Monday Morning Forecast

Forecast issued by Michael Leach and Jason Holmes on 09/18/06 at 12:00:40 am CDT

Mobile, Alabama 5 Day Forecast
Today	Tuesday	Wednesday	Thursday	Friday
86°F	84°F	82°F	85°F	87°F
	72°F	59°F	61°F	68°F
SSW 7-14 mph	NW 7-14 mph	N 5-10 mph	SSE 5-10 mph	S 5-10 mph
80%	40%	0%	0%	30%

Mobile, Alabama 5 Day Detailed Forecast

Today... Mostly cloudy with rain and thunderstorms. High 86. Winds south-southwest 7-14 mph. Chance of rain is 80 percent. Tonight... Mostly cloudy with rain and thunderstorms. Low 72. Winds southwest 5-10 mph. Chance of rain is 70 percent. Tuesday... A chance of showers and thunderstorms, mainly during the morning. Otherwise, partly cloudy. High 84. Winds northwest 7-14 mph. Chance of rain is 40 percent. Tuesday Night... Mostly clear. Low 59. Winds north 5-10 mph. Wednesday... Mostly sunny. High 82. Winds north 5-10 mph. Wednesday Night... Mostly clear. Low 61. Winds east 4-8 mph. Thursday... Partly cloudy. High 85. Winds south-southeast 5-10 mph. Thursday Night... Partly cloudy with isolated showers and thunderstorms. Low 68. Winds south 4-8 mph. Chance of rain is 20 percent. Friday... Partly cloudy with scattered showers and thunderstorms. High 87. Winds south 5-10 mph. Chance of rain is 30 percent.

Technical Discussion

Synopsis: Currently, an area of high pressure is centered over North Carolina. The rotation around this high gave us a southerly wind on Sunday, bringing in higher moisture values across the area. Dewpoints climbed into the middle 70's across the region on Sunday, and continue to hold in the 70's early this Monday morning. The barometric pressure has continued to fall over the past 24 hours as the high pressure area has shifted off to our east, and a cold front is approaching the area from the northwest. 00z regional soundings indicate the WAA pattern across the area, with veering winds noted on the soundings. KLIX and KTLH soundings show PWAT values significantly higher than yesterday at this time (2.28" at KLIX and 2.13" at KTLH). Interpolated sounding for Mobile shows PWAT values of 2.27", CAPE of 1583 J/KG, and LI of -4.2. Also noted is the veering winds from just above the surface up to around 500 mb. Short Term (Monday through Wednesday): The main challenges in the short term involve rain chances and the potential for strong storms. A very moist airmass is expected to remain over the area until fropa. The NAM is indicating that PWAT values could approach 2.50" over the area Monday night. This could lead to some heavy rainfall amounts over the area Monday through Tuesday. As previous forecast alluded to, widespread flooding is not a concern at this time due to the progressive nature of the system, but some localized flooding could be possible with the heavier showers and thunderstorms. As far as the severe threat goes, it looks rather minimal at this time. With the expected cloud cover, significant destabilization is not expected. However, if we were to get some breaks in the cloud cover during the day tomorrow, the air may destabilize more than currently anticipated. Also, models do not predict too much instability over the area (although CAPE values from regional 00z soundings were a little higher than model initializations). NAM and GFS both show a LLJ of around 30 to maybe 35 kts. tomorrow through Tuesday morning. With that said, we may get a few strong wind gusts with storms, and a few gusts may approach severe limits in isolated storms. This will be mentioned in hazardous weather section. The cold front is expected to move across the area on Tuesday. The GFS is a little quicker than the NAM with fropa. The GFS indicates fropa around 15z Tuesday morning, while the NAM indicates fropa closer to 18z on Tuesday. This is not a major difference between models, and expect the front to pass through sometime Tuesday morning or early afternoon. Therefore, will have PoP's on Tuesday mainly for the morning hours, with decreasing chances by the afternoon. Tuesday night looks rather cool at this time, with MOS guidance indicating lows in the upper 50's to around 60 degrees. Did not go quite as low at the MAV and MET guidance, and kept lows around 60 for Tuesday night. Wednesday looks to be a nice day, with CAA aloft, and surface high pressure ridging taking control of the weather. Sunny skies and highs in the lower 80's with dewpoints in the 50's can be expected on Wednesday. The MET guidance actually indicates highs staying in the upper 70's for Wednesday. Long Term (Thursday through Friday): Return flow from the Gulf is expected beginning on Thursday. Winds are expected to shift to the east, and eventually to the south on Thursday, bringing in more Gulf moisture to the region. Dewpoints will be on the increase on Thursday, and will likely climb back into the mid 60's. Still going with no PoP's on Thursday as only an increase in clouds is expected during the day. Kept the slight chance PoP for Thursday night as moisture becomes more entrenched over the area. Another trough and cold front will approach the area on Friday. The GFS is showing this trough and associated closed upper level low a little farther south than the current system we are dealing with. This trough also looks rather amplified on the GFS. At this time, will be conservative, and only go with 30% PoP on Friday. This may need to be increased in future forecasts. The rain chances will likely stick around through at least Saturday, until another cold front passes through the area. ML/JH

Hazardous Weather

Short Term (Monday through Tuesday afternoon): A strong cold front will approach the area from the northwest through Tuesday. Some of the thunderstorms may be strong with only isolated severe weather possible. The main threat from any severe storm would be damaging winds. Other storms may produce torrential rainfall that may cause localized flooding of low-lying or poor drainage areas along with gusty winds and frequent lightning strikes. The highest potential for strong to severe thunderstorms will primarily be from Monday afternoon through early Tuesday morning. JH/ML Long Term (Tuesday evening through Friday): No hazardous weather is expected. JH/ML

Astronomical and Climatological Data
Moon Phase Crescent Waning Sunrise 6:38 AM Sunset 6:54 PM	09/18/06 Normal High Record High Normal Low Record Low Temperature 86°F 96°F (1925) 67°F 54°F (1981) September Normal Wettest Driest Precipitation 6.01 in. 24.12 in. (1998) 0.47 in. (1923)