FXUS64 KHUN 140548 AFDHUN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HUNTSVILLE AL 1148 PM CST SAT DEC 13 2014 .UPDATE... FOR 06Z TAFS && .DISCUSSION... /ISSUED 957 PM CST SAT DEC 13 2014/ THE PRIMARY SHORT TERM FORECAST CONCERN CONTINUES TO BE A BROAD DECK OF STRATUS CLOUDS -- WHICH CURRENTLY ENCOMPASSES THE MAJORITY OF THE FORECAST AREA WEST OF INTERSTATE 65. THE STRATUS IS ESSENTIALLY DEVELOPING IN A REGION OF SHALLOW ISENTROPIC ASCENT BETWEEN THE 280-290K SURFACES...WHICH IS MOST PRONOUNCED ALONG AN AXIS EXTENDING FROM SOUTHERN ILLINOIS/INDIANA SOUTHWARD INTO WESTERN TENNESSEE. SOUTHWARD ADVECTION OF THE CLOUD DECK INTO NORTHERN ALABAMA IS BEING MAINTAINED BY NORTHERLY FLOW OF 10-20 KNOTS WITHIN THE CLOUD BEARING LAYER...AND THUS EXPECT THE STRATUS DECK TO REMAIN IN PLACE OVER THE WESTERN ZONES THROUGHOUT THE NIGHT. ACROSS THE EAST -- WHERE SKIES ARE CURRENTLY CLEAR AND SHOULD REMAIN CLEAR OVERNIGHT -- FOG HAS RECENTLY DEVELOPED. WITH THE LOW-LEVELS COOLING MORE EFFICIENTLY ACROSS NORTHEAST ALABAMA...TEMPERATURES HAVE ALREADY APPROACHED OR FALLEN SLIGHTLY BELOW FREEZING AND THE DEVELOPING FOG WILL TAKE THE FORM OF FREEZING FOG. SKY COVER GRIDS HAVE BEEN ADJUSTED TO REFLECT REASONING MENTIONED ABOVE...AND PATCHY FREEZING FOG HAS BEEN ADDED TO THE NORTHEAST ALABAMA ZONES. MINIMUM TEMPERATURES WERE ADJUSTED UPWARD BY 1-3 DEGREES BENEATH CLOUD COVER IN THE NORTHWEST...AND REDUCED BY 1-3 DEGREES FOR REMAINDER OF THE REGION. 70/DD && .AVIATION... FOR 06Z TAFS...NO CHANGES TO PREVIOUS AVIATION FORECAST REASONING. MVFR CONDS IN THICK STRATUS WILL PREVAIL AT BOTH MSL/HSV THRU THE VALID TAF PERIOD -- WITH LITTLE HOPE FOR IMPROVEMENT UNTIL PERHAPS SUNDAY EVENING. CIGS WILL PREDOMINATELY BE IN THE 2000-2500 FT RANGE...ALTHOUGH A BRIEF PERIOD OF CIGS AS LOW AS 1500 FT WILL BE PSBL AROUND 14/12Z. IF SKIES MANAGE TO CLEAR SUNDAY EVENING... LGT/VRBL FLOW WILL PROMOTE DEVELOPMENT OF PATCHY BR/FG...BUT THIS WOULD MOST LIKELY OCCUR AT HSV. SFC WINDS WILL REMAIN 3-7 KTS FROM THE NE AT HSV...BUT SHOULD BE LGT/VRBL THRU THE PERIOD AT MSL. 70/DD && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WEATHER.GOV/HUNTSVILLE.
Posted on: Sun, 14 Dec 2014 05:49:17 +0000
Recently Viewed Topics
© 2015