Jason's Weather Website

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Welcome to Jason's Weather Website

Welcome to my website. This website is run by Jason Godwin, a second-year meteorology graduate student at the University of Miami. On this website, you will find blog articles on various high-impact weather events, weather maps, links, and some of my research projects. All opinions on this website are my own.

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  • Slight risk for large hail and damaging winds over southwestern Florida on Thursday.

Synopsis: 24 February 2014

A few scattered thunderstorms will be possible along the sea breeze in south Florida today, a few of which could become strong. On Tuesday, a cold front will push into the south, with showers and thunderstorms expected to develop along and ahead of it, though at this time, severe thunderstorms are not anticipated. Cooler and drier weather can be expected in the middle part of the week with a warming trend beginning late in the week. Heading into the weekend, the long-range GFS model is hinting at a possible winter weather event for Oklahoma and the Texas Panhandle, but the details of this will not be very clear for another few days.

Another round of winter weather for the Gulf Coast

27 January 2014 - 21:55 GMT (4:55 p.m. EDT)

After last week's winter storm along the Gulf Coast, it appears that a second winter storm is on its way for Tuesday and Wednesday, with the Lower Mississippi Valley being impacted on Tuesday and then the southeast being impacted on Wednesday.

Looking at the synoptic setup, a powerful Arctic cold front is currently making its way through the southeast (current temperature map). The freezing line is expected to push all the way down to the Gulf Coast by daybreak Tuesday. For New Orleans, temperatures should be belowing freezing by 6 AM Tuesday with freezing rain beginning to accumulate.

Figure 1: GFS Forecast sounding for New Orleans, LA valid at 6:00 AM CST 1/28/2014 (source: NOAA BUFKIT)

Figure 1 shows a shallow freezing layer to about 2000 feet (the altitude lines represent thousands of feet here instead of the traditional pressure altitude) with a warm layer above that which is about 8000 feet deep. This is a classic freezing rain sounding where we'd expect snow growth to occur at around 20,000 feet, fall and melt at around 10,000 feet, then probably not quite have enough time to re-freeze before making contact with the surface (though if it does re-freeze, then it would be sleet instead of freezing rain). Later in the day Tuesday, the warm layer will likely cool enough to cause the precipitation to change over to sleet, and possibly snow right before the precipitation comes to an end Tuesday night. Most accumulations in New Orleans are expected to be freezing rain and/or sleet, with maybe just a dusting of snow. The GFS model is a lot more bullish with the freezing rain forecast, showing up to a half inch of ice accumulation, while the NAM model backs down to about a quarter of an inch, but even a quarter of an inch is enough to cause some scattered power outages and tree damage. The National Weather Service seems to agree with this forecast for New Orleans of 0.25-0.50 inches of ice.

The largest accumulations of freezing rain with this event are expected to be much farther east along the Georgia and South Carolina coasts where the largest amount of moisture is expected to be. The forecast soundings for Charleston, SC show below freezing temperatures by about 4 PM Tuesday. The forecast sounding for Charleston, SC at that time (Figure 2) is also a very classic freezing rain sounding.

Figure 2: GFS forecast sounding for Charleston, SC valid at 4:00 PM EST 1/28/2014 (source: NOAA BUFKIT)

The Charleston forecast sounding is probably an even better freezing rain sounding than the one for New Orleans since it has a very shallow freezing layer (as mentioned earlier, the freezing layer at the surface in New Orleans is possibly deep enough for sleet, but is very borderline). We can also see that on the Charleston sounding, the temperature (red) and dewpoint (green) lines are closer together than on the New Orleans sounding, indicating a more saturated profile (and thus why more precipitation is forecast along the Carolina coasts than southeast Louisiana). Both the GFS and NAM seem to be locked in on about 0.80 inches of freezing rain for Charleston, which could be very damaging should it verify. This kind of ice accumulation is what can lead to substantial power outages and tree damage in the area.

Figure 3: Probability of at least 1/4-inch of freezing rain/ice accumulation ending 7 PM EST Thursday (source: NWS Weather Prediction Center)

Probabilistic forecasts from the NWS indicate that there is a greater than 50% chance of 1/4-inch or more of ice accumulation over eastern Georgia and along the coast of South Carolina with at least of a tenth of an inch also possible across south-central and southeastern Louisiana (including Lafayette, Baton Rouge, and New Orleans), southern Mississippi, southern Alabama, southern Georgia, and the inland western Florida Panhandle.

On to the snow forecast, the probabilistic forecasts from the NWS (Figure 4) show that there is a 50% chance for four or more inches of snow across northern South Carolina (including Columbia and Florence) and eastern and central North Carolina (including Raleigh/Durham, Charlote, and Fayetteville) and a 50% chance for eight or more inches of snow across northeastern North Carolina (including Greenville and Elizabeth City). Additionally, there is a 50% chance of at least two inches of snow across much of the rest of inland South Carolina (including Greenville/Spartanburg) and central Georgia (including Atlanta, Augusta, and Athens).

Figure 4: Probability of at least four inches of snow accumulation ending 7 PM Thursday (source: NWS Weather Prediction Center)

The forecast sounding for Raleigh, NC show that temperatures should fall below freezing by 10 PM tonight, but the atmosphere will still be somewhat dry with the moisture starting to arrive by 1 PM on Tuesday. The forecast sounding below (Figure 5) shows very large vertical motion and plenty of moisture in the snow growth zone (the highlighted area around 15,000 feet), indicating a strong possibility for locally heavy snow. Both the GFS and the NAM are in agreement with about five inches of snow for the Raleigh/Durham area.

GFS forecast sounding for Raleigh, NC valid at 4:00 PM EST 1/28/2014 (source: NOAA BUFKIT)

To wrap up, freezing rain is expected to be the primary precipitation along the Gulf Coast and the Georgia and South Carolina coasts with snow expected farther inland, especially over inland South Carolina, North Carolina, and Georgia. Some areas, particularly those in coastal Georgia and South Carolina, could see significant freezing rain accumulation leading to power outages and tree damage. The event is expected to start tonight for the Gulf Coast and Tuesday afternoon for the Carolinas before winding down Tuesday night/Wednesday morning for the Gulf Coast and Wednesday evening for the southeast.

Current Conditions

Sea-Level Pressure 10-meter winds Surface temperature Surface dewpoint

Continental U.S. Radar Mosaic

Continental U.S. Infrared Satellite

Current Temperatures

Atlantic Tracking Chart

Tropical Atlantic Infrared Satellite

Tropical Atlantic & Eastern Pacific Surface Analysis