Monday, November 17, 2014

Hard Freeze warning

Synopsis/Overview: A strong cold front will sweep south through West Central and Southwest Florida during this afternoon and tonight and will move south of the state on Tuesday. Ample moisture, instability, and low level convergence along and ahead of this front will support numerous showers and scattered thunderstorms across the region today and continuing into tonight as the front moves through. Warnings/Watches/Advisories: (See www.weather.gov/tampa for more details)  Hard Freeze Watch in effect for Levy and Citrus Counties from late Tuesday night through early Wednesday morning.  Freeze Watch in effect for Hernando and Sumter Counties from late Tuesday night through early Wednesday morning. Impact 1: Severe Storms Increasing wind fields ahead of a strong cold front will support increasing wind shear within the atmosphere today. This sheared environment will be supportive of rotating storms with damaging winds and the potential for a few tornadoes. At the present time the best chances for severe storms will be from Hernando county north to Levy County during the afternoon and evening hours where the best shear profiles will exist and the Storm Prediction Center has placed this region under a Slight Risk for severe weather through tonight, with a marginal risk of other severe storms from the Tampa Bay area south to Sarasota. In addition to the severe weather potential, some locally heavy rainfall amounts of one to one and half inches in some locations will be possible. Occasional lightning strikes will also accompany the storms. Impact 2: Strong Gusty Winds  Sustained northwest to north winds of up to 20 MPH with gusts as high as 35 MPH over land locations will be possible late tonight through Tuesday in the wake of the front, with the highest winds near the coast. Over the Gulf waters, sustained winds are expected to increase into the 25 to 30 knot range with gusts up to gale force at times tonight through early Wednesday. These strong winds will produce some very rough boating conditions for small craft operators. In addition the strong winds will help to build seas into the 8 to 10 foot range. The strong winds and building seas will support high surf and increasing wave action along area beaches along with a high risk for rip currents during Tuesday and NWS Tampa Bay Area Briefing for November 17, 2014 Page 2 of 4 Wednesday. The strong winds will also create hazardous boating conditions on area lakes, and a Lake Wind Advisory may be required on Tuesday. Impact 3: Freezing Temperatures  A much colder and drier air mass will move into all of West Central and Southwest Florida during Tuesday and Tuesday night on a brisk northwest to northerly wind flow. This much colder air mass will likely result in the first advective freeze event of the season across the Nature Coast late Tuesday night into early Wednesday morning where hard freeze and freeze watches are currently posted. Across the remainder of the region temperatures in the lower to mid-30s will be possible across central interior sections of Hillsborough, Polk, and Manatee counties with upper 30s to around 40 across southwest Florida, and lower 40s along the immediate coast. In addition elevated winds around 10 mph combined with the colder temperatures will likely produce low wind chill readings across the region late Tuesday night into early Wednesday morning.