Winter Returns Across the Northern Tier; Record Warmth for the Southwest

A large high pressure system will usher in cold air for this first day of March across the northern Plains, Great Lakes, Northeast and mid-Atlantic. Some wintry precipitation may evolve across the mid-Mississippi Valley, Ohio Valley and mid-Atlantic through Monday. Meanwhile, record warmth will spread across the Southwest, southern Plains through early this week. Read More >

Louisiana and Southeast Texas
Fog Research and Modeling
(continued)

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

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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Winter Returns Across the Northern Tier; Record Warmth for the Southwest

Research Studies