODUCE A WINDOW OF SEVERE
POTENTIAL...BUT THE STRONGER WINDS ALOFT MAY ALSO PUSH THE STORMS
EASTWARD FASTER OVERNIGHT. THE PRIMARY ISSUE WILL BE HEAVY RAIN
DUE TO HIGHER PWATS AND DAMAGING WINDS. HAIL POSSIBLE WITH ANY
SUPER STORM DEVELOPMENT IN THE SHEARED ENVIRONMENT BUT PROGGED
FORECAST SOUNDINGS INDICATE WBZ START TO FALL BELOW 10000 FEET
WELL AFTER THE FROPA AND CONVECTION. AMOUNT OF CLOUDS TODAY WILL
OBVIOUSLY AFFECT AVAILABLE INSTABILITY. SPC HAS PAINTED A SLIGHT
RISK DAY 1 TODAY OVER ALL OF CENTRAL WISCONSIN AND PARTS OF NORTH
CENTRAL AND NORTHEAST WISCONSIN.
LAST DAY OF ABOVE NORMAL TEMPERATURES THIS WEEK FOR TODAY
FOLLOWED WITH NEAR NORMAL TEMPERATURES ON FRIDAY IN THE WAKE OF
THE COLD FRONT.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 310 AM CDT THU SEP 17 2015
A WET START TO THE EXTENDED FCST AS A STRENGTHENING SFC LOW RIDES
NE THRU THE GREAT LAKES...TRAILED BY A STRONG SHORTWAVE TROF. ONCE
THIS SYSTEM CLEARS...MEAN FLOW TO BE DOMINATED BY A STRONG BAND OF
WESTERLIES RUNNING FROM THE PAC NW E-EN INTO S-CNTRL CANADA. THIS
KEEPS MOST WEATHER SYSTEMS TO OUR NW FOR THE FIRST HALF OF NEXT
WEEK WITH TEMPS HOVERING NEAR OR SLIGHTLY ABOVE NORMAL.
MODELS CONT TO BATTLE WITH THE INTERACTION OF A STRENGTHENING AREA
OF LOW PRES RIDING NE ALONG THE CDFNT AND THE APPROACH OF A STRONG
SHORTWAVE TROF/EMBEDDED SHORTWAVES FRI NGT. THE NAM REMAINS
STRONGEST/FARTHEST WEST WITH THE TRACK OF THE SFC LOW...ALTHO THE
ECMWF HAS TRENDED CLOSER TO THE NAM SOLUTION THAN 24 HOURS AGO.
THE GFS/GEM ARE WEAKER/BIT FARTHER EAST WITH THE LOW TRACK. MODELS
DO AGREE ON TWO MAIN AREAS OF PCPN WITH ONE STAYING TO OUR SOUTH
ASSOCIATED WITH STRONG ISEN LIFT AND THE OTHER MOVING THRU WI
ASSOCIATED WITH THE PRIMARY DEFORMATION ZONE. DESPITE THE MODEL
DIFFERENCES...IT APPEARS THAT THE SE HALF OF WI COULD RECEIVE A
HEALTHY RAINFALL FRI NGT WITH LOCALLY HEAVY RAINS POSSIBLE. MIN
TEMPS TO RANGE FROM THE 45-50 DEG RANGE NORTH...LWR TO MID 50S
SOUTH.
THE BIGGER FCST ISSUE MAY ACTUALLY BE WHEN TO END THE PCPN CHCS ON
SAT AS THE SLOWER NAM WOULD KEEP SHWRS GOING ALL DAY AS OPPOSED TO
THE SHWRS ENDING BY MIDDAY ON THE OTHER MODELS. HAVE CONTINUED TO
LEAN TOWARD THE MAJORITY SOLUTION MAINLY DUE TO THE PROGRESSIVE
NATURE OF THE MEAN FLOW. THEREFORE...WL KEEP POPS IN THE FCST THRU
SAT MORNING AND TREND TOWARD DECREASING CLOUDS IN THE AFTERNOON.
MAX TEMPS ARE EXPECTED TO DIP SLIGHTLY BELOW NORMAL WITH READINGS
GENERALLY IN THE LWR TO MID 60S NORTH...MID TO UPR 60S SOUTH.
HI PRES IS FCST TO MOVE EAST FROM THE CNTRL PLAINS TOWARD SRN
SECTIONS OF THE GREAT LAKES SAT NGT. MOSTLY CLEAR TO PARTLY CLOUDY
SKIES...LIGHT WINDS AND A DRIER AIR MASS WL ALLOW FOR TEMPS TO
FALL TO AROUND 40 DEGS OVER THE COLDER LOCATIONS OF THE
NORTHWOODS...AROUND 50 DEGS ALONG LAKE MI. DEPENDING ON HOW MUCH
RAIN FALLS FRI NGT/SAT MORNING...THERE COULD BE PATCHY FOG
DEVELOPING JUST ABOUT ANYWHERE OVER NE WI. THE SFC HI WL DRIFT
ACROSS THE GREAT LAKES ON SUNDAY WITH A RETURN FLOW DEVELOPING
OVER WI. IN ADDITION...MODELS SUGGEST A WEAK SHORTWAVE TROF WL
APPROACH THE GREAT LAKES SUNDAY AFTERNOON. THERE IS NOT ENUF LIFT/
FORCING/MOISTURE FOR ANY PCPN TO DEVELOP...HOWEVER WE MAY SEE SOME
CLOUDS PUSH INTO THE FCST AREA THROUGHOUT THE DAY. MAX TEMPS
SHOULD BE CLOSE TO SEASONAL NORMALS WITH PLENTY OF UPR 60S TO LWR
70S.
THIS WEAK SHORTWAVE TROF PUSHES ACROSS WI WITH ITS PASSING CLOUDS
SUNDAY NGT...THEN THE MODELS BRING RISING UPR HEIGHTS INTO THE
REGION ON MON AS SOUTHERLY WINDS TO PREVAIL. MORE SUNSHINE ON MON
WL HELP NUDGE TEMPS UP A TAD WITH READINGS RANGING FROM AROUND 70
DEGS TO THE LWR 70S. QUIET WEATHER CONDITIONS TO PREVAIL THRU TUE
WITH UPR RIDGING OVER THE WRN GREAT LAKES. MODELS DO SHOW A MODEST
CDFNT PUSHING ACROSS THE UPR MS VALLEY ON TUE...BUT BE TOO FAR
AWAY YET TO IMPACT OUR WEATHER. LOOK FOR MAX TEMPS TUE TO RANGE
FROM THE UPR 60S NEAR LAKE MI...TO THE LWR TO MID 70S OVER PARTS
OF CNTRL WI.
THE MOVEMENT OF THIS CDFNT WL ULTIMATELY DETERMINE WHEN TO PLACE
THE NEXT CHC FOR SHWRS/TSTMS INTO THE FCST. FULLY ANTICIPATE THE
MODELS TO WAFFLE ON NOT ONLY THE LOCATION OF THE FNT...BUT ALSO
HOW MUCH MOISTURE WL BE AVAILABLE WHEN THE FNT DOES ARRIVE. HAVE
FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH ONLY BRINGS A
MINIMAL POP TO N-CNTRL WI TUE NGT AND WED.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 608 AM CDT THU SEP 17 2015
ISOLATED SHOWERS AND STORMS MAY BRUSH OVER FAR NORTH
CENTRAL WISCONSIN OR AREAS NORTHWEST OF RHI THIS
MORNING...OTHERWISE VFR CONDITIONS FOR MUCH OF THE AREA FOR THE
START OF TODAY. LLWS CONDITIONS WILL LINGER THIS MORNING BEFORE
GUSTY SOUTH SURFACE WINDS DEVELOP. SHOWERS AND STORMS ALONG WITH
SCATTERED MVFR CONDITIONS WILL BE ON THE INCREASE TODAY AND
EVENING THEN DIMINISHING FROM WEST TO EAST LATE TONIGHT. SOME
STRONG OR SEVERE STORMS ARE POSSIBLE IN THE AFTERNOON AND EARLY
EVENING. OVERNIGHT...AREAS OF IFR CIGS/VSBYS MAY BE DEVELOPING
ALONG AND IN THE WAKE OF THE COLD FRONT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1235 PM EDT THU SEP 17 2015
.SYNOPSIS...
DRY HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE EASTERN
SEABOARD... WHILE LOW PRESSURE MEANDERS OFFSHORE...ENSURING
GENERALLY FAIR WEATHER FOR OUR FORECAST AREA THROUGH THE WEEKEND.
A FRONT ALONG WITH AN UPPER LOW IS EXPECTED TO LEAD TO INCREASED
PRECIPITATION CHANCES EARLY TO MID NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED
TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN
ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE
FORECAST AREA. THE HRRR DISPLAYS JUST ISOLATED SHOWERS IN THE
EAST PART THIS AFTERNOON. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING
MAY RESULT IN STRATUS LATE TONIGHT. THE GFS AND NAM MOS INDICATE
LOW CLOUDINESS DEVELOPING. THE TEMPERATURE GUIDANCE WAS
CONSISTENT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NT/...
WEAK UPPER TROUGH NEAR OUR REGION WILL MOVE VERY SLOWLY TO THE
EAST...WITH LOW PRESSURE DEVELOPING OFFSHORE AND MOVING VERY
SLOWLY OFFSHORE. BEST ATMOSPHERIC MOISTURE WILL REMAIN EAST OF OUR
FORECAST AREA (FA)...THOUGH A GENERALLY ONSHORE LOW LEVEL FLOW
MAY RESULT IN INCREASING MOISTURE PENETRATING SLIGHTLY INLAND TO
PERHAPS GIVE OUR SE FA A SLIGHT CHANCE OF A SHOWER. GUIDANCE
INDICATING A CONTINUED SLIGHT WARMING TREND...WITH TEMPS REACHING
BACK UP TO NEAR OR JUST ABOVE CLIMO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
LITTLE CHANGE SUNDAY. WEAK HIGH PRESSURE TO REMAIN OVER THE MID
ATLANTIC AND CAROLINAS WHILE UPPER AND SURFACE LOW REMAIN
OFFSHORE. AN UPPER DISTURBANCE AND FRONT WILL MOVE ACROSS THE
GREAT LAKES/MIDWEST REGION...WITH SURFACE HIGH PRESSURE BEHIND IT
BUILDING INTO NEW ENGLAND SUN/MON. MODELS INDICATE NEXT UPPER
TROUGH MOVING ACROSS THE NORTHERN TIER OF STATES...CUTTING OFF
JUST TO OUR WEST BY TUE/WED. MEANWHILE OLD UPPER TROUGH AND
SURFACE LOW CONTINUE TO MEANDER OFFSHORE. ALL THIS APPEARS TO LEAD
TO POSSIBLE BACK DOOR FRONT MOVING SOUTH INTO OUR REGION EARLY TO
MID WEEK...WITH INCREASING MOISTURE AND PRECIPITATION
CHANCES...AND POSSIBLE WEAK WEDGE DEVELOPMENT. ACCEPTED BLEND OF
GUIDANCE...INDICATING INCREASED POPS AND LOWER MAX TEMPS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.
HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED
TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN
ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE
TERMINALS. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN
RESTRICTIONS DURING THE EARLY MORNING HOURS FRIDAY. THE NAM AND
GFS MOS INDICATE MVFR OR IFR CONDITIONS DEVELOPING.
EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS IN FOG AND STRATUS
POSSIBLE EACH MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1234 PM CDT THU SEP 17 2015
.UPDATE...
ISSUED AT 1045 AM CDT THU SEP 17 2015
At 1035am broken clouds are covering parts of eastern IL late this
morning. HiRes/short range models continue to show some scattered
light pcpn in the east, but just over the next couple of hours.
Believe those models not handling pcpn fields well, as they do not
have the larger area of pcpn in central and eastern Iowa. So will
making some adjustments to pops and removing slight chances for
the area and then adding some chance pops late this afternoon in
the northwest to account for area in eastern IA possibly spreading
south into extreme northwestern parts of the cwa. Remainder of
forecast looks fine. Update will be out shortly.
&&
.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT THU SEP 17 2015
The approaching cold front from the Plains will cause increasing
southerly flow in the lower troposphere, raising moisture levels
across the forecast area. Warm air advection showers are already
nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP
models show spotty showers advancing across our counties west of I-
55 this morning. Most spots will just see sprinkles, but a few
locations could get measurable rain under convective updrafts.
Therefore, we advanced slight chance PoPs into the western counties
over several hours this morning, then diminished just after Noon. A
return of slight chances for Knox and Stark counties is expected
after 3 pm/20z as a shortwave/low pressure begin to move northeast
along the front into Iowa.
Depending on cloud cover, high temps should climb to at or above
yesterdays very warm readings in the mid to upper 80s in the west,
with mid 80s in the east. Held off on low 90s, due to periodic cloud
cover limiting full warming potential.
South winds will become gusty today ahead of the cold front, with
sustained speeds of 15-20 mph, and gusts into the mid to upper 20
mph range this afternoon.
.LONG TERM...(TONIGHT THROUGH Wednesday)
ISSUED AT 335 AM CDT THU SEP 17 2015
Beyond today, the remaining of the forecast has a lot of agreement
in the models overall. The precipitation chances increase tonight
as the front gets closer to the region. The front slows a bit
tomorrow as it runs into mostly parallel flow out of the southwest,
but starts to break down the ridge over the eastern half of the
country. There is the potential for a bit of a break on Friday...but
that will depend highly on mesoscale features and cloud cover during
the day...and keeping the forecast to chance pops a a result. The
second wave is expected to bring increasing pops tomorrow night with
the actual fropa and wind shift coming in the early morning hours
for Saturday. Northwesterly winds for Saturday and lower max temps
in the upper 60s in the northern portions of the state, Central
Illinois in the 70s. More widespread 70s expected for Sunday
afternoon to wrap up the weekend. So far, the mid level temps in
the models are not pointing to a deep chill behind the cold front.
Although a few degrees below normal briefly, a general warming trend
will have Central Illinois back to climatological norms by midweek.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1234 PM CDT THU SEP 17 2015
Challenging forecast for the TAFs this afternoon as models not
handling ongoing pcpn all that well and lots of uncertainty with
what will transpire tonight. Thinking that current pcpn in eastern
IA will remain north of PIA/BMI this afternoon/evening. Believe
trend will be for line of showers and storms to move through the
TAFs after midnight. So will keep VFR conditions going this
afternoon with scattered clouds around 5kft. Then broken mid
clouds around 12kft, remnants of convection to the northwest, will
advect into the area this evening. Will then bring vcts into the
TAFs starting at 06z at PIA and then progressing eastward
overnight...lasting about 3hrs at each site. Then by morning,
scattered clouds around 5kft and a broken mid deck is expected.
winds should remain southerly through the period with gusts this
afternoon, just over 20kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1248 PM CDT THU SEP 17 2015
...Update to aviation forecast discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU SEP 17 2015
An upper level trough was deepening across the eastern Pacific and
the western CONUS at 08Z. A stronger shortwave trough was moving
onshore into Washington state while an upper level ridge continued
across the southern Plains into the western Gulf with southwesterly
upper flow across the Central Plains. A few embedded waves were
moving across the Northern Plains early this morning. Isentropic
lift in the 315K-320K layer was developing a few isolated showers in
north central and northeast Kansas. Short range hi resolution
models, including the experimental HRRR show isolated to scattered
elevated convection across the forecast area, but mainly focusing
across northeast Kansas by sunrise. A frontal boundary was located
from central South Dakota to a low pressure area in southwest
Nebraska then into eastern Colorado. A trough moving across the
Northern Plains today should push the front southeast into north
central Kansas later this afternoon then extend from Hiawatha to
Abilene by late evening. The front looks to stall out across the
forecast area after midnight from northwest Missouri into south
central Kansas. Expect the isolated showers and thunderstorms
through the morning hours before moving off to the northeast. Expect
a break for much of the afternoon as there is little in the way of
any lift and convergence along the front is expected to be weak and
forecast soundings show EML capping surface convection for the
afternoon. That said convective inhibition will begin to wane late
in the day and have maintained increasing pops along the frontal
zone. Tonight the low level jet will be orientated parallel to the
frontal boundary with the pooling of moisture near the front,
especially in northeast Kansas initially before shifting to the
southeast through the night. Isentropic lift and convergence are
also initially focused in the northeast and into northwest Missouri
then shifts southward through the night into east central Kansas.
Shear and instability will be sufficient for a few strong to severe
storms tonight. Locally heavy rainfall is also possible where storms
train along the boundary. Mixing to around 850 mb today will make
for highs in the upper 80s to mid 90s. Lows tonight will cool into
the 60s north of the front and lower 70s to its south.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 340 AM CDT THU SEP 17 2015
By Friday morning, the cold front should be stretched across the
southeastern portion of the CWA and lift a bit to the north through
the morning hours. This front finally will progress eastward through
the afternoon and evening hours as the secondary mid-level trough
sweeps into the Northern and Central Plains, thus helping to push
this system eastward out of the area. Models show that we may lose
some of the available lift during the morning hours on Friday, so
there may only be some scattered morning showers and thunderstorms.
However, thunderstorm potential looks to increase during the
afternoon hours and into the evening as the forcing/lift increases
across the area with the progressing front and support from the mid-
level trough approaching the area. Soundings show the cap
potentially eroding away by mid-afternoon, when the front should be
nearly bisecting the CWA from southwest to northeast. This available
lift/forcing combined with limited inhibition by mid-afternoon, CAPE
values increasing to upwards of around 2000 J/kg, and 0-6 km bulk
shear values increasing to at least 35-40kts, should result in the
potential for some severe thunderstorm development mid Friday
afternoon into Friday evening. While the primary hazards will be
damaging winds and large hail, 0-1 km shear and helicity values
suggest even the potential for a few isolated tornadoes as well.
While these afternoon storms should be a bit more progressive, with
PWAT values in the 1.7-1.9 inch range and the low/mid level jets
expected to be nearly parallel to the boundary, cannot rule out the
potential for some locally heavy rain that could potentially lead to
some localized flash flooding. The severe threat should diminish by
late evening with a dry forecast in place for the entire CWA by the
overnight hours (early Saturday morning).
Surface high pressure will surge into the central U.S. behind the
exiting system, ushering cooler air into the region. Have continued
to trend a bit cooler for high temperatures on Saturday as northerly
winds may only allow afternoon highs to reach into the low/mid 70s.
Lows Saturday night should drop into the low 50s. Winds will shift
around to the southeast by Sunday, pushing highs a few degrees
higher into the mid/upper 70s. Models continue to show an embedded
shortwave trough developing within the mid-level flow over the
central U.S. on Sunday, however the best moisture and lift look to
remain further south of the CWA so have kept a dry forecast for
Sunday.
A mid-level ridge will build back into the Southern and Central
Plains by early next week. With surface high pressure shifting east
of the area, southerly winds will help to gradually moderate high
temperatures into the low/mid 80s by Tuesday. Models start diverging
in their solutions by mid-week as the GFS develops an embedded wave
along the western ridge axis that could potentially result in some
precipitation skimming the CWA, while the ECMWF keeps the area dry.
While confidence is low in the precip potential, have only some low-
end slight chance PoPs in for Wednesday night into Thursday.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1236 PM CDT THU SEP 17 2015
Expect VFR conditions this afternoon at all terminals. This
evening, an unsettled period will enter into the forecast. Low
confidence in areas of thunderstorm development have prompted the
mention of VCTS. Do believe that there will be essentially two
periods of storms, so have not used a blanket VCTS for the entire
period. The general trend and model consensus does appear to hint
towards a slow Eastward progression of the low and associated
boundaries over the next 24 hours or so. This led to opting not
to carry a storm chance for the KMHK terminal after the 12z time
frame. It still remains possible that subsequent forecasts may
need to insert storms back into the forecast for the morning.
Additionally, with the overall synoptic setup in place, not
expecting the LLJ to be as strong over the terminals and therefore
not as concerned that windshear will be a major impact at this
time.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
636 PM EDT THU SEP 17 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE AS A COLD FRONT MOVES OUT OF THE
MIDWEST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BE THE CONTROLLING FACTOR
FOR OUR WEATHER OVERNIGHT...EVEN AS THE CENTER OF THE HIGH STARTS
TO MOVE EAST OF THE APPALACHIAN FRONT. WHILE THIS WILL ALLOW FOR
SOUTH GRADIENT FLOW FROM THE SOUTHWEST IN THE LOW LEVELS...SURFACE
OBSERVATIONS AND RAP SOUNDINGS ALREADY INDICATE DIURNAL MIXING IS
WANING. AS A RESULT...SURFACE FLOW WILL LIKELY DROP TO NIL WITHIN
THE NEXT COUPLE OF HOURS. THIS WILL YIELD CLEAR SKIES OVERNIGHT
DUE TO A DEARTH OF LAYER MOISTURE...AND VERY WEAK BOUNDARY LAYER
FLOW. THIS WILL BASICALLY MEAN THAT TEMPERATURES WILL HAVE THEIR
EYES SET ON THE DEWPOINTS FORTHWITH AS THEY FALL AGGRESSIVELY INTO
THE LATER EVENING. AND DUE TO THE LENGTH IN THE NIGHTS GOING INTO
THE FALL...DIURNAL DROPS AFTER A WARM DAY GET TO BE EASIER TO
ACCOMPLISH.
THE ONLY INFINITESIMALLY DIFFICULT PART OF THE FORECAST IS HOW TO
HANDLE THE DEWPOINT FORECAST. THERE IS A WINDOW OF SLIGHTLY LOWER
DEWPOINTS IN EASTERN INDIANA AND WESTERN OHIO...WHERE VALUES ARE
STRADDLING THE 50F MARK. HRRR GUIDANCE IS EXHIBITING ITS TYPICAL
DRY AFTERNOON BIAS DUE TO IRRATIONAL MIXING...AND WITH INVERSIONS
READY TO SET UP FAIRLY SHORTLY...THE WINDOW FOR GETTING DRIER AIR
INTO THE BOUNDARY LAYER IN OUR CWA IS QUICKLY CLOSING. THIS LEAVES
US WITH GENERALLY LOWER TO MIDDLE 50S ACROSS THE CWA...AND WHILE A
BIT OF THAT MOISTURE MAY BE REMOVED BY DEW DEPOSITION...IT SEEMS
UNLIKELY THAT LOWS WILL BREACH 50F ON AN ORGANIZED BASIS MUCH OF
ANYWHERE EXCEPT IN THE LOWEST VALLEYS AMONGST THE RIDGES. THERMAL
BELTS WILL LIKELY BE PRONOUNCED IN THE HIGHER TERRAIN...MUCH LIKE
LAST NIGHT...YIELDING INVERTED TEMPERATURE GRIDS OVER THE RIDGES.
ELSEWHERE...THE URBAN HEAT ISLAND SEEMS LIKELY TO BE A BIT
STRONGER AROUND PITTSBURGH THAN LAST NIGHT DUE TO THE INSOLATION
TODAY...HOWEVER OUTSIDE OF THERE...LOWS WILL PROBABLY ONLY BE UP A
COUPLE OF DEGREES FROM LAST NIGHT. FRIES
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE LAST COUPLE MODEL RUNS HAVE PRODUCED SOME LIGHT PRECIP WITH A
LEAD SHORTWAVE MOVING OUT OF THE MIDWEST LATE ON FRIDAY. HAVE
DECIDED TO INCLUDE A SLIGHT PRECIP PROB OVER EXTREME NWRN...AND
WRN ZONES FOR THIS FEATURE...ALTHOUGH LOW LEVEL LAYERS ARE LIKELY
TO BE SLOW MOISTENING SUFFICIENTLY. MAY END UP MORE OF A SPRINKLE
SITUATION. OTHERWISE...AN AFTERNOON AND EVENING MID LEVEL CLOUD
INCREASE CAN BE EXPECTED.
THE BETTER PRECIP CHANCE WILL STILL BE WITH THE LATE SATURDAY COLD
FRONT...POPS FOR WHICH WERE INCREASED AND ADJUSTED FOR THE QUICKER
TIMING OF THE LATEST GFS AND NAM TRENDS. NUMBERS WERE STILL
LIMITED TO THE CHANCE CATEGORY FOR NOW GIVEN OMEGA BULLSEYE
QUESTIONS AND EXPECTATIONS THAT MODEL-WORLD BOUNDARY MOISTURE MAY
BE TOO HIGH. PROGGED INSTABILITY IS THUS ALSO LIKELY TO BE
HIGH...AND WOULD NOT SUPPORT SEVERE STORMS DESPITE THE INCREASING
DEEP LAYER SHEAR IN THE TIGHTENING PRESSURE GRADIENT.
PASSAGE OF THE FRONT WILL DROP TEMPS BACK TO THE SEASONAL AVERAGES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
BUILDING HIGH PRESSURE IS THEN PROJECTED TO BRING DRY AND
SEASONAL CONDITIONS SUNDAY AND MONDAY. THEREAFTER...FORECAST
CONFIDENCE DROPS QUICKLY AS DIFFERING MODEL SOLUTIONS PROVIDE NO
CLEAR PICTURE FOR THE END OF THE LONG TERM. THE FORECAST WAS THUS
BASED ON PERSISTENCE WITH ONLY MINOR CHANGES TO TUESDAY AND
WEDNESDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MAINTAIN VFR WITH EXCEPTIONS OF BRIEF DAWN FOG.
HAVE GONE WITH PERSISTENCE FORECASTS FROM THIS MORNINGS
OBSERVATIONS AT HLG/FKL/DUJ.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
THE NEXT CHANCE FOR GENERAL RESTRICTIONS WILL COME WITH A LATE
SATURDAY COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
530 PM EDT THU SEP 17 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE AS A COLD FRONT MOVES OUT OF THE
MIDWEST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BE THE CONTROLLING FACTOR
FOR OUR WEATHER OVERNIGHT...EVEN AS THE CENTER OF THE HIGH STARTS
TO MOVE EAST OF THE APPALACHIAN FRONT. WHILE THIS WILL ALLOW FOR
SOUTH GRADIENT FLOW FROM THE SOUTHWEST IN THE LOW LEVELS...SURFACE
OBSERVATIONS AND RAP SOUNDINGS ALREADY INDICATE DIURNAL MIXING IS
WANING. AS A RESULT...SURFACE FLOW WILL LIKELY DROP TO NIL WITHIN
THE NEXT COUPLE OF HOURS. THIS WILL YIELD CLEAR SKIES OVERNIGHT
DUE TO A DEARTH OF LAYER MOISTURE...AND VERY WEAK BOUNDARY LAYER
FLOW. THIS WILL BASICALLY MEAN THAT TEMPERATURES WILL HAVE THERE
EYES SET ON THE DEWPOINTS FORTHWITH AS THEY FALL AGGRESSIVELY INTO
THE LATER EVENING. AND DUE TO THE LENGTH IN THE NIGHTS GOING INTO
THE FALL...DIURNAL DROPS AFTER A WARM DAY GET TO BE EASIER TO
ACCOMPLISH.
THE ONLY INFINITESIMALLY DIFFICULT PART OF THE FORECAST IS HOW TO
HANDLE THE DEWPOINT FORECAST. THERE IS A WINDOW OF SLIGHTLY LOWER
DEWPOINTS IN EASTERN INDIANA AND WESTERN OHIO...WHERE VALUES ARE
STRADDLING THE 50F MARK. HRRR GUIDANCE IS EXHIBITING ITS TYPICAL
DRY AFTERNOON BIAS DUE TO IRRATIONAL MIXING...AND WITH INVERSIONS
READY TO SET UP FAIRLY SHORTLY...THE WINDOW FOR GETTING DRIER AIR
INTO THE BOUNDARY LAYER IN OUR CWA IS QUICKLY CLOSING. THIS LEAVES
US WITH GENERALLY LOWER TO MIDDLE 50S ACROSS THE CWA...AND WHILE A
BIT OF THAT MOISTURE MAY BE REMOVED BY DEW DEPOSITION...IT SEEMS
UNLIKELY THAT LOWS WILL BREACH 50F ON AN ORGANIZED BASIS MUCH OF
ANYWHERE EXCEPT IN THE LOWEST VALLEYS AMONGST THE RIDGES. THERMAL
BELTS WILL LIKELY BE PRONOUNCED IN THE HIGHER TERRAIN...MUCH LIKE
LAST NIGHT...YIELDING INVERTED TEMPERATURE GRIDS OVER THE RIDGES.
ELSEWHERE...THE URBAN HEAT ISLAND SEEMS LIKELY TO BE A BIT
STRONGER AROUND PITTSBURGH THAN LAST NIGHT DUE TO THE INSOLATION
TODAY...HOWEVER OUTSIDE OF THERE...LOWS WILL PROBABLY ONLY BE UP A
COUPLE OF DEGREES FROM LAST NIGHT. FRIES
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE LAST COUPLE MODEL RUNS HAVE PRODUCED SOME LIGHT PRECIP WITH A
LEAD SHORTWAVE MOVING OUT OF THE MIDWEST LATE ON FRIDAY. HAVE
DECIDED TO INCLUDE A SLIGHT PRECIP PROB OVER EXTREME NWRN...AND
WRN ZONES FOR THIS FEATURE...ALTHOUGH LOW LEVEL LAYERS ARE LIKELY
TO BE SLOW MOISTENING SUFFICIENTLY. MAY END UP MORE OF A SPRINKLE
SITUATION. OTHERWISE...AN AFTERNOON AND EVENING MID LEVEL CLOUD
INCREASE CAN BE EXPECTED.
THE BETTER PRECIP CHANCE WILL STILL BE WITH THE LATE SATURDAY COLD
FRONT...POPS FOR WHICH WERE INCREASED AND ADJUSTED FOR THE QUICKER
TIMING OF THE LATEST GFS AND NAM TRENDS. NUMBERS WERE STILL
LIMITED TO THE CHANCE CATEGORY FOR NOW GIVEN OMEGA BULLSEYE
QUESTIONS AND EXPECTATIONS THAT MODEL-WORLD BOUNDARY MOISTURE MAY
BE TOO HIGH. PROGGED INSTABILITY IS THUS ALSO LIKELY TO BE
HIGH...AND WOULD NOT SUPPORT SEVERE STORMS DESPITE THE INCREASING
DEEP LAYER SHEAR IN THE TIGHTENING PRESSURE GRADIENT.
PASSAGE OF THE FRONT WILL DROP TEMPS BACK TO THE SEASONAL AVERAGES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
BUILDING HIGH PRESSURE IS THEN PROJECTED TO BRING DRY AND
SEASONAL CONDITIONS SUNDAY AND MONDAY. THEREAFTER...FORECAST
CONFIDENCE DROPS QUICKLY AS DIFFERING MODEL SOLUTIONS PROVIDE NO
CLEAR PICTURE FOR THE END OF THE LONG TERM. THE FORECAST WAS THUS
BASED ON PERSISTENCE WITH ONLY MINOR CHANGES TO TUESDAY AND
WEDNESDAY.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MAINTAIN VFR WITH EXCEPTIONS OF BRIEF DAWN FOG.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...
THE NEXT CHANCE FOR GENERAL RESTRICTIONS WILL COME WITH A LATE
SATURDAY COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
325 PM EDT THU SEP 17 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 320 PM EDT THU SEP 17 2015
MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
REGION...STARTING AS EARLY AS THIS EVENING AND CONTINUING
OVERNIGHT. ANOTHER ROUND OF STORMS LOOKS LIKELY FRIDAY NIGHT INTO
SATURDAY MORNING WITH SOME HEAVY RAINS EXPECTED. SOME FLOODING
COULD OCCUR WHERE STORMS PERSIST. COOLER AND BREEZY CONDITIONS
MOVE IN SATURDAY BEFORE A WARMING TREND STARTS AGAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 320 PM EDT THU SEP 17 2015
THE TWO PRIMARY RISKS TO EVALUATE THROUGH SATURDAY MORNING WILL BE
DAMAGING WIND GUST POTENTIAL ALONG WITH LOCALIZED FLOODING. FOR
THIS EVENING...ALMOST ALL NUMERICAL GUIDANCE IS STRUGGLING WITH
THE CONVECTION ACROSS NORTHERN IL. ONLY THE HRRR HAS A CLUE ABOUT
CONVECTIVE TRENDS AT THIS POINT AND SUGGESTS THE RAIN WILL PROCEED
ACROSS THE LAKE THIS EVENING AND WEAKEN A BIT...IN SPITE OF SPC
SREF-BASED EFFECTIVE BULK SHEAR INCREASING OVER THE LAKE (THOUGH
CIN WILL BE GROWING TOWARD NIGHTFALL). BUMPED POPS UP THIS EVENING
ESPECIALLY NEAR/WEST OF US 131 TO INCLUDE THIS THREAT FOR STORMS
IN CASE THEY SURVIVE THE TRIP OVER THE LAKE. NOT EXPECTING ANY
SEVERE WEATHER WITH THIS.
LATER TONIGHT...LOOKS LIKE A LINE OF STORMS WILL SOLIDIFY ACROSS
EASTERN WI IN THE MIDST OF A MID LEVEL SHORTWAVE APPROACHING BY
06Z AND A 40 KT LLJ ADVECTING MOISTURE INTO THE REGION. THIS LINE
FORMS ALONG A WEAK COLD FRONT WHICH WILL SLOW DOWN AND STALL OUT
OVER THE HEART OF THE CWA FRIDAY. RAIN CHANCES LOOK QUITE LIKELY
OVERNIGHT THOUGH INSTABILITY LOOKS WEAK OR NONEXISTENT FOR MOST
PLACES. WITH ONLY MODEST WINDS ACROSS THE COLUMN...WOULD EXPECT
LITTLE OR NO SEVERE WEATHER WITH THIS ACTIVITY OVERNIGHT. THE
BIGGER THREAT WOULD BE LOCALLY HEAVY DOWNPOURS...MAYBE UP TO AN
INCH IN SPOTS. AREAS THAT GET THE HEAVIEST RAIN WOULD BE FAVORED
FOR A FLOOD THREAT FRIDAY NIGHT GIVEN MOIST SOILS AND HENCE SOME
FAVORABLE ANTECEDENT CONDITIONS.
THE SEVERE WEATHER THREAT DOES GO UP FRIDAY...ESPECIALLY IN THE
EVENING AND LASTING THROUGH THE NIGHT. DAMAGING WIND GUSTS AND
SOME FLOODING ARE BOTH POTENTIAL HAZARDS. THE SFC COLD FRONT WILL
STALL OVER THE REGION FRIDAY AND BECOME A WARM FRONT BY EVENING.
WITH AN INCREASING LLJ TO 50 KTS...THERE WILL BE VERY GOOD
MOISTURE CONVERGENCE SETTING UP ALONG THIS FRONT...LEADING TO SOME
HEAVY RAINS. UPPER LEVEL DIVERGENCE WILL BE INCREASING BY 00Z
FRIDAY...AND WITH THE RIGHT ENTRANCE REGION OF THE JET APPROACHING
THE DEEP LAYER SHEAR WILL INCREASE...ESPECIALLY ACROSS CENTRAL
LOWER MI. EVEN THE STRONG LLJ ALONE WOULD SUGGEST SOME DAMAGING
WIND POTENTIAL. GIVEN THE WARM FRONT NEARBY...A BOOST TO THE 0-1
KM STORM RELATIVE HELICITY CAN BE EXPECTED...AND THE ECMWF SHOWS
THIS NICELY WITH VALUES APPROACHING 200-250 M2/S2 BETWEEN 00Z-06Z
SAT. GIVEN RELATIVELY LOW CAPE...THE SEVERE WEATHER POTENTIAL
WILL NOT BE AS HIGH AS IT COULD BE. EVEN SO...INCREASING DEEP
LAYER SHEAR MAY HELP OFFSET THIS AND STILL SUPPORT SOME STRONG TO
SEVERE THUNDERSTORMS.
OUR MODEL BLENDED QPF FEATURES 1"-2" THROUGH SATURDAY. HOWEVER...
LOCALIZED HEAVY RAINFALL RATES OF 1"/HR OR MORE ARE QUITE
POSSIBLE GIVEN THE NATURE OF THIS SYSTEM (HIGH PW VALUES FOR MID
SEPTEMBER AND DEW POINTS CLIMBING INTO THE UPPER 60S). SOME
PONDING ON ROADS IS POSSIBLE OVERNIGHT AND MAYBE FOR THE MORNING
COMMUTE. FLOODING OF ROADS IN A SHORT TIME IS A THREAT
FRIDAY/FRIDAY NIGHT WHERE HEAVIER STORMS SET UP. THIS THREAT COULD
BE A GREATER HAZARD TO MOTORISTS AND IT MAY LINGER INTO SATURDAY
MORNING.
&&
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 PM EDT THU SEP 17 2015
I THINK WE WILL NEED TO WATCH THIS FORECAST CLOSELY IN THE COMING
DAYS. WILL MAINTAIN THE DRY PERIOD FOR NOW.
THE MAIN CONCERN IS THAT MODELS ARE IN DECENT AGREEMENT IN
KEEPING AN UPPER TROUGH OVERHEAD. THIS MAY SUPPORT SOME
INSTABILITY TYPE SHOWERS. AT THE SURFACE HIGH PRESSURE IS IN
PLACE. SUBSIDENCE WITH THIS FEATURE SHOULD LIMIT THE SHOWER/STORM
RISK.
SLOW MODERATION OF THE TEMPERATURES IS FORECASTED BECAUSE THE LOW
LEVEL THERMAL TROUGH GENERALLY STAYS IN PLACE. TEMPERATURES ARE
LIKELY TO END UP FAIRLY CLOSE TO SEASONABLE. THE WARMEST DAYS WILL
LIKELY BE BE THURSDAY AS A LOW LEVEL THERMAL RIDGE TRIES TO SET UP
OVER THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 142 PM EDT THU SEP 17 2015
A BAND OF SHOWERS AND THUNDERSTORMS WILL TRACK THROUGH THE TAF
SITES OVERNIGHT FROM WEST TO EAST. THEY SHOULD REACH KMKG ROUGHLY
AROUND MIDNIGHT. IMPACTS ARE EXPECTED WITH AT LEAST MVFR AT ALL
SITES...ALTHOUGH A BRIEF PERIOD OF IFR COULD OCCUR. THE STORMS
SHOULD PUSH EAST OF KJXN BY 14Z FRI. WITH A VERY MOIST AIRMASS IN
PLACE...MVFR FOG SHOULD LINGER THROUGH THE MORNING.
&&
.MARINE...
ISSUED AT 320 PM EDT THU SEP 17 2015
&&
.HYDROLOGY...
ISSUED AT 206 PM EDT THU SEP 17 2015
RAIN OF ONE TO TWO INCHES EXPECTED TONIGHT INTO SATURDAY MORNING...
AHEAD OF AND WITH A FRONTAL BOUNDARY EXPECTED TO STALL OVER THE
AREA. NO FLOODING ISSUES ARE EXPECTED THROUGH FRIDAY. LEVELS ARE
FALLING OR STEADY ON ALL AREA RIVERS. LOCALLY OVER 2 INCHES OF RAIN
ARE POSSIBLE AND MAY LEAD TO PONDING OF WATER IN SOUTHWEST LOWER
MICHIGAN FRIDAY INTO THE WEEKEND. ISOLATED AREAS MAY ALSO SEE SOME
STREET AND SMALL STREAM FLOODING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY MORNING FOR MIZ037-043-
050-056.
LM...GALE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY AFTERNOON FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT FRIDAY FOR LMZ846>849.
&&
$$
SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...MJS
AVIATION...MJS
HYDROLOGY...63
MARINE...HOVING
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
310 PM CDT THU SEP 17 2015
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT THU SEP 17 2015
COLD FRONT IS PROGRESSING THROUGH THE MID-MISSOURI VALLEY REGION
TODAY. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES BROAD
SOUTHWESTERLY FLOW ACROSS THE WESTERN AND CENTRAL US...WITH TROUGH
AXIS FROM OR THROUGH NV/CA...AND WITH NORTHERN STREAM TROUGH NEAR
THE AB/SASK BORDER TO MT. 500MB HEIGHT FALLS UP TO 50M WERE NOTED
IN THE NORTH CENTRAL US. 850MB COLD FRONT EXTENDED FROM THE ONT/MB
BORDER THROUGH THE ND/MN AND SD/MN BORDER...INTO CENTRAL TO
SOUTHWEST NEB. AHEAD OF THE FRONT...AIRMASS WAS MOISTURE
RICH...WITH DEWPOINTS OF 12C+ FROM THE MO VALLEY TO THE WESTERN
GREAT LAKES...AND WITH 40-50KT WEST-SOUTHWESTERLY WINDS. 700-500MB
TEMPERATURE DIFFERENCE WAS MAXIMIZED OVER NEB...AT THE NOSE OF THE
700MB THERMAL RIDGE. SURFACE COLD FRONT AT 19Z EXTENDED FROM
SURFACE LOW IN WESTERN ONT...THROUGH CENTRAL MM...TO NEAR KDNS...TO
KOMA...TO SECONDARY SURFACE LOW IN NORTH CENTRAL KS. ALONG AND
AHEAD OF THE FRONT...CU FIELD HAD DEVELOPED...WITH DEWPOINTS IN THE
UPPER 60S TO LOWER 70S. BEHIND IT...DEWPOINTS WERE IN THE 50S WITH
QUICKLY CLEARING SKIES.
MAIN FORECAST CONCERN IS CONVECTIVE DEVELOPMENT THIS
AFTERNOON/EVENING...AND RAIN CHANCES TOMORROW. FRONT CONTINUES TO
ADVANCE THROUGH THE CWA. AHEAD OF IT...CONVECTIVE DEVELOPMENT IS
POSSIBLE THIS AFTERNOON...THOUGH NOT YET IMMINENT AS CU FIELD IS
VISUALLY SHALLOW WITH NO ECHOES YET ON RADAR. RAP ANALYSIS
INDICATES ABOUT 3000 J/KG UNCAPPED MLCAPE AHEAD OF THE FRONT...BUT
MOST OF THE BULK SHEAR IS BEHIND THE FRONT. WITH THAT
INSTABILITY...ANY STORMS THAT POP UP COULD BECOME BRIEFLY
SEVERE...BUT THINK THEY MAY BE ON THE PULSY SIDE GIVEN THE
MISALIGNED DEEP-LAYER SHEAR. FRONT IS MAKING FAIRLY RAPID
PROGRESS...AND HAVE SPED THE EXIT OF STORMS IN THE SOUTH AND LOWERED
POPS IN ALL BUT THE SOUTHERNMOST/SOUTHEASTERNMOST FRINGE OF THE CWA
FOR THIS EVENING.
FROM EARLY FRIDAY MORNING THROUGH THE AFTERNOON...UPPER-LEVEL TROUGH
ADVANCES THROUGH THE NORTHERN ROCKIES AND TOWARD THE PLAINS...WITH
LEE SURFACE LOW DEEPENING AND SLIDING ACROSS THE FRONTAL BOUNDARY
THROUGH KS AND INTO NORTHERN MO/SOUTHERN IA. MOST OF THE CWA WILL
BE WELL NORTH OF THE LOW...AND AS BAROCLINIC ZONE ON THE NORTHERN
SIDE DEVELOPS AND RAIN DEVELOPS/EXPANDS...THINK WE MAINLY WILL SEE
JUST DREARY RAIN AND PERHAPS A LITTLE EMBEDDED THUNDER...WITH A
COUPLE OF THUNDERSTORMS POSSIBLE IN THE FAR SOUTHERN CWA IF
ANYWHERE. RAIN SHOULD SHIFT EAST/SOUTHEAST OF THE CWA THROUGH THE
AFTERNOON...WITH MOST OF THE AREA RAIN-FREE BY AROUND 00Z.
HIGH PRESSURE WILL FOLLOW ON THE HEELS OF THE SYSTEM AND INFLUENCE
THE AREA THROUGH SATURDAY...WITH QUIET AND COOLER WEATHER FRIDAY AND
SATURDAY BEFORE TEMPERATURES MODERATE TOWARD NORMAL ON SUNDAY.
RETURN FLOW ON SATURDAY NIGHT MAY SPARK A FEW SHOWERS/STORMS IN
CENTRAL/WESTERN NEB ON SATURDAY NIGHT INTO SUNDAY MORNING...BUT
THINK THIS ACTIVITY WILL STAY WEST OF THE CWA.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CDT THU SEP 17 2015
RETURN FLOW CONTINUES INTO THE PLAINS INTO THE WORK WEEK...WITH AN
UPPER-LEVEL RIDGE BUILDING INTO THE PLAINS THROUGH TUESDAY AND
BRINGING MODERATING TEMPERATURES...BEFORE GIVING WAY TO
SOUTHWESTERLY FLOW AS IT FLATTENS. AROUND WEDNESDAY/WEDNESDAY
NIGHT...THE NEXT UPPER-LEVEL TROUGH TO PUSH ACROSS THE PLAINS WILL
BRING A COLD FRONT AND ASSOCIATED SHOWER/THUNDERSTORM CHANCES. FRONT
DOES NOT APPEAR TO HAVE A STRONG COLD PUSH THOUGH...AND NEAR TO
ABOVE AVERAGE TEMPERATURES SHOULD CONTINUE THROUGH THURSDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1229 PM CDT THU SEP 17 2015
AS OF 17Z...COLD FRONT EXTENDED FROM JUST EAST OF KOFK...TO KFET
TO KHJH. SOME SCT TO MVFR BKN CU WAS IN THE VICINITY OF THE FRONT
AND WINDS WERE SHIFTING TO THE NORTH NORTHWEST BEHIND THE FRONT.
EXPECT SHOWERS AND THUNDERSTORMS TO FORM IN ADVANCE OF THE COLD
FRONT BUT SHOULD REMAIN EAST OF ALL THREE TAF SITES THIS AFTERNOON
AND EVENING. AFTER 14Z WINDS WILL BECOME NORTHEAST ON THE BACKSIDE
OF THE COLD FRONT WHICH IS A GOOD FLOW TO PRODUCE RAIN AND FOG.
HAVE ADDED A TEMPO GROUP TO ALL THREE TAF SITES TO HINT AT THIS
POSSIBILITY LATE IN THE FORECAST PERIOD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...MAYES
AVIATION...MEYER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
424 PM EDT THU SEP 17 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH ON FRIDAY BEFORE PUSHING THROUGH THE
OHIO VALLEY ON SATURDAY...ALLOWING FOR SHOWERS AND PERHAPS A FEW
THUNDERSTORMS. HIGH PRESSURE AND COOLER TEMPERATURES WILL BUILD IN
BEHIND THE FRONT ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SURFACE RIDGE WILL EXTEND WEST BACK INTO THE UPPER OHIO VALLEY
OVERNIGHT WHILE A COLD FRONT SLOWLY SAGS SOUTHEAST TO THE WESTERN
GREAT LAKES. IT SHOULD START OFF MAINLY CLEAR THIS EVENING.
THEREAFTER...CLOUDS WILL INCREASE FROM THE NORTHWEST OVERNIGHT DUE
TO UPSTREAM CONVECTION. MODELS CONTINUE TO INDICATE THAT AN
EMBEDDED S/WV...MODEST LOW LEVEL JET...AND FRONTAL ZONE WILL
PRODUCE PCPN TO OUR WEST/NORTHWEST OVERNIGHT...WEAKENING THE
COVERAGE AS IT MOVES SOUTHEAST TOWARD SUNRISE. THERE COULD BE A
FEW SHOWERS THAT SNEAK IN TO OUR FAR NORTHWEST ZONES BY MORNING.
OTHERWISE...THE EAST/SERN CWFA WILL REMAIN MOSTLY CLEAR. LOWS
WILL VARY FROM THE LOWER 50S IN THE COOLER LOCATIONS OF EAST
CENTRAL AND SOUTH CENTRAL OHIO TO THE LOWER 60S FAR NORTHWEST DUE
TO LIGHT SOUTHERLY WINDS AND INCREASING CLOUDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
HAVE USED A BLEND OF THE GFS AND ECMWF FOR THE SHORT TERM
FORECAST.
COLD FRONT WILL MOVE A LITTLE FARTHER SOUTHEAST ON FRIDAY BUT
WILL REMAIN WELL TO OUR NORTHWEST. THERE COULD BE CONSIDERABLE
CLOUDS DURING THE MORNING HOURS RESULTING FROM PREVIOUS NIGHTS
CONVECTION TO OUR NORTHWEST. AGAIN...A FEW SHOWERS MAY BE SKIMMING
OUR NORTHWEST ZONES DURING THE MORNING. IT LOOKS LIKE ANY
SHOWER/THUNDERSTORM ACTIVITY WILL REMAIN CLOSER TO THE FRONT FOR
THE AFTERNOON HOURS. TEMPERATURES WILL BE CLOUD DEPENDENT BUT
SHOULD WARM INTO THE LOWER AND MID 80S ONCE AGAIN.
FOR FRIDAY NIGHT...POTENT S/WV WITHIN THE FLOW ALOFT WILL EJECT
NORTHEAST TO THE GREAT LAKES. A STRONG LLJ WILL TEAM UP WITH
FAVORABLE UPR DIV FROM THE RR QUAD OF AN UPR LVL JET TO PERTURB A
WAVE LOW PRESSURE ON THE FRONT. WIDESPREAD PCPN IS EXPECTED FROM
NRN IL...SRN WI...NRN IND...SRN MI AND THEN INTO NW OHIO. OUR AREA
WILL BE ON THE PERIPHERY OF THE BEST LOW LEVEL FORCING SO ONLY
HAVE CHANCE POPS IN THE FORECAST FOR THE NW TAPERING OFF TO A DRY
FORECAST MAINLY ALONG AND SOUTHEAST OF I-71. OVERNIGHT LOWS WILL
BE MAINLY IN THE 60S.
ON SATURDAY...AS WAVE OF LOW PRESSURE PASSES BY TO OUR NORTHEAST...
ATTENDANT COLD FRONT THEN WILL MOVE THROUGH OUR AREA. THE FRONT
WILL INTERACT WITH FAIRLY HIGH PWATS. HOWEVER...LIFT WILL BE
MAINLY FROM LOW LEVEL FRONTAL CONVERGENCE ALONG AND AHEAD OF THE
FRONT. WE SHOULD AT LEAST SEE LIKELY POPS FOR OUR WESTERN HALF OF
THE CWFA...BUT FRONTAL CONVERGENCE SEEMS TO WEAKEN AS IT MOVES
THROUGH THE REMAINDER OF THE AREA SATURDAY AFTERNOON AND
EVENING...SO HAVE CHANCE POPS ELSEWHERE. THERE SHOULD BE ENOUGH
INSTABILITY FOR EMBEDDED THUNDER.
BY SATURDAY NIGHT...THE COLD FRONT WILL EXIT TO OUR SOUTHEAST...
ALLOWING SURFACE HIGH PRESSURE TO BUILD IN FROM THE NORTHWEST.
DRIER AND COOLER WEATHER WILL FILTER INTO THE REGION. LOWS WILL
BOTTOM OUT IN THE UPPER 40S NORTH TO THE MID 50S ALONG AND SOUTH
OF THE OHIO RIVER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AT THE START OF THE EXTENDED FORECAST PERIOD...A COLD FRONT WILL BE
JUST SOUTHEAST OF THE ILN FORECAST AREA...WITH HIGH PRESSURE
BUILDING INTO THE SOUTHERN GREAT LAKES AND NORTHERN OHIO VALLEY.
THIS HIGH WILL BE FAIRLY DRY...PROVIDING A MOSTLY SUNNY DAY ON
SUNDAY...WITH HIGHS IN THE LOWER TO MID 70S.
THE FOCUS GOING INTO THE FIRST HALF OF THE WEEK WILL BE ON THE
FORMATION OF AN AREA OF UPPER LEVEL LOW PRESSURE...WHICH WILL
DEVELOP AS THE SURFACE HIGH TRANSLATES NORTHEAST. AT THE SAME
TIME...A SSW-TO-NNE ORIENTED SURFACE TROUGH WILL DEVELOP JUST WEST
OF THE APPALACHIAN MOUNTAINS...WITH MOISTURE AND PRECIPITATION
SPREADING ALONG THE MOUNTAINS AND INTO THE UPPER OHIO AND TENNESSEE
VALLEY REGIONS BY MONDAY NIGHT. THERE IS DECENT AGREEMENT BETWEEN
THE 12Z GFS/ECMWF THROUGH TUESDAY...AND BOTH MODELS SUGGEST THAT
MOST OF THE PRECIPITATION WILL REMAIN EAST OF THE ILN FORECAST AREA.
THUS...POPS HAVE BEEN SLIGHTLY LOWERED FROM THE PREVIOUS
FORECAST...WITH ONLY SLIGHT CHANCES OF SHOWERS EXPECTED ON MONDAY
AND TUESDAY (PERHAPS A LITTLE MORE LIKELY ON TUESDAY). WITH MODELS
INDICATING RELATIVELY STABLE CONDITIONS...THUNDER SEEMS UNLIKELY.
MODEL SPREAD INCREASES SIGNIFICANTLY BY WEDNESDAY...PRIMARILY WITH
REGARD TO THE LOCATION AND STRENGTH OF THE UPPER LOW. THE 12Z
OPERATIONAL RUNS LOOK VASTLY DIFFERENT TODAY THAN THEY DID
YESTERDAY. GFSE MEMBERS ARE SHOWING A POSITIONAL SPREAD OF AROUND
400 MILES WITH REGARDS TO THE CENTER OF THE UPPER LOW BY 12Z
WEDNESDAY MORNING...AND ARE SPREAD OUT ENOUGH BY WEDNESDAY EVENING
THAT THE ENSEMBLE MEAN IS SO DAMPENED AS TO MISS THE PRESENCE OF THE
CLOSED LOW ENTIRELY. THUS...THE FORECAST BEYOND TUESDAY IS OF VERY
LOW CONFIDENCE. A GRADUAL WARMING TREND THROUGH THE WEEK WILL BE
FORECAST...WITH TEMPERATURES RETURNING TO NEAR NORMAL BY THE MIDDLE
OF THE WEEK.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
FEW TO SCATTERED CU ARE EXPECTED AGAIN THIS AFTERNOON BEFORE
MIXING OUT BEFORE SENT.
SFC HIGH PRESSURE WILL FINALLY GIVE WAY TONIGHT...RETREATING A
LITTLE TO THE EAST. AS THIS OCCURS A H5 S/W WILL PUSH INTO THE WRN
GREAT LAKES AFT 00Z. AREA OF CONVECTION IS FORECAST TO PUSH E
THROUGH NRN ILLINOIS INTO NRN INDIANA AND POSSIBLY INTO NW OHIO
BY 12Z. A CIRRUS CIG IS EXPECTED TO WORK INTO THE TAFS AHEAD OF
THE CONVECTION. CONDITIONS SHOULD BE VFR OVERNIGHT FOR THE
TAFS...EXCEPT FOR LUK...WHERE FOG IS EXPECTED AGAIN. NOT THAT
CONFIDENT ON EXACTLY HOW LOW THE VSBYS WILL DROP WITH THE HIGHER
CLOUDS WORKING IN. TOOK LUK DOWN TO MVFR BETWEEN 06-12Z FOR NOW.
THE ABOVE MENTIONED CONVECTION WILL BE WEAKENING AS IT HEADS
EAST...BUT COULD HOLD TOGETHER FRIDAY MORNING. THREW IN A VCSH AFT
12Z AT DAY TO COVER THE POSSIBILITY OF PCPN IN THE AREA.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO/HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...CONIGLIO/HICKMAN
LONG TERM...HATZOS
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
145 PM EDT THU SEP 17 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE ALONG THE EAST COAST WILL WEAKEN AND
MOVE EAST THIS WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE
THROUGH SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD
EAST ACROSS THE GREAT LAKES AND LOWER OHIO VALLEY ON SUNDAY AND
LINGER EARLY IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...UPDATED HOURLY AND MAX TEMPS BASED ON HRRR AND CURRENT
READINGS.
ORIGINAL...HIGH PRESSURE IN CONTROL. THE PATCHY CIRRUS IS GONE.
LOW LEVEL MOISTURE IS PROGGED TO INCREASE SLIGHTLY TODAY...JUST
ENOUGH FOR A FEW MORE FAIR WEATHER CUMULUS BUT STILL A SUNNY DAY.
TOOK YESTERDAYS HIGH TEMPERATURES AND ADDED A DEGREE TO MOST SITES
FOR THE FORECAST MAX. THE GRADIENT IS LIGHT ENOUGH AGAIN FOR A
LAKE BREEZE...ESPECIALLY FROM AROUND CLEVELAND EAST...SO TEMPS
WILL DROP BACK A COUPLE OF DEGREES AT THE LAKESHORE THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
THE MODELS CONTINUE TO SHOW THE INITIAL BATCH OF SHOWERS/STORMS
MAKING A RUN FOR THE FORECAST AREA ON FRIDAY OUT AHEAD OF THE COLD
FRONT. THE AIR MASS WILL BE RELATIVELY DRY AND STABLE BUT THERE WILL
LIKELY BE ENOUGH ELEVATED INSTABILITY TO ALLOW THE SHOWERS TO
SURVIVE AS THEY CROSS MICHIGAN AND SPREAD ACROSS THE TOLEDO AREA AND
WESTERN LAKE ERIE. NOT SURE IF IT WILL BE A FEW SPRINKLES...A FEW
HUNDREDTHS... OR RESPECTABLE SHOWERS. WILL HAVE A CHANCE OF
SHOWERS/STORMS MAINLY FOR NORTHWEST OHIO BUT CANNOT RULE OUT A
SHOWER/SPRINKLES SNEAKING ACROSS THE NORTHERN COUNTIES ON FRIDAY.
STILL SOME TIMING DIFFERENCES AMONG MODELS ON SATURDAY WITH THE
COLD FRONTAL PASSAGE BUT THE GFS AND ECMWF ARE IN RELATIVE
AGREEMENT AND USED THEIR TIMING. NOT OVERLY EXCITED ABOUT
THUNDERSTORMS...THE MID LEVEL LAPSE RATES ARE WEAK...BUT THERE IS
MODERATE SHEAR AND SOME LOW LEVEL CAPE. WE WILL PROBABLY END UP
WITH A FEW THUNDERSTORMS. IT WILL PROBABLY BE A BREEZY DAY AHEAD
OF THE FRONT.
TEMPS ARE TRICKY ON SATURDAY DEPENDING ON HOW FAST THE CLOUDS
AND SHOWERS MOVE EAST. THE FORECAST ASSUMES THERE IS TIME FOR
WARMING FOR NE OH/NW PA WITH HIGHS AROUND 80/LOWER 80S.
HIGH PRESSURE WILL BUILD IN FROM THE WEST ON SUNDAY. THE NORTHEAST
ANTICYCLONIC FLOW AND SUBSIDENCE SHOULD PROVIDE FOR PARTIAL CLEARING
ALTHOUGH SOME HIGH CLOUDS MAY LINGER. COOLER...FEELING MORE LIKE
FALL...WITH HIGHS FROM THE MID 60S TO LOWER 70S.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
IT WILL BE PREDOMINATELY DRY THROUGH THE FIRST HALF OF
THE WORK WEEK...BUT AN UPPER TROUGH AND SOME MOISTURE FEEDING INTO
THE REGION MAY BE ENOUGH FOR A FEW SHOWERS. GFS AND CANADIAN SIMILAR
IN KEEPING US DRY. THE ECMWF IS ON THE OTHER EXTREME AND PAINTS OUT
QPF. FEEL IT WILL BE HARD TO GET TOO DEEP OF MOISTURE INTO THE AREA
WITH THE SURFACE HIGH SITTING TO OUR NORTH. WILL HAVE SILENT 20
PERCENT PRECIP CHANCES ACROSS THE EASTERN HALF OF THE AREA TUESDAY
AND WEDNESDAY. TEMPERATURES REAL CLOSE TO NORMAL AND GUIDANCE TEMPS
CLUSTERED TOGETHER. TEMPS AROUND 70 ON MONDAY INCHING UP TO THE
LOWER 70S FOR WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS CONTINUE AS HIGH PRESSURE SLIDES OFF TO THE EAST.
THE WIND WILL TRY AND COME AROUND NNW LATE THIS AFTN OFF THE LAKE
AT KCLE AND KERI. FARTHER WEST...AT KTOL AND KFDY...THE WIND WILL
BEGIN TO GUST FROM THE SSW THROUGH SUNSET. AFTER SUNSET ALL SITES
WILL OBSERVE S TO SW FLOW 5 KTS OR LESS. BY 12Z FRI A WEAK COLD
FRONT WILL BE LOCATED JUST WEST OF KTOL. THIS FRONT WILL WEAKEN
AS IT MOVES E ACROSS NORTHERN OH...SO ONLY MENTIONING -TSRA AT
KCLE AND KFDY STARTING AROUND 15Z...AND VCTS AT KCLE AFTER 18Z.
THE BETTER CHANCES CONTINUE TO COME AFTER THE TAF PERIOD WITH A
SECONDARY FRONT AND LOW.
OUTLOOK...NON-VFR POSSIBLE WITH SHOWERS AND A CHANCE OF
THUNDERSTORMS FRI NIGHT INTO SAT NIGHT.
&&
.MARINE...
HIGH PRESSURE IS INCHING EASTWARD...ENOUGH NOW TO GIVE A
SOUTHWEST BREEZE TODAY THROUGH FRIDAY. STILL EXPECT A LAKE
BREEZE/ONSHORE FLOW TO DEVELOP FOR THE EASTERN HALF OF THE NEARSHORE
WATERS TODAY...LESS SO FOR FRIDAY. THE LATEST TIMING TAKES A COLD
FRONT ACROSS THE LAKE DURING THE DAYLIGHT HOURS ON SATURDAY. MOST OF
THE GUIDANCE IS CLUSTERED THERE. WHAT IS ALSO FAIRLY WELL AGREED
UPON NOW IS THERE WILL BE SOME WIND BEHIND THE FRONT FOR A TIME
BEFORE THE HIGH BUILDS IN SUFFICIENTLY TO CALM THINGS DOWN. A SMALL
CRAFT ADVISORY IS LIKELY LATE SATURDAY INTO SUNDAY. WITH HIGH
PRESSURE SITTING NORTH OF THE LAKE ON MONDAY...WILL KEEP A LIGHT
NORTHEAST FLOW GOING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...TK/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...OUDEMAN
AVIATION...MAYERS
MARINE...OUDEMAN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1223 PM CDT THU SEP 17 2015
.UPDATE...
ISSUED AT 1221 PM CDT THU SEP 17 2015
SEE UPDATED AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 1118 AM CDT THU SEP 17 2015
SURFACE TROF HAS JUST ABOUT CLEARED THE CWA...ALONG WITH THE
REMAINING ELEVATED SHOWERS. HAVE INCREASED THE WINDS A
TAD...OTHERWISE NO CHANGES TO THE FORECAST AS FOCUS SHIFTS TO
TONIGHT/FRIDAYS RAIN POTENTIAL.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 334 AM CDT THU SEP 17 2015
COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING
WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL.
UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE
NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE
EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR
WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS
AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY
NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD
THROUGH THE DAY.
SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE
RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT
AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS
CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z
FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE
ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST
CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY
EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES
ON SATURDAY.
.LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY)
ISSUED AT 334 AM CDT THU SEP 17 2015
SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE
FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH
SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF
THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS
A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON
THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT
BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER
STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW
WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED
AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS
GIVEN BY SUPERBLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1221 PM CDT THU SEP 17 2015
AN AREA OF MVFR CIGS WILL TRACK ACROSS THE NORTH CENTRAL AND
NORTHEASTERN CWA THIS AFTERNOON. OTHERWISE...VFR CONDITIONS WILL
PREVAIL ACROSS THE AREA THROUGH THE TAF PERIOD. AN AREA OF RAIN
WILL SPREAD FROM WEST TO EAST LATE TONIGHT THROUGH MIDDAY FRIDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...PARKIN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1121 AM CDT THU SEP 17 2015
.UPDATE...
ISSUED AT 1118 AM CDT THU SEP 17 2015
SURFACE TROF HAS JUST ABOUT CLEARED THE CWA...ALONG WITH THE
REMAINING ELEVATED SHOWERS. HAVE INCREASED THE WINDS A
TAD...OTHERWISE NO CHANGES TO THE FORECAST AS FOCUS SHIFTS TO
TONIGHT/FRIDAYS RAIN POTENTIAL.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 334 AM CDT THU SEP 17 2015
COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING
WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL.
UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE
NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE
EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR
WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS
AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY
NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD
THROUGH THE DAY.
SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE
RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT
AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS
CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z
FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE
ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST
CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY
EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES
ON SATURDAY.
.LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY)
ISSUED AT 334 AM CDT THU SEP 17 2015
SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE
FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH
SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF
THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS
A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON
THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT
BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER
STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW
WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED
AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS
GIVEN BY SUPERBLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 631 AM CDT THU SEP 17 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTHWEST WINDS
WILL DIMINISH THIS EVENING AND BECOME LIGHT AND VARIABLE OVERNIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...WISE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1150 AM CDT THU SEP 17 2015
.DISCUSSION...HIGH PRESSURE REMAINS IN CONTROL OF OUR WEATHER, AND
OUR DRY FORECAST FOR TODAY LOOKS TO BE ON TRACK, AS DOES CURRENT
TEMP FORECAST.
LOW LEVEL MOISTURE WORKING NORTHEASTWARD OUT OF ALABAMA IS
PRODUCING A CU FIELD OF NOTE, AND CSV DEVELOPED A 4K FT CIG AT
16Z. WILL THEREFORE INCREASE CU COVERAGE IN OUR FCST GRIDS FOR
SRN AND ERN AREAS FOR THIS AFTERNOON.
LATEST HRRR PRECIP FCST FOR TODAY GIVES A VERY WEAK INDICATION OF
ISOLATED SHOWER DEVELOPMENT OVER THE SOUTH, BUT BLV SUBSIDENCE
INVERSION NEAR 780MB AND PREVAILING DRYNESS OF ATMOSPHERIC COLUMN
WILL BE STRONG ENOUGH TO KEEP SHOWERS AT BAY.
ALTHOUGH CHANGES TO GRIDS ARE MINOR, WILL GO AHEAD AND SEND OUT A
NEW SUITE OF PRODUCTS TO REFLECT LATEST DIURNAL TRENDS AND
EXPECTATIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 87 62 88 64 / 0 0 10 10
CLARKSVILLE 86 61 87 65 / 0 0 10 10
CROSSVILLE 80 56 81 59 / 0 0 10 10
COLUMBIA 86 59 87 62 / 0 0 10 10
LAWRENCEBURG 85 60 86 62 / 0 0 10 10
WAVERLY 86 61 86 64 / 0 0 10 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
246 PM CDT THU SEP 17 2015
.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
ONLY HIGHLIGHT IN THE SHORT TERM PERIOD WILL BE THE POSSIBILITY OF
LOCALIZED DENSE FOG FRIDAY MORNING FOR THE COASTAL PLAINS AND
EASTERN COUNTIES. RAIN CHANCES WILL CONTINUE TO BE LOW WITH SLIGHTLY
ABOVE NORMAL TEMPERATURES.
THE SYNOPTIC PATTERN REVEALS AN H5 RIDGE CENTERED OVER TEXAS WITH A
LONGWAVE TROUGH SHIFTING ACROSS THE NORTHERN ROCKIES WHILE ANOTHER
TROUGH IS LOCATED OVER FLORIDA. THE RIDGE OVER TEXAS WILL CONTINUE
TO BEAR ITS INFLUENCE AND PERPETUATE THE SLIGHTLY ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS. ONLY CAVEAT WILL BE ISOLATED LIGHT
SHOWERS ACROSS PORTIONS OF THE COASTAL PLAINS BUT HAVE ONLY
MENTIONED A 15% CHANCE IN THAT LOCATION THIS AFTERNOON. THESE
SHOWERS WILL DISSIPATE QUICKLY AFTER SUNSET.
LOW CLOUDS WILL DEVELOP ONCE AGAIN OVERNIGHT WITH ANOTHER LIKELY
ROUND OF FOG IN THE EASTERN AND COASTAL PLAIN COUNTIES. DEWPOINT
DEPRESSIONS WILL BE 1F OR LESS PER RAP OUTPUT WITH NEAR CALM WINDS.
SREF PROBABILITIES OF <1 MILE VISIBILITIES ARE HIGHER THEN WHAT IT
INDICATED FOR THIS MORNING ALSO. AREAS OF FOG WERE ADDED TO THE
WEATHER FORECAST WITH THE DEVELOPMENT OF DENSE FOG NEEDING TO BE
CLOSELY MONITORED. THE LOW CLOUDS AND FOG THAT DO FROM WILL
DISSIPATE OUT THROUGH THE MID TO LATE MORNING...SIMILAR TO TODAY.
ADDITIONAL CLEARING WILL OCCUR THROUGH THE AFTERNOON HOURS FRIDAY
WITH TEMPERATURES REACHING BACK INTO THE MID TO UPPER 90S.
&&
.LONG TERM (SATURDAY THROUGH THURSDAY)...
THE LONG TERM FORECAST WILL CONTINUE TO BE MAINLY DOMINATED BY AN
UPPER LEVEL RIDGE. A QUICKLY MOVING TROUGH WILL PASS NORTH OF THE
RIDGE...ACROSS THE NORTHERN PLAINS FRIDAY AFTERNOON. THIS UPPER
LOW WILL ALLOW A COLD FRONT TO MOVE INTO NORTH TEXAS SATURDAY
AFTERNOON. HOWEVER...WITH THE RIDGE IN PLACE ACROSS SOUTHERN AND
CENTRAL TEXAS...THE FRONT SHOULD STALL SOMEWHERE NEAR THE I-20
CORRIDOR. THE GFS/ECMWF BOTH ARE SHOWING SOME AFTERNOON AND
EVENING CONVECTION ALONG THE FRONT SATURDAY...BUT MOST IF NOT ALL
OF THIS SHOULD STAY TO OUR NORTH CLOSER TO THE FRONT AND WILL NOT
MENTION ANY PRECIP AT THIS TIME FOR THE NORTHERN HILL COUNTRY.
FOR THE REST OF THE EXTENDED FORECAST...MODELS ARE PROGGING
SURFACE DEWPOINTS TO LOWER INTO THE 50S AND LOWER 60S BY SATURDAY
AFTERNOON...CONTINUING EACH AFTERNOON THROUGH THE REST OF THE
PERIOD. HIGH TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 90S WITH
PLEASANT...DRY EVENINGS. LOW TEMPERATURES WILL UPPER 60S TO LOWER
70S ACROSS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 73 95 72 95 71 / 0 - 0 - -
AUSTIN BERGSTROM INTL AIRPORT 71 95 70 94 68 / 0 - 0 - -
NEW BRAUNFELS MUNI AIRPORT 73 96 72 96 69 / 0 - 0 - -
BURNET MUNI AIRPORT 72 94 71 94 69 / 0 0 0 10 -
DEL RIO INTL AIRPORT 75 97 76 96 73 / 0 0 0 - -
GEORGETOWN MUNI AIRPORT 73 95 71 94 70 / 0 0 0 - -
HONDO MUNI AIRPORT 73 96 72 96 68 / 0 0 0 - -
SAN MARCOS MUNI AIRPORT 73 94 72 93 69 / 0 - 0 - -
LA GRANGE - FAYETTE REGIONAL 73 94 71 93 70 / - - 0 - -
SAN ANTONIO INTL AIRPORT 75 95 74 95 71 / 0 0 0 - -
STINSON MUNI AIRPORT 75 96 74 96 71 / 0 - 0 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT-TERM...ALLEN
LONG-TERM...HAMPSHIRE
PUBLIC SERVICE/DATA COLLECTION...30
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 250 PM CDT THU SEP 17 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE OVER NORTHWEST ONTARIO...AND A COLD FRONT EXTENDING
SOUTHWEST ACROSS WESTERN MINNESOTA TO THE CENTRAL PLAINS. A BAND OF
SHOWERS AND STORMS ASSOCIATED WITH MID-LEVEL MOISTURE TRANSPORT AND
WEAK SHORTWAVE IMPULSES HAVE BEEN SLOWLY WEAKENING EARLY THIS
AFTERNOON AS THEY RUN INTO A MORE STABLE AIRMASS OVER CENTRAL AND
EASTERN WI. BUT SOME OF THIS RAIN SHOULD SURVIVE THE TRIP INTO
NORTHEAST WI. HOWEVER...THE RAIN AND CLOUD COVER HAVE HELD BACK
TEMPERATURES ACROSS MUCH OF WESTERN AND CENTRAL WISCONSIN...THEREBY
PREVENTING A SIGNFICANT RISE OF INSTABILITY AND REDUCING THE RISK OF
SEVERE WEATHER. THE BEST INSTABILITY RESIDES OVER MINNESOTA JUST
AHEAD OF THE FRONT WHERE STORMS ARE ANTICIPATED TO REDEVELOP LATER
THIS AFTERNOON. AS THE FRONT MOVES EAST TONIGHT...THUNDERSTORM
IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...THE COLD FRONT WILL MOVE EAST....ACROSS WESTERN AND
CENTRAL WISCONSIN THIS EVENING...AND EASTERN WISCONSIN OVERNIGHT.
AHEAD OF THE FRONT...WILL HAVE IMPRESSIVE MOISTURE TRANSPORT WITH
PWATS BETWEEN 1.5 AND 2.0 INCHES AND ELEVATED CAPES AROUND 1000
J/KG...THOUGH THINK THE ATMOSPHERE WILL GET WORKED OVER A LITTLE BY
THIS AFTERNOONS CONVECTION. SO THE SEVERE THREAT DOES NOT LOOK AS
IMPRESSIVE AS YESTERDAY GIVEN THE MARGINAL INSTABILITY...WHICH
MATCHES SPC/S ASSESSMENT. STILL THOUGH...A FEW STRONG STORMS
CAPABLE OF PRODUCING STRONG STRAIGHT LINE WINDS CANNOT BE RULED OUT
THIS EVENING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN AS CONVECTION
ROLLS IN FROM THE WEST. THE MAIN THREAT WILL BE HEAVY RAINFALL
HOWEVER. UPSTREAM OBS OVER WESTERN WISCONSIN FROM EARLIER TODAY
REPORTED UPWARDS OF 2.5 INCHES OF RAINFALL. GIVEN THE HIGH PWATS
AND SLOW MOVEMENT OF THE CONVECTION...THINK ISOLATED AMOUNTS COULD
REACH THIS AMOUNT. THE CONVECTION WILL BE WEAKENING AS IT MOVES
INTO EASTERN WISCONSIN LATE IN THE EVENING AND OVERNIGHT WHERE
RAINFALL POTENTIAL IS NOT NEARLY AS HIGH. LOW CLOUDS WILL LIKELY
LINGER BEHIND THE FRONT EVEN AS WINDS SHIFT TO THE NW. AS A
RESULT...LOWS SHOULD ONLY FALL INTO THE UPPER 50S WEST TO MID 60S
EAST.
FRIDAY...WILL LEAVE A SLIGHT CHANCE OF A SHOWER ALONG THE LAKE SHORE
AT THE START OF THE MORNING. BUT OTHERWISE...THINK THE SHOWER
ACTIVITY WILL HAVE PASSED TO THE EAST OF THE REGION BY 12Z AS THE
FRONT MOVES OVER LAKE MICHIGAN. THEN A DRY PERIOD SHOULD ENSUE
THROUGH AT LEAST MID-AFTERNOON AS NORTHWEST WINDS BRING IN DRIER
AIR. BY LATE AFTERNOON...THE RIGHT REAR QUAD OF A JETSTREAK
COMBINED WITH MID-LEVEL FGEN WILL PROMOTE A BAND OF LIGHT RAIN
LIFTING NORTHWARD TOWARDS NORTH-CENTRAL WI. BUT THE NEXT ROUND OF
PRECIP SHOULD MAINLY HOLD OFF UNTIL FRIDAY NIGHT. HIGHS COOLING OFF
ON FRIDAY INTO THE MID 60S NORTH TO MID 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 250 PM CDT THU SEP 17 2015
PCPN TRENDS AND QPF AMOUNTS FRIDAY NIGHT INTO SATURDAY MORNING
ARE THE MAIN FCST CONCERNS.
MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT ON THE FRIDAY NIGHT
SYSTEM...WITH A DEEPENING CYCLONE TRACKING NE THROUGH SOUTHERN
LAKE MICHIGAN...AS A POTENT S/W TROF MOVES THROUGH THE WSTRN
GREAT LAKES. STRONG DYNAMIC FORCING...COMBINED WITH PRECIPITABLE
WATER VALUES OF 1-1.5 INCHES...WILL LEAD TO A SIGNIFICANT RAINFALL
ACROSS ALL BUT THE NW PART OF THE CWA. HEAVY RAINFALL...WITH
AMOUNTS IN EXCESS OF AN INCH...ARE POSSIBLE IN THE FOX VALLEY/
LAKESHORE AREAS. AFTER LOOKING AT PROGS OF ELEVATED INSTABILITY...
WILL CONFINE TSTM CHANCES TO ONLY OUR SE COUNTIES. LINGERING
SHOWERS SHOULD QUICKLY EXIT NE WI EARLY SATURDAY MORNING...WITH
DECREASING CLOUDS THROUGH THE DAY. A BRIEF PERIOD OF STRONG GUSTY
NE-N WINDS IS EXPECTED OVER THE FOX VALLEY AND LAKESHORE AREAS
LATE FRIDAY NIGHT INTO SATURDAY MORNING...AND A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED.
HIGH PRESSURE WILL BRING DRY CONDITIONS FROM SATURDAY AFTERNOON
THROUGH TUESDAY. HAVE ADDED A MENTION OF PATCHY FOG TO THE
LATE SATURDAY NIGHT FCST.
THERE IS A SMALL CHANCE OF TSTMS WED-THU AS WEAK FRONTAL BOUNDARY
SAGS TOWARD NORTHERN WI. HOWEVER...THE ECMWF KEEPS A STRONG UPPER
RIDGE IN PLACE...AND HAS THE FRONT REMAINING NORTH OF THE WI/MI
BORDER. THUS...WILL ONLY HAVE SLGT CHC/CHC POPS AT THIS TIME.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1149 AM CDT THU SEP 17 2015
AN ACTIVE PERIOD OF WEATHER WILL MOVE ACROSS THE REGION
THROUGH THE END OF THE TAF PERIOD. SHOWERS AND STORMS WILL IMPACT
CENTRAL AND NORTH-CENTRAL WISCONSIN THROUGH EARLY THIS AFTERNOON.
NOT SURE HOW FAR EAST THESE STORMS WILL MAKE IT...DUE TO A MORE
STABLE AIRMASS IN THE EASTERN PART OF THE STATE. ONCE THIS FIRST
ROUND EXITS/DIMINISHES...A SECOND ROUND OF STORMS IS ANTICIPATED TO
MOVE ACROSS THE REGION LATE THIS AFTERNOON THROUGH THE EVENING.
STRONG GUSTY WINDS AND HEAVY RAIN WILL BE POSSIBLE IN ANY STORMS.
IN THE WAKE OF THESE STORMS...CIGS/VSBYS WILL LOWER TO IFR/LIFR
ALONG THE COLD FRONT. SOME IMPROVEMENT IS EXPECTED FRIDAY MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1149 AM CDT THU SEP 17 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND FRIDAY
ISSUED AT 310 AM CDT THU SEP 17 2015
FORECAST CHALLENGE CENTERS ON CONVECTION TRENDS TODAY INTO
TONIGHT AND SEVERE POTENTIAL.
AREA RADARS SHOW LEAD CONVECTION EARLY THIS MORNING NEAR THE
MINNESOTA WISCONSIN BORDER IN THE LLJ REGION...HIGHER PWATS AND
850 MB WARM AIR ADVECTION. THIS FOCUS OF CONVECTION WILL
GRADUALLY SHIFT EASTWARD TODAY BUT MAY DIMINISH FOR A PERIOD LATER
THIS MORNING. A COLD FRONT AND MID LEVEL TROUGH WITH EVEN MORE
CONVECTION WAS OVER THE NORTHERN PLAINS AND APPROACHING THE
WESTERN GREAT LAKES REGION TODAY. SHOWERS AND STORMS WILL LIKELY
BECOME MORE WIDESPREAD BY THIS AFTERNOON OVER WESTERN WISCONSIN
AND THEN TOWARD EASTERN AREAS BY THIS EVENING AS THE INITIAL
CONVECTION MERGES WITH THE WITH THE APPROACHING NORTHERN PLAINS
SYSTEM. HRRR MODEL KEEPS THE LEAD WARM SECTOR CONVECTION AND THE
FRONTAL CONVECTION A BIT MORE SEPARATE. BLEND OF MODEL RUNS
SUGGEST A FASTER DEPARTURE TOWARD FRIDAY MORNING...WITH PERHAPS A
BREAK IN PCPN FOR MUCH OF FRIDAY. PCPN BEGINS TO SPREAD BACK INTO
THE AREA FROM SOUTHWEST TO NORTHEAST AS A SURFACE WAVE TRACKS
ALONG THE FRONTAL BOUNDARY SOUTH OF THE AREA. THE NORTHERN AREAS
ARE EXPECTED TO BE OVERALL DRY ON FRIDAY. LIFT WITH THE RRQ
REGION OF THE UPPER JET NOT EXPECTED TO AFFECT THE AREA UNTIL
AFTER FRIDAY AFTERNOON.
AS FAR AS SEVERE POTENTIAL. BEST ML CAPE VALUES OCCUR THIS
AFTERNOON OVER THE WEST HALF OF THE STATE INCLUDING CENTRAL AND
NORTH CENTRAL WISCONSIN AND TOWARD EARLY EVENING OVER EASTERN
AREAS. SHEAR WILL BE ON THE INCREASE THIS AFTERNOON AND EARLY
EVENING AS MID LEVEL WINDS INCREASE AND TURN MORE WSW AS A MID
LEVEL TROUGH OF LOW PRESSURE SLIDES ALONG THE US/CANADA BORDER.
THESE LIKELY STRONGER WINDS ALOFT WILL INTERACT WITH THE SOUTH
FLOW IN THE BOUNDARY LAYER AHEAD OF THE FRONT. THIS INCREASE IN
SHEAR AND INSTABILITY WILL PRODUCE A WINDOW OF SEVERE
POTENTIAL...BUT THE STRONGER WINDS ALOFT MAY ALSO PUSH THE STORMS
EASTWARD FASTER OVERNIGHT. THE PRIMARY ISSUE WILL BE HEAVY RAIN
DUE TO HIGHER PWATS AND DAMAGING WINDS. HAIL POSSIBLE WITH ANY
SUPER STORM DEVELOPMENT IN THE SHEARED ENVIRONMENT BUT PROGGED
FORECAST SOUNDINGS INDICATE WBZ START TO FALL BELOW 10000 FEET
WELL AFTER THE FROPA AND CONVECTION. AMOUNT OF CLOUDS TODAY WILL
OBVIOUSLY AFFECT AVAILABLE INSTABILITY. SPC HAS PAINTED A SLIGHT
RISK DAY 1 TODAY OVER ALL OF CENTRAL WISCONSIN AND PARTS OF NORTH
CENTRAL AND NORTHEAST WISCONSIN.
LAST DAY OF ABOVE NORMAL TEMPERATURES THIS WEEK FOR TODAY
FOLLOWED WITH NEAR NORMAL TEMPERATURES ON FRIDAY IN THE WAKE OF
THE COLD FRONT.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 310 AM CDT THU SEP 17 2015
A WET START TO THE EXTENDED FCST AS A STRENGTHENING SFC LOW RIDES
NE THRU THE GREAT LAKES...TRAILED BY A STRONG SHORTWAVE TROF. ONCE
THIS SYSTEM CLEARS...MEAN FLOW TO BE DOMINATED BY A STRONG BAND OF
WESTERLIES RUNNING FROM THE PAC NW E-EN INTO S-CNTRL CANADA. THIS
KEEPS MOST WEATHER SYSTEMS TO OUR NW FOR THE FIRST HALF OF NEXT
WEEK WITH TEMPS HOVERING NEAR OR SLIGHTLY ABOVE NORMAL.
MODELS CONT TO BATTLE WITH THE INTERACTION OF A STRENGTHENING AREA
OF LOW PRES RIDING NE ALONG THE CDFNT AND THE APPROACH OF A STRONG
SHORTWAVE TROF/EMBEDDED SHORTWAVES FRI NGT. THE NAM REMAINS
STRONGEST/FARTHEST WEST WITH THE TRACK OF THE SFC LOW...ALTHO THE
ECMWF HAS TRENDED CLOSER TO THE NAM SOLUTION THAN 24 HOURS AGO.
THE GFS/GEM ARE WEAKER/BIT FARTHER EAST WITH THE LOW TRACK. MODELS
DO AGREE ON TWO MAIN AREAS OF PCPN WITH ONE STAYING TO OUR SOUTH
ASSOCIATED WITH STRONG ISEN LIFT AND THE OTHER MOVING THRU WI
ASSOCIATED WITH THE PRIMARY DEFORMATION ZONE. DESPITE THE MODEL
DIFFERENCES...IT APPEARS THAT THE SE HALF OF WI COULD RECEIVE A
HEALTHY RAINFALL FRI NGT WITH LOCALLY HEAVY RAINS POSSIBLE. MIN
TEMPS TO RANGE FROM THE 45-50 DEG RANGE NORTH...LWR TO MID 50S
SOUTH.
THE BIGGER FCST ISSUE MAY ACTUALLY BE WHEN TO END THE PCPN CHCS ON
SAT AS THE SLOWER NAM WOULD KEEP SHWRS GOING ALL DAY AS OPPOSED TO
THE SHWRS ENDING BY MIDDAY ON THE OTHER MODELS. HAVE CONTINUED TO
LEAN TOWARD THE MAJORITY SOLUTION MAINLY DUE TO THE PROGRESSIVE
NATURE OF THE MEAN FLOW. THEREFORE...WL KEEP POPS IN THE FCST THRU
SAT MORNING AND TREND TOWARD DECREASING CLOUDS IN THE AFTERNOON.
MAX TEMPS ARE EXPECTED TO DIP SLIGHTLY BELOW NORMAL WITH READINGS
GENERALLY IN THE LWR TO MID 60S NORTH...MID TO UPR 60S SOUTH.
HI PRES IS FCST TO MOVE EAST FROM THE CNTRL PLAINS TOWARD SRN
SECTIONS OF THE GREAT LAKES SAT NGT. MOSTLY CLEAR TO PARTLY CLOUDY
SKIES...LIGHT WINDS AND A DRIER AIR MASS WL ALLOW FOR TEMPS TO
FALL TO AROUND 40 DEGS OVER THE COLDER LOCATIONS OF THE
NORTHWOODS...AROUND 50 DEGS ALONG LAKE MI. DEPENDING ON HOW MUCH
RAIN FALLS FRI NGT/SAT MORNING...THERE COULD BE PATCHY FOG
DEVELOPING JUST ABOUT ANYWHERE OVER NE WI. THE SFC HI WL DRIFT
ACROSS THE GREAT LAKES ON SUNDAY WITH A RETURN FLOW DEVELOPING
OVER WI. IN ADDITION...MODELS SUGGEST A WEAK SHORTWAVE TROF WL
APPROACH THE GREAT LAKES SUNDAY AFTERNOON. THERE IS NOT ENUF LIFT/
FORCING/MOISTURE FOR ANY PCPN TO DEVELOP...HOWEVER WE MAY SEE SOME
CLOUDS PUSH INTO THE FCST AREA THROUGHOUT THE DAY. MAX TEMPS
SHOULD BE CLOSE TO SEASONAL NORMALS WITH PLENTY OF UPR 60S TO LWR
70S.
THIS WEAK SHORTWAVE TROF PUSHES ACROSS WI WITH ITS PASSING CLOUDS
SUNDAY NGT...THEN THE MODELS BRING RISING UPR HEIGHTS INTO THE
REGION ON MON AS SOUTHERLY WINDS TO PREVAIL. MORE SUNSHINE ON MON
WL HELP NUDGE TEMPS UP A TAD WITH READINGS RANGING FROM AROUND 70
DEGS TO THE LWR 70S. QUIET WEATHER CONDITIONS TO PREVAIL THRU TUE
WITH UPR RIDGING OVER THE WRN GREAT LAKES. MODELS DO SHOW A MODEST
CDFNT PUSHING ACROSS THE UPR MS VALLEY ON TUE...BUT BE TOO FAR
AWAY YET TO IMPACT OUR WEATHER. LOOK FOR MAX TEMPS TUE TO RANGE
FROM THE UPR 60S NEAR LAKE MI...TO THE LWR TO MID 70S OVER PARTS
OF CNTRL WI.
THE MOVEMENT OF THIS CDFNT WL ULTIMATELY DETERMINE WHEN TO PLACE
THE NEXT CHC FOR SHWRS/TSTMS INTO THE FCST. FULLY ANTICIPATE THE
MODELS TO WAFFLE ON NOT ONLY THE LOCATION OF THE FNT...BUT ALSO
HOW MUCH MOISTURE WL BE AVAILABLE WHEN THE FNT DOES ARRIVE. HAVE
FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH ONLY BRINGS A
MINIMAL POP TO N-CNTRL WI TUE NGT AND WED.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1149 AM CDT THU SEP 17 2015
AN ACTIVE PERIOD OF WEATHER WILL MOVE ACROSS THE REGION
THROUGH THE END OF THE TAF PERIOD. SHOWERS AND STORMS WILL IMPACT
CENTRAL AND NORTH-CENTRAL WISCONSIN THROUGH EARLY THIS AFTERNOON.
NOT SURE HOW FAR EAST THESE STORMS WILL MAKE IT...DUE TO A MORE
STABLE AIRMASS IN THE EASTERN PART OF THE STATE. ONCE THIS FIRST
ROUND EXITS/DIMINISHES...A SECOND ROUND OF STORMS IS ANTICIPATED TO
MOVE ACROSS THE REGION LATE THIS AFTERNOON THROUGH THE EVENING.
STRONG GUSTY WINDS AND HEAVY RAIN WILL BE POSSIBLE IN ANY STORMS.
IN THE WAKE OF THESE STORMS...CIGS/VSBYS WILL LOWER TO IFR/LIFR
ALONG THE COLD FRONT. SOME IMPROVEMENT IS EXPECTED FRIDAY MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......MPC
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1117 AM CDT THU SEP 17 2015
.UPDATE...
SCATTERED SHOWERS AND THUNDERSTORMS ARE SPREADING INTO WESTERN
WISCONSIN LATE THIS MORNING IN RESPONSE TO WEAK 925-700MB WARM AIR
ADVECTION AND STEADY MOISTURE TRANSPORT. THE LATEST 14Z HRRR MODEL
SHOWS THIS CONVECTION TRACKING EAST THROUGH SOUTHERN WI THROUGH
EARLY AFTERNOON. THIS MAY PAN OUT GRADUALLY OVER TIME... BUT THE
CONVECTION IS GETTING EATEN BY DRY AIR AS IT WORKS EAST LATE THIS
MORNING. THE INSTABILITY AND MOISTURE WILL NEED TIME TO SPREAD EAST
TODAY TO SUPPORT CONVECTION. CAPE VALUES ARE BETWEEN 500 AND 1000
J/KG IN WESTERN/SOUTH CENTRAL WI. LOW LEVEL SHEAR IS DECENT BUT BULK
SHEAR IS WEAK SO NOT EXPECTING SEVERE WITH THESE BRIEF THUNDERSTORMS.
THE MAIN EVENT WILL ARRIVE THIS EVENING AS A LINE OF CONVECTION IS
EXPECTED TO SLIDE SOUTHEAST THROUGH WI WITH A COLD FRONT. THERE IS A
SLIGHT RISK FOR SEVERE WEATHER NORTHWEST OF MADISON AND A MARGINAL
RISK ELSEWHERE.
&&
.AVIATION/18Z TAFS/...
GUSTY SOUTH WINDS AGAIN TODAY WITH GUSTS TO 20-25 KNOTS. SHOWERS AND
THUNDERSTORMS TRACKING INTO SOUTH CENTRAL WI ARE DISSIPATING AS THEY
HEAD EAST OF MADISON DUE TO DRY AIR. THE ENVIRONMENT WILL GET BETTER
FOR SUPPORTING CONVECTION FARTHER EAST LATER IN THE AFTERNOON.
EXPECT CHANCE OF SHOWERS AND THUNDERSTORMS FOR MUCH OF THE DAY.
THUNDERSTORM CHANCES INCREASE LATE THIS AFTERNOON AND EVENING WITH
THE APPROACH OF SURFACE COLD FRONT. EXPECT MVFR VSBYS IN THE
STORMS...WITH SOME STRONG WIND GUSTS AND HAIL POSSIBLE OVER MAINLY
SOUTH CENTRAL WISCONSIN LATE THIS AFTERNOON AND EVENING. WILL SEE
MVFR CIGS FRIDAY MORNING BEHIND PCPN WITH THE COLD AIR ADVECTION
BEHIND THE FRONT.
&&
.PREV DISCUSSION... /ISSUED 657 AM CDT THU SEP 17 2015/
TODAY...FORECAST CONFIDENCE MEDIUM
TWO AREAS OF CONVECTION ONGOING...THE FIRST NARROW BAND OF SHOWERS
AND THUNDERSTORMS IN ERN MN/WRN WI DRIVEN BY 850-700 MB WARM AIR
ADVECTION/MOISTURE TRANSPORT AS WELL AS CVA WITH LEAD SHORT WAVE
UNDER INCREASING 250 MB UPPER LEVEL DIVERGENCE. SECOND AREA IN THE
DAKOTAS IS WITH FORCING ASSOCIATED WITH MAIN SHORT WAVE TROUGH AND
SURFACE LOW.
UPPER LEVEL DIVERGENCE/DIFFLUENCE INCREASES THIS AFTERNOON AS IT
SHIFTS EAST AHEAD OF APPROACHING UPPER TROUGH...WITH A LEAD SHORT
WAVE REACHING LAKE MICHIGAN BY 00Z. HOWEVER 700 MB OMEGA WEAKENS
AROUND 18Z IN AREA OF 850 MB DIVERGENCE AS STRONGEST 850 MB WINDS
SPLIT... WITH ONE MAX LIFTING OFF TO THE NORTH OVER THE U.P. AND
LAKE SUPERIOR AND A SECOND MAX APPROACHES FROM MISSOURI AHEAD OF THE
MAIN TROUGH. NAM ACTUALLY SHOWING SUBSIDENCE OVER SRN WI DURING THE
AFTERNOON...WHICH EXPLAINS THE LACK OF QPF OVER THE FORECAST AREA.
WILL FOLLOW CONSENSUS BLEND WHICH BRINGS INITIAL WAA PCPN INTO SOUTH
CENTRAL WI THIS MORNING THEN LIFTS IT NORTH...WITH REDEVELOPMENT TO
THE SOUTHWEST AHEAD OF NEXT WARM...MOIST SURGE THIS AFTERNOON...
KEEPING MOST OF SOUTHEAST WISCONSIN DRY. CLOUDS...AND THIS FIRST
ROUND OF PCPN WILL KEEP HIGH TEMPS A BIT LOWER IN THE WEST THAN THAT
PAST FEW DAYS BUT WILL STILL REACH 80 MOST LOCATIONS WITH THE
WARMEST TEMPS IN THE SOUTHEAST. THOUGH 850 MB WINDS LOWER...WILL
STILL MIX UP TO AROUND 900 MB AND 20-25 KT WINDS SO IT WILL BE
BREEZY AGAIN THIS AFTERNOON.
TONIGHT...FORECAST CONFIDENCE MEDIUM.
SHOWERS AND THUNDERSTORMS WILL REDEVELOP TONIGHT AS COLD
FRONT/SURFACE TROUGH MOVES INTO THE REGION. PRECIPITABLE WATER
VALUES REACH 1.8 TO 1.9 INCHES FOR TONIGHT WITH MOISTURE TRANSPORT
RIDING IN ON 30-40KT LOW LEVEL JET AHEAD OF APPROACHING
.WITH MOST-UNSTABLE CAPE VALUES OF 1000-1300 J/KG. COULD SEE SOME
HEAVY RAIN TONIGHT...WITH SOUTH CENTRAL POSSIBLY SEEING 3/4 INCH TO
1 INCH AND THE SOUTHEAST WIDESPREAD 1/2 INCH AMOUNTS BY FRIDAY
MORNING...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. FORTUNATELY FLASH
FLOOD GUIDANCE IS HIGH WITH 1-HOURLY THRESHOLDS AROUND 2 INCHES AND
3 TO 6-HOURLY BETWEEN 2.5 AND 3 INCHES.
DEEP LAYER SHEAR DOES RISE TO 25-30 KNOTS SO POTENTIAL IS THERE FOR
ROTATING CELLS THAT COULD PRODUCE HAIL AND STRONG WIND GUSTS. SPC
HAS MOST OF SOUTH CENTRAL IN A SLIGHT RISK...MAINLY DURING PERIOD OF
MAXIMUM INSTABILITY FOR LATE THIS AFTERNOON AND EVENING...AND THE
REST OF SOUTHERN WISCONSIN IN A MARGINAL RISK FOR SEVERE.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
THE COLD FRONT IS EXPECTED TO STALL FRIDAY IN THE VICINITY OF THE
WI/IL BORDER. MEANWHILE...ANOTHER SURFACE LOW WILL TAKE AIM AT THE
AREA...MOVING THROUGH THE STALLED FRONTAL ZONE FRIDAY NIGHT AHEAD
OF A STRONG SHORTWAVE.
THINK THAT THERE MAY BE A FEW LINGERING SHOWERS/STORMS EARLY
FRIDAY FROM THE FRONTAL PASSAGE...WITH IT POSSIBLY TURNING DRY FOR
A TIME MID MORNING INTO EARLY AFTERNOON. MAY SEE A FEW MID/LATE
AFTERNOON STORMS AS INSTABILITY INCREASES...THOUGH BULK OF FORCING
NOT SET TO ARRIVE UNTIL THE EVENING AND OVERNIGHT HOURS.
MODELS STILL STRUGGLING WITH THE PATH/SPEED OF THE STRONG SURFACE
LOW FRIDAY NIGHT. THE GFS HAS IT OVER THE SOUTHERN TIP OF LAKE
MICHIGAN AT DAYBREAK SATURDAY...WITH THE NAM PUTTING THE CENTER OF
THE LOW OVER THE WESTERN FORECAST AREA. MEANWHILE...THE ECMWF AND
CANADIAN HAVE THE LOW OVER EASTERN LOWER MICHIGAN. FOR NOW...STUCK
CLOSE TO THE ECMWF/CANADIAN SOLUTIONS...WHICH HAVE BEEN PRETTY
CONSISTENT THE LAST COUPLE DAYS. EITHER WAY...LOOKS LIKE A WET
EVENING AND NIGHT WITH WIDESPREAD RAINFALL EXPECTED. BEST CHANCE
FOR CONVECTION IN THE SOUTHEAST FORECAST AREA...AS THE WARM SECTOR
AND BETTER INSTABILITY TRY TO SNEAK IN. MODELS STILL GENERALLY
PAINTING OUT 0.5 TO 1.O INCH OF RAIN OVERNIGHT.
HAVE POPS LINGERING INTO SATURDAY MORNING...MAINLY IGNORING NAM
FOR NOW...WHICH WOULD LINGER RAIN MUCH OF THE DAY. SHOULD BE DRY
BY LATE MORNING OR EARLY AFTERNOON AS HIGH PRESSURE BEGINS TO
BUILD IN FROM THE WEST.
THOUGH THE SURFACE FRONT IS PROGGED TO BE MAINLY SOUTH OF MUCH OF
THE FORECAST AREA BY LATE MORNING FRIDAY...MODELS STILL SHOWING
PRETTY MILD TEMPS AT 925 MB. KEPT HIGHS CLOSER TO MODEL 2M TEMPS
THOUGH...AS IT WILL PROBABLY BE HARD TO TAP THOSE WARMER TEMPS
GIVEN THE POSITION OF THE FRONT...ALONG WITH CLOUDS AND PRECIP
CHANCES. WILL BE COOLER THEN SATURDAY IN THE WAKE OF THE DEPARTING
LOW.
SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...HIGH
MODELS IN PRETTY GOOD AGREEMENT THAT HIGH PRESSURE WILL BE OVERHEAD
FOR SUNDAY THROUGH WEDNESDAY. LOOKS LIKE PLENTY OF SUNSHINE WITH
HIGH TEMPS WARMING BACK TO AROUND OR A LITTLE ABOVE AVERAGE
VALUES FOR THE LAST COUPLE DAYS OF SUMMER.
AVIATION/12Z TAFS...
NARROW BAND OF SHOWERS AND THUNDERSTORMS OVER FAR WESTERN
WISCONSIN EARLY THIS MORNING IS DIMINISHING AS LOW-LEVEL JET
MOVES TO THE NORTH. WILL WATCH SHOWERS AND STORMS IN IOWA
APPROACHING WITH A WEAK WAVE...BUT EXPECT VFR CONDITIONS THROUGH
THE MORNING AND EARLY AFTERNOON. GUSTY SOUTH WINDS AGAIN TODAY
WITH GUSTS TO 20-25 KNOTS.
SHOWER AND STORM CHANCES INCREASE LATE THIS AFTERNOON AND EVENING
WITH THE APPROACH OF SURFACE COLD FRONT. EXPECT MVFR VSBYS IN THE
STORMS...WITH SOME STRONG WIND GUSTS AND HAIL POSSIBLE OVER MAINLY SOUTH
CENTRAL WISCONSIN LATE THIS AFTERNOON AND EVENING. WILL SEE MVFR
CIGS FRIDAY MORNING BEHIND PCPN WITH THE COLD AIR ADVECTION BEHIND
THE FRONT.
MARINE...
SOUTH WINDS AGAIN INCREASE TO 10 TO 20 KNOTS BY LATE
MORNING....WITH GUSTS TO 25 KNOTS FREQUENT ENOUGH FROM PORT
WASHINGTON NORTH TO KEEP SMALL CRAFT ADVISORY AS IS. WINDS AND
WAVES MARGINAL SOUTH OF PORT WASHINGTON. LOOKING FOR THUNDERSTORMS
TO REACH THE NEARSHORE WATERS BY EARLY EVENING AHEAD OF A COLD
FRONT. SOME STORMS COULD PRODUCE STRONG WIND GUSTS AND HAIL.
BEACHES...
WITH SOUTH WINDS OF 15 TO 25 KNOTS AND WAVES OF 3 TO 5 FEET HAVE
ISSUED A BEACH HAZARD STATEMENT FOR THE BEACHES OF SHEBOYGAN COUNTY
TO LINE UP WITH THE SMALL CRAFT ADVISORY. HAZARDOUS CONDITIONS WILL
LINGER INTO THE EVENING BEFORE WINDS AND WAVES LOWER. A MODERATE
SWIM RISK WILL EXIST AT THE LAKE MICHIGAN BEACHES FROM OZAUKEE
COUNTY SOUTH THROUGH KENOSHA COUNTY FROM MID MORNING THROUGH EARLY
EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR WIZ052.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...DDV