Tropical Update. 1 PM EDT Monday, May 21, 2018 Caribbean Disturbance (20%)

Transcription

1 Tropical Update 1 PM EDT Monday, May 21, 2018 Caribbean Disturbance (20%) This update is intended for government and emergency response officials, and is provided for informational and situational awareness purposes only. Forecast conditions are subject to change based on a variety of environmental factors. For additional information, or for any life safety concerns with an active weather event please contact your County Emergency Management or Public Safety Office, local National Weather Service forecast office or visit the National Hurricane Center website at

2 Atlantic Basin Satellite Image

3 1. Widespread cloudiness and showers extending from the northwestern Caribbean Sea across Cuba and the Florida peninsula are associated with the interaction of a large upperlevel low with a weak surface trough. While environmental conditions are expected to be unfavorable for development during the next couple of days, some gradual development is possible later this week while the system moves into the central or eastern Gulf of Mexico. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 5 days...low...20 percent.

4

5 Satellite Image Cuba Yucatan Peninsula The low pressure area is broad and thunderstorms are very disorganized. Most of the thunderstorm activity is displaced well to the east.

6 Western Atlantic Surface Map

7 Steering Currents A large high pressure system near Bermuda will steer the weak area of low pressure north from the western Caribbean to the Gulf of Mexico over the next five days. The system will eventually be brought into the Gulf Coast over the holiday weekend.

8 Surface Weather Maps for Friday (Left), Saturday (Middle), and Sunday (Right) Rain/Thunderstorms The system will drift north into the Gulf of Mexico Thursday or Friday. The system will continue to track north and may end up anywhere from Louisiana to South Florida. The system is likely to be large and lopsided and result in increased rain chances across the state even if the system tracks west.

9 Current Wind Shear (shaded) and Shear Tendency (lines) Wind shear across nearly the entire Gulf of Mexico is high. While wind shear will decrease some over the next few days, it will remain moderate which will limit development and keep the system lopsided with most of the rain on the eastern side.

10 Water Temperatures 83 F 80 F 77 F Water temperatures across the northeastern Gulf of Mexico are marginal and will only support minimal tropical development (depression or tropical storm).

11 Forecast Total Rainfall Accumulation Next 7 Days (Through Sunday) Daily rain chances can be expected across the state through the week. Regardless of development another surge of tropical moisture is expected this weekend. Daily rainfall totals of with locally higher amounts of day localized rainfall amounts may be 8-12.

12 Rivers across the state are starting to rise from recent rainfall. Most are now out of the low water levels they have been in for the last couple of months. Minor Flooding is expected along the following rivers for the next few days: Alafia Lithia Little Manatee Wimauma Myakka Myakka Head Horse Arcadia

13 Rip current risk today, which will likely continue at a similar threat through the week.

14 Summary A broad area of low pressure in the western Caribbean will slowly drift north into the Gulf of Mexico over the next week. The system may gradually become more organized during the next five-six days and develop into a subtropical or tropical depression or storm by the start of the Memorial Day Weekend. Moderate to high amounts of winds shear and marginal water temperatures are likely to limit the development of the system. The National Hurricane Center currently has the odds of develop at near 0% (low) during the next 48 hours, and 20% (low) during the next 5 days. Individual computer models have not been run on this disturbance as it is not designated as an invest area. This will remain the case unless development chances increase. Florida Outlook: Tropical moisture remains in place across the state and higher than normal rain chances will continue this week before the system arrives this weekend. Regardless of development, another surge of tropical moisture is expected this weekend across the state. Rain totals each day will generally be However, locally higher amounts of 2-4+ are possible. Where exactly this system tracks will depend on how much and where additional rain will fall this weekend. Cumulative rainfall totals through the next week will range from 3-6 with locally higher amounts of The ground is becoming saturated in many locations and flooding is becoming a bigger concern and will likely be the main threat from this system. Minor river flooding is expected for the next few days at several Southwest Florida rivers. With breezy onshore winds and a moderate swell, the rip current risk at most Atlantic and Panhandle beaches will be moderate to high through this week. Another briefing packet will be issued tomorrow morning. For the latest information on the tropics, please visit the National Hurricane Center website at

15 Tropical Update Created by: Michael Spagnolo, Deputy State Meteorologist State Meteorological Support Unit Florida Division of Emergency Management Users wishing to subscribe (approval pending) to this distribution list, register at _Tropics. Other reports available for subscription are available at