480 FXUS63 KLSX 301758 AFDLSX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ST LOUIS MO 1158 AM CST Thu Jan 30 2014 .UPDATE: Issued at 1141 AM CST Thu Jan 30 2014 Going fcst looks on track. Will be issuing an update shortly. Adjusted parameters for current trends. Didn't do much with temp or winds. Winds may not be quite as strong early this aftn as currently fcst...but difference is minor. Was briefed that a wind advy might be needed if winds were a little stronger than fcst...this appears unnecessary attm. Also...temps may need to be lowered a few degrees...but will wait a couple of hrs to see what happens. Light precip is currently moving thru NE MO and current chance POPs covers the threat nicely. 2% && .SHORT TERM: (Through Late This Afternoon) Issued at 450 AM CST Thu Jan 30 2014 Active weather pattern over the next week. For today, dealing with a couple of items. Will see decent mixing today, so with winds aloft 50kts+ they will be brought down to surface ahead of next cold front. Wind gusts will be close to advisory criteria but will hold off issuing one for now. Then dealing with low rh values, strong winds and low fuel moisture, so have issued a Red Flag Warning for portions of the forecast area, mainly along and south of I70 from 18z to 23z today. With these gusty south to southwest winds, temperatures to moderate quite a bit with highs in the 40s. Could even see near 50 over central MO. Cold front to move into northern portions of forecast area late this afternoon. Moisture is limited initially with this front, so just have low chance pops in the far north with rain mixed with snow at times. Byrd .LONG TERM: (Tonight through Wednesday) Issued at 450 AM CST Thu Jan 30 2014 Cold front continues to slowly slide south and stalling over southern portions of forecast area tonight. Precipitation to taper off across the north this evening before next shortwave approaches towards daybreak on Friday. Most of precipitation will be in the form of snow with some rain mixed in where temperatures are a bit above freezing. Lows will range from the mid teens far north to near 30 far south. On Friday, things become interesting as a warm front develops south of I70. Will see temperatures aloft slowly warm up above freezing for portions of the area, but surface temperatures will be tricky. Freezing line will be along I70 corridor. So as precipitation falls through the column, will see some melting, thus freezing rain/rain, mixed with some sleet and snow possible. Further north it will be all snow. The precipitation will pickup in intensity Friday night and continue into Saturday. Snowfall amounts of two to five inches can be expected over central/northeast MO as well as west central IL. Further south will see a mix of rain/freezing rain/sleet and snow. At this time, less than two tenths of an inch of ice accumulation is possible in an area from Jefferson City to Vandalia IL. Then could see some light snowfall accumulations in this area as well. Southeast MO, far southern IL should see mostly rain with some sleet and snow mixed in at times. Highs Friday will be in the low 20s far north to near 40 far south with lows Friday night in the mid teens to mid 30s. Highs on Saturday will range from the mid 20s to mid 40s. System to exit region by Saturday night as surface ridge builds in and colder air filters in. Will see dry conditions til Monday night as next weather system moves in. There is still significant uncertainty with this system. Medium range models continue to have trouble resolving timing and track of the storm with the GFS being faster than the ECMWF. Either way it looks like there's good potential for accumulating snow or possibly sleet south of the I-70 corridor Tuesday into Tuesday night. Byrd && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1141 AM CST Thu Jan 30 2014 VFR fcst with biggest concern S/SSW winds this aftn. A tight pressure gradient exist in advance of a cold front that extends from NE KS thru cntrl IA. Winds will continue thru at least mid aftn before a minor wind shift occurs that should decrease speeds a little. Winds become light overnight as the cold front passes thru and then eventually turn NErly by Friday morning. Current precip across NE MO is expected to continue east thru the aftn and should exit the terminal by 00Z. Specifics for KSTL: Gusty S/SW winds will continue thru the aftn and then become light this evening as a cold front approaches. The front should pass thru around 6Z. Winds will eventually become NErly by Friday morning. There is the threat of some light precip Friday morning...but no confident enough in timing or coverage to include attm. CIGs should remain aoa 5kft thru 12Z Friday. 2% && .FIRE WEATHER: Issued at 358 PM CST Wed Jan 29 2014 Relative humidity values will once again drop below that critical fire weather threshold of 25 percent for areas along and south of I-70. Also, it will be warmer today with southerly winds increasing above 15 mph with gusts to 40 mph. 10 hour dead fuel moisture values remain near critical values. The combination of all these factors could lead to a four or five hour period of red flag conditions this afternoon. So a Red Flag Warning has been issued for portions of the southern CWA for this afternoon. BYRD && .LSX WATCHES/WARNINGS/ADVISORIES: MO...RED FLAG WARNING until 5 PM CST this afternoon FOR Boone MO- Callaway MO-Cole MO-Crawford MO-Dent MO-Franklin MO- Gasconade MO-Iron MO-Jefferson MO-Madison MO-Moniteau MO- Montgomery MO-Osage MO-Reynolds MO-St. Charles MO-St. Francois MO-St. Louis City MO-St. Louis MO-Ste. Genevieve MO-Warren MO-Washington MO. IL...RED FLAG WARNING until 5 PM CST this afternoon FOR Clinton IL- Madison IL-Marion IL-Monroe IL-Randolph IL-St. Clair IL- Washington IL. && $$ WFO LSX