FXUS64 KHUN 060913
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
313 AM CST SUN DEC 6 2009
.SHORT TERM DISCUSSION (THROUGH TUESDAY NIGHT)...
HIGH LEVEL MOISTURE WILL INCREASE ACROSS THE REGION TODAY AHEAD OF
STRENGTHENING STORM SYSTEM OVER THE PACIFIC NORTHWEST/GREAT BASIN
REGION. ONE UPR WAVE FROM THIS SYSTEM WILL EJECT EAST ACROSS THE
CNTRL PLAINS TONIGHT. THIS WEAK LOW PRESSURE SYSTEM WILL BE
RESPONSIBLE FOR INCREASING THE CHANCE FOR LIGHT RAIN ACROSS THE
CENTRAL TENNESSEE VALLEY MONDAY.
OVER THE NEXT 24 HOURS HOWEVER...HIGH PRESSURE WILL BE IN CONTROL
RESULTING IN DRY/STABLE CONDITIONS. AIRMASS THAT BROUGHT THE COLDEST
TEMPS TO THE AREA SINCE EARLY MARCH THIS MORNING WILL GRADUALLY
MODERATE BUT TEMPS WILL STILL REMAIN 5-7F BELOW NORMAL TODAY.
MOISTURE WILL DEEPEN TONIGHT INTO MONDAY AS AFOREMENTIONED UPR WAVE
AND ACCOMPANYING WEAK FRONTAL BOUNDARY CROSS THE REGION. UPR JET
ENERGY COUPLED WITH FAVORABLE ISENTROPIC ASCENT/LOW LVL CONVG WILL
COME TOGETHER MONDAY...SUPPORTING THE CHANCE FOR RAIN. BUMPED POPS
UP TO "LIKELY" MONDAY HOWEVER LIMITED MOISTURE AND LACK OF
LARGE-SCALE FORCING WILL KEEP RAIN AMOUNTS RATHER LIGHT.
TUESDAY/TUESDAY NIGHT...MORE POTENT UPR LVL WAVE WILL EJECT OUT OF
THE FOUR CORNERS TUESDAY AND TRACK E/NE TOWARD THE OHIO VALLEY BY
12Z/WED. AS THIS OCCURS...LOW PRESSURE WILL RAPIDLY DEEPEN BETWEEN
THE SRN PLAINS AND THE GREAT LAKES. A SECONDARY LOW IS EXPECTED TO
DEVELOP ALONG THE TX GULF COAST AND TRACK NORTHEAST LATE MON NGT
INTO TUESDAY. THIS FEATURE WILL SUPPORT THE FIRST ROUND OF PRECIP
ACROSS NRN AL/SRN TN TUESDAY...WITH ANOTHER ROUND OF SHOWERS AND
PERHAPS AN ISOLATED THUNDERSTORM TUESDAY NIGHT WITH THE PASSAGE OF
THE SFC FRONT. A SIGNIFICANT AMOUNT OF WIND ENERGY WILL ACCOMPANY
THIS SYSTEM ALONG WITH DEEP SUB-TROPICAL MOISTURE. THE PRESENCE OF
LARGE-SCALE FORCING WILL SUPPORT THE POTENTIAL FOR HEAVY RAIN ACROSS
THE AREA TUES/TUES NGT. WITH THE EXCEPTION OF THE 00Z/06 NAM...
MODELS KEEP HIGHEST QPF JUST SOUTH/WEST OF THE AREA /OVER THE LWR MS
VLY/ WHERE BETTER FORCING AND MOISTURE WILL EXIST. AT THIS TIME...
FEEL TOTAL RAINFALL AMOUNTS OF 1 TO 2 INCHES WILL BE COMMON ACROSS
THE AREA TUES/TUES NGT. REGARDING THUNDERSTORM POTENTIAL WITH THIS
SYSTEM...INSTABILITY IS MARGINAL AT BEST BUT DEEP LYR SHEAR WILL
SUPPORT THE THREAT OF ISOLD WIND DAMAGE WITH ANY CONVECTION LATE
TUES AFTN/TUES NGT.
.LONG TERM (WEDNESDAY THROUGH SATURDAY)...
MEDIUM RANGE MODELS ARE IN PRETTY GOOD AGREEMENT SHOWING SYSTEM
DEPARTING THE REGION WEDNESDAY WITH DRIER/COOLER CONDITIONS EXPECTED
THROUGH THURSDAY. FAST-MOVING ZONAL/SOUTHWEST FLOW ACROSS THE AREA
WILL SEND A RELATIVELY WEAK DISTURBANCE ACROSS THE AREA LATE FRIDAY
INTO SATURDAY. MODELS DEVIATE QUICKLY ON TIMING/TRACK OF THIS SYSTEM
WITH THE 00Z/06 ECMWF SLOWER AND FARTHER SOUTH. GFS ENSEMBLE MEANS
TEND TO LEAN TOWARD THE EC SOLN SO WILL GO WITH THE SLIGHTLY SLOWER
SYSTEM...INCREASING RAIN CHANCES NEXT SATURDAY. BEHIND THE MID WEEK
SYSTEM...SLIGHTLY COOLER THAN NORMAL TEMPS WILL EXIST THROUGH THE
REMAINDER OF THE PERIOD. NADLER.83
&&
.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE 48 34 48 41 56 / 0 10 60 20 70
SHOALS 49 35 49 42 57 / 0 20 60 20 70
VINEMONT 47 34 49 42 57 / 0 10 60 20 70
FAYETTEVILLE 46 33 47 37 55 / 0 10 60 10 70
ALBERTVILLE 47 33 48 41 56 / 0 10 60 20 70
FORT PAYNE 48 28 50 39 55 / 0 0 60 20 70
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&
$$
DJN.83
