Archive for the ‘Flooding’ Category

Rainfall is ongoing across portions of Alabama along the state line at this hour, but the rainfall is expected to pick up this afternoon.  Another wave of energy in the upper air will swing in and cause more widespread showers and thunderstorms to develop across the area through the early part of the day tomorrow.   Some river flooding could become a problem across western sections of the area.  Temperatures across the northern 2/3 of Alabama will remain too stable for any kind of severe activity….but things along the Gulf Coast could crank up later as the shortwave moves closer. 

The SPC upgraded a portion of the outlook area along the Gulf Coast to a slight risk around 10am this morning for the overnight hours tonight.  Shear will increase ahead of a mid level wave….as will some weak instability which could lead to a few damaging wind gusts and/or brief tornadoes.  The risk runs roughly from Mobile to Dothan and southward. 

We will likely release a full summary on the December 22nd QLCS/low topped supercell tornado event in the coming days as we get video and pictures together of the happenings of that day.  Look for it in future postings. 

The HPC now puts some rather hefty rainfall totals across portions of Alabama into the weekend and next week.  Currently….the NHC continues to hold at Tropical Depression status.  There continues to be a high likelihood that Lee will be born sometime in the next 12 hours.  We will update more as information becomes available…

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE
NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM.

.DAY ONE…TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN…FRIDAY THROUGH WEDNESDAY.

ANOTHER ROUND OF SEVERE WEATHER WILL BE POSSIBLE FROM SATURDAY
AFTERNOON THROUGH SUNDAY AFTERNOON AS A COLD FRONT TRIES TO WORK
THROUGH THE AREA. THERE ARE STILL SOME TIMING AND STRENGTH
ISSUES…BUT CHANCES ARE INCREASING FOR THE CHANCE AT SEEING
DAMAGING WINDS…HAIL…AND HEAVY RAINFALL OVER THE WEEKEND. STAY
TUNED FOR THE LATEST UPDATES AS WE GET CLOSER TO THE WEEKEND.

.SPOTTER INFORMATION STATEMENT…

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT IS NOT
EXPECTED AT THIS TIME.

This is video that I shot earlier today during the heavy rainfall as it was unfolding.  Flood waters trapped people in there homes and started rising toward the doors of some vehicles.  River flooding is also prevalent across many areas this afternoon. 

Flooding is taking place across a large section of the area now.  We will be streaming live within the hour from some flooded areas.  We have seen upwards of 3’ of water in some locations off of HWY-280 in Childersburg.  We will be streaming live at StormScapeLIVE.com across portions of Talladega county where some flooding is ongoing.

Heavy rains are beginning to spread northeastward across portions of Central Alabama with the heaviest over southwestern sections of our viewing area in the Sumter, Greene, Perry, Hale, Pickens, and Dallas County areas.  Some areas of localized flooding have already been reported with the rainfall during the afternoon with earlier storms due to swollen creeks and streams from the last widespread rain event a few days ago.

Rain is expected to spread and intensify across the entire area with some of the rainfall being convective in nature.  Most of the region will see a good 2”+ rainfall event from this with more coming tomorrow.  Flash flood watches are already in effect and warnings are quite possible if this event becomes prolonged.  Rainfall will be moderate to heavy for most areas during the night tonight.

There could be a break in the action ahead of the cold front tomorrow before more showers and storms impact the area.  This will be key in terms of how much instability develops across the area and we will be monitoring this frontal progression throughout the night time hours.  CAPE values are climbing to our south in a hurry just south of the front…..on the order of 2000 joules of MLCAPE.  If these kind of values end up progressive into Alabama….we will have a definite severe storm and tornado threat.  We will keep you updated…

Storms are increasing this afternoon on the warm conveyor belt aloft north of the warm front.  This is causing some storms to develop with some hail in the strongest updrafts.  These storms don’t have the potential to become tornadic due to no low level instability.  These cells are all elevated in nature.  Heavy rainfall could become a problem by later tonight and a Flash Flood Watch has been placed for much of the area. 

we continue to watch the potential for some severe storms on tomorrow as the slight risk has been nudged northward again toward the Montgomery area.  Damaging winds and isolated tornadoes look to be the main threats due to the moist environment ahead of the system and high low level shear values.  Heavy rainfall could be the biggest threat of everything with this system.  We will continue to monitor it.

Looks like we will get started fairly fast this weekend with showers and storms already taking place across a good portion of the lower Mississippi Valley this evening.  Tomorrow….some localized areas of flooding are possible ahead of the cold frontal boundary as pockets of heavy rainfall setup during the day.  Some isolated severe weather will be possible in areas where instability values can creep up, but a good chunk of Alabama will deal with easterly winds of the wedge boundary which will keep temperatures cooler east of I-65 and instability in check.  The best chance of any severe storms will be to the west and south over portions of coastal Mississippi, Louisiana, and Alabama where some marine air could spark some severe weather. 

Model output does indicate some areas receiving over 3” of rainfall north of I-20/59 during the overnight tonight and day tomorrow.  With the drought stricken conditions across a good portion of the area, flooding will not be a widespread problem unless some 5”+ totals are reached in a 12 hour period.  This does not look likely, but we will definitely watch the trends and training of cells within the rain shield.

We are beginning to worry a little more about Wednesday as a very dynamic system will take shape to our west and put is back in the warm sector yet again as a cold front heads our way.   There are questions regarding the timing and moisture quality that returns ahead of the system.   If things continue to trend toward more return flow….we will likely be dealing with a tornadic type event.  Stay tuned as we will be updating the chase status during the next couple of days to reflect on this.  Enjoy your wet start to the weekend with a movie and some relaxation like I am.

This is the rainfall forecast thru late Wednesday…..showing well over an inch south of the I-20 corridor.  I believe that the percentages are high enough for me to forecast mostly rain for the area.  I could see some regions locally seeing 2-3” totals from the heavy rain making surface low due to come out of the Gulf of Mexico.  Someone will probably see a transition to some snowfall in the north, but the main dynamics don’t look as strong on recent model runs and I feel more comfortable saying that most of the area will be too warm for snow accumulations.  There is still some time left for things to change on the model data as the system enters our upper air network, but we certainly don’t need to modify over the next two days very much. 

Expect temperatures in the 40’s during the rainfall falling into the mid 30’s during the overnight periods.  Drier weather for the end of the week…

Rainfall amounts of 1-2” are pretty common thus far across Central sections of the state with much greater totals NW of I-20/59.  The severe weather threat for the area has all but ended as the rainfall has saturated us pretty well.  It looks as if the situation potential that we posted last night was pretty true……in terms of our severe weather thoughts.  So, we faired pretty well besides some sporadic wind damage and flooding issues.  The rain is currently ending from a line of Livingston – Tuscaloosa – Birmingham – Gadsden and northwest. 

The cold frontal boundary will push much cooler air into the region later on today.  Dewpoints have already dropped into the low to mid 20’s across Mississippi.  Lows tonight will fall to near freezing NW of I-20/59 with mid 30’s to mid 40’s in the southeast. 

We will have more on yesterdays tornadoes in a post later on.  Preliminary data shows that it was the largest tornado outbreak in New Years Eve history.  More to come…