Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
507 FXUS64 KBMX 100011 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 711 PM CDT Sun Jun 9 2024 ...New AVIATION... .MESOSCALE UPDATE FOR SEVERE THUNDERSTORM POTENTIAL... Issued at 431 PM CDT SUN JUN 9 2024 Severe thunderstorms are possible through 2am tonight for areas generally north of Interstate 85 and Highway 80. This covers roughly the northern two thirds of Central Alabama. Thunderstorms are expected to develop within the next few hours across western Alabama, Mississippi, and Arkansas. These storms will generally move east southeast through the evening. The atmosphere over the area is characterized by SBCAPE values ranging from 2500-4000j/kg, Effective Bulk Shear values up to 35kts, Downdraft CAPE 1100-1300j/kg, CAPE of 1000j/kg in the hail growth zone, but there is some drier air aloft and poor mid level lapse rates amongst others. The main thing we are missing at the present moment is a trigger. Convective temperatures are not enough alone to provide the forcing necessary for sustain updrafts at this time. A cold front was located over Tennessee and will only slowly move southward this evening. There are a few outflow boundaries out ahead of the front that will most likely be the focus for thunderstorm development as a short wave moves in this evening. It appears that if thunderstorms can become organized, they would move through later this evening with a threat of damaging wind gusts and large hail. But there remains some doubt as to which boundary or area of sustained thunderstorms will develop and where. A watch has been posted for areas west of us and we are monitoring the this activity for possible watches or warning later. It also appears that the upper ridge does recede southward enough for some development too. Made some minor adjustments to the ongoing forecast but nothing that alters the main message. 75 && .SHORT TERM... (This evening through Monday) Issued at 146 PM CDT SUN JUN 9 2024 Key Messages: - Conditional risk for shower and thunderstorm activity through tonight, some storms may be severe with a damaging wind and hail risk. Tonight. Another shortwave impulse associated with a longwave trough will drop southeast over the Mid-South Region this evening. This feature is supporting ongoing shower and thunderstorm activity across portions of Northeast Arkansas and Southeast Missouri. This activity will move east-southeast with time and it or its outflow may result in additional shower and thunderstorm development this evening and overnight with the nearing trough from the northwest and the advancing surface cold front that will be positioned roughly along the Interstate 20 corridor before midnight. Winds will become northwest behind the front with west winds persisting ahead of the front with speeds from 4-8 mph. Low temperatures will range from the mid 60s far northwest to the low 70s generally near and south of the U.S. Highway 80 corridor. Monday. The national flow pattern amplifies on Monday with longwave troughing over the Tennessee Valley extending northeast toward the upper low located just northeast of Maine while ridging builds over much of the Plains. The surface cold front will continue to advance south toward the Gulf Coast through the day. Decreasing clouds are forecast across the northwest half of the area while lingering clouds with chances for shower and thunderstorm activity will continue across the southern half of the area through the morning hours, becoming increasingly confined to the far southeast counties after noontime. Dry conditions will return areawide by the evening hours. Winds will be from the northwest areawide with speeds from 5-10 mph. High temperatures will range from the low 80s far north and in the higher elevations east to readings around 90 across the far southeast counties. 05 && .LONG TERM... (Monday night through next Saturday) Issued at 146 PM CDT SUN JUN 9 2024 The main focus during the week will be on increasing heat and potential heat-related impacts as we reach the warmest temperatures so far this year towards the end of the week. Upper-level troughing over the Southeast and a large region of high pressure over the Central US will drive northeasterly flow across Central Alabama and highs in the mid 90s. Otherwise, the forecast remains dry for much of the earlier half of the week with small opportunities for rain across the far south related to inverted troughing over the eastern Gulf of Mexico. 86/Martin Previous long-term discussion: (Monday night through Saturday) Issued at 353 AM CDT SUN JUN 9 2024 A significant upper-level trough east of the Mississippi River and the associated confluence zone will support relative high pressure moving southward into the Ohio Valley and southern states. A cooler and much drier airmass will be advected from the north Monday night with lows ranging from the upper 50s to the mid 60s from north to south. Dry conditions and low relative humidity values should continue Tuesday and Wednesday as high pressure remains in control under northwesterly flow at 500 mb. While moisture will gradually increase Thursday through Saturday, the arrival of increased rain chances could be delayed. Models are trending toward more ridging across the Deep South, keeping a disturbance in the Gulf of Mexico south of our area through Saturday. Our latest forecast significantly undercuts the NBM POPs Thursday through Saturday, and it is possible that most of the forecast area remains dry. 87/Grantham && .AVIATION... (00Z TAFS) Issued at 705 PM CDT SUN JUN 9 2024 All terminals start VFR. There are several small scale boundaries that may produce storm initiation early this evening. Mentioned varying degrees of thunder for several hours at the northern terminals with ceilings eventually into MVFR and possibly IFR at times. The timing and placement of convective development at the southern sites was less clear and mentioned only PROB30 on Monday for now. If the storms organize north, an update for storms may become necessary. A cold front will move north to south over the area later tonight into Monday with winds becoming north to northwest 5-10kts and rain chances becoming confined to the south. Some of the storms tonight may produce damaging winds and large hail. 75 && .FIRE WEATHER... Afternoon minimum RHs are forecast to remain above critical levels over the next few days. Overnight RH recovery should be in the upper 70s to low 90s. 20-foot winds should run at or less than 7 mph over the next few days, west-northwesterly today, and northerly on Monday. Some showers and thunderstorms may occur late this afternoon into tonight as a front moves across the area. Additional isolated to scattered showers are possible Monday afternoon across the southern half of the area as the front finally clears the area. Dry weather is expected from Tuesday through at least Thursday. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 67 83 57 84 / 40 20 0 0 Anniston 67 83 58 85 / 40 20 0 0 Birmingham 68 84 61 85 / 60 20 0 0 Tuscaloosa 70 86 61 86 / 60 20 0 0 Calera 68 85 62 85 / 60 20 0 0 Auburn 70 86 65 86 / 40 30 10 0 Montgomery 72 87 66 87 / 30 30 10 0 Troy 71 89 66 88 / 20 50 20 10 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...05 LONG TERM....86/Martin AVIATION...75