National Weather Service United States Department of Commerce

Powerful Winter Storm from the Upper Midwest into the Northeast; Severe Thunderstorms in the Midwest and Ohio Valley

A rapidly-intensifying storm is expected to bring heavy snow, blizzard conditions, and icing from the Upper Midwest through the Great Lakes and Northeast. Scattered severe thunderstorms may produce severe/damaging wind gusts and a couple of tornadoes across parts of the Midwest and lower Ohio Valley through the evening. Arctic air will expand across the central and southern U.S.. Read More >

 Louisiana and Southeast Texas
Fog Research and Modeling

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Statistics

Total fog days starting June 1999 ending June 2000 = 51

Table 1- Purely radiation fog days and radiation fog produced with other types of fog
Radiation Fog Days = 19 days (37.3 %)
 
Purely radiation 14 days
Frontal-induced radiation 6 days
Marine-induced radiation 1 day

 

Table 2- Purely marine Fog days and marine fog produced with other types of fog
Marine Fog Days = 20 days (39.2 %)
 
Purely marine advection 4 days
Frontal-induced marine 7 days
Frontal-induced with marine deck 6 days
Low deck-initiated marine 18 days
Radiation-induced marine 1 day

 

Table 3- Purely frontal fog days and frontal fog with other types of fog
Frontal Fog Days = 6 days (11.8 %)
 
Purely frontal 2 days
Frontal with radiation influence 6 days
Frontal with marine influence 6 days

 

Table 4- Purely advection fog days and advection fog with other types of fog
Advection Fog Days = 6 days (11.8 %)
 
Advection from the northeast or east 2 days
Advection from the west 3 days
Advection as a deck 1 day
Frontal-induced advection 2 days

 

Individual Parameter Statistics

Surface pressure related to fog formation in Southwest Louisiana and Southeast Texas (in millibars)

1009: 1 1016: 6 1024: 1
1010: 1 1017: 5 1025: 1
1011: 0 1018: 8 1026: 1
1012: 0 1019: 6 1027: 0
1013: 0 1020: 6 1028: 1
1014: 2 1021: 1 1029: 0
1015: 2 1022: 4 1030: 2
  1023: 3  

A fascinating thing was found in the pressure field. Between 1016 - 1023mb, there were 39 days (76.5 %) of fog. Between 1018 - 1020mb, there were 20 days (39.2 % ) of fog. 40% of all fog days fell within pressures of only 2 millibars. Over 3/4 of all fog days fell within pressures of 7 millibars. These findings were significant and were incorporated in the model as well.

High pressure centers related to fog formation in Southwest Louisiana
and Southeast Texas

 

Fog paper image

High pressure centers were located over the North Atlantic, East Coast States, Gulf States and Gulf of America during 40 fog days (78.4 %). Other locations not including the aforementioned were found eastward of a line from Wichita Falls, Texas to Duluth, Minnesota. These locations comprised of 9 fog days (17.6 %). Only 2 fog days showed high pressure centered outside these areas.


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