Clouds have been on the increase this Saturday with moisture
levels on the rise under breezy southerly wind. Moisture is increasing ahead a
cold front moving southeast out of the Central Plains states, headed for the Mid-South.
The front will approach the region Sunday, but like we saw with our previous
cold front earlier in the week, it will not sweep through very quickly at all.
In fact, the front will stall just north of our area, resulting in extended
rain chances that will continue through late Tuesday, with periods of heavy
rainfall and thunderstorms possible.
Though the regional radar is dry as of Saturday afternoon,
expect that to be changing soon. Rain will begin breaking out ahead of the
front after midnight across Arkansas and Missouri, slowly pushing southeast. This
first round of rain will impact the metro during the day Sunday. At the same
time, the front is expected to stall just north of the region. As
this happens, repeated upper level disturbances will track along the stalled surface
boundary, resulting in additional rounds of rain that will continue into Monday.
After a brief break late Monday into
early Tuesday, a final and much stronger upper level disturbance will move in
from the southwest, resulting in the development of surface low pressure that will move just north of the region, finally sweeping the cold front through by Tuesday evening.
This will lead to the final round of rain for the metro area.
Though confidence is high that the front will stall
somewhere just north of the area on Sunday, exactly where that happens remains
uncertain, which will be key to what parts of the metro see the heaviest
rainfall amounts during this period. At this time, the latest computer model
guidance indicates the front’s stall will occur near the Arkansas/Missouri
border. Should this happen, the steadiest and heaviest rain would be north
of Interstate 40, while areas to the south may have more extended dry periods and thus lesser rainfall amounts, especially between Sunday and Monday when the
front is stalled. This would be quite
similar to the situation earlier in the week with our previous system.
The most significant hazardous weather threat during this
period will be heavy rainfall. In general, 1 to 4 inches of rainfall can be
expected across the metro between Sunday and Tuesday. However, areas north
of Interstate 40, closer to the stalled front, may see even higher amounts,
with totals up to 6 inches possible. In
these areas, specifically across Crittenden and Tipton Counties (which also saw
the heaviest rainfall earlier in the week), a threat of flash flooding may
develop. Therefore, a Flash Flood Watch has been issued by the National Weather
Service from Sunday night through Tuesday afternoon. Across the remainder of
the metro, even though a widespread flooding threat is currently not
anticipated, some issues with standing water may still develop, especially in
flood-prone areas. No matter where you are, if you encounter a flooded roadway,
as the National Weather Service says: Turn Around, Don’t Drown!
 |
| National Weather Service forecast precipitation between Sunday and Tuesday, indicating rain amounts of 1 to 3 inches in the metro. Higher amounts are possible north of Interstate 40. |
In addition to the heavy rain and flooding potential,
thunderstorms are possible as well during this period. The best threat for storms is expected to be with the final round of rain on Tuesday, with a band of thunderstorms
likely to sweep through ahead of the cold front. As is typical during the fall
season, the amount of expected instability is in question, but strong wind
dynamics will be in place. Nevertheless, some strong thunderstorms may occur. A
better assessment of this potential will be possible closer to Tuesday itself,
as more computer model data will be available.
 |
| GFS model forecast for Tuesday morning (11/22), depicting a low pressure area to our NW, which will help sweep the cold front and a final band of rain and thunderstorms through the region. |
Stay with MemphisWeather.Net for the very latest information
on the heavy rain and thunderstorm threat as it evolves over the next few days.
Our MWN Storm Center
and forecast page
will have full and updated details, with social media nowcasting on Facebook and Twitter expected as well.
--Kevin Terry, MemphisWeather.Net
----For weather information for Memphis and the Mid-South, where and when you need it, visit MemphisWeather.net on the web, m.memphisweather.net on your mobile phone, download our Android app, or visit us on Facebook or Twitter.
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