Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 291505
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1105 AM EDT WED JUL 29 2015

.UPDATE...
ISSUED AT 1054 AM EDT WED JUL 29 2015

ONE LONE RAIN SHOWER JUST NORTH OF BELLAIRE IN ANTRIM COUNTY.
STILL BELIEVE THAT THERE IS SOME INCREASED CHANCE FOR RAIN SHOWERS
AND PERHAPS A FEW THUNDERSTORMS ACROSS NE LOWER THIS AFTERNOON.
HEATING IS UNDERWAY WITH SFC BASED TEMPS ALREADY CLIMBING INTO
THE MIDDLE 80S WITH SFC TD`S AVERAGING IN THE MIDDLE 60S...ON THE
WAY TO CAPE VALUES DISCUSSED IN PREVIOUS UPDATE.

UPDATE ISSUED AT 805 AM EDT WED JUL 29 2015

IMPACT WEATHER: SCATTERED THUNDERSTORMS DEVELOPING THROUGH THE DAY.

SYNOPTIC PATTERN AND OBSERVATIONS:

MORNING ANALYSIS...LOW PRESSURE WAS PUSHING THROUGH WESTERN ONTARIO
WHILE DRAGGING A COLD FRONT ACROSS CENTRAL LAKE SUPERIOR...EASTERN
WISCONSIN AND ILLINOIS. SFC OBS...UPPER AIR AND HI-RES THETA-E
ANALYSIS SHOWING A WARM FRONT OUT AHEAD OF THE COLD FRONT...DRAPED
FROM CENTRAL LAKE MICHIGAN TO NRN INDIANA. THIS LEAVES A RATHER
NARROW "WARM SECTOR" THAT WAS PROGRESSING INTO THE REGION...WIDEST
THOUGH ACROSS THE SRN CWA. SCATTERED SHOWERS WERE SEEN ACROSS SRN WI
AND SRN LAKE MICHIGAN...IN THE WARM SECTOR...FORCED BY SOME UPPER
DIVERGENCE IN RIGHT ENTRANCE REGION OF 100+KT JET OVER MN. ALSO IN
PLAY...WEAK VORTICITY MAXIMA IN THE SRN END OF THE BETTER SW FLOW
ALOFT ACROSS THIS REGION. THERE WAS NOTHING ON THE FRONT NORTH OF
THIS FORCING. LAPSE RATES ALOFT WERE NOT TOO GOOD AT 5.0 C/KM AND THE
RESULTING CAPE WAS MINIMAL TO NONE AT THE MOMENT. WIND FIELDS ARE
ALSO PATHETIC RIGHT NOW...BUT STRONGER WINDS AND RESULTANT 0-6KM
BULK SHEAR OF 25-30KTS WAS ACROSS SRN WISCONSIN...GETTING A LITTLE
BETTER.

THROUGH THE DAY...AFOREMENTIONED WARM/COLD FRONTS LIFT INTO NRN
MICHIGAN..WITH WIDEST WARM SECTOR...BETTER PVA/VORTICITY AND
POSSIBLE WEAK UPPER DIVERGENCE (ALTHOUGH WE ARE REALLY IN A POOR
POSITION OF THE UPPER JET) TO SPREAD ACROSS THE SRN CWA. LAPSE RATES
IMPROVE LITTLE...MAXING OUT AT 5.5 C/KM...WHILE THE FRONT MAKES IT
TO NE LOWER EARLY TO MID AFTERNOON. THE SITUATION IS NOW PLAYING OUT
FOR WARMING/DESTABILIZATION THROUGH THE DAY TO DEVELOP SHOWERS AND
SCATTERED THUNDERSTORMS ALONG THE FRONT. THE MOST INSTABILITY WE
SEEM TO BE ABLE TO GENERATE WILL BE SOMEWHERE BETWEEN 200 J/KG IN
EASTERN UPPER...TO AS MUCH AS 700-800 J/KG SOUTH. THIS IS MORE THAN
LIKELY NOT GOING TO RESULT IN ANY CHANCE OF ORGANIZED STORMS/SEVERE
WEATHER....EVEN WITH INCREASING WINDS/0-6KM BULK SHEAR THROUGH THE
DAY.

DO BELIEVE THAT SHOWERS WILL SLOWLY INCREASE THROUGH THE MORNING
WITH THE CHANCE OF THUNDERSTORMS INCREASING ALONG/AHEAD OF THE FRONT
THROUGH THE LATE MORNING/EARLY AFTERNOON.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 331 AM EDT WED JUL 29 2015

PERSISTENT HIGH PRESSURE HAS SHIFTED EAST OF MICHIGAN EARLY THIS
MORNING AS A COLD FRONT APPROACHES FROM THE WEST. MID AND HIGH
CLOUDS HAVE BEGUN TO INCREASE ALONG THE NE PERIPHERY OF THE
CONVECTIVE CLOUD SHIELD GENERATED FROM THE MCS CURRENTLY IMPACTING
IOWA...NRN MISSOURI AND NRN ILLINOIS. THIS CONVECTION IS FUELED BY A
STRONG INSTABILITY AXIS (CAPES OF AROUND 3000 JOULES) AND 850 MB
THETA E RIDGING PUNCHING THRU THE MISSISSIPPI VALLEY ATTM. FURTHER
NORTH...OUR UPSTREAM RADARS SHOW A FEW SHOWERS AND EMBEDDED WEAK
STORMS TRYING TO DEVELOP JUST EAST OF THE ARROWHEAD OF MINNESOTA
OVER WRN LAKE SUPERIOR JUST AHEAD OF THE APPROACHING COLD FRONT.
CONVECTION IS STRUGGLING DUE TO WEAK INSTABILITY (500 JOULES OR
LESS) AND VERY LIMITED MOISTURE.

LATEST NAM12...RAP13 AND HRRR ALL SUGGEST THE FOCUS FOR MEANINGFUL
CONVECTIVE DEVELOPMENT WILL STAY SOUTH OF OUR CWA THRU TODAY WHERE
STRONGER INSTABILITY AND MUCH BETTER MOISTURE WILL RESIDE. NORTHERN
MICHIGAN IS ONCE AGAIN LOOKING AT THE PROSPECT THAT THE MAJORITY OF
OUR CWA MAY MISS OUT ON AN OPPORTUNITY FOR SOME MUCH NEEDED RAIN
TODAY. STILL...CHANCE POPS WILL REMAIN IN ORDER THRU THE DAY...WITH
THE EXPECTATION THAT A NARROW LINE OF SCATTERED SHOWERS WITH SOME
EMBEDDED THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD
FRONT. WILL MAKE SOME MINOR TIMING ADJUSTMENTS TO THIS BAND OF
PRECIP AS IT SLOWLY MOVES THRU OUR CWA TODAY...BUT WILL CERTAINLY
KEEP POPS IN THE CHANCE CATEGORY. NO REAL CHANCE FOR STRONG TO
SEVERE STORMS GIVEN LIMITED INSTABILITY AND MOISTURE AND
UNIMPRESSIVE WIND FIELDS AHEAD OF THE FRONT.

EXPECT ANOTHER VERY WARM DAY FOR NORTHERN MICHIGAN...BUT NOT AS WARM
AS IT HAS BEEN THE PAST FEW DAYS. HIGH TEMPS WILL WARM WELL INTO THE
80S...BUT SHOULD REFRAIN FROM REACHING INTO THE 90S. OVERNIGHT LOWS
WILL COOL BACK INTO THE 60S.

&&

.SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT)
ISSUED AT 331 AM EDT WED JUL 29 2015

(7/30)THURSDAY...WITH THE FRONTAL PASSAGE TODAY, THE TEMPERATURES
FALL BACK TO NORMAL FOR THURSDAY. THERE ARE TWO CONCERNS FOR THE DAY
AND INTO THE NIGHT. 1) CLOUD COVER, ESPECIALLY NEAR ANJ. THE 850 MB
RH IS AROUND 90%, AND WITH THE 850 MB TEMPERATURES NEAR +10C, NEAR E
UPPER, IT COULD BE CLOUDIER. WHICH LEADS TO 2) TEMPERATURES COULD
END UP COOLER IF THERE ARE MORE CLOUDS IN E UPPER AND EVEN PARTS OF
THE N LOWER IF THE CLOUDS MAKE IT DOWN FAR ENOUGH SOUTH, BUT THAT
SEEMS ONLY TO ABOUT M-32 AT THE MOST.

SOUTH OF M-32, HOWEVER, THERE IS A DIFFERENT CONCERN, FIRE WEATHER.
WILL EXPECT THAT THE HIGH TEMPERATURES WILL REMAIN OVER 75F (CIPS
ANALOG GUIDANCE SHOWS 70% AT THE TEMPERATURES>75F). WINDS WILL BE
AROUND 15MPH AT THE 20FT LEVEL (SUSTAINED), WITH THE RH AROUND 30-
35%. AND WITH THE EXTENDED DRY PERIOD, WILL BE GOING WITH THE
ELEVATED FIRE DANGER.

(7/31)FRIDAY...THE DISCUSSION FOR THURSDAY COULD VERY WELL FIT FOR
FRIDAY AS WELL, EXCEPT THAT THERE IS A WEAK SFC LOW TRYING TO MOVE
INTO THE REGION AS THE 500 MB LOW SINKS A LITTLE MORE SOUTH AND
BEGINS TO COOL THINGS DOWN A BIT. AGAIN THE COOLEST, PROBABLY
CLOUDIEST AREA WILL BE NORTH OF M-32, WITH THE SOO DROPPING INTO THE
LOWER 70S FOR HIGHS POSSIBLY. LOOKS LIKE WE ARE STILL AROUND 80S
SOUTH OF M-32, AND WINDS WILL BE AGAIN BE CLOSE TO 15 MPH AT 20FT,
SO THERE IS AN ELEVATED FIRE DANGER RISK, ALTHOUGH THE RH MAY NOT BE
AS BAD THURSDAY. HOWEVER, IT WILL STILL BE AN ISSUE.

&&

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 331 AM EDT WED JUL 29 2015

WITH THE 500 MB LOW JUST NORTH OF JAMES BAY, WE GO BACK TO THE
PATTERN THAT WE`VE HAD OVER N MICHIGAN THE LAST 2 YEARS WITH
COOLER THAN NORMAL TEMPERATURES AND POSSIBLY SHOWERY CONDITIONS,
BUT NOTHING APPRECIABLE, AT LEAST FOR THE TIME BEING. CIPS ANALOGS
FALL RIGHT IN LINE WITH THE MEX NUMBERS AS WELL AS THE ECMWF
IDEAS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY)
ISSUED AT 650 AM EDT WED JUL 29 2015

OVERALL CONDITIONS WILL REMAIN VFR AT ALL NRN LWR MICHIGAN TAF
SITES THRU WEDNESDAY NIGHT. A COLD FRONT WILL SWEEP THRU THE
REGION TODAY. LIMITED MOISTURE AND ONLY WEAK INSTABILITY ALONG AND
AHEAD OF THE FRONT WILL RESTRICT POPS TO ONLY CHANCE. EXPECT A
BAND OF SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS WILL
SLOWLY PUSH FROM WEST TO EAST THRU NRN LWR MICHIGAN THROUGHOUT
THE DAY. WILL CONTINUE TO HANDLE WITH VCSH IN THE TAFS FOR NOW.
SOUTH WINDS UNDER 10 KTS WILL SHIFT TO THE WEST IN THE WAKE OF THE
FRONT AND WILL INCREASE TO 10 TO 15 KTS...WITH A FEW HIGHER GUSTS
POSSIBLE.


&&

.MARINE...
ISSUED AT 1054 AM EDT WED JUL 29 2015

...BECOMING BREEZY THROUGH THE AFTERNOON...

A COLD FRONT IS CROSSING INTO NRN MICHIGAN LATE THIS MORNING WITH
DEEP DRY AIR AND GUSTY WESTERLY WINDS MAKING THEIR WAY EAST ACROSS
LAKE MICHIGAN. FEEL FAIRLY CONFIDENT IN THE DEVELOPMENT OF
ADVISORY LEVEL WINDS DEVELOPING OVER MOST OF THE NEARSHORE WATERS
THROUGH TONIGHT...AS SHALLOW COOLER AIR RESULTS IN NEAR NEUTRAL
STABILITY OVER THE LAKES. COULD BE DEALING WITH SOME CONTINUED
ADVISORY LEVEL GUSTS FOR LATER PERIODS...AS WINDS REMAIN WESTERLY.

LOOKING FOR SOME SCATTERED SHOWERS AND PERHAPS SOME THUNDERSTORMS
ALONG AND AHEAD OF THE COLD FRONT...FOR THE NE LOWER NEARSHORE
WATERS FOR THE EARLY AND MID AFTERNOON.



&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR LHZ345>347.

LM...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR LMZ323-341-342-
     344>346.

LS...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR LSZ322.

&&

$$

UPDATE...SMD
NEAR TERM...MLR
SHORT TERM...JSL
LONG TERM...JSL
AVIATION...MLR
MARINE...SMD


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