quiver vectors not showing correctly when overlaid on contourm map

Hello all,

I am having a problem overlaying quiver vectors on top of contourm map. When I plot the vectors separately from the contourm map I get Figure1 (attached), but when I overlay on the contourm I get partial vectors (attached as Figure2). I am not sure what is going on. Do I have to put the vectors on a separate axes? Any help with this is appreciated.

Here is my code: 
figure
axesm miller
setm(gca,'origin',[0 360])
setm(gca, 'Origin', [0 180 0])
setm(gca,'mlabelparallel',-90)
setm(gca,'Fontsize',5)
s=shaperead('landareas.shp','UseGeoCoords',true);
tightmap
caxis([0, 100]);
contourm(latlim,lonlim,Final','Fill','on');
colormap(jet)
coast = load('coast');
geoshow(coast.lat, coast.long,'Color', 'black')
hold on
quiver(a1,b1,ix,iy,'color',[0 0 0],'Linewidth',1)