PDC Weather Wall

May 2013
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There are no active tropical cyclones in the Pacific or Indian Oceans…or adjacent seas

PDC Global Hazards Atlas displaying 3 hour precipitation accumulation, with a tropical disturbance (circled in red) in the eastern Pacific Ocean…with a second disturbance circled in yellow to its west

Checking the Joint Typhoon Warning Center (JTWC), and the National Hurricane Center (NHC), neither of these agencies are carrying active tropical cyclones for their areas of responsibility. The picture above however, shows that the NHC is investigating two areas of disturbed weather. The first, the one circled in red, has a high 90% chance of developing, and is being called invest 92E . It is located about 200 miles south of Salina Cruz, Mexico, and is nearly stationary at the time of this writing. The various computer forecast models show where this area of low pressure could migrate with time…if it were to continue to develop further.

This first area of low pressure was located near 14N and 95.5W, south of the Gulf of Tehuantepec. Satellite imagery this morning shows that deep convection has increased. A very warm pool of warm tropical moisture resides in this area, providing a very moist and unstable unstable environment, in other words…very favorable conditions for development of a tropical cyclone. It is drifting very slowing towards the Mexican coast, thus the threat of showers and thunderstorms producing very heavy rainfall across the states of Chiapas and Oaxaca over the next several days.

The second area of disturbed weather, circled in yellow, is located about 850 miles south of the southern tip of Baja California. It has a low chance of developing into a tropical cyclone however…and will be slow to occur if at all. This area is being referred to as invest 91E, with the forecast models showing various movements.

PDC Global Hazards Atlas displaying 3 hour precipitation accumulation, with a tropical disturbance (circled in yellow) in the Bay of Bengal

Finally, at the same time, in the Bay of Bengal, there’s an area of disturbed weather located approximately 125 NM southeast of Kolkata, India. Satellite imagery shows a broad low level circulation center, with deep convective banding displaced over the southern periphery of this center…and fragmented banding elsewhere. The organization of these thunderstorms is weak, due to the system’s close proximity to land, and moderate to strong 20-30 knot (23-35 mph) vertical wind shear aloft.

Surface winds in association with this tropical disturbance are blowing 20-25 knots (23-29 mph). Weather models indicate a slight development as the system drifts slowly northward into Bangladesh during the next day or two. Due to these environmental factors, the Joint Typhoon Warning Center (JTWC) is giving only a low chance of this disturbance developing into a tropical cyclone.

Eastern North Pacific

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL

FOR THE EASTERN NORTH PACIFIC…EAST OF 140 DEGREES WEST LONGITUDE:

There are no current tropical cyclones

>SHOWER AND THUNDERSTORM ACTIVITY CONTINUES TO GRADUALLY INCREASE IN ASSOCIATION WITH A NEARLY STATIONARY AREA OF LOW PRESSURE LOCATED ABOUT 200 MILES SOUTH OF SALINA CRUZ MEXICO. THIS SYSTEM HAS THE POTENTIAL TO BECOME A TROPICAL DEPRESSION LATER TODAY…AND HAS A HIGH CHANCE…90 PERCENT…OF BECOMING A TROPICAL CYCLONE BEFORE IT REACHES THE COAST OF MEXICO IN A DAY OR TWO. INTERESTS ALONG THE SOUTHEASTERN PACIFIC COAST OF MEXICO SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM…AS TROPICAL STORM WARNINGS COULD BE REQUIRED WITH LESS THAN THE NORMAL AMOUNT OF LEAD TIME. REGARDLESS OF DEVELOPMENT…HEAVY RAINS ARE LIKELY OVER PARTS OF SOUTHERN MEXICO AND WESTERN CENTRAL AMERICA DURING THE NEXT FEW DAYS. THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.

AN AREA OF LOW PRESSURE LOCATED ABOUT 850 MILES SOUTH OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENNISULA IS PRODUCING DISORGANIZED SHOWERS AND THUNDERSTORMS. ANY DEVELOPMENT OF THIS SYSTEM SHOULD BE SLOW TO OCCUR…AND IT HAS A LOW CHANCE…10 PERCENT…OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS.

NHC graphical Tropical Weather Outlook Map

Eastern Pacific Satellite Image