Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/06/13
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
1005 AM PDT WED SEP 4 2013
.SYNOPSIS...
HOT AND MUGGY CONDITIONS WILL REDEVELOP OVER SOUTHERN CALIFORNIA FOR
THE END OF THE WORK WEEK...AS HIGH PRESSURE STRENGTHENS INTO THE
REGION. A SHALLOW MARINE LAYER WILL HELP MODERATE TEMPERATURES
ALONG THE COAST THOUGH...WHILE INLAND AREAS RANGE 5 TO 10 DEGREES
ABOVE NORMAL. SUBTROPICAL MOISTURE WILL ALSO CONTINUE TO SPREAD
INTO THE SOUTHLAND THROUGH THE WEEK...WITH THE THREAT OF AFTERNOON
SHOWERS AND THUNDERSTORMS CONTINUING IN THE MOUNTAINS AND DESERTS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
TODAY...
MADE SOME CHANGES TO THE GRIDS AND SENT UPDATED FORECASTS TO SHOW
MORE AREAL COVERAGE OF THUNDERSTORMS...A LITTLE FURTHER WEST OF
MOUNTAINS DUE TO SHIFT IN TRANSPORT WINDS TO THE SOUTHEAST AND
APPROACH OF OUTFLOW BOUNDARY FROM MASSIVE NOT SO MESOSCALE
CONVECTIVE COMPLEX THAT OCCURRED OVER SONORA...SINALOA...GULF OF
CALIFORNIA...AND BAJA CALIFORNIA...AND HAS NOW TURNED THE CORNER AND
HEADING NORTHWEST. HAD A LINE OF ALTOCUMULUS CASTELLANUS ALONG THE
PENINSULAR RIDGE LINE AT SUNRISE...AT 0935 PDT COULD VISUALLY SEE
THE OVERSHOOTING TOPS IN REFORMED COMPLEX MOVING INTO IMPERIAL
COUNTY. THE 04/15Z HRRR MODEL HAS FINALLY PICKED UP ON THIS...NONE
OF THE OTHER MODELS DID. WORSE YET IT SHOWS THE THUNDERSTORMS
DEVELOPING ALONG THE ELSINORE CONVERGENCE ZONE THIS AFTERNOON...SO
MAY NEED ANOTHER UPDATE TO SPREAD THE THUNDERSTORMS EVEN FURTHER
WEST. THE GOOD NEWS...IF ANY ...IN ALL THIS IS THE AIR MASS IN THE
-10C TO -20C LAYER IS DRIER THAN YESTERDAY AND THE OVERALL COLUMN
LOOKS DRIER ALTHOUGH THE PRECIPITABLE WATER AND THE CAPE VALUES WERE
ESSENTIALLY THE SAME...SO AT LEAST INITIALLY THROUGH EARLY AFTERNOON
THE ICE/HAIL PRODUCTION SHOULD BE LESS...AND THE WIDESPREAD HEAVY
RAIN LEADING TO FLASH FLOODING WOULD BE LESS...AGAIN ASSUMING NO AIR
MASS CHANGE THIS AFTERNOON...WHICH IS LOOKING LIKE A SHAKY
ASSUMPTION THIS MORNING.
OTHERWISE THE FORECAST LOOKS GOOD ESPECIALLY WITH THE WARMER
TEMPERATURES TODAY AND AGAIN THURSDAY. SO FAR TEMPS ARE FORECAST
JUST BELOW HEAT ADVISORY CRITERIA.
EXCERPTS FROM THE EARLY MORNING DISCUSSION FOLLOW...
WATER VAPOR IMAGERY CONTINUES TO SHOW AN ELONGATED TROUGH OF LOW
PRESSURE ALONG THE WEST COAST AND HIGH PRESSURE CENTERED OVER
COLORADO. AT THIS TIME...SOUTHERN CALIFORNIA REMAINS UNDER THE
INFLUENCE OF THIS HIGH PRESSURE SYSTEM...WHICH WILL GRADUALLY
STRENGTHEN OVER THE NEXT COUPLE OF DAYS. AS A RESULT...HOT
CONDITIONS WILL DEVELOP ACROSS THE INLAND AREAS...WITH TEMPERATURES
RANGING 5 TO 10 DEGREES ABOVE NORMAL. A FEW OF THE WARMEST SPOTS
MAY BE EVEN HOTTER...TOPPING OUT AT 15 DEGREES ABOVE NORMAL. THAT
BEING SAID...IT DOES NOT APPEAR THAT ANY RECORDS WILL BE BROKEN AT
THIS TIME...SO WILL JUST HIGHLIGHT THE HEAT WITH A SPECIAL WEATHER
STATEMENT. THE OTHER MAIN CONCERN FOR TODAY WILL BE WITH THE THREAT
OF AFTERNOON SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS AND
DESERTS...
THE OVERALL PATTER WILL CHANGE OVER THE NEXT COUPLE OF DAYS...SO HOT
CONDITIONS WILL LIKELY PREVAIL ACROSS THE INLAND AREAS...WITH
ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS POSSIBLE IN THE
MOUNTAINS AND DESERTS. THE TROUGH WILL THEN MOVE INLAND ACROSS THE
THE PACIFIC NORTHWEST LATE FRIDAY AND INTO THE WEEKEND. THIS WILL
BRING SOME RELIEF TO THE HOT WEATHER...AS A GRADUAL COOLING TREND
DEVELOPS. HOWEVER...THE MODELS CONTINUE TO INDICATE THE POTENTIAL
FOR AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS AND
DESERTS. THE MODELS START TO DEVIATE A BIT FOR EARLY NEXT
WEEK...BUT IT APPEARS THAT AN UPPER LEVEL DISTURBANCE WILL DEVELOP
OFF OR ALONG THE SOUTHERN CALIFORNIA COAST. THE PLACEMENT OF THIS
DISTURBANCE WILL ULTIMATELY DICTATE OUR WEATHER...BUT FOR NOW...WILL
CONTINUE WITH THE THREAT OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER
THE MOUNTAINS AND DESERTS AND MORE SEASONAL TYPE TEMPERATURES
PREVAILING.
&&
.AVIATION...
041515Z...COAST/VALLEYS...FEW-SCT CLDS AOA 9000 FT MSL DURING THE
1900-05/0300 UTC TIME-PERIOD. ALSO...SLIGHT CHANCE OF FOG REACHING
KSAN...KCRQ...AND/OR KSNA DURING THE 05/1100-1500 UTC
TIME-FRAME...BUT CONFIDENCE IS LOW. OTHERWISE...MOSTLY UNRESTRICTED
VIS/CIGS THROUGH THURSDAY MORNING.
MTNS/DESERTS...SCATTERED THUNDERSTORMS DURING THE 1800-05/0300 UTC
TIME-PERIOD WITH BASES 7000-10000 FT MSL AND CB TOPS TO 45000 FT
MSL...RESULTING IN LOCAL VIS AOB 2SM IN HEAVY RAIN...SMALL
HAIL...AND POSSIBLE STRONG UP/DOWNDRAFTS. OTHERWISE...UNRESTRICTED
VIS THROUGH THURSDAY MORNING.
&&
.FIRE WEATHER...
NEAR RECORD HIGH TEMPERATURES BUT ENOUGH MOISTURE IN AIR TO KEEP MIN
RELATIVE HUMIDITY VALUES AT OR ABOVE 25 PERCENT. MARINE LAYER DEPTH
WILL GENERALLY STAY NEAR OR BELOW 700 FEET. THREAT OF DRY LIGHTING
WEST OF MOUNTAINS THIS AFTERNOON...ALTHOUGH THAT MAY BE JUST A
TEMPORARY TRANSITION TO WET THUNDERSTORMS DURING THE LATER
AFTERNOON. ISSUED UPDATE TO FIRE WEATHER PLANNING FORECAST TO SHOW
MORE THUNDERSTORM COVERAGE...HIGHER LAL...THREAT OF HEAVY RAIN
OVER/NEAR MOUNTAINS AND DESERTS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC/FIRE WEATHER...JT/BALFOUR
AVIATION/MARINE...HARRISON/PIERCE
SHORT TERM WARNINGS...JJT/JT
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
454 PM CDT WED SEP 4 2013
.DISCUSSION...
300 PM CDT
THE FORECAST CHALLENGES ARE MAINLY TEMPERATURES AS SUMMER LOOKS TO
WIN OUT OVER AUTUMN IN THE EARLY GOING OF SEPTEMBER.
SYNOPSIS...IMPRESSIVELY DEEP UPPER TROUGH OVER EASTERN CANADA IS
BEING REINFORCED THIS AFTERNOON WITH A VIGOROUS JET DIVING INTO
THE UPPER GREAT LAKES. AS A GEE-WHIZ AND A SIGN OF THE CHANGE IN
SEASONS...NOT HERE YET BUT UP NORTH...850MB TEMPS AT CWZC ON THE
SOUTHERN END OF JAMES BAY DROPPED FROM +11C LAST NIGHT TO -5C THIS
MORNING UNDER THAT UPPER TROUGH. AN ASSOCIATED SURFACE COLD FRONT
IS DRAPED FROM LAKE ONTARIO THROUGH CENTRAL WI INTO SOUTHERN MN.
THIS FRONT HAS BEEN MOVING SLOWLY BUT CONSISTENTLY SOUTHWARD TODAY
WITH A RIBBON OF STRATUS/STRATOCU BEHIND IT. ALSO SEEN UPSTREAM IS A
SHEARING OUT SHORTWAVE ACROSS NW MN WHICH WILL CONTINUE TO MOVE
SOUTHEASTWARD.
TONIGHT...GIVEN THE COLD FRONT ORIENTATION AND THE LOSS OF MIXING
OF WESTERLY WINDS...EXPECT THE SURFACE COLD FRONT TO PROGRESS
QUICKER DOWN THE LAKE THIS EVENING...REACHING CHICAGO BY JUST
AFTER SUNDOWN OR SO. THIS WILL MEAN A TURN TO NORTHEAST WINDS AND
A DROP IN TEMPERATURE BY SEVERAL DEGREES LIKELY IN JUST A COUPLE
HOURS. READINGS SHOULD THEN STABILIZE NEAR THE LAKE GIVEN THE
STILL MILD WATER TEMPERATURES. THE NAM AND RAP SOUNDINGS ALONG
WITH COLD AIR ADVECTION AND RH FIELDS SUPPORT AT LEAST PATCHY
STRATUS MAKING IT DOWN INTO THE AREA NOT LONG BEHIND THE FRONT.
LOW-LEVEL THERMAL PROFILES ALSO HOVER AROUND LAPSE RATES
SUPPORTIVE OF LAKE-INDUCED CLOUDS. WITH THESE FORECASTS MESHING
WITH OBSERVATIONAL TRENDS UPSTREAM...HAVE BUMPED UP SKY COVER
LATER THIS EVE INTO OVERNIGHT. ALSO...AFOREMENTIONED SHEARING
SHORT WAVE OVER NW MN WILL RIDE A TIGHT 600-800MB THERMAL GRADIENT
INTO NW/NC IL BY EARLY OVERNIGHT. NAM FORECAST SOUNDINGS OVER RFD
WOULD CONTINUE TO SUPPORT A CHANCE FOR SOME SPRINKLES LATE AS THE
WAVE OVERRIDES SOME OF THE LOWER LEVEL MOISTURE. SO CONTINUE THAT
IN THE FORECAST BUT HAVE JUST BACKED UP IN TIME. WHILE A COLD
FRONT IS EASING THROUGH...TEMPERATURES WILL END UP SEVERAL DEGREES
WARMER THAN LAST NIGHT WITH MORE OF A WIND COMPONENT AND
INCREASING CLOUD COVER ACTING AS INSULATION.
THURSDAY THROUGH SATURDAY...FAIRLY QUIET WEATHER INTO FRIDAY
CONTINUES TO BE THE TREND IN THE WEATHER PATTERN. NORTHEAST WINDS
WILL CONTINUE INTO THU WITH TEMPERATURES IN THE 70S ACROSS AREAS
NORTH OF I-80. WARM AIR ADVECTION BEGINS FRIDAY AS THE HIGHS
SHIFTS EAST. THE 04.00 EC WAS FAIRLY SHARP WITH THIS ALOFT AND
HAVING A COINCIDENT SHORT WAVE WITH OUTPUT QPF. ITS MORE CURRENT
RUN IS MORE IN LINE WITH OTHER GUIDANCE...THAT IS DRIER AND
CONTINUE AS SUCH IN THE FORECAST. NEXT SHORT WAVE DROPS OVER THE
GREAT LAKES WITH ASSOCIATED WEAK SURFACE COLD FRONT OOZING
SOUTHWARD ON SAT. BEST LAPSE RATES AND MOISTURE ARE REALLY
CONFINED TO THE FRONT...SO DO NOT INTRODUCE SHOWER CHANCES UNTIL
SAT AFTERNOON AND AT THAT LOW AT THIS TIME. TEMPS RIGHT NOW LOOK
TO BE IN THE MID 80S FOR SAT GIVEN LOCAL CLIMATOLOGY...AND GIVEN
LOW-LEVEL THERMAL VALUES WHAT THEY WERE TODAY BUT WITH EVEN MORE
SW ADVECTION.
MTF
EXTENDED FORECAST SAT NIGHT-WED...WEAK COLD FRONT CONTINUES TO DROP
SOUTH THROUGH THE AREA SATURDAY EVENING INTO SUNDAY. WILL KEEP LOW
POPS FOR SATURDAY NIGHT...AND FOR THE SOUTHERN PART OF THE FORECAST
AREA SUNDAY. HIGH PRESSURE MOVES ACROSS THE LAKES SUNDAY WITH
NORTHEAST SURFACE WINDS. THIS SHOULD BRING DRY AND A LITTLE COOLER
WEATHER...ESPECIALLY NEAR THE LAKE. SUNDAY NIGHT INTO MONDAY THE
UPPER RIDGE AXIS SHIFTS EAST TOWARD THE GREAT LAKES AND THE SURFACE
HIGH SHIFTS EAST BRINGING A RETURN TO SOUTHERLY FLOW AND WARMER
WEATHER. GUIDANCE PRODUCING SLIGHT CHANCE POPS MOST PERIODS DAYS 4
THOUGH 7 BUT DON`T SEE ANY REAL FOCUS FOR THUNDERSTORMS SUNDAY NIGHT
THROUGH MONDAY NIGHT OR TUESDAY. AS UPPER RIDGE AXIS PUSHES EAST
THROUGH THE GREAT LAKES THE HEAT DOMES SPREADS EAST. TUESDAY LOOKS
ESPECIALLY WARM WITH GFS 925 MB TEMPS 26-28C AND ECMWF EVEN A BIT
WARMER WITH STRONG WSW FLOW. LOOKING AT CIPS ANALOGS...SIMILAR
PATTERNS IN LATE AUGUST AND SEPTEMBER YIELDED SURFACE TEMPS MOSTLY
IN THE LOWER 90S. HAVE BUMPED UP MAX TEMPS OVER GUIDANCE FOR
TUESDAY. NOT GOING TO GO WILD WITH TEMPS 6 DAYS OUT...BUT WILL
CONTINUE TO MONITOR. COULD SEE NEAR RECORD HIGHS TUESDAY IF MODELS
PAN OUT AND WE GET ENOUGH SUNSHINE. UPPER TROF MOVES ACROSS THE
UPPER LAKES AND TRAILING SURFACE COLD FRONT APPROACHES THE FORECAST
AREA TUESDAY NIGHT INTO WEDNESDAY FOR THE BEST CHANCE OF
THUNDERSTORMS IN THE EXTENDED PERIOD.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* TIMING OF WINDS QUICKLY SHIFTING TO NORTHEAST FOLLOWING THE
FROPA THIS EVENING.
* SMALL CHANCE FOR A SHORT PERIOD OF MVFR CIGS FOLLOWING FROPA.
KREIN
//DISCUSSION...UPDATED 18Z...
THE MAIN FORECAST CONCERNS WILL BE THE TIMING OF THE COLD FRONTAL
PASSAGE THIS EVENING...AND THE ASSOCIATED RAPID WIND SHIFT OUT OF
THE NORTHEAST...AS WELL AS THE THREAT FOR A PERIOD OF MVFR CIGS
OVERNIGHT.
WINDS ARE EXPECTED TO REMAIN OUT OF THE WEST AROUND 10 KT THROUGH
THE AFTERNOON. HOWEVER...A COLD FRONT..CURRENTLY DROPPING SOUTHWARD
THROUGH CENTRAL WISCONSIN AND LAKE MICHIGAN...WILL PRODUCE A
SIGNIFICANT WIND SHIFT OUT OF THE NORTHEAST BY EARLY THIS EVENING AS
IT MOVES ACROSS THE TERMINALS. TIMING OF THIS FRONT APPEARS THAT IT
MAY BE A BIT SLOWER THAN PREVIOUSLY THOUGHT. THEREFORE...I PUSHED
OFF THE TIMING AROUND AN HOUR...WITH A PASSAGE AROUND OR SHORTLY
AFTER 02 UTC AT ORD...AND AFTER 03 UTC AT MDW. ONCE THIS FRONT
PASSES...EXPECT A RAPID WIND SHIFT OUT OF THE NORTHEAST. THESE WINDS
WILL LIKELY INCREASE SOME IN MAGNITUDE...WITH SOME GUSTS UP IN THE
UPPER TEENS...LATER TONIGHT INTO THURSDAY.
THE OTHER CONCERN IS FOR A PERIOD OF LOWER CLOUDS IN THE 1-2,000
FOOT RANGE LATER TONIGHT AFTER 04 UTC. CURRENT SATELLITE IMAGERY
INDICATES A GOOD AMOUNT OF MVFR CLOUD COVER IN THE WAKE OF THE COLD
FRONT ACROSS NORTHERN LAKE MICHIGAN AND NORTHERN WISCONSIN EARLY
THIS AFTERNOON. THIS CLOUD COVER MAY IMPACT NORTHERN ILLINOIS
OVERNIGHT TONIGHT BEFORE IMPROVING BY EARLY THURSDAY AS COLD AIR
MOVES IN ACROSS THE AREA. FOR THIS REASON...I HAVE OPTED TO ADD SOME
MVFR CIGS TO THE 18 UTC TAFS OVERNIGHT TONIGHT. CONFIDENCE IS LOW TO
MODERATE IN THIS OCCURRING.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE OF TIMING OF FROPA THIS EVENING...WITH MEDIUM
TO HIGH CONFIDENCE IN WIND TRENDS.
* MEDIUM TO HIGH CONFIDENCE IN CEILING TRENDS...WITH LOW
CONFIDENCE IN THE POTENTIAL FOR A SHORT PERIOD OF MVFR CEILINGS
FOLLOWING THE FROPA.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SLIGHT CHANCE OF TSRA LATE...OTHERWISE VFR.
SUNDAY...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
MONDAY...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
229 PM CDT
A COLD FRONT IS STARTING TO MAKE ITS WAY DOWN LAKE MICHIGAN THIS
AFTERNOON WITH A PUSH OF NORTH-NORTHEASTERLY FLOW BEHIND THE FRONT
INCREASING THE WINDS INTO THE 15 TO 20 KT RANGE WITH OCCASIONAL
GUSTS TO 25 KT POSSIBLE. THE FRONT SHOULD CLEAR THE SOUTH END OF THE
LAKE AROUND MIDNIGHT TONIGHT. WITH A DECENT FETCH DOWN THE
LAKE...WAVES ARE EXPECTED TO BUILD INTO THE 3 TO 6 FT RANGE AT THE
SOUTH END OF THE LAKE PROMPTING A SMALL CRAFT ADVISORY FOR MAINLY
THE ILLINOIS NEARSHORE WATERS LATE THIS EVENING AND OVERNIGHT.
THESE CONDITIONS SHOULD SUBSIDE BACK BELOW CRITERIA THURSDAY
AFTERNOON AS HIGH PRESSURE PASSES OVER THE LAKE. AS THE HIGH
SHIFTS OVER THE EASTERN LAKES FRIDAY...SOUTHERLY FLOW INCREASES
AGAIN ACROSS THE LAKE. ANOTHER FRONT IS EXPECTED TO SAG SOUTH
ACROSS THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...4 AM THURSDAY TO 5 AM
FRIDAY.
IN...BEACH HAZARDS STATEMENT...INZ001...4 AM THURSDAY TO 5 AM FRIDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...4 AM
THURSDAY TO 3 PM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CDT WED SEP 4 2013
.DISCUSSION...
300 PM CDT
THE FORECAST CHALLENGES ARE MAINLY TEMPERATURES AS SUMMER LOOKS TO
WIN OUT OVER AUTUMN IN THE EARLY GOING OF SEPTEMBER.
SYNOPSIS...IMPRESSIVELY DEEP UPPER TROUGH OVER EASTERN CANADA IS
BEING REINFORCED THIS AFTERNOON WITH A VIGOROUS JET DIVING INTO
THE UPPER GREAT LAKES. AS A GEE-WHIZ AND A SIGN OF THE CHANGE IN
SEASONS...NOT HERE YET BUT UP NORTH...850MB TEMPS AT CWZC ON THE
SOUTHERN END OF JAMES BAY DROPPED FROM +11C LAST NIGHT TO -5C THIS
MORNING UNDER THAT UPPER TROUGH. AN ASSOCIATED SURFACE COLD FRONT
IS DRAPED FROM LAKE ONTARIO THROUGH CENTRAL WI INTO SOUTHERN MN.
THIS FRONT HAS BEEN MOVING SLOWLY BUT CONSISTENTLY SOUTHWARD TODAY
WITH A RIBBON OF STRATUS/STRATOCU BEHIND IT. ALSO SEEN UPSTREAM IS A
SHEARING OUT SHORTWAVE ACROSS NW MN WHICH WILL CONTINUE TO MOVE
SOUTHEASTWARD.
TONIGHT...GIVEN THE COLD FRONT ORIENTATION AND THE LOSS OF MIXING
OF WESTERLY WINDS...EXPECT THE SURFACE COLD FRONT TO PROGRESS
QUICKER DOWN THE LAKE THIS EVENING...REACHING CHICAGO BY JUST
AFTER SUNDOWN OR SO. THIS WILL MEAN A TURN TO NORTHEAST WINDS AND
A DROP IN TEMPERATURE BY SEVERAL DEGREES LIKELY IN JUST A COUPLE
HOURS. READINGS SHOULD THEN STABILIZE NEAR THE LAKE GIVEN THE
STILL MILD WATER TEMPERATURES. THE NAM AND RAP SOUNDINGS ALONG
WITH COLD AIR ADVECTION AND RH FIELDS SUPPORT AT LEAST PATCHY
STRATUS MAKING IT DOWN INTO THE AREA NOT LONG BEHIND THE FRONT.
LOW-LEVEL THERMAL PROFILES ALSO HOVER AROUND LAPSE RATES
SUPPORTIVE OF LAKE-INDUCED CLOUDS. WITH THESE FORECASTS MESHING
WITH OBSERVATIONAL TRENDS UPSTREAM...HAVE BUMPED UP SKY COVER
LATER THIS EVE INTO OVERNIGHT. ALSO...AFOREMENTIONED SHEARING
SHORT WAVE OVER NW MN WILL RIDE A TIGHT 600-800MB THERMAL GRADIENT
INTO NW/NC IL BY EARLY OVERNIGHT. NAM FORECAST SOUNDINGS OVER RFD
WOULD CONTINUE TO SUPPORT A CHANCE FOR SOME SPRINKLES LATE AS THE
WAVE OVERRIDES SOME OF THE LOWER LEVEL MOISTURE. SO CONTINUE THAT
IN THE FORECAST BUT HAVE JUST BACKED UP IN TIME. WHILE A COLD
FRONT IS EASING THROUGH...TEMPERATURES WILL END UP SEVERAL DEGREES
WARMER THAN LAST NIGHT WITH MORE OF A WIND COMPONENT AND
INCREASING CLOUD COVER ACTING AS INSULATION.
THURSDAY THROUGH SATURDAY...FAIRLY QUIET WEATHER INTO FRIDAY
CONTINUES TO BE THE TREND IN THE WEATHER PATTERN. NORTHEAST WINDS
WILL CONTINUE INTO THU WITH TEMPERATURES IN THE 70S ACROSS AREAS
NORTH OF I-80. WARM AIR ADVECTION BEGINS FRIDAY AS THE HIGHS
SHIFTS EAST. THE 04.00 EC WAS FAIRLY SHARP WITH THIS ALOFT AND
HAVING A COINCIDENT SHORT WAVE WITH OUTPUT QPF. ITS MORE CURRENT
RUN IS MORE IN LINE WITH OTHER GUIDANCE...THAT IS DRIER AND
CONTINUE AS SUCH IN THE FORECAST. NEXT SHORT WAVE DROPS OVER THE
GREAT LAKES WITH ASSOCIATED WEAK SURFACE COLD FRONT OOZING
SOUTHWARD ON SAT. BEST LAPSE RATES AND MOISTURE ARE REALLY
CONFINED TO THE FRONT...SO DO NOT INTRODUCE SHOWER CHANCES UNTIL
SAT AFTERNOON AND AT THAT LOW AT THIS TIME. TEMPS RIGHT NOW LOOK
TO BE IN THE MID 80S FOR SAT GIVEN LOCAL CLIMATOLOGY...AND GIVEN
LOW-LEVEL THERMAL VALUES WHAT THEY WERE TODAY BUT WITH EVEN MORE
SW ADVECTION.
MTF
EXTENDED FORECAST SAT NIGHT-WED...WEAK COLD FRONT CONTINUES TO DROP
SOUTH THROUGH THE AREA SATURDAY EVENING INTO SUNDAY. WILL KEEP LOW
POPS FOR SATURDAY NIGHT...AND FOR THE SOUTHERN PART OF THE FORECAST
AREA SUNDAY. HIGH PRESSURE MOVES ACROSS THE LAKES SUNDAY WITH
NORTHEAST SURFACE WINDS. THIS SHOULD BRING DRY AND A LITTLE COOLER
WEATHER...ESPECIALLY NEAR THE LAKE. SUNDAY NIGHT INTO MONDAY THE
UPPER RIDGE AXIS SHIFTS EAST TOWARD THE GREAT LAKES AND THE SURFACE
HIGH SHIFTS EAST BRINGING A RETURN TO SOUTHERLY FLOW AND WARMER
WEATHER. GUIDANCE PRODUCING SLIGHT CHANCE POPS MOST PERIODS DAYS 4
THOUGH 7 BUT DON`T SEE ANY REAL FOCUS FOR THUNDERSTORMS SUNDAY NIGHT
THROUGH MONDAY NIGHT OR TUESDAY. AS UPPER RIDGE AXIS PUSHES EAST
THROUGH THE GREAT LAKES THE HEAT DOMES SPREADS EAST. TUESDAY LOOKS
ESPECIALLY WARM WITH GFS 925 MB TEMPS 26-28C AND ECMWF EVEN A BIT
WARMER WITH STRONG WSW FLOW. LOOKING AT CIPS ANALOGS...SIMILAR
PATTERNS IN LATE AUGUST AND SEPTEMBER YIELDED SURFACE TEMPS MOSTLY
IN THE LOWER 90S. HAVE BUMPED UP MAX TEMPS OVER GUIDANCE FOR
TUESDAY. NOT GOING TO GO WILD WITH TEMPS 6 DAYS OUT...BUT WILL
CONTINUE TO MONITOR. COULD SEE NEAR RECORD HIGHS TUESDAY IF MODELS
PAN OUT AND WE GET ENOUGH SUNSHINE. UPPER TROF MOVES ACROSS THE
UPPER LAKES AND TRAILING SURFACE COLD FRONT APPROACHES THE FORECAST
AREA TUESDAY NIGHT INTO WEDNESDAY FOR THE BEST CHANCE OF
THUNDERSTORMS IN THE EXTENDED PERIOD.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WINDS RAPIDLY TURNING NORTHEAST WITH FROPA THIS EVENING.
* MVFR CEILINGS POSSIBLY DEVELOPING ACROSS THE TERMINALS AFTER 04
UTC TONIGHT.
KJB
//DISCUSSION...UPDATED 18Z...
THE MAIN FORECAST CONCERNS WILL BE THE TIMING OF THE COLD FRONTAL
PASSAGE THIS EVENING...AND THE ASSOCIATED RAPID WIND SHIFT OUT OF
THE NORTHEAST...AS WELL AS THE THREAT FOR A PERIOD OF MVFR CIGS
OVERNIGHT.
WINDS ARE EXPECTED TO REMAIN OUT OF THE WEST AROUND 10 KT THROUGH
THE AFTERNOON. HOWEVER...A COLD FRONT..CURRENTLY DROPPING SOUTHWARD
THROUGH CENTRAL WISCONSIN AND LAKE MICHIGAN...WILL PRODUCE A
SIGNIFICANT WIND SHIFT OUT OF THE NORTHEAST BY EARLY THIS EVENING AS
IT MOVES ACROSS THE TERMINALS. TIMING OF THIS FRONT APPEARS THAT IT
MAY BE A BIT SLOWER THAN PREVIOUSLY THOUGHT. THEREFORE...I PUSHED
OFF THE TIMING AROUND AN HOUR...WITH A PASSAGE AROUND OR SHORTLY
AFTER 02 UTC AT ORD...AND AFTER 03 UTC AT MDW. ONCE THIS FRONT
PASSES...EXPECT A RAPID WIND SHIFT OUT OF THE NORTHEAST. THESE WINDS
WILL LIKELY INCREASE SOME IN MAGNITUDE...WITH SOME GUSTS UP IN THE
UPPER TEENS...LATER TONIGHT INTO THURSDAY.
THE OTHER CONCERN IS FOR A PERIOD OF LOWER CLOUDS IN THE 1-2,000
FOOT RANGE LATER TONIGHT AFTER 04 UTC. CURRENT SATELLITE IMAGERY
INDICATES A GOOD AMOUNT OF MVFR CLOUD COVER IN THE WAKE OF THE COLD
FRONT ACROSS NORTHERN LAKE MICHIGAN AND NORTHERN WISCONSIN EARLY
THIS AFTERNOON. THIS CLOUD COVER MAY IMPACT NORTHERN ILLINOIS
OVERNIGHT TONIGHT BEFORE IMPROVING BY EARLY THURSDAY AS COLD AIR
MOVES IN ACROSS THE AREA. FOR THIS REASON...I HAVE OPTED TO ADD SOME
MVFR CIGS TO THE 18 UTC TAFS OVERNIGHT TONIGHT. CONFIDENCE IS LOW TO
MODERATE IN THIS OCCURRING.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION TODAY...WITH MEDIUM
CONFIDENCE OF TIMING AND TRENDS OF FROPA THIS EVENING.
* MEDIUM CONFIDENCE WITH CEILING TRENDS LATER TONIGHT...WITH LOW-
MEDIUM CONFIDENCE IN THE POTENTIAL FOR FOR A PERIOD OF MVFR
CEILINGS AFTER 04 UTC.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SLIGHT CHANCE OF TSRA LATE...OTHERWISE VFR.
SUNDAY...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
MONDAY...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
229 PM CDT
A COLD FRONT IS STARTING TO MAKE ITS WAY DOWN LAKE MICHIGAN THIS
AFTERNOON WITH A PUSH OF NORTH-NORTHEASTERLY FLOW BEHIND THE FRONT
INCREASING THE WINDS INTO THE 15 TO 20 KT RANGE WITH OCCASIONAL
GUSTS TO 25 KT POSSIBLE. THE FRONT SHOULD CLEAR THE SOUTH END OF THE
LAKE AROUND MIDNIGHT TONIGHT. WITH A DECENT FETCH DOWN THE
LAKE...WAVES ARE EXPECTED TO BUILD INTO THE 3 TO 6 FT RANGE AT THE
SOUTH END OF THE LAKE PROMPTING A SMALL CRAFT ADVISORY FOR MAINLY
THE ILLINOIS NEARSHORE WATERS LATE THIS EVENING AND OVERNIGHT.
THESE CONDITIONS SHOULD SUBSIDE BACK BELOW CRITERIA THURSDAY
AFTERNOON AS HIGH PRESSURE PASSES OVER THE LAKE. AS THE HIGH
SHIFTS OVER THE EASTERN LAKES FRIDAY...SOUTHERLY FLOW INCREASES
AGAIN ACROSS THE LAKE. ANOTHER FRONT IS EXPECTED TO SAG SOUTH
ACROSS THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
610 PM CDT Thu Sep 5 2013
.SHORT TERM...(This Evening through Friday)
Issued at 243 PM CDT THU SEP 5 2013
Upper level high remains centered over Colorado through tomorrow
while a surface high continues to retreat eastward. An area of
isolated showers has continued to move closer to our northern
areas...although most of the precip is not reaching the ground. The
12z NAM supports moisture convergence in this area along with an
axis of slight elevated instability which extends into northeast
Kansas. The HRRR has also been consistent with bringing these
showers into our area. If showers are able to persist within the dry
air and weak advection only northern row of counties look to be
affected the next few hours with an overall diminishing trend
towards the evening.
High temperatures look to reach the low to mid 90s today which is
above normal for this time of year. The skies will remain partly
cloudy especially across northern areas closer to the ongoing shower
activity. Tonight WAA will again set up across eastern Nebraska well
north of the northeast Kansas to keep the entire area dry. Low
temperatures tonight appear to be on track for the mid to upper 60s.
Low level winds will gradually veer allowing warming 850 temps to
spread into eastern KS therefore high temperatures will make it into
the low to mid 90s again tomorrow. With more mixing likely tomorrow
during the day winds will likely increase to around 10 mph with
gusts up to 20 mph possible.
.LONG TERM...(Friday Night through Thursday)
Issued at 243 PM CDT THU SEP 5 2013
The forecast for Friday night through Tuesday is essentially one
of persistence. Other than subtle day to day differences, the
weather pattern will be fairly stagnant through the period with a
large area of upper level high pressure slowly drifting from west
to east across the plains and into the Ohio valley. High
temperatures will be consistently in the 90s. The hottest day
currently appears to be Saturday with southwest surface winds, the
upper ridge almost directly overhead, and the warmest 850 temps of
the week in place all pointing to highs in the middle to upper
90s. There will be a couple of very weak upper disturbances that
may provide enough lift for a shower or thunderstorm, mainly
northeast of the local forecast area along a weak convergence
zone, late on Saturday. Will watch these features in future
forecasts but expect dry conditions for the most part through the
weekend.
There are a couple of stronger northern stream short wave troughs
that come over the top of the ridge next week. The trough crossing
the Dakotas on Monday will push a cold front to the south, but
expect this front to lose its forward progression and stall over
northern Nebraska. The second of the stronger troughs will cross
the Dakotas late Tuesday and should successfully push the cold
front through the forecast area by late Wednesday. Much of the
upper forcing will remain well to the north, and surface
convergence is not expected to be particularly strong, but may be
sufficient for scattered storms along the incoming front. Cooler
and drier air with almost meridional flow aloft will follow the
frontal passage and expect the end of next week to be both cooler
and dry.
&&
.AVIATION...(For the 00Z TAFs through 00Z Friday Evening)
Issued at 610 PM CDT THU SEP 5 2013
RAP and NAM forecast soundings maintain a dry layer in the lower
troposphere through the evening. Therefore anticipate VFR
conditions to prevail. Think this dry layer around 800MB will
cause the light precip to continue to diminish as it moves south,
which is supported by the latest HRRR showing the light precip
falling apart around 7 pm. At most there may be a sprinkle at the
terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1152 PM EDT THU SEP 5 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 410 PM EDT THU SEP 5 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE GREAT LAKES BETWEEN A TROUGH OVER NE CANADA AND A RIDGE
FROM COLORADO INTO THE WRN PLAINS. THE MAIN UPSTREAM SHORTWAVE
TROUGH OF INTEREST WAS MOVING INTO WEST CENTRAL SASK. AT THE
SFC...HIGH PRES WAS CENTERED OVER MI AND THE WRN GREAT LAKES
BRINGING CLEAR SKIES AND LIGHT WINDS TO THE REGION.
TONIGHT...MAINLY CLEAR SKIES THIS EVENING ARE EXPECTED TO GIVE WAY
TO INCREASING MID/HIGH CLOUDS LATE. TEMPS MAY DROP OFF QUICKLY AFTER
SUNSET BUT WITH INCREASING SW FLOW OVERNIGHT...TEMPS ARE EXPECTED TO
ONLY DROP TO AROUND CENTRAL 50 AND BECOME STEADY OR SLOWLY RISING IN
THE MID TO UPPER 50S WEST.
FRIDAY...THE SASK SHRTWV IS EXPECTED TO SLIDE JUST NORTH OF LAKE
SUPERIOR. HOWEVER...925-700 MB THETA-E ADVECTION AHEAD OF THIS
FEATURE AND ASSOCIATED 310K ISENTROPIC LIFT WILL SUPPORT SCT ELEVATED
SHRA/TSRA INTO N AND W LAKE SUPERIOR BY LATE MORNING THAT MAY SPREAD
INTO THE CNTRL AND EAST DURING THE AFTERNOON. THERE IS STILL ENOUGH
UNCERTAINTY WITH MDLS DIFFERING ON TIMING/POSITION OF THE PCPN TO
KEEP JUST CHANCE POPS. ALTHOUGH MUCAPE VALUES TO AROUND 1K J/KG
RANGE MAY SUPPORT SOME STRONGER STORMS...THE GREATER INSTABILITY
WITH MLCAPES OF 1000-1500 J/KG IS EXPECTED TO REMAIN UPSTREAM OVER
MN. EVEN WITH INCREASING CLOUDS AND PCPN POSSIBLE DURING THE
AFTERNOON...HIGH TEMPS SHOULD CLIMB INTO THE LOWER 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 410 PM EDT THU SEP 5 2013
MAIN FCST CONCERNS IN THE LONGER TERM REVOLVE ARND POPS ON FRI
NGT/SAT ASSOCIATED WITH PASSAGE OF SHRTWVS IN NW FLOW ALF BTWN THE
MEAN TROF OVER QUEBEC AND RIDGE IN THE PLAINS. FOCUS FOR LATER IN
THE WEEKEND TURNS TOWARD HI PRES BLDG INTO THE UPR LKS.
FRI NGT/SAT...A SHRTWV EMBEDDED IN THE NW FLOW ALF IS PROGGED TO
PASS NEAR THE UPR LKS IN THE EVNG...SO EXPECT THE BEST CHC OF
SHRA/TS TO BE IN THE EVNG WHEN ACCOMPANYING PVA INTERACTS WITH AXIS
OF HIER H85 THETA E. MID LVL DRYING/NEGATIVE H85 THETA E AVCTN IN
THE WAKE OF THIS INITIAL SHRTWV PASSAGE WL THEN RESULT IN
DIMINISHING POPS NW-SE THRU SAT MRNG...BUT APRCH OF ANOTHER SHRTWV
IN THE NW FLOW ALF WARRANTS AT LEAST A SCHC OF LINGERING SHRA. THE
12Z GFS AND ESPECIALLY THE 00Z CNDN MODELS ARE SLOWER/STRONGER THAN
THE BULK OF THE OTHER GUIDANCE WITH THIS TRAILING
DISTURBANCE...LINGERING DEEP LYR QVECTOR CNVGC AND QPF THRU MOST OF
THE DAY ON SAT...SO RETAINED SOME LO CHC POPS ESPECIALLY OVER THE
SCENTRAL THRU THE ENTIRE DAY.
SAT NGT THRU SUN...CNDN HI PRES UNDER CONFLUENT NW FLOW ALF BTWN THE
TROF IN QUEBEC/RDG IN THE PLAINS IS PROGGED TO SHIFT FM MANITOBA AT
00Z SUN TO OVER LK SUP SUN AFTN. UNDER LARGER SCALE SUBSIDENCE AND
PWAT FCST AOB 0.50 INCH...DRY WX WL PREVAIL. THE ONLY CONCERN IS
WHETHER THERE WL BE ANY LO CLDS AT LEAST FOR A TIME NEAR LK SUP WITH
UPSLOPE NNE FLOW UNDER SHARP SUBSIDENCE INVRN H85-9 IN ADVANCE OF
THE INCOMING SFC HI AS SUGGESTED BY THE 06Z AND 12Z GFS RUNS. GIVEN
LARGE SCALE ACYC LLVL FLOW...DRY NATURE OF INCOMING AIRMASS AND
MARGINAL CHILL OF THIS AIRMASS FOR LK CLDS /H925 TEMPS NO LOWER THAN
6-7C OVER THE E HALF COMPARED TO OPEN WATER TEMPS 14-15C/...
RESTRICTED FCST OF SCT-BKN LO CLDS TO THE HIER TERRAIN OF THE
NCENTRAL EARLY SUN MRNG PER THE MORE PESSIMISTIC GFS FCST SDNGS AND
BEFORE DAYTIME HEATING WOULD MIX THESE CLDS OUT ON SUN AFTN. TEMPS
ON SUN MRNG/AFTN WL BE COOLER THAN THE DAY BEFORE WITH H85 TEMPS
FCST BTWN 5-10C DURING THIS PERIOD. EXPECT THE LOWEST MIN TEMPS ON
SUN MRNG OVER THE INTERIOR W...WITH NNE FLOW OFF LK SUP KEEPING
AREAS NEAR THE SHORE WARMER.
SUN NGT...AS SFC HI PRES DRIFTS OVER NY STATE BY 12Z SUN...A RETURN
SLY FLOW OF WARMER/MOISTER AIR BTWN THIS FEATURE AND A SHRTWV/
ACCOMPANYING SFC LO MOVING INTO THE NRN PLAINS WL DVLP OVER THE UPR
LKS. SO EXPECT AT LEAST SOME INCRS IN CLDS AND A WARMER OVERNGT.
RESTRICTED POPS TO THE FAR WRN CWA GIVEN MODEL QPF/LINGERING LLVL
DRY AIR OVER MOST OF THE CWA.
MON INTO TUE...AS SHRTWV IN THE NRN PLAINS AND ATTENDANT SFC LO PRES/
WARM FNT MOVE TOWARD THE UPR LKS...EXPECT SHRA/TS CHCS TO INCRS OVER
THE CWA. NOT SURPRISINGLY...THE EXTENDED MODELS DISAGREE ON THE
EXACT TRACK OF THE SFC LO/WARM FNT AND AXIS OF HIER QPF. THE 12Z AND
ESPECIALLY THE 00Z CNDN MODELS ARE FARTHER N WITH THE SFC LO TRACK/
WARM FNT AND FCSTS THE BULK OF ANY ACCOMPANYING SHRA/TS TO REMAIN N
OF UPR MI WHILE THE 06Z GFS FCSTS HEAVY PCPN WITH THE SFC LO
TRACKING E THRU THE CWA OVER THE WARM FNT ON MON INTO EARLY TUE. THE
RESULT OF THIS SCENARIO WOULD BE A WARM SUMMER-LIKE DAY WITH A GOOD
DEAL OF SUNSHINE AND H85/SFC TEMPS NEAR 20C/WELL INTO THE 80S AWAY
FM LK MODERATION IN LLVL SW FLOW. SHRA/TS WITH HEAVY RA/PSBL SEVERE
TS WOULD BE THE RESULT IF THE GFS MODEL VERIFIES. THE 12Z GFS/00Z
ECWMF RUNS ARE A COMPROMISE BTWN THOSE TWO CAMPS AND ALSO INDICATE
THE POTENTIAL FOR SEVERE TS WITH FCST H85 TEMPS UP TO 20C AND SSI AS
LO AS -3 TO -4C UNDER STRONGER H5 FLOW. GIVEN THESE UNCERTAINTIES...
MAINTAINED CONSENSUS FCST FOR NOW.
EXTENDED...AS AN UPR TROF DEEPENS INTO THE GREAT LKS ON WED BEHIND
DEPARTING SHRTWV RESPONSIBLE FOR THE MON/TUE POPS...EXPECT SHRA/TS
CHCS TO PERSIST. EXPECT COOLER/DRIER WX TO SPREAD TO THE E NEXT
THU/FRI AS HI PRES BLDS TOWARD THE PLAINS/WRN GRT LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1149 PM EDT THU SEP 5 2013
WITH HIGH PRESSURE OVER THE REGION...EXPECT VFR CONDITIONS AND LIGHT
WINDS THROUGH MOST OF TONIGHT. MID CLOUDS WILL BEGIN TO THICKEN
AFTER MIDNIGHT AT CMX...BUT ANY SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO HOLD OFF UNTIL FRIDAY AFTERNOON. THE BETTER CHC FOR
SHRA/TSRA WILL BE AT KCMX AND KSAW MID TO LATE AFTERNOON INTO THE
EVENING HOURS. MENTIONED ONLY VICINITY SHRA AT KIWD AS THEY WILL BE
FARTHER REMOVED FROM BEST FORCING FOR SHRA/TSRA ACTIVITY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EDT THU SEP 5 2013
EXPECT SW WINDS UP TO 20-25 KTS ON FRI UNDER SHARPENING PRES
GRADIENT AHEAD OF INCOMING LO PRES TROUGH. FOLLOWING THE PASSAGE OF
A COLD FRONT ON SAT...WINDS WILL VEER TO THE N-NE AND REMAIN UP TO
20 KTS INTO SUN IN ADVANCE OF HI PRES BUILDING TOWARD THE GREAT
LAKES. A RELATIVELY WEAK PRES GRADIENT AND/OR HI OVERWATER STABILITY
WILL THEN DOMINATE ON SUN INTO TUE...RESULTING IN WINDS UNDER 20 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EDT WED SEP 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 407 PM EDT WED SEP 4 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL THROUGH THE
UPPER GREAT LAKES BETWEEN A LOW OVER NRN QUEBEC AND A RIDGE FROM
COLORADO THROUGH THE WRN PLAINS. WITH CONFLUENT FLOW AND 700-300 MB
QVECTOR DIV BUILDING INTO THE AREA...EXPECT MAINLY CLEAR SKIES TO
PREVAIL WITH ONLY SOME BANDS OF CIRRUS THROUGH THE ERN CWA...PER VIS
IMAGERY. AT THE SFC...HIGH PRES FROM SRN MANITOBA INTO NW ONTARIO
WAS BUILDING INTO THE NRN GREAT LAKES WITH INFLUX OF DRY AIR ON NRN
ACYC FLOW. LOWER DEWPOINTS UPSTREAM FROM LAKE SUPERIOR (READINGS IN
THE UPPER 30S) WERE FILTERING TOWARD UPPER MI.
TONIGHT...EVEN WITH PWAT VALUES AROUND 0.50 INCH CLIMBING TO NEAR
0.75 INCH...WITH HIGH PRES BUILDING INTO UPPER MI...MOSTLY CLEAR
SKIES AND LIGHT WINDS ALLOW TEMPS TO DROP OFF TOWARD THE LOWER END
OF GUIDANCE. READINGS INTO THE UPPER 30S INLAND WEST AND LOW TO MID
40S OVER THE EAST AND ALONG THE GREAT LAKES ARE EXPECTED. PATCHY
FROST MAY BE POSSIBLE IN THE TYPICAL COLD SPOTS FROM REPUBLIC AND
CHAMPION TO AMASA...IRON RIVER AND WATERSMEET.
THURSDAY...UNDER ABUNDANT SUNSHINE WITH 850 MB TEMPS IN THE 6C TO
10C RANGE...TEMPS WILL REBOUND CLOSER TO SEASONAL AVERAGES WITH HIGHS
RANGING FROM THE UPPER 60S EAST TO THE LOWER 70S WEST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 407 PM EDT WED SEP 4 2013
HIGH PRESSURE WILL KEEP WEATHER QUIET THURSDAY NIGHT THROUGH EARLY
FRIDAY AFTERNOON. AS THE HIGH CENTERS OVER THE EASTERN
SEABOARD...UPPER MICHIGAN IS POSITIONED ON THE NORTHWESTERN
PERIPHERY OF THE RIDGE...MAKING US VULNERABLE FOR WEAK WAVES TO
SLIDE THROUGH. THE FIRST OF THESE SLIDES OUT AHEAD OF THE MAIN
TROUGH ON FRIDAY AFTERNOON. MODELS ARE MOSTLY IN AGREEMENT...WITH
THE EXCEPTION OF THE GFS WHICH BRINGS THE MAIN TROUGH IN MUCH
QUICKER...SO STRAYED FROM THAT SOLUTION. USED PRIMARILY THE
GEM/ECMWF FOR THIS LONG TERM FORECAST.
WEAK MOISTURE ADVECTION/CONVERGENCE SHOWS UP FOR THE MID LEVELS AND
FOCUSES ACROSS THE WEST AND NORTHERN PORTIONS OF THE CWA EARLIER IN
THE DAY...PRIMARILY OVER THE KEWEENAW AND LAKE SUPERIOR. THROUGHOUT
THE DAY THIS REGION MOVES EAST-SOUTHEASTWARD TOWARDS QUEBEC...SO
KEPT PCP CHANCES FAR EAST INTO FRIDAY EVENING. OVERALL...850-500MB
QVECTOR CONVERGENCE IS PALTRY BUT WARRANTS SOME SLIGHT CHANCE/CHANCE
POPS. LOW LEVELS ARE FAIRLY DRY THOUGH...AND INSTABILITY IS MINIMAL.
WILL KEEP THE POPS PRIMARILY OVER THE LAKE AND FAR EAST FOR NOW.
FRIDAY NIGHT THROUGH SATURDAY THE STRONGER TROUGH MOVES THROUGH THE
GREAT LAKES AS LOW PRESSURE OVER JAMES BAY ON FRIDAY MOVES INTO
QUEBEC. MOISTURE IS DEEPER AND INSTABILITY IS GREATER THIS GO
AROUND...WHICH WILL SUPPORT SHOWERS AND TSTORMS ACROSS THE CWA. THE
WESTERN CWA IS LIKELY TO SEE SHOWERS/A FEW TSTORMS STARTING LATER
FRIDAY NIGHT AND CONTINUING THROUGH MAINLY SATURDAY MORNING. WITH
GREATER INSTABILITY BUILDING TOWARDS SATURDAY AFTERNOON ALONG THE WI
BORDER AND CENTRAL U.P. LINGERED CHANCE POPS THERE THROUGH THE
AFTERNOON.
THE BEST MOISTURE IS CENTRAL AND EAST HOWEVER...AND SFC BASED CAPE
IS AROUND 1000-500 J/KG FOR THE AFTERNOON. WITH THE FRONT PASSING
THROUGH THE CENTRAL CWA AROUND 18Z AND NORTHWEST FLOW ALOFT...EXPECT
WE WILL SEE SOME ACTIVITY. 0-6KM BULK SHEAR IS AROUND 20-30
KNOTS...SO DO NOT EXPECT ANYTHING TOO GET TOO ORGANIZED. ANY SEVERE
THREAT AS OF RIGHT NOW LOOKS TO BE VERY ISOLATED.
ON SUNDAY HIGH PRESSURE BRINGS A BRIEF BREAK TO THE PRECIPITATION.
MONDAY AND TUESDAY A WARM FRONT LIFTS ACROSS THE MIDWEST WITH A
STRONGER LOW PRESSURE SYSTEM IN THE NORTHERN PLAINS. THIS LOW WILL
MOVE NORTHEASTWARD INTO ONTARIO...AND EVENTUALLY BRING A COLD FRONT
ACROSS UPPER MI ON WEDNESDAY. HAVE CHANCE POPS IN THE FORECAST FOR
NOW...GIVEN DIFFERENCES BETWEEN MODELS IN THE LOCATION OF THE LOW
PRESSURE SYSTEM DURING THESE TIMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 139 PM EDT WED SEP 4 2013
ANY LEFTOVER MVFR CIGS AT IWD ARE EXPECTED TO DEPART EARLY THIS
AFTERNOON AS DRIER AIR MOVES IN. OTHERWISE...WITH HIGH PRESSURE
BUILDING INTO THE REGION...EXPECT VFR CONDITIONS AND LIGHT WINDS
THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT WED SEP 4 2013
WITH HIGH PRES BUILDING INTO THE UPPER LAKES...WINDS WILL DIMINISH
TO LESS THAN 20 KTS LATER TONIGHT INTO THURSDAY. SW WINDS WILL
INCREASE ON FRIDAY IN THE TIGHTER PRESSURE GRADIENT BETWEEN THE
EXITING HIGH PRESSURE AND A COLD FRONT THAT ARRIVES THIS WEEKEND.
EXPECT WINDS ON FRIDAY TO STAY LESS THAN 25 KTS. WINDS FOR THE
REMAINDER OF THE FORECAST PERIOD WILL REMAIN LESS THAN 20 KNOTS DUE
TO WEAKER PRESSURE GRADIENT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1038 AM CDT WED SEP 4 2013
.UPDATE...
ISSUED AT 1032 AM CDT WED SEP 4 2013
...UPDATED TODAY...
UPDATES FOR TODAY HAVE TO DO WITH STRONG OFF-LAKE WINDS. CLOUDS
NEAR LAKE WILL BE HANGING ON A BIT LONGER THAN PREVIOUS FORECAST.
CURRENT VIS SAT DOES SHOW THE CLOUDS THINNING A BREAKING UP BUT
BUFR SOUNDINGS INDICATE CLEARING A FEW HOURS LATER THAT
FCST...ABOUT MID AFTERNOON. ALSO UPDATED TO REFLECT THE STRONGER
WINDS AND COOLER TEMPS AT THE LAKE. LATEST LIFT BRIDGE OB HAD 56
DEGREES WITH 21 MPH WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT WED SEP 4 2013
AT 345AM/0845Z...A COLD FRONT STRETCHED FROM EAST TO WEST ACROSS
LAKE SUPERIOR...NORTHERN MINNESOTA...AND SOUTHEASTERN NORTH
DAKOTA. STRONG SURFACE HIGH PRESSURE WAS CENTERED NEAR SOUTHERN
MANITOBA. A LARGE MID/UPPER LEVEL RIDGE WAS CENTERED NEAR
COLORADO/KANSAS WITH THE AXIS EXTENDING NORTH TO CENTRAL MONTANA
AND INTO WESTERN CANADA. MUCH OF THE NORTHLAND HAD LIGHT TO NEARLY
CALM WINDS...BUT 5 TO 10 KNOT NORTHERLY WINDS WERE DEVELOPING
ACROSS FAR NORTHERN MINNESOTA IN THE WAKE OF THE COLD FRONT.
TEMPERATURES RANGED FROM THE MID 50S TO MID 60S...WITH MOST OF THE
NORTHLAND IN THE UPPER 50S AND LOWER 60S. THERE WERE INCREASING
PATCHES OF BKN/OVC LOW LEVEL CLOUDS ACROSS THE EASTERN AND
SOUTHERN FORECAST AREAS...ESPECIALLY OVER THE ARROWHEAD AND LAKE
SUPERIOR.
EARLY THIS MORNING...THE COLD FRONT WILL CONTINUE MOVING SOUTH
THROUGH THE NORTHLAND. BASED ON THE HRRR AND RAP...IT APPEARS
THERE WILL BE INCREASING CLOUD COVER OVER LAKE SUPERIOR AND PARTS
OF THE SOUTHERN FORECAST AREA IN THE WAKE OF THE COLD FRONT. IN
THE CASE OF LAKE SUPERIOR AND NW WISCONSIN...THIS IS LIKELY DUE TO
THE ADDED MOISTURE THE INCREASING NORTHERLY WINDS WILL PROVIDE
FROM LAKE SUPERIOR. I RAISED THE MORNING LOW TEMPERATURES A BIT
BECAUSE THE LIGHT WINDS ACROSS THE NORTHLAND AND THE MOISTURE
COMPRESSION NEAR THE FRONT SEEM TO BE PREVENTING THE TEMPERATURES
FROM FALLING MUCH THIS MORNING.
TODAY...THE SURFACE HIGH PRESSURE IN SOUTHERN MANITOBA WILL MOVE
OVER NORTHERN MINNESOTA. THIS SHOULD PROVIDE MOSTLY TO PARTLY
SUNNY SKIES FOR THE NORTHLAND AFTER THE LINGERING MORNING BKN/OVC
LOW LEVEL CLOUDS DISSIPATE. THERE MAY BE SOME MID/HIGH LEVEL
CLOUDS ACROSS THE SOUTHERN AND WESTERN FORECAST AREA AS THE MODELS
SHOW SOME SATURATION ALOFT ALONG SOME WEAK CHANNELED VORTICITY
STRETCHING FROM THE UPPER MIDWEST TO SOUTH CENTRAL CANADA ON THE
EASTERN SIDE OF A MID/UPPER LEVEL RIDGE. HIGH TEMPERATURES SHOULD
RANGE THE MID 60S TO MID 70S WITH THE COOLER TEMPERATURES ACROSS
NORTHERN MINNESOTA.
TONIGHT...THE SURFACE HIGH PRESSURE WILL BEGIN TO SHIFT TOWARD
NORTHERN WISCONSIN AND LAKE MICHIGAN. THE NORTHLAND CAN EXPECT
CLEAR TO MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. THE COLD
FRONT WILL USHER IN LOW DEW POINT TEMPERATURES...AND THIS COMBINED
WITH THE LACK OF WINDS AND CLOUDS...WILL ALLOW TEMPERATURES TO
DROP QUITE A BIT. MUCH OF INLAND NORTHERN MINNESOTA AND PARTS OF
INLAND NW WISCONSIN SHOULD SEE TEMPERATURES DROP TO THE UPPER 30S
AND LOW 40S. THIS MEANS SOME AREAS COULD SEE FROST AND WE WILL
NEED TO CONSIDER THE NEED FOR A FROST ADVISORY. HOWEVER...THE MOST
RECENT MODELS SHOW SLIGHTLY HIGHER DEW POINT
TEMPERATURES...ESPECIALLY OVER NW WISCONSIN...COMPARED TO THE
PREVIOUS FORECAST. ALSO...I SLIGHTLY RAISED TEMPERATURES. I AM NOT
CONFIDENT OF ANY WIDESPREAD FROST...SO I KICK THE CAN TO THE DAY
SHIFT TO MAKE A FINAL DECISION ON A FROST ADVISORY. THE MOST
LIKELY AREA FOR FROST IS ACROSS THE IRON RANGE AND THE INTERIOR
ARROWHEAD.
THURSDAY...THE SURFACE HIGH PRESSURE WILL SHIFT EAST TO THE
MICHIGAN AND THE EASTERN GREAT LAKES. LIGHT SOUTHERLY FLOW OVER
THE NORTHLAND AND SUNNY SKIES WILL PROVIDE A WARMER DAY WITH
TEMPERATURES REACHING THE UPPER 60S TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED SEP 4 2013
THURSDAY NIGHT OUR SURFACE RIDGE SLIPS OFF TO THE SOUTHEAST
AGAIN...WITH SOUTHWEST FLOW BEGINNING AGAIN OVER THE FORECAST
AREA. THIS SHOULD KEEP OUR TEMPERATURES UP IN THE 50S OVERNIGHT.
A SHORTWAVE DIVING THROUGH THE NORTHWEST UPPER LEVEL FLOW MAY
BRING A FEW SHOWERS AND THUNDERSTORMS TO THE AREA OVERNIGHT...BUT
THIS WILL BE LIMITED TO THE FAR NORTHERN SECTIONS OF THE AREA. WE
ARE JUST GOING TO GET A GLANCING BLOW...SO HAVE KEPT POPS IN THE
SLIGHT CHANCE CATEGORY BOTH THURSDAY NIGHT AND FRIDAY. HIGHS
FRIDAY TO BE WARM AS WELL...IN THE LOW TO MID 80S.
FRIDAY NIGHT THROUGH SATURDAY TO BE ACTIVE WITH A FEW MORE
SHORTWAVE OVERTOPPING THE UPPER LEVEL RIDGE OVER THE ROCKIES...AND
A COLD FRONT DROPS THROUGH THE AREA FRIDAY NIGHT AND SATURDAY AS
WELL. HAVE SOME SLIGHT CHANCE AND CHANCE POPS GOING...WHICH MAY BE
RAISED AS DETAILS BECOME CLEAR. WARM TEMPERATURES ARE EXPECTED TO
CONTINUE. SATURDAY NIGHT SHOULD BE QUIET AND DRIER.
BEGINNING SUNDAY UNCERTAINTY INCREASES OVER THE AREA WITH THE
UPPER LEVEL RIDGE FLATTENING AND SHIFTING EAST...ALLOWING A
FAIRLY STRONG SHORTWAVE TO MOVE ACROSS THE AREA IN THE TUESDAY-
WEDNESDAY TIME RANGE. MODELS HAVE VARYING SOLUTIONS...BUT
GENERALLY TEMPERATURES COOL OFF BACK TOWARDS NORMAL VALUES
AGAIN...WITH PRECIPITATION CHANCES BEGINNING SUNDAY AND CONTINUING
THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 653 AM CDT WED SEP 4 2013
A COLD FRONT IN THE PROCESS OF MOVING THROUGHT THE TERMINALS THIS
MORNING. BEHIND THE FRONT LIGHT NORTH WINDS ARE BEGINNING TO
SETTLE IN. WINDS ARE STRONGER OVER THE LAKE AND MVFR STRATUS THAT
FORMED OVER THE LAKE HAS ADVECTED OVER KDLH...AND IS CLOSE TO
MOVING INTO KHYR. KHIB A LITTLE FARTHER AWAY/LESS CERTAIN. THIS
STRATUS TO AFFECT THESE THREE TERMINALS THROUGH ABOUT 18Z BEFORE
BECOMING SCATTERED THIS AFTERNOON. REMAINING TERMINALS TO STAY
VFR. ONCE VFR CONDITIONS RETURN THIS AFTERNOON EXPECT THEM TO STAY
THAT WAY THROUGH 12Z THURSDAY MORNING AS A STRONG SURFACE RIDGE
MOVES ACROSS THE AREA TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 68 44 74 56 / 0 0 0 10
INL 67 39 77 56 / 0 0 0 20
BRD 76 46 80 60 / 0 0 0 0
HYR 73 39 78 55 / 0 0 0 0
ASX 66 41 74 56 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
142>148.
&&
$$
UPDATE...CLC
AREA FORECAST DISCUSSION
NWS DULUTH MN
654 AM CDT WED SEP 4 2013
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT WED SEP 4 2013
AT 345AM/0845Z...A COLD FRONT STRETCHED FROM EAST TO WEST ACROSS
LAKE SUPERIOR...NORTHERN MINNESOTA...AND SOUTHEASTERN NORTH
DAKOTA. STRONG SURFACE HIGH PRESSURE WAS CENTERED NEAR SOUTHERN
MANITOBA. A LARGE MID/UPPER LEVEL RIDGE WAS CENTERED NEAR
COLORADO/KANSAS WITH THE AXIS EXTENDING NORTH TO CENTRAL MONTANA
AND INTO WESTERN CANADA. MUCH OF THE NORTHLAND HAD LIGHT TO NEARLY
CALM WINDS...BUT 5 TO 10 KNOT NORTHERLY WINDS WERE DEVELOPING
ACROSS FAR NORTHERN MINNESOTA IN THE WAKE OF THE COLD FRONT.
TEMPERATURES RANGED FROM THE MID 50S TO MID 60S...WITH MOST OF THE
NORTHLAND IN THE UPPER 50S AND LOWER 60S. THERE WERE INCREASING
PATCHES OF BKN/OVC LOW LEVEL CLOUDS ACROSS THE EASTERN AND
SOUTHERN FORECAST AREAS...ESPECIALLY OVER THE ARROWHEAD AND LAKE
SUPERIOR.
EARLY THIS MORNING...THE COLD FRONT WILL CONTINUE MOVING SOUTH
THROUGH THE NORTHLAND. BASED ON THE HRRR AND RAP...IT APPEARS
THERE WILL BE INCREASING CLOUD COVER OVER LAKE SUPERIOR AND PARTS
OF THE SOUTHERN FORECAST AREA IN THE WAKE OF THE COLD FRONT. IN
THE CASE OF LAKE SUPERIOR AND NW WISCONSIN...THIS IS LIKELY DUE TO
THE ADDED MOISTURE THE INCREASING NORTHERLY WINDS WILL PROVIDE
FROM LAKE SUPERIOR. I RAISED THE MORNING LOW TEMPERATURES A BIT
BECAUSE THE LIGHT WINDS ACROSS THE NORTHLAND AND THE MOISTURE
COMPRESSION NEAR THE FRONT SEEM TO BE PREVENTING THE TEMPERATURES
FROM FALLING MUCH THIS MORNING.
TODAY...THE SURFACE HIGH PRESSURE IN SOUTHERN MANITOBA WILL MOVE
OVER NORTHERN MINNESOTA. THIS SHOULD PROVIDE MOSTLY TO PARTLY
SUNNY SKIES FOR THE NORTHLAND AFTER THE LINGERING MORNING BKN/OVC
LOW LEVEL CLOUDS DISSIPATE. THERE MAY BE SOME MID/HIGH LEVEL
CLOUDS ACROSS THE SOUTHERN AND WESTERN FORECAST AREA AS THE MODELS
SHOW SOME SATURATION ALOFT ALONG SOME WEAK CHANNELED VORTICITY
STRETCHING FROM THE UPPER MIDWEST TO SOUTH CENTRAL CANADA ON THE
EASTERN SIDE OF A MID/UPPER LEVEL RIDGE. HIGH TEMPERATURES SHOULD
RANGE THE MID 60S TO MID 70S WITH THE COOLER TEMPERATURES ACROSS
NORTHERN MINNESOTA.
TONIGHT...THE SURFACE HIGH PRESSURE WILL BEGIN TO SHIFT TOWARD
NORTHERN WISCONSIN AND LAKE MICHIGAN. THE NORTHLAND CAN EXPECT
CLEAR TO MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. THE COLD
FRONT WILL USHER IN LOW DEW POINT TEMPERATURES...AND THIS COMBINED
WITH THE LACK OF WINDS AND CLOUDS...WILL ALLOW TEMPERATURES TO
DROP QUITE A BIT. MUCH OF INLAND NORTHERN MINNESOTA AND PARTS OF
INLAND NW WISCONSIN SHOULD SEE TEMPERATURES DROP TO THE UPPER 30S
AND LOW 40S. THIS MEANS SOME AREAS COULD SEE FROST AND WE WILL
NEED TO CONSIDER THE NEED FOR A FROST ADVISORY. HOWEVER...THE MOST
RECENT MODELS SHOW SLIGHTLY HIGHER DEW POINT
TEMPERATURES...ESPECIALLY OVER NW WISCONSIN...COMPARED TO THE
PREVIOUS FORECAST. ALSO...I SLIGHTLY RAISED TEMPERATURES. I AM NOT
CONFIDENT OF ANY WIDESPREAD FROST...SO I KICK THE CAN TO THE DAY
SHIFT TO MAKE A FINAL DECISION ON A FROST ADVISORY. THE MOST
LIKELY AREA FOR FROST IS ACROSS THE IRON RANGE AND THE INTERIOR
ARROWHEAD.
THURSDAY...THE SURFACE HIGH PRESSURE WILL SHIFT EAST TO THE
MICHIGAN AND THE EASTERN GREAT LAKES. LIGHT SOUTHERLY FLOW OVER
THE NORTHLAND AND SUNNY SKIES WILL PROVIDE A WARMER DAY WITH
TEMPERATURES REACHING THE UPPER 60S TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED SEP 4 2013
THURSDAY NIGHT OUR SURFACE RIDGE SLIPS OFF TO THE SOUTHEAST
AGAIN...WITH SOUTHWEST FLOW BEGINNING AGAIN OVER THE FORECAST
AREA. THIS SHOULD KEEP OUR TEMPERATURES UP IN THE 50S OVERNIGHT.
A SHORTWAVE DIVING THROUGH THE NORTHWEST UPPER LEVEL FLOW MAY
BRING A FEW SHOWERS AND THUNDERSTORMS TO THE AREA OVERNIGHT...BUT
THIS WILL BE LIMITED TO THE FAR NORTHERN SECTIONS OF THE AREA. WE
ARE JUST GOING TO GET A GLANCING BLOW...SO HAVE KEPT POPS IN THE
SLIGHT CHANCE CATEGORY BOTH THURSDAY NIGHT AND FRIDAY. HIGHS
FRIDAY TO BE WARM AS WELL...IN THE LOW TO MID 80S.
FRIDAY NIGHT THROUGH SATURDAY TO BE ACTIVE WITH A FEW MORE
SHORTWAVE OVERTOPPING THE UPPER LEVEL RIDGE OVER THE ROCKIES...AND
A COLD FRONT DROPS THROUGH THE AREA FRIDAY NIGHT AND SATURDAY AS
WELL. HAVE SOME SLIGHT CHANCE AND CHANCE POPS GOING...WHICH MAY BE
RAISED AS DETAILS BECOME CLEAR. WARM TEMPERATURES ARE EXPECTED TO
CONTINUE. SATURDAY NIGHT SHOULD BE QUIET AND DRIER.
BEGINNING SUNDAY UNCERTAINTY INCREASES OVER THE AREA WITH THE
UPPER LEVEL RIDGE FLATTENING AND SHIFTING EAST...ALLOWING A
FAIRLY STRONG SHORTWAVE TO MOVE ACROSS THE AREA IN THE TUESDAY-
WEDNESDAY TIME RANGE. MODELS HAVE VARYING SOLUTIONS...BUT
GENERALLY TEMPERATURES COOL OFF BACK TOWARDS NORMAL VALUES
AGAIN...WITH PRECIPITATION CHANCES BEGINNING SUNDAY AND CONTINUING
THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 653 AM CDT WED SEP 4 2013
A COLD FRONT IN THE PROCESS OF MOVING THROUGHT THE TERMINALS THIS
MORNING. BEHIND THE FRONT LIGHT NORTH WINDS ARE BEGINNING TO
SETTLE IN. WINDS ARE STRONGER OVER THE LAKE AND MVFR STRATUS THAT
FORMED OVER THE LAKE HAS ADVECTED OVER KDLH...AND IS CLOSE TO
MOVING INTO KHYR. KHIB A LITTLE FARTHER AWAY/LESS CERTAIN. THIS
STRATUS TO AFFECT THESE THREE TERMINALS THROUGH ABOUT 18Z BEFORE
BECOMING SCATTERED THIS AFTERNOON. REMAINING TERMINALS TO STAY
VFR. ONCE VFR CONDITIONS RETURN THIS AFTERNOON EXPECT THEM TO STAY
THAT WAY THROUGH 12Z THURSDAY MORNING AS A STRONG SURFACE RIDGE
MOVES ACROSS THE AREA TONIGHT.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
142>148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
350 AM CDT WED SEP 4 2013
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT WED SEP 4 2013
AT 345AM/0845Z...A COLD FRONT STRETCHED FROM EAST TO WEST ACROSS
LAKE SUPERIOR...NORTHERN MINNESOTA...AND SOUTHEASTERN NORTH
DAKOTA. STRONG SURFACE HIGH PRESSURE WAS CENTERED NEAR SOUTHERN
MANITOBA. A LARGE MID/UPPER LEVEL RIDGE WAS CENTERED NEAR
COLORADO/KANSAS WITH THE AXIS EXTENDING NORTH TO CENTRAL MONTANA
AND INTO WESTERN CANADA. MUCH OF THE NORTHLAND HAD LIGHT TO NEARLY
CALM WINDS...BUT 5 TO 10 KNOT NORTHERLY WINDS WERE DEVELOPING
ACROSS FAR NORTHERN MINNESOTA IN THE WAKE OF THE COLD FRONT.
TEMPERATURES RANGED FROM THE MID 50S TO MID 60S...WITH MOST OF THE
NORTHLAND IN THE UPPER 50S AND LOWER 60S. THERE WERE INCREASING
PATCHES OF BKN/OVC LOW LEVEL CLOUDS ACROSS THE EASTERN AND
SOUTHERN FORECAST AREAS...ESPECIALLY OVER THE ARROWHEAD AND LAKE
SUPERIOR.
EARLY THIS MORNING...THE COLD FRONT WILL CONTINUE MOVING SOUTH
THROUGH THE NORTHLAND. BASED ON THE HRRR AND RAP...IT APPEARS
THERE WILL BE INCREASING CLOUD COVER OVER LAKE SUPERIOR AND PARTS
OF THE SOUTHERN FORECAST AREA IN THE WAKE OF THE COLD FRONT. IN
THE CASE OF LAKE SUPERIOR AND NW WISCONSIN...THIS IS LIKELY DUE TO
THE ADDED MOISTURE THE INCREASING NORTHERLY WINDS WILL PROVIDE
FROM LAKE SUPERIOR. I RAISED THE MORNING LOW TEMPERATURES A BIT
BECAUSE THE LIGHT WINDS ACROSS THE NORTHLAND AND THE MOISTURE
COMPRESSION NEAR THE FRONT SEEM TO BE PREVENTING THE TEMPERATURES
FROM FALLING MUCH THIS MORNING.
TODAY...THE SURFACE HIGH PRESSURE IN SOUTHERN MANITOBA WILL MOVE
OVER NORTHERN MINNESOTA. THIS SHOULD PROVIDE MOSTLY TO PARTLY
SUNNY SKIES FOR THE NORTHLAND AFTER THE LINGERING MORNING BKN/OVC
LOW LEVEL CLOUDS DISSIPATE. THERE MAY BE SOME MID/HIGH LEVEL
CLOUDS ACROSS THE SOUTHERN AND WESTERN FORECAST AREA AS THE MODELS
SHOW SOME SATURATION ALOFT ALONG SOME WEAK CHANNELED VORTICITY
STRETCHING FROM THE UPPER MIDWEST TO SOUTH CENTRAL CANADA ON THE
EASTERN SIDE OF A MID/UPPER LEVEL RIDGE. HIGH TEMPERATURES SHOULD
RANGE THE MID 60S TO MID 70S WITH THE COOLER TEMPERATURES ACROSS
NORTHERN MINNESOTA.
TONIGHT...THE SURFACE HIGH PRESSURE WILL BEGIN TO SHIFT TOWARD
NORTHERN WISCONSIN AND LAKE MICHIGAN. THE NORTHLAND CAN EXPECT
CLEAR TO MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. THE COLD
FRONT WILL USHER IN LOW DEW POINT TEMPERATURES...AND THIS COMBINED
WITH THE LACK OF WINDS AND CLOUDS...WILL ALLOW TEMPERATURES TO
DROP QUITE A BIT. MUCH OF INLAND NORTHERN MINNESOTA AND PARTS OF
INLAND NW WISCONSIN SHOULD SEE TEMPERATURES DROP TO THE UPPER 30S
AND LOW 40S. THIS MEANS SOME AREAS COULD SEE FROST AND WE WILL
NEED TO CONSIDER THE NEED FOR A FROST ADVISORY. HOWEVER...THE MOST
RECENT MODELS SHOW SLIGHTLY HIGHER DEW POINT
TEMPERATURES...ESPECIALLY OVER NW WISCONSIN...COMPARED TO THE
PREVIOUS FORECAST. ALSO...I SLIGHTLY RAISED TEMPERATURES. I AM NOT
CONFIDENT OF ANY WIDESPREAD FROST...SO I KICK THE CAN TO THE DAY
SHIFT TO MAKE A FINAL DECISION ON A FROST ADVISORY. THE MOST
LIKELY AREA FOR FROST IS ACROSS THE IRON RANGE AND THE INTERIOR
ARROWHEAD.
THURSDAY...THE SURFACE HIGH PRESSURE WILL SHIFT EAST TO THE
MICHIGAN AND THE EASTERN GREAT LAKES. LIGHT SOUTHERLY FLOW OVER
THE NORTHLAND AND SUNNY SKIES WILL PROVIDE A WARMER DAY WITH
TEMPERATURES REACHING THE UPPER 60S TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED SEP 4 2013
THURSDAY NIGHT OUR SURFACE RIDGE SLIPS OFF TO THE SOUTHEAST
AGAIN...WITH SOUTHWEST FLOW BEGINNING AGAIN OVER THE FORECAST
AREA. THIS SHOULD KEEP OUR TEMPERATURES UP IN THE 50S OVERNIGHT.
A SHORTWAVE DIVING THROUGH THE NORTHWEST UPPER LEVEL FLOW MAY
BRING A FEW SHOWERS AND THUNDERSTORMS TO THE AREA OVERNIGHT...BUT
THIS WILL BE LIMITED TO THE FAR NORTHERN SECTIONS OF THE AREA. WE
ARE JUST GOING TO GET A GLANCING BLOW...SO HAVE KEPT POPS IN THE
SLIGHT CHANCE CATEGORY BOTH THURSDAY NIGHT AND FRIDAY. HIGHS
FRIDAY TO BE WARM AS WELL...IN THE LOW TO MID 80S.
FRIDAY NIGHT THROUGH SATURDAY TO BE ACTIVE WITH A FEW MORE
SHORTWAVE OVERTOPPING THE UPPER LEVEL RIDGE OVER THE ROCKIES...AND
A COLD FRONT DROPS THROUGH THE AREA FRIDAY NIGHT AND SATURDAY AS
WELL. HAVE SOME SLIGHT CHANCE AND CHANCE POPS GOING...WHICH MAY BE
RAISED AS DETAILS BECOME CLEAR. WARM TEMPERATURES ARE EXPECTED TO
CONTINUE. SATURDAY NIGHT SHOULD BE QUIET AND DRIER.
BEGINNING SUNDAY UNCERTAINTY INCREASES OVER THE AREA WITH THE
UPPER LEVEL RIDGE FLATTENING AND SHIFTING EAST...ALLOWING A
FAIRLY STRONG SHORTWAVE TO MOVE ACROSS THE AREA IN THE TUESDAY-
WEDNESDAY TIME RANGE. MODELS HAVE VARYING SOLUTIONS...BUT
GENERALLY TEMPERATURES COOL OFF BACK TOWARDS NORMAL VALUES
AGAIN...WITH PRECIPITATION CHANCES BEGINNING SUNDAY AND CONTINUING
THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1233 AM CDT WED SEP 4 2013
WEAK SFC FRONT WILL BE CROSSING THE REGION EARLY TONIGHT FROM
NORTH TO SOUTH AND ALLOWING WINDS TO SHIFT TO THE NORTH AND BECOME
AROUND 3-5 KTS STRONGER. COULD SEE A VERY BRIEF PERIOD OF LLWS
ALONG THE FRONT AT DLH AND HYR UNTIL AROUND 08/09Z. CLOUDS WILL
ALSO INCREASE ALONG THE FRONT...MAINLY STAYING VFR...WITH THE
EXCEPTION OF AROUND HIB...DLH AND HYR WHERE A PERIOD OF MVFR CIGS
ARE POSSIBLE DUE TO WEAK LAKE ENHANCEMENT AS NORTH WINDS PUSH
INLAND FROM LS. HIGH PRESSURE WILL BUILD IN QUICKLY WED
AFTERNOON/EVENING AND ALLOW SKIES TO CLEAR OUT AND WINDS TO BECOME
CALM.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ121-
144>148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS ELKO NV
1046 AM PDT WED SEP 4 2013
.SYNOPSIS...YET ANOTHER ROUND OF THUNDERSTORMS ON TAP ACROSS
NEVADA TODAY AND TONIGHT. MANY STORMS WILL AGAIN PRODUCE VERY
HEAVY RAINFALL...AND A FLASH FLOOD WATCH IS NOW IN EFFECT THROUGH
EARLY THURSDAY MORNING. DRIER AIR AND STRONGER WINDS WILL PUSH
INTO NORTHWESTERN NEVADA ON THURSDAY. THUNDERSTORM CHANCES WILL
SLOWLY DECREASE ACROSS EASTERN NEVADA THROUGH SATURDAY.
&&
.FIRE WEATHER UPDATE...ISSUED A RED FLAG WARNING FOR GUSTY WINDS
AND LOW RELATIVE HUMIDITY FOR ZONE 467 IN NORTHWEST NEVADA...WHICH
WILL BE IN EFFECT ON THURSDAY BETWEEN 1 PM AND 9 PM PDT. NO OTHER
CHANGES AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED AT 810 AM /
SYNOPSIS...YET ANOTHER ROUND OF THUNDERSTORMS ON TAP ACROSS
NEVADA TODAY AND TONIGHT. MANY STORMS WILL AGAIN PRODUCE VERY
HEAVY RAINFALL...AND A FLASH FLOOD WATCH IS NOW IN EFFECT THROUGH
EARLY THURSDAY MORNING. THUNDERSTORM CHANCES WILL SLOWLY DECREASE
ACROSS EASTERN NEVADA THROUGH SATURDAY.
UPDATE...SENT OUT AN UPDATED FORECAST TO INCREASE THUNDERSTORM
COVERAGE THIS AFTERNOON AND THIS EVENING, TO THE LIKELY/NUMEROUS
CATEGORY IN MANY CASES. 12Z NAM AND THE 3-KM HRRR ARE FORECASTING
ANOTHER BUSY AFTERNOON AND EVENING, WITH STORMS REDEVELOPING AGAIN
AROUND NOON. THIS MORNING`S ELKO SOUNDING IS STILL VERY MOIST WITH
PRECIPITABLE WATER NEAR 1 INCH, WITH A CONVECTIVE TEMPERATURE OF
ONLY 80 DEGREES. STORM MOTION AGAIN TODAY WILL BE TO THE NORTHEAST
AT 10-20 MPH, BUT SO FAR THAT HAS DONE LITTLE TO HINDER THE FLASH
FLOODING THREAT THE PAST FEW DAYS. CONVECTION WILL CONTINUE PAST
5 PM, WITH SOME STORMS LASTING ALL NIGHT AGAIN, SO EXTENDED THE
FLASH FLOOD WATCH THROUGH 5 AM THURSDAY MORNING. SHEAR DOES
INCREASE SOME ACROSS MAINLY NORTHERN NEVADA, IN ASSOCIATION WITH
CLOSED LOW WEST OF OREGON, SO ALSO EXPECTING A FEW SEVERE STORMS
THIS AFTERNOON, ESPECIALLY NEAR THE OREGON/IDAHO BORDERS. TURNER
PREV DISCUSSION... /ISSUED AT 316 AM /
SYNOPSIS...AS A LOW PRESSURE SYSTEM SLOWLY APPROACHES FROM OFF
THE PACIFIC COAST...ENOUGH MOISTURE WILL BE AVAILABLE TO TRIGGER
THUNDERSTORMS ALL ACROSS THE SILVER STATE AGAIN TODAY. UNSETTLED
WEATHER WILL CONTINUE ACROSS EASTERN NEVADA THROUGH SATURDAY.
SHORT TERM...TODAY THROUGH THURSDAY. A COUPLE VERY STRONG
THUNDERSTORM CELLS LINGERED PAST MIDNIGHT...IN WHITE PINE COUNTY
AND NORTHERN ELKO COUNTY. STILL A LIGHTNING STRIKE OR TWO
OCCURRING AT 3 AM PDT...EVEN IN HUMBOLDT COUNTY AS A COUPLE
UNDETECTABLE SHORTWAVES CUT THROUGH THE WEST. THE GFS MODEL SHOWS
THE TAIL END OF A COUPLE 250 MB JET STREAKS MERGING OVER CENTRAL
NEVADA BY 12Z THIS MORNING AND INSTABILITY SHOULD THEREAFTER SHUT
DOWN UNTIL HEATING INSTIGATES MORE CONVECTION LATER THIS MORNING.
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE SYNOPTIC PATTERN. A
PACIFIC LOW PRESSURE SYSTEM WILL SLOWLY MOVE ONSHORE OVER OREGON
BY THURSDAY. HIGH PRESSURE WILL HOLD POSITION OVER COLORADO AND
KANSAS HOWEVER THE INCOMING UPPER LOW WILL EFFECTIVELY SHUNT THE
MOIST FLOW ORIGINATING NEAR THE BAJA REGION.
THERE IS SOME MODEL DISCREPANCY ON PRECIPITABLE WATER AMOUNTS
TODAY HOWEVER THERE SHOULD BE PLENTY RESIDUAL MOISTURE AVAILABLE TO
ALLOW DEVELOPMENT OF SOME MORE HEAVY RAIN PRODUCING THUNDERSTORMS.
THE FLASH FLOOD WATCH HAS BEEN EXTENDED THROUGH THIS AFTERNOON
FOR PARTS OF NORTHERN AND CENTRAL NEVADA. THE DRY UPPER LOW WILL
SHOVE THE MOIST FLOW EAST BY THURSDAY. THE PRESSURE GRADIENT WILL
TIGHTEN AND BREEZY WINDS ARE EXPECTED FOR THURSDAY AFTERNOON.
LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY. THE FORECAST
PERIOD COMMENCES WITH A CLOSED UPPER LOW AND A POSITIVE TILT TROF
MOVING INTO THE WEST...DISPLACING THE RIDGE INTO THE CENTRAL
PLAINS. THE NCEP AND NON-NCEP MODELS ARE IN DESCENT AGREEMENT
THROUGH THE PERIOD. AS TIME ELAPSES...THE UPPER TROF WILL NUDGE
THE RIDGE EASTWARD...AND THIS PROGRESSION WILL EFFECTIVELY CUT OF
THE MONSOONAL FLOW...USHERING...A DRY AIRMASS INTO THE SILVER
STATE. ALTHOUGH...WITH PWS HOVERING AROUND .75 OF AN INCH ALONG
THE UTAH/NV BORDER...KEPT SLIGHT CHANCE POPS OVER ELKO AND WHITE
PINE COUNTIES. BY THE WEEKEND...THE MODELS START TO BECOME
SLIGHTLY OUT OF PHASE...BUT GENERALLY DEPICT WIDESPREAD NORTHWEST
DRY FLOW OVER THE CWA ON SUNDAY...MONDAY...AND TUESDAY. SENSIBLE
WEATHER-WISE EXPECT SLIGHTLY COOLER TEMPERATURES AND MOSTLY CLEAR
SKIES.
AVIATION...VFR CONDITIONS ARE EXPECTED AT KWMC KEKO...KELY AND KTPH.
HOWEVER...MONSOON MOISTURE WILL CONTINUE TO PRODUCE SHOWERS AND
THUNDERSTORMS AGAIN TODAY...WILL KEEP VC TS IN TAFS. IF THE STORMS
MOVE NEAR THE TERMINAL EXPECT...FLOODING RAINS...GUSTY WINDS...TURBULENCE
AND SMALL HAIL. THE TURBULENCE GUIDANCE FROM THE AVIATION WEATHER
CENTER SUGGESTS THAT ANY NON-CONVECTIVE TURBULENCE OVER THE REGION
WOULD BE LIGHT. OFTEN MONSOON AIR MASSES ARE SLOW TO CLEAR
OUT...EXPECTING TS OVER EASTERN NV ON THURSDAY...POTENTIALLY
IMPACTING KEKO AND KELY.
FIRE WEATHER...SHOWERS AND THUNDERSTORMS WITH WETTING RAINS WILL
DEVELOP AGAIN TODAY AND FLASH FLOODING OR DEBRIS FLOWS WILL BE A
POSSIBILITY IN SOME AREAS. A DRYING TREND IS EXPECTED BEGINNING
THURSDAY WITH THUNDERSTORMS MAINLY AFFECTING EASTERN NEVADA
THROUGH SATURDAY. BREEZY WINDS WILL DEVELOP ON THURSDAY AND
FRIDAY WITH GUSTS NEAR 30 MPH...HOWEVER HUMIDITY LEVELS ARE EXPECTED
TO BE ABOVE 15 PERCENT WHERE WINDS WILL BE STRONGEST.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NORTHERN ELKO
COUNTY...NORTHERN LANDER COUNTY AND NORTHERN EUREKA COUNTY...
RUBY MOUNTAINS/EAST HUMBOLDT RANGE...SOUTH CENTRAL ELKO COUNTY...
SOUTHEASTERN ELKO COUNTY...SOUTHERN LANDER COUNTY AND SOUTHERN
EUREKA COUNTY...SOUTHWESTERN ELKO COUNTY...WHITE PINE COUNTY.
RED FLAG WARNING FROM 1 PM TO 9 PM PDT THURSDAY FOR HUMBOLDT
COUNTY.
&&
$$
96
AREA FORECAST DISCUSSION
NWS ELKO NV
810 AM PDT WED SEP 4 2013
.SYNOPSIS...YET ANOTHER ROUND OF THUNDERSTORMS ON TAP ACROSS
NEVADA TODAY AND TONIGHT. MANY STORMS WILL AGAIN PRODUCE VERY
HEAVY RAINFALL...AND A FLASH FLOOD WATCH IS NOW IN EFFECT THROUGH
EARLY THURSDAY MORNING. THUNDERSTORM CHANCES WILL SLOWLY DECREASE
ACROSS EASTERN NEVADA THROUGH SATURDAY.
&&
.UPDATE...SENT OUT AN UPDATED FORECAST TO INCREASE THUNDERSTORM
COVERAGE THIS AFTERNOON AND THIS EVENING, TO THE LIKELY/NUMEROUS
CATEGORY IN MANY CASES. 12Z NAM AND THE 3-KM HRRR ARE FORECASTING
ANOTHER BUSY AFTERNOON AND EVENING, WITH STORMS REDEVELOPING AGAIN
AROUND NOON. THIS MORNING`S ELKO SOUNDING IS STILL VERY MOIST WITH
PRECIPITABLE WATER NEAR 1 INCH, WITH A CONVECTIVE TEMPERATURE OF
ONLY 80 DEGREES. STORM MOTION AGAIN TODAY WILL BE TO THE NORTHEAST
AT 10-20 MPH, BUT SO FAR THAT HAS DONE LITTLE TO HINDER THE FLASH
FLOODING THREAT THE PAST FEW DAYS. CONVECTION WILL CONTINUE PAST
5 PM, WITH SOME STORMS LASTING ALL NIGHT AGAIN, SO EXTENDED THE
FLASH FLOOD WATCH THROUGH 5 AM THURSDAY MORNING. SHEAR DOES
INCREASE SOME ACROSS MAINLY NORTHERN NEVADA, IN ASSOCIATION WITH
CLOSED LOW WEST OF OREGON, SO ALSO EXPECTING A FEW SEVERE STORMS
THIS AFTERNOON, ESPECIALLY NEAR THE OREGON/IDAHO BORDERS. TURNER
&&
.PREV DISCUSSION... /ISSUED AT 316 AM /
SYNOPSIS...AS A LOW PRESSURE SYSTEM SLOWLY APPROACHES FROM OFF
THE PACIFIC COAST...ENOUGH MOISTURE WILL BE AVAILABLE TO TRIGGER
THUNDERSTORMS ALL ACROSS THE SILVER STATE AGAIN TODAY. UNSETTLED
WEATHER WILL CONTINUE ACROSS EASTERN NEVADA THROUGH SATURDAY.
SHORT TERM...TODAY THROUGH THURSDAY. A COUPLE VERY STRONG
THUNDERSTORM CELLS LINGERED PAST MIDNIGHT...IN WHITE PINE COUNTY
AND NORTHERN ELKO COUNTY. STILL A LIGHTNING STRIKE OR TWO
OCCURRING AT 3 AM PDT...EVEN IN HUMBOLDT COUNTY AS A COUPLE
UNDETECTABLE SHORTWAVES CUT THROUGH THE WEST. THE GFS MODEL SHOWS
THE TAIL END OF A COUPLE 250 MB JET STREAKS MERGING OVER CENTRAL
NEVADA BY 12Z THIS MORNING AND INSTABILITY SHOULD THEREAFTER SHUT
DOWN UNTIL HEATING INSTIGATES MORE CONVECTION LATER THIS MORNING.
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE SYNOPTIC PATTERN. A
PACIFIC LOW PRESSURE SYSTEM WILL SLOWLY MOVE ONSHORE OVER OREGON
BY THURSDAY. HIGH PRESSURE WILL HOLD POSITION OVER COLORADO AND
KANSAS HOWEVER THE INCOMING UPPER LOW WILL EFFECTIVELY SHUNT THE
MOIST FLOW ORIGINATING NEAR THE BAJA REGION.
THERE IS SOME MODEL DISCREPANCY ON PRECIPITABLE WATER AMOUNTS
TODAY HOWEVER THERE SHOULD BE PLENTY RESIDUAL MOISTURE AVAILABLE TO
ALLOW DEVELOPMENT OF SOME MORE HEAVY RAIN PRODUCING THUNDERSTORMS.
THE FLASH FLOOD WATCH HAS BEEN EXTENDED THROUGH THIS AFTERNOON
FOR PARTS OF NORTHERN AND CENTRAL NEVADA. THE DRY UPPER LOW WILL
SHOVE THE MOIST FLOW EAST BY THURSDAY. THE PRESSURE GRADIENT WILL
TIGHTEN AND BREEZY WINDS ARE EXPECTED FOR THURSDAY AFTERNOON.
LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY. THE FORECAST
PERIOD COMMENCES WITH A CLOSED UPPER LOW AND A POSITIVE TILT TROF
MOVING INTO THE WEST...DISPLACING THE RIDGE INTO THE CENTRAL
PLAINS. THE NCEP AND NON-NCEP MODELS ARE IN DESCENT AGREEMENT
THROUGH THE PERIOD. AS TIME ELAPSES...THE UPPER TROF WILL NUDGE
THE RIDGE EASTWARD...AND THIS PROGRESSION WILL EFFECTIVELY CUT OF
THE MONSOONAL FLOW...USHERING...A DRY AIRMASS INTO THE SILVER
STATE. ALTHOUGH...WITH PWS HOVERING AROUND .75 OF AN INCH ALONG
THE UTAH/NV BORDER...KEPT SLIGHT CHANCE POPS OVER ELKO AND WHITE
PINE COUNTIES. BY THE WEEKEND...THE MODELS START TO BECOME
SLIGHTLY OUT OF PHASE...BUT GENERALLY DEPICT WIDESPREAD NORTHWEST
DRY FLOW OVER THE CWA ON SUNDAY...MONDAY...AND TUESDAY. SENSIBLE
WEATHER-WISE EXPECT SLIGHTLY COOLER TEMPERATURES AND MOSTLY CLEAR
SKIES.
AVIATION...VFR CONDITIONS ARE EXPECTED AT KWMC KEKO...KELY AND KTPH.
HOWEVER...MONSOON MOISTURE WILL CONTINUE TO PRODUCE SHOWERS AND
THUNDERSTORMS AGAIN TODAY...WILL KEEP VC TS IN TAFS. IF THE STORMS
MOVE NEAR THE TERMINAL EXPECT...FLOODING RAINS...GUSTY WINDS...TURBULENCE
AND SMALL HAIL. THE TURBULENCE GUIDANCE FROM THE AVIATION WEATHER
CENTER SUGGESTS THAT ANY NON-CONVECTIVE TURBULENCE OVER THE REGION
WOULD BE LIGHT. OFTEN MONSOON AIR MASSES ARE SLOW TO CLEAR
OUT...EXPECTING TS OVER EASTERN NV ON THURSDAY...POTENTIALLY
IMPACTING KEKO AND KELY.
FIRE WEATHER...SHOWERS AND THUNDERSTORMS WITH WETTING RAINS WILL
DEVELOP AGAIN TODAY AND FLASH FLOODING OR DEBRIS FLOWS WILL BE A
POSSIBILITY IN SOME AREAS. A DRYING TREND IS EXPECTED BEGINNING
THURSDAY WITH THUNDERSTORMS MAINLY AFFECTING EASTERN NEVADA
THROUGH SATURDAY. BREEZY WINDS WILL DEVELOP ON THURSDAY AND
FRIDAY WITH GUSTS NEAR 30 MPH...HOWEVER HUMIDITY LEVELS ARE EXPECTED
TO BE ABOVE 15 PERCENT WHERE WINDS WILL BE STRONGEST.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NORTHERN ELKO
COUNTY...NORTHERN LANDER COUNTY AND NORTHERN EUREKA COUNTY...
RUBY MOUNTAINS/EAST HUMBOLDT RANGE...SOUTH CENTRAL ELKO COUNTY...
SOUTHEASTERN ELKO COUNTY...SOUTHERN LANDER COUNTY AND SOUTHERN
EUREKA COUNTY...SOUTHWESTERN ELKO COUNTY...WHITE PINE COUNTY.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 PM EDT WED SEP 4 2013
.SYNOPSIS...
DRIER AIR WILL BUILD OVER THE AREA TODAY IN WAKE OF A WEAK COLD
FRONT. CANADIAN HIGH PRESSURE WILL BRING A REINFORCEMENT OF DRY
AND SLIGHTLY COOLER AIR FRIDAY INTO SATURDAY. A WARMING TREND IN
EXPECTED EARLY NEXT WEEK AS AN UPPER RIDGE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...DRIER AIR IN WAKE OF A COLD FRONT HAS
ERADICATED THE WRETCHED QUALITY OF THE MUGGY AIR MASS WHICH HAS
RECENTLY BLANKETED THE AREA. DEWPOINTS WERE DROPPING IN THE 60S
AS DRIER AIR AND MIXING WERE GETTING UNDERWAY THIS MORNING. THE
FRONT ITSELF WAS LOSING IDENTITY OFFSHORE NEARING THE GULF-STREAM
AND WAS CURLED BACK TOWARD THE SW SOUTH OF WINYAH BAY AND YAWKEY
SOUTH ISLAND RESERVE. HIGH RESOLUTION NEAR TERM MODELS WRF NSSL
AND THE HRRR DEPICT SIMILAR SOLUTIONS...ISOLATED SHOWERS FAVORED
OVER OUR SOUTHERN COASTAL INTERIOR ZONES WHERE HIGH MOISTURE
CONTENT PREVAILS. AFTERNOON SEA BREEZE CONVERGENCE WILL ALLOW A
FEW MODERATE CUMULUS BUILD UPS. UPPER LEVEL MOISTURE REMAINS
SPARSE SO ONLY SHOWERS ARE ADVERTISED VERSUS TSTMS. THE BEST
CHANCE OF A SHOWER WILL BE BETWEEN 2PM-6PM. DIURNAL COOLING
SHOULD QUICKLY DIMINISH CONVECTION INTO EARLY EVENING. LOWS
TONIGHT UNDER CLEAR SKIES MAINLY MIDDLE AND UPPER 60S WITH
LOWER 70S ALONG THE COAST IN A LIGHT SOUTHERLY WIND FLOW.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT STALLED NOT TO FAR OFFSHORE BUT A
SECONDARY AXIS OF WEAK CONVERGENCE DEVELOPS ALONG THE COASTAL PLAIN
IN ASSOCIATION WITH A SURFACE TROUGH. FORECAST SOUNDINGS SHOW VERY
DRY MID LEVELS AND SO MEASURABLE PRECIPITATION SEEMS QUITE UNLIKELY
BUT A SLIGHT CHANCE WILL BE CARRIED ALONG COASTAL ZONES IN THE EVENT
OF A STRAY 0.01". WHAT LITTLE CAA BEHIND THE BOUNDARY THERE HAD
BEEN ON WED WILL BE GONE BY THURS AND TEMPS TO BE BACK A FEW DEGREES
ABOVE CLIMO. MORE APPRECIABLE FRONT TO COME THROUGH EITHER THURSDAY
NIGHT OR FRIDAY MORNING DEPENDING ON MODEL CHOICE. GIVEN THE STRONG
SURFACE PRESSURE ADVECTION PUSHING IT PREFER THE QUICKER TIMING I.E.
WRF. FRIDAY HIGHS KNOCKED BACK DOWN A FEW DEGREES BELOW CLIMO AND
DEWPOINTS TO FALL INTO THE MID OR EVEN LOW 60S...THE LATTER MOST
LIKELY OVER NW ZONES. FAR SRN SC ZONES MAY HOLD ON TO DEWPOINTS IN
THE UPPER 60S. INTERESTING SKY COVER FORECAST LATE FRIDAY INTO
FRIDAY NIGHT AS GUIDANCE SHOWING SOME ATLANTIC MOISTURE ASSOC WITH
THE NE SURGE. MID LEVELS REMAIN VERY DRY...PROBABLY DRIER THAN FCST
SOUNDINGS SHOW IN THE CONTINUED NW FLOW...AND WITH NO NOTICEABLE
FRONTAL INVERSION THIS MOISTURE MAY NOT GET TRAPPED AS MUCH AS THE
RELATIVELY CLOUDY GUIDANCE IMPLIES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 AM WEDNESDAY...VERY QUIET WEATHER ON TAP FOR THE PERIOD.
UPPER RIDGE REMAINS ACROSS THE PLAINS THROUGH SUNDAY OR MONDAY WHILE
SURFACE HIGH CONTINUES TO BUILD IN FROM THE NORTH. MONDAY INTO
TUESDAY WILL BRING THE UPPER RIDGE EASTWARD IN A WEAKENING STATE.
THE SURFACE HIGH WILL SHIFT SLIGHTLY EASTWARD AS WELL BUT NOT ENOUGH
FOR SUFFICIENT MOISTURE FLUX LOCALLY. TEMPERATURES NEAR CLIMO EARLY
IN THE PERIOD WITH JUST A VERY SLOW RISE THROUGHOUT AS A RESULT OF
SOLAR MODERATION AS OPPOSED TO ANY THERMAL ADVECTION.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...MODELS STILL ADVERTISING ISOLATED LIGHT SHOWERS MAINLY
ALONG THE RESULTANT SEA BREEZE BOUNDARY THIS AFTERNOON. BEST
CHANCE WILL BE OVER THE SOUTHERN THIRD OF THE CWA WHERE THE BEST
PWATS RESIDE. WINDS WILL BE EASTERLY FOR THE MOST PART THIS
AFTERNOON...STRONGEST NEAR THE COAST. TONIGHT...GOOD RADIATIONAL
COOLING CONDITIONS WILL BRING IN THE CHANCE FOR FOG AFTER 08Z.
INLAND TERMINALS STAND THE BEST CHANCE FOR POTENTIAL IFR
CONDITIONS. THURSDAY...NICE AVIATION DAY WITH FOG BURNING OFF
EARLY WITH SCATTERED TO NEARLY CLEAR SKIES AND LIGHT WINDS.
EXTENDED OUTLOOK...MORNING FOG/STRATUS IS POSSIBLE THROUGH THE
EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS FRIDAY AND MONDAY WITH
WEAK BACKDOOR COLD FRONTS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...WEAK COLD FRONT HAS MOVED SOUTH AND EAST
OF THE OF THE WATERS THIS MORNING AND WILL BE FOLLOWED BY WEAK
OFFSHORE FLOW. DIFFUSE GRADIENT BEHIND THE FRONT WILL ALLOW
DEVELOPMENT OF AFTERNOON SEA BREEZE. THIS WILL LEAD TO STRONGEST
WINDS OVER THE NEAR SHORE WATERS WITH LIGHTER WINDS AWAY FROM
SHORE. SPEEDS WILL STRUGGLE TO EXCEED 10 KT BUT ISOLATED GUSTS IN
THE AFTERNOON TO 15 KT WILL BE POSSIBLE. DISSIPATION OF SEA BREEZE
CIRCULATION THIS EVENING WILL RESULT IN WINDS BECOMING LIGHT AND
VARIABLE OVERNIGHT. SEAS WILL RUN 2 TO 3 FT THROUGH THE PERIOD.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...EVEN THOUGH A FRONT WILL BE STALLED AND
WEAKENING NOT FAR TO THE SOUTH ON THURSDAY THE FLOW WILL TURN BACK
AROUND TO A SOUTHERLY DIRECTION AS SURFACE TROUGHINESS DEVELOPS JUST
INLAND FROM THE COAST. IT WILL BE A VERY LIGHT FLOW WITH SPEEDS
GENERALLY CAPPED AT 10KT RESULTING IN 2 FT SEAS. A FAIRLY QUICK VEER
TO THE NORTH IS SLATED FOR THURSDAY NIGHT ALTHOUGH SOME LESS FAVORED
MODEL SOLUTIONS ARE SLOWER. A RELATIVELY STRONG HIGH WILL BUILD IN
BEHIND THE THURSDAY NIGHT FRONT AND WIND SPEEDS MAY INCREASE A
CATEGORY OR MORE BUILDING SEAS INTO THE 2 TO 4 FT RANGE...A LITTLE
LOWER OVER SRN ZONES.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...ANY RESIDUAL VESTIGE OF THE SURGE FROM THE
SHORT TERM SHOULD QUICKLY ABATE AS SATURDAY WEARS ON AS HIGH
PRESSURE BECOMES CENTERED OFF OF NEW ENGLAND/MID ATLANTIC AND
EXTENDS RIDGE AXIS INTO THE CAROLINAS. WINDS WILL BE ONSHORE EITHER
E OR NE AND FALL TO 10 KTS ALLOWING SEAS TO SETTLE TO 2 FT. A PIECE
OF THE HIGH BREAKS OFF AND STAYS BEHIND ACROSS THE CAROLINAS ON
SUNDAY CONTINUING THE TREND OF VERY LIGHT ONSHORE WIND AND SEAS
CAPPED AT 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL/8
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1231 PM EDT WED SEP 4 2013
.SYNOPSIS...
DRIER AIR WILL BUILD OVER THE AREA TODAY IN WAKE OF A WEAK COLD
FRONT. CANADIAN HIGH PRESSURE WILL BRING A REINFORCEMENT OF DRY
AND SLIGHTLY COOLER AIR FRIDAY INTO SATURDAY. A WARMING TREND IN
EXPECTED EARLY NEXT WEEK AS AN UPPER RIDGE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...DRIER AIR IN WAKE OF A COLD FRONT HAS
ERADICATED THE WRETCHED QUALITY OF THE MUGGY AIR MASS WHICH HAS
RECENTLY BLANKETED THE AREA. DEWPOINTS WERE DROPPING IN THE 60S
AS DRIER AIR AND MIXING WERE GETTING UNDERWAY THIS MORNING. THE
FRONT ITSELF WAS LOSING IDENTITY OFFSHORE NEARING THE GULF-STREAM
AND WAS CURLED BACK TOWARD THE SW SOUTH OF WINYAH BAY AND YAWKEY
SOUTH ISLAND RESERVE. HIGH RESOLUTION NEAR TERM MODELS WRF NSSL
AND THE HRRR DEPICT SIMILAR SOLUTIONS...ISOLATED SHOWERS FAVORED
OVER OUR SOUTHERN COASTAL INTERIOR ZONES WHERE HIGH MOISTURE
CONTENT PREVAILS. AFTERNOON SEA BREEZE CONVERGENCE WILL ALLOW A
FEW MODERATE CUMULUS BUILD UPS. UPPER LEVEL MOISTURE REMAINS
SPARSE SO ONLY SHOWERS ARE ADVERTISED VERSUS TSTMS. THE BEST
CHANCE OF A SHOWER WILL BE BETWEEN 2PM-6PM. DIURNAL COOLING
SHOULD QUICKLY DIMINISH CONVECTION INTO EARLY EVENING. LOWS
TONIGHT UNDER CLEAR SKIES MAINLY MIDDLE AND UPPER 60S WITH
LOWER 70S ALONG THE COAST IN A LIGHT SOUTHERLY WIND FLOW.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT STALLED NOT TO FAR OFFSHORE BUT A
SECONDARY AXIS OF WEAK CONVERGENCE DEVELOPS ALONG THE COASTAL PLAIN
IN ASSOCIATION WITH A SURFACE TROUGH. FORECAST SOUNDINGS SHOW VERY
DRY MID LEVELS AND SO MEASURABLE PRECIPITATION SEEMS QUITE UNLIKELY
BUT A SLIGHT CHANCE WILL BE CARRIED ALONG COASTAL ZONES IN THE EVENT
OF A STRAY 0.01". WHAT LITTLE CAA BEHIND THE BOUNDARY THERE HAD
BEEN ON WED WILL BE GONE BY THURS AND TEMPS TO BE BACK A FEW DEGREES
ABOVE CLIMO. MORE APPRECIABLE FRONT TO COME THROUGH EITHER THURSDAY
NIGHT OR FRIDAY MORNING DEPENDING ON MODEL CHOICE. GIVEN THE STRONG
SURFACE PRESSURE ADVECTION PUSHING IT PREFER THE QUICKER TIMING I.E.
WRF. FRIDAY HIGHS KNOCKED BACK DOWN A FEW DEGREES BELOW CLIMO AND
DEWPOINTS TO FALL INTO THE MID OR EVEN LOW 60S...THE LATTER MOST
LIKELY OVER NW ZONES. FAR SRN SC ZONES MAY HOLD ON TO DEWPOINTS IN
THE UPPER 60S. INTERESTING SKY COVER FORECAST LATE FRIDAY INTO
FRIDAY NIGHT AS GUIDANCE SHOWING SOME ATLANTIC MOISTURE ASSOC WITH
THE NE SURGE. MID LEVELS REMAIN VERY DRY...PROBABLY DRIER THAN FCST
SOUNDINGS SHOW IN THE CONTINUED NW FLOW...AND WITH NO NOTICEABLE
FRONTAL INVERSION THIS MOISTURE MAY NOT GET TRAPPED AS MUCH AS THE
RELATIVELY CLOUDY GUIDANCE IMPLIES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...VERY QUIET WEATHER ON TAP FOR THE PERIOD.
UPPER RIDGE REMAINS ACROSS THE PLAINS THROUGH SUNDAY OR MONDAY WHILE
SURFACE HIGH CONTINUES TO BUILD IN FROM THE NORTH. MONDAY INTO
TUESDAY WILL BRING THE UPPER RIDGE EASTWARD IN A WEAKENING STATE.
THE SURFACE HIGH WILL SHIFT SLIGHTLY EASTWARD AS WELL BUT NOT ENOUGH
FOR SUFFICIENT MOISTURE FLUX LOCALLY. TEMPERATURES NEAR CLIMO EARLY
IN THE PERIOD WITH JUST A VERY SLOW RISE THROUGHOUT AS A RESULT OF
SOLAR MODERATION AS OPPOSED TO ANY THERMAL ADVECTION.
&&
.AVIATION /12Z WEDNESDAY THROUGH MONDAY/...
AS OF 12Z...FRONT IS LINGERING OVER THE SOUTHERN PORTION OF THE
CWA. PWATS HAVE COME DOWN...BUT ARE STILL RANGING IN THE 1.5-1.9"
RANGE. SHOULD SEE SOME ISOLATED CONVECTION NEAR THE MYRTLES AROUND
MAX HEATING. WINDS WILL BE PREDOMINATELY NORTHEAST OVER THE
NORTHERN PORTION OF THE CWA...AND VARIABLE OVER THE SOUTHERN
PORTION. THE COAST WILL LIKELY SEE A SEA BREEZE RESULTANT BY
18-19Z. TONIGHT...GOOD RADIATIONAL COOLING CONDITIONS WILL BRING
IN THE CHANCE FOR FOG AFTER 08Z. INLAND TERMINALS STAND THE BEST
CHANCE FOR IFR CONDITIONS.
EXTENDED OUTLOOK...MORNING FOG/STRATUS IS POSSIBLE THROUGH THE
EXTENDED PERIOD. OTHERWISE VFR CONDITIONS SHOULD PREVAIL.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...WEAK COLD FRONT HAS MOVED SOUTH AND EAST
OF THE OF THE WATERS THIS MORNING AND WILL BE FOLLOWED BY WEAK
OFFSHORE FLOW. DIFFUSE GRADIENT BEHIND THE FRONT WILL ALLOW
DEVELOPMENT OF AFTERNOON SEA BREEZE. THIS WILL LEAD TO STRONGEST
WINDS OVER THE NEAR SHORE WATERS WITH LIGHTER WINDS AWAY FROM
SHORE. SPEEDS WILL STRUGGLE TO EXCEED 10 KT BUT ISOLATED GUSTS IN
THE AFTERNOON TO 15 KT WILL BE POSSIBLE. DISSIPATION OF SEA BREEZE
CIRCULATION THIS EVENING WILL RESULT IN WINDS BECOMING LIGHT AND
VARIABLE OVERNIGHT. SEAS WILL RUN 2 TO 3 FT THROUGH THE PERIOD.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...EVEN THOUGH A FRONT WILL BE STALLED AND
WEAKENING NOT FAR TO THE SOUTH ON THURSDAY THE FLOW WILL TURN BACK
AROUND TO A SOUTHERLY DIRECTION AS SURFACE TROUGHINESS DEVELOPS JUST
INLAND FROM THE COAST. IT WILL BE A VERY LIGHT FLOW WITH SPEEDS
GENERALLY CAPPED AT 10KT RESULTING IN 2 FT SEAS. A FAIRLY QUICK VEER
TO THE NORTH IS SLATED FOR THURSDAY NIGHT ALTHOUGH SOME LESS FAVORED
MODEL SOLUTIONS ARE SLOWER. A RELATIVELY STRONG HIGH WILL BUILD IN
BEHIND THE THURSDAY NIGHT FRONT AND WIND SPEEDS MAY INCREASE A
CATEGORY OR MORE BUILDING SEAS INTO THE 2 TO 4 FT RANGE...A LITTLE
LOWER OVER SRN ZONES.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...ANY RESIDUAL VESTIGE OF THE SURGE FROM THE
SHORT TERM SHOULD QUICKLY ABATE AS SATURDAY WEARS ON AS HIGH
PRESSURE BECOMES CENTERED OFF OF NEW ENGLAND/MID ATLANTIC AND
EXTENDS RIDGE AXIS INTO THE CAROLINAS. WINDS WILL BE ONSHORE EITHER
E OR NE AND FALL TO 10 KTS ALLOWING SEAS TO SETTLE TO 2 FT. A PIECE
OF THE HIGH BREAKS OFF AND STAYS BEHIND ACROSS THE CAROLINAS ON
SUNDAY CONTINUING THE TREND OF VERY LIGHT ONSHORE WIND AND SEAS
CAPPED AT 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1007 AM EDT WED SEP 4 2013
.SYNOPSIS...
DRIER AIR WILL BUILD OVER THE AREA TODAY IN WAKE OF A WEAK COLD
FRONT. CANADIAN HIGH PRESSURE WILL BRING A REINFORCEMENT OF DRY
AND SLIGHTLY COOLER AIR FRIDAY INTO SATURDAY. A WARMING TREND IN
EXPECTED EARLY NEXT WEEK AS AN UPPER RIDGE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...DRIER AIR IN WAKE OF A COLD FRONT HAS
ERADICATED THE WRETCHED QUALITY OF THE MUGGY AIR MASS WHICH HAS
RECENTLY BLANKETED THE AREA. DEWPOINTS WERE DROPPING IN THE 60S
AS DRIER AIR AND MIXING WERE GETTING UNDERWAY THIS MORNING. THE
FRONT ITSELF WAS LOSING IDENTITY OFFSHORE NEARING THE GULF-STREAM
AND WAS CURLED BACK TOWARD THE SW SOUTH OF WINYAH BAY AND YAWKEY
SOUTH ISLAND RESERVE. HIGH RESOLUTION NEAR TERM MODELS WRF NSSL
AND THE HRRR DEPICT SIMILAR SOLUTIONS...ISOLATED SHOWERS FAVORED
OVER OUR SOUTHERN COASTAL INTERIOR ZONES WHERE HIGH MOISTURE
CONTENT PREVAILS. AFTERNOON SEA BREEZE CONVERGENCE WILL ALLOW A
FEW MODERATE CUMULUS BUILD UPS. UPPER LEVEL MOISTURE REMAINS
SPARSE SO ONLY SHOWERS ARE ADVERTISED VERSUS TSTMS. THE BEST
CHANCE OF A SHOWER WILL BE BETWEEN 2PM-6PM. DIURNAL COOLING
SHOULD QUICKLY DIMINISH CONVECTION INTO EARLY EVENING. LOWS
TONIGHT UNDER CLEAR SKIES MAINLY MIDDLE AND UPPER 60S WITH
LOWER 70S ALONG THE COAST IN A LIGHT SOUTHERLY WIND FLOW.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT STALLED NOT TO FAR OFFSHORE BUT A
SECONDARY AXIS OF WEAK CONVERGENCE DEVELOPS ALONG THE COASTAL PLAIN
IN ASSOCIATION WITH A SURFACE TROUGH. FORECAST SOUNDINGS SHOW VERY
DRY MID LEVELS AND SO MEASURABLE PRECIPITATION SEEMS QUITE UNLIKELY
BUT A SLIGHT CHANCE WILL BE CARRIED ALONG COASTAL ZONES IN THE EVENT
OF A STRAY 0.01". WHAT LITTLE CAA BEHIND THE BOUNDARY THERE HAD
BEEN ON WED WILL BE GONE BY THURS AND TEMPS TO BE BACK A FEW DEGREES
ABOVE CLIMO. MORE APPRECIABLE FRONT TO COME THROUGH EITHER THURSDAY
NIGHT OR FRIDAY MORNING DEPENDING ON MODEL CHOICE. GIVEN THE STRONG
SURFACE PRESSURE ADVECTION PUSHING IT PREFER THE QUICKER TIMING I.E.
WRF. FRIDAY HIGHS KNOCKED BACK DOWN A FEW DEGREES BELOW CLIMO AND
DEWPOINTS TO FALL INTO THE MID OR EVEN LOW 60S...THE LATTER MOST
LIKELY OVER NW ZONES. FAR SRN SC ZONES MAY HOLD ON TO DEWPOINTS IN
THE UPPER 60S. INTERESTING SKY COVER FORECAST LATE FRIDAY INTO
FRIDAY NIGHT AS GUIDANCE SHOWING SOME ATLANTIC MOISTURE ASSOC WITH
THE NE SURGE. MID LEVELS REMAIN VERY DRY...PROBABLY DRIER THAN FCST
SOUNDINGS SHOW IN THE CONTINUED NW FLOW...AND WITH NO NOTICEABLE
FRONTAL INVERSION THIS MOISTURE MAY NOT GET TRAPPED AS MUCH AS THE
RELATIVELY CLOUDY GUIDANCE IMPLIES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...VERY QUIET WEATHER ON TAP FOR THE PERIOD.
UPPER RIDGE REMAINS ACROSS THE PLAINS THROUGH SUNDAY OR MONDAY WHILE
SURFACE HIGH CONTINUES TO BUILD IN FROM THE NORTH. MONDAY INTO
TUESDAY WILL BRING THE UPPER RIDGE EASTWARD IN A WEAKENING STATE.
THE SURFACE HIGH WILL SHIFT SLIGHTLY EASTWARD AS WELL BUT NOT ENOUGH
FOR SUFFICIENT MOISTURE FLUX LOCALLY. TEMPERATURES NEAR CLIMO EARLY
IN THE PERIOD WITH JUST A VERY SLOW RISE THROUGHOUT AS A RESULT OF
SOLAR MODERATION AS OPPOSED TO ANY THERMAL ADVECTION.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 14Z...FRONT IS LINGERING OVER THE SOUTHERN PORTION OF THE
CWA. PWATS HAVE COME DOWN...BUT ARE STILL RANGING IN THE 1.5-1.9"
RANGE. SHOULD SEE SOME ISOLATED CONVECTION NEAR THE MYRTLES AROUND
MAX HEATING. WINDS WILL BE PREDOMINATELY NORTHEAST OVER THE
NORTHERN PORTION OF THE CWA...AND VARIABLE OVER THE SOUTHERN
PORTION. THE COAST WILL LIKELY SEE A SEA BREEZE RESULTANT BY
18-19Z. TONIGHT...GOOD RADIATIONAL COOLING CONDITIONS WILL BRING
IN THE CHANCE FOR FOG AFTER 08Z. INLAND TERMINALS STAND THE BEST
CHANCE FOR IFR CONDITIONS.
EXTENDED OUTLOOK...MORNING FOG/STRATUS IS POSSIBLE THROUGH THE
EXTENDED PERIOD. OTHERWISE VFR CONDITIONS SHOULD PREVAIL.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...WEAK COLD FRONT HAS MOVED SOUTH AND EAST
OF THE OF THE WATERS THIS MORNING AND WILL BE FOLLOWED BY WEAK
OFFSHORE FLOW. DIFFUSE GRADIENT BEHIND THE FRONT WILL ALLOW
DEVELOPMENT OF AFTERNOON SEA BREEZE. THIS WILL LEAD TO STRONGEST
WINDS OVER THE NEAR SHORE WATERS WITH LIGHTER WINDS AWAY FROM
SHORE. SPEEDS WILL STRUGGLE TO EXCEED 10 KT BUT ISOLATED GUSTS IN
THE AFTERNOON TO 15 KT WILL BE POSSIBLE. DISSIPATION OF SEA BREEZE
CIRCULATION THIS EVENING WILL RESULT IN WINDS BECOMING LIGHT AND
VARIABLE OVERNIGHT. SEAS WILL RUN 2 TO 3 FT THROUGH THE PERIOD.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...EVEN THOUGH A FRONT WILL BE STALLED AND
WEAKENING NOT FAR TO THE SOUTH ON THURSDAY THE FLOW WILL TURN BACK
AROUND TO A SOUTHERLY DIRECTION AS SURFACE TROUGHINESS DEVELOPS JUST
INLAND FROM THE COAST. IT WILL BE A VERY LIGHT FLOW WITH SPEEDS
GENERALLY CAPPED AT 10KT RESULTING IN 2 FT SEAS. A FAIRLY QUICK VEER
TO THE NORTH IS SLATED FOR THURSDAY NIGHT ALTHOUGH SOME LESS FAVORED
MODEL SOLUTIONS ARE SLOWER. A RELATIVELY STRONG HIGH WILL BUILD IN
BEHIND THE THURSDAY NIGHT FRONT AND WIND SPEEDS MAY INCREASE A
CATEGORY OR MORE BUILDING SEAS INTO THE 2 TO 4 FT RANGE...A LITTLE
LOWER OVER SRN ZONES.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...ANY RESIDUAL VESTIGE OF THE SURGE FROM THE
SHORT TERM SHOULD QUICKLY ABATE AS SATURDAY WEARS ON AS HIGH
PRESSURE BECOMES CENTERED OFF OF NEW ENGLAND/MID ATLANTIC AND
EXTENDS RIDGE AXIS INTO THE CAROLINAS. WINDS WILL BE ONSHORE EITHER
E OR NE AND FALL TO 10 KTS ALLOWING SEAS TO SETTLE TO 2 FT. A PIECE
OF THE HIGH BREAKS OFF AND STAYS BEHIND ACROSS THE CAROLINAS ON
SUNDAY CONTINUING THE TREND OF VERY LIGHT ONSHORE WIND AND SEAS
CAPPED AT 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...8
NEAR TERM...8
SHORT TERM...MBB
LONG TERM...MBB
MARINE...III/8/MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 AM EDT WED SEP 4 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST TODAY. A DRY
COLD FRONT WILL MOVE THROUGH THE REGION LATE THURSDAY AND THURSDAY
NIGHT... AND THEN STRONGER HIGH PRESSURE WILL BUILD INTO THE AREA
FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM WEDNESDAY...
LATEST SURFACE MAP AND SATELLITE IMAGERY SHOW THE PRIMARY COLD FRONT
(WIND SHIFT) LOCATED WELL SOUTH OF NC... ACROSS CENTRAL GA... WITH A
FEW SUBTLE SECONDARY BOUNDARIES DROPPING SOUTH AND SSW THROUGH NC.
ONE PRONOUNCED BOUNDARY APPEARS TO REPRESENT THE OUTFLOW FROM
EARLY-MORNING STORMS OVER SE VA... AND THIS BOUNDARY IS NOW TRACKING
SSW THROUGH THE SRN COASTAL PLAIN AND ERN SANDHILLS... WITH PATCHY
STRATOCUMULUS IN ITS WAKE OVER THE NORTH-CENTRAL AND NE CWA. DEW
POINTS HAVE DROPPED INTO THE 60-65 DEGREE RANGE OVER MUCH OF THE NRN
AND WRN CWA BUT REMAINS IN THE UPPER 60S TO LOWER 70S DOWN EAST...
AND IT IS IN THIS AREA OVER THE SOUTHEAST CWA WHERE MLCAPE IS
FORECAST TO PEAK NEAR 1500 J/KG. CONVECTION-ALLOWING MODELS DO
DEPICT SCATTERED CONVECTION OVER SOUTHEAST AND EXTREME SOUTH-CENTRAL
NC THIS AFTERNOON AND EVENING... REASONABLE GIVEN THE PRESENCE OF
ABUNDANT LOW LEVEL MOISTURE (DESPITE DRYING ALOFT NOTED ON WATER
VAPOR AND BLENDED TPW IMAGERY) AND MARGINAL 15-20 KTS OF BULK SHEAR.
THE HRRR SUGGESTS THAT WE`LL SEE AN INLAND-MOVING SEA BREEZE AS WELL
WHICH COULD PROVIDE AN ADDITIONAL FOCUS FOR LIFT. WILL INCLUDE A
VERY SMALL CHANCE OF A SHOWER OVER THE EXTREME SOUTHEAST... BUT
OTHERWISE EXPECT DRY WEATHER. THICKNESSES ARE EXPECTED TO STAY NEAR
NORMAL OVER MUCH OF THE AREA EXCEPT SLIGHTLY ABOVE NORMAL IN THE
SOUTHEAST... AND FORECAST HIGHS CLOSE TO NORMAL -- IN THE MID-UPPER
80S -- LOOK VERY REASONABLE. -GIH
MOSTLY CLEAR TONIGHT. LOWS IN THE LOWER 60S NW TO UPPER 60S SE. -BL
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 300 AM WEDNESDAY...
SHORTWAVE ENERGY DIVING SOUTHEASTWARD DOWN THE BACKSIDE OF THE UPPER
VORTEX OVER QUEBEC WILL SWING THROUGH THE NORTHEAST US AND SOUTHERN
NEW ENGLAND STATES ON THURSDAY/THURSDAY NIGHT. A SECONDARY SURGE OF
DRY-COOLER AIR WILL BEGIN TO SPREAD SOUTH AS SFC HIGH PRES OVER THE
GREAT LAKES BUILDS INTO THE MID-ATLANTIC STATES...REACHING CENTRAL
NC THURSDAY THURSDAY NIGHT/EARLY FRIDAY BY MEANS OF A DRY BACK-DOOR
COLD FRONTAL PASSAGE INTO THE AREA THURSDAY EVENING.
SEASONABLE HIGHS AHEAD OF THE FRONT THURSDAY AFTERNOON WITH
HIGHS IN THE MID 80S NORTH TO NEAR 90 SOUTH. LOWS IN THE LOWER 60S
NORTH TO MID 60S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 245 AM WEDNESDAY...
OVERALL THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MOSTLY DRY
CONDITIONS AS THE MAIN STORM TRACK REMAINS WELL NORTH OF THE REGION
AND SEVERAL ROUNDS OF SURFACE HIGH PRESSURE AND WEAK FLOW ALOFT
AROUND A BROAD TROUGH SITUATED ACROSS THE EASTERN CONUS DOMINATES
THE WEATHER ACROSS CENTRAL NC. ANOTHER REINFORCING SHOT OF STRONGER
SURFACE HIGH PRESSURE WILL BUILD OVER THE AREA FRIDAY INTO SATURDAY
BEHIND A FRONT WHICH IS PROGGED TO MOVE THROUGH THE REGION LATE
THURSDAY. WITH THIS RENEWED HIGH PRESSURE BUILDING IN...FRIDAY AND
SATURDAY ARE EXPECTED TO BE MOSTLY DRY.
THE HIGH IS THEN PROGGED TO SHIFT OFFSHORE BY LATE SATURDAY INTO
EARLY SUNDAY...BUT WITH ONLY MINIMAL MOISTURE RETURN...THE DRY
CONDITIONS ARE EXPECTED TO PERSIST. THEN...ANOTHER FRONT IS PROGGED
TO MOVE ACROSS THE AREA ON MONDAY...WITH YET ANOTHER RENEWED SURFACE
HIGH BUILDING INTO THE REGION FOR EARLY NEXT WEEK. FOR MONDAY...WILL
KEEP THE FORECAST DRY FOR NOW...BUT THERE COULD BE SOME ISOLATED
ACTIVITY...ESPECIALLY IF THE FRONT MOVES THROUGH DURING A FAVORABLE
TIME. IN ADDITION...WITH THE LATEST HIGH CENTERED SLIGHTLY FURTHER
TO THE NORTH THAN PREVIOUS ONES AND THEREFORE MORE IN THE WAY OF
EASTERLY FLOW...MOISTURE IS PROGGED TO GRADUALLY INCREASE THROUGH
EARLY NEXT WEEK. HOWEVER...THE EAST COAST TROUGH ALOFT IS FINALLY
EXPECTED TO BE REPLACED BY AN EASTWARD PROGRESSING UPPER LEVEL RIDGE
BY THE EARLY TO MIDDLE PART OF NEXT WEEK...WHICH MAY WORK AGAINST
ANY CONVECTIVE DEVELOPMENT. WITH ALL OF THIS IN MIND...WITH MAINTAIN
A DRY FORECAST THROUGH THE REMAINDER OF THE LONG TERM PERIOD...BUT
THAT IS NOT TO SAY THERE COULD BE SOME ISOLATED DIURNAL TYPE
ACTIVITY TO START NEXT WEEK. TEMPS WILL BE TIED TO THE MULTIPLE
FRONTAL PASSAGES DURING THE PERIOD...BUT WILL GENERALLY BE NEAR TO
SLIGHTLY BELOW NORMAL THROUGHOUT THE ENTIRE PERIOD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 700 AM WEDNESDAY...
24-HR TAF PERIOD:
PATCHY FOG IN THE EAST SHOULD LIFT AND MIX OUT SHORTLY AFTER
DAYBREAK. THEREAFTER WEAK SURFACE HIGH PRESSURE WILL BUILD INTO THE
AREA THROUGH THE AFTERNOON...SECURING DRY VFR CONDITIONS THROUGH THE
REMAINDER OF THE PERIOD. CLEAR SKIES TONIGHT COULD SUPPORT SUB-VFR
CONDITIONS IN FOG AND/OR STRATUS...MAINLY ACROSS EASTERN TERMINALS.
LOOKING AHEAD:
ASIDE FROM EARLY MORNING FOG/STRATUS...EXPECT VFR CONDITIONS
THROUGH SUNDAY AS HIGH PRESSURE BUILDS INTO THE REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL/GIH
NEAR TERM...HARTFIELD/CBL
SHORT TERM...CBL
LONG TERM...KRR
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
645 AM EDT WED SEP 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE OHIO VALLEY TODAY. ON
THURSDAY...A MOISTURE-STARVED COLD FRONT WILL MOVE SOUTH THROUGH THE
REGION...PRODUCING NO PRECIPITATION. ANOTHER AREA OF HIGH PRESSURE
WILL MOVE IN BEHIND THE FRONT...WITH TEMPERATURES REMAINING SLIGHTLY
COOLER THAN NORMAL FOR FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL MAINTAIN ITS CONTROL OVER THE WEATHER
TODAY...WITH VERY TRANQUIL CONDITIONS EXPECTED. RH THROUGH THE
COLUMN IS VERY LOW (ESPECIALLY AROUND 850MB...ABOUT 10 PERCENT).
THE SKY GRIDS HAVE BEEN KEPT IN THE SUNNY CATEGORY...THOUGH THERE
MAY BE VERY ISOLATED WEAK CUMULUS DEVELOPMENT...OR A FEW PATCHES
OF VERY THIN CIRRUS.
ALTHOUGH FULL SUN IS EXPECTED...MIXING MAY BE SOMEWHAT LIMITED
WITH THE LIGHT WINDS...AND MODEL SOUNDINGS INDICATE MAKING IT UP
TO ABOUT 870MB-860MB. THERE IS SOME WARM ADVECTION EXPECTED TO
OCCUR ALOFT (WNW FLOW OUT OF THE BIG RIDGE TO THE WEST)...SO TEMPS
SHOULD CLIMB A FEW DEGREES FROM YESTERDAY.
JUMPING BACK TO THE VERY NEAR-TERM...THERE DOES APPEAR TO BE SOME
FOG POTENTIAL EARLY THIS MORNING. TEMPERATURES RE RADIATING
SIGNIFICANTLY AND RIVER VALLEYS ARE ALREADY BEGINNING TO FILL IN
WITH LOWERED VISIBILITIES. IN ADDITION...THE HRRR DEPICTS A VERY
LARGE AREA OF DENSE FOG DEVELOPING OVER NORTHERN INDIANA. NONE OF
THIS ADDS UP TO WIDESPREAD SIGNIFICANT FOG OVER THE ILN CWA...BUT
SOME PATCHY FOG HAS BEEN INCLUDED IN THE NORTHWEST CWA AND IN THE
RIVER VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE SHORT TERM OF THE FORECAST WILL BEGIN WITH THE CWA JUST AHEAD
OF A COLD FRONT MOVING IN FROM THE NORTH...AS THE WEDNESDAY HIGH
PRESSURE SHUNTS WESTWARD AND WEAKENS. THE FRONT IN QUESTION WILL
BE FAR REMOVED FROM ITS SOURCE IN A MID-LEVEL TROUGH CROSSING EAST
OF JAMES BAY. THE FRONT WILL BE MOVING INTO THE VERY DRY AIR MASS
OVER THE OHIO VALLEY. THE MODEL CONSENSUS ON LOW AND MID LEVEL RH
HAS COME UP SLIGHTLY FROM YESTERDAY...BUT THERE IS STILL LITTLE
TO INDICATE THAT MEASURABLE PRECIPITATION WILL OCCUR. AT
MOST...SOME SPRINKLES OR VERY LIGHT SHOWERS MAY BE POSSIBLE...BUT
THIS WILL NOT BE INCLUDED IN THE FORECAST. THE FRONT WILL BE
ACCOMPANIED BY A MARKED NNE WIND SHIFT...WITH A MASSIVE AMOUNT OF
NEGATIVE THETA-E ADVECTION. A NNE-TO-SSW GRADIENT HAS BEEN USED
FOR THE MAX TEMP GRIDS ON THURSDAY...ACCOUNTING FOR THE
FRONT...THOUGH THE TIMING OF THE TEMPERATURE CURVE STILL APPEARS
GENERALLY DIURNAL.
AFTER THE FRONT CROSSES THROUGH ON THURSDAY...HIGH PRESSURE IS
EXPECTED TO BUILD IN FROM THE NORTH ON THURSDAY NIGHT AND FRIDAY.
ALTHOUGH WINDS MAY NOT GO COMPLETELY CALM THURSDAY NIGHT...THE AIR
MASS WILL BE DRYING AND CAPABLE OF SOME RATHER COOL TEMPERATURES
(LOWER 50S AND UPPER 40S). THE ADVECTION PATTERN WILL REMAIN
NEUTRAL TO SLIGHTLY COOL ON FRIDAY...WITH THE OVERALL AIR MASS NOT
MODIFYING MUCH FROM THE COOL STARTING POINT. SO...DESPITE QUITE A
BIT OF SUN EXPECTED...MAX TEMPS WILL NOT BE ESPECIALLY HIGH (MID
70S IN CENTRAL OHIO TO AROUND 80 IN THE SW). THIS IS WARMER THAN
THE NAM BUT NOT AS WARM AS GFS/ECMWF 850MB TEMPS WOULD OTHERWISE
SUPPORT.
THE SURFACE HIGH WILL BE MOVING EAST OF THE REGION BY
SATURDAY...AS RIDGING BEGINS TO BUILD IN ALOFT. THIS WILL PUT THE
CWA IN A REGIME OF NORTHWEST FLOW ALOFT (EVENTUALLY SPILLING IN
SOME CLOUDS) AND SW FLOW AT THE SURFACE (WITH TEMPERATURES AND
DEWPOINTS BEGINNING TO RISE AGAIN).
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
STARTING ON SATURDAY...SHORT WAVE ENERGY ROUNDING THE CREST OF
THE UPPER RIDGE WILL COMBINE WITH LIMITED SURFACE CONVERGENCE AND
MODERATE INSTABILITY TO PRODUCE A CHANCE OF THUNDERSTORMS FROM
TIME TO TIME. THE BEST CHANCE APPEARS TO BE ON SUNDAY...WHEN A
FRONTAL BOUNDARY SAGGING FROM THE NORTH MAY BE THE FOCUS FOR
CONVECTIVE DEVELOPMENT. WITH NO STRONG FORCING INDICATED FOR THE
REST OF THE PERIOD...KEPT POPS UNDER THE 25 PERCENT THRESHOLD
REQUIRED TO SHOW UP IN THE FORECAST.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THE GREAT LAKES AND THE OHIO VALLEY WILL REMAIN UNDER A NORTHWEST
FLOW PATTERN ALOFT THROUGH THE TAF PERIOD. AT THE SURFACE...HIGH
PRESSURE ORIENTED OVER THE OHIO VALLEY WILL MOVE SOUTH AND
SOUTHWEST OF THE RIVER BY TONIGHT AS A WEAK COLD FRONT PUSHES IN
FROM THE NORTH. THE FRONT SHOULD BE SOUTH OF THE RIVER NEAR 12Z
THURSDAY. THE FRONT IS MOISTURE STARVED...SO ONLY A MIX OF HIGH
CLOUDS AND SOME STRATOCUMULUS CLOUDS ARE EXPECTED.
IN THE MEANTIME...MAINLY CLEAR SKIES WILL DOMINATE THROUGH THE
REMAINDER OF THE MORNING HOURS AND INTO THE DAYTIME. RIVER FOG
NEAR KLUK AND PATCHY FOG/MIST AT KILN/KLCK SHOULD DISSIPATE
QUICKLY BETWEEN 13Z AND 14Z.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
345 AM EDT WED SEP 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE OHIO VALLEY TODAY. ON
THURSDAY...A MOISTURE-STARVED COLD FRONT WILL MOVE SOUTH THROUGH THE
REGION...PRODUCING NO PRECIPITATION. ANOTHER AREA OF HIGH PRESSURE
WILL MOVE IN BEHIND THE FRONT...WITH TEMPERATURES REMAINING SLIGHTLY
COOLER THAN NORMAL FOR FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL MAINTAIN ITS CONTROL OVER THE WEATHER
TODAY...WITH VERY TRANQUIL CONDITIONS EXPECTED. RH THROUGH THE
COLUMN IS VERY LOW (ESPECIALLY AROUND 850MB...ABOUT 10 PERCENT).
THE SKY GRIDS HAVE BEEN KEPT IN THE SUNNY CATEGORY...THOUGH THERE
MAY BE VERY ISOLATED WEAK CUMULUS DEVELOPMENT...OR A FEW PATCHES
OF VERY THIN CIRRUS.
ALTHOUGH FULL SUN IS EXPECTED...MIXING MAY BE SOMEWHAT LIMITED
WITH THE LIGHT WINDS...AND MODEL SOUNDINGS INDICATE MAKING IT UP
TO ABOUT 870MB-860MB. THERE IS SOME WARM ADVECTION EXPECTED TO
OCCUR ALOFT (WNW FLOW OUT OF THE BIG RIDGE TO THE WEST)...SO TEMPS
SHOULD CLIMB A FEW DEGREES FROM YESTERDAY.
JUMPING BACK TO THE VERY NEAR-TERM...THERE DOES APPEAR TO BE SOME
FOG POTENTIAL EARLY THIS MORNING. TEMPERATURES RE RADIATING
SIGNIFICANTLY AND RIVER VALLEYS ARE ALREADY BEGINNING TO FILL IN
WITH LOWERED VISIBILITIES. IN ADDITION...THE HRRR DEPICTS A VERY
LARGE AREA OF DENSE FOG DEVELOPING OVER NORTHERN INDIANA. NONE OF
THIS ADDS UP TO WIDESPREAD SIGNIFICANT FOG OVER THE ILN CWA...BUT
SOME PATCHY FOG HAS BEEN INCLUDED IN THE NORTHWEST CWA AND IN THE
RIVER VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE SHORT TERM OF THE FORECAST WILL BEGIN WITH THE CWA JUST AHEAD
OF A COLD FRONT MOVING IN FROM THE NORTH...AS THE WEDNESDAY HIGH
PRESSURE SHUNTS WESTWARD AND WEAKENS. THE FRONT IN QUESTION WILL
BE FAR REMOVED FROM ITS SOURCE IN A MID-LEVEL TROUGH CROSSING EAST
OF JAMES BAY. THE FRONT WILL BE MOVING INTO THE VERY DRY AIR MASS
OVER THE OHIO VALLEY. THE MODEL CONSENSUS ON LOW AND MID LEVEL RH
HAS COME UP SLIGHTLY FROM YESTERDAY...BUT THERE IS STILL LITTLE
TO INDICATE THAT MEASURABLE PRECIPITATION WILL OCCUR. AT
MOST...SOME SPRINKLES OR VERY LIGHT SHOWERS MAY BE POSSIBLE...BUT
THIS WILL NOT BE INCLUDED IN THE FORECAST. THE FRONT WILL BE
ACCOMPANIED BY A MARKED NNE WIND SHIFT...WITH A MASSIVE AMOUNT OF
NEGATIVE THETA-E ADVECTION. A NNE-TO-SSW GRADIENT HAS BEEN USED
FOR THE MAX TEMP GRIDS ON THURSDAY...ACCOUNTING FOR THE
FRONT...THOUGH THE TIMING OF THE TEMPERATURE CURVE STILL APPEARS
GENERALLY DIURNAL.
AFTER THE FRONT CROSSES THROUGH ON THURSDAY...HIGH PRESSURE IS
EXPECTED TO BUILD IN FROM THE NORTH ON THURSDAY NIGHT AND FRIDAY.
ALTHOUGH WINDS MAY NOT GO COMPLETELY CALM THURSDAY NIGHT...THE AIR
MASS WILL BE DRYING AND CAPABLE OF SOME RATHER COOL TEMPERATURES
(LOWER 50S AND UPPER 40S). THE ADVECTION PATTERN WILL REMAIN
NEUTRAL TO SLIGHTLY COOL ON FRIDAY...WITH THE OVERALL AIR MASS NOT
MODIFYING MUCH FROM THE COOL STARTING POINT. SO...DESPITE QUITE A
BIT OF SUN EXPECTED...MAX TEMPS WILL NOT BE ESPECIALLY HIGH (MID
70S IN CENTRAL OHIO TO AROUND 80 IN THE SW). THIS IS WARMER THAN
THE NAM BUT NOT AS WARM AS GFS/ECMWF 850MB TEMPS WOULD OTHERWISE
SUPPORT.
THE SURFACE HIGH WILL BE MOVING EAST OF THE REGION BY
SATURDAY...AS RIDGING BEGINS TO BUILD IN ALOFT. THIS WILL PUT THE
CWA IN A REGIME OF NORTHWEST FLOW ALOFT (EVENTUALLY SPILLING IN
SOME CLOUDS) AND SW FLOW AT THE SURFACE (WITH TEMPERATURES AND
DEWPOINTS BEGINNING TO RISE AGAIN).
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
STARTING ON SATURDAY...SHORT WAVE ENERGY ROUNDING THE CREST OF
THE UPPER RIDGE WILL COMBINE WITH LIMITED SURFACE CONVERGENCE AND
MODERATE INSTABILITY TO PRODUCE A CHANCE OF THUNDERSTORMS FROM
TIME TO TIME. THE BEST CHANCE APPEARS TO BE ON SUNDAY...WHEN A
FRONTAL BOUNDARY SAGGING FROM THE NORTH MAY BE THE FOCUS FOR
CONVECTIVE DEVELOPMENT. WITH NO STRONG FORCING INDICATED FOR THE
REST OF THE PERIOD...KEPT POPS UNDER THE 25 PERCENT THRESHOLD
REQUIRED TO SHOW UP IN THE FORECAST.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
THE GREAT LAKES AND THE OHIO VALLEY WILL REMAIN UNDER A NORTHWEST
FLOW PATTERN ALOFT THROUGH THE TAF PERIOD. AT THE SURFACE...HIGH
PRESSURE ORIENTED OVER THE OHIO VALLEY WILL MOVE SOUTH OF THE
RIVER BY TONIGHT AS A WEAK COLD FRONT PUSHES IN FROM THE NORTH.
THE FRONT SHOULD BE SOUTH OF THE RIVER NEAR OR AFTER 12Z THURSDAY.
THE FRONT IS MOISTURE STARVED...SO ONLY A MIX OF HIGH CLOUDS AND
SOME STRATOCUMULUS CLOUDS ARE EXPECTED.
IN THE MEANTIME...MAINLY CLEAR SKIES WILL DOMINATE THROUGH THE
REMAINDER OF THE MORNING HOURS AND INTO THE DAYTIME. SOME RIVER
VALLEY FOG IS EXPECTED TO DEVELOP AT KLUK. AM EXPECTING THIS TO BE
FAIRLY SHALLOW...AND WITH THE LACK OF ANY STEERING FLOW FROM THE
EAST OR SOUTHEAST...THE FOG SHOULD RESULT IN CONSIDERABLE
VISIBILITY FLUCTUATIONS. HAVE GONE WITH IFR VSBYS BY 08Z WITH SOME
VLIFR CONDITIONS BETWEEN 09Z AND 12Z. ELSEWHERE SOME MVFR VSBYS
WILL LIKELY DEVELOP AT THE MORE RURAL AIRPORTS OF KILN AND KLCK.
KLCK MAY EVEN EXPERIENCE SOME BRIEF IFR VSBYS TOWARD MORNING. ALL
FOG/MIST SHOULD QUICKLY DISSIPATE BETWEEN 12Z AND 14Z.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1241 PM CDT WED SEP 4 2013
.UPDATE...
ISSUED AT 1241 PM CDT WED SEP 4 2013
PRECIPITATION HARD TO COME BY AFTER MAIN AREA OF HIGH BASED SHOWERS
SHIFTED SOUTH OF THE CWA EARLIER THIS MORNING. FAIRLY EASY TO TELL
WHERE ANY POTENTIAL WOULD BE BASED ON NARROW BAND OF CLOUDS/SPOTTY
ECHOES ON REGIONAL RADAR. SIMILAR TO YESTERDAY...THIS AREA LINES UP
WELL WITH MID LEVEL THETA-E GRADIENT/ADVECTION. HOWEVER...AIRPORT
OBSERVATIONS BENEATH A COUPLE OF AREAS OF ECHOES LITTLE IF ANY RAIN
REACHING THE GROUND DUE TO DRY AIR BELOW ABOUT 8-9KFT...SO REMOVED
MOST POPS FROM THE REMAINDER OF THE AFTERNOON INTO THIS EVENING.
WEAK LOW LEVEL JET MAY ASSIST SPOTTY DEVELOPMENT OVERNIGHT SO HAVE
KEPT ISOLATED POPS IN FOR TONIGHT SO FAR. HOWEVER MID LEVEL SUPPORT
SEEMS TO WANE AS ALREADY WEAK WAVE SHEARS OUT AND FLOW BECOMES LESS
CONVERGENT...SO WILL REEVALUATE THESE POPS BEFORE AFTERNOON PACKAGE
IS FINALIZED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED SEP 4 2013
CURRENTLY SEEING SOME SCATTERED SHOWERS AND A FEW THUNDERSTORMS
ACROSS SOUTH CENTRAL SOUTH DAKOTA. IN GENERAL EXPECT THE COVERAGE OF
THESE SHOWERS TO DECREASE DURING THE MORNING AS WE LOSE THE LOW
LEVEL JET. HOWEVER...A WEAK MID LEVEL WAVE WILL REMAIN IN THE AREA
THROUGH THE DAY...WITH DECENT MID LEVEL MOISTURE AND SOME THETAE
ADVECTION. THUS WILL KEEP SLIGHT CHANCE POPS THROUGH THE
DAY...MAINLY FROM JUST EAST OF THE INTERSTATE 29 CORRIDOR AND POINTS
WEST. DRY AIR IN THE LOWER LEVELS SHOULD MAKE IT TOUGH FOR MUCH OF
THIS MID LEVEL ACTIVITY TO REACH THE GROUND...BUT DO THINK A FEW
SHOWERS ARE POSSIBLE. THE HRRR IS MOST AGGRESSIVE WITH THE
ACTIVITY...AND WHILE IT SEEMS OVERDONE...IT DOES GIVE ANOTHER REASON
TO KEEP THE SLIGHT CHANCE POPS. INSTABILITY IS MARGINAL...BUT GIVEN
THE HIGH BASED NATURE OF THESE STORMS THERE MAY BE JUST ENOUGH TO
GET A LIGHTNING STRIKE OR TWO WITH THE SHOWERS EVERY ONCE IN A
WHILE...SO KEPT THUNDER IN FOR NOW. HIGH TEMPERATURES TODAY SHOULD
BE IN THE 80S...WITH THE CLOUD COVER PREVENTING FULL HEATING FOR
MOST OF THE AREA. MUCH OF THE SAME TONIGHT...WITH THE MID LEVEL WAVE
IN THE VICINITY...EXPECTING A MOSTLY CLOUDY NIGHT. COULD SEE A
SLIGHT UPTICK IN SHOWER ACTIVITY THE FIRST PORTION OF THE NIGHT AS
THE LOW LEVEL JET GETS GOING...BUT NOT REAL CONFIDENT IN THAT. THUS
WILL KEEP JUST SLIGHT CHANCE POPS FOR NOW. EITHER WAY NOT EXPECTING
MUCH. DID RAISE LOWS SOME WITH THE NEWER GUIDANCE COMING IN A BIT
WARMER...SUGGESTING ANY COOLER AND DRYER LOW LEVEL AIR STAYS
NORTHEAST OF THE CWA. GENERALLY LOOKING FOR LOW TO MID 60S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED SEP 4 2013
AN UPPER LEVEL WAVE AND A WEAK MID LEVEL BOUNDARY COULD SPARK A FEW
SHOWERS OVER THE FAR EASTERN CWA ON THURSDAY BUT WITH FAIRLY DRY LOW
LEVELS AND WEAK MID LEVEL INSTABILITY NO PLAN TO ADD ANY POPS AS
WHATEVER COULD DEVELOP WOULD REMAIN ON THE LIGHT SIDE. AS THE WAVE
EXITS WILL BE A BIT OF A EASTERLY COMPONENT TO THE WIND SO WHILE THE
DAY WILL BE WARM EXPECT NO MAJOR MIXING. HIGHS MAINLY IN THE LOWER
TO MID 80S.
THURSDAY NIGHT INTO FRIDAY WILL SEE A TIGHTENING OF THE GRADIENT AND
AN INCREASE IN THE LOW LEVEL TEMPERATURE FIELD. THIS WILL LEAD
TOWARDS WARM LOWS IN THE MID AND UPPER 60S AND HIGHS ON FRIDAY WELL
INTO THE 90S WITH SOMETHING AROUND 100 POSSIBLE IN CENTRAL SOUTH
DAKOTA.
A STRONG RIDGE OF HIGH PRESSURE WILL BE IN PLACE FOR MUCH OF THE
PERIOD...THEN SOME HINTS THAT IT SHOULD BREAK DOWN A BIT EARLY NEXT
WEEK AS A WEAK SHORTWAVE MOVES THROUGH THE NORTHERN ROCKIES AND INTO
THE NORTHERN PLAINS. OVERALL THE MODELS ARE IN PRETTY GOOD AGREEMENT
WHICH SUGGESTS VERY WARM READINGS SATURDAY THROUGH MONDAY...WITH THE
HOTTEST TEMPERATURES LIKE FRIDAY AND SATURDAY AHEAD OF A WEAK
BOUNDARY THAT IS PROGGED TO LEAK SOUTHWARD INTO THE AREA. NOT MUCH
PUNCH FROM THIS BOUNDARY AS THE WAVE THAT IS FORCING IT SOUTH IS
MOVING SOUTHEAST THROUGH THE GREAT LAKES REGION. THE RIDGE
REESTABLISHES AGAIN ON MONDAY AS THE WEAK WAVE MOVES ONTO THE PLAINS
AND TRIES TO BRING A BOUNDARY INTO THE AREA ON TUESDAY. IF THIS WAVE
IS A LITTLE SLOWER TUESDAY COULD PROVE TO BE VERY WARM AS WELL. WILL
CONFINE POPS TO THE TIMING OF THE TWO FRONTS WHICH SHOULD MAINLY BE
SATURDAY NIGHT INTO SUNDAY AND MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1241 PM CDT WED SEP 4 2013
VFR CONDITIONS THROUGH THE PERIOD. ISOLATED SHRA OR TSRA REMAIN
POSSIBLE...THOUGH WITH SPOTTY NATURE AND DRY AIR BENEATH MID LEVEL
CLOUD BASE LIMITING PRECIP EVEN REAACHING THE GROUND...HAVE LITTLE IF
ANY MENTION IN THE TAFS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...JH
SHORT TERM...CHENARD
LONG TERM...08
AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
631 AM CDT WED SEP 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED SEP 4 2013
CURRENTLY SEEING SOME SCATTERED SHOWERS AND A FEW THUNDERSTORMS
ACROSS SOUTH CENTRAL SOUTH DAKOTA. IN GENERAL EXPECT THE COVERAGE OF
THESE SHOWERS TO DECREASE DURING THE MORNING AS WE LOSE THE LOW
LEVEL JET. HOWEVER...A WEAK MID LEVEL WAVE WILL REMAIN IN THE AREA
THROUGH THE DAY...WITH DECENT MID LEVEL MOISTURE AND SOME THETAE
ADVECTION. THUS WILL KEEP SLIGHT CHANCE POPS THROUGH THE
DAY...MAINLY FROM JUST EAST OF THE INTERSTATE 29 CORRIDOR AND POINTS
WEST. DRY AIR IN THE LOWER LEVELS SHOULD MAKE IT TOUGH FOR MUCH OF
THIS MID LEVEL ACTIVITY TO REACH THE GROUND...BUT DO THINK A FEW
SHOWERS ARE POSSIBLE. THE HRRR IS MOST AGGRESSIVE WITH THE
ACTIVITY...AND WHILE IT SEEMS OVERDONE...IT DOES GIVE ANOTHER REASON
TO KEEP THE SLIGHT CHANCE POPS. INSTABILITY IS MARGINAL...BUT GIVEN
THE HIGH BASED NATURE OF THESE STORMS THERE MAY BE JUST ENOUGH TO
GET A LIGHTNING STRIKE OR TWO WITH THE SHOWERS EVERY ONCE IN A
WHILE...SO KEPT THUNDER IN FOR NOW. HIGH TEMPERATURES TODAY SHOULD
BE IN THE 80S...WITH THE CLOUD COVER PREVENTING FULL HEATING FOR
MOST OF THE AREA. MUCH OF THE SAME TONIGHT...WITH THE MID LEVEL WAVE
IN THE VICINITY...EXPECTING A MOSTLY CLOUDY NIGHT. COULD SEE A
SLIGHT UPTICK IN SHOWER ACTIVITY THE FIRST PORTION OF THE NIGHT AS
THE LOW LEVEL JET GETS GOING...BUT NOT REAL CONFIDENT IN THAT. THUS
WILL KEEP JUST SLIGHT CHANCE POPS FOR NOW. EITHER WAY NOT EXPECTING
MUCH. DID RAISE LOWS SOME WITH THE NEWER GUIDANCE COMING IN A BIT
WARMER...SUGGESTING ANY COOLER AND DRYER LOW LEVEL AIR STAYS
NORTHEAST OF THE CWA. GENERALLY LOOKING FOR LOW TO MID 60S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED SEP 4 2013
AN UPPER LEVEL WAVE AND A WEAK MID LEVEL BOUNDARY COULD SPARK A FEW
SHOWERS OVER THE FAR EASTERN CWA ON THURSDAY BUT WITH FAIRLY DRY LOW
LEVELS AND WEAK MID LEVEL INSTABILITY NO PLAN TO ADD ANY POPS AS
WHATEVER COULD DEVELOP WOULD REMAIN ON THE LIGHT SIDE. AS THE WAVE
EXITS WILL BE A BIT OF A EASTERLY COMPONENT TO THE WIND SO WHILE THE
DAY WILL BE WARM EXPECT NO MAJOR MIXING. HIGHS MAINLY IN THE LOWER
TO MID 80S.
THURSDAY NIGHT INTO FRIDAY WILL SEE A TIGHTENING OF THE GRADIENT AND
AN INCREASE IN THE LOW LEVEL TEMPERATURE FIELD. THIS WILL LEAD
TOWARDS WARM LOWS IN THE MID AND UPPER 60S AND HIGHS ON FRIDAY WELL
INTO THE 90S WITH SOMETHING AROUND 100 POSSIBLE IN CENTRAL SOUTH
DAKOTA.
A STRONG RIDGE OF HIGH PRESSURE WILL BE IN PLACE FOR MUCH OF THE
PERIOD...THEN SOME HINTS THAT IT SHOULD BREAK DOWN A BIT EARLY NEXT
WEEK AS A WEAK SHORTWAVE MOVES THROUGH THE NORTHERN ROCKIES AND INTO
THE NORTHERN PLAINS. OVERALL THE MODELS ARE IN PRETTY GOOD AGREEMENT
WHICH SUGGESTS VERY WARM READINGS SATURDAY THROUGH MONDAY...WITH THE
HOTTEST TEMPERATURES LIKE FRIDAY AND SATURDAY AHEAD OF A WEAK
BOUNDARY THAT IS PROGGED TO LEAK SOUTHWARD INTO THE AREA. NOT MUCH
PUNCH FROM THIS BOUNDARY AS THE WAVE THAT IS FORCING IT SOUTH IS
MOVING SOUTHEAST THROUGH THE GREAT LAKES REGION. THE RIDGE
REESTABLISHES AGAIN ON MONDAY AS THE WEAK WAVE MOVES ONTO THE PLAINS
AND TRIES TO BRING A BOUNDARY INTO THE AREA ON TUESDAY. IF THIS WAVE
IS A LITTLE SLOWER TUESDAY COULD PROVE TO BE VERY WARM AS WELL. WILL
CONFINE POPS TO THE TIMING OF THE TWO FRONTS WHICH SHOULD MAINLY BE
SATURDAY NIGHT INTO SUNDAY AND MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 629 AM CDT WED SEP 4 2013
MAINLY VFR CONDITIONS THROUGH THE PERIOD. COULD BE A FEW ISOLATED
SHOWERS OR THUNDERSTORMS TODAY INTO TONIGHT. BUT COVERAGE IS EXPECTED
TO BE TOO SPARSE TO WARRANT MENTION IN THE TAFS AT THIS TIME.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...08
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
338 AM CDT WED SEP 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED SEP 4 2013
CURRENTLY SEEING SOME SCATTERED SHOWERS AND A FEW THUNDERSTORMS
ACROSS SOUTH CENTRAL SOUTH DAKOTA. IN GENERAL EXPECT THE COVERAGE OF
THESE SHOWERS TO DECREASE DURING THE MORNING AS WE LOSE THE LOW
LEVEL JET. HOWEVER...A WEAK MID LEVEL WAVE WILL REMAIN IN THE AREA
THROUGH THE DAY...WITH DECENT MID LEVEL MOISTURE AND SOME THETAE
ADVECTION. THUS WILL KEEP SLIGHT CHANCE POPS THROUGH THE
DAY...MAINLY FROM JUST EAST OF THE INTERSTATE 29 CORRIDOR AND POINTS
WEST. DRY AIR IN THE LOWER LEVELS SHOULD MAKE IT TOUGH FOR MUCH OF
THIS MID LEVEL ACTIVITY TO REACH THE GROUND...BUT DO THINK A FEW
SHOWERS ARE POSSIBLE. THE HRRR IS MOST AGGRESSIVE WITH THE
ACTIVITY...AND WHILE IT SEEMS OVERDONE...IT DOES GIVE ANOTHER REASON
TO KEEP THE SLIGHT CHANCE POPS. INSTABILITY IS MARGINAL...BUT GIVEN
THE HIGH BASED NATURE OF THESE STORMS THERE MAY BE JUST ENOUGH TO
GET A LIGHTNING STRIKE OR TWO WITH THE SHOWERS EVERY ONCE IN A
WHILE...SO KEPT THUNDER IN FOR NOW. HIGH TEMPERATURES TODAY SHOULD
BE IN THE 80S...WITH THE CLOUD COVER PREVENTING FULL HEATING FOR
MOST OF THE AREA. MUCH OF THE SAME TONIGHT...WITH THE MID LEVEL WAVE
IN THE VICINITY...EXPECTING A MOSTLY CLOUDY NIGHT. COULD SEE A
SLIGHT UPTICK IN SHOWER ACTIVITY THE FIRST PORTION OF THE NIGHT AS
THE LOW LEVEL JET GETS GOING...BUT NOT REAL CONFIDENT IN THAT. THUS
WILL KEEP JUST SLIGHT CHANCE POPS FOR NOW. EITHER WAY NOT EXPECTING
MUCH. DID RAISE LOWS SOME WITH THE NEWER GUIDANCE COMING IN A BIT
WARMER...SUGGESTING ANY COOLER AND DRYER LOW LEVEL AIR STAYS
NORTHEAST OF THE CWA. GENERALLY LOOKING FOR LOW TO MID 60S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED SEP 4 2013
AN UPPER LEVEL WAVE AND A WEAK MID LEVEL BOUNDARY COULD SPARK A FEW
SHOWERS OVER THE FAR EASTERN CWA ON THURSDAY BUT WITH FAIRLY DRY LOW
LEVELS AND WEAK MID LEVEL INSTABILITY NO PLAN TO ADD ANY POPS AS
WHATEVER COULD DEVELOP WOULD REMAIN ON THE LIGHT SIDE. AS THE WAVE
EXITS WILL BE A BIT OF A EASTERLY COMPONENT TO THE WIND SO WHILE THE
DAY WILL BE WARM EXPECT NO MAJOR MIXING. HIGHS MAINLY IN THE LOWER
TO MID 80S.
THURSDAY NIGHT INTO FRIDAY WILL SEE A TIGHTENING OF THE GRADIENT AND
AN INCREASE IN THE LOW LEVEL TEMPERATURE FIELD. THIS WILL LEAD
TOWARDS WARM LOWS IN THE MID AND UPPER 60S AND HIGHS ON FRIDAY WELL
INTO THE 90S WITH SOMETHING AROUND 100 POSSIBLE IN CENTRAL SOUTH
DAKOTA.
A STRONG RIDGE OF HIGH PRESSURE WILL BE IN PLACE FOR MUCH OF THE
PERIOD...THEN SOME HINTS THAT IT SHOULD BREAK DOWN A BIT EARLY NEXT
WEEK AS A WEAK SHORTWAVE MOVES THROUGH THE NORTHERN ROCKIES AND INTO
THE NORTHERN PLAINS. OVERALL THE MODELS ARE IN PRETTY GOOD AGREEMENT
WHICH SUGGESTS VERY WARM READINGS SATURDAY THROUGH MONDAY...WITH THE
HOTTEST TEMPERATURES LIKE FRIDAY AND SATURDAY AHEAD OF A WEAK
BOUNDARY THAT IS PROGGED TO LEAK SOUTHWARD INTO THE AREA. NOT MUCH
PUNCH FROM THIS BOUNDARY AS THE WAVE THAT IS FORCING IT SOUTH IS
MOVING SOUTHEAST THROUGH THE GREAT LAKES REGION. THE RIDGE
REESTABLISHES AGAIN ON MONDAY AS THE WEAK WAVE MOVES ONTO THE PLAINS
AND TRIES TO BRING A BOUNDARY INTO THE AREA ON TUESDAY. IF THIS WAVE
IS A LITTLE SLOWER TUESDAY COULD PROVE TO BE VERY WARM AS WELL. WILL
CONFINE POPS TO THE TIMING OF THE TWO FRONTS WHICH SHOULD MAINLY BE
SATURDAY NIGHT INTO SUNDAY AND MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1017 PM CDT TUE SEP 3 2013
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD. THERE WILL BE A
POSSIBILITY OF SCATTERED SHOWERS AND THUNDERSTORMS THROUGH SOUTH
CENTRAL SOUTH DAKOTA...LOWER JAMES RIVER VALLEY...AND INTO THE
MISSOURI RIVER VALLEY FOR TONIGHT AND TOMORROW. THE MAJORITY OF
THIS ACTIVITY IS EXPECTED TO REMAIN WEST OF THE TAF SITES...SO DID
NOT INCLUDE IN THE TAFS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...08
AVIATION...JM
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1113 PM MDT TUE SEP 3 2013
.UPDATE...
ISSUED AT 742 PM MDT TUE SEP 3 2013
00Z KUNR SOUNDING SHOWS MLCIN. LATEST CONVECTIVE ALLOWING MODELS
SHOW LITTLE IN THE WAY OF SHRA/TSRA OVERNIGHT. UPSTREAM WAVES OVER
WESTERN WY WILL HAVE LITTLE MUCAPE TO WORK WITH OVERNIGHT. DIURNAL
LESSENING OF INSTABILITY NOTED ON MESOANALYSIS PRODUCTS. WILL
REDUCE POPS WITH UPDATE FOR ENTIRE CWA AND LEAVE A SMALL ARC OF 15
POPS FROM SOUTHEAST MT INTO SOUTH CENTRAL SD.
&&
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 234 PM MDT TUE SEP 3 2013
WATER VAPOR IMAGERY HAS THE UPPER RIDGE BUILDING FROM THE ROCKIES
INTO THE PLAINS. SEVERAL SHORTWAVES ARE MOVING THROUGH THE RIDGE
WITH ONE OVER CENTRAL SOUTH DAKOTA...TWO SMALL WAVES IN WESTERN AND
CENTRAL WYOMING...AND A LARGER WAVE NEAR SALT LAKE CITY. RADAR HAS
CONVECTION EXTENDING THROUGH CENTRAL SOUTH DAKOTA...WITH NOT MUCH
HAPPENING OVER WYOMING WITH THE SMALLER WAVES. VISIBLE SATELLITE IS
SHOWING SOME CU DEVELOPING OVER THE BLACK HILLS...PARTS OF
NORTHEASTERN WYOMING AND SOUTHWEST SOUTH DAKOTA. AT THE SURFACE...AN
AREA OF LOW PRESSURE IS LOCATED OVER SOUTHWESTERN SOUTH DAKOTA WITH
A WARM FRONT EXTENDING THROUGH SOUTH CENTRAL SOUTH DAKOTA AND A LEE
TROF THROUGH THE BLACK HILLS AND EASTERN MONTANA.
FOR TONIGHT...NOT CONFIDENT IN THE PLACEMENT OF CONVECTION WITH THE
HRRR AND RAP MODELS SHOWING LITTLE IF ANY CONVECTION AND LESS MLCAPE
THAN THE NAM OR GFS. EXPECT SOME CONVECTION WILL FIRE DUE TO DIURNAL
HEATING...HOWEVER SHEAR IS NOT OVERLY IMPRESSIVE FOR SEVERE
POTENTIAL. MAIN CONCERN WITH ANY STORM THAT DEVELOPS TONIGHT WILL BE
HEAVY RAIN POTENTIAL. PWS ARE 200 PERCENT OF NORMAL WITH STORM
MOVEMENT AROUND 15KTS. HOWEVER WITH MY LACK OF CONFIDENCE ON STORM
DEVELOPMENT AND PLACEMENT HAVE DECIDED TO FORGO ANY TYPE OF HYDRO
HEADLINES AT THIS TIME.
ON WEDNESDAY/WEDNESDAY NIGHT...UPPER RIDGE SHOULD AMPLIFY FURTHER
INTO THE NORTHERN PLAINS. HOWEVER...TEMPS WILL BE FEW DEGREES COOLER
AS SURFACE LOW SHIFTS INTO EASTERN COLORADO AND PULLS IN SLIGHTLY
COOLER AIR FROM THE NORTH. BEST CHANCE FOR ANY CONVECTION WILL BE
ACROSS THE FAR WESTERN ZONES NEAR THE INVERTED TROF EXTENDING NORTH
FROM THE SURFACE LOW OVER EASTERN COLORADO AND POSSIBLY IN SOUTH
CENTRAL SOUTH DAKOTA WITH THE WARM FRONT EXTENDING THROUGH NORTHERN
NEBRASKA.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 234 PM MDT TUE SEP 3 2013
LONG WAVE RIDGE OVER CWA WITH A LONG WAVE TROF OVER THE LOWER GREAT
LAKES AND JUST OFF THE WEST COAST. GFS AND ECMWF SHOW PROGRESSION
OF STRONG SHORT WAVE OUT OF THE WEST COAST TROF TO ERN MT BY 12Z
MON AS LONG WAVE RIDGE UNDERGOES FLATTENING AND DISCONTINUOUS
RETROGRESSION TO 135W BY 12Z MON. RIDGE THEN AMPLIFIES AND MOVES
SLOWLY E WARD DURING MID WEEK.
THIS EVOLUTION ALLOWS SIGNIFICANT SURGE OF COOLER AIR FOLLOWING E
WARD MOVEMENT OF SHORT WAVE TROF AND A RETURN TO MORE SEASONAL
TEMPERATURES TUES. THE COLD FRONT AND UPPER SUPPORT LEADING THIS
SURGE WILL LIKELY RESULT IN SHOWERS AND TSTMS REFLECTED IN HIGHER
POPS SATURDAY INTO MONDAY.
STAYED QUITE CLOSE TO GUIDANCE WITH TEMPERATURES THROUGH THE
EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1111 PM MDT TUE SEP 3 2013
ISOLATED SHRA/TSRA MAY OCCUR FROM ABOUT K2WX TO KPHP TO KICR
OVERNIGHT...POSSIBLY LINGERING INTO SOUTH CENTRAL SD EARLY
WEDNESDAY MORNING. ADDITIONAL TSRA MAY DEVELOP OVER NORTHEAST
WY/FAR WESTERN SD WEDNESDAY AFTERNOON/EVENING. OTHERWISE VFR
CONDITIONS WILL CONTINUE THROUGH THE PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...MLS
LONG TERM...BARBER
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1212 PM CDT WED SEP 4 2013
.DISCUSSION...
18Z TAF DISCUSSION IN AVIATION SECTION...
&&
.AVIATION...
KCLL/KUTS/KCXO...OVERALL VFR CIGS WITH LIGHT EAST WINDS. SHOULD
HAVE TCU THIS AFTERNOON AND TOMORROW BUT TERMINALS MAY BE ON EDGE
OF HIGHER MOISTURE FOR CONVECTION TO FORM. CONVECTION STILL
POSSIBLE BUT CONFIDENCE RATHER LOW AT THIS TIME.
KIAH/KHOU/KSGR...WILL CARRY VCSH/VCTS FOR TERMINALS THIS
AFTERNOON AND TOMORROW AFTERNOON. THINK BEST CHANCES FOR TSRA ARE
THIS AFTERNOON WITH HEATING AND CONVERGENCE ON SEA BREEZE OR
OUTFLOW FROM MORNING CONVECTION ALONG THE COAST. HRRR SEEMS TO
HAVE A GOOD HANDLE ON THIS. WILL AMMEND TAFS IF CONVECTION AFFECTS
TERMINALS BUT NOT HIGH ENOUGH CONFIDENCE TO PUT IN TAFS NOW. SAME
WILL BE SAID FOR TOMORROW AFTERNOON.
KLBX/KGLS...CONVECTION THIS MORNING HAS WEAKENED AND NOT EXPECTED
MUCH MORE ACTIVITY THIS AFTERNOON AS SEA BREEZE MOVES INLAND.
EXPECT ANOTHER ROUND OF SHOWERS IN THE MORNING FOR KGLS WHICH
COULD AFFECT KLBX. FOR NOW WILL WAIT AND SEE AS STILL PLENTY OF
TIME TO UPDATE TAFS IF CONVECTION BECOMES MORE WIDESPREAD IN THE
MORNING.
39
&&
.PREV DISCUSSION... /ISSUED 1124 AM CDT WED SEP 4 2013/
DISCUSSION...
STORMS RIGHT ALONG THE COAST PERSISTING BUT WE ARE SEEING SIGNS OF
WEAKENING. OTHERWISE NOT A LOT OF CHANGES (IF ANY) FOR THIS UPDATE
WITH THE GOING FCST OF ISO/WIDELY SCT PCPN FOR THE REST OF THE AF-
TERNOON. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 98 75 98 / 20 10 20 10 20
HOUSTON (IAH) 99 76 97 76 96 / 30 10 20 10 20
GALVESTON (GLS) 90 81 90 80 89 / 30 20 30 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...41
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
605 AM CDT WED SEP 4 2013
.DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...
FCST SOUNDINGS SHOW LOWER PW VALUES THAN YESTERDAY WITH VALUES
PEAKING NEAR 1.5 INCHES OVER THE NORTH AND 1.9 INCHES SOUTH.
DAYTIME HEATING AND THE SEA BREEZE LOOK TO BE THE CATALYST FOR
SHRA/TSRA DEVELOPMENT LATER TODAY. THE RAP AND HRRR SUPPORT SCT
SHRA/TSRA OVER MAINLY THE SOUTHERN HALF OF THE AREA TODAY. OUTSIDE
OF AREAS OF CONVECTION...VFR CONDS EXPECTED TODAY WITH GENERALLY
LIGHT WINDS. 43
&&
.PREV DISCUSSION... /ISSUED 452 AM CDT WED SEP 4 2013/
DISCUSSION...
EARLIER SHOWERS NEAR COLLEGE STATION HAVE WEAKENED AND MOVED OUT
OF THE AREA TONIGHT. THE BOUNDARY THAT WAS DRAPED ACROSS THE
NORTHERN ZONES YESTERDAY HAS ALREADY STARTED TO WASH OUT. AT 200
MB THE UPPER LEVEL RIDGE HAS STARTED TO MOVE EASTWARD PUSHING THE
BEST UPPER LEVEL DIFFLUENCE TO THE EAST AS WELL. THE RIDGE AT 500
MB HAS ALSO STARTED TO STRENGTHEN WITH HEIGHTS RISING. HEIGHTS
ACROSS SOUTHEAST TEXAS HAVE ALSO RISEN SOME. MOISTURE SHOULD CONTINUE
TO FALL TODAY ESPECIALLY IN THE NORTHERN ZONES. FORECAST SOUNDINGS
SHOW PWATS DROPPING TO AROUND 1.6" AT KCLL. CURRENT PWATS (AS PER
GPS MET) STILL SHOW THE DRIER AIR HUNG UP FURTHER NORTH THOUGH.
MODELS SEEM TO HAVE BEEN TO AGGRESSIVE WITH BRINGING THE DRIER AIR
DOWN THE LAST COUPLE DAYS THOUGH. GIVEN THE LACK OF FOCUS FOR LIFT
AND FORECASTED LOWER MOISTURE LEVELS THE COVERAGE OF SHOWERS AND
THUNDERSTORMS SHOULD BE LESS TODAY. MODELS STILL HINTING AT PRECIP
FORMING ALONG THE SEA BREEZE TODAY WHICH SEEMS REASONABLE GIVEN
MOISTURE STILL HANGING AROUND AT COAST. FURTHER NORTH AT KCLL
THOUGH FORECAST SOUNDINGS REVEAL A CAP IN PLACE WHICH SHOULD KEEP
PRECIP LIMITED IN THE NORTHERN ZONES.
THE TROPICAL WAVE CURRENTLY LOCATED NEAR THE YUCATAN IS EXPECTED
TO DRIFT WESTWARDS AND APPROACH NORTHERN MEXICO FRIDAY MORNING.
THE GFS BRINGS THE WAVE AXIS CLOSER TO BROWNSVILLE WHILE THE ECMWF
PUSHES THE WAVE FURTHER SOUTH. AS THE WAVE MOVES WESTWARD THE 500
MB RIDGE WILL BE PUSHING EASTWARD AS AN UPPER LEVEL LOW MOVES
INTO THE PACIFIC NORTHWEST. THE RIDGE WILL PRODUCE A GRADIENT OF
MOISTURE AS CAN BE SEEN IN THE GFS PWAT FIELD. FORECASTED PWATS
OF AROUND 1.00" CAN BE FOUND AT KFWD WHILE AROUND 2.00" AT KCRP.
HOWEVER THIS SHARP GRADIENT SETS UP WILL DETERMINE HOW THE PRECIP
FIELD SETS UP. AS OF NOW IT LOOKS THAT THE SOUTHERN ZONES WILL GET
SOME RAIN BUT A SLIGHT SOUTHERLY DRIFT OF THE UPPER LEVEL RIDGE
COULD EASILY CHANGE THIS.
BY TUESDAY THE UPPER LEVEL RIDGE CONTINUES TO PUSH EASTWARD
ALLOWING ANOTHER TROPICAL WAVE TO WORK ITS WAY INTO SOUTHEAST
TEXAS. THE POSITION OF THE RIDGE WILL AGAIN HELP DETERMINE THE
PRECIP FIELD. THE GFS SHOWS A STRONGER AND MORE PROGRESSIVE UPPER
LEVEL RIDGE WHILE THE ECMWF IS SLIGHTLY SLOWER WITH THE BRINGING
THE RIDGE EASTWARD. 23
MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE TODAY WITH
LIGHT ONSHORE WINDS EXPECTED. A SERIES OF WEAK EASTERLY WAVES WILL
MOVE INTO MEXICO WITH THE FIRST WEAKER WAVE MOVING TOWARD THE
MEXICAN COAST ON FRIDAY AND A SECOND STRONGER WAVE MOVING INLAND ON
SUNDAY. WINDS OVER THE GULF WILL BRIEFLY INCREASE AS THESE WAVES
MOVE INLAND BUT THE STRONGER SUSTAINED WINDS SHOULD REMAIN SOUTH OF
THE COASTAL WATERS. UNSETTLED WEATHER WITH PERIODS OF SHOWERS AND
THUNDERSTORMS WILL PERSIST OVER THE MARINE AREAS THROUGH THE
WEEKEND. WINDS/SEAS OBVIOUSLY HIGHER NEAR STORMS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 98 75 98 / 20 10 20 10 20
HOUSTON (IAH) 99 76 97 76 96 / 30 10 20 10 20
GALVESTON (GLS) 90 81 90 80 89 / 20 20 30 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS SPOKANE WA
258 PM PDT Wed Sep 4 2013
.SYNOPSIS...
Showers and thunderstorms will increase over the Inland Northwest
tonight into Thursday as a Pacific low pressure system approaches
the region. Some storms could be severe especially on Thursday.
Heavy rainfall will also be a concern especially for burn scar
areas along the East Slopes of the Cascades. The low pressure
system will move across the region on Friday and through the
weekend, resulting in much cooler temperatures with continued
showers and a chance for mountain thunderstorms. A significant
drying and warming trend is expected after Monday through much of
the upcoming week.
&&
.DISCUSSION...
Tonight: The moist southerly flow will continue over the Inland
Northwest. Afternoon and early evening convection will be limited
to the higher terrain of the northern mountains and the Blue
mountains where we can expect the surface based convection to
develop. Not much in a way of a trigger to fire off the
convection, despite our building low level instability. The GFS
and NAM are having issues on grasping the small scale features to
ignite the convection, and the HRRR seems to indicate not much
will happen during the time of peak heating. The high resolution
NAM does show nocturnal convection tracking north from Oregon and
reaching area late tonight and have adjusted my pops and weather
to that idea. Overnight lows will remain mild as low level
moisture and dewpoints continue to increase. /rfox.
...VERY WET AND STORMY WEATHER PATTERN THROUGH THE END OF THE WORK
WEEK WITH HEAVY, STRONG OUTFLOW WINDS AND HAIL A CONCERN WITH THUNDERSTORMS...
Thursday through Friday night: A deep upper level low pressure
system spinning off the Pac NW coastline will slowly begin to push
into the region. As this system does so, multiple waves of energy
will pivot around with widespread rain showers and thunderstorms
expected. Rain showers with some embedded thunderstorms will be
lingering across the region through Thursday afternoon, mainly
across the northern portions of the forecast area. Looks like we
should see a short break in the storms across the basin in the
afternoon. This is expected to result in some sun breaks across
the basin, which will further destabilize the atmosphere before
the strongest impulse of energy will pivot across OR and into WA
by the evening hours. Models are showing strong upper level
dynamics with this next wave and steep mid level lapse rates of
roughly 7.5 C/KM. Pwats will continue to increase to up over 1.4
inches, which is 200% plus of normal. The 4km NAM simulated radar
reflectivity continues to show a convective system that rapidly
forms in southern WA and expands northward through the evening.
Sounding profiles across the region would support the possibility
for some large hail and strong winds with the thunderstorms that
develop Thursday evening.
A second impulse is expected to move into the region relatively
quickly behind the one for Thursday night pushing in Friday
morning into Friday afternoon. This will result in little relief
of the soaking rain across the region, especially for the northern
mountains and in the Cascades. This second impulse will not see as
strong stability profiles for severe thunderstorms. However, we
will remain in a very moist atmosphere with convective showers and
thunderstorms expected to bring continued heavy rainfall. 36 hour
rainfall totals from Thursday afternoon into Friday evening are
expected to be up around 1-2 inches possible for the northern
mountains over into the Cascades with some locally higher amounts
where multiple thunderstorms pass through. With the barrage of
heavy rainfall possible in the northern mountains over to the
Cascades and onto Waterville Plateau, we decided that we will
expand the Flash Flood Watch to cover all these areas. Recent 2012
and 2013 burn scar will be most susceptible to flash flooding, but
rainfall rates will be high enough for other non burned scared
areas as well; this will be especially so in steeper terrain. Mud
slides and debris flows will also be possible with this event.
Temperatures will trend much colder Thursday into Friday as the
cold upper level low pressure system nudges over the region.
High temperatures on Friday will be 10 to 15 degrees below normal.
/SVH
Saturday through Sunday night...Cooler and unsettled weather will
prevail across the Inland Northwest for the weekend as an upper
level low drifts over the region. Southwest flow around the eastern
flank of the low will place the focus for showers over the eastern half
of the forecast area. Pwats will continue to be in the range of 125
to 175 percent of normal. This deep moisture fetch will bring
wetting rains to much of the forecast area, but especially to the
northeast mountains of WA and the northern panhandle of Idaho. The
main forcing mechanism will come from upper level dynamics in the
base of the trough along with orographics. Models have some weak
surface based instability during the afternoon and evening hours but
this will depend on whether there are any breaks in the overcast. By
Sunday the GFS shows much less areal coverage of showers as it has
the upper low moving east to northwest Montana, placing more stable
air over eastern WA and mainly upslope flow driving the showers in
north ID. The ECMWF is slower moving the low to the east so some
residual showers remain in the forecast for Sunday night, mainly for
the panhandle mountains.
Daytime temperatures will be on the cool side, with most valley
locations in the 70s Saturday, then warming from west to east
Sunday. Overnight low will be mild, due to precipitation and cloud
cover. As the low moves east, more stable northerly flow could allow
for some fog development across the northeast valleys. /Kelch
Monday afternoon through Wednesday night...If the extended models
hold true to their latest solutions, the wet storm system that
will have lingered over the Inland Northwest will have exited the
region. Another ridge looks to rebound once again, although the
exact strength and location is a little more up in the air. While
this will promote a warming and drying trend, the upcoming
rainfall event may tend to keep temperatures from getting too out
of hand during each afternoon. The moist ground will also combine
with afternoon heating for scattered clouds, which would also act
to keep the region from reaching its full afternoon high
potential. Obviously areas that don`t receive as much rainfall
will have a better chance to dry out quicker, and the temperatures
will be higher. But overall, the main change to this portion of
the forecast was to shave off a few degrees from the high
temperatures each day, but keeping with the warm-up through
Wednesday.
Fog may also become an issue each night, at least over the
northern valleys, but possibly reaching further south as well.
While this isn`t included in the wording of the forecast, it is
something that we can fine tune after this weeks rain event. ty
&&
.AVIATION...
18Z TAFS: Moist and unstable southerly flow will continues over
the region. During the afternoon and evening hours surface based
instability will once again create a chance of thunderstorms over
the mountains around the basin and over the eastern basin
threatening the KGEG area sites and KPUW and KLWS. A few of these
storms may be strong or severe with large hail and strong wind
gusts. Then overnight elevated moisture and instability increases
with all areas having a chance for thunderstorms after 09z and
into Thursday morning. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 65 78 56 64 54 70 / 60 80 100 70 40 40
Coeur d`Alene 62 79 57 65 54 70 / 60 80 90 70 40 50
Pullman 62 78 55 66 48 72 / 60 80 90 50 20 20
Lewiston 68 84 61 73 59 80 / 60 80 80 40 20 10
Colville 59 80 58 66 51 74 / 60 80 100 80 70 50
Sandpoint 59 79 56 65 49 69 / 60 80 90 80 50 50
Kellogg 59 79 54 65 51 71 / 60 80 90 70 50 50
Moses Lake 65 80 58 69 54 76 / 70 80 90 60 30 10
Wenatchee 65 75 59 68 56 74 / 70 90 90 70 50 10
Omak 64 78 59 67 55 76 / 60 80 90 90 70 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flash Flood Watch from late tonight through Friday afternoon for
Northern Panhandle.
WA...Flash Flood Watch from late tonight through Friday afternoon for
Northeast Mountains.
Flash Flood Watch from 2 AM PDT Thursday through Friday
afternoon for East Slopes Northern Cascades-Okanogan
Highlands-Okanogan Valley-Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1003 PM CDT THU SEP 5 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 332 PM CDT THU SEP 5 2013
MAIN FORECAST CONCERNS ARE ON HIGH TEMPERATURES ON FRIDAY AND SHOWER
AND THUNDERSTORM CHANCES FRIDAY NIGHT INTO SATURDAY.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED HIGH
PRESSURE CENTERED OVER EASTERN COLORADO WITH A RIDGE EXTENDING NORTH
THROUGH THE DAKOTAS INTO SOUTHERN SASKATCHEWAN. AN UPPER LOW WAS
NOTED JUST OFF OF THE PACIFIC NORTHWEST...WHILE A BROAD TROUGH WAS
IN PLACE OVER EASTERN CANADA. NORTHWEST FLOW ALOFT WAS NOTED OVER
THE UPPER MISSISSIPPI RIVER VALLEY. SEVERAL WEAK EMBEDDED SHORTWAVES
WERE NOTED OVER THE DAKOTAS. THE PRIMARY WAVE WAS LOCATED OVER
WESTERN NORTH DAKOTA...HEADED SOUTHEAST. HIGH PRESSURE WAS
CENTERED OVER THE WESTERN GREAT LAKES WHILE A STATIONARY BOUNDARY
WAS LOCATED OVER THE EASTERN DAKOTAS AND WAS STRETCHING SOUTHEAST
THROUGH CENTRAL IOWA INTO SOUTHERN ILLINOIS.
THE HIGH WILL SLIDE EAST OF THE REGION TONIGHT AS THE SHORTWAVE
APPROACHES FORM THE DAKOTAS/WESTERN MINNESOTA. SOUTHERLY FLOW WILL
INCREASE ON THE BACK SIDE OF THE HIGH USHERING IN A WARMER AND
SLIGHTLY MORE HUMID AIR MASS. 850 MB MOISTURE TRANSPORT INCREASES
ACROSS WESTERN MINNESOTA AND WESTERN IOWA...WHICH SHOULD RESULT IN
THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. THE MOISTURE
TRANSPORT ATTEMPTS TO EDGE INTO NORTHEAST IOWA AND SOUTHEAST
MINNESOTA LATE TONIGHT INTO EARLY FRIDAY MORNING WHICH MAY SUPPORT
AN ISOLATED SHOWER OR THUNDERSTORM. FORECAST SOUNDINGS ARE RATHER
DRY AND WITHOUT A STRONG FORCING MECHANISM HAVE DECIDED TO
MAINTAIN A DRY FORECAST FOR THE OVERNIGHT HOURS. CANNOT RULE OUT
SOME PATCHY VERY SHALLOW FOG IN COULEE AREAS TONIGHT BUT THAT
SHOULD BE THE EXTENT OF IT. THE GRADIENT TIGHTENS OVER THE REGION
TONIGHT AND WINDS FROM 500 TO 1KFT INCREASE TO 16 TO 25KTS...WHICH
SHOULD PROMOTE ENOUGH MIXING TO PREVENT DENSE FOG FORMATION.
FRIDAY WILL BE A WARM AND BREEZY DAY ACROSS THE REGION AHEAD OF A
WEAK COLD FRONT APPROACHING FROM THE NORTHERN PLAINS. PLAN ON
HIGHS RANGING FROM THE LOWER 80S OVER FAR NORTHERN WISCONSIN TO
THE UPPER 80S TO AROUND 90 OVER NORTHEAST IOWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM CDT THU SEP 5 2013
THE FRONT WILL MOVE THROUGH THE FORECAST AREA FRIDAY NIGHT INTO
SATURDAY MORNING BRINGING CHANCES FOR SHOWERS AND STORMS WITH IT.
THERE IS ELEVATED CAPE OVER THE REGION WITH VERY LITTLE TO NO CAP
IN PLACE. LIFTING FROM 800 MB YIELDS NEARLY 700 J/KG CAPE.
ALSO...850 MB MOISTURE TRANSPORT FOCUSES INTO THE AREA SO THERE
SHOULD BE ENOUGH SUPPORT FOR AT LEAST ISOLATED TO SCATTERED
THUNDERSTORMS. THE BEST CHANCES FOR THESE APPEARS TO BE ALONG AND
EAST OF THE MISSISSIPPI RIVER. HIGH PRESSURE GRADUALLY BUILDS INTO
THE AREA LATE SATURDAY AFTERNOON THROUGH SUNDAY. PRECIPITATION
CHANCES WILL SHIFT SOUTHEAST OF THE FORECAST AREA BY LATE SATURDAY
AFTERNOON AS THE HIGHS BUILDS IN. THE HIGH WILL BE CENTERED OVER
LAKE SUPERIOR ON SUNDAY PROVIDING DRY EAST/NORTHEAST FLOW. HAVE
LOWERED DEW POINTS SIGNIFICANTLY ALONG AND NORTHEAST OF THE
INTERSTATE 94 CORRIDOR WHERE DEEP MIXING WILL YIELD AFTERNOON
RELATIVE HUMIDITY VALUES IN THE MID 30S. THE HIGH WILL SLIDE EAST
OF THE REGION SUNDAY NIGHT INTO MONDAY AS A VIGOROUS TROUGH RACES
ACROSS NORTH DAKOTA AND NORTHERN MINNESOTA. VERY WARM IS ADVECTS
NORTHWARD AHEAD OF THIS FEATURE INTO THE FORECAST AREA WITH 925 MB
TEMPERATURES WARMING INTO THE UPPER 20S TO AROUND 30. DECIDED TO
WARM HIGH TEMPERATURES ON MONDAY INTO THE UPPER 80S TO LOWER
90S...CLOSER TO WHAT THE ECMWF IS ADVERTISING. THERE IS THE
POTENTIAL FOR SHOWERS AND STORMS ALONG AND NORTH OF INTERSTATE 90
ON MONDAY SO TEMPERATURES MAY NOT GET THAT WARM ACROSS THESE
AREAS. ZONAL FLOW LOOKS TO SET UP OVER THE REGION ON TUESDAY INTO
TUESDAY NIGHT WITH EMBEDDED SHORTWAVES POSSIBLY GENERATING SOME
SHOWERS AND STORMS OVER THE FORECAST AREA. THE ECMWF IF
ADVERTISING BETTER CHANCES FOR PRECIPITATION ON WEDNESDAY AS A
TROUGH DIVES SOUTH OUT OF CANADA. THE GFS IS NOT NEARLY AS
AGGRESSIVE WITH THIS FEATURE AND BRINGS THE BULK OF THE
PRECIPITATION THROUGH TUESDAY INTO TUESDAY NIGHT WITH THE PASSAGE
OF A COLD FRONT. CONSIDERABLE UNCERTAINTY IN THE FORECAST BEYOND
MONDAY SO CHOSE TO LEAN TOWARD A MODEL CONSENSUS BLEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 1003 PM CDT THU SEP 5 2013
THE MAIN QUESTION FOR OVERNIGHT IS WITH WHETHER ANY MVFR
CONDITIONS WILL DEVELOP ACROSS THE REGION. SKIES ARE MAINLY CLEAR
AT THE MOMENT...BUT SOME SCATTERED 3-4KFT CU HAS STARTED TO
DEVELOP ALONG PORTIONS OF THE MISSISSIPPI RIVER. THE LATEST MODEL
TRENDS CONTINUE TO SHOW THE HIGHEST RH VALUES STAYING TO THE NORTH
AND WEST OF RST OVERNIGHT. WITH THE PRESSURE GRADIENT TIGHTENING
UP OVERNIGHT INTO TOMORROW MORNING...EXPECT THAT THE WINDS WILL BE
STRONG ENOUGH TO KEEP VISIBILITY AT 6SM OR HIGHER. THESE WINDS
WILL CONTINUE TO INCREASE INTO THIS AFTERNOON WITH SOME GUSTS OF
20KTS OR HIGHER...PARTICULARLY AT RST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
633 PM CDT THU SEP 5 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 332 PM CDT THU SEP 5 2013
MAIN FORECAST CONCERNS ARE ON HIGH TEMPERATURES ON FRIDAY AND SHOWER
AND THUNDERSTORM CHANCES FRIDAY NIGHT INTO SATURDAY.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED HIGH
PRESSURE CENTERED OVER EASTERN COLORADO WITH A RIDGE EXTENDING NORTH
THROUGH THE DAKOTAS INTO SOUTHERN SASKATCHEWAN. AN UPPER LOW WAS
NOTED JUST OFF OF THE PACIFIC NORTHWEST...WHILE A BROAD TROUGH WAS
IN PLACE OVER EASTERN CANADA. NORTHWEST FLOW ALOFT WAS NOTED OVER
THE UPPER MISSISSIPPI RIVER VALLEY. SEVERAL WEAK EMBEDDED SHORTWAVES
WERE NOTED OVER THE DAKOTAS. THE PRIMARY WAVE WAS LOCATED OVER
WESTERN NORTH DAKOTA...HEADED SOUTHEAST. HIGH PRESSURE WAS
CENTERED OVER THE WESTERN GREAT LAKES WHILE A STATIONARY BOUNDARY
WAS LOCATED OVER THE EASTERN DAKOTAS AND WAS STRETCHING SOUTHEAST
THROUGH CENTRAL IOWA INTO SOUTHERN ILLINOIS.
THE HIGH WILL SLIDE EAST OF THE REGION TONIGHT AS THE SHORTWAVE
APPROACHES FORM THE DAKOTAS/WESTERN MINNESOTA. SOUTHERLY FLOW WILL
INCREASE ON THE BACK SIDE OF THE HIGH USHERING IN A WARMER AND
SLIGHTLY MORE HUMID AIRMASS. 850 MB MOISTURE TRANSPORT INCREASES
ACROSS WESTERN MINNESOTA AND WESTERN IOWA...WHICH SHOULD RESULT IN
THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. THE MOISTURE
TRANSPORT ATTEMPTS TO EDGE INTO NORTHEAST IOWA AND SOUTHEAST
MINNESOTA LATE TONIGHT INTO EARLY FRIDAY MORNING WHICH MAY SUPPORT
AN ISOLATED SHOWER OR THUNDERSTORM. FORECAST SOUNDINGS ARE RATHER
DRY AND WITHOUT A STRONG FORCING MECHANISM HAVE DECIDED TO
MAINTAIN A DRY FORECAST FOR THE OVERNIGHT HOURS. CANNOT RULE OUT
SOME PATCHY VERY SHALLOW FOG IN COULEE AREAS TONIGHT BUT THAT
SHOULD BE THE EXTENT OF IT. THE GRADIENT TIGHTENS OVER THE REGION
TONIGHT AND WINDS FROM 500 TO 1KFT INCREASE TO 16 TO 25KTS...WHICH
SHOULD PROMOTE ENOUGH MIXING TO PREVENT DENSE FOG FORMATION.
FRIDAY WILL BE A WARM AND BREEZY DAY ACROSS THE REGION AHEAD OF A
WEAK COLD FRONT APPROACHING FROM THE NORTHERN PLAINS. PLAN ON
HIGHS RANGING FROM THE LOWER 80S OVER FAR NORTHERN WISCONSIN TO
THE UPPER 80S TO AROUND 90 OVER NORTHEAST IOWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM CDT THU SEP 5 2013
THE FRONT WILL MOVE THROUGH THE FORECAST AREA FRIDAY NIGHT INTO
SATURDAY MORNING BRINGING CHANCES FOR SHOWERS AND STORMS WITH IT.
THERE IS ELEVATED CAPE OVER THE REGION WITH VERY LITTLE TO NO CAP
IN PLACE. LIFTING FROM 800 MB YIELDS NEARLY 700 J/KG CAPE.
ALSO...850 MB MOISTURE TRANSPORT FOCUSES INTO THE AREA SO THERE
SHOULD BE ENOUGH SUPPORT FOR AT LEAST ISOLATED TO SCATTERED
THUNDERSTORMS. THE BEST CHANCES FOR THESE APPEARS TO BE ALONG AND
EAST OF THE MISSISSIPPI RIVER. HIGH PRESSURE GRADUALLY BUILDS INTO
THE AREA LATE SATURDAY AFTERNOON THROUGH SUNDAY. PRECIPITATION
CHANCES WILL SHIFT SOUTHEAST OF THE FORECAST AREA BY LATE SATURDAY
AFTERNOON AS THE HIGHS BUILDS IN. THE HIGH WILL BE CENTERED OVER
LAKE SUPERIOR ON SUNDAY PROVIDING DRY EAST/NORTHEAST FLOW. HAVE
LOWERED DEW POINTS SIGNIFICANTLY ALONG AND NORTHEAST OF THE
INTERSTATE 94 CORRIDOR WHERE DEEP MIXING WILL YIELD AFTERNOON
RELATIVE HUMIDITY VALUES IN THE MID 30S. THE HIGH WILL SLIDE EAST
OF THE REGION SUNDAY NIGHT INTO MONDAY AS A VIGOROUS TROUGH RACES
ACROSS NORTH DAKOTA AND NORTHERN MINNESOTA. VERY WARM IS ADVECTS
NORTHWARD AHEAD OF THIS FEATURE INTO THE FORECAST AREA WITH 925 MB
TEMPERATURES WARMING INTO THE UPPER 20S TO AROUND 30. DECIDED TO
WARM HIGH TEMPERATURES ON MONDAY INTO THE UPPER 80S TO LOWER
90S...CLOSER TO WHAT THE ECMWF IS ADVERTISING. THERE IS THE
POTENTIAL FOR SHOWERS AND STORMS ALONG AND NORTH OF INTERSTATE 90
ON MONDAY SO TEMPERATURES MAY NOT GET THAT WARM ACROSS THESE
AREAS. ZONAL FLOW LOOKS TO SET UP OVER THE REGION ON TUESDAY INTO
TUESDAY NIGHT WITH EMBEDDED SHORTWAVES POSSIBLY GENERATING SOME
SHOWERS AND STORMS OVER THE FORECAST AREA. THE ECMWF IF
ADVERTISING BETTER CHANCES FOR PRECIPITATION ON WEDNESDAY AS A
TROUGH DIVES SOUTH OUT OF CANADA. THE GFS IS NOT NEARLY AS
AGGRESSIVE WITH THIS FEATURE AND BRINGS THE BULK OF THE
PRECIPITATION THROUGH TUESDAY INTO TUESDAY NIGHT WITH THE PASSAGE
OF A COLD FRONT. CONSIDERABLE UNCERTAINTY IN THE FORECAST BEYOND
MONDAY SO CHOSE TO LEAN TOWARD A MODEL CONSENSUS BLEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 633 PM CDT THU SEP 5 2013
THE MAIN FOCUS INTO TOMORROW IS WITH THE POTENTIAL FOR STRATUS TO
FORM TONIGHT ALONG WITH HOW STRONG THE WINDS WILL BE TOMORROW
AFTERNOON. MVFR STRATUS THAT FORMED EARLIER TODAY HAS COMPLETELY
DIMINISHED THOUGH THAT BATCH OF HIGHER MOISTURE IS STILL IN PLACE
ACROSS PORTIONS OF SOUTHEAST MINNESOTA. THE QUESTION IS WHETHER IT
WILL DEVELOP OVER RST OR NOT. SOME OF THE SHORT TERM FORECAST
MODELS SUGGEST THAT IT WILL FORM JUST TO THE WEST AND LIFT TO THE
NORTH/NORTHEAST AND MISS RST. FOR NOW...HAVE JUST KEPT THE
LOWERING VISIBILITIES THAT COULD OCCUR TOWARD DAYBREAK. WINDS WILL
PICK UP TOMORROW AFTERNOON AHEAD OF A COLD FRONT WITH GUSTS
INCREASING TO AROUND 16 TO 25KTS AT TIMES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
337 PM CDT WED SEP 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 337 PM CDT WED SEP 4 2013
MAIN FORECAST CONCERNS IN THE SHORT TERM ARE ON TEMPERATURES AND
CLOUD COVER TONIGHT INTO THURSDAY MORNING.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED RIDGING
ACROSS ANCHORED OVER THE ROCKIES. TWO UPPER LOWS NOTED...ONE
CENTERED OVER THE EASTERN SHORE OF HUDSON BAY...AND THE OTHER WAS
JUST EDGING INTO THE PACIFIC NORTHWEST. A WEAK COLD FRONT
STRETCHED FROM CENTRAL MINNESOTA ACROSS CENTRAL WISCONSIN EAST
THROUGH NORTHERN LOWER MICHIGAN AND WAS SLOWLY DRIFTING SOUTH.
THERE HAS NOT BEEN ANY PRECIPITATION ASSOCIATED WITH THE FRONT
JUST A SLIGHT INCREASE IN CLOUD COVER.
SURFACE HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA TONIGHT AS
THE COLD FRONT SLIDES SOUTH INTO CENTRAL IOWA AND SOUTHERN ILLINOIS.
THE STRATUS CURRENTLY OVER NORTHERN WISCONSIN...SLIPS SOUTHWEST
TONIGHT. LINGERING MOISTURE CENTERED AROUND 850 MB...WITH AN
ADDITIONAL POCKET LOCATED IN THE 700-450 MB LAYER...MAY BE ENOUGH TO
GENERATE SOME CLOUD COVER TONIGHT OVER NORTHEAST IOWA....SOUTHEAST
MINNESOTA...AND SOUTHWEST WISCONSIN. FORECAST SOUNDINGS SUGGEST THE
LOWER LEVEL MOISTURE WILL DRY OUT AS THE HIGH BUILDS IN. IF THE
CLOUD COVER LINGERS IT WILL HAVE AN IMPACT ON FOG POTENTIAL AND
TEMPERATURES OVERNIGHT. PLAN ON PARTLY CLOUDY TO MOSTLY CLEAR SKIES
TONIGHT WITH LOW TEMPERATURES RANGING FROM THE UPPER 30S TO LOWER 40S
OVER NORTHERN WISCONSIN TO THE MID TO UPPER 50S ACROSS NORTHEAST
IOWA.
HIGH PRESSURE WILL BE IN CONTROL ACROSS THE REGION ON THURSDAY
PROVIDING DRY AND QUIET WEATHER. THE MAIN CONCERN WILL BE ON
AFTERNOON DEWPOINTS...ESPECIALLY CLOSER TO THE CENTER OF THE HIGH
OVER CENTRAL INTO NORTH CENTRAL WISCONSIN. FORECAST SOUNDINGS SHOW
DRY AIR ALOFT WITH DEEP MIXING TO NEARLY 875 MB. LOOKING UPSTREAM
ACROSS UPPER MICHIGAN AND SOUTHERN ONTARIO...DEWPOINTS ARE ONLY IN
THE UPPER 30S TO LOWER 40S AND THIS AIR IS ADVECTING SOUTHWARD. HAVE
LOWERED AFTERNOON DEWPOINTS INTO THE LOWER 40S OVER WEST CENTRAL
THROUGH CENTRAL WISCONSIN WHERE DEEP MIXING SHOULD EASILY YIELD THESE
AFTERNOON VALUES. THIS WOULD PRODUCE RELATIVE HUMIDITY VALUES IN
THE 27 TO 30 PERCENT RANGE. THERE WILL NOT BE MUCH WIND UNDER THE
HIGH WITH WIND MAINLY LIGHT AND VARIABLE AT 5 MPH OR LESS OVER THESE
AREA. OTHERWISE...PLAN ON SKIES RANGING FROM PARTLY TO MOSTLY CLOUDY
OVER SOUTHEAST MINNESOTA INTO NORTHEAST IOWA...TO MOSTLY SUNNY OVER
NORTH CENTRAL WISCONSIN. A WEAK SHORTWAVE LOOKS TO MOVE ACROSS AREAS
ALONG AND WEST OF THE MISSISSIPPI RIVER WITH THE MAIN IMPACT BEING
AN INCREASE IN CLOUD COVER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 337 PM CDT WED SEP 4 2013
THE HIGH WILL SLIDE EAST INTO THE EASTERN GREAT LAKES THURSDAY NIGHT
INTO FRIDAY. A COLD FRONT IS EXPECTED TO PUSH INTO NORTHWEST
MINNESOTA AND EASTERN SOUTH DAKOTA BY FRIDAY AFTERNOON. SOUTHERLY
FLOW WILL INCREASE ACROSS THE AREA ON FRIDAY AS THE FRONT APPROACHES
HELPING TO USHER IN A WARMER AND SLIGHTLY MORE HUMID AIRMASS. 925 MB
TEMPERATURES WARM TO AROUND 25 ACROSS WESTERN AND CENTRAL WISCONSIN
AND TO THE UPPER 20S ACROSS PORTIONS OF NORTHEAST IOWA AND SOUTHEAST
MINNESOTA. HIGH TEMPERATURES ARE EXPECTED TO WARM INTO THE MID
80S...WITH A FEW UPPER 80S POSSIBLE ALONG THE MISSISSIPPI RIVER
VALLEY AND CLOSER TO THE INTERSTATE 35 CORRIDOR. FORECAST MODELS ARE
ADVERTISING A WEAK SHORTWAVE MOVING ACROSS THE EASTERN DAKOTAS AND
PUSHING INTO THE UPPER MISSISSIPPI RIVER VALLEY LATE THURSDAY NIGHT
INTO EARLY FRIDAY MORNING. 850 MB MOISTURE TRANSPORT IS WEAK AND
FOCUSED INTO SOUTHWEST MINNESOTA AND WESTERN IOWA THURSDAY EVENING
THEN ATTEMPTS TO SHIFT EAST INTO THE AREA EARLY FRIDAY MORNING.
THERE ISN/T MUCH UPPER LEVEL SUPPORT FOR PRECIPITATION SO DECIDED TO
MAINTAIN A DRY FORECAST DURING THIS TIMEFRAME. THE FRONT IS EXPECTED
TO PUSH SOUTHEAST FRIDAY NIGHT INTO SATURDAY POSSIBLY INTERACTING
WITH WEAK UPPER LEVEL IMPULSES IN NORTHWEST FLOW ALOFT. THIS WILL
BRING SLIGHT CHANCES FOR SHOWERS AND STORMS TO THE FORECAST AREA
FRIDAY NIGHT INTO SATURDAY. THE PACIFIC NORTHWEST TROUGH FINALLY
MOVES EAST ACROSS THE NORTHERN PLAINS SUNDAY NIGHT THROUGH MONDAY
NIGHT BREAKING DOWN THE PERSISTENT RIDGING OVER THE UPPER MIDWEST.
THIS WILL BRING CHANCES FOR SHOWERS AND STORMS TO THE FORECAST
AREA...ESPECIALLY SUNDAY NIGHT INTO MONDAY NIGHT. WARM SOUTHERLY
FLOW WILL CONTINUE INTO EARLY NEXT WEEK. HIGHS WILL REMAIN WELL
ABOVE NORMAL THROUGH THE WEEKEND WITH SATURDAY LOOKING TO BE THE
WARMEST DAY WITH HIGHS IN THE MID TO UPPER 80S. THE WARM
TEMPERATURES WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1242 PM CDT WED SEP 4 2013
FOCUS IS ON MVFR STRATUS OVER NORTHEAST WISCONSIN...SITUATED
BEHIND A COLD FRONT LOCATED NEAR I-94. THIS COLD FRONT IS SLATED
TO COME THROUGH THE TAF SITES IN THE NEXT FEW HOURS...FOLLOWED BY
A GRADUAL WIND SHIFT THROUGH THE LATE AFTERNOON AND EVENING HOURS
FROM NORTHWEST TO NORTHEAST. VFR CONDITIONS ARE EXPECTED UNTIL THE
WINDS TAKE ON THAT MORE EASTERLY COMPONENT. AT THAT TIME...STRATUS
SHOULD EITHER DEVELOP OR ADVECT IN FROM THE STRATUS CURRENTLY OVER
NORTHEAST WISCONSIN. APPROXIMATE TIMES OF THIS OCCURRING IN THE
TAFS ARE 08Z AT LSE AND 10Z AT RST. THESE MAY NEED TO BE ADJUSTED
PER OBSERVATION AND SATELLITE TRENDS. ADDITIONALLY...CEILINGS
CURRENTLY FORECAST ARE MVFR AT LSE AND IFR AT RST...BUT IT IS
EASILY POSSIBLE THESE COULD END UP 1 OR 2 CATEGORIES LOWER AT
BOTH SITES. THIS TOO NEEDS TO BE MONITORED. LASTLY...CANNOT RULE
OUT SOME FOG FORMING AT RST TOO IF THIS STRATUS DOES INDEED
MANIFEST ITSELF WITH A LOWER CEILING. DAYTIME HEATING PLUS DRY AIR
ADVECTING IN FROM THE NORTH SHOULD HELP SCATTER OUT THE STRATUS BY
16Z THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1233 PM CDT WED SEP 4 2013
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SYNOPSIS...
ISSUED AT 339 AM CDT WED SEP 4 2013
DRY WITH SEASONABLE TEMPERATURES EARLY...THEN BECOME WARMER AND
MORE HUMID AGAIN THIS WEEKEND AND EARLY NEXT WEEK.
THE MAIN BAND OF WESTERLIES WAS ACRS CANADA...AND WL REMAIN SO
THROUGHOUT THE PERIOD. WITHIN IT...LNGWV RIDGE POSN WL BE OVER WRN
CANADA...WITH A TROF IN THE E. A SHOT OF COLD AIR FM NRN CANADA WL
LEAD TO SOME AMPLIFICATION OF THE ERN TROF EARLY...THEN THE TEND
SHOULD BE FOR A GRADUAL FLATTENING OF THE FLOW. MEANWHILE ACRS THE
CONUS...THE LARGE SCALE WL BE DOMINATED BY SPRAWLING ANTICYCLONE
CURRENTLY CENTERED OVER THE CEN/SRN ROCKIES AND HIGH PLAINS. A
CLOSED UPR LOW OFF THE PAC NW COAST WL EVENTUALLY START TO WORK
ITS WAY E. THAT WL PROBABLY CAUSE THE UPR HIGH TO SHIFT E TOWARD
THE MISSISSIPPI VALLEY LATE IN THE WEEKEND AND NEXT WEEK.
OVERALL...THIS IS A PRETTY TYPICAL UPR PATTERN FOR EARLY AUTUMN.
THE NWLY UPR FLOW ALONG THE SRN EDGE OF THE WESTERLIES WL BE STG
ENOUGH TO SUPPRESS THE VERY WARM/HUMID AIR S OF THE FCST AREA FOR
THE FIRST PART OF THE FCST PERIOD...BUT AS THE FLOW DEAMPLIFIES
AND THE UPR HIGH SHIFTS E...SOME HEAT AND HUMIDITY WL PROBABLY
RETURN TO THE AREA. THE TEMPERATURE ROLLER COASTER WL CONT AT THE
START OF THE FCST PERIOD...WITH WARMER AIR ACRS THE AREA TDA
REPLACED BY COOLER CONDITIONS FOR THE NEXT COUPLE DAYS. THEN TEMPS
SHOULD HEAD BACK TO ABV NORMAL LEVELS BY THE WEEKEND AND WL
PROBABLY STAY THERE NEXT WK. HUMIDITIES WL ALSO BE ON THE
INCREASE. DRY WX WL CONT FOR A FEW MORE DAYS...THEN PCPN CHCS WL
RETURN ONCE THE HEAT AND HUMIDITIY DOES.
&&
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 339 AM CDT WED SEP 4 2013
OVERALLY A PRETTY QUIET PERIOD...THOUGH LOTS OF FCST DETAILS TO
SORT OUT. WELL DEFINED COLD FRONT WAS SURGING SWD ACRS THE LAKE
SUPERIOR RGN EARLY THIS MORNING. WAA/MIXING WITH TIGHTENING
PRESSURE GRADIENT WAS CAUSING TEMPS TO RISE AHEAD OF THE FRONT
DESPITE IT BEING NIGHTTIME...WITH SXHW3 ACTUALLY UP TO 72 F AT ONE
POINT. MODELS WERE TURNING THE SFC WINDS NW AHEAD OF THE ACTUAL
FRONT...AND THUS SEEMED TO BE HAVING TROUBLE MAINTAINING THE
IDENTIFY OF THE FRONT. THE RAP SEEMS TO BE HANDLING THE SITN ABOUT
THE BEST. DESPITE AN ANTICIPATED STG SWD PUSH OF THE FRONT /THERE
ARE CURRENTLY 5 MB 3-HR PRESSURE RISES ON ERN LAKE SUPERIOR/
CURRENT POSN OF THE FRONT SUGGESTS DELAYING ITS ARRIVAL A BIT.
THAT SHOULD ALLOW TEMPS ACRS THE SRN PART OF THE FCST AREA TO WARM
QUICKLY THIS MORNING. RAISED MAXES THERE.
FRONT WL SURGE SWD DOWN THE BAY/LAKESHORE...BUT MAY SLOW OVER THE
SW PART OF THE FCST AREA. SOME LOW-LEVEL MOISTURE IS POOLED ALONG
THE BOUNDARY BACK TO THE W. THAT WL PROBABLY MAKE IT INTO CENTRAL
WI MID-DAY. GIVEN THE CONVERGENCE ALONG THE FRONT...STARTING TO
HAVE CONCERNS THAT AN ISOLD SHRA/TSRA COULD DEVELOP OVER THE SW
CORNER OF THE FCST AREA THIS AFTN. NOT ENOUGH SUPPORT TO ADD TO
THE FCST YET...BUT TRENDED POPS UP TO SILENT 14/S OVER THE SW.
COOLER AND DRIER AIR WITH CANADIAN HIGH WL BECOME ESTABLISHED
ACRS THE AREA TNGT. COULD SEE A FEW CLDS COME OFF THE BAY LATE.
OTHERWISE...EXPECT MAINLY CLR SKIES. WITH WINDS LIKELY DYING OFF
LATE TNGT ACRS THE N...EXPECT THE TYPICAL COLD SPOTS TO DROP INTO
THE 30S. PATCHY FROST IS POSSIBLE IN THESE AREAS BY MORNING.
PLENTY OF SUN IS EXPECTED THU AS HIGH PRESSURE DOMINATES. ELY
FLOW WL KEEP THE LAKESHORE A LITTLE COOLER...BUT DRY AIR SHOULD
ALLOW FOR TEMPS AT MOST LOCATIONS TO REACH AOA NORMAL LEVELS
DESPITE THE CHILLY START TO THE DAY IN THE N.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 339 AM CDT WED SEP 4 2013
NORTHWEST FLOW WILL CONTINUE INTO THE WEEKEND AS 500MB RIDGE
REMAINS ANCHORED ACROSS THE CENTRAL PLAINS. THE 500MB RIDGE SHOULD
SHIFT EAST EARLY NEXT WEEK...THEN BREAK DOWN AS UPPER TROUGH
SWINGS ACROSS THE NORTHERN UNITED STATES. BEYOND THE FORECAST
PERIOD...500MB RIDGE IS EXPECTED TO BUILD ACROSS THE WESTERN
UNITED STATES WITH A NORTHWEST FLOW PATTERN TO BE REESTABLISHED
ACROSS THE WESTERN LAKES.
MODELS CONTINUE TO STRUGGLE AMONGST THEMSELVES AND FROM MODEL RUN
TO RUN ON WHERE TO FOCUS PRECIPITATION THURSDAY NIGHT INTO FRIDAY.
THIS IS ESPECIALLY TRUE FOR THE ECMWF...WHICH TYPICALLY TRENDS
BETTER IN THE MID RANGE PERIOD OF THE FORECAST. THUS CONFIDENCE
IS LOW IN WHEN AND WHERE TO PLACE HIGHEST CHANCES FOR RAIN
THURSDAY NIGHT THROUGH SUNDAY.
IT APPEARS THERE IS A BETTER CHANCE OF SHOWERS AND STORMS AT TIMES
SUNDAY NIGHT THROUGH TUESDAY NIGHT DEPENDING ON WHERE FRONTAL
BOUNDARY ACTUALLY SETS UP. COULD BE A FEW ROUNDS OF SHOWERS AND
STORMS WITH LOCALLY HEAVY RAIN...ASSUMING FIRST ROUND OR TWO OF
SHOWERS AND STORMS DOES NOT PUSH THE BOUNDARY FURTHER SOUTH.
PLENTY OF TIME TO WATCH THIS UNFOLD.
PREVIOUS SHIFT LOWERED MAXIMUM TEMPERATURES ON MONDAY AND THIS
STILL SEEMS REASONABLE. MAY NEED TO COOL IT DOWN EVEN A FEW MORE
DEGREES DUE TO CLOUD COVER AND EXPECTED RAIN FROM AN APPROACHING
WARM FRONT. HIGHS ON TUESDAY AND WEDNESDAY WILL BE DETERMINED BY
HOW MUCH SUN/LACK OF RAIN THAT OCCURS DURING THE DAY AND WHERE
WARM FRONT SETS UP.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1232 PM CDT WED SEP 4 2013
CDFNT TO CONT DROPPING SOUTH INTO SRN WI THIS
AFTERNOON AND INTO NRN IL TNGT. MAIN FCST ISSUE FOR AVIATION
PURPOSES WL BE THE NARROW AREA OF LOW CLOUDS LOCATED BEHIND THE
FNT. VSBL SATL IMAGERY SHOWED THIS CLOUD BAND THINNING OUT AS
DAYTIME MIXING TAKING PLACE. HOWEVER...AS COOLING OCCURS TNGT...
SUBSIDENCE INVERSION WL SHARPEN AND ALLOW FOR A STRATUS FIELD TO
DEVELOP. UNKNOWN QUESTION IS EXACTLY WHERE THESE CLOUDS WOULD
REFORM AS BASES WOULD BE AT LEAST MVFR IF NOT IFR AT SUNRISE.
BEST GUESS RIGHT NOW WOULD BE OVER THE SRN THIRD OF WI IMMEDIATELY
BEHIND THE FRONT. BELIEVE THAT MOST OF NE WI WL REMAIN VFR FOR
TNGT AND THU AS AN AREA OF HI PRES BUILDS INTO THE REGION.
&&
.MARINE...
ISSUED AT 339 AM CDT WED SEP 4 2013
W/SW WINDS EARLY TDA WL SHIFT TO THE NNE AS A SHARP COLD FRONT
SURGES SWD DOWN LAKE MICHIGAN AND THE BAY OF GREEN BAY. GUSTS ABV
25 KTS ARE LIKELY WITH THE FROPA AND FOR A COUPLE HRS AFTERWARD...
THEN WINDS SHOULD BEGIN TO SETTLE BACK DOWN. DURATION PROBABLY
WON/T BE SUFFICIENT TO DRIVE WAVES ABV 4 FT...THOUGH IT COULD GET
VERY CHOPPY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ECKBERG
AVIATION.......AK
MARINE.........SKOWRONSKI
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 339 AM CDT WED SEP 4 2013
DRY WITH SEASONABLE TEMPERATURES EARLY...THEN BECOME WARMER AND
MORE HUMID AGAIN THIS WEEKEND AND EARLY NEXT WEEK.
THE MAIN BAND OF WESTERLIES WAS ACRS CANADA...AND WL REMAIN SO
THROUGHOUT THE PERIOD. WITHIN IT...LNGWV RIDGE POSN WL BE OVER WRN
CANADA...WITH A TROF IN THE E. A SHOT OF COLD AIR FM NRN CANADA WL
LEAD TO SOME AMPLIFICATION OF THE ERN TROF EARLY...THEN THE TEND
SHOULD BE FOR A GRADUAL FLATTENING OF THE FLOW. MEANWHILE ACRS THE
CONUS...THE LARGE SCALE WL BE DOMINATED BY SPRAWLING ANTICYCLONE
CURRENTLY CENTERED OVER THE CEN/SRN ROCKIES AND HIGH PLAINS. A
CLOSED UPR LOW OFF THE PAC NW COAST WL EVENTUALLY START TO WORK
ITS WAY E. THAT WL PROBABLY CAUSE THE UPR HIGH TO SHIFT E TOWARD
THE MISSISSIPPI VALLEY LATE IN THE WEEKEND AND NEXT WEEK.
OVERALL...THIS IS A PRETTY TYPICAL UPR PATTERN FOR EARLY AUTUMN.
THE NWLY UPR FLOW ALONG THE SRN EDGE OF THE WESTERLIES WL BE STG
ENOUGH TO SUPPRESS THE VERY WARM/HUMID AIR S OF THE FCST AREA FOR
THE FIRST PART OF THE FCST PERIOD...BUT AS THE FLOW DEAMPLIFIES
AND THE UPR HIGH SHIFTS E...SOME HEAT AND HUMIDITY WL PROBABLY
RETURN TO THE AREA. THE TEMPERATURE ROLLER COASTER WL CONT AT THE
START OF THE FCST PERIOD...WITH WARMER AIR ACRS THE AREA TDA
REPLACED BY COOLER CONDITIONS FOR THE NEXT COUPLE DAYS. THEN TEMPS
SHOULD HEAD BACK TO ABV NORMAL LEVELS BY THE WEEKEND AND WL
PROBABLY STAY THERE NEXT WK. HUMIDITIES WL ALSO BE ON THE
INCREASE. DRY WX WL CONT FOR A FEW MORE DAYS...THEN PCPN CHCS WL
RETURN ONCE THE HEAT AND HUMIDITIY DOES.
&&
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 339 AM CDT WED SEP 4 2013
OVERALLY A PRETTY QUIET PERIOD...THOUGH LOTS OF FCST DETAILS TO
SORT OUT. WELL DEFINED COLD FRONT WAS SURGING SWD ACRS THE LAKE
SUPERIOR RGN EARLY THIS MORNING. WAA/MIXING WITH TIGHTENING
PRESSURE GRADIENT WAS CAUSING TEMPS TO RISE AHEAD OF THE FRONT
DESPITE IT BEING NIGHTTIME...WITH SXHW3 ACTUALLY UP TO 72 F AT ONE
POINT. MODELS WERE TURNING THE SFC WINDS NW AHEAD OF THE ACTUAL
FRONT...AND THUS SEEMED TO BE HAVING TROUBLE MAINTAINING THE
IDENTIFY OF THE FRONT. THE RAP SEEMS TO BE HANDLING THE SITN ABOUT
THE BEST. DESPITE AN ANTICIPATED STG SWD PUSH OF THE FRONT /THERE
ARE CURRENTLY 5 MB 3-HR PRESSURE RISES ON ERN LAKE SUPERIOR/
CURRENT POSN OF THE FRONT SUGGESTS DELAYING ITS ARRIVAL A BIT.
THAT SHOULD ALLOW TEMPS ACRS THE SRN PART OF THE FCST AREA TO WARM
QUICKLY THIS MORNING. RAISED MAXES THERE.
FRONT WL SURGE SWD DOWN THE BAY/LAKESHORE...BUT MAY SLOW OVER THE
SW PART OF THE FCST AREA. SOME LOW-LEVEL MOISTURE IS POOLED ALONG
THE BOUNDARY BACK TO THE W. THAT WL PROBABLY MAKE IT INTO CENTRAL
WI MID-DAY. GIVEN THE CONVERGENCE ALONG THE FRONT...STARTING TO
HAVE CONCERNS THAT AN ISOLD SHRA/TSRA COULD DEVELOP OVER THE SW
CORNER OF THE FCST AREA THIS AFTN. NOT ENOUGH SUPPORT TO ADD TO
THE FCST YET...BUT TRENDED POPS UP TO SILENT 14/S OVER THE SW.
COOLER AND DRIER AIR WITH CANADIAN HIGH WL BECOME ESTABLISHED
ACRS THE AREA TNGT. COULD SEE A FEW CLDS COME OFF THE BAY LATE.
OTHERWISE...EXPECT MAINLY CLR SKIES. WITH WINDS LIKELY DYING OFF
LATE TNGT ACRS THE N...EXPECT THE TYPICAL COLD SPOTS TO DROP INTO
THE 30S. PATCHY FROST IS POSSIBLE IN THESE AREAS BY MORNING.
PLENTY OF SUN IS EXPECTED THU AS HIGH PRESSURE DOMINATES. ELY
FLOW WL KEEP THE LAKESHORE A LITTLE COOLER...BUT DRY AIR SHOULD
ALLOW FOR TEMPS AT MOST LOCATIONS TO REACH AOA NORMAL LEVELS
DESPITE THE CHILLY START TO THE DAY IN THE N.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 339 AM CDT WED SEP 4 2013
NORTHWEST FLOW WILL CONTINUE INTO THE WEEKEND AS 500MB RIDGE
REMAINS ANCHORED ACROSS THE CENTRAL PLAINS. THE 500MB RIDGE SHOULD
SHIFT EAST EARLY NEXT WEEK...THEN BREAK DOWN AS UPPER TROUGH
SWINGS ACROSS THE NORTHERN UNITED STATES. BEYOND THE FORECAST
PERIOD...500MB RIDGE IS EXPECTED TO BUILD ACROSS THE WESTERN
UNITED STATES WITH A NORTHWEST FLOW PATTERN TO BE REESTABLISHED
ACROSS THE WESTERN LAKES.
MODELS CONTINUE TO STRUGGLE AMONGST THEMSELVES AND FROM MODEL RUN
TO RUN ON WHERE TO FOCUS PRECIPITATION THURSDAY NIGHT INTO FRIDAY.
THIS IS ESPECIALLY TRUE FOR THE ECMWF...WHICH TYPICALLY TRENDS
BETTER IN THE MID RANGE PERIOD OF THE FORECAST. THUS CONFIDENCE
IS LOW IN WHEN AND WHERE TO PLACE HIGHEST CHANCES FOR RAIN
THURSDAY NIGHT THROUGH SUNDAY.
IT APPEARS THERE IS A BETTER CHANCE OF SHOWERS AND STORMS AT TIMES
SUNDAY NIGHT THROUGH TUESDAY NIGHT DEPENDING ON WHERE FRONTAL
BOUNDARY ACTUALLY SETS UP. COULD BE A FEW ROUNDS OF SHOWERS AND
STORMS WITH LOCALLY HEAVY RAIN...ASSUMING FIRST ROUND OR TWO OF
SHOWERS AND STORMS DOES NOT PUSH THE BOUNDARY FURTHER SOUTH.
PLENTY OF TIME TO WATCH THIS UNFOLD.
PREVIOUS SHIFT LOWERED MAXIMUM TEMPERATURES ON MONDAY AND THIS
STILL SEEMS REASONABLE. MAY NEED TO COOL IT DOWN EVEN A FEW MORE
DEGREES DUE TO CLOUD COVER AND EXPECTED RAIN FROM AN APPROACHING
WARM FRONT. HIGHS ON TUESDAY AND WEDNESDAY WILL BE DETERMINED BY
HOW MUCH SUN/LACK OF RAIN THAT OCCURS DURING THE DAY AND WHERE
WARM FRONT SETS UP.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 339 AM CDT WED SEP 4 2013
NARROW BAND OF MVFR CIGS COULD BRUSH THE N RIGHT BEHIND THE FRONT
THIS MORNING...BUT THEY SHOULD MIX OUT DURING THE DAY. MVFR CIGS
ALSO POSSIBLE AT GRB LATE TNGT IF CLDS COME OFF THE BAY....AND MAY
NEED TO CARRY THAT AS A TEMPO GROUP FOR LATE TNGT.
&&
.MARINE...
ISSUED AT 339 AM CDT WED SEP 4 2013
W/SW WINDS EARLY TDA WL SHIFT TO THE NNE AS A SHARP COLD FRONT
SURGES SWD DOWN LAKE MICHIGAN AND THE BAY OF GREEN BAY. GUSTS ABV
25 KTS ARE LIKELY WITH THE FROPA AND FOR A COUPLE HRS AFTERWARD...
THEN WINDS SHOULD BEGIN TO SETTLE BACK DOWN. DURATION PROBABLY
WON/T BE SUFFICIENT TO DRIVE WAVES ABV 4 FT...THOUGH IT COULD GET
VERY CHOPPY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ECKBERG
AVIATION.......SKOWRONSKI
MARINE.........SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT TUE SEP 3 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 239 PM CDT TUE SEP 3 2013
..CURRENTLY AS OF 19Z..
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED AN UPPER LOW
JUST OFF THE PACIFIC NORTHWEST COAST...SUBTROPICAL RIDGING FROM
COLORADO INTO ALBERTA...AND TROUGHING FROM HUDSON BAY DOWN ALONG THE
EAST COAST OF THE U.S.. WITHIN THIS TROUGHING...THE MAIN FEATURE OF
NOTE IS A POTENT SHORTWAVE DROPPING THROUGH NORTHERN MANITOBA AND
ONTARIO...WHICH IS REFLECTED AT THE SURFACE BY A COLD FRONT THAT IS
APPROACHING FAR NORTHWEST MN. HIGH PRESSURE AND DRY AIR DOMINATE THE
FORECAST AREA. THE DRY AIR IS REFLECTED WELL ON THE 12Z SOUNDINGS
FROM MPX...GRB AND DVN WITH PRECIPITABLE WATER VALUES AROUND 0.68
INCHES OR 80 PERCENT OF NORMAL. SOME MID AND HIGH CLOUDS HAVE BEEN
SPREADING INTO THE AREA FROM THE DAKOTAS AND MINNESOTA...ASSOCIATED
WITH SOME WEAK 850MB MOISTURE TRANSPORT AHEAD OF THE COLD FRONT...AS
WELL AS WEAK 320K ISENTROPIC LIFT. THE MID AND HIGH CLOUDS ALSO
REFLECT SEPARATION OF WARMTH ACROSS THE UPPER MIDWEST. 12Z SOUNDINGS
FROM BIS AND ABR HAD 925MB TEMPS AROUND 20C...WHEREAS GRB...DVN AND
MPX WERE AROUND 12C.
..HAZARDS..
NONE.
..SYNOPTIC OVERVIEW..
03.12Z MODEL GUIDANCE REMAINS CONSISTENT IN DEVELOPING AN
ANOMALOUSLY DEEP TROUGH OVER THE HUDSON BAY REGION DURING THE NEXT
24 HOURS. THIS TROUGH HELPS PROPEL THE COLD FRONT CURRENTLY DROPPING
INTO NORTHWEST MN THROUGH THE FORECAST AREA DURING THE DAY
WEDNESDAY. CANADIAN HIGH PRESSURE LOOKS TO BUILD INTO NORTHERN MN
AND UPPER MI BEHIND THE FRONT LATE WEDNESDAY.
..DETAILS..
PLENTIFUL DRY AIR IN THE LOW LEVELS OF THE TROPOSPHERE FOR THE NEXT
24 HOURS...COMBINED WITH CAPPING ADVECTING IN AT 800MB AHEAD OF THE
COLD FRONT DROPPING SOUTH WILL HELP TO KEEP CONDITIONS DRY THROUGH
THE SHORT TERM PERIOD. 03.12Z NAM BMJ CONVECTIVE SCHEME GOES OFF
WEDNESDAY AFTERNOON WEST OF THE MISSISSIPPI RIVER...BUT THINK IT IS
REMOVING THE CAPPING WAY TOO QUICK GIVEN THAT THE 03.12Z GFS DEPICTS
160 J/KG OF CIN AT THE SAME TIME.
ALTHOUGH CONDITIONS ARE EXPECTED TO BE DRY...THERE ARE SOME CLOUD
COVER CONCERNS WHICH TIE INTO TEMPERATURES AND POTENTIAL FOR VALLEY
FOG. INDICATIONS ARE THAT THE CURRENT CIRRUS OVER THE FORECAST AREA
WILL CLEAR THE AREA THIS EVENING. THE NEXT BATCH OF MID/HIGH CLOUDS
UPSTREAM OVER SOUTHERN SASKATCHEWAN AND NORTHERN NORTH DAKOTA LOOK
TO MOVE INTO THE AREA LATE TONIGHT AND PERSIST THROUGH MUCH OF
TOMORROW. GOOD RADIATIONAL COOLING CONDITIONS EXIST BETWEEN THE TWO
BATCHES OF CLOUDS...WHICH SHOULD ALLOW TEMPS TO BOTTOM OUT INTO THE
UPPER 40S TO MID 50S. THE INCREASE IN CLOUDS LATE TONIGHT ALONG WITH
MODELS INCREASING 950-975MB WINDS AHEAD OF THE FRONT SHOULD KEEP ANY
VALLEY FOG THAT FORMS TO MOSTLY THE MISSISSIPPI RIVER TRIBUTARIES...
THOUGH CANNOT RULE OUT PATCHES OF FOG IN THE MISSISSIPPI RIVER
VALLEY. 925MB TEMPS ON WEDNESDAY ARE PROGGED TO CLIMB TO 19-24C...
COOLEST OVER TAYLOR COUNTY. THESE READINGS COMBINED WITH SUNSHINE
FILTERING THROUGH THE CLOUDS WILL ALLOW HIGHS TO TOP OUT IN THE
UPPER 70S TO MID 80S. A FEW SPOTS MAY EVEN HIT THE UPPER 80S...
DEPENDING ON THE AMOUNT OF SUN...AND MOST LIKELY TO OCCUR IN THE
WISCONSIN RIVER VALLEY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 239 PM CDT TUE SEP 3 2013
..HAZARDS..
1. HEAT. MODELS ARE HINTING AT A SURGE OF HEAT COMING INTO THE
FORECAST AREA ON SATURDAY. RIGHT NOW IT APPEARS HEAT INDICES WILL
STAY BELOW ADVISORY CRITERIA...THOUGH.
2. STORMS. THERE ARE CHANCES IN THE FORECAST FOR FRIDAY NIGHT AND
BEYOND. IF THERE IS ANY SEVERE POSSIBILITY...IT WOULD COME EARLY
NEXT WEEK...BUT THERE IS STILL PLENTY OF TIME FOR THIS TO CHANGE.
..SYNOPTIC OVERVIEW..
03.12Z ECMWF/GFS/CANADIAN AND ENSEMBLE DATA ALL SUGGEST A SLOW
PROGRESSION EASTWARD OF THE UPPER LEVEL PATTERN DURING THE NEXT 7
DAYS. MUCH OF THIS PROGRESSION HAS TO WAIT UNTIL FRIDAY BECAUSE OF
THE ANOMALOUSLY DEEP TROUGH SET UP OVER THE HUDSON BAY REGION AND
SOUTHEAST CANADA. BY MONDAY...MODELS PROG THAT THE UPPER LOW
CURRENTLY OFF THE PACIFIC NORTHWEST COAST WILL HAVE SLID INLAND INTO
MONTANA...WHILE THE RIDGE AXIS AHEAD OF IT OVER ALBERTA MOVES EAST
TO OVER THE FORECAST AREA. THEN FOR TUESDAY...INDICATIONS ARE THAT
TROUGHING WILL BE CROSSING MANITOBA...SENDING A COLD FRONT TOWARDS
THE AREA. THE CHANGE IN THE UPPER LEVEL PATTERN MEANS THAT BY THE
WEEKEND...WARM AIR ADVECTION WILL BE IN FORCE...BRINGING CONCERNS OF
CAPPING...PRECIPITATION AND POSSIBLY MUGGY CONDITIONS AGAIN.
..DETAILS..
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...DRY CONDITIONS WILL
DOMINATE THIS PERIOD WITH SUBSIDENCE AND DRY AIR IN PLACE...ALONG
WITH HIGH PRESSURE TRACKING SOUTHEAST ACROSS THE WESTERN GREAT LAKES
REGION. SKIES SHOULD CLEAR OUT NORTH TO SOUTH WEDNESDAY NIGHT AS THE
UPPER FLOW TURNS A BIT MORE NORTHERLY...FOLLOWED BY FULL SUN ON
THURSDAY AND SOME INCREASE IN WARM ADVECTION MID/HIGH CLOUDS LATE
THURSDAY NIGHT. VALLEY FOG CONCERNS...AT LEAST IN THE MISSISSIPPI
RIVER...SHOULD BE MINIMIZED BY POTENTIAL ISSUES WITH CLOUDS AND AN
EASTERLY BREEZE RIGHT ABOVE THE SURFACE. LOWS WILL ALSO BE ON THE
COOL SIDE...ESPECIALLY IN WISCONSIN WHERE THE HIGH TRACKS ACROSS.
HIGHS ON THURSDAY SHOULD BE A LITTLE COOLER THAN WEDNESDAY DUE TO
925MB TEMPS TOPPING OUT BETWEEN 18-22C.
FRIDAY THROUGH TUESDAY...FOCUS IS ON THE WARM ADVECTION PATTERN THAT
DEVELOPS.
1. TEMPERATURES...850MB ANOMALIES ARE PROGGED BETWEEN 0.5-1 ABOVE ON
FRIDAY AND SUNDAY...AND 1.5-2 ABOVE FOR SATURDAY...MONDAY AND
TUESDAY. THESE WILL KEEP US BELOW RECORDS BUT ABOVE TO WELL ABOVE
NORMAL NONETHELESS. 925MB TEMPS CLIMB TO 22-26C ON FRIDAY...24-29C
ON SATURDAY...COOL TO 18-21C ON SUNDAY AND MONDAY AND CLIMB BACK UP
TO 24-29C ON TUESDAY. THE WARMEST READINGS ARE SUGGESTED OVER
NORTHEAST IOWA. MEANWHILE...THE COOLEST READINGS ARE PROGGED OVER
TAYLOR/CLARK COUNTIES WHICH ARE CLOSER TO A CANADIAN HIGH TRACKING
ACROSS SOUTH CENTRAL CANADA AND THE UPPER GREAT LAKES.
2. MUGGY-NESS...GULF OF MEXICO MOISTURE WILL RETURN BACK INTO THE
REGION BUT ITS GOING TO TAKE SOME TIME DUE TO THE CANADIAN HIGH
MOVING ACROSS ON THURSDAY. ADDITIONALLY...THE DROUGHT CONDITIONS
THAT HAVE DEVELOPED WILL HELP TO MIX OUT THIS MOISTURE. THE BETTER
SHOT FOR MORE MUGGY CONDITIONS LOOKS TO COME THIS THE WEEKEND INTO
EARLY NEXT WEEK AS MOISTURE POOLS ALONG A FRONTAL BOUNDARY PROGGED
TO SET UP NEAR THE FORECAST AREA. EVEN STILL...DEWPOINTS DO NOT
APPEAR AS HIGH AS THEY WERE DURING THE HEAT WAVE LAST WEEK.
3. PRECIPITATION CHANCES...MODELS ARE IN GOOD AGREEMENT HOLDING
FRIDAY DRY. THERE COULD BE SOME ELEVATED CONVECTION ON THE EDGE OF
THE WARM SURGE / CAPPING OVER WISCONSIN FRIDAY NIGHT AND SATURDAY...
AND HAVE 20-30 PERCENT CHANCES FOR THEM. FROM SATURDAY NIGHT
ONWARDS...ALL BETS ARE OFF WITH THE 03.12Z ECMWF/CANADIAN/GFS ALL
SHOWING PERIODS OF PRECIPITATION. VERY HARD TO PIN THESE
DOWN...GIVEN FRONTAL BOUNDARY POSITION UNCERTAINTY. ADDITIONALLY...
THE IMPACT OF THE DROUGHT COULD END UP LIMITING THE AMOUNT OF
PRECIPITATION...PARTICULARLY IN THE DAYTIME. FOR NOW FOLLOWED A
MODEL CONSENSUS OF GENERALLY 20-40 PERCENT CHANCES EVERY 12 HOURS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1140 PM CDT TUE SEP 3 2013
THE MAIN FOCUS INTO TOMORROW IS WITH THE POTENTIAL VALLEY FOG
TONIGHT FOLLOWED BY A COLD FRONT PASSAGE TOMORROW MORNING. SKIES
HAVE MAINLY BE CLEAR THIS EVENING WHICH HAS ALLOWED FOR
TEMPERATURES TO QUICKLY DROP OFF WHILE THE DEW POINT HAS COME UP A
BIT. WINDS HAVE BEEN ON THE LIGHT SIDE...EVEN GOING CALM AT TIMES.
SOME OF THE LATEST MODEL GUIDANCE IS SHOWING SOME SLIGHTLY SLOWER
LOW LEVEL WINDS GOING INTO TOMORROW MORNING...SO THE POTENTIAL
SEEMS TO BE A LITTLE HIGHER THAN SOME VALLEY FOG WILL FORM
OVERNIGHT. WINDS ARE STILL BLOWING UP ON THE RIDGE TOPS AT
5-10MPH...SO THAT MAY HOLD BACK THE DEVELOPMENT TO JUST BEFORE
SUNRISE. THIS FOG SHOULD QUICKLY DISSIPATE AS A COLD FRONT MOVES
THROUGH THE REGION AROUND 14Z. WINDS WILL SHIFT AROUND TO THE
NORTHWEST WITH THE MAIN MID LEVEL CLOUD DECK GOING THROUGH EASTERN
WISCONSIN WITH THIS FEATURE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
250 AM MST FRI SEP 6 2013
.SYNOPSIS...A BIT MORE AREAL COVERAGE IN THUNDERSTORMS AS A WEAK
DISTURBANCE ALOFT MOVES ACROSS THE AREA. DEEPER TROPICAL MOISTURE
WILL RETURN TO THE AREA FROM THE SOUTH THIS WEEKEND FOR AN INCREASE
IN SHOWERS AND THUNDERSTORMS BY SUNDAY WITH SHOWERS CONTINUING
THROUGH THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...INFRARED SATELLITE IMAGERY THIS MORNING SHOWED CLEAR
TO PARTLY CLOUDY SKIES ACROSS SRN AZ. PRECIPITABLE WATER VALUES ARE
UP VERSUS 24 HOURS AGO WITH VALUES GENERALLY BETWEEN 1.10"-1.30"
WITH DEEPER MOISTURE ACROSS SRN SONORA MEXICO AND IN THE GULF OF
CALIFORNIA. 2 AM WATER VAPOR IMAGERY SHOWED A WEAK DISTURBANCE SSW
OF EL PASO...MOVING WNW AROUND 20-25 MPH WHICH WOULD PLACE IT NEAR
DOUGLAS AROUND 7 AM AND TUCSON AROUND 11 AM. 06Z NAMDNG5 AND RECENT
RUNS OF HRRR ARE INDICATING A BIT MORE ACTIVE AFTERNOON. THUS HAVE
UPPED POPS THIS AFTERNOON MAINLY ACROSS ERN PIMA/PINAL/SANTA CRUZ
COUNTIES. STILL ON THE DRY SIDE AT THE LOWER ELEVATIONS THUS WILL
SEE LOCALIZED GUSTS UP TO 50 MPH AND CAN`T RULE OUT AREAS OF BLOWING
DUST...ESPECIALLY IN PINAL COUNTY. SHOULD ALSO SEE HIGHLY LOCALIZED
HEAVY RAINERS. STORMS WILL CONTINUE TO ROLL OUT INTO THE LOWER
DESERTS EARLY THIS EVENING. HIGHS TODAY A FEW DEGREES COOLER THAN
THURSDAY.
MAIN THEME FOR THE REMAINDER OF THE FORECAST CYCLE WILL BE WETTER
CONDITIONS AS TROPICAL MOISTURE FROM TS LORENA STREAMS NORTH THIS
WEEKEND WITH CONTINUED FLOW FROM THE SOUTH THROUGH MUCH OF NEXT
WEEK. COULD RUN INTO A PERIOD WHERE SOME PARTS OF THE AREA WILL NEED
TO BE UNDER FLASH FLOOD WATCH...BUT AS DAYSHIFT POINTED OUT
YESTERDAY IT WILL BE HARD TO PINPOINT WHEN THE BEST CHANCES FOR THIS
TO OCCUR. THERE IS THE POTENTIAL THAT RAINFALL OVER THE NEXT WEEK
COULD BE A 2013 MONSOON SAVER FOR SOME SPOTS...WHILE ALSO ADDING TO
THE NEAR RECORD MONSOON RAINFALL THAT SOME AREAS HAVE ALREADY SEEN
THIS MONSOON.
&&
.AVIATION...ISOLATED TO OCCASIONALLY SCT -SHRA/-TSRA DEVELOPING
TODAY AFTER 18Z AND MAINLY CONFINED TO AREAS ALONG THE INTERNATIONAL
BORDER...AS WELL AS MOUNTAINS. SURFACE WIND GENERALLY LIGHT AND FROM
THE EAST OVERNIGHT...BECOMING SOUTHEAST 8-12 KTS THIS AFTERNOON
AFTERNOON...BUT GUSTY AT TIMES...WITH LOCALIZED STRONGER GUSTS FROM
-TSRA POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DRIER AIR WILL GENERALLY LIMIT THUNDERSTORM
POTENTIAL TODAY WITH ONLY ISOLATED COVERAGE EXPECTED. A STRONG
MOISTURE INCREASE FROM THE SOUTH WILL BRING A MUCH BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS BY SUNDAY INTO EARLY NEXT WEEK. IN THE
MEANTIME...GUSTY EASTERLY WINDS OF UP TO 20 MPH CAN BE EXPECTED
TODAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS NEW YORK NY
433 AM EDT FRI SEP 6 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WEAKENS AND SETTLES DIRECTLY OVER THE
REGION TODAY BEFORE SHIFTING SOUTH OF THE AREA THIS AFTERNOON
THROUGH SATURDAY NIGHT. A COLD FRONT WILL PASS THROUGH ON
SUNDAY...FOLLOWED BY HIGH PRESSURE FROM SUNDAY NIGHT THROUGH
WEDNESDAY. A COLD FRONT WILL APPROACH ON THURSDAY...AND PASS
THROUGH THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADIATIONAL COOLING GOING INTO THE EARLY MORNING HOURS WILL ALLOW THE
TEMPERATURES TO DROP WELL INTO THE 40S AND 50S FOR MOST LOCATIONS
WITH A CONTINUED DRYING AIRMASS. WINDS WILL ALSO LOWER AS THE
INFLUENCE OF HIGH PRESSURE IS MORE FELT AS IT DRAWS CLOSER TO THE
AREA.
HIGH PRESSURE WEAKENS AND SETTLES DIRECTLY OVER THE REGION. A
BROAD WEAK UPPER LEVEL TROUGH MOVES ACROSS THE REGION WHICH WILL
BRING SOME CLOUDS BUT THINKING THAT THE SUBSIDENCE IS THE GREATER
FACTOR HERE WITH A MOSTLY SUNNY SKY PREVAILING. THE CENTER OF
HIGH PRESSURE WILL TREND SOUTH OF THE REGION BY THE LATE
AFTERNOON. A WEAK PRESSURE GRADIENT WILL ENABLE FOR LIGHT WINDS
AND THE SYNOPTIC FLOW WILL ENABLE FOR A WEAK SEA BREEZE LATE IN
THE AFTERNOON BUT TEMPERATURES ARE FORECAST TO BE ONLY A FEW
DEGREES ABOVE SEA SURFACE TEMPERATURES.
THE AIRMASS WILL BE SLOW TO MODERATE WITH THE WEAK BOUNDARY LAYER
WINDS DESPITE FORECAST MIXING UP TO AROUND 850MB AND WIND DIRECTION
WILL BE VARIABLE. THIS IS CONVEYED THROUGH THE EVOLUTION OF THE
850MB TEMPERATURE FIELD. THE TEMPS WILL STAY MAINLY BETWEEN 5 AND 7
DEGREES C THROUGH THE DAY. MAX TEMPS LOOKED RELATIVELY SIMILAR
BETWEEN MAV AND MET WITH THE CORRESPONDING NUMERICAL MODEL BUFKIT
SOUNDINGS OF GFS AND NAM SHOWING MIXING JUST BELOW AND ABOVE 850MB
RESPECTIVELY. THERE ARE SIMILAR DIFFERENCES BETWEEN THE RUC AND SREF
SOUNDINGS AS WELL. MAX TEMP FORECAST GENERALLY IN THE UPPER 60S TO
LOWER 70S ACROSS MUCH OF THE FORECAST REGION WHICH WILL BE ABOUT 5
DEGREES BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
FOR TONIGHT...HIGH PRESSURE CONTINUES TO SLOWLY WEAKEN AND MOVE
SOUTH OF THE AREA AS THE UPPER LEVEL TROUGH CONTINUES TO WEAKEN
AND SHIFT WELL EAST OF THE AREA. THIS WILL SET UP A SOUTHWEST WIND
FLOW...WHICH WILL ALLOW FOR SLIGHTLY WARMER LOW TEMPS AND
ESSENTIALLY A MODERATION OF THE AIRMASS. THE 850MB TEMPS ACTUALLY
INCREASE SEVERAL DEGREES DURING THE NIGHT. CLEAR SKIES AND LIGHT
WINDS ESPECIALLY ACROSS THE INTERIOR HOWEVER WILL PROVIDE ANOTHER
GOOD NIGHT OF RADIATIONAL COOLING WHICH WILL OFFSET THE LIGHT
SOUTHWEST FLOW ADVECTING IN WARMER AIR. LOWS WILL BE RELATIVELY
SIMILAR TO THE PREVIOUS NIGHT FOR THE COASTAL AREAS AND URBAN
SECTIONS OF NEW YORK AND NEW JERSEY BUT A FEW DEGREES WARMER
ACROSS THE INTERIOR.
LOWS WERE A BLEND OF MET AND GMOS WITH GREATER WEIGHT FOR MET
GUIDANCE WHICH SHOWS A WIDER RANGE OF TEMPERATURES...WHICH FITS
WELL WITH GOOD RADIATIONAL COOLING.
FOR SATURDAY...HIGH PRESSURE CONTINUES TO WEAKEN AND PUSH SOUTH
OF THE REGION...WITH SOUTHWEST FLOW INCREASING. IN THE UPPER
LEVELS...A NORTHWEST FLOW WILL PREVAIL. TEMPERATURES WILL MAKE A
REBOUND...WITH 850 MB TEMPS INCREASING TO BETWEEN 12 AND 15
DEGREES C AND BOUNDARY LAYER WINDS INCREASE WITH VERTICAL MIXING
UP TO AROUND 900MB. INCREASING CLOUDS WILL START INFILTRATE THE
REGION FROM THE NORTH DURING THE AFTERNOON WELL UPSTREAM OF A
DEEPER SHORTWAVE MOVING INTO ONTARIO. THE HIGHS WERE A BLEND OF
MET AND MAV WITH GREATER WEIGHT TOWARDS THE MET GUIDANCE WHICH
SHOWS GREATER WARMTH ACROSS THE INTERIOR AND COOLER VALUES ALONG
THE COAST. AGAIN...THIS IS SHOWING GREATER RANGE. THIS TIME IT IS
BECAUSE OF THE DOWNSLOPE ACROSS INTERIOR AND MARINE INFLUENCE
ALONG THE COASTAL AREAS. THESE HIGHS WILL BE PRETTY CLOSE TO
NORMAL VALUES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MODELS STILL CLOSELY AGREE ON IDEA OF AN UPPER RIDGE OVER THE PLAINS
STATES AND TROUGH FROM THE MID ATLANTIC INTO EASTERN CANADA TO
START. A VIGOROUS SHORTWAVE WILL DIVE INTO THE BASE OF THE TROUGH ON
SUNDAY...DRIVING A COLD FRONT THROUGH. THIS FRONT WILL BE FOLLOWED
BY A GUSTY NW-N FLOW AS HIGH PRESSURE BUILDS QUICKLY...AND AFTER A
DAY OF NEAR AVG TEMPS ON SUNDAY...A BRIEF COOLER SPELL WILL FOLLOW
FOR SUNDAY NIGHT INTO MON...WITH TEMPS A FEW DEG BELOW AVG.
LOW TEMPS BY MON MORNING COULD APPROACH 40 IN THE COLDEST INTERIOR
VALLEYS AS THE HIGH BUILDS QUICKLY OVERHEAD.
AS THE UPPER TROUGH LIFTS NE WELL INTO NE CANADA...FLOW ALOFT WILL
BECOME MORE ZONAL...ALLOWING THE UPPER HIGH TO BUILD E-WD TO THE MID
ATLC AND SE COASTS AND A WARM FRONT TO PASS WELL TO OUR NORTH ON
TUE. TEMPS SHOULD SLOWLY WARM DURING MID WEEK...RISING TO SLIGHTLY
ABOVE AVG LEVELS WED AND THU. MULTIPLE SHORTWAVES EMBEDDED IN THE
FLOW SHOULD THEN CARVE OUT A NEW ERN TROUGH LATE THIS WEEK...
BRINGING ANOTHER COLD FRONT TOWARD THE AREA LATE IN THE WEEK.
TIMING OF THE FRONT STILL IN QUESTION...WHILE 00Z GFS/ECMWF ARE IN
AGREEMENT ON FROPA BY EARLY THU MORNING...THE 05/12Z ECMWF IDEA OF A
DEEPER UPPER TROUGH AND SLOWER TIMING MAY STILL BE PLAUSIBLE AND
HAVE DELAYED FRONTAL APPROACH UNTIL DAYTIME THU...AND FROPA UNTIL
THU NIGHT...WITH SHOWERS AND POSSIBLE TSTMS.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS TODAY.
VFR THRU THE TAF PERIOD.
LIGHT NORTH TO NORTH-NORTHEAST WINDS ARE EXPECTED THROUGH 12Z.
WINDS THEN VEER TO THE NORTHEAST EARLY TODAY. WINDS THEN WEAKEN AND
SHIFT TO THE SOUTH LATE IN THE AFTERNOON AND TONIGHT.
A WEAK SEA BREEZE IS POSSIBLE ALONG THE IMMEDIATE SOUTH COASTAL
AIRPORTS. AWAY FROM THE COAST...EXPECT LIGHT AND VARIABLE WINDS.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WIND SHIFT
EXPECTED DURING THE AFTERNOON. TIMING MAY BE OFF BY AN HOUR OR TWO.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WIND SHIFT
EXPECTED DURING THE AFTERNOON. TIMING MAY BE OFF BY AN HOUR OR TWO.
KEWR FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WIND SHIFT
EXPECTED DURING THE AFTERNOON. TIMING MAY BE OFF BY AN HOUR OR TWO.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WINDS BECOME
LIGHT AND VARIABLE DURING THE AFTERNOON. TIMING MAY BE OFF BY AN
HOUR OR TWO.
KHPN FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WINDS BECOME
LIGHT AND VARIABLE DURING THE AFTERNOON. TIMING MAY BE OFF BY AN
HOUR OR TWO.
KISP FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WINDS BECOME
LIGHT AND VARIABLE DURING THE AFTERNOON. TIMING MAY BE OFF BY AN
HOUR OR TWO.
OUTLOOK FOR 06Z SAT THROUGH MON...
.FRI NIGHT-SATURDAY NIGHT...VFR.
.SUNDAY...ISOLATED SHOWERS WITH BRIEF MVFR CONDITIONS POSSIBLE.
.SUNDAY NIGHT-TUESDAY...VFR.
&&
.MARINE...
SUB SCA CONDITIONS EXPECTED THROUGH SATURDAY. COLD AIR ADVECTION
OVER THE WARMER WATERS WILL KEEP GUSTS TO 20 KT INTO THIS MORNING
WITH A LOW CHANCE OF ANY 25 KT GUSTS ON THE OCEAN. HOWEVER...WIND
GUSTS WILL THEN SUBSIDE LATE THIS MORNING AND AFTERNOON AS A HIGH
PRESSURE CENTER TO THE WEST MOVES CLOSER TO THE AREA. THE
NORTHERLY WIND FLOW WILL WEAKEN AND BECOME MORE VARIABLE IN
DIRECTION...BEFORE TURNING MORE SOUTHWESTERLY TONIGHT. WINDS WILL
PICK UP MORE ON SATURDAY TO AROUND 10-15 KT IN THE AFTERNOON. SEAS
WILL STAY MAINLY BETWEEN 2 TO 3 FT ON THE OCEAN THROUGH SATURDAY.
SW FLOW AHEAD OF A COLD FRONT ON SUNDAY COULD BUILD THE OCEAN SEAS
OFF EASTERN LONG ISLAND TO 5 FT. POST-FRONTAL FLOW AS STRONG HIGH
PRESSURE BUILDS QUICKLY IN SHOULD GUST TO 25-30 ON THE OCEAN AND THE
ERN SOUND/BAYS SUNDAY NIGHT AND PERHAPS INTO PART OF MON
MORNING...WITH MAX OCEAN SEAS 6 FT DURING THAT TIME.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE MIDDLE OF
NEXT WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD...THE NEW
YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 HAS BEEN
TEMPORARILY TAKEN OUT OF SERVICE WHILE A SOLUTION IS BEING
FORMULATED.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS RADIO PUBLIC WARNING
SYSTEM DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...GOODMAN
AVIATION...BC
MARINE...GOODMAN/JM
HYDROLOGY...GOODMAN/JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
402 AM EDT FRI SEP 6 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WEAKENS AND SETTLES DIRECTLY OVER THE
REGION TODAY BEFORE SHIFTING SOUTH OF THE AREA THIS AFTERNOON
THROUGH SATURDAY NIGHT. A COLD FRONT WILL PASS THROUGH ON
SUNDAY...FOLLOWED BY HIGH PRESSURE FROM SUNDAY NIGHT THROUGH
WEDNESDAY. A COLD FRONT WILL APPROACH ON THURSDAY...AND PASS
THROUGH THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADIATIONAL COOLING GOING INTO THE EARLY MORNING HOURS WILL ALLOW THE
TEMPERATURES TO DROP WELL INTO THE 40S AND 50S FOR MOST LOCATIONS
WITH A CONTINUED DRYING AIRMASS. WINDS WILL ALSO LOWER AS THE
INFLUENCE OF HIGH PRESSURE IS MORE FELT AS IT DRAWS CLOSER TO THE
AREA.
HIGH PRESSURE WEAKENS AND SETTLES DIRECTLY OVER THE REGION. A
BROAD WEAK UPPER LEVEL TROUGH MOVES ACROSS THE REGION WHICH WILL
BRING SOME CLOUDS BUT THINKING THAT THE SUBSIDENCE IS THE GREATER
FACTOR HERE WITH A MOSTLY SUNNY SKY PREVAILING. THE CENTER OF
HIGH PRESSURE WILL TREND SOUTH OF THE REGION BY THE LATE
AFTERNOON. A WEAK PRESSURE GRADIENT WILL ENABLE FOR LIGHT WINDS
AND THE SYNOPTIC FLOW WILL ENABLE FOR A WEAK SEA BREEZE LATE IN
THE AFTERNOON BUT TEMPERATURES ARE FORECAST TO BE ONLY A FEW
DEGREES ABOVE SEA SURFACE TEMPERATURES.
THE AIRMASS WILL BE SLOW TO MODERATE WITH THE WEAK BOUNDARY LAYER
WINDS DESPITE FORECAST MIXING UP TO AROUND 850MB AND WIND DIRECTION
WILL BE VARIABLE. THIS IS CONVEYED THROUGH THE EVOLUTION OF THE
850MB TEMPERATURE FIELD. THE TEMPS WILL STAY MAINLY BETWEEN 5 AND 7
DEGREES C THROUGH THE DAY. MAX TEMPS LOOKED RELATIVELY SIMILAR
BETWEEN MAV AND MET WITH THE CORRESPONDING NUMERICAL MODEL BUFKIT
SOUNDINGS OF GFS AND NAM SHOWING MIXING JUST BELOW AND ABOVE 850MB
RESPECTIVELY. THERE ARE SIMILAR DIFFERENCES BETWEEN THE RUC AND SREF
SOUNDINGS AS WELL. MAX TEMP FORECAST GENERALLY IN THE UPPER 60S TO
LOWER 70S ACROSS MUCH OF THE FORECAST REGION WHICH WILL BE ABOUT 5
DEGREES BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
FOR TONIGHT...HIGH PRESSURE CONTINUES TO SLOWLY WEAKEN AND MOVE
SOUTH OF THE AREA AS THE UPPER LEVEL TROUGH CONTINUES TO WEAKEN
AND SHIFT WELL EAST OF THE AREA. THIS WILL SET UP A SOUTHWEST WIND
FLOW...WHICH WILL ALLOW FOR SLIGHTLY WARMER LOW TEMPS AND
ESSENTIALLY A MODERATION OF THE AIRMASS. THE 850MB TEMPS ACTUALLY
INCREASE SEVERAL DEGREES DURING THE NIGHT. CLEAR SKIES AND LIGHT
WINDS ESPECIALLY ACROSS THE INTERIOR HOWEVER WILL PROVIDE ANOTHER
GOOD NIGHT OF RADIATIONAL COOLING WHICH WILL OFFSET THE LIGHT
SOUTHWEST FLOW ADVECTING IN WARMER AIR. LOWS WILL BE RELATIVELY
SIMILAR TO THE PREVIOUS NIGHT FOR THE COASTAL AREAS AND URBAN
SECTIONS OF NEW YORK AND NEW JERSEY BUT A FEW DEGREES WARMER
ACROSS THE INTERIOR.
LOWS WERE A BLEND OF MET AND GMOS WITH GREATER WEIGHT FOR MET
GUIDANCE WHICH SHOWS A WIDER RANGE OF TEMPERATURES...WHICH FITS
WELL WITH GOOD RADIATIONAL COOLING.
FOR SATURDAY...HIGH PRESSURE CONTINUES TO WEAKEN AND PUSH SOUTH
OF THE REGION...WITH SOUTHWEST FLOW INCREASING. IN THE UPPER
LEVELS...A NORTHWEST FLOW WILL PREVAIL. TEMPERATURES WILL MAKE A
REBOUND...WITH 850 MB TEMPS INCREASING TO BETWEEN 12 AND 15
DEGREES C AND BOUNDARY LAYER WINDS INCREASE WITH VERTICAL MIXING
UP TO AROUND 900MB. INCREASING CLOUDS WILL START INFILTRATE THE
REGION FROM THE NORTH DURING THE AFTERNOON WELL UPSTREAM OF A
DEEPER SHORTWAVE MOVING INTO ONTARIO. THE HIGHS WERE A BLEND OF
MET AND MAV WITH GREATER WEIGHT TOWARDS THE MET GUIDANCE WHICH
SHOWS GREATER WARMTH ACROSS THE INTERIOR AND COOLER VALUES ALONG
THE COAST. AGAIN...THIS IS SHOWING GREATER RANGE. THIS TIME IT IS
BECAUSE OF THE DOWNSLOPE ACROSS INTERIOR AND MARINE INFLUENCE
ALONG THE COASTAL AREAS. THESE HIGHS WILL BE PRETTY CLOSE TO
NORMAL VALUES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MODELS STILL CLOSELY AGREE ON IDEA OF AN UPPER RIDGE OVER THE PLAINS
STATES AND TROUGH FROM THE MID ATLANTIC INTO EASTERN CANADA TO
START. A VIGOROUS SHORTWAVE WILL DIVE INTO THE BASE OF THE TROUGH ON
SUNDAY...DRIVING A COLD FRONT THROUGH. THIS FRONT WILL BE FOLLOWED
BY A GUSTY NW-N FLOW AS HIGH PRESSURE BUILDS QUICKLY...AND AFTER A
DAY OF NEAR AVG TEMPS ON SUNDAY...A BRIEF COOLER SPELL WILL FOLLOW
FOR SUNDAY NIGHT INTO MON...WITH TEMPS A FEW DEG BELOW AVG.
LOW TEMPS BY MON MORNING COULD APPROACH 40 IN THE COLDEST INTERIOR
VALLEYS AS THE HIGH BUILDS QUICKLY OVERHEAD.
AS THE UPPER TROUGH LIFTS NE WELL INTO NE CANADA...FLOW ALOFT WILL
BECOME MORE ZONAL...ALLOWING THE UPPER HIGH TO BUILD E-WD TO THE MID
ATLC AND SE COASTS AND A WARM FRONT TO PASS WELL TO OUR NORTH ON
TUE. TEMPS SHOULD SLOWLY WARM DURING MID WEEK...RISING TO SLIGHTLY
ABOVE AVG LEVELS WED AND THU. MULTIPLE SHORTWAVES EMBEDDED IN THE
FLOW SHOULD THEN CARVE OUT A NEW ERN TROUGH LATE THIS WEEK...
BRINGING ANOTHER COLD FRONT TOWARD THE AREA LATE IN THE WEEK.
TIMING OF THE FRONT STILL IN QUESTION...WHILE 00Z GFS/ECMWF ARE IN
AGREEMENT ON FROPA BY EARLY THU MORNING...THE 05/12Z ECMWF IDEA OF A
DEEPER UPPER TROUGH AND SLOWER TIMING MAY STILL BE PLAUSIBLE AND
HAVE DELAYED FRONTAL APPROACH UNTIL DAYTIME THU...AND FROPA UNTIL
THU NIGHT...WITH SHOWERS AND POSSIBLE TSTMS.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS TODAY.
VFR THRU THE TAF PERIOD.
LIGHT NORTH TO NORTH-NORTHEAST WINDS ARE EXPECTED THROUGH 12Z.
WINDS THEN VEER TO THE NORTHEAST EARLY FRIDAY. WINDS THEN WEAKEN AND
SHIFT TO THE SOUTH LATE FRIDAY INTO FRIDAY NIGHT.
A WEAK SEA BREEZE IS POSSIBLE ALONG THE IMMEDIATE SOUTH COASTAL
AIRPORTS. AWAY FROM THE COAST...EXPECT LIGHT AND VARIABLE WINDS.
OUTLOOK FOR 06Z SAT THROUGH MON...
.FRI NIGHT-SATURDAY NIGHT...VFR.
.SUNDAY...ISOLATED SHOWERS WITH BRIEF MVFR CONDITIONS POSSIBLE.
.SUNDAY NIGHT-TUESDAY...VFR.
&&
.MARINE...
SUB SCA CONDITIONS EXPECTED THROUGH SATURDAY. COLD AIR ADVECTION
OVER THE WARMER WATERS WILL KEEP GUSTS TO 20 KT INTO THIS MORNING
WITH A LOW CHANCE OF ANY 25 KT GUSTS ON THE OCEAN. HOWEVER...WIND
GUSTS WILL THEN SUBSIDE LATE THIS MORNING AND AFTERNOON AS A HIGH
PRESSURE CENTER TO THE WEST MOVES CLOSER TO THE AREA. THE
NORTHERLY WIND FLOW WILL WEAKEN AND BECOME MORE VARIABLE IN
DIRECTION...BEFORE TURNING MORE SOUTHWESTERLY TONIGHT. WINDS WILL
PICK UP MORE ON SATURDAY TO AROUND 10-15 KT IN THE AFTERNOON. SEAS
WILL STAY MAINLY BETWEEN 2 TO 3 FT ON THE OCEAN THROUGH SATURDAY.
SW FLOW AHEAD OF A COLD FRONT ON SUNDAY COULD BUILD THE OCEAN SEAS
OFF EASTERN LONG ISLAND TO 5 FT. POST-FRONTAL FLOW AS STRONG HIGH
PRESSURE BUILDS QUICKLY IN SHOULD GUST TO 25-30 ON THE OCEAN AND THE
ERN SOUND/BAYS SUNDAY NIGHT AND PERHAPS INTO PART OF MON
MORNING...WITH MAX OCEAN SEAS 6 FT DURING THAT TIME.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE MIDDLE OF
NEXT WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD...THE NEW
YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 HAS BEEN
TEMPORARILY TAKEN OUT OF SERVICE WHILE A SOLUTION IS BEING
FORMULATED.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS RADIO PUBLIC WARNING
SYSTEM DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...GOODMAN
AVIATION...BC
MARINE...GOODMAN/JM
HYDROLOGY...GOODMAN/JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
201 AM EDT FRI SEP 6 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WEAKENS AND SETTLES DIRECTLY OVER THE
REGION TODAY BEFORE SHIFTING SOUTH OF THE AREA THIS AFTERNOON
THROUGH SATURDAY NIGHT. A COLD FRONT MOVES ACROSS THE REGION ON
SUNDAY...FOLLOWED BY ANOTHER AREA OF HIGH PRESSURE FOR THE START
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SLIGHT ADJUSTMENTS FOR TEMPS AND DEWPOINTS WITH OTHERWISE NO
REMARKABLE CHANGES MADE TO THE FORECAST. THE WINDS HAVE STAYED UP
FOR SOME LOCATIONS...PARTICULARLY ACROSS THE COASTAL LOCATIONS
WHICH IS WHERE TEMPS WERE INCREASED SLIGHTLY. THE WIND HAS ACTED
TO MITIGATE RADIATIONAL COOLING.
MOSTLY CLEAR FOR THE REST OF THE NIGHT WITH A COOL CANADIAN
AIRMASS PROVIDING THE TRI-STATE AREA WITH BELOW NORMAL LOW
TEMPERATURES. MIN TEMPS GENERALLY IN THE UPPER 30S TO LOWER 40S
ACROSS THE INTERIOR WITH UPPER 40S TO UPPER 50S THE MIN TEMP RANGE
FOR COASTAL AREAS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
FOR FRIDAY...HIGH PRESSURE WEAKENS AND SETTLES DIRECTLY OVER THE
REGION. A BROAD WEAK UPPER LEVEL TROUGH MOVES ACROSS THE REGION.
THE CENTER OF HIGH PRESSURE WILL TREND SOUTH OF THE REGION BY THE
LATE AFTERNOON. A WEAK PRESSURE GRADIENT WILL ENABLE FOR LIGHT
WINDS AND THE SYNOPTIC FLOW WILL ENABLE FOR A WEAK SEA BREEZE LATE
IN THE AFTERNOON BUT TEMPERATURES ARE FORECAST TO BE ONLY A FEW
DEGREES ABOVE SEA SURFACE TEMPERATURES.
THE AIRMASS WILL BE SLOW TO MODERATE WITH THE WEAK BOUNDARY LAYER
WINDS DESPITE FORECAST MIXING UP TO AROUND 850MB AND WIND DIRECTION
WILL BE VARIABLE. THIS IS CONVEYED THROUGH THE EVOLUTION OF THE
850MB TEMPERATURE FIELD. THE TEMPS WILL STAY MAINLY BETWEEN 5 AND 7
DEGREES C THROUGH THE DAY. MAX TEMPS LOOKED RELATIVELY SIMILAR
BETWEEN MAV AND MET WITH THE CORRESPONDING NUMERICAL MODEL BUFKIT
SOUNDINGS OF GFS AND NAM SHOWING MIXING JUST BELOW AND ABOVE 850MB
RESPECTIVELY. THERE ARE SIMILAR DIFFERENCES BETWEEN THE RUC AND SREF
SOUNDINGS AS WELL. MAX TEMP FORECAST GENERALLY IN THE UPPER 60S TO
LOWER 70S ACROSS MUCH OF THE FORECAST REGION WHICH WILL BE ABOUT 5
DEGREES BELOW NORMAL.
FOR FRIDAY NIGHT...HIGH PRESSURE CONTINUES TO SLOWLY WEAKEN AND
MOVE SOUTH OF THE AREA AS THE UPPER LEVEL TROUGH CONTINUES TO
WEAKEN AND SHIFT WELL EAST OF THE AREA. THIS WILL SET UP A
SOUTHWEST WIND FLOW...WHICH WILL ALLOW FOR SLIGHTLY WARMER LOW
TEMPS AND ESSENTIALLY A MODERATION OF THE AIRMASS. THE 850MB TEMPS
ACTUALLY INCREASE SEVERAL DEGREES DURING THE NIGHT. CLEAR SKIES
AND LIGHT WINDS ESPECIALLY ACROSS THE INTERIOR HOWEVER WILL
PROVIDE ANOTHER GOOD NIGHT OF RADIATIONAL COOLING WHICH WILL
OFFSET THE LIGHT SOUTHWEST FLOW ADVECTING IN WARMER AIR.
FOR SATURDAY...HIGH PRESSURE CONTINUES TO WEAKEN AND PUSH SOUTH
OF THE REGION...WITH SOUTHWEST FLOW INCREASING. IN THE UPPER
LEVELS...A NORTHWEST FLOW WILL PREVAIL. TEMPERATURES WILL MAKE A
REBOUND...WITH 850 MB TEMPS INCREASING TO BETWEEN 12 AND 15
DEGREES C AND BOUNDARY LAYER WINDS INCREASE WITH VERTICAL MIXING
UP TO AROUND 930 TO 900MB.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MODELS IN DECENT AGREEMENT WITH WEAK MEAN UPPER TROUGHING FOR THE
WEEKEND INTO EARLY NEXT WEEK GIVING WAY TO ZONAL TO SLIGHTLY RIDGED
FLOW FOR MID WEEK...BEFORE A STRONGER TROUGH APPROACHES FOR THE END
OF THE WEEK.
FAIR CONDITIONS WITH SEASONABLE TEMPS (UPPER 70S/LOWER 80S) THIS
WEEKEND AS HIGH PRESSURE WEAKENS AND SINKS SE OF THE REGION.
A SHORTWAVE DIGS INTO THE NORTHEAST ON SUNDAY AND THEN EAST SUNDAY
NIGHT...WITH AN ASSOCIATED COLD FRONTAL PASSAGE ON SUN. BEST FORCING
LOOKS TO BE NORTH OF THE REGION...AND WITH LACKING
INSTABILITY...ONLY EXPECTING ISOLATED TO SCATTERED SHOWER ACTIVITY
WITH FRONTAL PASSAGE ON SUNDAY (MAINLY NORTHERN ZONES). BEHIND THE
FRONT...A BRIEF SHOT OF COOL CANADIAN AIR EXPECTED FOR SUNDAY NIGHT
INTO MONDAY.
THEN A GRADUAL MODERATION TO SEASONABLE TO SLIGHTLY ABOVE SEASONABLE
CONDITIONS AND MORE HUMIDITY FOR MID WEEK AS CANADIAN HIGH PRESSURE
SINKS SOUTH OF THE REGION.
MODELS IN DECENT AGREEMENT WITH A STRONGER DIGGING TROUGH
APPROACHING WED INTO THU...WITH AN ASSOCIATED SLOW MOVING FRONTAL
SYSTEM APPROACHING THE REGION. THIS WILL BRING A GRADUALLY
INCREASING POTENTIAL FOR SHRA/TSRA ACTIVITY WED AFT/EVE...AND MORE SO
THU/THU NIGHT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS TODAY.
VFR THRU THE TAF PERIOD.
LIGHT NORTH TO NORTH-NORTHEAST WINDS ARE EXPECTED THROUGH 12Z.
WINDS THEN VEER TO THE NORTHEAST EARLY FRIDAY. WINDS THEN WEAKEN AND
SHIFT TO THE SOUTH LATE FRIDAY INTO FRIDAY NIGHT.
A WEAK SEA BREEZE IS POSSIBLE ALONG THE IMMEDIATE SOUTH COASTAL
AIRPORTS. AWAY FROM THE COAST...EXPECT LIGHT AND VARIABLE WINDS.
OUTLOOK FOR 06Z SAT THROUGH MON...
.FRI NIGHT-SATURDAY NIGHT...VFR.
.SUNDAY...ISOLATED SHOWERS WITH BRIEF MVFR CONDITIONS POSSIBLE.
.SUNDAY NIGHT-TUESDAY...VFR.
&&
.MARINE...
COLD AIR ADVECTION OVER THE WARMER WATERS WILL KEEP GUSTS TO 20 KT
FOR THE REST OF THE OVERNIGHT.
WIND GUSTS SUBSIDE INTO EARLY THIS MORNING AS A HIGH PRESSURE
CENTER TO THE WEST APPROACHES. THE NORTHERLY WIND FLOW WILL WEAKEN
AND MORE VARIABLE IN DIRECTION...BEFORE TURNING MORE SOUTHWESTERLY
TONIGHT.
GENERALLY SUB SCA CONDS THIS WEEKEND THROUGH NEXT WEEK. A COLD
FRONTAL PASSAGE SUNDAY NIGHT MAY HAVE SOME WIND GUSTS APPROACHING
25 KT.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE MIDDLE OF
NEXT WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD...THE NEW
YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 HAS BEEN
TEMPORARILY TAKEN OUT OF SERVICE WHILE A SOLUTION IS BEING
FORMULATED.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS RADIO PUBLIC WARNING
SYSTEM DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JM/JC/NV
NEAR TERM...JM/JC
SHORT TERM...JM
LONG TERM...NV
AVIATION...BC
MARINE...JM/JC/NV
HYDROLOGY...JC/NV
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1151 PM CDT Thu Sep 5 2013
.SHORT TERM...(This Evening through Friday)
Issued at 243 PM CDT THU SEP 5 2013
Upper level high remains centered over Colorado through tomorrow
while a surface high continues to retreat eastward. An area of
isolated showers has continued to move closer to our northern
areas...although most of the precip is not reaching the ground. The
12z NAM supports moisture convergence in this area along with an
axis of slight elevated instability which extends into northeast
Kansas. The HRRR has also been consistent with bringing these
showers into our area. If showers are able to persist within the dry
air and weak advection only northern row of counties look to be
affected the next few hours with an overall diminishing trend
towards the evening.
High temperatures look to reach the low to mid 90s today which is
above normal for this time of year. The skies will remain partly
cloudy especially across northern areas closer to the ongoing shower
activity. Tonight WAA will again set up across eastern Nebraska well
north of the northeast Kansas to keep the entire area dry. Low
temperatures tonight appear to be on track for the mid to upper 60s.
Low level winds will gradually veer allowing warming 850 temps to
spread into eastern KS therefore high temperatures will make it into
the low to mid 90s again tomorrow. With more mixing likely tomorrow
during the day winds will likely increase to around 10 mph with
gusts up to 20 mph possible.
.LONG TERM...(Friday Night through Thursday)
Issued at 243 PM CDT THU SEP 5 2013
The forecast for Friday night through Tuesday is essentially one
of persistence. Other than subtle day to day differences, the
weather pattern will be fairly stagnant through the period with a
large area of upper level high pressure slowly drifting from west
to east across the plains and into the Ohio valley. High
temperatures will be consistently in the 90s. The hottest day
currently appears to be Saturday with southwest surface winds, the
upper ridge almost directly overhead, and the warmest 850 temps of
the week in place all pointing to highs in the middle to upper
90s. There will be a couple of very weak upper disturbances that
may provide enough lift for a shower or thunderstorm, mainly
northeast of the local forecast area along a weak convergence
zone, late on Saturday. Will watch these features in future
forecasts but expect dry conditions for the most part through the
weekend.
There are a couple of stronger northern stream short wave troughs
that come over the top of the ridge next week. The trough crossing
the Dakotas on Monday will push a cold front to the south, but
expect this front to lose its forward progression and stall over
northern Nebraska. The second of the stronger troughs will cross
the Dakotas late Tuesday and should successfully push the cold
front through the forecast area by late Wednesday. Much of the
upper forcing will remain well to the north, and surface
convergence is not expected to be particularly strong, but may be
sufficient for scattered storms along the incoming front. Cooler
and drier air with almost meridional flow aloft will follow the
frontal passage and expect the end of next week to be both cooler
and dry.
&&
.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1151 PM CDT THU SEP 5 2013
With a lack of large scale forcing and the 00Z RAOB still showing
a decent dry slot around 800MB, VFR conditions are expected to
prevail through the day. Lows are expected to remain warm enough
with just enough mixing to preclude any ground fog formation.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 AM EDT FRI SEP 6 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 410 PM EDT THU SEP 5 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE GREAT LAKES BETWEEN A TROUGH OVER NE CANADA AND A RIDGE
FROM COLORADO INTO THE WRN PLAINS. THE MAIN UPSTREAM SHORTWAVE
TROUGH OF INTEREST WAS MOVING INTO WEST CENTRAL SASK. AT THE
SFC...HIGH PRES WAS CENTERED OVER MI AND THE WRN GREAT LAKES
BRINGING CLEAR SKIES AND LIGHT WINDS TO THE REGION.
TONIGHT...MAINLY CLEAR SKIES THIS EVENING ARE EXPECTED TO GIVE WAY
TO INCREASING MID/HIGH CLOUDS LATE. TEMPS MAY DROP OFF QUICKLY AFTER
SUNSET BUT WITH INCREASING SW FLOW OVERNIGHT...TEMPS ARE EXPECTED TO
ONLY DROP TO AROUND CENTRAL 50 AND BECOME STEADY OR SLOWLY RISING IN
THE MID TO UPPER 50S WEST.
FRIDAY...THE SASK SHRTWV IS EXPECTED TO SLIDE JUST NORTH OF LAKE
SUPERIOR. HOWEVER...925-700 MB THETA-E ADVECTION AHEAD OF THIS
FEATURE AND ASSOCIATED 310K ISENTROPIC LIFT WILL SUPPORT SCT ELEVATED
SHRA/TSRA INTO N AND W LAKE SUPERIOR BY LATE MORNING THAT MAY SPREAD
INTO THE CNTRL AND EAST DURING THE AFTERNOON. THERE IS STILL ENOUGH
UNCERTAINTY WITH MDLS DIFFERING ON TIMING/POSITION OF THE PCPN TO
KEEP JUST CHANCE POPS. ALTHOUGH MUCAPE VALUES TO AROUND 1K J/KG
RANGE MAY SUPPORT SOME STRONGER STORMS...THE GREATER INSTABILITY
WITH MLCAPES OF 1000-1500 J/KG IS EXPECTED TO REMAIN UPSTREAM OVER
MN. EVEN WITH INCREASING CLOUDS AND PCPN POSSIBLE DURING THE
AFTERNOON...HIGH TEMPS SHOULD CLIMB INTO THE LOWER 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 410 PM EDT THU SEP 5 2013
MAIN FCST CONCERNS IN THE LONGER TERM REVOLVE ARND POPS ON FRI
NGT/SAT ASSOCIATED WITH PASSAGE OF SHRTWVS IN NW FLOW ALF BTWN THE
MEAN TROF OVER QUEBEC AND RIDGE IN THE PLAINS. FOCUS FOR LATER IN
THE WEEKEND TURNS TOWARD HI PRES BLDG INTO THE UPR LKS.
FRI NGT/SAT...A SHRTWV EMBEDDED IN THE NW FLOW ALF IS PROGGED TO
PASS NEAR THE UPR LKS IN THE EVNG...SO EXPECT THE BEST CHC OF
SHRA/TS TO BE IN THE EVNG WHEN ACCOMPANYING PVA INTERACTS WITH AXIS
OF HIER H85 THETA E. MID LVL DRYING/NEGATIVE H85 THETA E AVCTN IN
THE WAKE OF THIS INITIAL SHRTWV PASSAGE WL THEN RESULT IN
DIMINISHING POPS NW-SE THRU SAT MRNG...BUT APRCH OF ANOTHER SHRTWV
IN THE NW FLOW ALF WARRANTS AT LEAST A SCHC OF LINGERING SHRA. THE
12Z GFS AND ESPECIALLY THE 00Z CNDN MODELS ARE SLOWER/STRONGER THAN
THE BULK OF THE OTHER GUIDANCE WITH THIS TRAILING
DISTURBANCE...LINGERING DEEP LYR QVECTOR CNVGC AND QPF THRU MOST OF
THE DAY ON SAT...SO RETAINED SOME LO CHC POPS ESPECIALLY OVER THE
SCENTRAL THRU THE ENTIRE DAY.
SAT NGT THRU SUN...CNDN HI PRES UNDER CONFLUENT NW FLOW ALF BTWN THE
TROF IN QUEBEC/RDG IN THE PLAINS IS PROGGED TO SHIFT FM MANITOBA AT
00Z SUN TO OVER LK SUP SUN AFTN. UNDER LARGER SCALE SUBSIDENCE AND
PWAT FCST AOB 0.50 INCH...DRY WX WL PREVAIL. THE ONLY CONCERN IS
WHETHER THERE WL BE ANY LO CLDS AT LEAST FOR A TIME NEAR LK SUP WITH
UPSLOPE NNE FLOW UNDER SHARP SUBSIDENCE INVRN H85-9 IN ADVANCE OF
THE INCOMING SFC HI AS SUGGESTED BY THE 06Z AND 12Z GFS RUNS. GIVEN
LARGE SCALE ACYC LLVL FLOW...DRY NATURE OF INCOMING AIRMASS AND
MARGINAL CHILL OF THIS AIRMASS FOR LK CLDS /H925 TEMPS NO LOWER THAN
6-7C OVER THE E HALF COMPARED TO OPEN WATER TEMPS 14-15C/...
RESTRICTED FCST OF SCT-BKN LO CLDS TO THE HIER TERRAIN OF THE
NCENTRAL EARLY SUN MRNG PER THE MORE PESSIMISTIC GFS FCST SDNGS AND
BEFORE DAYTIME HEATING WOULD MIX THESE CLDS OUT ON SUN AFTN. TEMPS
ON SUN MRNG/AFTN WL BE COOLER THAN THE DAY BEFORE WITH H85 TEMPS
FCST BTWN 5-10C DURING THIS PERIOD. EXPECT THE LOWEST MIN TEMPS ON
SUN MRNG OVER THE INTERIOR W...WITH NNE FLOW OFF LK SUP KEEPING
AREAS NEAR THE SHORE WARMER.
SUN NGT...AS SFC HI PRES DRIFTS OVER NY STATE BY 12Z SUN...A RETURN
SLY FLOW OF WARMER/MOISTER AIR BTWN THIS FEATURE AND A SHRTWV/
ACCOMPANYING SFC LO MOVING INTO THE NRN PLAINS WL DVLP OVER THE UPR
LKS. SO EXPECT AT LEAST SOME INCRS IN CLDS AND A WARMER OVERNGT.
RESTRICTED POPS TO THE FAR WRN CWA GIVEN MODEL QPF/LINGERING LLVL
DRY AIR OVER MOST OF THE CWA.
MON INTO TUE...AS SHRTWV IN THE NRN PLAINS AND ATTENDANT SFC LO PRES/
WARM FNT MOVE TOWARD THE UPR LKS...EXPECT SHRA/TS CHCS TO INCRS OVER
THE CWA. NOT SURPRISINGLY...THE EXTENDED MODELS DISAGREE ON THE
EXACT TRACK OF THE SFC LO/WARM FNT AND AXIS OF HIER QPF. THE 12Z AND
ESPECIALLY THE 00Z CNDN MODELS ARE FARTHER N WITH THE SFC LO TRACK/
WARM FNT AND FCSTS THE BULK OF ANY ACCOMPANYING SHRA/TS TO REMAIN N
OF UPR MI WHILE THE 06Z GFS FCSTS HEAVY PCPN WITH THE SFC LO
TRACKING E THRU THE CWA OVER THE WARM FNT ON MON INTO EARLY TUE. THE
RESULT OF THIS SCENARIO WOULD BE A WARM SUMMER-LIKE DAY WITH A GOOD
DEAL OF SUNSHINE AND H85/SFC TEMPS NEAR 20C/WELL INTO THE 80S AWAY
FM LK MODERATION IN LLVL SW FLOW. SHRA/TS WITH HEAVY RA/PSBL SEVERE
TS WOULD BE THE RESULT IF THE GFS MODEL VERIFIES. THE 12Z GFS/00Z
ECWMF RUNS ARE A COMPROMISE BTWN THOSE TWO CAMPS AND ALSO INDICATE
THE POTENTIAL FOR SEVERE TS WITH FCST H85 TEMPS UP TO 20C AND SSI AS
LO AS -3 TO -4C UNDER STRONGER H5 FLOW. GIVEN THESE UNCERTAINTIES...
MAINTAINED CONSENSUS FCST FOR NOW.
EXTENDED...AS AN UPR TROF DEEPENS INTO THE GREAT LKS ON WED BEHIND
DEPARTING SHRTWV RESPONSIBLE FOR THE MON/TUE POPS...EXPECT SHRA/TS
CHCS TO PERSIST. EXPECT COOLER/DRIER WX TO SPREAD TO THE E NEXT
THU/FRI AS HI PRES BLDS TOWARD THE PLAINS/WRN GRT LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 143 AM EDT FRI SEP 6 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS EARLY THIS MORNING WITH MID
CLOUDS THICKENING AT CMX. ANY SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO HOLD OFF UNTIL THIS AFTERNOON. THE BETTER CHC FOR SHRA/TSRA WILL
BE AT KCMX AND KSAW MID TO LATE AFTERNOON INTO THE EVENING HOURS JUST
AHEAD OF COLD FRONT WORKING THROUGH REGION. MENTIONED ONLY VICINITY
SHRA AT KIWD AS THEY WILL BE FARTHER REMOVED FROM BEST FORCING FOR
SHRA/TSRA ACTIVITY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EDT THU SEP 5 2013
EXPECT SW WINDS UP TO 20-25 KTS ON FRI UNDER SHARPENING PRES
GRADIENT AHEAD OF INCOMING LO PRES TROUGH. FOLLOWING THE PASSAGE OF
A COLD FRONT ON SAT...WINDS WILL VEER TO THE N-NE AND REMAIN UP TO
20 KTS INTO SUN IN ADVANCE OF HI PRES BUILDING TOWARD THE GREAT
LAKES. A RELATIVELY WEAK PRES GRADIENT AND/OR HI OVERWATER STABILITY
WILL THEN DOMINATE ON SUN INTO TUE...RESULTING IN WINDS UNDER 20 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLA/VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
404 AM EDT FRI SEP 6 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL CROSS THE AREA EARLY FRIDAY FOLLOWED
BY CANADIAN HIGH PRESSURE FRIDAY INTO THE WEEKEND. ANOTHER COLD FRONT
WILL DROP ACROSS THE REGION AND DISSIPATE EARLY NEXT WEEK FOLLOWED BY
HIGH PRESSURE INTO MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM FRIDAY...SFC COLD FRONT IS CURRENTLY PUSHING
SOUTHWARD ACROSS THE ILM CWA AT THE MOMENT...AND SHOULD CLEAR THE
ILM CWA AROUND DAYBREAK FRI. THIS VIA LATEST NAM AND HRRR SFC WIND
FIELDS. NOTICEABLY LOWER DEWPOINTS WILL ALSO BE ADVECTING ACROSS
THE FA AS THE POST FRONTAL 1025+ MB SFC HIGH RIDGES ACROSS THE FA
FROM THE NORTH. THE TIGHTENED SFC PG SHOULD KEEP N-NE WINDS AT 5 TO
15 MPH...THE HIER SIDE OF THIS RANGE TO OCCUR ALONG THE COAST. MAX
TEMPS WILL ALSO BE NOTICEABLY DIFFERENT COMPARED TO PREVIOUS
WEEKDAYS...WITH WIDESPREAD 80S AND ONLY A FEW 90 DEGREE READINGS
ACROSS THE FAR SW PORTION OF THE FA. THERE IS HOWEVER...A WEAK S/W
TROF IN THE MID-LEVELS ROTATING THRU THE LONGWAVE UPPER TROF WITH
ITS CURRENT AXIS LYING JUST OFF THE EAST COAST OF THE U.S. THIS
S/W TROF WILL HAVE AVAILABLE MOISTURE TO WORK WITH AS IT PUSHES
SOUTHWARD TO AND ACROSS THE FA LATE THIS AFTERNOON AND TONIGHT. AT
THIS POINT...MODEL TIME HEIGHTS INDICATE POSSIBLE SHALLOW STRATOCU
DECK TO AFFECT THE FA WITH LITTLE VERTICAL EXTENT. IN FACT THE MID
AND UPPER LEVELS REMAIN QUITE DRY. NEVERTHELESS...COULD STILL
SQUEEZE OUT AN ISOLATED SHOWER BUT FOR NOW WILL JUST HIGHLIGHT THE
POSSIBLE CLOUDINESS. WIDESPREAD 80S FOR MAX TEMPS...WITH A FEW 90
DEGREE READING ACROSS THE FAR SW PORTIONS OF THE FA. MIN TEMP
FORECAST COULD BECOME TRICKY DUE TO THE STRATOCU DECK. FOR
NOW...WILL STAY ON THE SLIGHTLY MILDER SIDE OF MODEL MOS GUIDANCE
WITH WIDESPREAD 60S COVERING IT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...SATURDAY BRINGS NW FLOW ALOFT AS TROUGH AXIS
MOVES OFF THE COAST. MEANWHILE SURFACE GRADIENT WILL BE VERY LIGHT
AS HIGH PRESSURE WEAKENS ACROSS THE SOUTHEAST WHILE MAINTAINING A
PRESENCE OFF THE NEW ENGLAND COAST AS WELL AS GULF COAST. EXPECT
PARTLY SUNNY SKY AND SEASONABLE TEMPERATURES. FLOW ALOFT TURNS TO
NORTHERLY ON SUNDAY WHILE SURFACE FLOW REMAINS SIMILARLY WEAK. GOOD
INSOLATION WILL ADD A FEW DEGREES TO HIGHS AND THERE MAY EVEN BE A
BIT LESS SKY COVER DUE TO THE WEAK HEIGHT RISES ASSOC WITH THE
EXITING TROUGHINESS. A COLD FRONT ENTERS THE AREA LATE SUNDAY NIGHT
BUT WILL BE TOO DEPRIVED OF MOISTURE TO BRING ANY MENTIONABLE RAIN
CHANCES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BACKDOOR COLD FRONT SLIPS THROUGH FIRST THING
MONDAY WITH INSUFFICIENT MOISTURE TO BRING ANY REAL CHANCE FOR RAIN.
IN THE UPPER LEVELS THE RIDGING THAT HAD BEEN CONFINED TO THE
NATIONS MIDSECTION DURING THE SHORT TERM WILL NOW BE VERY BROAD AND
WEAK AND COVER REAL ESTATE FROM NM/CO TO THE WEST ATLANTIC. AS SUCH
THERE WILL BE LITTLE COOL ADVECTION IN THE LOW LEVELS AND SEASONABLE
TEMPS ARE EXPECTED FOR MOST OF THE PERIOD. THE HIGH INITIALLY BEHIND
THE FRONT WILL BE CENTERED OVER NEW ENGLAND ON MONDAY. IT WILL
WEAKEN AND PROGRESS EASTWARD THROUGH THE PERIOD BUT EXTEND AN AXIS
INTO THE SOUTHEAST THE ENTIRE TIME PRECLUDING MUCH MOISTURE FLUX
INTO THE CAROLINAS.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...IT IS A TRICKY FOG FORECAST OVERNIGHT AS A COLD FRONT IS
EXPECTED TO MOVE THROUGH THE FORECAST AREA BEFORE 12Z...USHERING IN
SLIGHTLY COOLER AND DRIER AIR. MVFR FOG REMAINS POSSIBLE ACROSS
KLBT/KFLO TERMINALS GIVEN THE DELAY OF THE NNW-NE WINDS AND THE
LOWER SFC DEWPOINTS ACCOMPANYING THEM FROM UPSTREAM. THE BEST FOG
POTENTIAL WILL BE ALONG THE COAST...ESPECIALLY AT KCRE. EXPECT
MVFR/IFR VSBYS AT KCRE AND MVFR VSBYS AT KILM/KMYR UNTIL THE WEAK
NNW-NE SURGE ARRIVES TOWARD DAYBREAK FRI. THE DRIER AIR AND
LOW-LEVEL MIXING WILL HELP VSBYS RAPIDLY IMPROVE...WITH VFR
PREVAILING FOR THE REST OF THE PERIOD. MODEL MOS GUIDANCE HAS
INDICATED THAT KCRE/KMYR MAY HAVE A PROLONGED REDUCED VSBY FROM HAZE
DURING THE DAYTIME MORNING HRS...UNTIL THE POST FRONTAL LOW LEVEL
MIXING FINALLY ARRIVES. THERE IS A SLIGHT CHANCE FOR ISOLATED
CONVECTION...BUT COVERAGE REMAINS VERY LIMITED AND THUS DID NOT
WARRANT MENTIONING IN THE TAFS.
EXTENDED OUTLOOK...MORNING FOG/STRATUS IS POSSIBLE THROUGH THE
EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS SUNDAY NIGHT AND MONDAY.
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM FRIDAY...THE SFC COLD FRONT WILL BE EXITTING SOUTH OF
THE ILM WATERS BY DAYBREAK FRI. THE POST FRONTAL SFC PRESSURE
PATTERN AND TIGHTENED SFC PG WILL YIELD A NE TO ENE WIND AT 10 TO
15 KT WITH GUSTS OVER 20 KT TODAY INTO TONIGHT. COULD APPROACH
SCEC CONDITIONS TONIGHT AS A NE SURGE ACCOMPANYING THE MID-LEVEL
S/W TROF...COULD AFFECT THE ILM WATERS OVERNIGHT. WILL NEED TO
CLOSELY MONITOR THIS. SIGNIFICANT SEAS DOMINATED BY AN EASTERLY
GROUND SWELL AT 9 SECOND PERIODS FOR THE PAST FEW DAYS...WILL
BECOME DOMINATED BY WIND DRIVEN WAVES AT 3 TO 6 SECOND PERIODS.
COULD SEE 2 TO 4 FT SIG SEAS DEVELOP DURING THE OVERNIGHT PERIOD.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WEAKENING HIGH PRESSURE ACROSS THE SOUTHEASTERN
U.S. WHILE MAIN RIDGE MOVES OFF THE NEW ENGLAND COAST. THIS MEANS
AN EASTERLY WIND ACROSS THE FORECAST ZONES AND A GENERAL 2 TO 4 FT
SEAS FCST NORTH AND 2 TO 3 SOUTH. A PREFRONTAL TROUGH DEVELOPS
OVER LAND ON SUNDAY TURING WINDS TO SWRLY WHILE ALSO WEAKENING THE
GRADIENT ENOUGH FOR ABOUT A 5 KT DECREASE IN WIND AND PERHAPS 1 FT
DECREASE IN SEAS. THE COLD FRONT MAY BE ENCROACHING UPON
NORTHERNMOST ZONE BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...BACKDOOR COLD FRONT PUSHES THROUGH EARLY MONDAY.
HIGH PRESSURE DOES NOT PUSH THE BOUNDARY VERY FAR TO THE SOUTH SO NO
REAL NORTHERLY COMPONENT POST FROPA JUST A VEER TO THE NE AND THEN
EAST. ON TUESDAY HIGH PRESSURE WEAKENS BUT MAINTAINS IT PRESENCE
INTO THE SOUTHEASTERN U.S. FROM ITS MAIN CENTER MOVING OFF THE NEW
ENGLAND COAST. WIND REMAINS ONSHORE/EASTERLY AND VERY LIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/BJR
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1011 PM PDT Thu Sep 5 2013
.SYNOPSIS...
The next few days will be stormy with the potential for heavy
rain and thunderstorms. Flash flooding will be a concern tonight,
and Friday. The slow moving low pressure system responsible for
the stormy weather will begin to move out of the region on Sunday.
Monday through Thursday should be warm and will allow the Inland
Northwest to dry out.
&&
.DISCUSSION...
The Severe Thunderstorm Watch has been discontinued Spokane,
Pullman, Moscow, Kellogg, Coeur D`Alene, Moses Lake, Waterville
and Ritzville. RUC analysis shows that the axis of best surface
based (and most unstable) CAPE has shifted north of Interstate 90.
A small threat of severe thunderstorms remains over the far north
Idaho Panhandle and over the northern tier of counties on
Washington. It does appear that the main concern for the remainder
of the night will be excessive rain. Several Flash Flood Warnings
and Flood Advisories are in effect for central Washington
including the burn scar areas around Wenatchee. Storms this
evening have not been able to maintain updrafts long enough to
produce much of a threat for hail or winds. It is possible that
the remaining counties in the severe thunderstorm watch may be
cleared prior to 1 AM, however the jet max advancing toward the
region from Oregon may help storm organization tonight through the
early morning hours. /GKoch
&&
.AVIATION...
00Z TAFS: Very moist and unstable air mass and disturbances rotating
through it have brought significant thunderstorm activity to Eastern
Oregon this afternoon and this will all track to the north and into
Eastern Washington and Northern Idaho this evening and through the
night. In addition to a significant amount of lightning from
thunderstorms they will also bring the potential for very strong and
damaging wind and large hail. The majority if not all of the severe
storm activity should decrease after 8Z Friday. Otherwise VFR
conditions should prevail with exception of localized MVFR ceilings
and visibilities near thunderstorms any any morning stratus/fog that
may form due to the leftover rainfall keeping an abundant source of
moisture at low levels. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 60 68 55 70 54 74 / 80 70 50 40 30 10
Coeur d`Alene 59 68 54 70 54 74 / 90 70 50 50 30 20
Pullman 58 70 50 71 48 75 / 70 70 30 20 20 10
Lewiston 65 78 58 78 59 80 / 60 60 20 10 20 10
Colville 60 72 53 72 50 78 / 90 100 60 70 30 20
Sandpoint 59 66 52 70 50 72 / 90 90 70 70 50 30
Kellogg 56 67 52 70 53 72 / 90 80 60 50 40 30
Moses Lake 62 74 55 74 54 81 / 90 70 30 30 10 10
Wenatchee 62 72 57 73 57 80 / 100 80 50 30 10 10
Omak 63 72 56 73 56 82 / 100 100 70 50 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flash Flood Watch through Friday afternoon for Northern
Panhandle.
WA...Flash Flood Watch through Friday afternoon for East Slopes
Northern Cascades-Northeast Mountains-Okanogan Highlands-
Okanogan Valley-Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
749 AM EDT FRI SEP 6 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL BUILD IN TODAY...AND THEN DRIFT TO THE
SOUTH TONIGHT THROUGH SATURDAY NIGHT. A COLD FRONT WILL PASS
THROUGH ON SUNDAY...FOLLOWED BY HIGH PRESSURE FROM SUNDAY NIGHT
THROUGH WEDNESDAY. ANOTHER COLD FRONT WILL APPROACH ON THURSDAY...
AND PASS THROUGH THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WEAKENS AND SETTLES DIRECTLY OVER THE REGION.
A BROAD WEAK UPPER LEVEL TROUGH MOVES ACROSS THE REGION WHICH
WILL BRING SOME CLOUDS BUT THINKING THAT THE SUBSIDENCE IS THE
GREATER FACTOR HERE WITH A MOSTLY SUNNY SKY PREVAILING. THE CENTER
OF HIGH PRESSURE WILL TREND SOUTH OF THE REGION BY THE LATE
AFTERNOON. A WEAK PRESSURE GRADIENT WILL ENABLE FOR LIGHT
WINDS...AND THE SYNOPTIC FLOW WILL ENABLE FOR A WEAK SEA BREEZE
LATE IN THE AFTERNOON BUT TEMPERATURES ARE FORECAST TO BE ONLY A
FEW DEGREES ABOVE SEA SURFACE TEMPERATURES.
THE AIR MASS WILL BE SLOW TO MODERATE WITH THE WEAK BOUNDARY LAYER
WINDS DESPITE FORECAST MIXING UP TO AROUND 850MB AND WIND DIRECTION
WILL BE VARIABLE. THIS IS CONVEYED THROUGH THE EVOLUTION OF THE
850MB TEMPERATURE FIELD. THE TEMPS WILL STAY MAINLY BETWEEN 5 AND 7
DEGREES C THROUGH THE DAY. MAX TEMPS LOOKED RELATIVELY SIMILAR
BETWEEN MAV AND MET WITH THE CORRESPONDING NUMERICAL MODEL BUFKIT
SOUNDINGS OF GFS AND NAM SHOWING MIXING JUST BELOW AND ABOVE 850MB
RESPECTIVELY. THERE ARE SIMILAR DIFFERENCES BETWEEN THE RUC AND SREF
SOUNDINGS AS WELL. MAX TEMP FORECAST GENERALLY IN THE UPPER 60S
AND LOWER 70S...WHICH WILL BE ABOUT 5-8 DEGREES BELOW AVG.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
FOR TONIGHT...HIGH PRESSURE CONTINUES TO SLOWLY WEAKEN AND MOVE
SOUTH OF THE AREA AS THE UPPER LEVEL TROUGH CONTINUES TO WEAKEN
AND SHIFT WELL EAST OF THE AREA. THIS WILL SET UP A SOUTHWEST WIND
FLOW...WHICH WILL ALLOW FOR SLIGHTLY WARMER LOW TEMPS AND
ESSENTIALLY A MODERATION OF THE AIR MASS. THE 850MB TEMPS ACTUALLY
INCREASE SEVERAL DEGREES DURING THE NIGHT. CLEAR SKIES AND LIGHT
WINDS ESPECIALLY ACROSS THE INTERIOR HOWEVER WILL PROVIDE ANOTHER
GOOD NIGHT OF RADIATIONAL COOLING WHICH WILL OFFSET THE LIGHT
SOUTHWEST FLOW ADVECTING IN WARMER AIR. LOWS WILL BE RELATIVELY
SIMILAR TO THE PREVIOUS NIGHT FOR THE COASTAL AREAS AND URBAN
SECTIONS OF NEW YORK AND NEW JERSEY BUT A FEW DEGREES WARMER
ACROSS THE INTERIOR.
LOWS WERE A BLEND OF MET AND GMOS WITH GREATER WEIGHT FOR MET
GUIDANCE WHICH SHOWS A WIDER RANGE OF TEMPERATURES...WHICH FITS
WELL WITH GOOD RADIATIONAL COOLING.
FOR SATURDAY...HIGH PRESSURE CONTINUES TO WEAKEN AND PUSH SOUTH
OF THE REGION...WITH SOUTHWEST FLOW INCREASING. IN THE UPPER
LEVELS...A NORTHWEST FLOW WILL PREVAIL. TEMPERATURES WILL MAKE A
REBOUND...WITH 850 MB TEMPS INCREASING TO BETWEEN 12 AND 15
DEGREES C AND BOUNDARY LAYER WINDS INCREASE WITH VERTICAL MIXING
UP TO AROUND 900MB. INCREASING CLOUDS WILL START INFILTRATE THE
REGION FROM THE NORTH DURING THE AFTERNOON WELL UPSTREAM OF A
DEEPER SHORTWAVE MOVING INTO ONTARIO. THE HIGHS WERE A BLEND OF
MET AND MAV WITH GREATER WEIGHT TOWARDS THE MET GUIDANCE WHICH
SHOWS GREATER WARMTH ACROSS THE INTERIOR AND COOLER VALUES ALONG
THE COAST. AGAIN...THIS IS SHOWING GREATER RANGE. THIS TIME IT IS
BECAUSE OF THE DOWNSLOPE ACROSS INTERIOR AND MARINE INFLUENCE
ALONG THE COASTAL AREAS. THESE HIGHS WILL BE PRETTY CLOSE TO
NORMAL VALUES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MODELS STILL CLOSELY AGREE ON IDEA OF AN UPPER RIDGE OVER THE PLAINS
STATES AND TROUGH FROM THE MID ATLANTIC INTO EASTERN CANADA TO
START. A VIGOROUS SHORTWAVE WILL DIVE INTO THE BASE OF THE TROUGH ON
SUNDAY...DRIVING A COLD FRONT THROUGH. THIS FRONT WILL BE FOLLOWED
BY A GUSTY NW-N FLOW AS HIGH PRESSURE BUILDS QUICKLY...AND AFTER A
DAY OF NEAR AVG TEMPS ON SUNDAY...A BRIEF COOLER SPELL WILL FOLLOW
FOR SUNDAY NIGHT INTO MON...WITH TEMPS A FEW DEG BELOW AVG.
LOW TEMPS BY MON MORNING COULD APPROACH 40 IN THE COLDEST INTERIOR
VALLEYS AS THE HIGH BUILDS QUICKLY OVERHEAD.
AS THE UPPER TROUGH LIFTS NE WELL INTO NE CANADA...FLOW ALOFT WILL
BECOME MORE ZONAL...ALLOWING THE UPPER HIGH TO BUILD E-WARD TO
THE MID ATLC AND SE COASTS AND A WARM FRONT TO PASS WELL TO OUR
NORTH ON TUE. TEMPS SHOULD SLOWLY WARM DURING MID WEEK...RISING TO
SLIGHTLY ABOVE AVG LEVELS WED AND THU. MULTIPLE SHORTWAVES
EMBEDDED IN THE FLOW SHOULD THEN CARVE OUT A NEW ERN TROUGH LATE
THIS WEEK...BRINGING ANOTHER COLD FRONT TOWARD THE AREA LATE IN
THE WEEK. TIMING OF THE FRONT STILL IN QUESTION...WHILE 00Z
GFS/ECMWF ARE IN AGREEMENT ON FROPA BY EARLY THU MORNING...THE
05/12Z ECMWF IDEA OF A DEEPER UPPER TROUGH AND SLOWER TIMING MAY
STILL BE PLAUSIBLE AND HAVE DELAYED FRONTAL APPROACH UNTIL DAYTIME
THU...AND FROPA UNTIL THU NIGHT...WITH SHOWERS AND POSSIBLE TSTMS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS TODAY.
VFR THRU THE TAF PERIOD.
LIGHT NORTH TO NORTH-NORTHEAST WINDS WILL VEER TO THE NORTHEAST THIS
MORNING. WINDS THEN WEAKEN AND SHIFT TO THE SOUTH THIS AFTERNOON.
WINDS SPEEDS WILL REMAIN 10KT OR LESS...WITH MOST TERMINALS BECOMING
LIGHT AND VARIABLE.
A WEAK SEA BREEZE IS POSSIBLE ALONG THE IMMEDIATE SOUTH COASTAL
AIRPORTS. AWAY FROM THE COAST...EXPECT LIGHT AND VARIABLE WINDS.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WIND SHIFT
EXPECTED DURING THE AFTERNOON. TIMING MAY BE OFF BY AN HOUR OR TWO.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WIND SHIFT
EXPECTED DURING THE AFTERNOON. TIMING MAY BE OFF BY AN HOUR OR TWO.
KEWR FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WIND SHIFT
EXPECTED DURING THE AFTERNOON. TIMING MAY BE OFF BY AN HOUR OR TWO.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WINDS BECOME
LIGHT AND VARIABLE DURING THE AFTERNOON. TIMING MAY BE OFF BY AN
HOUR OR TWO.
KHPN FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WINDS BECOME
LIGHT AND VARIABLE DURING THE AFTERNOON. TIMING MAY BE OFF BY AN
HOUR OR TWO.
KISP FCSTER COMMENTS: HIGH CONFIDENCE VFR FORECAST. WINDS BECOME
LIGHT AND VARIABLE DURING THE AFTERNOON. TIMING MAY BE OFF BY AN
HOUR OR TWO.
OUTLOOK FOR 12Z SAT THROUGH MON...
.SATURDAY-SATURDAY NIGHT...VFR.
.SUNDAY...ISOLATED SHOWERS WITH BRIEF MVFR CONDITIONS POSSIBLE.
.SUNDAY NIGHT-TUESDAY...VFR.
&&
.MARINE...
SUB SCA CONDITIONS EXPECTED THROUGH SATURDAY. COLD AIR ADVECTION
OVER THE WARMER WATERS WILL ALLOW FOR GUSTS UP TO 20 KT INTO THIS
MORNING. WIND GUSTS WILL THEN SUBSIDE LATE THIS MORNING AND
AFTERNOON AS A HIGH PRESSURE CENTER TO THE WEST MOVES CLOSER TO
THE AREA. THE NORTHERLY WIND FLOW WILL WEAKEN AND BECOME MORE
VARIABLE IN DIRECTION...BEFORE TURNING MORE SOUTHWESTERLY TONIGHT.
WINDS WILL PICK UP MORE ON SATURDAY TO AROUND 10-15 KT IN THE
AFTERNOON. SEAS WILL STAY MAINLY BETWEEN 2 TO 3 FT ON THE OCEAN
THROUGH SATURDAY.
SW FLOW AHEAD OF A COLD FRONT ON SUNDAY COULD BUILD THE OCEAN SEAS
OFF EASTERN LONG ISLAND TO 5 FT. POST-FRONTAL NW-N FLOW AS STRONG
HIGH PRESSURE BUILDS IN QUICKLY SHOULD GUST TO 25-30 ON THE OCEAN
AND THE ERN SOUND/BAYS SUNDAY NIGHT AND PERHAPS INTO PART OF MON
MORNING...WITH MAX OCEAN SEAS 6 FT DURING THAT TIME.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE MIDDLE OF
NEXT WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD...THE NEW
YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 HAS BEEN
TEMPORARILY TAKEN OUT OF SERVICE WHILE A SOLUTION IS BEING
FORMULATED.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS RADIO PUBLIC WARNING
SYSTEM DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.CLIMATE..
THE LOW TEMPERATURE AT CENTRAL PARK SO FAR THIS MORNING WAS
57...THE COLDEST TEMPERATURE AT THE PARK SINCE JUNE 14TH WHEN THE
LOW WAS 53.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS/NEAR TERM/MARINE/HYDROLOGY...JM/GOODMAN
SHORT TERM...JM
LONG TERM/EQUIPMENT/CLIMATE...GOODMAN
AVIATION...BC
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
948 AM EDT FRI SEP 6 2013
.DISCUSSION...
...SOME STRONG STORMS EXPECTED ACROSS THE INTERIOR THIS AFTERNOON...
.UPDATE...UPR LVL TROUGH EXTENDS INTO FL AND THE ERN GULF WITH
BACKDOOR SFC FRONT EXPECTED TO MOVE INTO NE FL LATER TODAY. TAMPA
SOUNDING DATA AND GPS PWAT DATA ACROSS CENTRAL FL INDICATE ELEVATED
MOISTURE LVLS WITH PWATS 1.8-2.0 INCHES AND H5 TEMPS AROUND -8 DEG
C. FULL SUN MANY AREAS THIS MORNING SHOULD LEAD TO PLENTY OF CAPE
LATER TODAY FOR SCATTERED SHOWER/TSTM DEVELOPMENT. 4.5KM WRF FOR
SPC/LOCAL WRF RUNS AND HRRR INDICATED HIGHER COVERAGE OF SHOWERS AND
STORMS ACROSS INTERIOR SECTIONS LATER THIS AFTERNOON AND WILL BUMP
UP POPS TO 50 PCT FOR LAKE COUNTY AND THE KISSIMMEE RIVER BASIN
ACROSS WESTERN OSCEOLA AND WESTERN OKEECHOBEE COUNTIES. WILL KEEP
40 PCT FOR THE REMAINDER OF THE INTERIOR AND 20 PCT ALONG THE
IMMEDIATE COAST WHERE E COAST BREEZE WILL MOVE INLAND. HIGHS NEAR 90
ALONG THE COAST AND THE LOWER TO MID 90S INTERIOR. THERE COULD BE
SOME STRONGER STORMS BY LATE AFTERNOON OVER THE INTERIOR WITH
FREQUENT CLOUD TO GROUND LIGHTNINGS...DOWNBURST WINDS TO 50 MPH AND
LOCALLY HEAVY RAINFALL AMOUNTS OF 2-3 INCHES.
&&
.AVIATION...EXPECT INTERIOR TERMINALS TO HAVE HIGHEST TSRA CHCS FROM
KSFB-KMCO VCNTY WESTWARD LATER THIS AFTERNOON. WILL CONSIDER TEMPO
TSRA FOR SOME INTERIOR SITES BTWN 19Z-23Z.
&&
.MARINE...WIND CALM AT BUOY 41009 SINCE 6 AM WITH 1-2 FT SEAS AND AN
8 SECOND PERIOD. LITTLE CHANGE FOR AFTERNOON FCST.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
VOLKMER/SEDLOCK
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1136 AM EDT FRI SEP 6 2013
.UPDATE...
NO CHANGES PLANNED TO THE FORECAST AS ITS ON TRACK. SOMEWHAT
QUESTIONABLE ABOUT THE SLIGHT CHANCE POPS IN THE MOUNTAINS THIS
AFTERNOON AND HRRR ISNT SHOWING ANYTHING DEVELOPING THERE. WITH
POTENTIAL FOR OROGRAPHIC LIFT...WILL LEAVE THE SLIGHT CHANCE IN
THERE FOR NOW AND WATCH TRENDS AS WE MOVE INTO THE AFTERNOON.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 401 AM EDT FRI SEP 6 2013/
RELATIVELY DRY WX PATTERN TO CONTINUE TODAY AND SATURDAY AS LARGE
UPPER RIDGE CENTERED OVER THE CENTRAL HIGH PLAINS BUILDS EAST...
VERY WEAK NW FLOW PERSISTS OVER THE REGION AND GENERAL LACK OF ANY
SHORT WAVES/FRONTS UPSTREAM IN WESTERLIES OVER GREAT LAKES STATES.
WEAK STATIONARY FRONT OVER SOUTH GA STILL HAVING TROUBLE DECIDING
WHAT TO DO. LOW LEVEL MOISTURE IS HIGHER THAN FCST THIS MORNING
.BUT ABSOLUTELY NO SIGN OF PRECIP IN NEARLY ALL MODEL GUIDANCE
FOR TODAY. ONLY THE HIRES WINDOW NMM SHOWS ISOLATED TSRA. HAVE
LOWERED/ DROPPED POPS BUT KEPT THEM AROUND 20PCT IN FAR SOUTHERN
ZONES AND NE GA MOUNTAINS. AS WITH LAST FEW DAYS...ANY TSRA WILL
NOT BE TOO STRONG AND WELL BELOW SEVERE LEVELS. SBCAPE PROGGED
500-1000 J/KG OVER FAR SRN ZONES. NAM AGAIN HAS A BAD CASE OF THE
CRAZIES WITH LACK OF VERTICAL MIXING AND TOO MUCH LOW LEVEL
MOISTURE AND CAPE IN THE AFTERNOON.
IF ONE THINKS TODAYS FCST IS DRY...WAIT TIL SATURDAY WITH NO POPS
FCST. AIRMASS CONTINUES TO DRY. FORTUNATELY TEMPS TO REMAIN JUST
ABOVE NORMAL...WHICH IS NO TOO SHABBY THIS TIME OF YEAR.
SNELSON
LONG TERM /SUNDAY THROUGH THURSDAY/...
/ISSUED 401 AM EDT FRI SEP 6 2013/
UPPER TROUGH MOVING OFF THE NORTHEAST COAST AT THE START OF THE
PERIOD WITH NORTHWEST FLOW CONTINUING ALOFT FOR THE CWA. THIS
SHOULD PUSH ANOTHER WEAK BACK DOOR FRONT INTO THE AREA LATE SUNDAY
EARLY MONDAY. HAVE KEPT LOW POPS IN FOR THIS TIME FRAME BUT
FAVORED THE NORTHERN ZONES. UPPER RIDGE BUILDS EASTWARD INTO THE
FORECAST AREA THROUGH MID WEEK. AFTERNOON HEATING SHOULD BE ABLE
TO TRIGGER A FEW THUNDERSTORMS EACH DAY. BY THE END OF THE WEEK
ANOTHER UPPER TROUGH MOVING ACROSS NEW ENGLAND SHOULD PUSH ANOTHER
BACK DOOR FRONT INTO THE SOUTHERN APPALACHIANS. AN INCREASE IN
DEEPER MOISTURE SHOULD GIVE CHANCE POPS TO THE CWA...FAVORING THE
NORTHERN ZONES. WITH INCREASED THICKNESS ALOFT AFTERNOON MAX
TEMPERATURES SHOULD GENERALLY RANGE MID 80S TO LOW 90S.
41
AVIATION...
12Z UPDATE...
/ISSUED 733 AM EDT FRI SEP 6 2013/
STILL NOT EXPECTING ANY PRECIP OR IMPACTS TODAY. SFC WINDS HAVE
SWITCHED TO NORTHEAST AS EXPECTED. PATCHY MVFR FOG WILL BE LIFTING
BEFORE 14Z BUT WILL LIKELY REDEVELOP AFTER 06Z TONIGHT.
//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 66 88 69 / 10 5 10 5
ATLANTA 88 69 88 72 / 10 5 10 10
BLAIRSVILLE 83 61 83 65 / 20 10 10 5
CARTERSVILLE 89 65 88 68 / 10 5 10 5
COLUMBUS 92 70 90 72 / 10 5 10 5
GAINESVILLE 85 66 86 70 / 10 5 10 5
MACON 91 67 90 69 / 10 5 10 5
ROME 90 65 89 68 / 5 5 10 5
PEACHTREE CITY 89 65 88 67 / 10 5 10 5
VIDALIA 90 70 89 72 / 20 10 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...11
LONG TERM....01
AVIATION...11
AREA FORECAST DISCUSSION
NWS POCATELLO ID
920 AM MDT FRI SEP 6 2013
.UPDATED DISCUSSION...MORNING WV SAT LOOP SHOWING A LITTLE BACKING
OF THE MONSOON PLUME. NAM AND HRRR MODELS ALSO SUGGESTING TSTMS
LATER THIS AFTN AND EARLY EVE MORE TO THE WEST THAN PREVIOUSLY
INDICATED. HAVE PUSHED THE HIGHER POPS FROM THE EASTERN HIGHLANDS
BACK WESTWARD TO THE ADJACENT SNAKE RIVER PLAIN AS A RESULT. STRONG
UPPER LEVEL FLOW SHOULD RESULT IN FASTER CELL MOVEMENT...THUS A
LOWER CHANCE FOR HEAVY RAINFALL. HEDGES
.SHORT TERM...TODAY THROUGH SUNDAY
UPPER LOW CONTINUES TO PUSH NORTHEAST TODAY INTO WASHINGTON STATE
WITH SOUTHERLY FLOW ALOFT CONTINUING TO PUSH MOISTURE INTO THE
REGION. A COLD FRONT WILL MOVE THROUGH EASTERN IDAHO ALSO AND
EXPECT SLIGHTLY COOLER TEMPERATURES TODAY. DO EXPECT ISOLATED TO
SCATTERED THUNDERSTORMS ONCE AGAIN WITH THE BEST CHANCE IN THE
EASTERN HIGHLANDS TODAY. UPPER LOW MAKES SLOW PROGRESSION EAST
THROUGH THE WEEKEND AND EXPECT AT LEAST SOME ISOLATED THUNDERSTORM
ACTIVITY TO CONTINUE THROUGH THE WEEKEND. EXPECT SOME CONTINUED
COOLING THROUGH SUNDAY BUT TEMPERATURES STILL REMAINING SLIGHTLY
ABOVE NORMAL.
GK
.LONG TERM...MONDAY THROUGH FRIDAY.
UPPER FLOW TURNS NORTHWESTERLY MONDAY AFTER UPPER TROF FINALLY
PUSHES EAST. EXPECT DRY CONDITIONS MONDAY AND TUESDAY. MODELS
RETURN TO SOUTHERLY FLOW LATE NEXT WEEK AND EUROPEAN HAS SOME
PRECIPITATION AS EARLY AS WEDNESDAY BUT HELD OFF ON GRIDS UNTIL
THURSDAY RETURNING TO CONVECTIVE ACTIVITY. MONDAY WILL BE THE
COOLEST DAY OF THE LONG TERM WITH NEAR NORMAL TEMPERATURES. EXPECT
ABOVE NORMAL CONDITIONS RETURNING TUESDAY.
GK
&&
.AVIATION...ALTHOUGH WE SHOULD SEE A BREAK IN THE NOCTURNAL
THUNDERSTORM ACTIVITY AT KSUN THIS MORNING...THE TERMINAL WILL
LIKELY SEE RENEWED ACTIVITY THIS AFTERNOON AS A LOW PRESSURE SYSTEM
LIFTS SLOWLY NORTH INTO WASHINGTON. KPIH AND KIDA MAY ALSO SEE VCTS
THIS AFTERNOON AS CONVECTION BUILDS ACROSS THE SE HIGHLANDS
ASSOCIATED WITH A BAND OF SUB-TROPICAL MOISTURE STILL ARCING NORTH
INTO THE REGION. ALL IN ALL...VFR CONDITIONS SHOULD PREVAIL. HUSTON
&&
.FIRE WEATHER...EARLY MORNING SATELLITE IMAGERY CONTINUED TO SHOW A
RIDGE OF HIGH PRESSURE ANCHORED OVER COLORADO AS A LOW PRESSURE
SYSTEM WAS LIFTING GRADUALLY NE ACROSS OREGON. THUNDERSTORM ACTIVITY
CONTINUED TO FIRE ACROSS THE CNTRL MOUNTAINS IN CLOSER PROXIMITY TO
THE CENTER OF THE LOW AND UPPER JET DYNAMICS. AS THE LOW DRIFTS
SLOWLY NORTH INTO WASHINGTON TODAY...THUNDERSTORMS WILL CONTINUE TO
DEVELOP ACROSS MAINLY THE CNTRL MOUNTAINS AND SE HIGHLANDS WHERE THE
BEST INSTABILITY...MOISTURE...AND DYNAMICAL FORCING RESIDE. THE LOW
EVENTUALLY LIFTS INTO SRN BRITISH COLUMBIA SATURDAY AS A
DRIER...MORE STABLE SW FLOW OVERSPREADS THE CNTRL MOUNTAINS AND
SUB-TROPICAL MOISTURE CONTINUES TO ARC NORTH ACROSS THE GREAT BASIN
INTO THE ERN HIGHLANDS SUPPORTING ONGOING THUNDERSTORM ACTIVITY
ALONG THE UTAH/WYOMING BORDER REGIONS. BY SUNDAY THE LOW DRIFTS
FURTHER EAST INTO ALBERTA AS THE FLOW ALOFT BECOMES MORE WESTERLY.
THE BEST CHANCE FOR SHOWERS IS EXPECTED ALONG THE MONTANA BORDER
CLOSER TO THE CORE OF THE LOW AND NEAR THE WYOMING BORDER WHERE
RESIDUAL SUB-TROPICAL MOISTURE LINGERS. BY MONDAY A DRY AND STABLE
NW FLOW TAKES HOLD WHILE AFTERNOON HIGHS BOTTOM OUT NEAR THEIR
NORMAL CLIMATOLOGICAL HIGHS FOR THIS TIME OF YEAR. A HIGH PRESSURE
RIDGE BUILDS INTO THE AREA BY MID-WEEK BRINGING WARMER TEMPERATURES
WHILE THE MODELS THROW A WILD-CARD INTO THE MIX AS A SUB-TROPICAL
STORM IS EVIDENT LIFTING NORTH ALONG THE SRN CALIFORNIA COAST. THIS
APPROACHING STORM MAY BRING A CHANCE OF AFTERNOON THUNDERSTORMS BACK
TO THE REGION AS EARLY AS THURSDAY. HUSTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
735 AM EDT FRI SEP 6 2013
.SYNOPSIS...
HIGH PRESSURE IS EXPECTED ACROSS THE AREA INTO THE WEEKEND. ANOTHER
COLD FRONT WILL DROP ACROSS THE REGION AND DISSIPATE EARLY NEXT
WEEK...FOLLOWED BY HIGH PRESSURE INTO MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...VIA LATEST OBS...AND NAM AND HRRR SFC WIND
FIELDS...N TO NE WINDS HAVE ENGULFED THE ILM CWA AND ADJACENT
COASTAL WATERS. NOTICEABLY LOWER DEWPOINTS...WIDESPREAD 60S...
WILL CONTINUE TO ADVECT ACROSS THE FA AS THE POST FRONTAL 1025+
MB SFC HIGH RIDGES ACROSS THE FA FROM THE NORTH. THE TIGHTENED SFC
PG SHOULD KEEP N-NE WINDS AT 5 TO 15 MPH...THE HIER SIDE OF THIS
RANGE TO OCCUR ALONG THE IMMEDIATE COAST. MAX TEMPS WILL ALSO BE
NOTICEABLY DIFFERENT COMPARED TO PREVIOUS WEEKDAYS...WITH
WIDESPREAD 80S AND ONLY A FEW 90 DEGREE READINGS ACROSS THE FAR SW
PORTION OF THE FA. THERE IS HOWEVER...A WEAK S/W TROF IN THE MID-
LEVELS ROTATING THRU THE LONGWAVE UPPER TROF...WITH ITS CURRENT
AXIS LYING JUST OFF THE EAST COAST OF THE U.S. THIS S/W TROF WILL
HAVE AVAILABLE MOISTURE TO WORK WITH AS IT PUSHES SOUTHWARD TO AND
ACROSS THE FA LATE THIS AFTERNOON AND TONIGHT. AT THIS
POINT...MODEL TIME HEIGHTS INDICATE POSSIBLE SHALLOW CU/STRATOCU
DECK TO AFFECT THE FA WITH LITTLE VERTICAL EXTENT. IN FACT THE
MID AND UPPER LEVELS REMAIN QUITE DRY. NEVERTHELESS...COULD STILL
SQUEEZE OUT AN ISOLATED SHOWER BUT FOR NOW WILL JUST HIGHLIGHT THE
POSSIBLE CLOUDINESS. MIN TEMP FORECAST COULD BECOME TRICKY DUE TO
THE STRATOCU DECK. FOR NOW...WILL STAY ON THE SLIGHTLY MILDER SIDE
OF MODEL MOS GUIDANCE WITH WIDESPREAD MID 60S...UPPER 60S AT THE
COAST...COVERING IT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...SATURDAY BRINGS NW FLOW ALOFT AS TROUGH AXIS
MOVES OFF THE COAST. MEANWHILE SURFACE GRADIENT WILL BE VERY LIGHT
AS HIGH PRESSURE WEAKENS ACROSS THE SOUTHEAST WHILE MAINTAINING A
PRESENCE OFF THE NEW ENGLAND COAST AS WELL AS GULF COAST. EXPECT
PARTLY SUNNY SKY AND SEASONABLE TEMPERATURES. FLOW ALOFT TURNS TO
NORTHERLY ON SUNDAY WHILE SURFACE FLOW REMAINS SIMILARLY WEAK. GOOD
INSOLATION WILL ADD A FEW DEGREES TO HIGHS AND THERE MAY EVEN BE A
BIT LESS SKY COVER DUE TO THE WEAK HEIGHT RISES ASSOC WITH THE
EXITING TROUGHINESS. A COLD FRONT ENTERS THE AREA LATE SUNDAY NIGHT
BUT WILL BE TOO DEPRIVED OF MOISTURE TO BRING ANY MENTIONABLE RAIN
CHANCES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BACKDOOR COLD FRONT SLIPS THROUGH FIRST THING
MONDAY WITH INSUFFICIENT MOISTURE TO BRING ANY REAL CHANCE FOR RAIN.
IN THE UPPER LEVELS THE RIDGING THAT HAD BEEN CONFINED TO THE
NATIONS MIDSECTION DURING THE SHORT TERM WILL NOW BE VERY BROAD AND
WEAK AND COVER REAL ESTATE FROM NM/CO TO THE WEST ATLANTIC. AS SUCH
THERE WILL BE LITTLE COOL ADVECTION IN THE LOW LEVELS AND SEASONABLE
TEMPS ARE EXPECTED FOR MOST OF THE PERIOD. THE HIGH INITIALLY BEHIND
THE FRONT WILL BE CENTERED OVER NEW ENGLAND ON MONDAY. IT WILL
WEAKEN AND PROGRESS EASTWARD THROUGH THE PERIOD BUT EXTEND AN AXIS
INTO THE SOUTHEAST THE ENTIRE TIME PRECLUDING MUCH MOISTURE FLUX
INTO THE CAROLINAS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...TERMINALS ARE VFR THIS MORNING AND VFR IS EXPECTED
THROUGH MIDNIGHT. SCATTERED 200 FOOT STRATUS AT KCRE IS EXPECTED
TO MIX OUT QUICKLY OVER THE NEXT HOUR OR TWO. AN UPPER IMPULSE
WILL PASS LATER TODAY WITH SHOWERS AND POSSIBLY A THUNDERSTORM
MOVING SOUTH TOWARDS KILM. WILL INDICATE VCSH LATER THIS AFTERNOON
ONLY AT KILM WHERE A RESULTANT BOUNDARY WILL INTERACT WITH THE
IMPULSE AT MAX HEATING. SINCE ANY THUNDERSTORM IS EXPECTED TO BE
ISOLATED THERE IS LOW CONFIDENCE OF VCTS AT KILM. ACTIVITY WILL
MOVE OFFSHORE 01-02Z.
MODELS SOUNDINGS ARE INDICATING SUFFICIENT LOW-LEVEL MOISTURE TO
PRODUCE MVFR/IFR CONDITIONS AFTER 06Z. THE BEST CHANCE OF MVFR WILL
BE AT THE KILM/KCRE/KMYR WITH THE BEST CHANCE OF IFR AT KFLO AND TO
A LESSER EXTENT KLBT.
EXTENDED OUTLOOK...MORNING FOG/STRATUS IS POSSIBLE THROUGH THE
EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS SUNDAY NIGHT AND MONDAY.
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...THE SFC COLD FRONT HAS EXITED SOUTH OF THE
ILM WATERS BY DAYBREAK FRI. THE POST FRONTAL SFC PRESSURE PATTERN
AND TIGHTENED SFC PG WILL YIELD A NE TO ENE WIND AT 10 TO 15 KT
WITH FEW GUSTS OVER 20 KT TODAY INTO TONIGHT. COULD APPROACH SCEC
CONDITIONS TONIGHT AS A NE SURGE ACCOMPANYING THE MID-LEVEL S/W
TROF...COULD AFFECT THE ILM WATERS OVERNIGHT. WILL NEED TO CLOSELY
MONITOR THIS. SIGNIFICANT SEAS DOMINATED BY AN EASTERLY GROUND
SWELL AT 9 SECOND PERIODS FOR THE PAST FEW DAYS...WILL BECOME
DOMINATED BY WIND DRIVEN WAVES AT 3 TO 6 SECOND PERIODS. COULD SEE
2 TO 4 FT SIG SEAS DEVELOP BY OR DURING THE OVERNIGHT PERIOD.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WEAKENING HIGH PRESSURE ACROSS THE SOUTHEASTERN
U.S. WHILE MAIN RIDGE MOVES OFF THE NEW ENGLAND COAST. THIS MEANS
AN EASTERLY WIND ACROSS THE FORECAST ZONES AND A GENERAL 2 TO 4 FT
SEAS FCST NORTH AND 2 TO 3 SOUTH. A PREFRONTAL TROUGH DEVELOPS
OVER LAND ON SUNDAY TURING WINDS TO SWRLY WHILE ALSO WEAKENING THE
GRADIENT ENOUGH FOR ABOUT A 5 KT DECREASE IN WIND AND PERHAPS 1 FT
DECREASE IN SEAS. THE COLD FRONT MAY BE ENCROACHING UPON
NORTHERNMOST ZONE BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...BACKDOOR COLD FRONT PUSHES THROUGH EARLY MONDAY.
HIGH PRESSURE DOES NOT PUSH THE BOUNDARY VERY FAR TO THE SOUTH SO NO
REAL NORTHERLY COMPONENT POST FROPA JUST A VEER TO THE NE AND THEN
EAST. ON TUESDAY HIGH PRESSURE WEAKENS BUT MAINTAINS IT PRESENCE
INTO THE SOUTHEASTERN U.S. FROM ITS MAIN CENTER MOVING OFF THE NEW
ENGLAND COAST. WIND REMAINS ONSHORE/EASTERLY AND VERY LIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB/MRR
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
704 AM EDT FRI SEP 6 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL CROSS THE AREA EARLY FRIDAY FOLLOWED
BY CANADIAN HIGH PRESSURE FRIDAY INTO THE WEEKEND. ANOTHER COLD FRONT
WILL DROP ACROSS THE REGION AND DISSIPATE EARLY NEXT WEEK FOLLOWED BY
HIGH PRESSURE INTO MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...VIA LATEST OBS...AND NAM AND HRRR SFC WIND
FIELDS...N TO NE WINDS HAVE ENGULFED THE ILM CWA AND ADJACENT
COASTAL WATERS. NOTICEABLY LOWER DEWPOINTS...WIDESPREAD 60S...
WILL CONTINUE TO ADVECT ACROSS THE FA AS THE POST FRONTAL 1025+
MB SFC HIGH RIDGES ACROSS THE FA FROM THE NORTH. THE TIGHTENED SFC
PG SHOULD KEEP N-NE WINDS AT 5 TO 15 MPH...THE HIER SIDE OF THIS
RANGE TO OCCUR ALONG THE IMMEDIATE COAST. MAX TEMPS WILL ALSO BE
NOTICEABLY DIFFERENT COMPARED TO PREVIOUS WEEKDAYS...WITH
WIDESPREAD 80S AND ONLY A FEW 90 DEGREE READINGS ACROSS THE FAR SW
PORTION OF THE FA. THERE IS HOWEVER...A WEAK S/W TROF IN THE MID-
LEVELS ROTATING THRU THE LONGWAVE UPPER TROF...WITH ITS CURRENT
AXIS LYING JUST OFF THE EAST COAST OF THE U.S. THIS S/W TROF WILL
HAVE AVAILABLE MOISTURE TO WORK WITH AS IT PUSHES SOUTHWARD TO AND
ACROSS THE FA LATE THIS AFTERNOON AND TONIGHT. AT THIS
POINT...MODEL TIME HEIGHTS INDICATE POSSIBLE SHALLOW CU/STRATOCU
DECK TO AFFECT THE FA WITH LITTLE VERTICAL EXTENT. IN FACT THE
MID AND UPPER LEVELS REMAIN QUITE DRY. NEVERTHELESS...COULD STILL
SQUEEZE OUT AN ISOLATED SHOWER BUT FOR NOW WILL JUST HIGHLIGHT THE
POSSIBLE CLOUDINESS. MIN TEMP FORECAST COULD BECOME TRICKY DUE TO
THE STRATOCU DECK. FOR NOW...WILL STAY ON THE SLIGHTLY MILDER SIDE
OF MODEL MOS GUIDANCE WITH WIDESPREAD MID 60S...UPPER 60S AT THE
COAST...COVERING IT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...SATURDAY BRINGS NW FLOW ALOFT AS TROUGH AXIS
MOVES OFF THE COAST. MEANWHILE SURFACE GRADIENT WILL BE VERY LIGHT
AS HIGH PRESSURE WEAKENS ACROSS THE SOUTHEAST WHILE MAINTAINING A
PRESENCE OFF THE NEW ENGLAND COAST AS WELL AS GULF COAST. EXPECT
PARTLY SUNNY SKY AND SEASONABLE TEMPERATURES. FLOW ALOFT TURNS TO
NORTHERLY ON SUNDAY WHILE SURFACE FLOW REMAINS SIMILARLY WEAK. GOOD
INSOLATION WILL ADD A FEW DEGREES TO HIGHS AND THERE MAY EVEN BE A
BIT LESS SKY COVER DUE TO THE WEAK HEIGHT RISES ASSOC WITH THE
EXITING TROUGHINESS. A COLD FRONT ENTERS THE AREA LATE SUNDAY NIGHT
BUT WILL BE TOO DEPRIVED OF MOISTURE TO BRING ANY MENTIONABLE RAIN
CHANCES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...BACKDOOR COLD FRONT SLIPS THROUGH FIRST THING
MONDAY WITH INSUFFICIENT MOISTURE TO BRING ANY REAL CHANCE FOR RAIN.
IN THE UPPER LEVELS THE RIDGING THAT HAD BEEN CONFINED TO THE
NATIONS MIDSECTION DURING THE SHORT TERM WILL NOW BE VERY BROAD AND
WEAK AND COVER REAL ESTATE FROM NM/CO TO THE WEST ATLANTIC. AS SUCH
THERE WILL BE LITTLE COOL ADVECTION IN THE LOW LEVELS AND SEASONABLE
TEMPS ARE EXPECTED FOR MOST OF THE PERIOD. THE HIGH INITIALLY BEHIND
THE FRONT WILL BE CENTERED OVER NEW ENGLAND ON MONDAY. IT WILL
WEAKEN AND PROGRESS EASTWARD THROUGH THE PERIOD BUT EXTEND AN AXIS
INTO THE SOUTHEAST THE ENTIRE TIME PRECLUDING MUCH MOISTURE FLUX
INTO THE CAROLINAS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...IT IS A TRICKY FOG FORECAST OVERNIGHT AS A COLD FRONT IS
EXPECTED TO MOVE THROUGH THE FORECAST AREA BEFORE 12Z...USHERING IN
SLIGHTLY COOLER AND DRIER AIR. MVFR FOG REMAINS POSSIBLE ACROSS
KLBT/KFLO TERMINALS GIVEN THE DELAY OF THE NNW-NE WINDS AND THE
LOWER SFC DEWPOINTS ACCOMPANYING THEM FROM UPSTREAM. THE BEST FOG
POTENTIAL WILL BE ALONG THE COAST...ESPECIALLY AT KCRE. EXPECT
MVFR/IFR VSBYS AT KCRE AND MVFR VSBYS AT KILM/KMYR UNTIL THE WEAK
NNW-NE SURGE ARRIVES TOWARD DAYBREAK FRI. THE DRIER AIR AND
LOW-LEVEL MIXING WILL HELP VSBYS RAPIDLY IMPROVE...WITH VFR
PREVAILING FOR THE REST OF THE PERIOD. MODEL MOS GUIDANCE HAS
INDICATED THAT KCRE/KMYR MAY HAVE A PROLONGED REDUCED VSBY FROM HAZE
DURING THE DAYTIME MORNING HRS...UNTIL THE POST FRONTAL LOW LEVEL
MIXING FINALLY ARRIVES. THERE IS A SLIGHT CHANCE FOR ISOLATED
CONVECTION...BUT COVERAGE REMAINS VERY LIMITED AND THUS DID NOT
WARRANT MENTIONING IN THE TAFS.
EXTENDED OUTLOOK...MORNING FOG/STRATUS IS POSSIBLE THROUGH THE
EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS SUNDAY NIGHT AND MONDAY.
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...THE SFC COLD FRONT HAS EXITED SOUTH OF THE
ILM WATERS BY DAYBREAK FRI. THE POST FRONTAL SFC PRESSURE PATTERN
AND TIGHTENED SFC PG WILL YIELD A NE TO ENE WIND AT 10 TO 15 KT
WITH FEW GUSTS OVER 20 KT TODAY INTO TONIGHT. COULD APPROACH SCEC
CONDITIONS TONIGHT AS A NE SURGE ACCOMPANYING THE MID-LEVEL S/W
TROF...COULD AFFECT THE ILM WATERS OVERNIGHT. WILL NEED TO CLOSELY
MONITOR THIS. SIGNIFICANT SEAS DOMINATED BY AN EASTERLY GROUND
SWELL AT 9 SECOND PERIODS FOR THE PAST FEW DAYS...WILL BECOME
DOMINATED BY WIND DRIVEN WAVES AT 3 TO 6 SECOND PERIODS. COULD SEE
2 TO 4 FT SIG SEAS DEVELOP BY OR DURING THE OVERNIGHT PERIOD.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WEAKENING HIGH PRESSURE ACROSS THE SOUTHEASTERN
U.S. WHILE MAIN RIDGE MOVES OFF THE NEW ENGLAND COAST. THIS MEANS
AN EASTERLY WIND ACROSS THE FORECAST ZONES AND A GENERAL 2 TO 4 FT
SEAS FCST NORTH AND 2 TO 3 SOUTH. A PREFRONTAL TROUGH DEVELOPS
OVER LAND ON SUNDAY TURING WINDS TO SWRLY WHILE ALSO WEAKENING THE
GRADIENT ENOUGH FOR ABOUT A 5 KT DECREASE IN WIND AND PERHAPS 1 FT
DECREASE IN SEAS. THE COLD FRONT MAY BE ENCROACHING UPON
NORTHERNMOST ZONE BY THE END OF THE PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...BACKDOOR COLD FRONT PUSHES THROUGH EARLY MONDAY.
HIGH PRESSURE DOES NOT PUSH THE BOUNDARY VERY FAR TO THE SOUTH SO NO
REAL NORTHERLY COMPONENT POST FROPA JUST A VEER TO THE NE AND THEN
EAST. ON TUESDAY HIGH PRESSURE WEAKENS BUT MAINTAINS IT PRESENCE
INTO THE SOUTHEASTERN U.S. FROM ITS MAIN CENTER MOVING OFF THE NEW
ENGLAND COAST. WIND REMAINS ONSHORE/EASTERLY AND VERY LIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/BJR
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
357 PM MDT FRI SEP 6 2013
.SHORT TERM...PRESENT FORECAST GRIDS NEED LITTLE WORK. ONGOING
CONVECTION SHOULD CONFINE ITSELF MOSTLY TO THE FOOTHILLS THIS
EVENING ALTHOUGH SEVERAL RECENT HRRR RUNS WANT TO BRING A BIT OF
IT SOUTHEAST ACROSS THE NORTHERN/CENTRAL PORTIONS OF THE URBAN
CORRIDOR TOWARDS 00Z.
SATURDAY SHOULD BE CLOSE TO A CARBON COPY OF TODAY AS THE UPPER
LEVEL ANTICYCLONE KEEPS ITS FURNACE-LIKE GRIP ON THE REGION.
WELL ABOVE NORMAL TEMPERATURES EXPECTED AGAIN TOMORROW AFTERNOON
WITH SOME CONVECTION AGAIN BREAKING OUT OVER THE HIGHER TERRAIN.
CONVECTIVE PROBABILITIES SATURDAY WILL DECREASE QUICKLY AS ONE
MOVES AWAY FROM THE MOUNTAINS...SIMILAR TO TODAY.
.LONG TERM...SOME CHANGES AS WE GET INTO NEXT WEEK. UPPER RIDGE
WILL SHIFT EAST ALLOWING FOR MOISTURE TO INCREASE AGAIN BY MONDAY.
MEANWHILE A SHORT WAVE TROUGH MOVING ACROSS THE NORTHERN U.S.
BORDER WILL PUSH SOME LESS HOT LOW LEVEL AIR SOUTHWARD ON MONDAY.
THE MAIN IMPACTS LOOK LIKE THE LOW LEVEL COOLING...AND HIGH LEVEL
MOISTENING. THIS COULD WIND UP BEING SIMILAR TO THE COOLER PERIODS
WE HAD 5 TO 10 DAYS AGO WHEN IT WAS WARM AND MOIST...BUT NOT WARM
ENOUGH TO SUPPORT LOTS OF CONVECTION DUE TO THE CLOUD COVER AND
NOT MUCH COOLING ALOFT. MODELS WANT TO PRODUCE INCREASED
PRECIPITATION IN THE MONDAY THROUGH THURSDAY TIME PERIOD...BUT I
AM HESITANT TO RAISE POPS TOO MUCH DUE TO THE STABILITY ISSUE.
THERE WILL PROBABLY BE MORE CONVECTIVE ACTIVITY...BUT OVERALL IT
WILL LIKELY BE WEAK. POSSIBLE EXCEPTION WILL BE MONDAY WHEN THERE
COULD BE BOTH LOW LEVEL CONVERGENCE AND A LITTLE UPPER LEVEL
DIVERGENCE THAT COULD SUSTAIN SOMETHING MORE ORGANIZED.
TEMPERATURES WILL BE AFFECTED AS MUCH BY THE CLOUD COVER AS THE
ACTUAL COOLING...MINIMUM TEMPERATURES MAY STILL BE PRETTY MILD.
SLIGHT WARMING AND DRYING DURING THE LATER PART OF THE WEEK BUT WE
WILL STILL BE UNDER SW FLOW ALOFT AND PROBABLY STILL A LOT OF HIGH
CLOUDINESS. RIDGE REBUILDS BY NEXT WEEKEND...HARD TO TELL HOW MUCH
CLOUD COVER THERE WILL BE...IF IT DRIES OUT A BIT WE WILL LIKELY
BE NEAR RECORD HIGHS AGAIN...THOUGH PROBABLY NOT AS HOT AS WE ARE
NOW.
&&
.AVIATION...THUNDERSTORM THREAT LOOKS PRETTY SMALL AT THE
TERMINALS THIS EVENING AND AGAIN ON SATURDAY. WINDS ARE BEHAVING
ABOUT AS EXPECTED AT THIS POINT. SOME OF THE SMALLER SCALE MODELS
ARE SUGGESTING A MODERATELY STRONG OUTFLOW BOUNDARY WILL MOVE
ACROSS THE TERMINALS TOWARDS 00Z. PRESENT TAFS HAVE THIS SUGGESTED
WITH THE WESTERLY WINDS AT 00Z. NORMAL DIURNAL PATTERNS LATER
TONIGHT.
&&
.HYDROLOGY...CONVECTIVE ACTIVITY IS MOVING NORTHWARD AT A DECENT
CLIP THIS AFTERNOON. STRONG STORMS MOVED ACROSS THE HIGH PARK BURN
AREA EARLY THIS AFTERNOON AND ADDITIONAL STORMS MAY CROSS THAT
AREA AS WELL AS FOUR MILE LATER TODAY. THESE STORMS WILL POSE SOME
FLOODING THREAT. A SIMILAR SITUATION WILL EXIST SATURDAY
AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...ET
LONG TERM....GIMMESTAD
AVIATION...ET
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
300 PM EDT FRI SEP 6 2013
...STRONG TO POTENTIALLY SEVERE STORMS POSSIBLE LATER THIS AFTERNOON
AND EVENING...
.SHORT TERM...
STRONG TSTMS HAVE BEEN ONGOING ALONG THE SPACE COAST THIS AFTERNOON
WITH A FEW MORE STORMS CURRENTLY OVER PORTIONS OF CITRUS AND
HERNANDO COUNTIES. GROWING INCREASINGLY CONCERNED OVER POTENTIAL OF
STRONG TO SEVERE TSTMS OVER PORTIONS OF THE FORECAST AREA. A
MODERATELY UNSTABLE AIRMASS EXISTS ACROSS THE FLORIDA PENINSULA THIS
AFTERNOON WITH MLCAPE VALUES OF 2000-3000 J/KG. THIS COMBINED WITH A
VERY MOIST BOUNDARY LAYER...AS EVIDENT ON THE MORNING KTBW RAOB
SHOULD ALLOW FOR THE POTENTIAL OF STRONG TO SEVERE TSTM DEVELOPMENT.
EXCESSIVE LIGHTNING...DAMAGING WINDS AND SOME HAIL WILL BE POSSIBLE
ALONG WITH VERY HEAVY RAINFALL. LATEST HRRR MODEL RUN SEEMS TO HAVE
A GRASP ON THE CURRENT CONVECTIVE ACTIVITY OVER THE PENINSULA. IT
SUGGESTS THAT THE BULK OF THE TSTMS CURRENTLY OVER ORANGE...LAKE AND
SEMINOLE COUNTIES WILL GRADUALLY MOVE INTO THE CWA OVER THE NEXT
HOUR OR SO. THE HRRR GUIDANCE SUGGEST THAT A SOMEWHAT LINEAR BAND OF
TSTMS WILL MOVE INTO INTERIOR SECTIONS OF THE AREA AROUND 21-22Z.
THE TAMPA BAY METRO AREA WILL LIKELY SEE ITS BEST CHANCE OF TSTM
ACTIVITY AROUND 23Z AND STORMS SHOULD BEGIN TO EXIT THE COAST AROUND
1-2Z THIS EVENING WITH LINGERING SHOWERS POSSIBLE OVER LAND AREAS
INTO THE EARLY OVERNIGHT HOURS.
SOMEWHAT DRIER AIR WILL MOVE INTO THE AREA TOMORROW WHICH COULD
SERVE AS LIMITING FACTOR FOR SHOWER AND TSTM COVERAGE UNTIL A TAD
LATER INTO THE AFTERNOON. NORTHERN ZONES WILL SEE THE DRIER AIR
FIRST AND BECAUSE OF THIS...LOWER RAIN CHANCES ARE FORECAST FOR THE
NATURE COAST NORTHWARD. STILL FEEL ENOUGH MOISTURE WILL BE IN PLACE
FROM TAMPA BAY SOUTH TO KEEP AROUND 40 POPS IN PLACE.
ON SUNDAY THE DRY AIR BECOMES WELL ESTABLISHED OVER MOST OF THE
REGION. MODELS STILL SHOW SOME POTENTIAL FOR SEA BREEZE INITIATED
STORMS...BUT THE OVERALL COVERAGE SHOULD BE QUITE A BIT LOWER THAN
TODAY AND SATURDAY WITH HIGHEST RAIN CHANCES DOWN SOUTH.
.LONG TERM (MONDAY THROUGH NEXT THURSDAY)...
LONG TERM PERIOD WILL BEGIN NEXT MONDAY WITH A PATTERN DOMINATED BY
LARGE SCALE UPPER RIDGING CENTERED OVER THE SE CONUS. RESIDUAL
ENERGY / WEAK TROUGHING LOOKS TO LINGER FROM OFF THE CAROLINA COAST
SOUTH AND SOUTHWEST TO THE SOUTHERN PORTION OF THE FLORIDA
PENINSULA. WEAK SUPPRESSION FROM THE UPPER RIDGE ALONG WITH THE
ADVECTION OF DRIER AIR DOWN FROM THE NORTH AND NORTHEAST AROUND THE
SYNOPTIC CIRCULATION LOOKS TO BRING SOME LESS FAVORABLE ATMOSPHERIC
CONDITIONS FOR DEEP CONVECTION TO PORTION OF THE AREA DURING THE
FIRST HALF OF THE WORK WEEK. BOTH THE GFS/ECMWF AGREE ON THE DRY AIR
BECOMING ENTRENCHED OVER THE NORTHERN HALF OF THE FORECAST
AREA...HOWEVER THE GFS IS MORE DRAMATIC WITH THIS DRYING...AND ALSO
MORE EXPANSIVE WITH THE DRIER MID-LEVEL AIR TO THE SOUTH.
EITHER WAY...A DECREASE IN THE OVERALL COVERAGE OF SHOWERS AND
STORMS FROM WHAT IS FORECAST OVER THE WEEKEND LOOKS LIKELY. BEST
CHANCES FOR SCATTERED AFTERNOON/EVENING STORMS MONDAY THROUGH
WEDNESDAY EXISTS SOUTH OF I-4...AND ESPECIALLY FROM PUNTA GORDA
SOUTHWARD...WHERE THE MORE "FAVORABLE" MOISTURE PROFILE WILL BE
COINCIDENT WITH EASTERLY LOW LEVEL FLOW TO FOCUS SEA-BREEZE
CONVERGENCE. EVEN STILL...ONLY GOING WITH 30-40% RAIN CHANCES FOR
THESE SOUTHERN ZONES...AND LESSER 20-30% RAIN CHANCES FOR THE
CENTRAL AND NATURE COAST ZONES. WITH THE UPPER RIDGE NEARBY...AND
THE POTENTIAL FOR LESS CONVECTIVE COVERAGE...DAYTIME TEMPS SHOULD
AVERAGE OUT A BIT ABOVE NORMAL.
DURING THE LAST COUPLE DAYS OF THE FORECAST PERIOD...THERE IS SOME
INDICATIONS IN THE GLOBAL GUIDANCE OF A SLOW RETURN OF DEEP MOISTURE
FROM THE EAST AND SOUTHEAST. ONCE AGAIN...THE GFS IS THE MOST
STUBBORN TO HOLD ON TO THE DRIER AIR (ESPECIALLY FROM TAMPA
NORTHWARD)...WHILE THE ECMWF RETURNS THE ENTIRE REGION TO A MORE
FAVORABLE COLUMN FOR DEEP CONVECTION BY FRIDAY. MID/UPPER LEVEL
MOISTURE FIELDS CAN BE SOMEWHAT QUESTIONABLE IN NWP GUIDANCE AT THE
LONGER RANGES...AND CERTAINLY WOULD NOT WANT TO "HANG MY HAT" ON ANY
ONE MODEL SOLUTION. WILL BLEND THE MORE RELIABLE SOLUTION...WHICH
SUGGESTS CHANCE 30-40% POPS FOR BOTH THURSDAY AND FRIDAY. MORE
MOISTURE SUCH AS THE ECMWF ADVERTISES WOULD LEAD TO HIGHER POPS BY
FRIDAY...AND LESS FAVORABLE CONDITIONS AS THE GFS ADVERTISES WOULD
LEAD TO LOWER POPS...ESPECIALLY FOR THE NATURE COAST ZONES.
&&
.AVIATION...
VFR CONDITIONS CURRENTLY PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST
FLORIDA WITH VCTS AT ALL TERMINALS THROUGH 01Z. I HAVE INCLUDED A
TEMPO GROUP FOR BRIEF MVFR/IFR CEILINGS AND VISIBILITIES AT ALL
TERMINAL SITES BETWEEN 06/21Z AND 06/24Z AS SCATTERED SHOWERS AND
STORMS DEVELOP OVER THE REGION. WINDS WILL BE VARIABLE IN VICINITY
OF THUNDERSTORMS WITH POSSIBLE STRONG GUSTS NEAR 40 KNOTS. STORMS
WILL DIMINISH BY 07/01Z...LEAVING PREVAILING VFR CONDITIONS ONCE
AGAIN UNDER A SCT-BKN HIGH LEVEL CIRRUS CANOPY.
&&
.MARINE...
HIGH PRESSURE CONTINUES TO PROVIDE EASTERLY FLOW THROUGH INTO NEXT
WEEK OVER THE WATERS. SHOWERS AND THUNDERSTORMS ARE EXPECTED MOST
DAYS...WITH LATE AFTERNOON AND EVENING THUNDERSTORMS COMING FROM THE
EAST POTENTIALLY CREATING HIGHER WINDS AND WAVES FOR MARINERS.
OTHERWISE...THERE MIGHT BE SOME WINDS AND WAVES NEARING CAUTIONARY
CRITERIA EARLY NEXT WEEK DUE TO OVERNIGHT EASTERLY WIND SURGES.
&&
.FIRE WEATHER...NO SIGNIFICANT FIRE WEATHER PROBLEMS BUT STAGNANT
HIGH PRESSURE OVER THE REGION WILL FAVOR LIGHT WINDS AND LIGHT
TRANSPORT WINDS RESULTING IN LOW DISPERSIONS FOR THE NEXT COUPLE
OF DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 76 92 74 90 / 30 30 20 30
FMY 75 92 74 92 / 40 40 30 40
GIF 74 94 71 93 / 20 30 10 20
SRQ 75 92 73 91 / 30 30 20 30
BKV 70 92 69 92 / 30 30 20 20
SPG 79 90 77 89 / 30 30 20 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...11/MCKAUGHAN
LONG TERM...14/MROCZKA
AVIATION...74/WYNN
MARINE...02/GARCIA
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
158 PM EDT FRI SEP 6 2013
.PREV DISCUSSION...
UPDATE...
/ISSUED 1136 AM EDT FRI SEP 6 2013/
NO CHANGES PLANNED TO THE FORECAST AS ITS ON TRACK. SOMEWHAT
QUESTIONABLE ABOUT THE SLIGHT CHANCE POPS IN THE MOUNTAINS THIS
AFTERNOON AND HRRR ISNT SHOWING ANYTHING DEVELOPING THERE. WITH
POTENTIAL FOR OROGRAPHIC LIFT...WILL LEAVE THE SLIGHT CHANCE IN
THERE FOR NOW AND WATCH TRENDS AS WE MOVE INTO THE AFTERNOON.
11
SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 401 AM EDT FRI SEP 6 2013/
RELATIVELY DRY WX PATTERN TO CONTINUE TODAY AND SATURDAY AS LARGE
UPPER RIDGE CENTERED OVER THE CENTRAL HIGH PLAINS BUILDS EAST...
VERY WEAK NW FLOW PERSISTS OVER THE REGION AND GENERAL LACK OF ANY
SHORT WAVES/FRONTS UPSTREAM IN WESTERLIES OVER GREAT LAKES STATES.
WEAK STATIONARY FRONT OVER SOUTH GA STILL HAVING TROUBLE DECIDING
WHAT TO DO. LOW LEVEL MOISTURE IS HIGHER THAN FCST THIS MORNING
BUT ABSOLUTELY NO SIGN OF PRECIP IN NEARLY ALL MODEL GUIDANCE FOR
TODAY. ONLY THE HIRES WINDOW NMM SHOWS ISOLATED TSRA. HAVE
LOWERED/ DROPPED POPS BUT KEPT THEM AROUND 20PCT IN FAR SOUTHERN
ZONES AND NE GA MOUNTAINS. AS WITH LAST FEW DAYS...ANY TSRA WILL
NOT BE TOO STRONG AND WELL BELOW SEVERE LEVELS. SBCAPE PROGGED
500-1000 J/KG OVER FAR SRN ZONES. NAM AGAIN HAS A BAD CASE OF THE
CRAZIES WITH LACK OF VERTICAL MIXING AND TOO MUCH LOW LEVEL
MOISTURE AND CAPE IN THE AFTERNOON.
IF ONE THINKS TODAYS FCST IS DRY...WAIT TIL SATURDAY WITH NO POPS
FCST. AIRMASS CONTINUES TO DRY. FORTUNATELY TEMPS TO REMAIN JUST
ABOVE NORMAL...WHICH IS NO TOO SHABBY THIS TIME OF YEAR.
SNELSON
LONG TERM /SUNDAY THROUGH THURSDAY/...
/ISSUED 401 AM EDT FRI SEP 6 2013/
UPPER TROUGH MOVING OFF THE NORTHEAST COAST AT THE START OF THE
PERIOD WITH NORTHWEST FLOW CONTINUING ALOFT FOR THE CWA. THIS
SHOULD PUSH ANOTHER WEAK BACK DOOR FRONT INTO THE AREA LATE SUNDAY
EARLY MONDAY. HAVE KEPT LOW POPS IN FOR THIS TIME FRAME BUT
FAVORED THE NORTHERN ZONES. UPPER RIDGE BUILDS EASTWARD INTO THE
FORECAST AREA THROUGH MID WEEK. AFTERNOON HEATING SHOULD BE ABLE
TO TRIGGER A FEW THUNDERSTORMS EACH DAY. BY THE END OF THE WEEK
ANOTHER UPPER TROUGH MOVING ACROSS NEW ENGLAND SHOULD PUSH ANOTHER
BACK DOOR FRONT INTO THE SOUTHERN APPALACHIANS. AN INCREASE IN
DEEPER MOISTURE SHOULD GIVE CHANCE POPS TO THE CWA...FAVORING THE
NORTHERN ZONES. WITH INCREASED THICKNESS ALOFT AFTERNOON MAX
TEMPERATURES SHOULD GENERALLY RANGE MID 80S TO LOW 90S.
41
&&
.AVIATION...
18Z UPDATE...
VFR CONDITIONS EXPECTED THROUGH THIS EVENING. CU FIELD HAS
DEVELOPED ACROSS CSG AND MCN AND WILL CONTINUE TO DEVELOP ACROSS
THE ATL AREA...BUT THESE LOWER CLOUDS WILL DIMINISH AROUND SUNSET.
MAY SEE MVFR CONDITIONS AT AHN AND MCN IN THE MORNING DUE TO FOG.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 66 88 69 / 10 0 5 5
ATLANTA 88 69 88 72 / 10 0 5 5
BLAIRSVILLE 83 61 83 65 / 20 5 10 5
CARTERSVILLE 89 65 88 68 / 10 5 5 5
COLUMBUS 92 70 90 72 / 10 5 5 5
GAINESVILLE 85 66 86 70 / 10 5 5 5
MACON 91 67 90 69 / 10 0 5 5
ROME 90 65 89 68 / 5 5 5 5
PEACHTREE CITY 89 65 88 67 / 10 0 5 5
VIDALIA 90 70 89 72 / 20 10 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...11
LONG TERM....01
AVIATION...11
AREA FORECAST DISCUSSION
NWS POCATELLO ID
154 PM MDT FRI SEP 6 2013
.DISCUSSION...THE SLOW MOVING UPPER LOW OVER THE PAC NW WAS OVER
CENTRAL WA THIS AFTN...AND WILL CONTINUE TO SLOWLY DRIFT E TO THE
ID PANHANDLE BY SUNDAY MORNING. THE SUBTROPICAL MOISTURE PLUME IS
BACKING A LITTLE TO THE WEST TODAY...WHICH WILL PULL THE THREAT OF
TSTMS BACK INTO THE SNAKE RIVER PLAIN ADJACENT TO THE SE HIGHLANDS
THRU THIS EVE. BOTH THE NAM AND HRRR MODELS ARE BOTH PICKING UP ON
THIS. THUNDERSTORMS WILL DECREASE IN COVERAGE LATE THIS EVENING. THE
CYCLE REPEATS ON SATURDAY...AS THE UPPER LOW ONLY MOVES SLIGHTLY
EASTWARD. BY SUNDAY...MOST OF THE SUBTROPICAL MOISTURE MOVES OFF
TO THE EAST...SO ONLY EXPECTING ISOLD TSTMS OVER THE MTNS.
FOR MON THRU WED...THE REGION WILL REMAIN DRY AND WARM AS UPPER
RIDGING BECOMES THE DOMINANT FEATURE. AS THE RIDGE MOVES OFF TO
THE EAST ON THU...SUBTROPICAL MOISTURE ONCE AGAIN HAS A PATH INTO
ID. AS A RESULT...HAVE INCREASED THE TSTM CHANCES FOR THU AND FRI.
HEDGES
&&
.AVIATION...MOISTURE AXIS SEEN ON WV ACROSS SOUTHEAST IDAHO. EXPECT
TO SEE CONVECTION FOCUS ALONG THIS AXIS. MODELS ARE SUGGESTING A
ROUND OF LATE AFTERNOON/EVENING THUNDERSTORMS. HRRR DEVELOPS
CONVECTION ALONG UTAH BORDER AND MOVES IT NORTHEASTWARD ACROSS
KBYI...KPIH AND KIDA. NAM IS HINTING AT SOME CONVECTIVE ACTIVITY IN
THE CENTRAL MOUNTAINS...BUT THERE REMAINS ENOUGH UNCERTAINTY WHEN
COMPARED TO HRRR/LOCAL WRF MODEL TO REMOVE VCTS MENTION AT KSUN
TERMINAL AND REPLACE WITH VCSH. MOISTURE AXIS STAYS OVER SOUTHEAST
IDAHO THROUGH TOMORROW. HAVE KEPT BKN CLOUD COVER THROUGH PERIOD
WITH VCSH STARTING AROUND MID-MORNING AT KPIH AND KIDA. HINSBERGER
&&
.FIRE WEATHER...THUNDERSTORMS WILL DEVELOP ACROSS A MOISTURE BAND
LOCATED ACROSS THE SOUTHEAST HIGHLANDS AND THE SNAKE RIVER PLAIN.
MODELS HINTING THAT THE STRONGEST CHANCES WILL BE DURING THE EVENING
HOURS. MOISTURE WILL REMAIN OVER THE SOUTHEAST HIGHLANDS THROUGH
TOMORROW AS AN UPPER LOW SLOWLY MAKES ITS WAY ACROSS THE PAC NW AND
FINALLY PUSHES OUT OF THE AREA SUNDAY EVENING. SIGNIFICANTLY DRIER
AIR WILL MOVE BACK INTO THE REGION DURING THE FIRST HALF OF NEXT
WEEK AS UPPER RIDGING BUILDS BACK INTO THE PAC NW. AFTER
WEDNESDAY...UPPER RIDGING SHIFTS EASTWARD OPENING UP THE MONSOONAL
FLOW ACROSS THE AREA. THUS WE SHOULD SEE AN INCREASE IN THUNDERSTORM
ACTIVITY TOWARDS THE LATTER HALF OF NEXT WEEK. HINSBERGER
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
413 PM CDT FRI SEP 6 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 145 PM CDT FRI SEP 6 2013
CONFIDENCE LEVEL REMAINS LOW FOR ANY CHGS IN THE SHORT
TERM...ESPECIALLY TONIGHT AS A WEAK COOL FRONT MOVES SOUTHEAST
ACROSS THE REGION...AND STALLS SOUTH OF THE MINNESOTA BORDER
SATURDAY. THE MAIN DILEMMA TONIGHT IS WHETHER SHRA/TSRA DEVELOP
THIS EVENING ALONG A FAIRLY GOOD MOISTURE PLUME THAT IS EVIDENT
ACROSS THE SE FAR FA...WHERE EARLIER SHRA DISSIPATED. IN
ADDITION...AN AREA OF SHRA AND ISOLD TSRA HAVE BEEN MOVING
EASTWARD ACROSS THE DAKOTAS WHICH MAY ALLOW FOR SOME -SHRA ACROSS
WESTERN MN THIS EVENING. HOWEVER...WESTERN MN HAS A GOOD AREA OF
DRYING AT MID LEVELS WHICH SHOULD LIMIT THE CONVECTION POTENTIAL.
THE BEST POTENTIAL REMAINS ACROSS WC WI WHERE CURRENT MLCIN/S ARE
WEAKEST ACROSS THIS REGION ALONG WITH MODEST CAPES. ONLY LIMITING
FACTOR IS THE ORIENTATION OF THE LLJ AND MOISTURE ADVECTION WHICH
IS ACROSS NE WI. FORECASTERS WILL NEED TO CLOSELY WATCH
AFTERNOON/EARLY EVENING CUMULUS FIELD AND HOW IT MAY BUILD TO THE
SW ACROSS WC WI/EC MN. OTHERWISE...THE WEAK COOL FRONT WILL MOVE
SOUTHEAST ACROSS MN BY SATURDAY MORNING. ALTHOUGH DEW PTS WILL
LOWER THROUGHOUT THE DAY ON SATURDAY...THE MAIN CAA WON/T DEVELOP
UNTIL LATE IN THE AFTN/EVENING WHICH MAY ALLOW FOR ANOTHER DAY OF
90S IN THE SOUTH/SW FA. WILL LEAVE CURRENT HIGHS ON SATURDAY THE
SAME BASED ON THIS SCENARIO.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 PM CDT FRI SEP 6 2013
THE PREVAILING PATTERN OF RIDGING IN THE WRN CONUS AND TROFFING IN
THE ERN CONUS WILL BREAK DOWN SUN THROUGH MON AS THE RIDGE
FLATTENS AND SHIFTS E...ALLOWING A FRONTAL SYSTEM TO IMPACT THE
AREA SUN NIGHT THRU MON NIGHT. AT THE SFC...HIGH PRES FROM
W-CENTRAL CANADA WILL DIVE SE THROUGH THE GREAT LAKES WHILE AN
AREA OF LOW PRES GATHERS STRENGTH OVER WY/MT SAT NIGHT INTO SUN.
THIS SYSTEM WILL THEN TRAVERSE ENE THRU SD INTO NRN MN SUN NIGHT
THRU MON WHILE THE UPPER LEVEL PATTERN BECOMES LESS MERIDIONAL AND
MORE ZONAL. A WEAK CDFNT DROPPING THRU THE CWFA SAT WILL RETURN N
AS A WMFNT ON SUN...HELPING AID NOT ONLY AN INCREASE IN THE
MOISTURE COLUMN BUT ALSO AN INCREASE IN TEMPS/INSTABILITY. THOUGH
THE MAIN FOCUS FOR PRECIP SUN NIGHT INTO MON WILL BE N OF THE WFO
MPX CWFA...REMNANTS OF POTENTIAL TSTM CLUSTERS AND/OR MCS
DEVELOPMENT LOOK TO DROP INTO NRN PORTIONS OF THE WFO MPX CWFA BUT
BECAUSE OF GREATER UNCERTAINTY...HAVE DROPPED POPS OUT OF THE
LIKELY CATEGORY AND CAPPED POPS IN THE HIGH CHC RANGE. THE
SECONDARY CDFNT OF THIS SYSTEM WILL DROP THROUGH MON NIGHT INTO
EARLY TUE...BUT THE SFC LOW WILL BECOME LARGELY STRETCHED OUT
WHILE UPPER LEVEL SUPPORT IS RATHER WEAK. THIS WOULD MAKE MON
NIGHT INTO EARLY TUE THE END OF POTENTIAL PRECIP FROM THIS SYSTEM.
THE RIDGE WEST/TROF EAST PATTERN THEN REGAINS CONTROL STARTING TUE
NIGHT AND LINGERS THROUGH FRIDAY. HOWEVER...THOUGH THE UPPER LEVEL
PATTERN WOULD NORMALLY BE CONDUCIVE TO WARMING...THE PRONOUNCED NW
FLOW ALOFT THAT WILL NOT WAVER MUCH WILL BRING IN PIECES OF
MODIFIED CANADIAN AIR TO THE REGION. H85 TEMPS THAT WILL STAY IN
THE 16-20 DEG C RANGE SAT AND SUN...THEN JUMP TO THE MID 20S ON
MON...WILL STEADILY DROP AS THE WEEK PROGRESSES...EVEN POTENTIALLY
HITTING THE SINGLE DIGITS BY THE END OF NEXT WEEK. THIS WILL
TRANSLATE TO THE SFC AS HIGHS ON SUN IN THE MID 70S TO LWR 80S
THAT WILL JUMP TO THE MID 80S TO MID 90S ON MON. ONCE THE
SECONDARY CDFNT DROPS THRU...HIGHS WILL DROP BACK TO THE 70S AND
80S TUE...THEN CONTINUE TO FALL THRU THE WEEK...EVENTUALLY LANDING
IN THE 60S AND 70S BY THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1231 PM CDT FRI SEP 6 2013
MAIN SHORT TERM AVIATION CONCERN IS WHETHER TSRA/SHRA DEVELOP
ALONG AND JUST AHEAD OF A COOL FRONT EXPECTED TO MOVE ACROSS THE
STATE BY MORNING. THERE REMAINS A SMALL REGION OF THETA-E
ADVECTION AND ASSOCIATED MOISTURE POOLING FROM EARLY MORNING SHRA
ACROSS EC MN INTO WC WI. ALTHOUGH WE HAVE MIXED OUT EARLY THIS
AFTN AND NO CUMULUS HAS FORMED...THIS MAY BE TEMPORARY ONCE
MOISTURE LIFTS THE THE LCL/S BY MID/LATE AFTN. LATEST RAP DOES
SUGGEST A SMALL AREA OF MODEST CAPE WITH WEAKENING CIN FROM EC MN
TO WC WI...WITH AN AREA OF PRECIPITATION DEVELOPING ALONG IT.
ALTHOUGH WE HAVE BEEN DRY AND MODELS HAVE BEEN TOO WET
LATELY...THERE REMAINS SOME CONCERN DO TO THE INCREASING MOISTURE
ADVECTION ALREADY NOTED IN SATELLITE IMAGERY. THEREFORE...WILL
UPDATE 18Z TAFS WITH SCT050 AT MSP/RNH/EAU WITH VCSH OR TEMPO AT
EAU WITH -SHRA DURING THE OVERNIGHT PERIOD. ELSEWHERE...TOO DRY AT
LOW LEVELS TO HAVE ANYTHING OTHER THAN MID LEVEL CLOUD COVER. SFC
WINDS WILL DIE OFF BY SUNSET...THEN BECOME NEARLY CALM
OVERNIGHT...THEN BY SUNRISE SHIFT TO THE NE/ENE AS THE FRONT AND
MIXING BEHIND IT DEVELOPS. SOME BR WILL LIKELY FORM NEAR
RNH/EAU/STC...WITH A CHC OF IFR VSBYS AT RNH/EAU IF PRECIPITATION
DEVELOPS THIS EVENING.
KMSP...MAIN CONCERN IS WHETHER ENOUGH MOISTURE AT LOW LEVELS CAN
OVERCOME THE CIN THIS AFTN AND DEVELOP SHRA/TSRA BY EARLY EVENING.
CONFIDENCE REMAINS TOO LOW FOR ANY MAJOR CHGS. HOWEVER...ENOUGH
CONFIDENCE TO BEGIN TO ADD SCT050...WITH POSSIBLY VCSH BY 00-02Z
IF THE ATMOSPHERE CAN OVERCOME THE CIN. OTHERWISE...NO OTHER
AVIATION CONCERNS WITH WINDS DECREASING BY SUNSET...AND BECOMING
MORE NNE/NE AFT 12Z...AND BEGIN TO GUST SATURDAY AFTN.
/OUTLOOK FOR KMSP/
SAT NIGHT...VFR. ENE WINDS 10 KTS.
SUN...VFR. CHC MVFR TRW LATE. ESE WINDS 10-14 KTS.
MON...VFR. CHC MVFR TRW. S WINDS 8-12 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...JPC
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
203 PM CDT FRI SEP 6 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 145 PM CDT FRI SEP 6 2013
CONFIDENCE LEVEL REMAINS LOW FOR ANY CHGS IN THE SHORT
TERM...ESPECIALLY TONIGHT AS A WEAK COOL FRONT MOVES SOUTHEAST
ACROSS THE REGION...AND STALLS SOUTH OF THE MINNESOTA BORDER
SATURDAY. THE MAIN DILEMMA TONIGHT IS WHETHER SHRA/TSRA DEVELOP
THIS EVENIGN ALONG A FAIRLY GOOD MOISTURE PLUME THAT IS EVIDENT
ACROSS THE SE FAR FA...WHERE EARLIER SHRA DISSIPATED. IN
ADDITION...AN AREA OF SHRA AND ISOLD TSRA HAVE BEEN MOVING
EASTWARD ACROSS THE DAKOTAS WHICH MAY ALLOW FOR SOME -SHRA ACROSS
WESTERN MN THIS EVENING. HOWEVER...WESTERN MN HAS A GOOD AREA OF
DRYING AT MID LEVELS WHICH SHOULD LIMIT THE CONVECTION POTENTIAL.
THE BEST POTENTIAL REMAINS ACROSS WC WI WHERE CURRENT MLCIN/S ARE
WEAKEST ACROSS THIS REGION ALONG WITH MODEST CAPES. ONLY LIMITING
FACTOR IS THE ORIENTATION OF THE LLJ AND MOISTURE ADVECTION
WHICH IS ACROSS NE WI. FORECASTERS WILL NEED TO CLOSELY WATCH
AFTERNOON/EARLY EVENING CUMULUS FIELD AND HOW IT MAY BUILD TO THE
SW ACROSS WC WI/EC MN. OTHERWISE...THE WEAK COOL FRONT WILL MOVE
SOUTHEAST ACROSS MN BY SATURDAY MORNING. ALTHOUGH DEW PTS WILL
LOWER THROUGHOUT THE DAY ON SATURDAY...THE MAIN CAA WON/T DEVELOP
UNTIL LATE IN THE AFTN/EVENING WHICH MAY ALLOW FOR ANOTHER DAY OF
90S IN THE SOUTH/SW FA. WILL LEAVE CURRENT HIGHS ON SATURDAY THE
SAME BASED ON THIS SCENARIO.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI SEP 6 2013
RIDGING ALOFT WILL DOMINATE THE REGION THROUGH MONDAY WITH AN
UPPER TROUGH MOVING THROUGH TUESDAY AND WEDNESDAY. THE TROUGH IS
THE REMNANTS OF THE CUT-OFF LOW CURRENTLY OVER THE PACIFIC
NORTHWEST. THE GEM/GFS AND ECMWF ARE IN REALLY GOOD AGREEMENT WITH
THE HEIGHT PATTERN ALOFT THROUGH THE EXTENDED PERIOD.
THE MAIN CONCERNS FOR THE LONGER TERM ARE PRECIPITATION CHANCES
SUNDAY NIGHT AND HIGH TEMPERATURES ON MONDAY. A COOL FRONT THAT
MOVES EAST AND SOUTH OF THE FA ON SATURDAY WILL RETURN SUNDAY
NIGHT AS A WARM FRONT. THE FOCUS OF MOISTURE TRANSPORT...
DIFFERENTIAL TEMPERATURE ADVECTION AND DIFFERENTIAL DIVERGENCE
POINT TO AN MCS FORMING OVER THE DAKOTAS AND MOVING ACROSS
NORTHERN MN DURING THE NIGHT. HIGH CHANCE TO LIKELY POPS LOOK
APPROPRIATE ACROSS CENTRAL MN AND PORTIONS OF WEST CENTRAL WI BUT
REALLY WONDER IF ANYTHING AT ALL WILL OCCUR ACROSS SOUTHERN MN.
TRIED TO MINIMIZE POPS IN THE SOUTH AS MUCH AS POSSIBLE AND REMAIN
IN COLLABORATION. THIS LEADS INTO MONDAY WHEN A SOUTHWEST SURFACE WIND
WILL DEVELOP IN THE WAKE OF THE WARM FRONT. 850 MB TEMPERATURES ON
THE GFS AND ECMWF REMAIN CONSISTENT WITH 22-26 DEG C BLASTING
ACROSS THE FA BY MIDDAY. MIX DOWN YIELDS HIGHS IN THE MIDDLE TO
UPPER 90S... WHICH IS CLOSE THE ECMWF MAX TEMP FORECAST. THE EC
WAS THE HIGHEST OF ALL OF THE GUIDANCE. BLENDED THE MIX-DOWN WITH
THE CR EXTEND... WHICH PLACED HIGHS IN THE TWIN CITIES INTO THE LOWER
90S. THIS STILL MAY NOT BE ENOUGH. THE NORTHERN AND EASTERN
PERIPHERIES OF THE CWA ARE MORE PRONE TO SOME CLOUDINESS AND
THEREFORE CUT HIGHS BACK SOME TO STAY IN COLLABORATION WITH OUR
NEIGHBORS. FORTUNATELY... DEW POINTS ARE EXPECTED TO ONLY BE IN
THE MIDDLE 60S ON MONDAY. THIS RESULTS IN HEAT INDICES TO AROUND
95 DEGREES.
THE THREAT FOR SHOWERS AND THUNDERSTORMS INCREASE MONDAY NIGHT AS
THE AFOREMENTIONED TROUGH ALOFT APPROACHES FROM THE WEST ALONG
WITH A COLD FRONT. CAPPING ALOFT WILL GIVE WAY TO HEIGHT FALLS AND
COOLER TEMPERATURES WITH PRETTY GOOD CHANCES FOR RAIN DURING THE NIGHT.
COOLER AND DRIER WEATHER PREVAILS IN THE WAKE OF THE FRONT FROM
TUESDAY THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1231 PM CDT FRI SEP 6 2013
MAIN SHORT TERM AVIATION CONCERN IS WHETHER TSRA/SHRA DEVELOP
ALONG AND JUST AHEAD OF A COOL FRONT EXPECTED TO MOVE ACROSS THE
STATE BY MORNING. THERE REMAINS A SMALL REGION OF THETA-E
ADVECTION AND ASSOCIATED MOISTURE POOLING FROM EARLY MORNING SHRA
ACROSS EC MN INTO WC WI. ALTHOUGH WE HAVE MIXED OUT EARLY THIS
AFTN AND NO CUMULUS HAS FORMED...THIS MAY BE TEMPORARY ONCE
MOISTURE LIFTS THE THE LCL/S BY MID/LATE AFTN. LATEST RAP DOES
SUGGEST A SMALL AREA OF MODEST CAPE WITH WEAKENING CIN FROM EC MN
TO WC WI...WITH AN AREA OF PRECIPITATION DEVELOPING ALONG IT.
ALTHOUGH WE HAVE BEEN DRY AND MODELS HAVE BEEN TOO WET
LATELY...THERE REMAINS SOME CONCERN DO TO THE INCREASING MOISTURE
ADVECTION ALREADY NOTED IN SATELLITE IMAGERY. THEREFORE...WILL
UPDATE 18Z TAFS WITH SCT050 AT MSP/RNH/EAU WITH VCSH OR TEMPO AT
EAU WITH -SHRA DURING THE OVERNIGHT PERIOD. ELSEWHERE...TOO DRY AT
LOW LEVELS TO HAVE ANYTHING OTHER THAN MID LEVEL CLOUD COVER. SFC
WINDS WILL DIE OFF BY SUNSET...THEN BECOME NEARLY CALM
OVERNIGHT...THEN BY SUNRISE SHIFT TO THE NE/ENE AS THE FRONT AND
MIXING BEHIND IT DEVELOPS. SOME BR WILL LIKELY FORM NEAR
RNH/EAU/STC...WITH A CHC OF IFR VSBYS AT RNH/EAU IF PRECIPITATION
DEVELOPS THIS EVENING.
KMSP...
MAIN CONCERN IS WHETHER ENOUGH MOISTURE AT LOW LEVELS CAN OVERCOME
THE CIN THIS AFTN AND DEVELOP SHRA/TSRA BY EARLY EVENING.
CONFIDENCE REMAINS TOO LOW FOR ANY MAJOR CHGS. HOWEVER...ENOUGH
CONFIDENCE TO BEGIN TO ADD SCT050...WITH POSSIBLY VCSH BY 00-02Z
IF THE ATMOSPHERE CAN OVERCOME THE CIN. OTHERWISE...NO OTHER
AVIATION CONCERNS WITH WINDS DECREASING BY SUNSET...AND BECOMING
MORE NNE/NE AFT 12Z...AND BEGIN TO GUST SATURDAY AFTN.
/OUTLOOK FOR KMSP/
SAT NIGHT...VFR. ENE WINDS 10 KTS.
SUN...VFR. CHC MVFR TRW LATE. ESE WINDS 10-14 KTS.
MON...VFR. CHC MVFR TRW. S WINDS 8-12 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...RAH
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1248 PM CDT FRI SEP 6 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT FRI SEP 6 2013
COMBINATION OF WEAK WAA AND MOISTURE TRANSPORT IN THE H85-H7 LAYER
OVERNIGHT HAS RESULTED IN AREA OF ACCUS WITH A FEW ISO SHOWERS
MOVING ACROSS SRN MN THROUGH THE NIGHT. HIGH-RES CAMS ALL FAIRLY
SIMILAR WITH AN AREA OF ISO-SCT SHOWERS BLOSSOMING NEAR THE I-35
CORRIDOR FROM THE TWIN CITIES SOUTH NEAR SUNRISE. AFTER
SUNRISE...WHAT LITTLE ACTIVITY THERE IS SHOULD DIMINISH QUICKLY AS
LLJ DRIVING THIS WEAKENS SOME...SO HAVE ANY SMALL POPS MENTIONED
UNTIL 15Z.
IN THE WAKE OF THIS SYSTEM...SW WINDS WILL RESULT IN 925-850 MB
TEMPS INCREASING TO AROUND 22C IN THE EAST AND 26C IN THE WEST.
SIMILAR TEMPERATURES IN THIS LAYER YESTERDAY RESULTED IN HIGHS IN
THE UPPER 80S TO LOWER 90S OUT IN THE DAKOTAS...SO HAVE HIGHS
LOOKING PRETTY MUCH THE SAME FROM EAST TO WEST ACROSS THE MPX AREA
TODAY. THOUGH THESE HIGHS ARE NEARLY 15 DEGREES ABOVE NORMAL...
RECORD HIGHS TODAY SHOULD BE SAFE WITH THE NUMBERS TO BEAT SITTING
AT 95 IN STC...98 AT MSP...AND 100 IN EAU. WITH DEWPS INCREASING
BACK INTO THE MID/UPPER 60S...WILL SEE HEAT INDICES THIS AFTERNOON
PEAKING BACK UP IN THE MID 90S...WITH LOWS OVERNIGHT ONLY FALLING
BACK INTO THE MID 60S AT BEST.
THE TROUGH MENTIONED IN THE SYNOPSIS OUT TO THE WEST WILL EVOLVE
INTO A WEAK COLD FRONT THIS AFTERNOON THAT WILL BEGIN TO WORK ACROSS
THE AREA OVERNIGHT. THE WARM TEMPERATURES MOVING IN TODAY ALOFT WILL
ALSO BRING IN A STRONG CAPPING INVERSION THAT LOOKS TO KEEP THE MN
PORTION OF THE MPX CWA DRY WITH ANY ACTIVITY CONFINED TO THE
PERIPHERY OF THE CAP...WHICH WOULD MEAN ANOTHER NIGHT OF WATCHING
ACTIVITY WORKING FROM NE MN INTO CENTRAL WI. LIKE TONIGHT...WEAK
WARM ADVECTION AND MOISTURE TRANSPORT IN THE H85-H7 LAYER WILL FIND
ITS WAY OVER TO WI OUT AHEAD OF THE FRONT. AS A RESULT...A FEW OF
THE HI-RES CAMS SHOW SOME THUNDERSTORMS WORKING ACROSS WRN WI FRIDAY
NIGHT. HOWEVER...WITH WARM TEMPS ALOFT AND WEAK SHORTWAVE DRIVING
THIS CONVECTION GOING ACROSS LAKE SUPERIOR...CONFIDENCE IS NOT ALL
THAT HIGH THAT SOME MUCH NEEDED RAINS WILL BE SEEN IN THE ERN MPX
CWA SO HAVE ONLY SLIGHT CHANCES MENTIONED AT THIS POINT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI SEP 6 2013
RIDGING ALOFT WILL DOMINATE THE REGION THROUGH MONDAY WITH AN
UPPER TROUGH MOVING THROUGH TUESDAY AND WEDNESDAY. THE TROUGH IS
THE REMNANTS OF THE CUT-OFF LOW CURRENTLY OVER THE PACIFIC
NORTHWEST. THE GEM/GFS AND ECMWF ARE IN REALLY GOOD AGREEMENT WITH
THE HEIGHT PATTERN ALOFT THROUGH THE EXTENDED PERIOD.
THE MAIN CONCERNS FOR THE LONGER TERM ARE PRECIPITATION CHANCES
SUNDAY NIGHT AND HIGH TEMPERATURES ON MONDAY. A COOL FRONT THAT
MOVES EAST AND SOUTH OF THE FA ON SATURDAY WILL RETURN SUNDAY
NIGHT AS A WARM FRONT. THE FOCUS OF MOISTURE TRANSPORT...
DIFFERENTIAL TEMPERATURE ADVECTION AND DIFFERENTIAL DIVERGENCE
POINT TO AN MCS FORMING OVER THE DAKOTAS AND MOVING ACROSS
NORTHERN MN DURING THE NIGHT. HIGH CHANCE TO LIKELY POPS LOOK
APPROPRIATE ACROSS CENTRAL MN AND PORTIONS OF WEST CENTRAL WI BUT
REALLY WONDER IF ANYTHING AT ALL WILL OCCUR ACROSS SOUTHERN MN.
TRIED TO MINIMIZE POPS IN THE SOUTH AS MUCH AS POSSIBLE AND REMAIN
IN COLLABORATION. THIS LEADS INTO MONDAY WHEN A SOUTHWEST SURFACE WIND
WILL DEVELOP IN THE WAKE OF THE WARM FRONT. 850 MB TEMPERATURES ON
THE GFS AND ECMWF REMAIN CONSISTENT WITH 22-26 DEG C BLASTING
ACROSS THE FA BY MIDDAY. MIX DOWN YIELDS HIGHS IN THE MIDDLE TO
UPPER 90S... WHICH IS CLOSE THE ECMWF MAX TEMP FORECAST. THE EC
WAS THE HIGHEST OF ALL OF THE GUIDANCE. BLENDED THE MIX-DOWN WITH
THE CR EXTEND... WHICH PLACED HIGHS IN THE TWIN CITIES INTO THE LOWER
90S. THIS STILL MAY NOT BE ENOUGH. THE NORTHERN AND EASTERN
PERIPHERIES OF THE CWA ARE MORE PRONE TO SOME CLOUDINESS AND
THEREFORE CUT HIGHS BACK SOME TO STAY IN COLLABORATION WITH OUR
NEIGHBORS. FORTUNATELY... DEW POINTS ARE EXPECTED TO ONLY BE IN
THE MIDDLE 60S ON MONDAY. THIS RESULTS IN HEAT INDICES TO AROUND
95 DEGREES.
THE THREAT FOR SHOWERS AND THUNDERSTORMS INCREASE MONDAY NIGHT AS
THE AFOREMENTIONED TROUGH ALOFT APPROACHES FROM THE WEST ALONG
WITH A COLD FRONT. CAPPING ALOFT WILL GIVE WAY TO HEIGHT FALLS AND
COOLER TEMPERATURES WITH PRETTY GOOD CHANCES FOR RAIN DURING THE NIGHT.
COOLER AND DRIER WEATHER PREVAILS IN THE WAKE OF THE FRONT FROM
TUESDAY THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1231 PM CDT FRI SEP 6 2013
MAIN SHORT TERM AVIATION CONCERN IS WHETHER TSRA/SHRA DEVELOP
ALONG AND JUST AHEAD OF A COOL FRONT EXPECTED TO MOVE ACROSS THE
STATE BY MORNING. THERE REMAINS A SMALL REGION OF THETA-E
ADVECTION AND ASSOCIATED MOISTURE POOLING FROM EARLY MORNING SHRA
ACROSS EC MN INTO WC WI. ALTHOUGH WE HAVE MIXED OUT EARLY THIS
AFTN AND NO CUMULUS HAS FORMED...THIS MAY BE TEMPORARY ONCE
MOISTURE LIFTS THE THE LCL/S BY MID/LATE AFTN. LATEST RAP DOES
SUGGEST A SMALL AREA OF MODEST CAPE WITH WEAKENING CIN FROM EC MN
TO WC WI...WITH AN AREA OF PRECIPITATION DEVELOPING ALONG IT.
ALTHOUGH WE HAVE BEEN DRY AND MODELS HAVE BEEN TOO WET
LATELY...THERE REMAINS SOME CONCERN DO TO THE INCREASING MOISTURE
ADVECTION ALREADY NOTED IN SATELLITE IMAGERY. THEREFORE...WILL
UPDATE 18Z TAFS WITH SCT050 AT MSP/RNH/EAU WITH VCSH OR TEMPO AT
EAU WITH -SHRA DURING THE OVERNIGHT PERIOD. ELSEWHERE...TOO DRY AT
LOW LEVELS TO HAVE ANYTHING OTHER THAN MID LEVEL CLOUD COVER. SFC
WINDS WILL DIE OFF BY SUNSET...THEN BECOME NEARLY CALM
OVERNIGHT...THEN BY SUNRISE SHIFT TO THE NE/ENE AS THE FRONT AND
MIXING BEHIND IT DEVELOPS. SOME BR WILL LIKELY FORM NEAR
RNH/EAU/STC...WITH A CHC OF IFR VSBYS AT RNH/EAU IF PRECIPITATION
DEVELOPS THIS EVENING.
KMSP...
MAIN CONCERN IS WHETHER ENOUGH MOISTURE AT LOW LEVELS CAN OVERCOME
THE CIN THIS AFTN AND DEVELOP SHRA/TSRA BY EARLY EVENING.
CONFIDENCE REMAINS TOO LOW FOR ANY MAJOR CHGS. HOWEVER...ENOUGH
CONFIDENCE TO BEGIN TO ADD SCT050...WITH POSSIBLY VCSH BY 00-02Z
IF THE ATMOSPHERE CAN OVERCOME THE CIN. OTHERWISE...NO OTHER
AVIATION CONCERNS WITH WINDS DECREASING BY SUNSET...AND BECOMING
MORE NNE/NE AFT 12Z...AND BEGIN TO GUST SATURDAY AFTN.
/OUTLOOK FOR KMSP/
SAT NIGHT...VFR. ENE WINDS 10 KTS.
SUN...VFR. CHC MVFR TRW LATE. ESE WINDS 10-14 KTS.
MON...VFR. CHC MVFR TRW. S WINDS 8-12 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SYNOPSIS...MPG
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
620 PM EDT FRI SEP 6 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL DROP ACROSS THE AREA THIS WEEKEND
THEN OFFSHORE BY LATE SUNDAY. A WEAK COLD FRONT WILL DISSIPATE
OVER THE REGION LATE MONDAY...FOLLOWED BY HIGH PRESSURE THROUGH
MID-WEEK. A COLD FRONT IS EXPECTED TO CROSS THE AREA NEXT FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 615 PM FRIDAY...THE FORECASTS HAS BEEN UPDATED A LITTLE EARLY
TO ACCOUNT FOR A CLUSTER OF THUNDERSTORMS MOVING SOUTHWESTWARD DOWN
THE COAST OF NORTH CAROLINA...NOW APPROACHING SURF CITY. THIS
ACTIVITY IS ROOTED WITHIN A NARROW ZONE OF FAIRLY SUBSTANTIAL
SURFACE-BASED INSTABILITY (CAPE NEARLY 2000 J/KG) RIGHT ALONG THE
COAST WHERE DEWPOINTS HAVE RECOVERED TO 70-72 DEGREES DUE TO THE
AFTERNOON SEABREEZE. ON THE WEST (INLAND) SIDE OF THE SEABREEZE
WHERE DEWPOINTS ARE 7-10 DEGREES LOWER THERE IS NEGLIGIBLE
SURFACE-BASED CAPE AND VIRTUALLY NO CHANCE OF PRECIPITATION THIS
EVENING.
THE LATEST THREE HRRR RUNS SHOW THERE IS POTENTIAL FOR THIS
CONVECTION TO CONTINUE ALL THE WAY DOWN TO SOUTHPORT. 0-6 KM BULK
SHEAR IS NEAR 30 KNOTS WHICH IS SUPPORTING THE MULTICELLULAR
CHARACTERISTICS WE ARE OBSERVING. PRECIPITABLE WATER ONLY AROUND 1.3
INCHES...KEPT LOW BY ALL THE DRY AIR IN THE MID LEVELS...IS
OFFSETTING WHAT COULD BE A SERIOUS FLOODING THREAT GIVEN THE SLOW
OBSERVED STORM MOTION. I HAVE INCREASED FORECAST POPS ALONG THE CAPE
FEAR COASTLINE THROUGH ABOUT 02Z...WITH CHANCES FOR PRECIPITATION
DROPPING BELOW MENTIONABLE THRESHOLDS BY MIDNIGHT EVERYWHERE ON
LAND.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO OTHER FORECAST VARIABLES AT
THIS TIME. PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
ONE ONLY NEEDS TO LOOK AT THE VISIBLE
SATELLITE IMAGERY COMBINED WITH SURFACE OBS THIS AFTN TO UNDERSTAND
THE SYNOPTIC ENVIRONMENT. TEMPS IN THE UPPER 80S BUT WITH ONLY
SCATTERED SHALLOW CU DEVELOPMENT IS A CLEAR INDICATOR OF DRY HIGH
PRESSURE BUILDING INTO THE AREA. THIS IS BEHIND A COLD FRONT WHICH
HAS SUNK WELL SOUTH OF THE CWA...AND THIS HIGH PRESSURE WILL
CONTINUE TO RIDGE DOWN THE COAST THROUGH TONIGHT. WHILE SURFACE HIGH
PRESSURE WILL ACT TO INHIBIT MUCH CONVECTION TODAY...MID-LEVEL
SHORTWAVE ROTATING AROUND LONGWAVE TROUGH HAS THE POTENTIAL TO
CREATE SOME ISOLATED SHOWERS THIS EVENING AND TONIGHT.
HIGH RES GUIDANCE (WRF/HRRR) CONTINUES TO SUGGEST THAT SCATTERED
SHOWERS WILL DEVELOP NORTH OF THE LOCAL AREA THIS EVENING AND ADVECT
SOUTH INTO THE NORTHERN ZONES TONIGHT. HAVE NOTICED THAT THESE
MODELS ARE INITIALIZING "HOT" HOWEVER...AND THE CONVECTION PROGGED
TO BE ONGOING AT THE PRESENT TIME HAS NOT MATERIALIZED.
STILL...FORECAST SOUNDINGS SUGGEST AMPLE MOISTENING OF THE
1000-800MB LAYER TONIGHT WHICH COMBINED WITH SOME MID-LEVEL FORCING
BENEATH THE SHORTWAVE COULD GENERATE A SHOWER OR TWO...CONFINED TO
THE NORTHEAST PORTIONS OF THE CWA. HAVE CAPPED POP AT
SCHC/ISOLATED...AND SIGNIFICANT DRY AIR ABOVE 700MB WILL INHIBIT
CONVECTION FROM BECOMING STRONG...THUS DO NOT EVEN ANTICIPATE
LIGHTNING. AT THE VERY LEAST...SOME ENHANCED MID LEVEL CLOUD COVER
IS EXPECTED TO DROP SOUTH TO NORTH TONIGHT.
MINS TONIGHT WILL BE A LITTLE TRICKY WITH CONTINUED NE WINDS AND THE
POTENTIALLY ENHANCED CLOUD COVER...ESPECIALLY IN THE N/NE ZONES.
HAVE KEPT MINS SLIGHTLY ABOVE GUIDANCE...SIDING MORE WITH THE WARMER
MET NUMBERS...WHICH HAS GENERALLY PERFORMED BETTER THAN THE MAV THIS
MONTH.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...MAIN FEATURE OF NOTE SATURDAY AND SUNDAY IS
CANADIAN HIGH PRESSURE DROPPING SE ACROSS THE EASTERN CAROLINAS
SATURDAY THEN OFFSHORE BY LATE SUNDAY. NE-E WIND FLOW IN THE
LOWEST SEVERAL THOUSAND FEET OF THE ATMOSPHERE SATURDAY COULD
BRING A MODERATE AMOUNT OF STRATO-CUMULUS SO CERTAINLY DO NOT
WANT TO ADVERTISE ALL OUT "SUNNY". SPOTTY LIGHT SHOWERS CANNOT
BE RULED OUT ALONG THE NORTH COAST AROUND DAYBREAK SATURDAY BUT
WEAK SUBSIDENCE IN WAKE OF AN IMPULSE MOVING SE AND OFFSHORE
SHOULD CONFINE SHOWERS SATURDAY OVER THE 0-20 NM COASTAL WATERS
AND NORTH TO CAPE LOOKOUT. AS THE HIGH MOVES OFFSHORE LATE ON
SUNDAY...A WEAK SHORT-WAVE AND BRIEF SURFACE TROUGH INLAND MAY
TRIP OFF A FEW SHOWERS SUNDAY AFTERNOON AND EVENING. AS THIS
FEATURE DROPS SOUTH OF THE AREA...THE LEADING EDGE OF CANADIAN
HIGH PRESSURE PUSHES A WEAK BACK DOOR FRONT SOUTH INTO OUR NC
ZONES. SUBSIDENCE ALOFT APPEARS TO ACCOMPANY THIS FEATURE WITH
DRY NORTH FLOW ALOFT AND NO MENTIONABLE POPS PLANNED EARLY MON.
SUNDAY MORNING SHOULD BE A FEW DEGREES COOLER THAN SAT MORNING
MAINLY BY VIRTUE OF LESS CLOUDS...WITH WIDESPREAD 60S EXPECTED
DAYBREAK SUNDAY. MAXIMUMS TEMPS SHOULD BE WARMER ON SUNDAY FOR
SIMILAR REASONS OF LESS CLOUD COVER. RETURN FLOW BEGINS LATE
SUNDAY EVENING WITH A WEAK WIND SHIFT TO NORTH OVER OUR NC
ZONES INTO DAYBREAK MONDAY AS THE CANADIAN HIGH DIPS INTO THE
MID-ATLANTIC REGION.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...MID LEVEL RIDGING WILL BE THE PREVAILING
FEATURE FOR THE FIRST HALF OF THE FORECAST PERIOD. THERE WILL BE
SUFFICIENT MOISTURE IN THE COLUMN...PRECIPITABLE WATER VALUES OF
1.80 INCHES... TO MAINTAIN SLIGHT CHANCE POPS MONDAY BEFORE A
SURGE OF DRIER AIR MOVES IN FROM THE NORTHEAST. THIS WILL KEEP
POPS OUT OF THE PICTURE FOR TUESDAY AND WEDNESDAY. A SIGNIFICANT
MID LEVEL TROUGH WILL BRING ANOTHER RELATIVELY STRONG COLD FRONT
ACROSS THE AREA FRIDAY. THE SOUTHERLY FLOW AHEAD OF THIS SYSTEM
WILL ALLOW SLIGHT CHANCE POPS TO CREEP BACK INTO THE FORECAST
THURSDAY WITH THE BETTER FORCING WARRANTING CHANCE VALUES FRIDAY.
TEMPERATURE FORECAST LOOKS STABLE WITH VALUES JUST A DEGREE OR TWO
ABOVE CLIMATOLOGY THROUGH THE PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...TERMINALS ARE VFR THIS AFTERNOON AND VFR IS EXPECTED
THIS TAF VALID PERIOD...EXCEPT FROM MIDNIGHT UNTIL JUST AFTER
SUNRISE. AN UPPER IMPULSE WILL PASS LATE THIS AFTERNOON. HIGH
RESOLUTION MODELS CONTINUE TO INDICATE SHOWERS AND POSSIBLY AN
ISOLATED THUNDERSTORM MOVING SOUTHWEST TOWARDS MAINLY KILM. WILL
INDICATE VCSH LATER THIS AFTERNOON ONLY AT KILM WHERE A RESULTANT
BOUNDARY WILL INTERACT WITH THE IMPULSE AT MAX HEATING. SINCE ANY
THUNDERSTORM IS EXPECTED TO BE ISOLATED THERE IS LOW CONFIDENCE OF
VCTS. VCSH WILL END 01-02Z.
MODELS SOUNDINGS ARE INDICATING SUFFICIENT LOW-LEVEL MOISTURE TO
PRODUCE MVFR/IFR CONDITIONS AFTER 06Z. MVFR WILL POSSIBLY OCCUR AT
KILM/KCRE/KMYR ALTHOUGH BEST CONFIDENCE OF OCCURRENCE WILL BE AT
KMYR. THE BEST CHANCE OF IFR WILL BE AT KFLO...AND TO A LESSER
EXTENT KLBT. VFR EXPECTED AFTER 14Z AT ALL TERMINALS WITH NE-ENE
WINDS.
EXTENDED OUTLOOK...MORNING FOG/STRATUS IS POSSIBLE THROUGH THE
EXTENDED PERIOD. SLIGHT CHANCE OF SHOWERS SUNDAY NIGHT THROUGH
TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 615 PM FRIDAY...I HAVE UPDATED THE MARINE FORECAST TO INCREASE
THE POTENTIAL OF THUNDERSTORMS THIS EVENING...MAINLY FROM AROUND
CAPE FEAR NORTH TO SURF CITY. LATEST NEAR-TERM HIGH RESOLUTION
MODELS SHOW THE THUNDERSTORM ACTIVITY APPROACHING SURF CITY MAY MAKE
IT DOWN TO SOUTHPORT OVER THE NEXT 2-3 HOURS. AFTER REVIEWING THE
LATEST SYNOPTIC MODELS FOR THE OVERNIGHT PERIOD I HAVE INCREASED
WIND SPEED FORECASTS BY A FEW KNOTS AFTER MIDNIGHT AND HAVE BACKED
WIND DIRECTIONS BY ABOUT 30 DEGREES...MORE NORTHEAST THAN EAST.
PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
HIGH PRESSURE BUILDING SOUTH FROM THE MID-ATLANTIC WILL CONTINUE TO
RIDGE ACROSS THE WATERS TONIGHT...PERSISTING THE NE WINDS PRESENTLY
OBSERVED AT THE LOCAL BUOYS. WHILE WINDS HAVE BEEN AROUND 10 KTS
MUCH OF THE DAY...A MDT NE SURGE IS STILL PROGGED TONIGHT...DRIVING
WINDS UP TO AROUND 15 KTS LATE IN THE PERIOD. THESE WINDS WILL FORCE
RISING WAVE HEIGHTS...FROM 1-3 FT...UP TO 3-4 FT LATE TONIGHT WITH A
5 SEC NE WIND CHOP REMAINING DOMINANT WITHIN THE WAVE SPECTRUM.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...MODERATE NE WINDS CAN BE EXPECTED ON THE
WATERS SATURDAY AS CANADIAN HIGH PRESSURE DROPS SE TOWARD THE
COASTAL WATERS. THIS MAY BRING SEAS TO 4 FEET OVER THE OUTER
WATERS AND ALSO NORTH OF CAPE FEAR...BUT NO ADVISORIES OR TSTMS
ARE EXPECTED. LIGHT SHOWERS HOWEVER MAY DOT THE WATERS SATURDAY
AND MAINLY NORTH OF CAPE FEAR. WINDS WILL EASE AND BECOME LIGHT
SATURDAY NIGHT AND SUNDAY AS THE HIGH MOVES NEARLY OVERHEAD OF
THE WATERS. AS THE HIGH MOVES OFFSHORE SUNDAY EVENING...EXPECT
WINDS TO BECOME S AND SW. HIGHEST WINDS AND SEAS ARE ANTICIPATED
SATURDAY WITH OVERALL IMPROVING CONDITIONS LATE SATURDAY AND
SUNDAY. LATE SUNDAY NIGHT INTO EARLY MONDAY HIGH PRESSURE DROPPING
FROM THE NORTH WILL BRING A WEAK COLD FRONT TO THE NC WATERS. THIS
SHOULD BRING A WIND-SHIFT NORTH OF CAPE FEAR BY DAYBREAK MONDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...EASTERLY WINDS INITIALLY WILL BACK TO
NORTHEASTERLY LATE MONDAY AND VACILLATE BETWEEN EAST TO NORTHEAST
THROUGH WEDNESDAY. THERE MAY BE A LATE SHIFT VERY LATE IN THE PERIOD
WEDNESDAY TO SOUTHEAST AS THE PATTERN SHIFTS A BIT BUT THIS WILL
NEED TO BE FINE TUNED IN SUBSEQUENT FORECASTS. WIND SPEEDS WILL
REMAIN EITHER SIDE OF TEN KNOTS THROUGHOUT THE PERIOD. WAVEWATCH
SEAS CONTINUE THE SEEMINGLY SUMMER LONG TREND OF BENIGN SEAS WITH
2-3 FEET PRIMARILY COMPRISED OF SHORTER PERIOD WIND WAVES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...8
NEAR TERM...JDW/TRA
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...MRR/JDW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1234 PM CDT FRI SEP 6 2013
.UPDATE...
ISSUED AT 1234 PM CDT FRI SEP 6 2013
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO TRACK
ACROSS CENTRAL NORTH DAKOTA. 15 UTC HRRR SHOWS THE AREA OF SHOWERS
AROUND BISMARCK HOLDING TOGETHER THROUGH THE JAMESTOWN AREA.
ALTHOUGH LITTLE MORE THAN A FEW SPRINKLES CAN BE EXPECTED MOST
AREAS...THE INCREASED CLOUD COVER WILL LIKELY KEEP TEMPERATURES
FROM REACHING FORECAST HIGHS...THEREFORE WE LOWERED MAXIMUM
TEMPERATURES 2-5 DEGREES MOST AREAS. SURFACE DEW POINTS REMAIN IN
THE MID TO UPPER 60S WHICH IS A LITTLE HIGHER THAN FORECAST. THUS
EVEN THOUGH WE MAY NOT QUITE REACH OUR FORECAST HIGHS...WITH THE
ADDED MOISTURE...IT WILL REMAIN QUITE UNCOMFORTABLE THIS
AFTERNOON. SO WILL CONTINUE THE HEAT ADVISORY FOR NOW.
UPDATE ISSUED AT 1013 AM CDT FRI SEP 6 2013
IMPULSE MOVING THROUGH UPPER LEVEL RIDGE IS PRODUCING SCATTERED
THUNDERSTORMS OVER WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING.
ONCE CELL OVER BOWMAN COUNTY PRODUCED QUARTER TO GOLF BALL SIZED
HAIL. EXPECT SCATTERED CONVECTION TO HAVE A HARD TIME MAINTAINING
ITSELF AS IT MOVES INTO CENTRAL NORTH DAKOTA...SOUTH OF THE
INTERSTATE. FARTHER NORTH WHERE CAP IS NOT AS STRONG...WILL
MAINTAIN A CHANCE OF THUNDERSTORMS THROUGH THE AFTERNOON. UPDATE
THIS MORNING WAS MAINLY FOR CLOUDS AND POPS BASED ON CURRENT RADAR
AND SATELLITE DATA. CURRENT CLOUD COVER MAY INHIBIT HEATING OVER
CENTRAL NORTH DAKOTA. WILL TAKE A CLOSER LOOK AT TEMPERATURES LATE
MORNING. NO CHANGES AT THIS TIME TO CURRENT HEAT ADVISORY.
UPDATE ISSUED AT 643 AM CDT FRI SEP 6 2013
SCATTERED THUNDERSTORMS CONTINUE TO ROTATE INTO WESTERN NORTH
DAKOTA AHEAD OF A SHORTWAVE. THE CURRENT FORECAST HAS THIS
SCENARIO HANDLED QUITE WELL...IN SPITE OF POOR MODEL GUIDANCE.
OTHERWISE...ONLY NEEDED TO ADJUST THE HOURLY SENSIBLE WEATHER
GRIDS BASED ON CURRENT OBS/TRENDS. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 535 AM CDT FRI SEP 6 2013
MID LEVEL ENERGY ROTATING AROUND THE RIDGE AXIS GENERATING AN
EXTENSIVE AREA OF SHOWERS/SCATTERED THUNDERSTORMS OVER EASTERN
MONTANA...MOVING EAST INTO WESTERN NORTH DAKOTA. MODELS EARLIER
FAILED TO CAPTURE THE TRUE EXTENT OF THE WAVE...WHICH IS NOW
BECOMING MORE EVIDENT AS PRECIPITATION MOVES INTO WESTERN NORTH
DAKOTA. UPDATED FORECAST TO INCREASE POPS THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CDT FRI SEP 6 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE HEAT AND
HUMIDITY THIS AFTERNOON...ALONG WITH CHANCES FOR THUNDERSTORMS
THROUGH THE PERIOD.
CURRENTLY...UPPER LEVEL HIGH PRESSURE CENTERED OVER EASTERN
COLORADO WITH THE RIDGE AXIS EXTENDING NORTH THROUGH THE NORTHERN
HIGH PLAINS INTO SOUTHERN ALBERTA. DEEP UPPER LEVEL LOW CENTERED
OVER OREGON EARLY THIS MORNING. WATER VAPOR AND NEAR TERM MODEL
GUIDANCE DEPICT AN EMBEDDED S/WV ROTATING NORTHEAST AROUND/THROUGH
THE RIDGE AXIS OVER CENTRAL/NORTHEASTERN MONTANA. THIS FEATURE IS
FORECAST TO TURN MORE EASTERLY ACROSS SOUTHERN SASKATCHEWAN THIS
MORNING...THEN MOVE ALONG THE INTERNATIONAL BORDER THIS AFTERNOON.
ASSOCIATED SHOWERS AND THUNDERSTORMS NOW OVER NORTHEASTERN MONTANA
ARE PROJECTED TO MOVE INTO NORTHWEST NORTH DAKOTA BETWEEN 09-11Z.
WILL ALSO NEED TO KEEP AN EYE ON ANOTHER AREA OF MORE ROBUST
THUNDERSTORMS SOUTH OF GLASGOW NEAR THE CENTER OF A SFC LOW. THEIR
CURRENT TRACK WOULD MISS ND...BUT WILL NEED TO MONITOR FOR
ADDITIONAL DEVELOPMENT OR CHANGE IN DIRECTION.
SURFACE LOW PRESSURE LINGERS OVER EASTERN MONTANA
TODAY...RESULTING IN STRONG WAA ACROSS THE DAKOTAS ALONG WITH
INCREASING LOW LEVEL MOISTURE. 12Z MODELS PROJECT 925MB
TEMPERATURES OVER 34C ACROSS MY SOUTHWEST CORNER...AND THE 32C
ISOTHERM EXTENDING TO JUST SOUTH OF HIGHWAY 2 AND AS FAR EAST AS
THE JAMES RIVER VALLEY. BASED ON YESTERDAYS TEMPERATURES...THE
925MB TEMPS DEPICTED WILL SUPPORT MID/UPPER 90S ACROSS ALL OF
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA. COOLER NORTH ALONG TO
NORTH OF HIGHWAY 2 WHERE THE WA WILL NOT BE AS STRONG AND SKIES
ARE EXPECTED TO BE CLOUDIER. MID/UPPER 90S COUPLED WITH SFC
DEWPOINTS IN THE LOW TO MID 60S (POTENTIALLY UPPER 60S) WILL
RESULT IN WIDESPREAD HEAT INDEX VALUES BETWEEN 95-100F. WHILE ONLY
A FEW AREAS ACTUALLY REACH OR EXCEED 100F...OPTED TO ISSUE A HEAT
ADVISORY FOR TODAY ACROSS THE SOUTHERN TWO-THIRDS OF THE CWA DUE
TO THE LATENESS OF THE HEAT...YOUTH ACTIVITIES IN FULL SWING...AND
SEVERAL MAJOR OUTDOOR EVENTS TAKING PLACE TODAY.
PRECIPITATION/THUNDERSTORM CHANCES WILL BE CONFINED TO MY
NORTHWEST AND NORTH CENTRAL THIS MORNING THROUGH 20Z THIS
AFTERNOON NEAR THE BETTER FORCING ASSOCIATED WITH THE EMBEDDED
WAVE.
STILL UNSURE WHAT WILL MATERIALIZE IN THE MID TO LATE AFTERNOON
HOURS. THE ABOVE MENTIONED S/WV WILL HAVE MOVED INTO NORTHEASTERN
NORTH DAKOTA BY THE LATE AFTERNOON...WITH NO OTHER DISTINGUISHABLE
TRIGGER INDICATED BY THE MOST RECENT GUIDANCE. HIGH RESOLUTION 4KM
WRF AND THE NCEP NESTED NAM SEEM TO BE PICKING UP ON THIS AND ARE
MAINLY DRY THROUGH EARLY EVENING. THUS KEPT POPS AT SLIGHT CHANCE
UNTIL LATER THIS EVENING WHEN PERHAPS WE WILL SEE A BIT BETTER
LOW LEVEL FORCING WITH INCREASING OVERRUNNING FLOW AHEAD OF THE
SFC LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 409 AM CDT FRI SEP 6 2013
AN ACTIVE WEATHER PATTERN IS STILL FORECAST FOR THE WEEKEND. A
DRYING TREND IS EXPECTED MONDAY THROUGH THE REMAINDER OF THE PERIOD.
AN UPPER LEVEL LOW CURRENTLY OVER THE PACIFIC NORTHWEST IS PROGGED
TO GRADUALLY TRAVERSE THE NORTHERN ROCKIES SATURDAY THROUGH SUNDAY.
INCREASING MOISTURE COMBINED WITH SHORTWAVES EMANATING FROM THE LOW
WILL LEAD TO INCREASING PRECIP CHANCES FROM WEST TO EAST OVER
WESTERN AND CENTRAL NORTH DAKOTA. FOR NOW IT STILL LOOKS LIKE THE
GREATEST SEVERE WEATHER POTENTIAL WILL BE FAVORED ACROSS
SOUTHWESTERN AND SOUTH CENTRAL NORTH DAKOTA LATE SUNDAY
AFTERNOON/EVENING. GIVEN THE POSITION OF THE UPPER LOW...DEEP LAYER
SHEAR IS PROGGED TO RANGE FROM 30-40 KNOTS ACROSS THE ENTIRE STATE.
HOWEVER...INSTABILITY PARAMETERS ARE MAXIMIZED (MUCAPE VALUES
GREATER THAN 1000 J/KG) SOUTHWEST OF THE MISSOURI RIVER. WILL
CONTINUE TO HIGHLIGHT THIS POSSIBILITY IN THE HWO.
PRECIP CHANCES ARE FORECAST TO DECREASE THROUGH THE DAY MONDAY AS
THE UPPER LEVEL TROUGH AXIS PIVOTS ACROSS THE STATE. THE DRYING
TREND SHOULD CONTINUE THROUGH THE END OF THE PERIOD AS UPPER LEVEL
RIDGING BUILDS OVER THE NORTHERN ROCKIES. TEMPERATURES ARE FORECAST
TO REMAIN ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1234 PM CDT FRI SEP 6 2013
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. ISOLATED SHOWERS
WILL MOVE ACROSS CENTRAL NORTH DAKOTA THIS AFTERNOON.
PRECIPITATION CHANCE INCREASE ON SATURDAY WITH SURFACE FLOW
TURNING NORTHEAST TO EAST ACROSS THE AREA. FOR NOW KEPT MID AND
HIGH LEVEL VFR CLOUDINESS WITH VCSH...AS PRECIPITATION CHANCES
WILL BE BETTER BEYOND THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NDZ017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...TWH
SHORT TERM...NH
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1241 PM CDT FRI SEP 6 2013
.DISCUSSION...
18Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
KCLL/KUTS/KCXO...MAINLY KEEP CONVECTION OUT OF TAFS EXCEPT FOR
CXO. THINK THERE IS A SMALL CHANCE A FEW SHRA/TSRA COULD DEVELOP
BUT NOT ENOUGH CONFIDENCE TO PUT IN TAFS. CXO JUST FAR ENOUGH
SOUTH IN BETTER MOISTURE TO NEED VCTS THIS AFTERNOON. OTHERWISE
EXPECT VFR CIGS. KCXO MAY HAVE 3-4SM VSBY IN THE MORNING FOR MVFR
CIGS. TOMORROW LOOKS LIKE A REPEAT OF TODAY BUT COULD HAVE MORE
HIGH CLOUDS WITH SHORT WAVE TROUGH COMING INTO NE TX.
KIAH/KHOU/KSGR...CONVECTION WORKING UP FROM THE SE SHOULD AFFECT
THESE TERMINALS THIS AFTERNOON WITH RE-DEVELOPMENT ALONG SEA
BREEZE/OUTFLOW BOUNDARIES. WILL KEEP VCTS UNTIL EARLY EVENING AS
ACTIVITY SHOULD BE COMING TO AN END PER LATEST HRRR MODEL RUNS.
SHOULD HAVE VFR CIGS OVERNIGHT AND LOOKS LIKE TOMORROW WILL BE
SIMILAR TO TODAY.
KLBX/KGLS...CONVECTION HAS MOVED BY SO NOT EXPECT MUCH IN THE WAY
OF SHRA/TSRA AFTER 19/20Z TODAY. MAY GET SOME 3-4SM VSBY AT KLBX
IN THE MORNING HOURS WITH WET GROUNDS DUE TO RAIN AND GOOD
RADIATIONAL COOLING OVERNIGHT. PLENTY OF MOISTURE STILL LINGERING
AROUND SO WILL GO WITH VCSH IN THE MORNING HOURS WITH CONVECTION
MOVING OFF THE GULF AGAIN.
39
&&
.PREV DISCUSSION... /ISSUED 1109 AM CDT FRI SEP 6 2013/
DISCUSSION...
SO FAR...THINGS LOOKING A LOT LIKE YESTERDAY. RADAR INDICATING A
DECENT AMOUNT OF COVERAGE OVER THE COASTAL WATERS AND HINTS THAT
ACTIVITY WILL BE INCREASING OVER INLAND AREAS SHORTLY. SOUNDINGS
SUPPORTIVE OF SCT TSRA TODAY AND PERHAPS SLIGHTLY STRONGER STEER-
ING CURRENTS THAN FROM DAYS PAST. THIS SHOULD LESSEN THE CHANCES
OF LOCALLY HEAVY RAINS THROUGH THIS EVENING. THE CURRENT FCST OF
HIGHEST POPS CLOSER TO THE COAST LOOKS GOOD. NO MAJOR CHANGES IN
THE OFFING ATTM. 41
PREV DISCUSSION... /ISSUED 420 AM CDT FRI SEP 6 2013/
00Z SOUNDINGS SHOW PW VALUES NEAR 2.3 INCHES AT KLCH AND 2.0
INCHES NEAR KCRP. IT IS CONSIDERABLY DRIER TO THE NORTH WITH KSHV
REPORTING A PW OF 1.14 INCHES. 850 MB MOISTURE STILL LOOKS RATHER
PLENTIFUL WITH 850 MB DEW PTS AROUND 14 C OVER SE TX. 700 MB
MOISTURE ALSO LOOKS RATHER STOUT WITH WITH DEW PT VALUES AROUND 8
C. THERE ALSO LOOKS TO BE A WEAK 700 MB TROUGH AXIS THAT LIES
NORTH TO SOUTH ACROSS EAST TEXAS. BOTH THE GFS AND ECMWF SHOW A
VORT LOBE ROTATING ACROSS SE TX THIS AFTERNOON FROM THE NORTH.
FEEL THE COMBINATION OF THE VORT...DAYTIME HEATING...WEAK 700 MB
BOUNDARY AND DEEP MOISTURE SHOULD ALLOW FOR A DECENT CHANCE OF
SHRA/TSRA THIS AFTERNOON.
PW VALUES LOOK A BIT LOWER ON SATURDAY BUT A STRONG VORT LOBE
WILL ROTATE AROUND THE UPPER RIDGE AND WILL ONCE AGAIN SERVE AS A
CATALYST FOR SHRA/TSRA ON SATURDAY. WILL MAINTAIN CHANCE POPS ON
SATURDAY. PW VALUES FALL FURTHER SUNDAY AND MONDAY BUT THE
POSITION OF THE UPPER RIDGE LOOKS FAR ENOUGH NORTH TO LIMIT
SUBSIDENCE. DAYTIME HEATING SHOULD AGAIN SERVE AS THE CATALYST FOR
A SLIGHT CHANCE OF SHRA/TSRA BOTH DAYS.
TUES-WEDS LOOK RATHER INTERESTING. A STRONG EASTERLY WAVE WILL
APPROACH THE TEXAS COAST EARLY TUESDAY. THE UPPER RIDGE
STRENGTHENS A BIT AND THE POSITION OF THE RIDGE WILL DETERMINE WHO
GETS HEAVY RAIN AND WHO STAYS DRY. THE GFS IS WEAKER AND FURTHER
NORTHEAST WITH THE RIDGE WHILE THE ECMWF IS STRONGER AND FURTHER
SOUTHWEST. PW VALUES CLIMB TO 2.2 INCHES AND FCST SOUNDINGS LOOK
SATURATED. MOISTURE SHOULD CONTINUE TO STREAM INTO SE TX ON THE
BACK SIDE OF THE UPPER RIDGE AND GIVE SE SE TX A GOOD CHANCE OF
RAIN TUES INTO WED. IF THE GFS IS CORRECT WITH THE POSITION OF THE
UPPER RIDGE...SE TX WILL HAVE HIGH RAIN CHANCES BOTH TUES/WED
BEFORE DRIER AIR WORKS INTO THE REGION ON THURSDAY. WITH THE HIGH
MOISTURE CONTENT AND POTENTIAL FOR TRAINING CELLS...THE POTENTIAL
FOR HEAVY RAIN ALSO EXISTS. STILL A GREAT DEAL OF UNCERTAINTY
REGARDING THE POSITION OF THE UPPER RIDGE SO COMPROMISED BETWEEN
THE WETTER GFS AND DRIER ECMWF FOR NOW AND WILL AWAIT BETTER MODEL
CONSENSUS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 98 75 98 75 98 / 20 20 20 10 20
HOUSTON (IAH) 96 75 95 75 96 / 30 30 30 10 20
GALVESTON (GLS) 89 80 89 80 89 / 30 30 30 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...41
AVIATION/MARINE...39